text:
Michel Digonnet
Professor (Research) of Applied Physics
Professor (Research), Applied Physics
2021-22 Courses
Independent Studies (3)
Directed Studies in Applied Physics
APPPHYS 290 (Aut, Win, Spr, Sum)
APPPHYS 291 (Sum)
PHYSICS 490 (Aut, Win)
Stanford Advisees
Doctoral Dissertation Reader (AC)
Hrishikesh Srinivas
Doctoral Dissertation Advisor (AC)
Matt Grant, Behrad Habib Afshar, Jonathan Wheeler, Adele Zawada
Doctoral (Program)
Grace Woods
Predictive comparison of anti-Stokes fluorescence cooling in oxide and non-oxide fiber hosts doped with Er3+ or Yb3+ Balliu, E., Thontakudi, A., Knall, J. M., Digonnet, M. F., Seletskiy, D. V., Epstein, R. I., SheikBahae, M. SPIE-INT SOC OPTICAL ENGINEERING. 2019
View details for DOI 10.1117/12.2510859
View details for Web of Science ID 000468075900009
Experimental investigations of spectroscopy and anti-Stokes fluorescence cooling in Yb-doped silicate fibers Knall, J. M., Arora, A., Dragic, P., Ballato, J., Cavillon, M., Hawkins, T., Jiang, S., Luo, T., Bernier, M., Digonnet, M., Seletskiy, D. V., Epstein, R. I., SheikBahae, M. SPIE-INT SOC OPTICAL ENGINEERING. 2019
High-resolution slow-light fiber Bragg grating temperature sensor with phase-sensitive detection OPTICS LETTERS Arora, A., Esmaeelpour, M., Bernier, M., Digonnet, M. F. 2018; 43 (14): 3337–40
This Letter reports a slow-light fiber Bragg grating (FBG) temperature sensor with a record temperature resolution of ∼0.3 m°C/√Hz, a drift of only ∼1 m°C over the typical duration of a measurement (∼30 s), and negligible self-heating. This sensor is particularly useful for applications requiring the detection of very small temperature changes, such as radiation-balanced lasers and the measurement of small absorptive losses using calorimetry. The sensor performance is demonstrated by measuring the heat generated in a pumped Yb-doped fiber. The sensor is also used to measure the slow-light FBG's very weak internal absorption loss (0.02 m-1), which is found to be only ∼2% of the total loss.
View details for DOI 10.1364/OL.43.003337
View details for PubMedID 30004500
Double-Ring Resonator Optical Gyroscopes JOURNAL OF LIGHTWAVE TECHNOLOGY Grant, M. J., Digonnet, M. F. 2018; 36 (13): 2708–15
View details for DOI 10.1109/JLT.2018.2818754
In-situ fiber temperature sensor for anti-Stokes cooling measurements in doped fibers Arora, A., Esmaeelpour, M., Knall, J. M., Freniere, J., Boilard, T., Bernier, M., Digonnet, M. F., Epstein, R. I., Seletskiy, D. V., SheikBahae, M. SPIE-INT SOC OPTICAL ENGINEERING. 2018
Double-ring optical resonator gyroscopes using 3x3 fiber couplers Grant, M. J., Digonnet, M. F., Shahriar, S. M., Scheuer, J. SPIE-INT SOC OPTICAL ENGINEERING. 2018
Model of anti-Stokes cooling in a Yb-doped fiber Knall, J., Esmaeelpour, M., Digonnet, M., Epstein, R. I., Seletskiy, D. V., SheikBahae, M. SPIE-INT SOC OPTICAL ENGINEERING. 2018
Photonics sensing at the thermodynamic limit OPTICS LETTERS Skolianos, G., Arora, A., Bernier, M., Digonnet, M. J. 2017; 42 (10): 2018-2021
We report a slow-light fiber Bragg grating strain sensor with a resolution limited by the extremely low thermodynamic phase fluctuations of the fiber. This was accomplished by using a short grating (4.5 mm) to enhance the thermal phase noise, an ultra-stable interrogation laser to lower the laser frequency noise, and a slow-light mode with a high group index (∼533) to suppress all other noise sources. We demonstrate that in a similar but longer grating (21 mm), the phase noise is suppressed in inverse proportion to the square root of the length, in accordance with theory, leading to a strain resolution as low as 130 fε/√Hz and a minimum detectable length of ∼3×10-15 m at 1.5 kHz.
Aircraft-navigation-grade laser-driven FOG with Gaussian-noise phase modulation OPTICS LETTERS Chamoun, J., Digonnet, M. J. 2017; 42 (8): 1600-1603
A laser-driven fiber optic gyroscope (FOG) is demonstrated with an angular random walk noise of 5.5×10-4 deg/√h, a drift of 6.8×10-3 deg/h, and an inferred scale-factor stability of 0.15 ppm, making it, to the best of our knowledge, the first laser-driven FOG to satisfy the performance requirements for inertial navigation of commercial aircraft. This is achieved using Gaussian white noise phase modulation to broaden the linewidth of the source laser and to strongly suppress the narrow-linewidth optical carrier. The performance of this laser-driven FOG is shown to have better noise and only slightly higher drift than the same FOG driven by a conventional superfluorescent fiber source. This result is validated for two lasers with widely different intrinsic coherence.
Observation of thermodynamic phase noise using a slow-light resonance in a fiber Bragg grating Skolianos, G., Arora, A., Bernier, M., Digonnet, M., Shahriar, S. M., Scheuer, J. SPIE-INT SOC OPTICAL ENGINEERING. 2017
Pseudo-random-bit-sequence phase modulation for reduced errors in a fiber optic gyroscope OPTICS LETTERS Chamoun, J., Digonnet, M. J. 2016; 41 (24): 5664-5667
Low noise and drift in a laser-driven fiber optic gyroscope (FOG) are demonstrated by interrogating the sensor with a low-coherence laser. The laser coherence was reduced by broadening its optical spectrum using an external electro-optic phase modulator driven by either a sinusoidal or a pseudo-random bit sequence (PRBS) waveform. The noise reduction measured in a FOG driven by a modulated laser agrees with the calculations based on the broadened laser spectrum. Using PRBS modulation, the linewidth of a laser was broadened from 10 MHz to more than 10 GHz, leading to a measured FOG noise of only 0.00073 deg/√h and a drift of 0.023 deg/h. To the best of our knowledge, these are the lowest noise and drift reported in a laser-driven FOG, and this noise is below the requirement for the inertial navigation of aircraft.
Slow light in fiber Bragg gratings and its applications JOURNAL OF PHYSICS D-APPLIED PHYSICS Skolianos, G., Arora, A., Bernier, M., Digonnet, M. 2016; 49 (46)
View details for DOI 10.1088/0022-3727/49/46/463001
Observation of Unique Coupling-Independent Resonances in Coupled Spiral Resonators JOURNAL OF LIGHTWAVE TECHNOLOGY Guo, W., Digonnet, M. J. 2016; 34 (13): 3087-3093
Haltere-Like Optoelectromechanical Gyroscope IEEE SENSORS JOURNAL Kilic, O., Ra, H., Akkaya, O. C., Digonnet, M. J., Solgaard, O. 2016; 16 (11): 4274-4280
View details for DOI 10.1109/JSEN.2016.2539687
Photonic-Crystal-Based Fiber Hydrophone With Sub-100 mu Pa/root Hz Pressure Resolution IEEE PHOTONICS TECHNOLOGY LETTERS Jan, C., Jo, W., Digonnet, M. J., Solgaard, O. 2016; 28 (2): 123-126
View details for DOI 10.1109/LPT.2015.2487498
Highly Sensitive Phase-Front-Modulation Fiber Acoustic Sensor JOURNAL OF LIGHTWAVE TECHNOLOGY Jo, W., Kilic, O., Digonnet, M. J. 2015; 33 (20)
Fiber-feedback optical parametric oscillator for half-harmonic generation of sub-100-fs frequency combs around 2??µm. Optics letters Ingold, K. A., Marandi, A., Digonnet, M. J., Byer, R. L. 2015; 40 (18): 4368-4371
We demonstrate a femtosecond fiber-feedback optical parametric oscillator (OPO) at degeneracy. The OPO cavity comprises an 80-cm-long fiber composed of a combination of normal and anomalous dispersion sections that provide a net intracavity group delay dispersion close to zero. By using a mode-locked, Yb-doped fiber laser as the pump, we achieved half-harmonic generation of 250-MHz, 1.2-nJ nearly transform-limited 97-fs pulses centered at 2090 nm with a total conversion efficiency of 36%.
High Purcell factor in fiber Bragg gratings utilizing the fundamental slow-light mode OPTICS LETTERS Skolianos, G., Arora, A., Bernier, M., Digonnet, M. J. 2015; 40 (15): 3440-3443
Noise and Bias Error Due to Polarization Coupling in a Fiber Optic Gyroscope JOURNAL OF LIGHTWAVE TECHNOLOGY Chamoun, J. N., Digonnet, M. J. 2015; 33 (13): 2839-2847
Effect of periodic modulation of the coupling ratios on the sensitivity of a CROW gyroscope JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS Aghaie, K. Z., Digonnet, M. J. 2015; 32 (6): 1120-1124
View details for DOI 10.1364/JOSAB.32.001120
Slowing down light to 300 km/s in a deuterium-loaded fiber Bragg grating OPTICS LETTERS Skolianos, G., Arora, A., Bernier, M., Digonnet, M. J. 2015; 40 (7): 1524-1527
We report light propagation with a group velocity of only 300 km/s, a group index of 1010, and a group delay of 42 ns, in a strong apodized fiber Bragg grating 12.5 mm in length. The grating was fabricated in a deuterium-loaded fiber using a femtosecond laser and a phase mask, followed by annealing to reduce residual losses. Data analysis indicates a strong index modulation of 1.98×10(-3) and an ultra-low single-pass power loss of 0.010 dB.
Sensitivity limit of a coupled-resonator optical waveguide gyroscope with separate input/output coupling JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS Aghaie, K. Z., Digonnet, M. J. 2015; 32 (2): 339-344
Strong Slow-Light Resonances in Apodized Deuterium-Loaded Femtosecond Fiber Bragg Gratings Conference on Slow Light, Fast Light, and Opto-Atomic Precision Metrology VIII Skolianos, G., Arora, A., Bernier, M., Digonnet, M. J. SPIE-INT SOC OPTICAL ENGINEERING. 2015
Rotation sensitivity analysis of a two-dimensional array of coupled resonators Conference on Slow Light, Fast Light, and Opto-Atomic Precision Metrology VIII Aghaie, K. Z., Vigneron, P., Digonnet, M. J. SPIE-INT SOC OPTICAL ENGINEERING. 2015
Advances in 2-mu m Tm-doped mode-locked fiber lasers OPTICAL FIBER TECHNOLOGY Rudy, C. W., Digonnet, M. J., Byer, R. L. 2014; 20 (6): 642-649
View details for DOI 10.1016/j.yofte.2014.06.005
Coupled Spiral Interferometer Gyroscope JOURNAL OF LIGHTWAVE TECHNOLOGY Guo, W., Digonnet, M. J. 2014; 32 (22): 4360-4364
Coupled Spiral Interferometers JOURNAL OF LIGHTWAVE TECHNOLOGY Guo, W., Digonnet, M. J. 2014; 32 (21): 4162-4168
Piconewton force measurement using a nanometric photonic crystal diaphragm OPTICS LETTERS Jo, W., Digonnet, M. J. 2014; 39 (15): 4533-4536
A compact force fiber sensor capable of measuring forces at the piconewton level is reported. It consists of a miniature Fabry-Perot cavity fabricated at the tip a single-mode fiber, in which the external reflector is a compliant photonic-crystal diaphragm that deflects when subjected to a force. In the laboratory environment, this sensor was able to detect a force of only ∼4 pN generated by the radiation pressure of a laser beam. Its measured minimum detectable force (MDF) at 3 kHz was as weak as 1.3 pN/√Hz. In a quiet environment, the measured noise was ∼16 times lower, and the MDF predicted to be ∼76 fN/√Hz.
