"You are a pretty doodle girl!"
"Yippee!!!! The Ross Family Dogs 5394 Brantford Avenue Memphis, TN 38120"
"He is beautiful! He is going to bring you so much joy! <3"
Three Doodle Life replied to Lori, Daphne, Lucy & Pippa's discussion This is a BIG ONE! Need ALL members!
"Done! Love this picture of Miss Daphne!"
"I love it too! Mozzie is gorgeous and his mommy has a great sense of humor. :O)"
"She's beautiful, Lynda! Mona Chica sounds perfect! :-)"
"Our Mozzie leaps over a tall baby gate with effortless grace. Our other doodle Beowoof doesn't even try it. Though, Mozzie easily stands five inches taller than his brother. :-)"
"That is fantastic news, Lynda! I can't wait to see pictures. :-)"
Three Doodle Life replied to Tara's discussion Today is Doodle Day!!!!!
"Congratulations! Seymour is a handsome little gentleman. :-)"
Three Doodle Life replied to Lori, Rooney & Zuzu's discussion We are now a DOUBLE DOODLE family!
"Zuzu is a doll! Congratulations on your 2nd doodle!"
Three Doodle Life replied to Gina's discussion Oakley's first haircut!
"He looks great! Very handsome!!"
Just hanging' with my Peeps!
"Beautiful doodle girls! I always enjoy their photos. :-)"
I am an artist and my husband Lloyd is a data analyst. We have a 6 year old daughter named Zofia and a 28 year old son named Joe. We also have two grandsons, Wyatt & Walker.
Beowoof - Our red F1b English Goldendoodle who was born on July 23, 2013. He is a big cuddly lovebug sweetheart of a dood!
Mozzie - Our chocolate multigen Goldendoodle who was born on May 10, 2015.
Coconut - Our newest doodle addition. She is Mozzie's mom and just retired from breeding in May 2018. She needed a forever home and we were thrilled to adopt her! She is 5 years old and sweet as the day is long.
Oonaugh - 11 years old. She is a liver/pepper schnauzer. She's also our alpha and likes to remind everyone of that fact!
Talulla - 11 years old and Oonaugh's littermate sister. She is a salt & pepper schnauzer. She is small but mighty and has eyelashes for days.
We had been considering getting a Giant Schnauzer but met a Goldendoodle at a Panera Bread one morning. He was such a sweet gentleman doodle sitting next to his owners at a table outside. We were amazed at his disposition! After researching the breed for several months we decided a Goldendoodle would be the right fit for our family.
OMD...I got your amazing Christmas card. I cannot believe you have 5 dogs. I am watching my two grand dogs and four seems like A LOT to me :) I think it is great...for you. LOL Your dogs are all so adorable. Merry Christmas!!
Your doodles are so cute I would love to have another one to go with Jake. Thank you for your Christmas card, and have a nice Christmas.
My husband is such a good sport. I just told him the sweater was in on the bed, he put it on, we snapped the photo, and the card was done. LOL I can certainly tell you where to get one for your husband :) Thank you. I am so behind this year in going through my cards. I have a whole stack to open this weekend! Can't wait to see your card.
Thanks so much! Looking forward to your card with adorable Beowoof!! Wishing you and your family a wonderful Christmas!
thanks so much Vanessa! Beowoof is such a great name :) I don't think we got your card yet - but we can't wait to get it!
Thanks for the comments on Tugboat's card. Your Beowoof is adorable! Looking forward to your card. We miss our Tuggy, as we're vacationing right now, but he's in good hands with a housesitter. Happy Holidays!
Thank you for the nice comment, Vanessa! It's a wonder what a couple of treats can do. Overall, the girls were cooperative, but I think Angel was just hoping it would end so she could get that wreath off! BTW, love the name Beowoof! So cute. Can't wait to get the card of him and his Schnauzer pals!
Thank you so much :) Can't wait for yours to arrive Vanessa!!! Beowoof is so adorable. We love Schnauzers too, Kona and Buddy have many Schnauzer friends we train with.


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Innovative and custom web design from Hannover, Germany. Starting with your wishes and ideas, through consultation and design to the finished website it is important for us to understand what you need and want.
The personal service in consulting, design and development is our primary goal. We want to know about you and your business to build a website that fits.
Our focus is on websites for self-employed, small and midsize companies. It's important for us to maintain the relationship even after the website is finished to advise and cooperate.
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Webdesign Haas offers a complete package for your individual appearance in public, from business cards and advertising and stationery to web design.
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Homepage design and development: We build your new homepage based on an existing design or in collaboration with a graphic designer. We build your web site with the content management system M-CMS. That way you can easily change text and images yourself or add new pages and content.


You might believe cats are indifferent, with a 'couldn't care less' attitude, but this film reveals cats as more complex, interesting and even cuter than you can imagine. As we witness the astonishing transformation a new-born kitten makes when growing into a fully-grown cat, we discover the amazing, secret life of cats..
With the balance of a ballerina, senses so acute they can see what's invisible to us, and unique social skills they're deservedly the most popular pets in Britain. No matter whether your cat's the latest pedigree breed or common-or-garden household moggy, brand new filming techniques uncover the awe-inspiring qualities each and every one of them possesses.
This beautifully shot film is also jam packed with heart-warming stories of cats who take care of their owners, who save lives and who have survived against the odds.


For any filmmaker, dramatizing the life and times of a well-known and highly documented individual frequently stands as a no-win situation. Change too much and people will question your ethics as a storyteller. Change nothing are you are left with the alienating chaos of real life.
On the surface, Ernest Hemingway would seem to be the ideal model for a film adaptation. Between his travels, his demons and his relationships, Hemingway seemed to live every moment of his life in the hope that someone would make a movie of it.
That last example serves as the basis of the HBO film Hemingway & Gellhorn, which chronicles the (of course) tumultuous affair between the author (Clive Owen) and famed war correspondent Martha Gellhorn (Nicole Kidman).
Upon watching the film, one quickly realizes that the ordering of the names in the title is bit of a misnomer, as it is Gellhorn who plays the central figure in this tale. The film itself is even structured via the device of having an elder Gellhorn giving her life story to a documentary crew.
The story naturally begins with the first meeting between Gellhorn and Hemingway at a bar in the Key West in 1936. By this point, Hemingway is already the talk of the literary town with the release of such book as The Sun Also Rises and A Farewell to Arms. The two instantly find that they have a natural rapport and, despite the fact that Hemingway is already married, find themselves drawn to one another.
The two then travel to Spain in order to help film footage for a documentary on the Spanish Civil War. There, the sparks truly ignite. Shortly afterwards, Hemingway divorces his wife, and the two marry. But, as anyone familiar with history knows all too well, a happy ending was not in the cards.
Throughout the story, the filmmakers make it abundantly clear that they've done their homework. A bit too clear, perhaps. Hemingway & Gellhorn is the kind of film where characters recite their respective résumés upon first entering a scene, and the screenwriters awkwardly incorporate famous quotations from the real-life individuals into the dialogue.
Certainly one expects a bit more from the likes of director Philip Kaufman, who has extensive experience in dramatizing the lives of famous writers such as Henry Miller (Henry & June) and Marquis de Sade (Quills).
Likewise, co-writer Barbara Turner also penned the fantastic 2000 Jackson Pollock biopic Pollock while co-writer Jerry Stahl, like Hemingway, brings with him a well-documented history of substance abuse and self-destructive behavior (Permanent Midnight). Rather than these individuals pooling their resources together to make something special, however, the result is an entertaining but often plodding biopic that makes one long for the power and passion found in some of those other credits.
Made on a modest budget, the production does an admirable job at conveying the film's vast, globe-trotting scope. Where the proverbial strings begin to show comes with the decision to digitally insert the actors, Zelig-style, into archival footage. While this technique works adequately at times, it fails miserably at others. For instance, a scene towards the end where Gellhorn's horrified face is superimposed over real-life footage of dead bodies at the Auschwitz concentration camps feels horrifically inappropriate.
Furthermore, the filmmakers' predilection for beginning each scene with a grainy, sepia-toned and/or black-and-the-white news footage aesthetic too often evokes the kind of cheap production value that they try so hard to circumvent.
In terms of the acting, there's little room for complaint. At 45, Kidman remains a fetching and powerful screen presence. Here, she captures Gellhorn's idealistic, gung-ho leftism without making herself sound overly self-righteous.
Moreover, few actors are better suited to the role of Hemingway than Clive Owen. Yet, while Owen easily embodies Hemingway's extraordinary charisma (and certainly his legendary temper), his performance is often undermined by the British actor's inability to hold his American accent. Owen may very well be one of the great actors working today but—like Anthony Hopkins and Michael Caine before him—his rich English baritone is far too distinctive to mask.
Though Kidman and Owen are certainly not without chemistry, the script does them little favors. As written and portrayed in the film, Gellhorn and Hemingway come across less like fully formed characters and more like Bogart-Bacall archetypes that just happen to be based on real people. For their part, Kaufman, Turner and Stahl seem more interested in feeding into Gellhorn's and Hemingway's overstuffed, legendary personas rather than bringing them down to earth and portraying them as the flawed, yet compelling characters they no doubt were.
Worse yet, the film starts to lose its footing the moment the two become a couple. For instance, the scene where Gellhorn and Hemingway finally consummate their relationship occurs, of all places, during a barrage on their hotel where debris falls from the ceiling and walls collapse around them. This juxtaposition between the couple's impassioned coupling and destructive wartime imagery is, at once, both laughable and highly distasteful.
Likewise, though Kaufman coaxes some fun performances from Robert Duvall, David Strathairn and Tony Shalhoub (even infamous Metallica drummer Lars Ulrich manages to hold his own in a roomful of professionals), the parts are often too brief to leave much of an impression.
The overall result is a film that more closely resembles an expensive and glorified game of "make believe" than the epic story about war and love that it aims to be.


text:
Keyword: Swiss Agency for Development and Cooperation
Vietnam gets help to apply remote sensor tech in rice cultivation
Vietnam is receiving support to apply remote sensor technology in rice production.