Thermal Sensitivity of the Birefringence of Air-Core Fibers and Implications for the RFOG JOURNAL OF LIGHTWAVE TECHNOLOGY Zhao, X., Louveau, J., Chamoun, J., Digonnet, M. J. 2014; 32 (14)
Observation of similar to 20 ns group delay in a low-loss apodized fiber Bragg grating OPTICS LETTERS Skolianos, G., Bernier, M., Vallee, R., Digonnet, M. J. 2014; 39 (13): 3978-3981
We report a record group delay of 19.5 ns (an equivalent group index of 292) measured in a strongly apodized, 2 cm long, femtosecond fiber Bragg grating (FBG). This significant (~4-fold) improvement over the previous record results from the presence of a Fabry-Perot arising from the apodization. The measured group-index spectrum is well explained by a model that accounts for the apodized profiles of the index modulation, propagation loss, and birefringence of the grating. The peak power loss inferred from this model is only ~0.12 m⁻¹, which is one of the lowest values reported for an FBG.
Thermal phase noise in Fabry-Perot resonators and fiber Bragg gratings PHYSICAL REVIEW A Skolianos, G., Wen, H., Digonnet, M. J. 2014; 89 (3)
View details for DOI 10.1103/PhysRevA.89.033818
Sensitivity analysis of linear CROW gyroscopes and comparison to a single-resonator gyroscope Conference on Advances in Slow and Fast Light VII Zamani-Aghaie, K., Digonnet, M. J. SPIE-INT SOC OPTICAL ENGINEERING. 2014
Low noise and low drift in a laser-driven fiber optic gyroscope with a 1-km coil 23rd International Conference on Optical Fibre Sensors Chamoun, J. N., Evans, A., Mosca, F. A., Digonnet, M. J. SPIE-INT SOC OPTICAL ENGINEERING. 2014
Miniature fiber acoustic sensors using a photonic-crystal membrane OPTICAL FIBER TECHNOLOGY Jo, W., Akkaya, O. C., Solgaard, O., Digonnet, M. J. 2013; 19 (6): 785-792
Time-Division-Multiplexed Interferometric Sensor Arrays JOURNAL OF LIGHTWAVE TECHNOLOGY Akkaya, O. C., Digonnet, M. J., Kino, G. S., Solgaard, O. 2013; 31 (16): 3001-3008
Modeling Coherent Backscattering Errors in Fiber Optic Gyroscopes for Sources of Arbitrary Line Width JOURNAL OF LIGHTWAVE TECHNOLOGY Lloyd, S. W., Digonnet, M. J., Fan, S. 2013; 31 (13): 2070-2078
Experimental Observation of Low Noise and Low Drift in a Laser-Driven Fiber Optic Gyroscope JOURNAL OF LIGHTWAVE TECHNOLOGY Lloyd, S. W., Fan, S., Digonnet, M. J. 2013; 31 (13): 2079-2085
Slow-Light Fiber-Bragg-Grating Strain Sensor With a 280-femtostrain/root Hz Resolution JOURNAL OF LIGHTWAVE TECHNOLOGY Wen, H., Skolianos, G., Fan, S., Bernier, M., Vallee, R., Digonnet, M. J. 2013; 31 (11): 1804-1808
Amplified 2-mu m Thulium-Doped All-Fiber Mode-Locked Figure-Eight Laser JOURNAL OF LIGHTWAVE TECHNOLOGY Rudy, C. W., Urbanek, K. E., Digonnet, M. J., Byer, R. L. 2013; 31 (11): 1809-1812
Experimental Assessment of the Accuracy of an Advanced Photonic-Bandgap-Fiber Model JOURNAL OF LIGHTWAVE TECHNOLOGY Aghaie, K. Z., Digonnet, M. J., Fan, S. 2013; 31 (7): 1015-1022
Modeling Loss and Backscattering in a Photonic-Bandgap Fiber Using Strong Perturbation Conference on Photonic and Phononic Properties of Engineered Nanostructures III Aghaie, K. Z., Digonnet, M. J., Fan, S. SPIE-INT SOC OPTICAL ENGINEERING. 2013
Compact Coupled Resonators for Slow-Light Sensor Applications Conference on Advances in Slow and Fast Light VI Guo, W., Digonnet, M. SPIE-INT SOC OPTICAL ENGINEERING. 2013
Modeling and Demonstration of Thermally Stable High-Sensitivity Reproducible Acoustic Sensors JOURNAL OF MICROELECTROMECHANICAL SYSTEMS Akkaya, O. C., Kilic, O., Digonnet, M. J., Kino, G. S., Solgaard, O. 2012; 21 (6): 1347-1356
View details for DOI 10.1109/JMEMS.2012.2196494
Resonant Fiber Optic Gyroscope Using an Air-Core Fiber JOURNAL OF LIGHTWAVE TECHNOLOGY Terrel, M. A., Digonnet, M. J., Fan, S. 2012; 30 (7): 931-937
Sensing With Slow Light in Fiber Bragg Gratings IEEE SENSORS JOURNAL Wen, H., Terrel, M., Fan, S., Digonnet, M. 2012; 12 (1): 156-163
Improving fiber optic gyroscope performance using a laser and photonic-bandgap fiber 22nd International Conference on Optical Fiber Sensors (OFS) Lloyd, S., Fan, S., Digonnet, M. J. SPIE-INT SOC OPTICAL ENGINEERING. 2012
Slow Light in Fiber Sensors Conference on Advances in Slow and Fast Light V Digonnet, M. J., Wen, H., Terrel, M. A., Fan, S. SPIE-INT SOC OPTICAL ENGINEERING. 2012
View details for DOI 10.1117/12.915293
Rotation Sensitivity of Gyroscopes Based on Distributed-Coupling Loop Resonators JOURNAL OF LIGHTWAVE TECHNOLOGY Digonnet, M. J. 2011; 29 (20): 3048-3053
Miniature photonic-crystal hydrophone optimized for ocean acoustics JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA Kilic, O., Digonnet, M. J., Kino, G. S., Solgaard, O. 2011; 129 (4): 1837-1850
This work reports on an optical hydrophone that is insensitive to hydrostatic pressure, yet capable of measuring acoustic pressures as low as the background noise in the ocean in a frequency range of 1 Hz to 100 kHz. The miniature hydrophone consists of a Fabry-Perot interferometer made of a photonic-crystal reflector interrogated with a single-mode fiber and is compatible with existing fiber-optic technologies. Three sensors with different acoustic power ranges placed within a sub-wavelength sized hydrophone head allow a high dynamic range in the excess of 160 dB with a low harmonic distortion of better than -30 dB. A method for suppressing cross-coupling between sensors in the same hydrophone head is also proposed. A prototype was fabricated, assembled, and tested. The sensitivity was measured from 100 Hz to 100 kHz, demonstrating a sound-pressure-equivalent noise spectral density down to 12 μPa/Hz(1/2), a flatband wider than 10 kHz, and very low distortion.
View details for DOI 10.1121/1.3543949
Slow Light in Fiber Bragg Gratings Conference on Advances in Slow and Fast Light IV Wen, H., Skolianos, G., Fan, S., Digonnet, M. SPIE-INT SOC OPTICAL ENGINEERING. 2011
Tactical-grade interferometric fiber optic gyroscope driven with a narrow-linewidth laser 21st International Conference on Optical Fiber Sensors Lloyd, S. W., Digonnet, M. J., Fan, S. SPIE-INT SOC OPTICAL ENGINEERING. 2011
Near shot-noise-limited performance of an open-loop laser-driven interferometric fiber optic gyroscope 21st International Conference on Optical Fiber Sensors Lloyd, S. W., Digonnet, M. J., Fan, S. SPIE-INT SOC OPTICAL ENGINEERING. 2011
Fabry-Perot Fiber Sensors with Reproducible Displacement Sensitivities 16th International Conference on Optical MEMS and Nanophotonics (OMN) Akkaya, O. C., Kilic, O., Digonnet, M. J., Kino, G. S., Solgaard, O. IEEE. 2011: 191–192
Optimization of the splice loss between photonic-bandgap fibers and conventional single-mode fibers OPTICS LETTERS Aghaie, K. Z., Digonnet, M. J., Fan, S. 2010; 35 (12): 1938-1940
To understand the loss limitations of a splice between a hollow-core fiber and a conventional fiber, we use a numerical model to calculate the expected coupling loss between the NKT Photonics' HC-1550-02 fiber and a single-mode fiber (SMF) of arbitrary step-index profile. When the SMF parameters are optimized, the splice loss is predicted to be as low as approximately 0.6 dB. This minimum is believed to be largely due to mode-shape mismatch. These predictions are confirmed experimentally by optimizing the splice loss between this photonic-bandgap fiber and five SMFs with different mode-field diameters (MFDs) and V numbers. With the SMF-28 fiber, the measured loss is 1.3 dB, in excellent agreement with theory. Using a SMF with parameters close to the optimum values (MFD=7.2 microm and V=2.16), this loss was reduced to a new record value of 0.79 dB.
Birefringence Analysis of Photonic-Bandgap Fibers Using the Hexagonal Yee's Cell IEEE JOURNAL OF QUANTUM ELECTRONICS Aghaie, K. Z., Fan, S., Digonnet, M. J. 2010; 46 (6): 920-930
View details for DOI 10.1109/JQE.2010.2040369
Measurement of reduced backscattering noise in laser-driven fiber optic gyroscopes OPTICS LETTERS Lloyd, S. W., Dangui, V., Digonnet, M. J., Fan, S., Kino, G. S. 2010; 35 (2): 121-123
We report what we believe to be the first demonstration of a laser-driven fiber optic gyroscope (FOG) built with an air-core fiber. Its phase noise is measured to be 130 murad/ radicalHz. When the sensing fiber is replaced with a conventional fiber, this figure drops to 12 murad/ radicalHz. Comparison between these values suggests that the air-core fiber gyro is most likely not limited solely by backscattering noise but by reflections at the solid-core/air-core interface. By minimizing additional noise sources and reducing the air-core fiber loss to its theoretical limit (approximately 0.1 dB/km), we predict that the backscattering noise of the laser-driven air-core FOG will drop below the level of current FOGs. Compared with commercial FOGs, this FOG will exhibit a lower noise, improved thermal and mean-wavelength stability, and reduced magnetic-field sensitivity.
Coupled resonator gyroscopes: what works and what does not Conference on Advances in Slow and Fast Light III Terrel, M. A., Digonnet, M. J., Fan, S. SPIE-INT SOC OPTICAL ENGINEERING. 2010
High-Sensitivity Thermally Stable Acoustic Fiber Sensor 2010 IEEE Sensors Conference Akkaya, O. C., Kilic, O., Digonnet, M. J., Kino, G. S., Solgaard, O. IEEE. 2010: 1148–1151
Asymmetrical Spectral Response in Fiber Fabry-Perot Interferometers (vol 27, pg 5648, 2009) JOURNAL OF LIGHTWAVE TECHNOLOGY Kilic, O., Digonnet, M. J., Kino, G. S., Solgaard, O. 2010; 28 (1): 188-188
Asymmetrical Spectral Response in Fiber Fabry-Perot Interferometers JOURNAL OF LIGHTWAVE TECHNOLOGY Kilic, O., Digonnet, M. J., Kino, G. S., Solgaard, O. 2009; 27 (24): 5648-5656
Ring-coupled Mach-Zehnder interferometer optimized for sensing APPLIED OPTICS Terrel, M., Digonnet, M. J., Fan, S. 2009; 48 (26): 4874-4879
We demonstrate numerically that the theoretical maximum sensitivity of a ring-coupled Mach-Zehnder interferometer (MZI) optimized as a sensor is about 30% greater than the optimized sensitivity of a conventional single-bus ring sensor with an identical ring perimeter and loss. The ring-coupled MZI sensor also achieves its greater sensitivity with a 25% lower circulating power, which is useful for the suppression of undesirable nonlinear effects.
Performance comparison of slow-light coupled-resonator optical gyroscopes LASER & PHOTONICS REVIEWS Terrel, M., Digonnet, M. J., Fan, S. 2009; 3 (5): 452-465
View details for DOI 10.1002/lpor.200810052
Modeling of the Propagation Loss and Backscattering in Air-Core Photonic-Bandgap Fibers JOURNAL OF LIGHTWAVE TECHNOLOGY Dangui, V., Digonnet, M. J., Kino, G. S. 2009; 27 (17): 3783-3789