Community management employed in new rural building
A conference was held in the northern province of Vinh Phuc on November 15 to review a Swiss-funded project on community management in the national target programme on building new - style rural areas
Switzerland helps Vietnam develop economy sustainably
Saturday, October 01, 2016 16:00
Switzerland will push ahead economic partnership with Vietnam to help the Southeast Asian country achieve sustainable economic growth.
Vietnamese traditional music and culture show
Chuyen Nhac Pho Co is celebrating its special show at the Old Quarter Culture Exchange Centre, 50 Dao Duy Tu Street, from July 8 to 18.
Mekong countries share land governance experiences
Tuesday, June 21, 2016 16:00
Government officials from Cambodia, Laos, Myanmar and Vietnam, which border the Mekong River, shared land governance experiences at a forum which opened in Hanoi on June 21.
Over 300 million USD for urban development in Can Tho
Up to 322 million USD will be poured into developing the Mekong Delta city of Can Tho and strengthening its urban adaptability under a project launched on June 3.
Oxfam launches project to benefit Vietnam's poor
Sunday, March 30, 2014 18:36
Oxfam in Vietnam on March 28 launched its new project on "Pro-poor Policy Monitoring and Analysis in Vietnam", which will be carried out in 10 provinces and cities nationwide between 2014 and 2016, the Communist Party of Vietnam's online newspaper reported.

redpajama_set_name: RedPajamaCommonCrawl


text:
Coherent multi-heterodyne spectroscopy using acousto-optic frequency combs
Vicente Durán, Cȏme Schnébelin, and Hugues Guillet de Chatellus
Vicente Durán,1,2,* Cȏme Schnébelin,1 and Hugues Guillet de Chatellus1
1Univ. Grenoble Alpes, CNRS, LIPhy, F-38000 Grenoble, France
2GROC•UJI, Institut of New Imaging Technologies, Universitat Jaume I, 12070 Castelló, Spain
*Corresponding author: vduran@uji.es
Hugues Guillet de Chatellus https://orcid.org/0000-0003-2075-4056
V Durán
C Schnébelin
H Guillet de Chatellus
Vicente Durán, Cȏme Schnébelin, and Hugues Guillet de Chatellus, "Coherent multi-heterodyne spectroscopy using acousto-optic frequency combs," Opt. Express 26, 13800-13809 (2018)
Optimization of acousto-optic optical frequency combs
Nithyanandan Kanagaraj, et al.
Arbitrary energy-preserving control of the line spacing of an optical frequency comb over six...
Hugues Guillet de Chatellus, et al.
All-optical coherent pulse compression for dynamic laser ranging using an acousto-optic dual comb
Vincent Billault, et al.
High resolution spectroscopy
Injection locking
Molecular spectroscopy
Interferometry (120.3180)
Spectrometers and spectroscopic instrumentation (120.6200)
Lasers, fiber (140.3510)
Spectroscopy, heterodyne (300.6310)
2. Characterization of acousto-optic FCs
3. Self-heterodyne spectroscopy
4. Dual-comb spectroscopy
5. Conclusions and discussion
We propose and characterize experimentally a new source of optical frequency combs for performing multi-heterodyne spectrometry. This comb modality is based on a frequency-shifting loop seeded with a continuous-wave (CW) monochromatic laser. The comb lines are generated by successive passes of the CW laser through an acousto-optic frequency shifter. We report the generation of frequency combs with more than 1500 mutually coherent lines, without resorting to non-linear broadening phenomena or external electronic modulation. The comb line spacing is easily reconfigurable from tens of MHz down to the kHz region. We first use a single acousto-optic frequency comb to conduct self-heterodyne interferometry with a high frequency resolution (500 kHz). By increasing the line spacing to 80 MHz, we demonstrate molecular spectroscopy on the sub-millisecond time scale. In order to reduce the detection bandwidth, we subsequently implement an acousto-optic dual-comb spectrometer with the aid of two mutually coherent frequency shifting loops. In each architecture, the potentiality of acousto-optic frequency combs for spectroscopy is validated by spectral measurements of hydrogen cyanide in the near-infrared region.
© 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
Optical frequency combs (FCs) have become key measurement tools in optical metrology and high-precision spectroscopy. They can be produced in a variety of ways, depending on the targeted application. Femtosecond mode-locked lasers are the most common sources of frequency combs, providing thousands of narrow teeth [1]. When femtosecond combs are fully stabilized they turn into extremely precise optical frequency rulers [2]. These capabilities have been exploited in diverse areas, including optical clocks, molecular spectroscopy and distance ranging [3–6]. However the line spacing, or free spectral range (FSR), is set by the length of the laser cavity and is usually limited to values below the GHz range. This can be a critical issue for important applications, such as astronomical spectrograph calibration [7] or optical telecommunications [8]. Another limitation of femtosecond FCs is the relative complexity of self-referencing techniques to control the comb absolute frequency. A different way of generating phase-locked FCs with controlled absolute frequency consists of seeding a high-finesse resonator with a CW laser: regularly spaced comb lines are generated by non-linear interactions in the resonator. Combs with FSR ranging from 1 GHz to 1 THz have been reported in microresonators [9, 10]. This technology also offers the possibility of on-chip integration [9], self-referencing [11] and promising prospects for microwave photonics [12], dual-comb spectroscopy [13] and coherent optical telecommunications [14, 15]. However, similarly to femtosecond frequency combs, the FSR is directly fixed by the length of the resonator.
Alternatively, a relatively simple manner of producing combs with flexible FSR (up to tens of GHz), and tunable central frequency, is based on the modulation of a CW laser using electro-optic modulators [16]. The line spacing is set by the radio-frequency (RF) function generator driving the modulators, while the central frequency is determined by the CW laser. Besides, the generation of the so-called electro-optic FCs is particularly simple with conventional telecommunications components. Apart from their versatility, electro-optic FCs have recently aroused great interest for conducting dual-comb spectroscopy, since the two combs that are involved in that technique can be produced from a single CW laser. This feature ensures a high degree of mutual coherence without resorting to sophisticated phase-locking schemes [17–19]. Beyond spectroscopy, electro-optic dual-comb interferometers have been applied to optical waveform characterization [20, 21], laser ranging [22] and vibrometry [23, 24]. However, despite the above advantages, electro-optic FCs suffer from a relatively low number of teeth (typically <100). Different techniques have been proposed to increase the number of spectral lines. Non-linear broadening in a highly nonlinear fiber has proven successful to increase the number of lines by one order of magnitude, enabling frequency-agile dual-comb spectroscopy [19] or optical waveform characterization over the entire C-band [25]. Indeed, two successive spectral broadening stages, combined with an f-2f self-referencing interferometer, have been applied to reach a bidirectional frequency conversion between the microwave and optical domains [26]. Alternatively, spectroscopy with hundreds of lines can be conducted when the electro-optic modulation is driven by step-recovery diodes [27] or phase bit sequences [28, 29]. This avoids increasing the complexity of the comb-based systems by the insertion of a nonlinear broadening stage. An electro-optic frequency comb driven by random phase modulation has been employed, for instance, to perform dynamic atomic spectroscopy with high-precision frequency resolution (10 MHz) [30]. The extension to molecular spectroscopy has been subsequently demonstrated with a hybrid dual-comb setup, including a mode-locked frequency comb [31]. However, in these phase modulation techniques the spectral bandwidth of the FC is ultimately limited by the bandwidth of the function generator (a few tens of GHz). Another approach that has been proposed to produce FCs from a CW laser combines gain-switching and optical injection locking in a semiconductor laser [32, 33]. This method makes it possible to achieve dual-comb generation (potentially from visible to mid-infrared), although the spectra thus obtained are still limited to tens of lines.
Here we propose and implement a simple source of optical FCs, providing more than 1000 mutually coherent lines from a single CW laser, with a FSR reconfigurable in the range from kHz to tens of MHz. Our technique makes no use of non-linear media, nor fast electronic function generators. It is based on a simple frequency-shifting loop (FSL) seeded by a CW laser [34–38]. The comb lines are produced by successive frequency shifts in the loop. This optical system can be implemented in a straightforward manner with an acousto-optic frequency shifter (AOFS). Notice that seeded FSLs have been previously employed for generating pulse trains with tunable and ultrahigh repetition rates [35], as well as for performing optical real-time Fourier transformations [37, 38]. These time-domain applications take advantage of the temporal Talbot effect, which is originated by the controllable spectral quadratic phase exhibited by the comb modes [36]. In the frequency domain, it has been shown that acousto-optic frequency shifting loops can generate relatively flat spectra composed of >1000 modes [39]. However, the use of this kind of comb sources for spectroscopic applications has remained so far unexplored. In this paper, we uncover the potentiality of acousto-optic FCs for multi-heterodyne spectroscopy with high spectral resolution. In a first set of experiments, we demonstrate self-heterodyne interferometry [28, 30] for measuring the transmission peaks of a Fabry-Pérot cavity with a sub-MHz resolution. Then, by extending the tooth spacing to tens of MHz, we report molecular spectroscopy on the sub-millisecond time scale, albeit at the expense of using a detector with a relatively large RF bandwidth (broader than the measured absorption line). In order to efficiently down-convert the optical frequencies to the RF domain, we finally explore the possibility of implementing a dual-comb setup with a pair of FSLs. With this second technique, molecular spectroscopy is achieved with a down-conversion factor >1000. In the conclusions, the prospects of acousto-optic frequency combs for spectroscopic and metrology applications, along with their limitations, are briefly discussed.