Classification of the Core Modes of Hollow-Core Photonic-Bandgap Fibers IEEE JOURNAL OF QUANTUM ELECTRONICS Aghaie, K. Z., Dangui, V., Digonnet, M. J., Fan, S., Kino, G. S. 2009; 45 (9): 1192-1200
Measurements of the Birefringence and Verdet Constant in an Air-Core Fiber JOURNAL OF LIGHTWAVE TECHNOLOGY Wen, H., Terrel, M. A., Kim, H. K., Digonnet, M. J., Fan, S. 2009; 27 (15): 3194-3201
Laser-driven photonic-bandgap fiber optic gyroscope with negligible Kerr-induced drift OPTICS LETTERS Dangui, V., Digonnet, M. J., Kino, G. S. 2009; 34 (7): 875-877
We predict theoretically and confirm experimentally that the Kerr-induced phase drift of a fiber optic gyroscope (FOG) operated with a laser instead of a broadband source is virtually eliminated when the sensing coil is made of an air-core photonic-bandgap fiber. This is the first demonstration of a laser-driven FOG with a Kerr-induced drift low enough to meet the inertial navigation requirement for a 10-h transcontinental flight.
Performance Limitation of a Coupled Resonant Optical Waveguide Gyroscope JOURNAL OF LIGHTWAVE TECHNOLOGY Terrel, M. A., Digonnet, M. J., Fan, S. 2009; 27 (1-4): 47-54
View details for DOI 10.1109/JLT.2008.927753
High-Power Yb3+-Doped Phosphate Fiber Amplifier IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS Lee, Y., Digonnet, M. J., Sinha, S., Urbanek, K. E., Byer, R. L., Jiang, S. 2009; 15 (1): 93-102
View details for DOI 10.1109/JSTQE.2008.2010263
Coupled resonator optical waveguide sensors: sensitivity and the role of slow light Conference on Fiber Optic Sensors and Applications VI Terrel, M. A., Digonnet, M. J., Fan, S. SPIE-INT SOC OPTICAL ENGINEERING. 2009
Room-Temperature Stable Generation of 19 Watts of Single-Frequency 532-nm Radiation in a Periodically Poled Lithium Tantalate Crystal JOURNAL OF LIGHTWAVE TECHNOLOGY Sinha, S., Hum, D. S., Urbanek, K. E., Lee, Y., Digonnet, M. J., Fejer, M. M., Byer, R. L. 2008; 26 (21-24): 3866-3871
Controlling uncoupled resonances in photonic crystals through breaking the mirror symmetry OPTICS EXPRESS Kilic, O., Digonnet, M., Kino, G., Solgaard, O. 2008; 16 (17): 13090-13103
We show that modes in a photonic crystal slab that are uncoupled to outside radiation in a symmetric structure can be excited by breaking the mirror symmetry through introducing a protrusion on the side of the photonic crystal holes. We show that coupling to these resonances can be controlled by the strength of this asymmetry, and that it is also possible to choose among modes to couple to, through the shape of the asymmetry introduced. We provide simple theoretical arguments that explain the effect, and present eigenmode simulations and time-domain simulations. We confirm this predicted behavior with measurements on a photonic crystal with a broken mirror symmetry that exhibits an additional sharp resonant feature with a linewidth of 0.5 nm, in agreement with both calculated and simulated predictions.
Self-phase-locked degenerate femtosecond optical parametric oscillator OPTICS LETTERS Wong, S. T., Plettner, T., Vodopyanov, K. L., Urbanek, K., Digonnet, M., Byer, R. L. 2008; 33 (16): 1896-1898
We demonstrated a stable degenerate synchronously pumped femtosecond optical parametric oscillator (SPOPO) as a divide-by-2 subharmonic generator. The SPOPO exhibited passive all-optical self-phase-locking between the pump and signal/idler and thus required no external electronic feedback to produce the phase-locked subharmonic. We employed a type I phase-matched, 1-mm-long, periodically poled MgO:LiNbO3 crystal as the nonlinear gain element and an 80 MHz mode-locked Ti:sapphire laser with 180 fs pulses tuned at 775 nm as the pump. The SPOPO generated transform-limited 70 fs phase-locked output pulses centered at 1550 nm. The self-phase-locking operation was confirmed by separate beat-note measurement techniques with respect to the pump laser and with respect to an external cw laser.
Measurement of high photodarkening resistance in heavily Yb3+-doped phosphate fibres ELECTRONICS LETTERS Lee, Y. W., Sinha, S., Digonnet, M. J., Byer, R. L., Jiang, S. 2008; 44 (1): 14-15
View details for DOI 10.1049/el:20082698
10-Watt, Single-mode, Single-frequency, 1.03 mu m Yb3+-doped Phosphate Fiber Amplifier Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science Conference (CLEO/QELS 2008) Lee, Y. W., Sinha, S., Digonnet, M. J., Byer, R. L., Jiang, S. IEEE. 2008: 230–231
Laser-driven fiber optic gyroscope with reduced noise 19th International Conference on Optical Fibre Sensors Dangui, V., Digonnet, M. J., Kino, G. S. SPIE-INT SOC OPTICAL ENGINEERING. 2008
Photonic-crystal-diaphragm-based fiber-tip hydrophone optimized for ocean acoustics 19th International Conference on Optical Fibre Sensors Kilic, O., Digonnet, M., Kino, G., Solgaard, O. SPIE-INT SOC OPTICAL ENGINEERING. 2008
External fibre Fabry-Perot acoustic sensor based on a photonic-crystal mirror 18th International Conference on Optical Fibre Sensors Kilic, O., Digonnet, M., Kino, G., Solgaard, O. IOP PUBLISHING LTD. 2007: 3049–54
View details for DOI 10.1088/0957-0233/18/10/S01
Sensitivity and stability of an air-core fibre-optic gyroscope 18th International Conference on Optical Fibre Sensors Digonnet, M., Blin, S., Kim, H. K., Dangui, V., Kino, G. IOP PUBLISHING LTD. 2007: 3089–97
Noise analysis of an air-core fiber optic gyroscope IEEE PHOTONICS TECHNOLOGY LETTERS Blin, S., Digonnet, M. J., Kino, G. S. 2007; 19 (17-20): 1520-1522
View details for DOI 10.1109/LPT.2007.903878
Linearly polarized, 3.35 W narrow-linewidth, 1150 nm fiber master oscillator power amplifier for frequency doubling to the yellow OPTICS LETTERS Sinha, S., Urbanek, K. E., Hum, D. S., Digonnet, M. J., Fejer, M. M., Byer, R. L. 2007; 32 (11): 1530-1532
A high-power linearly polarized Yb-doped silica fiber master oscillator power amplifier at 1150 nm is reported. It produced 3.35 W cw and 2.33 W of average power in 1 micros pulses at a 100 kHz repetition rate, both with 8 pm linewidth. This is the first report, to the best of our knowledge, of a high-power Yb-doped fiber amplifier at a wavelength longer than 1135 nm. The pulsed output was frequency doubled in a bulk periodically poled near-stoichiometric LiTaO(3) chip to generate 976 mW of average power at 575 nm with an overall system optical-to-optical efficiency of 9.8% with respect to launched pump power.
Polarization controller for hollow-core fiber OPTICS LETTERS Terrel, M., Digonnet, M. J., Fan, S. 2007; 32 (11): 1524-1526
We demonstrate a universal polarization controller for hollow-core fibers, a simple device consisting of three twisted fiber sections that makes use of the inherent birefringence of the air-core fiber. The device 5% bandwidth at 1550 nm is calculated from measured data to be approximately 13 nm.
Determination of the mode reflection coefficient in air-core photonic bandgap fibers OPTICS EXPRESS Dangui, V., Digonnet, M. J., Kino, G. S. 2007; 15 (9): 5342-5359
Using an eigenmode decomposition technique, we numerically determine the backreflection coefficient of the modes of air-core photonic bandgap fibers for flat terminations. This coefficient is found to be very small for the fundamental air-guided mode, of the order of 10(-5) to 10(-6), in contrast with the surface and bulk modes, which exhibit significantly higher reflections, by about three to four orders of magnitude. For the Crystal Fibre HC-1550-2 fiber, we find a reflection coefficient of 1.9x10(-6) for an air termination, and approximately 3.3% for a silica termination. We also find that the Fresnel approximation is ill suited for the determination of the modal reflection coefficient, and instead propose a more accurate new formula based on an averaged modal index.
Observation of mode coupling in bitapered air-core photonic bandgap fibers OPTICS COMMUNICATIONS Ozcan, A., Tewary, A., Digonnet, M. J., Kino, G. S. 2007; 271 (2): 391-395
View details for DOI 10.1016/j.optcom.2006.10.039
Reduced thermal sensitivity of a fiber-optic gyroscope using an air-core photonic-bandgap fiber JOURNAL OF LIGHTWAVE TECHNOLOGY Blin, S., Kim, H. K., Digonnet, M. J., Kino, G. S. 2007; 25 (3): 861-865
Quasi-phase-matched grating characterization using minimum-phase functions OPTICS COMMUNICATIONS Ozcan, A., Digonnet, M. J., Kino, G. S. 2007; 269 (1): 199-205
Measurement of the stimulated Brillouin scattering gain coefficient of a phosphate fiber Conference on Optical Components and Materials IV Lee, Y. W., Urbanek, K. E., Digonnet, M. J., Byer, R. L., Jiang, S. SPIE-INT SOC OPTICAL ENGINEERING. 2007
2.6-watt average-power mode-locked ceramic Nd : YAG laser Conference on Optical Components and Materials IV Wisdom, J. A., Hum, D. S., Digonnet, M. J., Ikesue, A., Fejer, M. M., Byer, R. L. SPIE-INT SOC OPTICAL ENGINEERING. 2007
20 W single-mode Yb3+-doped phosphate fiber laser OPTICS LETTERS Lee, Y. W., Sinha, S., Digonnet, M. J., Byer, R. L., Jiang, S. 2006; 31 (22): 3255-3257
We report the demonstration of the first, to our knowledge, cladding-pumped continuous-wave Yb(3+)-doped phosphate-glass fiber laser. Phosphate hosts are of interest because they can be much more heavily doped than silica, and because of the possibility that they may have a higher photodarkening threshold. In an 84.6 cm double-clad fiber doped with 12 wt. % of Yb(2)O(3) and laser-diode pumped at 940 nm, nearly 20 W of single-mode 1.07 microm output power was generated with 60.2 W of absorbed pump power. The measured dependence of the output power on pump power is in excellent agreement with simulations.
Silicon-nanocrystal-coated silica microsphere thermooptical switch IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS Tewary, A., Digonnet, M. J., Sung, J., Shin, J. H., Brongersma, M. L. 2006; 12 (6): 1476-1479
View details for DOI 10.1109/JSTQE.2006.885389
Air-core photonic-bandgap fiber-optic gyroscope JOURNAL OF LIGHTWAVE TECHNOLOGY Kim, H. K., Digonnet, M. J., Kino, G. S. 2006; 24 (8): 3169-3174
Pickup suppression in Sagnac-based fiber-optic acoustic sensor array JOURNAL OF LIGHTWAVE TECHNOLOGY Blin, S., Bishop, M., Parameswaran, K., Digonnet, M. J., Kino, G. S. 2006; 24 (7): 2889-2897
Modeling and measurement of the acoustic lead sensitivity in Sagnac fiber sensor arrays JOURNAL OF LIGHTWAVE TECHNOLOGY Digonnet, M. J., Bishop, M., Kino, G. S. 2006; 24 (7): 2877-2888
Minimum-phase-function-based processing in frequency-domain optical coherence tomography systems JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION Ozcan, A., Digonnet, M. J., Kino, G. S. 2006; 23 (7): 1669-1677
We present a simple processing technique that uses the concept of minimum-phase functions to improve frequency-domain optical coherence tomography systems. Our approach removes the autocorrelation noise and therefore increases both the accessible depth range and the recovery accuracy. To our knowledge, this is the first time that the concept of minimum-phase functions has been applied to improve optical coherence tomography.
Bending-induced birefringence of optical fiber cladding modes JOURNAL OF LIGHTWAVE TECHNOLOGY Block, U. L., Digonnet, M. J., Fejer, M. M., Dangui, V. 2006; 24 (6): 2336-2339
A fast and accurate numerical tool to model the modal properties of photonic-bandgap fibers OPTICS EXPRESS Dangui, V., Digonnet, M. J., Kino, G. S. 2006; 14 (7): 2979-2993
We describe a finite-difference numerical method that allows us to simulate the modes of air-core photonic-bandgap fibers (PBF) of any geometry in minutes on a standard PC. The modes' effective indices and fields are found by solving a vectorial transverse magnetic-field equation in a matrix form, which can be done quickly because this matrix is sparse and because we reduce its bandwidth by rearranging its elements. The Stanford Photonic-Bandgap Fiber code, which is based on this method, takes about 4 minutes to model 20 modes of a typical PBF on a PC. Other advantages include easy coding, faithful modeling of the abrupt discontinuities in the index profile, high accuracy, and applicability to waveguides of arbitrarily complex profile.
A new iterative technique to characterize and design transmission fiber Bragg gratings JOURNAL OF LIGHTWAVE TECHNOLOGY Ozcan, A., Digonnet, M. J., Lablonde, L., Pureur, D., Kino, G. S. 2006; 24 (4): 1913-1921
Characterization of fiber Bragg gratings using spectral interferometry based on minimum-phase functions JOURNAL OF LIGHTWAVE TECHNOLOGY Ozcan, A., Digonnet, M. J., Kino, G. S. 2006; 24 (4): 1739-1757
Efficient yellow-light generation by frequency doubling a narrow-linewidth 1150 nm ytterbium fiber oscillator OPTICS LETTERS Sinha, S., Langrock, C., Digonnet, M. J., Fejer, M. M., Byer, R. L. 2006; 31 (3): 347-349
A linearly polarized, narrow-linewidth, diode-pumped, Yb-doped silica-fiber oscillator operating at 1150 nm was frequency doubled to produce 40 mW of 575 nm radiation. The oscillator generated 89 mW of cw linearly polarized output power and was tunable over 0.80 nm. The laser output was coupled to a periodically poled LiNbO3 waveguide that converted 67% of the coupled power to the yellow. The system was fully integrated, with no free-space optics, and had an overall optical-to-optical efficiency of 7.0% with respect to the incident diode-laser pump power.
Origin of apparent resonance mode splitting in bent long-period fiber gratings JOURNAL OF LIGHTWAVE TECHNOLOGY Block, U. L., Dangui, V., Digonnet, M. J., Fejer, M. M. 2006; 24 (2): 1027-1034
Characterization of fiber Bragg gratings using spectral interferometry based on minimum-phase functions Conference on Optical Components and Materials III Ozcan, A., Digonnet, M. J., Kino, G. S. SPIE-INT SOC OPTICAL ENGINEERING. 2006
Frequency-domain optical coherence tomography based on minimum-phase functions Conference on Coherence Domain Optical Methods and Optical Coherence Tomography in Biomedicine X Ozcan, A., Digonnet, M. J., Kino, G. S. SPIE-INT SOC OPTICAL ENGINEERING. 2006
Silicon-nanocrystal-coated silica microsphere then-nooptical switch Conference on Silicon Photonics Tewary, A., Digonnet, M. J., Brongersma, M. L. SPIE-INT SOC OPTICAL ENGINEERING. 2006
Measurement of the nonlinear coefficient profile of quasi-phase-matched gratings using iterative error-reduction algorithms Conference on Nonlinear Frequency Generation and Conversion - Materials, Devices and Applications V Ozcan, A., Digonnet, M. J., Kino, G. S. SPIE-INT SOC OPTICAL ENGINEERING. 2006
Transmission properties of tapered air-core photonic bandgap fibers Conference on Active and Passive Optical Components for Communication VI Ozcan, A., Tewary, A., Digonnet, M. J., Kino, G. S. SPIE-INT SOC OPTICAL ENGINEERING. 2006
A polarization controller for air-core photonic-bandgap fiber Conference on Optical Fiber Communications/National Fiber Optic Engineers Conference Terrel, M., Digonnet, M., Fan, S. OPTICAL SOC AMERICA. 2006: 681–683
Understanding air-core photonic-bandgap fibers: Analogy to conventional fibers JOURNAL OF LIGHTWAVE TECHNOLOGY Digonnet, M. J., Kim, H. K., Kino, G. S., Fan, S. H. 2005; 23 (12): 4169-4177
Phase sensitivity to temperature of the fundamental mode in air-guiding photonic-bandgap fibers OPTICS EXPRESS Dangui, V., Kim, H. K., Digonnet, M. J., Kino, G. S. 2005; 13 (18): 6669-6684
Because in an air-core photonic-bandgap fiber the fundamental mode travels mostly in air, as opposed to silica in a conventional fiber, the phase of this mode is expected to have a much lower dependence on temperature than in a conventional fiber. We confirm with interferometric measurements in air-core fibers from two manufacturers that their thermal phase sensitivity is indeed ~3 to ~6 times smaller than in an SMF28 fiber, in agreement with an advanced theoretical model. With straightforward fiber design changes (thinner jacket and thicker outer cladding), this sensitivity could be further reduced down to ~11 times that of a standard fiber. This feature is anticipated to have important benefits in fiber optic systems and sensors, especially in the fiber optic gyroscope where it translates into a lower Shupe effect and thus a greater long-term stability.
Ultra-short pulse characterization using a reference laser pulse Conference on Laser Resonators and Beam Control VIII Ozcan, A., Digonnet, M. J., Kino, G. S. SPIE-INT SOC OPTICAL ENGINEERING. 2005: 140–150
Thermally poled germanosilicate films with high secondorder nonlinearity Conference on Lasers and Electro-Optics (CLEO) Ozcan, A., Digonnet, M. J., Kino, G. S., Ay, F., Aydinli, A. OPTICAL SOC AMERICA. 2005: 2097–2099
Excitation of non-degenerate resonances through breaking of mirror symmetry in photonic crystal slabs Conference on Lasers and Electro-Optics (CLEO) Kilic, O., Kim, S., Digonnet, M., Kino, G., Solgaard, O. OPTICAL SOC AMERICA. 2005: 828–830
Dependence of the induced optical second-order nonlinearity profile of poled silica samples on poling conditions Conference on Optical Components and Materials II Ozcan, A., Digonnet, M. J., Kino, G. S. SPIE-INT SOC OPTICAL ENGINEERING. 2005: 187–197
Detailed analysis of inverse Fourier transform techniques to uniquely infer second-order nonlinearity profile of thin films JOURNAL OF APPLIED PHYSICS Ozcan, A., Digonnet, M. J., Kino, G. S. 2005; 97 (1)
SIMBA: A new technique for ultrashort pulse characterization Digest of the LEOS Summer Topical Meeting Ozcan, A., Digonnet, M. J., Kino, G. S. IEEE. 2005: 215–216
Fiber-optic gyroscope using an air-core photonic-bandgap fiber 17th International Conference on Optical Fibre Sensors Kim, H. K., Dangui, V., Digonnet, M., Kino, G. SPIE-INT SOC OPTICAL ENGINEERING. 2005: 198–201
Ultrabroadband single-mode long-period fiber gratings using high-order cladding modes JOURNAL OF APPLIED PHYSICS Dangui, V., Digonnet, M. J., Kino, G. S. 2004; 96 (11): 5987-5991
Characterization of thermally poled germanosilicate thin films OPTICS EXPRESS Ozcan, A., Digonnet, M. J., Kino, G. S., Ay, F., Aydinli, A. 2004; 12 (20): 4698-4708
We report measurements of the nonlinearity profile of thermally poled low-loss germanosilicate films deposited on fused-silica substrates by PECVD, of interest as potential electro-optic devices. The profiles of films grown and poled under various conditions all exhibit a sharp peak ~0.5 microm beneath the anode surface, followed by a weaker pedestal of approximately constant amplitude down to a depth of 13-16 microm, without the sign reversal typical of poled undoped fused silica. These features suggest that during poling, the films significantly slow down the injection of positive ions into the structure. After local optimization, we demonstrate a record peak nonlinear coefficient of ~1.6 pm/V, approximately twice as strong as the highest reliable value reported in thermally poled fused silica glass, a significant improvement that was qualitatively expected from the presence of Ge.
Group delay recovery using iterative processing of amplitude of transmission spectra of fibre Bragg gratings ELECTRONICS LETTERS Ozcan, A., Digonnet, M. J., Kino, G. S. 2004; 40 (18): 1104-1106
Simulations of the effect of the core ring on surface and air-core modes in photonic bandgap fibers OPTICS EXPRESS Kim, H. K., Digonnet, M. J., Kino, G. S., Shin, J. W., Fan, S. H. 2004; 12 (15): 3436-3442
We show through computer simulations that the thin silica ring that surrounds the air core of a photonic-bandgap fiber introduces surface modes. The intensity profile and dispersion of these modes indicate that they are the modes of the waveguide formed by the ring surrounded by air on one side and the photonic crystal cladding on the other. The ring also induces small perturbations of the fundamental core mode. Coupling to those surface modes, which have propagation constants close to that of the core mode, are likely to induce substantial loss to the core mode. By reducing the thickness of the ring and/or by suitably selecting its radius the propagation constants of the surface modes can be moved farther from that of the core mode and the loss reduced.
Iterative processing of second-order optical nonlinearity depth profiles OPTICS EXPRESS Ozcan, A., Digonnet, M. J., Kino, G. S. 2004; 12 (15): 3367-3376
We show through numerical simulations and experimental data that a fast and simple iterative loop known as the Fienup algorithm can be used to process the measured Maker-fringe curve of a nonlinear sample to retrieve the sample's nonlinearity profile. This algorithm is extremely accurate for any profile that exhibits one or two dominant peaks, which covers a wide range of practical profiles, including any nonlinear film of crystalline or organic material (rectangular profiles) and poled silica, for which an excellent experimental demonstration is provided. This algorithm can also be applied to improve the accuracy of the nonlinearity profile obtained by an inverse Fourier transform technique.
Simple geometric criterion to predict the existence of surface modes in air-core photonic-bandgap fibers OPTICS EXPRESS Digonnet, M. J., Kim, H. K., Shin, J., Fan, S. H., Kino, G. S. 2004; 12 (9): 1864-1872