The generation of acousto-optics FCs is based on a fiber frequency-shifting loop (FSL) [Fig. 1(a)]. In a first implementation, the loop includes two acousto-optic frequency shifters (AOFS 1 and AOFS 2) driven by an RF waveform generator. They induce frequency shifts with opposite signs (an upshift of 80 MHz and a downshift of 79 MHz). As a consequence, every roundtrip, the light frequency is shifted by fs = 1 MHz. The fiber FSL also includes an Er-doped fiber amplifier (EDFA) to compensate for the loop losses, an isolator, and a tunable band-pass filter (BPF). The purpose of this filter is to control the spectral bandwidth of the comb, and to reduce the amplified spontaneous emission (ASE) generated by the EDFA. The FSL roundtrip time is close to 100 ns. The FSL is seeded by a narrow linewidth (<1 kHz) laser emitting at 1550 nm. Two 90:10 fiber couplers are employed, respectively to seed the FSL and to extract a fraction of the light circulating inside the loop, following a configuration similar to that reported in [37]. In order to visualize the lines of the generated frequency comb, we perform self-heterodyne interferometry: the light coming from the loop is mixed with the seed laser (acting as a coherent local oscillator, LO) and the beating signal is detected by a photodiode (PD). The light power in both arms of the interferometer is boosted by means of two additional EDFAs [not shown in Fig. 1(a)]. The photocurrent is digitized by an 8-bit oscilloscope and analyzed offline. The RF spectrum of the detected signal contains the beat notes between every comb line and the seed laser. A third acousto-optic modulator (AOFS 3), inducing a frequency shift of 79.5 MHz, is added to the interferometer, in order to separate the beatings of interest (i.e. the ones obtained by mixing with the seed laser) from the intra-mode beatings (i.e. the ones due to the beatings of the comb with itself). All the optical components use polarization-maintaining fiber.
Fig. 1 (a) Sketch of the experimental setup used to generate and resolve the individual lines of an acousto-optic frequency comb by self-heterodyne interferometry. The inset shows a 1-µs fraction of a complete recorded trace. (b) RF spectrum obtained by self-heterodyning showing 1800 lines within 10 dB. The right inset is a zoom-in view of the central part of the spectrum, showing 100 lines separated from each other by 1 MHz.
A typical optical frequency comb produced by the FSL is shown in Fig. 1(b). This spectrum is obtained for an acquisition time of 200 µs. Since the net frequency shift is positive, high RF frequencies correspond to high optical ones. The frequency comb shown in Fig. 1(b) contains around 1800 lines within 10 dB. A zoom-in view of the comb showing individual lines at the central part of the spectrum (around 0.9 GHz) can be observed in the right plot. As expected, the frequency comb has a line spacing given by fs = 1 MHz. Here, the total spectral bandwidth is limited by the BPF but, in return, the power spectrum (in dB) undergoes a roughly linear decrease of only 0.56 dB/100 lines. This slope can be adjusted to increase the signal-to-noise ratio (SNR) of the comb lines at the beginning of the spectrum, at the expense of limiting the usable bandwidth. Notice that by inserting in the loop a single AOFS, which typically introduces frequency shifts of tens or a few hundreds of MHz, the measurement of the acousto-optic FC by heterodyning with the seed laser would require a significantly larger detection bandwidth. An alternative technique would involve a high-resolution optical spectral analyzer. Such a measurement, conducted in [39], demonstrates an acousto-optic FC with an optical bandwidth of 96 GHz and 1200 lines.
3.1 Self-heterodyne spectroscopy with sub-MHz spectral resolution
The setup displayed in Fig. 1 can generate frequency combs with an FSR easily reconfigurable, from 20 MHz (the maximum frequency difference between the two AOFSs), down to the sub-MHz frequency range. In order to demonstrate the capability of the system for high spectral resolution spectroscopy, we insert after the FSL a Fabry-Pérot cavity with a FSR of 1.6 GHz and a finesse of 250. When the line spacing is set to 5 MHz, successive transmission peaks are clearly observed in the RF frequency comb (left plot in Fig. 2, dark blue curve). This spectrum is retrieved from the Fourier transformation of a 1-ms temporal trace. Here, it is limited by the bandwidth of the oscilloscope used as digitizer. Apart from the longitudinal resonances, which are separated by the FSR, transverse modes arising from spatial mode mismatch between the laser beam and the cavity mode, are also visible in the spectrum. To determine the cavity transmission function, the comb spectrum is normalized thanks to a reference measurement performed without the resonator (left plot in Fig. 2, light blue spectrum). Due to the interferometric nature of this spectrometer, we can also retrieve the spectral phase, obtained as the difference of the phase profiles with and without the cavity. The complex response of the cavity around a single resonance is shown in Fig. 2 (central plot), where the points correspond to the values retrieved at the comb lines frequencies. Notice that a comb FSR equal to 5 MHz is too large for properly resolving (in both power and phase) the transmission peak. This limitation can be solved by reducing the frequency offset between the AOFSs down to 500 kHz. This configuration provides a zoom-in view of the complex amplitude around the resonance (green area), as is shown in Fig. 2 (right plot). In this case, the transmission and phase profiles around the cavity resonance peak are clearly visible.
Fig. 2 Left. Dark blue: transmission spectrum of the Fabry-Pérot cavity (FSR = 1.6 GHz). Light blue: reference spectrum (no cavity inserted). The line spacing is 5 MHz. Center: Complex amplitude of a single transmission peak. The phase curve shows the expected π-jump. Right: Zoom-in view of the transmission peak (green area in the central plot) when the line spacing is reduced to 500 kHz.