We propose a simple geometric criterion based on the size of the core relative to the photonic crystal to quickly determine whether an air-core photonic-bandgap fiber with a given geometry supports surface modes. Comparison to computer simulations show that when applied to fibers with a triangular-pattern cladding and a circular air core, this criterion accurately predicts the existence of a finite number of discrete ranges of core radii that support no surface modes. This valuable tool obviates the need for time-consuming and costly simulations, and it can be easily applied to fibers with an arbitrary photonic-crystal structure and core profile.
Designing air-core photonic-bandgap fibers free of surface modes IEEE JOURNAL OF QUANTUM ELECTRONICS Kim, H. K., Shin, J., Fan, S. H., Digonnet, M. J., Kino, G. S. 2004; 40 (5): 551-556
View details for DOI 10.1109/JQE.2004.826429
Simplified inverse Fourier transform technique to measure optical nonlinearity profiles using reference sample ELECTRONICS LETTERS Ozcan, A., Digonnet, M. J., Kino, G. S. 2004; 40 (9): 551-552
Improved technique to determine second-order optical nonlinearity profiles using two different samples APPLIED PHYSICS LETTERS Ozcan, A., Digonnet, M. J., Kino, G. S. 2004; 84 (5): 681-683
Ceramic lasers: Ready for action PHOTONICS SPECTRA Wisdom, J., Digonnet, M., Byer, R. L. 2004; 38 (2): 50-?
Acoustic fiber sensor arrays 2nd European Workshop on Optical Fibre Sensors Digonnet, M. J., Vakoc, B. J., Hodgson, C. W., Kino, G. S. SPIE-INT SOC OPTICAL ENGINEERING. 2004: 39–50
Comparison of three inverse Fourier transform techniques to determine the second-order optical nonlinearity profile of thin films Conference Optics and Photonic Integrated Circuits Ozcan, A., Digonnet, M. J., Kino, G. S. SPIE-INT SOC OPTICAL ENGINEERING. 2004: 304–310
Cylinder-assisted Maker-fringe technique to probe second-order optical nonlinearity profiles Conference on Optical Components and Materials Ozcan, A., Digonnet, M. J., Kino, G. S. SPIE-INT SOC OPTICAL ENGINEERING. 2004: 109–114
Demonstration of a folded Sagnac sensor array immune to polarization-induced signal fading APPLIED OPTICS Vakoc, B. J., Digonnet, M. J., Kino, G. S. 2003; 42 (36): 7132-7136
We demonstrate a new folded Sagnac sensor array design that combines a Faraday rotator mirror and a polarization beam splitter to eliminate the optical noise pulses otherwise generated in a folded Sagnac sensor array. A depolarization scheme compatible with this configuration is also proposed and demonstrated experimentally. It is shown that this new configuration passively eliminates polarization-induced signal fading on every sensor in the array. The minimum detectable phase was measured to be approximately 1.1 microrad/square root of Hz, in agreement with theory.
Cylinder-assisted maker-fringe technique ELECTRONICS LETTERS Ozcan, A., Digonnet, M. J., Kino, G. S. 2003; 39 (25): 1834-1836
Er-doped superfluorescent fiber source with a +/- 0.5-ppm long-term mean-wavelength stability JOURNAL OF LIGHTWAVE TECHNOLOGY Park, H. G., Digonnet, M., Kino, G. 2003; 21 (12): 3427-3433
Inverse Fourier transform technique to determine second-order optical nonlinearity spatial profiles (vol 82, pg 1362, 2003) APPLIED PHYSICS LETTERS Ozcan, A., Digonnet, M. J., Kino, G. S. 2003; 83 (8): 1679-1679
Inverse Fourier transform technique to determine second-order optical nonlinearity spatial profiles APPLIED PHYSICS LETTERS Ozcan, A., Digonnet, M. J., Kino, G. S. 2003; 82 (9): 1362-1364
Fundamental limitations of the McCumber relation applied to Er-doped silica and other amorphous-host lasers IEEE JOURNAL OF QUANTUM ELECTRONICS Digonnet, M. J., Murphy-Chutorian, E., Falquier, D. G. 2002; 38 (12): 1629-1637
Polarization-independent mechanically induced long-period fiber gratings Conference on Optical Devices for Fiber Communication III Block, U. L., Ozcan, A., Digonnet, M. J., Fejer, M. M. SPIE-INT SOC OPTICAL ENGINEERING. 2002: 72–76
Passive WDM channel power equalization with cascaded nonlinear amplifying loop mirrors Conference on Optical Devices for Fiber Communication III Block, U. L., Vakoc, B. J., Digonnet, M. J., Fejer, M. M. SPIE-INT SOC OPTICAL ENGINEERING. 2002: 52–57
Feature section on fiber lasers and amplifiers IEEE JOURNAL OF QUANTUM ELECTRONICS Digonnet, M. J. 2001; 37 (9): 1109-1109
Measurement of the dc Kerr and electrostrictive phase modulation in silica JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS Liu, A. C., Digonnet, M. J., Kino, G. S. 2001; 18 (2): 187-194
Measurement of the electrostrictive constants of silica and their impact on poled silica devices Conference on Optical Devices for Fiber Communication II Liu, A. C., Digonnet, M. J., Kino, G. S. SPIE-INT SOCIETY OPTICAL ENGINEERING. 2001: 119–128
A depolarized Er-doped superfluorescent fiber source with improved long-term polarization stability IEEE PHOTONICS TECHNOLOGY LETTERS Falquier, D. G., Digonnet, M. J., Shaw, H. J. 2001; 13 (1): 25-27
A polarization-based folded Sagnac fiber-optic sensor array for acoustic waves Conference on Fiber Optic Sensor Technology and Applications Kino, G. S., Vakoc, B., Digonnet, M. J. SPIE-INT SOC OPTICAL ENGINEERING. 2001: 336–345
A polarization-stable Er-doped superfluorescent fiber source including a Faraday rotator mirror IEEE PHOTONICS TECHNOLOGY LETTERS Falquier, D. G., Digonnet, M. J., Shaw, H. J. 2000; 12 (11): 1465-1467
A folded configuration of a fiber Sagnac-based sensor array OPTICAL FIBER TECHNOLOGY Vakoc, B. J., Digonnet, M. J., Kino, G. S. 2000; 6 (4): 388-399
Tunable mechanically induced long-period fiber gratings OPTICS LETTERS Savin, S., Digonnet, M. J., Kino, G. S., Shaw, H. J. 2000; 25 (10): 710-712
We report the experimental characterization of mechanically induced long-period fiber gratings (LPFG's) made by pressing a plate with periodic grooves against a short length of fiber. This filter, which is simple and inexpensive, exhibits transmission spectra and temperature stability similar to those of photoinduced LPFG's. It also offers the unique advantages of being tunable, erasable, and reconfigurable. Its polarization dependence also makes it useful as a polarizer, although it can also be eliminated with simple mechanical designs.
Improved nonlinear coefficient (0.7 pm/V) in silica thermally poled at high voltage and temperature ELECTRONICS LETTERS Liu, A. C., Digonnet, M. J., Kino, G. S., Knystautas, E. J. 2000; 36 (6): 555-556
Measurements of thermal effects in fibers doped with cobalt and vanadium JOURNAL OF LIGHTWAVE TECHNOLOGY Davis, M. K., Digonnet, M. J. 2000; 18 (2): 161-165
A novel fiber-optic sensor array based on the Sagnac interferometer JOURNAL OF LIGHTWAVE TECHNOLOGY Vakoc, B. J., Digonnet, M. J., Kino, G. S. 1999; 17 (11): 2316-2326
Nanosecond thermal fiber switch using a Sagnac interferometer IEEE PHOTONICS TECHNOLOGY LETTERS Davis, M. K., Digonnet, M. J. 1999; 11 (10): 1256-1258
A novel fiber optic sensor array based on the Sagnac interferometer SPIE Conference on Fiber Optic Sensor Technology and Applications Vakoc, B. J., Digonnet, M. J., Kino, G. S. SPIE-INT SOC OPTICAL ENGINEERING. 1999: 276–284
Improved polarization stability of the output mean wavelength in an Er-doped superfluorescent fiber source incorporating a Faraday rotator mirror Conference on Optical Devices for Fiber Communication Falquier, D. G., Digonnet, M. J., Shaw, H. J. SPIE-INT SOC OPTICAL ENGINEERING. 1999: 10–15
Demonstration of a folded configuration of a fiber Sagnac-based sensor array SPIE Conference on Fiber Optic Sensor Technology and Applications Vakoc, B. J., Digonnet, M. J., Kino, G. S. SPIE-INT SOC OPTICAL ENGINEERING. 1999: 538–542
Polarized superfluorescent fiber sources OPTICAL FIBER TECHNOLOGY Falquier, D. G., Wagener, J. L., Digonnet, M. J., Shaw, H. J. 1998; 4 (4): 453-470
Phase-sensitivity measurement of a 10-sensor array with erbium-doped fiber amplifier telemetry OPTICS LETTERS Vakoc, B. J., Hodgson, C. W., Digonnet, M. J., Kino, G. S., Shaw, H. J. 1998; 23 (16): 1313-1315
We report what are believed to be the first measurements of the phase sensitivity of a fiber sensor array using multiple low-gain remotely pumped amplifiers with an interferometric sensor inserted. The measured phase sensitivities for individual rungs average 5.7 microrad(rms)/ radicalHz and exhibit no dependence on rung number, in agreement with predictions.
Large-scale interferometric fiber sensor arrays incorporating multiple optical switches OPTICAL FIBER TECHNOLOGY Hodgson, C. W., Digonnet, M. J., Shaw, H. J. 1998; 4 (3): 316-327
Thermal effects in doped fibers JOURNAL OF LIGHTWAVE TECHNOLOGY Davis, M. K., Digonnet, M. J., PANTELL, R. H. 1998; 16 (6): 1013-1023
Experimental and theoretical analysis of the resonant nonlinearity in ytterbium-doped fiber JOURNAL OF LIGHTWAVE TECHNOLOGY Arkwright, J. W., Elango, P., Atkins, G. R., Whitbread, T., Digonnet, M. J. 1998; 16 (5): 798-806
Absolute measurement of the second-order nonlinearity profile in poled silica OPTICS LETTERS Pureur, D., Liu, A. C., Digonnet, M. J., Kino, G. S. 1998; 23 (8): 588-590
Measurement of the thin nonlinearity profile of poled silica by the Maker fringe technique has been impossible because of total internal reflection (TIR) at the back surface of the sample. We demonstrate that this limitation can be removed by placing a prism against each face of the sample, thus avoiding TIR. This novel technique allows, for the first time to our knowledge, the nonlinearity profile of a thin film to be inferred by the Maker fringe technique. Applied to a silica sample thermally poled under standard conditions (275 degrees C and 5.3 kV for 30 min), it suggests a Gaussian profile with a 1/e width of 8 mum and a maximum d(33) of 0.34 pm/V.
Optimization of large-scale fiber sensor arrays incorporating multiple optical amplifiers - Part II: Pump power JOURNAL OF LIGHTWAVE TECHNOLOGY Hodgson, C. W., Wagener, J. L., Digonnet, M. J., Shaw, H. J. 1998; 16 (2): 224-231
A mueller matrix formalism for modeling polarization effects in erbium-doped fiber JOURNAL OF LIGHTWAVE TECHNOLOGY Wagener, J. L., Falquier, D. G., Digonnet, M. J., Shaw, H. J. 1998; 16 (2): 200-206
Optimization of large-scale fiber sensor arrays incorporating multiple optical amplifiers - Part I: Signal-to-noise ratio JOURNAL OF LIGHTWAVE TECHNOLOGY Hodgson, C. W., Wagener, J. L., Digonnet, M. J., Shaw, H. J. 1998; 16 (2): 218-223
DC Kerr coefficient in silica: theory and experiment Conference on Doped Fiber Devices II Liu, A., Digonnet, M., Kino, G. SPIE - INT SOC OPTICAL ENGINEERING. 1998: 102–107