3.2 Self-heterodyne molecular spectroscopy
In a second set of experiments, we apply self-heterodyne interferometry to conduct fast molecular spectroscopy. We use the experimental setup shown in Fig. 3(a), which includes a FSL with a single frequency shifter (AOFS 1) to generate a comb with a line spacing of 80 MHz. With this setup, we report the measurement of an absorption line of hydrogen cyanide (H13C14N), a common wavelength reference in the C-telecommunications band [4, 18, 19]. To this end, we place a fiber-coupled HCN cell (pressure: 25 Torr, length: L = 5.5 cm) after the FSL. Here, the CW laser is replaced with a diode laser tunable around 1550 nm and with a linewidth < 500 kHz. This laser allows us to measure the complex amplitude of the 11th line in the HCN P-branch (line P11). In order to obtain a reference measurement (without cell), a 3dB coupler splits the signal arm into two parts, one containing the fiber gas cell, and the other one a frequency shifter inducing a negative shift (AOFS 2, driven at 87 MHz). By means of two 3dB couplers, the light coming from both arms is mixed with the LO [17]. As before, the light frequency in the LO arm is shifted by a third acousto-optic modulator (AOFS 3, driven at 78 MHz), to separate the intra-mode beat notes from the spectrum of interest. The power of both interferometer arms are boosted by two additional EDFAs [not shown in the Fig. 3(a)]. Apart from the intra-mode beat notes, the RF spectrum of the photodiode signal is composed of two interleaved combs: one corresponds to the absorption profile, and the other one to the reference measurement. Since self-heterodyne interferometry provides a direct mapping of the optical spectrum into the RF domain (i.e., the spectral scaling factor, or compression factor, is 1), the measurement of the whole molecular absorption line requires the use of a broadband (8-bit) oscilloscope (bandwidth >8 GHz).
Fig. 3 (a) Sketch of the experimental setup used to perform self-heterodyne molecular spectroscopy of HCN. (b) Transmission and phase corresponding to the 11th line of the HCN P-branch. In the transmission curve, the red line is the Voigt profile that fits the experimental data (in blue) and the green squares plotted below are the corresponding residuals. In the phase plot, the red curve corresponds to the theoretical function derived from the Voigt profile.
In order to measure the molecular transition, a set of 25 temporal traces is recorded. Each one has a duration of 20 µs. The complex amplitude response (transmission and phase) retrieved after a baseline correction, is shown in Fig. 3(b), where each point is the result of averaging the values obtained from all traces. The transmission curve is satisfactorily fitted by a Voigt profile, and the theoretical phase is subsequently derived from the fitted amplitude using the Kramers-Kronig relations. The root mean square (rms) of the residuals between the experimental transmission curve and the Voigt profile is σ=0.8 % at the noise level. In the low absorption regime, this value sets a limit on the absorbance αL that can be measured for an acquisition time of 500 µs. From σ, one can estimate the noise-equivalent absorption sensitivity (NEAS), defined as NEAS=σ/(L BW), where BW is the detection bandwidth [41]. For our self-heterodyne spectrometer, BW = 8 GHz and then NEAS =1.6×10−8 cm−1 Hz−1/2 (500 µs time-averaging). Assuming that σ scales as the inverse of the root-square of the acquisition time, the value of the NEAS for 1-s time averaging would be comparable to the one reported in [19].
4.1 Experimental setup
Practically, self-heterodyne interferometry is limited by the fact that the bandwidth of the detection chain must match the optical bandwidth of the FC. This requirement can be circumvented using dual-comb interferometry, which enables to perform multi-heterodyne spectroscopy with a much narrower detection bandwidth [4, 42]. Instead of making a probe comb (with a line spacing fp) interfere with a single frequency laser, a second comb with a slightly different line spacing (fLO=fp+δf) is used as a LO [see Fig. 4(a)]. The two combs are mixed in a photodetector and the application of a low-pass filter on the photocurrent provides beat notes between every line of the probe comb and the closest line of the LO. The resulting spectrum is an RF comb, with a line spacing of δf, which is orders of magnitude lower than fp, (δf≪fp). This frequency down-conversion is characterized by a compression factor defined as: C=fp/δf≫1. The frequency response of a sample, encoded on the lines of the probe comb, can be thus measured using a signal with a RF bandwidth: BW=BWopt/C, where BWopt is the optical bandwidth of the probe comb (i.e. the number of comb lines multiplied by the line spacing). The minimum time required to perform a complete measurement (i.e., the duration of an interferogram) is τ0=1/δf. In practice, the acquisition time τacq is usually much longer than τ0, in order to increase the signal-to-noise ratio [42].