Polarization dependence of the mean wavelength of Er-doped superfluorescent fiber sources Conference on Doped Fiber Devices II Falquier, D. G., Digonnet, M. J., Kino, G. S., Shaw, H. J. SPIE - INT SOC OPTICAL ENGINEERING. 1998: 26–29
Advances in the measurement of the poled silica nonlinear profile Conference on Doped Fiber Devices II Liu, A. C., Digonnet, M. J., Kino, G. S. SPIE - INT SOC OPTICAL ENGINEERING. 1998: 115–119
Large-scale interferometric fiber sensor arrays with multiple optical amplifiers OPTICS LETTERS Hodgson, C. W., Digonnet, M. J., Shaw, H. J. 1997; 22 (21): 1651-1653
We report what we believe to be the first laboratory prototype of a fiber sensor array using multiple low-gain (5dB) remotely pumped amplifiers in a 10-rung ladder structure. Incorporating amplifiers improves the system noise figure to less than 20dB, compared with 32dB in an optimized passive array of the same size. Scalability to more than 300sensors per fiber pair while a high dynamic range (1microrad/ sensitivity) is maintained is demonstrated.
View details for Web of Science ID A1997YE15500024
A high-stability fiber amplifier source for the fiber optic gyroscope JOURNAL OF LIGHTWAVE TECHNOLOGY Wagener, J. L., Digonnet, M. J., Shaw, H. J. 1997; 15 (9): 1689-1694
View details for Web of Science ID A1997XV75100009
Novel fiber sensor arrays using erbium-doped fiber amplifiers JOURNAL OF LIGHTWAVE TECHNOLOGY Wagener, J. L., Hodgson, C. W., Digonnet, M. J., Shaw, H. J. 1997; 15 (9): 1681-1688
Polarized superfluorescent fiber source OPTICS LETTERS Falquier, D. G., Wagener, J. L., Digonnet, M. J., Shaw, H. J. 1997; 22 (3): 160-162
We report the demonstration of a polarized superfluorescent fiber source (SFS) that increases the power output in the desired linearly polarized component by a factor of 1.76 over that of a standard, unpolarized SFS that uses the same pump power. This increase in efficiency is accomplished by insertion of a low-loss polarizer at an optimum point in the erbium-doped fiber of a standard SFS.
View details for Web of Science ID A1997WE37600008
Experimental evidence for strong UV transition contribution in the resonant nonlinearity of doped fibers JOURNAL OF LIGHTWAVE TECHNOLOGY Digonnet, M. J., Sadowski, R. W., Shaw, H. J., PANTELL, R. H. 1997; 15 (2): 299-303
View details for Web of Science ID A1997WH67600016
Resonantly enhanced nonlinearity in doped fibers for low-power all-optical switching: A review OPTICAL FIBER TECHNOLOGY Digonnet, M. J., Sadowski, R. W., Shaw, H. J., PANTELL, R. H. 1997; 3 (1): 44-64
View details for Web of Science ID A1997XP55600006
Basis for a polarized superfluorescent fiber source with increased efficiency OPTICS LETTERS Falquier, D. G., Wagener, J. L., Digonnet, M. J., Shaw, H. J. 1996; 21 (23): 1900-1902
We propose to produce a superfluorescent fiber source (SFS) with a linearly polarized output by inserting a discrete polarizer near the middle of a polarization-maintaining Er-doped fiber. We show that with a relatively low-loss polarizer (<0.5 dB) the output power of the polarized SFS is predicted to approach that of a standard, unpolarized SFS, i.e., the power of the desired polarization mode is nearly doubled. The efficiency of this source depends weakly on the polarizer location and extinction ratio, although it depends strongly on its insertion loss.
View details for Web of Science ID A1996VV69000010
Switching power reduction using a pumped nonlinear directional coupler IEEE PHOTONICS TECHNOLOGY LETTERS Davis, M. K., Digonnet, M. J. 1996; 8 (10): 1328-1330
View details for Web of Science ID A1996VH22700016
All-optical switching using color centers in an irradiated phosphorus-doped fiber IEEE PHOTONICS TECHNOLOGY LETTERS Sadowski, R. W., Digonnet, M. J., PANTELL, R. H., Shaw, H. J., Simpson, J. R., Yan, M. 1996; 8 (7): 897-899
View details for Web of Science ID A1996UT30000017
Parametric analysis of semiconductor-doped classes for all-optical switching JOURNAL OF LIGHTWAVE TECHNOLOGY Mayweather, D., Digonnet, M. J., PANTELL, R. H. 1996; 14 (4): 601-610
View details for Web of Science ID A1996UE70000010
A DC Kerr measurement in a silica channel waveguide Conference on Doped Fiber Devices Liu, A. C., Digonnet, M. J., Kino, G. S. SPIE-INT SOC OPTICAL ENGINEERING. 1996: 209–218
View details for Web of Science ID A1996BG81Z00022
Highly efficient polarized Er-doped superfluorescent fiber source Conference on Doped Fiber Devices Falquier, D. G., Wagener, J. L., Digonnet, M. J., Shaw, H. J. SPIE-INT SOC OPTICAL ENGINEERING. 1996: 35–41
Contribution of UV transitions to the strong third-order nonlinearity of doped fibers Conference on Doped Fiber Devices Digonnet, M. J., Sadowski, R. W., Shaw, H. J., PANTELL, R. H. SPIE-INT SOC OPTICAL ENGINEERING. 1996: 183–188
Kramers-Kronig analysis of the absorption change in fiber gratings Conference on Doped Fiber Devices Digonnet, M. J. SPIE-INT SOC OPTICAL ENGINEERING. 1996: 109–120
CHARACTERIZATION OF CLUSTERS IN RARE-EARTH-DOPED FIBERS BY TRANSMISSION MEASUREMENTS JOURNAL OF LIGHTWAVE TECHNOLOGY Davis, M. K., Digonnet, M. J., PANTELL, R. H. 1995; 13 (2): 120-126
View details for Web of Science ID A1995QH36100003
ELECTROOPTIC PHASE MODULATION IN A SILICA CHANNEL WAVE-GUIDE OPTICS LETTERS Liu, A. C., Digonnet, M. J., Kino, G. S. 1994; 19 (7): 466-468
We report what is to our knowledge the first demonstration of electro-optic phase modulation in a fused-silica channel waveguide. The nonlinearity is induced through elevated temperature poling of an electron-beamirradiated waveguide. A phase shift of 32 mrad was measured at lambda = 633 nm for a device interaction length of 4.8 mm and an applied electric field of 7.3 V/microm.
View details for Web of Science ID A1994NC78800014
MODELING OF ION-PAIRS IN ERBIUM-DOPED FIBER AMPLIFIERS OPTICS LETTERS Wagener, J. L., WYSOCKI, P. F., Digonnet, M. J., Shaw, H. J. 1994; 19 (5): 347-349
The effects of Er-Er pairs on the characteristics of Er-doped fiber amplifiers are analyzed theoretically. Pairs are found to have little effect on the amplifier optimum length, signal saturation power, and noise figure (at constant gain) but to cause significant reduction in the gain, even at residual levels, quantitatively consistent with fiber laser measurements. A maximum tolerable fraction of paired ions near 8%, corresponding to approximately 400 mole parts in 10(6) Er(2)O(3), is predicted for near-optimum gain efficiency in Al-Ge silica fibers.
View details for Web of Science ID A1994MY67400013
A MODEL OF NONLINEAR ALL-OPTICAL SWITCHING IN DOPED FIBERS JOURNAL OF LIGHTWAVE TECHNOLOGY PANTELL, R. H., Digonnet, M. J. 1994; 12 (1): 149-156
View details for Web of Science ID A1994MX06500021
STATUS OF BROAD-BAND RARE-EARTH-DOPED FIBER SOURCES FOR FOG APPLICATIONS Conference on Fiber Optic and Laser Sensors XI Digonnet, M. J. SPIE - INT SOC OPTICAL ENGINEERING. 1994: 113–131
View details for Web of Science ID A1994BA45K00013
NOVEL TECHNIQUES TO CHARACTERIZE CLUSTERING IN ND-DOPED FIBERS Conference on Fiber Laser Sources and Amplifiers V Davis, M. K., Digonnet, M. J., Sadowski, R. W., PANTELL, R. H. SPIE - INT SOC OPTICAL ENGINEERING. 1994: 50–64
EFFECTS OF ER3+ PAIRS ON THE GAIN AND NOISE-FIGURE OF EDFAS Conference on Fiber Laser Sources and Amplifiers V Wagener, J. L., WYSOCKI, P. F., Digonnet, M. J., Shaw, H. J. SPIE - INT SOC OPTICAL ENGINEERING. 1994: 86–91
CHARACTERIZATION OF THE 2ND-ORDER NONLINEARITY IN POLED FUSED-SILICA Conference on Doped Fiber Devices and Systems Liu, A. C., Digonnet, M. J., Kino, G. S. SPIE - INT SOC OPTICAL ENGINEERING. 1994: 194–206
View details for Web of Science ID A1994BB55D00022
MEASUREMENTS AND MODELING OF THE OUTPUT POLARIZATION OF ER-DOPED FIBER LASERS Conference on Doped Fiber Devices and Systems FALQUIER, D., Lande, D., Wagener, J. L., Digonnet, M. J., Shaw, H. J. SPIE - INT SOC OPTICAL ENGINEERING. 1994: 24–40
EFFECT OF COMPOSITION ON CLUSTERING IN ER-DOPED FIBER LASERS Conference on Fiber Laser Sources and Amplifiers V Wagener, J. L., Digonnet, M. J., WYSOCKI, P. F., Shaw, H. J. SPIE - INT SOC OPTICAL ENGINEERING. 1994: 14–19
ALL-OPTICAL SWITCHING USING COLOR-CENTERS IN IRRADIATED SILICA FIBERS Conference on Doped Fiber Devices and Systems Sadowski, R. W., Digonnet, M. J., PANTELL, R. H., Shaw, H. J. SPIE - INT SOC OPTICAL ENGINEERING. 1994: 110–116
POWER AND LENGTH REQUIREMENTS FOR ALL-OPTICAL SWITCHING IN SEMICONDUCTOR-DOPED GLASS WAVE-GUIDES Conference on Doped Fiber Devices and Systems Mayweather, D. T., Digonnet, M. J., PANTELL, R. H., Shaw, H. J. SPIE - INT SOC OPTICAL ENGINEERING. 1994: 125–133
SUB-MICROSECOND ALL-OPTICAL SWITCHING IN NEODYMIUM-DOPED FIBER Conference on Fiber Laser Sources and Amplifiers V Sadowski, R. W., Digonnet, M. J., PANTELL, R. H., Shaw, H. J. SPIE - INT SOC OPTICAL ENGINEERING. 1994: 166–171
EFFECTS OF CONCENTRATION AND CLUSTERS IN ERBIUM-DOPED FIBER LASERS OPTICS LETTERS Wagener, J. L., WYSOCKI, P. F., Digonnet, M. J., Shaw, H. J., DiGiovanni, D. J. 1993; 18 (23): 2014-2016
View details for Web of Science ID A1993MJ09900008
ANALYSIS OF NONLINEAR-OPTICAL SWITCHING IN AN ERBIUM-DOPED FIBER JOURNAL OF LIGHTWAVE TECHNOLOGY PANTELL, R. H., Digonnet, M. J., Sadowski, R. W., Shaw, H. J. 1993; 11 (9): 1416-1424
View details for Web of Science ID A1993MG88600002
MICROSECOND OPTICAL OPTICAL SWITCHING IN A NEODYMIUM-DOPED 2-MODE FIBER OPTICS LETTERS Sadowski, R. W., Digonnet, M. J., PANTELL, R. H., Shaw, H. J. 1993; 18 (11): 927-929
View details for Web of Science ID A1993LD51700029
FABRICATION, CHARACTERIZATION AND INDEX PROFILE MODELING OF HIGH-DAMAGE RESISTANCE ZN-DIFFUSED WAVE-GUIDES IN CONGRUENT AND MGO - LITHIUM-NIOBATE JOURNAL OF LIGHTWAVE TECHNOLOGY Young, W. M., Fejer, M. M., Digonnet, M. J., Marshall, A. F., Feigelson, R. S. 1992; 10 (9): 1238-1246
View details for Web of Science ID A1992JQ25200010
LASER-DIODE-PUMPED NONLINEAR SWITCH IN ERBIUM-DOPED FIBER OPTICS LETTERS PANTELL, R. H., Sadowski, R. W., Digonnet, M. J., Shaw, H. J. 1992; 17 (14): 1026-1028
View details for Web of Science ID A1992JD25200021
PHOTOREFRACTIVE-DAMAGE-RESISTANT ZN-DIFFUSED WAVE-GUIDES IN MGO-LINBO3 OPTICS LETTERS Young, W. M., Feigelson, R. S., Fejer, M. M., Digonnet, M. J., Shaw, H. J. 1991; 16 (13): 995-997
Planar waveguides were fabricated by diffusing Zn into MgO:LiNbO(3) and LiNbO(3). Zn-diffused waveguides in MgO:LiNbO(3) guide both the ordinary and extraordinary polarization and have propagation losses at 633 nm in the range of 0.4-1.2 dB/cm. Single-beam-induced in-plane scattering due to photorefractive damage was not observed at 515 nm up to intensities of as much as 90 kW/cm(2).
View details for Web of Science ID A1991FU16000007
WAVELENGTH STABILITY OF A HIGH-OUTPUT, BROAD-BAND, ER-DOPED SUPERFLUORESCENT FIBER SOURCE PUMPED NEAR 980-NM OPTICS LETTERS WYSOCKI, P. F., Digonnet, M. J., Kim, B. Y. 1991; 16 (12): 961-963
We report the dependence of the mean wavelength of Er-doped superfluorescent fiber sources on temperature, pump wavelength, and pump power. In particular, we measure an intrinsic temperature coefficient of between -2 and +8 parts in 10(6) (ppm) per degree Celsius depending on pump wavelength, pump power, and fiber length. Additionally, we report a pump wavelength dependence that is symmetrical about the peak pump absorption wavelength (near 976 nm) and a decrease in mean wavelength with pump power with a slope of between 0 and -93 ppm/mW.
View details for Web of Science ID A1991FQ93900027
STABLE FIBER-SOURCE GYROSCOPES OPTICS LETTERS FESLER, K. A., Digonnet, M. J., Kim, B. Y., Shaw, H. J. 1990; 15 (22): 1321-1323
We describe two new configurations of fiber gyroscopes that use superfluorescent fiber laser sources. In the first configuration we introduce a backward-pumping technique that achieves an order-of-magnitude increase in the power that can be launched into the gyroscope without instabilities. In the second configuration we employ the optical gain of the superfluorescent fiber laser source to amplify the signal returned from the gyroscope, obtaining an additional three-orders-of-magnitude increase in the optical power incident upon the detector, with an implication for simplification of the electronics. In both configurations, source beat-noise-limited rotation sensitivity is achieved.
View details for Web of Science ID A1990EJ40800023
CLOSED-FORM EXPRESSIONS FOR THE GAIN IN 3-LEVEL AND 4-LEVEL LASER FIBERS IEEE JOURNAL OF QUANTUM ELECTRONICS Digonnet, M. J. 1990; 26 (10): 1788-1796
View details for Web of Science ID A1990EN85600014
NONINVASIVE SWITCHABLE ACOUSTOOPTIC TAPS FOR OPTICAL FIBER OPTICAL FIBER COMMUNICATIONS CONF ( OFC 90 ) Patterson, D. B., Howell, M. D., Digonnet, M., Kino, G. S., KHURIYAKUB, B. T. IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. 1990: 1304–12
View details for Web of Science ID A1990DU74200010
BROAD-SPECTRUM, WAVELENGTH-SWEPT, ERBIUM-DOPED FIBER LASER AT 1.55-MU-M OPTICS LETTERS WYSOCKI, P. F., Digonnet, M. J., Kim, B. Y. 1990; 15 (16): 879-881
We describe an argon-ion-laser-pumped erbium-doped fiber laser at 1.55 microm that incorporates low-rate frequency modulation of an intracavity acousto-optic modulator to provide repeated, continuous tuning of the output spectrum. The spectral width of this wavelength-swept fiber laser is as large as 20 nm with 9 mW of output power, even though erbium in silica has a mostly homogeneously broadened gain. The time-averaged visibility curve for a 14-nm-wide source indicates a short (160-microm) coherence length, which is of interest for fiber-optic gyroscopes that operate with long integration times and short-coherence-length sources.
View details for Web of Science ID A1990DW76800001
SPECTRUM STABILITY OF A BROAD-BAND 1060 NM ND-DOPED FIBER LASER ELECTRONICS LETTERS FESLER, F., Digonnet, M., Liu, K., Kim, B. Y., Shaw, H. J. 1990; 26 (13): 870-872
View details for Web of Science ID A1990DM82200027
CHARACTERIZATION AND OPTIMIZATION OF THE GAIN IN ND-DOPED SINGLE-MODE FIBERS IEEE JOURNAL OF QUANTUM ELECTRONICS Digonnet, M. J., Liu, K., Shaw, H. J. 1990; 26 (6): 1105-1110
View details for Web of Science ID A1990DZ86600018
ELECTRONICALLY TUNABLE, 1.55-MUM ERBIUM-DOPED FIBER LASER OPTICS LETTERS WYSOCKI, P. F., Digonnet, M. J., Kim, B. Y. 1990; 15 (5): 273-275
An erbium-doped, silica-based fiber laser was electronically tuned over two ranges from 1529.6 to 1533.3 nm and from 1543.8 to 1563.0 nm with more than 13 mW of maximum power. The tuning element was an intracavity acousto-optic modulator (Bragg cell) configured to feed back the first-order, frequency-shifted deflected beam. The maximum optical/acoustic tuning coefficient was -15 nm/MHz.
View details for Web of Science ID A1990CR02800008
SPECTRAL CHARACTERISTICS OF HIGH-POWER 1.5 MU-M BROAD-BAND SUPERLUMINESCENT FIBER SOURCES IEEE PHOTONICS TECHNOLOGY LETTERS WYSOCKI, P. F., Digonnet, M. J., Kim, B. Y. 1990; 2 (3): 178-180
View details for Web of Science ID A1990CU22400010
ANALYSIS OF A 1060-NM ND-SIO2 SUPERFLUORESCENT FIBER LASER JOURNAL OF LIGHTWAVE TECHNOLOGY Digonnet, M. J., Liu, K. 1989; 7 (7): 1009-1015
View details for Web of Science ID A1989AC09800001
BROAD-BAND DIODE-PUMPED FIBER LASER ELECTRONICS LETTERS Liu, K., Digonnet, M., FESLER, K., Kim, B. Y., Shaw, H. J. 1988; 24 (14): 838-840
View details for Web of Science ID A1988P309900008
SINGLE-MODE FIBRE-OPTIC COMPONENTS JOURNAL OF THE INSTITUTION OF ELECTRONIC AND RADIO ENGINEERS Digonnet, M. J., Kim, B. Y. 1988; 58 (5): S66-S78
View details for Web of Science ID A1988Q658000002
ND-MGO-LINBO3 CONTINUOUS-WAVE LASER PUMPED BY A LASER DIODE OPTICS LETTERS CORDOVAPLAZA, A., Fan, T. Y., Digonnet, M. J., Byer, R. L., Shaw, H. J. 1988; 13 (3): 209-211
Diode-pumped laser oscillation was achieved in Nd:MgO:LiNbO(3). The absorbed pump power thresholds were as low as 1.9 mW for the high-gain or pi polarization and 8 mW for the low-gain polarization. A cw output power of 2 mW was obtained for the pi polarization at lambda = 1.085 microm for 9 mW of absorbed pump power. A slope efficiency of 37% was achieved. The diode-pumped Nd:MgO:LiNbO(3) lasers operated for extended periods of time without exhibiting any reduction in output power.
View details for Web of Science ID A1988M514600010
PULSE CHARACTERISTICS OF Q-SWITCHED FIBER LASERS JOURNAL OF LIGHTWAVE TECHNOLOGY Gaeta, C. J., Digonnet, M. J., Shaw, H. J. 1987; 5 (12): 1645-1651
View details for Web of Science ID A1987L502500001
10MW SUPERFLUORESCENT SINGLE-MODE FIBER SOURCE AT 1060-NM ELECTRONICS LETTERS Liu, K., Digonnet, M., Shaw, H. J., Ainslie, B. J., Craig, S. P. 1987; 23 (24): 1320-1321
MINIATURE CW AND ACTIVE INTERNALLY Q-SWITCHED ND-MGO-LINBO3 LASERS IEEE JOURNAL OF QUANTUM ELECTRONICS CORDOVAPLAZA, A., Digonnet, M. J., Shaw, H. J. 1987; 23 (2): 262-266
View details for Web of Science ID A1987F972100020
THEORY OF SUPERFLUORESCENT FIBER LASERS JOURNAL OF LIGHTWAVE TECHNOLOGY Digonnet, M. J. 1986; 4 (11): 1631-1639
View details for Web of Science ID A1986E984500005
THEORY AND IMPLEMENTATION OF A RAMAN ACTIVE FIBER DELAY-LINE JOURNAL OF LIGHTWAVE TECHNOLOGY Desurvire, E., Digonnet, M. J., Shaw, H. J. 1986; 4 (4): 426-443
View details for Web of Science ID A1986A815500009
1.064-MU-M AND 1.32-MU-M ND - YAG SINGLE-CRYSTAL FIBER LASERS JOURNAL OF LIGHTWAVE TECHNOLOGY Digonnet, M. J., Gaeta, C. J., Shaw, H. J. 1986; 4 (4): 454-460
GENERATION OF 22 MW OF 532-NM RADIATION BY FREQUENCY DOUBLING IN TI-MGO-LINBO3 WAVE-GUIDES OPTICS LETTERS Fejer, M. M., Digonnet, M. J., Byer, R. L. 1986; 11 (4): 230-232
ND-MGO-LINBO3 SPECTROSCOPY AND LASER DEVICES JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS Fan, T. Y., CORDOVAPLAZA, A., Digonnet, M. J., Byer, R. L., Shaw, H. J. 1986; 3 (1): 140-148
View details for Web of Science ID A1986AYG4400020
RAMAN AMPLIFICATION OF RECIRCULATING PULSES IN A REENTRANT FIBER LOOP OPTICS LETTERS Desurvire, E., Digonnet, M., Shaw, H. J. 1985; 10 (2): 83-85
We report the generation of a train of 130 optical pulses derived from a single input pulse recirculating in an active reentrant fiber loop. This was achieved in a 810-m-long single-mode fiber loop closed by a fiber directional coupler. Propagation loss and coupler bifurcation of the 1.12-microm signal were compensated for by Raman amplification using 1.064-microm pump pulses. The effects of pump-power fluctuations on the pulse's amplitude stability and background noise are also reported.
View details for Web of Science ID A1985AAU3100011
CHARACTERIZATION OF PROTON-EXCHANGED WAVE-GUIDES IN MGO-LINBO3 OPTICS LETTERS Digonnet, M., Fejer, M., Byer, R. 1985; 10 (5): 235-237
We report the fabrication and characterization of proton-exchanged waveguides in MgO-doped LiNbO(3), a high-optical-damage-threshold material. Results indicate waveguide characteristics similar to those of waveguides fabricated in undoped LiNbO(3) except for slower diffusion rates and freedom from etching of the y face when pure benzoic acid is used as a proton source. An optical-damage threshold of 70 kW/cm(2) was measured at 0.5145 microm in a MgO:LiNbO(3) waveguide, corresponding to a factor-of-2 improvement over undoped LiNbO(3).
View details for Web of Science ID A1985AGA8900014
MEASUREMENT OF THE CORE PROXIMITY IN POLISHED FIBER SUBSTRATES AND COUPLERS OPTICS LETTERS Digonnet, M. J., FETH, J. R., STOKES, L. F., Shaw, H. J. 1985; 10 (9): 463-465
We report recent developments in a technique to measure the thickness of cladding remaining on polished singlemode fiber substrates. This technique relies on the measurement of the throughput attenuation resulting when a drop of liquid of appropriate refractive index is placed on the substrate. Applications to fiber couplers and other all-fiber devices are described.
View details for Web of Science ID A1985APM7300013
THEORETICAL-ANALYSIS OF OPTICAL FIBER LASER-AMPLIFIERS AND OSCILLATORS APPLIED OPTICS Digonnet, M. J., Gaeta, C. J. 1985; 24 (3): 333-342
View details for Web of Science ID A1985ABG9600009
WAVELENGTH MULTIPLEXING IN SINGLE-MODE FIBER COUPLERS APPLIED OPTICS Digonnet, M., Shaw, H. J. 1983; 22 (3): 484-491
Theoretical and experimental studies of wavelength-division multiplexing in a single-mode fiber optic coupler fabricated by mechanical polishing are reported. The variable spacing geometry of the device allows fine tuning of the center wavelength of operation. Wavelength selectivities ranging from 200 to 35 nm have been experimentally demonstrated, with cross talk ranging from 50 to 10 dB. Selectivity control is simply achieved by proper choice of the interaction length of the coupler. The dependence of the multiplexer behavior on all relevant parameters is investigated and found to satisfy predicted results.
View details for Web of Science ID A1983QA66600030
SINGLE-MODE FIBEROPTIC COMPONENTS PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS BERGH, R. A., Digonnet, M. J., LEFEVRE, H. C., Newton, S. A., Shaw, H. J. 1982; 326: 137-142
View details for Web of Science ID A1982PN95700021
ANALYSIS OF A TUNABLE SINGLE-MODE OPTICAL FIBER COUPLER IEEE JOURNAL OF QUANTUM ELECTRONICS Digonnet, M. J., Shaw, H. J. 1982; 18 (4): 746-754
View details for Web of Science ID A1982NN72000037