Fig. 4 (a) Sketch of the optical setup used to perform dual-comb spectroscopy. RFA: RF amplifier; LPF: low-pass filter. Lower inset: RF spectrum obtained by directly mixing the output of the two FSLs with and without the stabilization loop (blue and red spectra, respectively). A zoom-in view of a single line is also included. The PID regulator allows obtaining around 240 lines within 10 dB. (b) Transmission and phase corresponding to the 11th line of the HCN P-branch. In the transmission curve, the red line is the Voigt profile that fits the experimental data (in blue) and the green squares plotted below are the corresponding residuals. In the phase plot, the red curve corresponds to the theoretical function derived from the Voigt profile.
A critical point for resolving each line of the RF spectrum is to ensure a high degree of mutual coherence between the combs. Similarly to electro-optic dual-comb spectrometers, in acousto-optic frequency combs, both FSLs are seeded by the same CW laser, a configuration much simpler than the one involving two stabilized frequency combs. However, when the acquisition time becomes too long (in order to average thousands of interferograms), small perturbations of the relative optical path length between the two FSLs (due, for instance, to mechanical vibrations or thermal drifts) limit drastically the bandwidth of the RF spectrum. This limitation is discussed in the conclusion paragraph. To overcome this restriction and provide a mutual stabilization of the two FSLs, we implement a low-bandwidth control loop [in green in Fig. 4(a)]. An error signal is generated by mixing one line of the RF spectrum (25th line), obtained from the beating of the probe comb with the LO, with a sine wave provided by an external function generator at the same frequency. This generator is locked to the clock that drives the acousto-optic shifters in the FSLs (system clock). The error signal is amplified and low-pass filtered (cutoff frequency at 300 Hz), before being sent to the PID (proportional-integral-derivative) controller. Then, the signal generated by the PID controller is applied to an electro-optic phase modulator (PM) inserted in the probe FSL. The PM acts like a tunable delay line, which enables to cancel in real-time the relative length fluctuations of the two FSLs. To demonstrate the performance of the control loop, we use a simplified version of the setup shown in Fig. 4(a), where the output of the probe comb directly interferes with the output of the LO comb. The offset between the two combs is 50 kHz (C = 1600 and both FSLs are fed by the laser used in Sec. 2 (1550 nm). The lower inset in Fig. 4(a) shows the Fourier transform of a 50-ms trace (containing 2500 interferograms) with and without the PID regulation (respectively blue and red spectra). A zoom-in view around the line 180 is also included to evidence the effect of the PID regulator. In practice, the stabilization scheme enables to use about 240 mutually coherent lines, with relative intensity variations lower than 10 dB, within 50 ms.
4.2 Molecular spectroscopy results
To prove the capability of acousto-optic FCs for dual-comb spectroscopy, we provide an experimental measurement of the P11 HCN absorption line. The experimental setup is shown in Fig. 4(a). To this end, we insert the HCN cell in one arm of the interferometer. The light source that feeds the two comb generators is the tunable laser employed in Sec. 3.2. The offset between the two combs is: δf=60 kHz and the compression factor is around 1300. A fiber pigtailed optical switch is inserted in the probe arm, to take a reference measurement, in such a way that every trace registered by the oscilloscope contains at least a pair of consecutive temporal signals, respectively recorded with and without the gas cell. In our experiments, the total duration of each recorded trace is 200 ms, from which two 50 ms long signals are extracted (one corresponding to the gas cell and the other one to the reference). Figure 4(b) shows the retrieved complex response corresponding to the P11 line, after applying a baseline correction algorithm, which removes the systematic variations between the signal measured with the cell and the reference. The blue points are obtained by averaging 20 independent traces. These results are very similar to those attained by means of self-heterodyne spectroscopy. A theoretical transmission Voigt profile and the theoretical phase derived by the Kramers-Kronig equations are also included in Fig. 4(b). The error in the transmission curve is σ=0.4 % at the noise level, leading to a NEAS at 1s time-averaging of 3×10−7 cm−1 Hz−1/2, a value somewhat lower than the one reported in [33].
We have demonstrated a new and versatile source of optical FCs, based on repetitive frequency shifts of a single-frequency laser in a FSL. This technique provides a flat optical comb composed of >1500 lines (within 10 dB). The line spacing is easily reconfigurable and ranges from tens of MHz down to the sub-MHz range. In a first implementation, the FSL included a pair of acousto-optic modulators inducing frequency shifts with opposite signs. Using this configuration, we have been able to record, by self-heterodyne interferometry, the transmission function of a Fabry-Pérot cavity with a spectral resolution of hundreds of kHz. When only a single acousto-optic modulator is inserted in the FSL, the comb bandwidth can be extended well beyond the GHz range. Using again a self-heterodyne technique and a fast detection chain, we have measured an absorption line of HCN at 1550 nm, covering an optical bandwidth of 8 GHz. This measurement has been carried out on the sub-millisecond time scale, a speed that makes unnecessary the use of control loops to stabilize the fiber interferometer. In order to eliminate the need for a large-bandwidth detection chain, we have implemented a multi-heterodyne interferometer with a pair of frequency combs generated in two different FSLs. This dual-comb scheme has provided a down-conversion factor larger than 1000 by setting a frequency offset between the combs of tens of kHz. To ensure the mutual coherence of the two combs on the measurement time scale, a PID control loop has been employed to compensate for the fluctuations in the relative optical path length between the two combs. This setup has been used successfully for the measurement of a HCN absorption line.