text:
var express    = require('express');
var bodyParser = require('body-parser');
var app        = express();
var morgan     = require('morgan');
var admin 	= require("firebase-admin");
var request = require('request');
var cors 		= require('cors');
var moment = require('moment');

app.use(cors())

admin.initializeApp({
  credential: admin.credential.cert("prove-it-firebase-key.json"),
  databaseURL: "https://prove-it-efbec.firebaseio.com"
});
//firebase-adminsdk-cpyy9@prove-it-efbec.iam.gserviceaccount.com

// var ref = admin.database().ref('people');
// var testRef = ref.child('test');
//spike ref
var spikeRef = admin.database().ref('spikes');

// configure app
app.use(morgan('dev')); // log requests to the console

// configure body parser
app.use(bodyParser.urlencoded({ extended: true }));
app.use(bodyParser.json());

var port     = process.env.PORT || 8081; // set our port

// ROUTES FOR OUR API
// =============================================================================

// create our router
var router = express.Router();

// middleware to use for all requests
router.use(function(req, res, next) {
	// do logging
	console.log('Something is happening.');
	next();
});

// test route to make sure everything is working (accessed at GET http://localhost:8080/api)
router.get('/', function(req, res) {

	res.json({ message: 'hooray! welcome to our api!' });
});

// test route to make sure everything is working (accessed at GET http://localhost:8080/api)
router.get('/', function(req, res) {

	res.sendFile(__dirname + '/index.html');
});

// on routes that end in /bears
// ----------------------------------------------------
router.route('/submit/:send_id')

	// create a bear (accessed at POST http://localhost:8080/bears)
	.post(function(req, res) {

		var send_id = req.params.send_id;
		var captcha_data;
		console.log(send_id);
	  // g-recaptcha-response is the key that browser will generate upon form submit.
		  // if its blank or null means user has not selected the captcha, so return the error.
		  console.log(req.body.formData);
		  if(req.body['g-recaptcha-response'] === undefined || req.body['g-recaptcha-response'] === '' || req.body['g-recaptcha-response'] === null) {
		  	captcha_data = false;
	  		updateSpikeData(send_id, captcha_data);
		    console.log(captcha_data);
		    return res.json({"responseCode" : 1,"responseDesc" : "Please select captcha"});
		  }
		  // Put your secret key here.
		  var secretKey = "6Lf1DBQUAAAAADmykyLRyf_y1zsn51NVICoQmouO";
		  // req.connection.remoteAddress will provide IP address of connected user.
		  var verificationUrl = "https://www.google.com/recaptcha/api/siteverify?secret=" + secretKey + "&response=" + req.body['g-recaptcha-response'] + "&remoteip=" + req.connection.remoteAddress;
		  // Hitting GET request to the URL, Google will respond with success or error scenario.
		  request(verificationUrl,function(error,response,body) {
		    body = JSON.parse(body);

		    // Success will be true or false depending upon captcha validation.
		    if(body.success !== undefined && !body.success) {
		    	captcha_data = false;
		    	updateSpikeData(send_id, captcha_data);
		    	console.log(captcha_data);
		      	return res.json({"responseCode" : 1,"responseDesc" : "Failed captcha verification"});
		    }
		    captcha_data = true;
		    updateSpikeData(send_id, captcha_data);
		    console.log(captcha_data);
		    return res.json({"responseCode" : 0,"responseDesc" : "Sucess"});
		  });
	});

	// on routes that end in /bears
// ----------------------------------------------------
router.route('/spike')
	// create a bear (accessed at POST http://localhost:8080/bears)
	.post(function(req, res) {

		res.json({"post" : true});

	})

	.put(function(req, res) {
		//root.child('users').child(user.uid).child("username").setValue(newUsername.value);
	  	console.log(req.body.meta_data_collection);
		res.json({'put' : req.body});
	})

	// get all the bears (accessed at GET http://localhost:8080/api/bears)
	.get(function(req, res) {

		var ip = req.connection.remoteAddress;
		var spike = new Spike(ip);

		var response = spikeRef.push(spike);
		console.log('response: ', response);

		console.log(spike);

		res.json(spike);

	});

// ----------------------------------------------------
router.route('/spike/:send_id')

	.put(function(req, res) {
		console.log(req.body);

		var send_id = req.params.send_id;
		var meta_data = req.body.meta_data_collection;
		updatMetaData(send_id, meta_data);
		//root.child('users').child(user.uid).child("username").setValue(newUsername.value);

		res.json({'put' : req.body});
	})

	// get all the bears (accessed at GET http://localhost:8080/api/bears)
	.get(function(req, res) {

		var send_id = req.params.send_id;

		var ref = admin.database().ref("spikes");
		// Test for the existence of certain keys within a DataSnapshot
		ref.orderByChild('send_url_id')
		    .equalTo(send_id)
		    .once('value')
		    .then(function (snapshot) {
		      var value = snapshot.val();
		      	if (value) {
		      		console.log(value);
		      		res.json(value);
		    	}
			});;
});

router.route('/view/:view_id')
	// get all the bears (accessed at GET http://localhost:8080/api/bears)
	.get(function(req, res) {

		var view_id = req.params.view_id;

		// Find all dinosaurs whose names come before Pterodactyl lexicographically.
		var ref = admin.database().ref("spikes");
		// Test for the existence of certain keys within a DataSnapshot
		ref.orderByChild('view_url_id')
		    .equalTo(view_id)
		    .once('value')
		    .then(function (snapshot) {
		      var value = snapshot.val();
		      	if (value) {
		      		console.log(value);
		      		res.json(value);
		    	}
			});
});
// on routes that end in /bears/:bear_id
// ----------------------------------------------------
router.route('/test/:test_id')

	// get the bear with that id
	.get(function(req, res) {
		res.json('test');
	})

	// update the bear with this id
	.put(function(req, res) {
		testRef.push({
			name:"tyson",
			admin:true,
			count:1
		})
		res.json('pong');
		res.json({ message: 'test!' });
	})

	// delete the bear with this id
	.delete(function(req, res) {

		res.json({ message: 'test' });
	});

// REGISTER OUR ROUTES -------------------------------
app.use('/', router);

// START THE SERVER
// =============================================================================
app.listen(port);
console.log('Magic happens on port ' + port);

function Spike(ip) {
	this._id;
    this.send_base_url = 'http://localhost:8080/spike/';
    this.send_url_id = _smallid();
    this.view_base_url = 'http://localhost:8080/view/';
    this.view_url_id = _smallid();
    this.time_created = moment().format('YYYY-MM-DD hh:mm:ss');
    this.time_started;
    this.time_completed;
    this.pass;
    this.flagged = false;
    this.destructed = false;
    this.archive = false;
    this.created_by = {
        ip: ip,
        country_code: null
    },
    this.meta_data_collection = {
        ip_address: null,
        browser: null,
        device: null,
        country_code: null,
        location: null,
        postal_code: null,
        approximate_coordinates: [],
        accuracy_radius: null,
        isp: null,
        orginization: null,
        domain: null,
        metro_code: null,
        email: null,
        email_domain: null,
        phone_numbers: [],
        user_names: []
    };
    this.captcha_data = {
    };
    this.threat_levels = {
        ai_bot: null,
        proxy: null
    };
    this.logging = [];
}

//generate guids
function _guid() {
	function s4() {
		return Math.floor((1 + Math.random()) * 0x10000)
		.toString(16)
		.substring(1);
	}
	return s4() + s4() + '-' + s4() + '-' + s4() + '-' +
	s4() + '-' + s4() + s4() + s4();
}

//generate small ids
function _smallid(){
    var id = "";
    var idLength = 11;
    var possible = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";

    for( var i=0; i < idLength; i++ )
        id += possible.charAt(Math.floor(Math.random() * possible.length));

    return id;
}

function updateSpikeData(send_id, captcha_data) {
	var spike = admin.database().ref('spikes').child(send_id);
	spike.update({
	  captcha_data: captcha_data
	});
	console.log('firebase update', send_id);
}

function updatMetaData(send_id, meta_data) {
	var spike = admin.database().ref('spikes').child(send_id);
	spike.update({
	  meta_data_collection: meta_data
	});
	console.log('firebase update',send_id);
	console.log('meta_data', meta_data);
}

redpajama_set_name: RedPajamaGithub


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text:
Entrepreneurship, Specialized Master's Programs
11 questions with MS in Entrepreneurship student Emileigh Thylin
We asked current Foster students to tell us why they chose Foster, what they like to do for fun, and to share advice with potential applicants. Meet Master of Science in Entrepreneurship student Emileigh Thylin.
MS in Entrepreneurship student Emileigh Thylin
1) Where are you from?
San Jose, CA!
2) What did you do before entering this program?
Nine days before starting this program, I graduated from the UW's Foster School of Business with my B.A. in Business Administration with a concentration in Entrepreneurship.
3) Did you have any entrepreneurship experience before entering this program?
Emileigh getting ready for a Seattle Strong coffee delivery
Yes! I've worked for a variety of startups in a variety of industries. In April, I started the coffee company that would become my focus during the MS ENTRE program: Seattle Strong.
4) Tell us why you are excited to be a part of the inaugural MS in Entrepreneurship class
Being part of the inaugural MS ENTRE class is an honor and a privilege for many reasons. This is a program that UW faculty have been working on for years, that professionals around Seattle are enthusiastic about, and that is tailored to the needs of the students. Dozens of people came together to contribute to our curriculum. Entrepreneurs joined forces with professors to create a well-rounded program that dives into the most important lessons for every entrepreneur, providing us with in depth building blocks of what it takes to start a company. Most importantly, the small cohort gives us the ability to work with faculty and staff to dive deeper into subjects and topics that interest us. Program administrators are more than happy to arrange additional events and workshops that build on the needs and desires of students. We are encouraged to ask for what we need, and they do their best to meet those needs.
5) What are your thoughts on the entrepreneurship scene in Seattle?
SO FUN! Seattle is an incredible place with incredible people. The diversity, progressiveness, and entrepreneurial spirit of the city combine to create an entrepreneurial scene unlike any other. Seattle is a proud city. People from Seattle (generally) love things from their city. Consequently, the Seattle community in general is really accepting of new businesses taking flight in their city. More established companies and organizations sponsor incredible opportunities for anybody to pursue their dreams. For instance, Seattle Startup Week allows anyone and everyone to access free events where they can learn about things that interest them.
6) What connections are you hoping to make while in the program?
I have already made a considerable amount of connections, although it has only been one quarter! I hope to continue connecting with like-minded individuals who also yearn to create change.
7) Where do you see yourself in 5 years?
Wherever the wind takes me! Over the next 5 years, I would love to continue working on Seattle Strong, I would love to contribute to other startups, or maybe pursue a PhD—I would love to teach one day and encourage others to start their own company!
8) What skills and/or knowledge are you looking to develop?
I'm hoping to gain a better understanding of scaling a startup from nothing to a well-known reputable brand, how to be a leader, and how to engage a community. I'm confident that by the end of the program I will have developed these skills significantly.
9) What do you like to do for fun?
I love attending events around Seattle, reading, hiking, hanging out with other entrepreneurs and friends, brainstorming ways in which the world could change, etc.
Emileigh hiking with classmates
10) What's been your favorite part of the program so far?
It's so challenging to pick just one—but if I had to, I would say all the people who have invested so much of their time and energy to helping us. The mentors and outstanding faculty are passionate about this program and have so much to offer all of the students. The small cohort size allows for us to not only create strong relationships with each other, but with our professors and mentors. My professors know my name, they know my company, and they are able to tailor lessons and advice to things that are relevant to me and the rest of the students. The mentors come from a wide variety of industries and backgrounds and volunteer their time, energy and expertise to share their knowledge with us.
11) What advice would you give to someone who's thinking about applying to the MS in Entrepreneurship program?
DO IT! I won't lie, I had my hesitations at first, too. Entrepreneurs have a reputation for dropping out, right? So, going to a master program for entrepreneurship seemed rather counter-intuitive initially. After talking to some very influential people in my life, I was persuaded to do the program. They told me, "You go to college to learn. But more importantly, you go to meet people." Since being in this program I have met so many incredible individuals. Game changers. Innovators. Experienced professionals with incredible skills. My network has expanded vastly, from MS ENTRE students to other UW master students, to professionals in the greater Seattle areas.
Learn more about the Master of Science in Entrepreneurship program
Sign up for the MS in Entrepreneurship email list
Attend an MS in Entrepreneurship admissions event
Visit the MS in Entrepreneurship website
This post is part of a series where we ask current students to answer 11 questions about their experience at Foster. Stay tuned for more interviews in the coming weeks!
11 questions, coffee, Master of Science in Entrepreneurship, Master of Science in Entrepreneurship student experience, Seattle, Student Experience
11 questions with MSCM student Claudia Gutierrez
11 questions with MSIS student Monique Smith
About the MS in Entrepreneurship Program
The 12-month Master of Science in Entrepreneurship degree program was built for entrepreneurs, by entrepreneurs. As rigorous as an MBA, our program follows the same path as a startup—with a curriculum designed to guide you through a real-world entrepreneurial process used to develop new companies.
It's the one-year launchpad that will make the most difference in your business, by equipping you with the tools, skills, and connections to confidently lead your next company to success.
We consider Seattle to be a global innovation hub and the ideal place to gain the confidence, competence, and community to launch and grow your new venture! Get in touch to learn more about the program, to set up a phone call with an admissions representative, or to arrange a (virtual) class visit.
Sign up to receive updates about MS ENTRE news and events Sign up
Upcoming MSEntre Events
MSEntre Posts by Topic
Specialized Master's Programs

redpajama_set_name: RedPajamaCommonCrawl