In conclusion, we have proven experimentally the capability of acousto-optic FCs to perform multi-heterodyne spectroscopy in different interferometric configurations. This comb modality presents many advantages. Similarly to combs generated by electro-optic modulation, the absolute comb frequencies are set by the frequency of the CW laser and the comb spacing is not linked to the length of a cavity. Moreover, a pair of mutually coherent FCs can be generated from the same CW laser. Finally, unlike previous approaches that involve non-linear optics phenomena or fast electronics to broaden the spectra, our approach permits the generation of combs with > 1000 coherent lines, and this without adding to the system hardware and/or software complexity. The high spectral resolution of acousto-optic FCs (sub-MHz), combined with the large number of spectral lines, makes them suitable for optical fiber sensing [29] or real-time atomic spectroscopy [30].
Contrary to electro-optic FCs, where all spectral lines are produced simultaneously in the electro-optic modulator, the different frequencies of the acousto-optic FCs are created by successive frequency shifts in a recirculating loop. Therefore, in order to perform coherent self-heterodyne interferometry, the coherence time of the seed laser must exceed the loop round-trip time multiplied by the total number of lines. Considering a FSL round-trip time of 100 ns and a number of lines of N = 1000, this condition requires to seed the FSL with a CW laser having a coherence time longer than 100 µs (i.e. a linewidth below 10 kHz). This condition is much less stringent in dual-comb interferometry: in that technique what matters is the mutual coherence between the consecutive pairs of lines generated by the two combs, which is easily satisfied if the two FSLs have comparable lengths. Apart from the requirements on the laser linewidth, in standard experimental conditions FSLs undergo mechanical disturbances arising from vibrations and thermal drifts. In general, the frequencies of mechanical noise are below 10 kHz, which means that, with the above parameters, the loop can be considered to be fixed on the time scale of N roundtrips. However, if the acquisition time exceeds by far this time scale, random fluctuations of the FSL length result in fluctuations of the comb spectral phase, and thus in a broadening of the comb lines. In this case, locking the length of the FSLs by means of a control loop is required, as in the dual-comb technique reported above. Notice that software-based and adaptive phase correction algorithms could also be employed in order to increase the number of useable lines, as well as to accumulate a high number of interferograms to perform coherent averaging [43,44]. Finally, the ultimate performance of acousto-optics FCs is linked to the maximum number of lines that can be created in a FSL. Here, we have reported the generation of more than 1500 mutually coherent lines. It turns out that this number depends critically on parameters such as the power of the seed laser, the gain and the noise factor of the EDFA, and the passive losses of the FSL [40]. An extensive investigation of the influence of these parameters, and the effects of gain saturation on the number of lines, will be published shortly.
Agence Nationale de la Recherche (ANR-14-CE32-0022).
We acknowledge support from the Agence Nationale de la Recherche (grant #ANR-14-CE32-0022). We also thank Tektronix France for the loan of a 25 GHz-bandwidth real-time digital oscilloscope.
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31. S. Wang, X. Fan, B. Xu, and Z. He, "Dense electro-optic frequency comb generated by two-stage modulation for dual-comb spectroscopy," Opt. Lett. 42(19), 3984–3987 (2017). [CrossRef] [PubMed]
32. B. Jerez, P. Martín-Mateos, E. Prior, C. de Dios, and P. Acedo, "Gain-switching injection-locked dual optical frequency combs: characterization and optimization," Opt. Lett. 41(18), 4293–4296 (2016). [CrossRef] [PubMed]
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J. Ye and S. T. Cundiff, eds., Femtosecond Optical Frequency Comb: Principle, Operation, and Applications (Springer, 2005).
D. J. Jones, S. A. Diddams, J. K. Ranka, A. Stentz, R. S. Windeler, J. L. Hall, and S. T. Cundiff, "Carrier-Envelope Phase Control of Femtosecond Mode-Locked Lasers and Direct Optical Frequency Synthesis," Science 288(5466), 635–640 (2000).
T. Udem, R. Holzwarth, and T. W. Hänsch, "Optical frequency metrology," Nature 416(6877), 233–237 (2002).
I. Coddington, W. C. Swann, and N. R. Newbury, "Coherent multiheterodyne spectroscopy using stabilized optical frequency combs," Phys. Rev. Lett. 100(1), 013902 (2008).
T. Ideguchi, S. Holzner, B. Bernhardt, G. Guelachvili, N. Picqué, and T. W. Hänsch, "Coherent Raman spectro-imaging with laser frequency combs," Nature 502(7471), 355–358 (2013).
I. Coddington, W. C. Swann, L. Nenadovic, and N. R. Newbury, "Rapid and precise absolute distance measurements at long range," Nat. Photonics 3(6), 351–356 (2009).
C.-H. Li, A. J. Benedick, P. Fendel, A. G. Glenday, F. X. Kärtner, D. F. Phillips, D. Sasselov, A. Szentgyorgyi, and R. L. Walsworth, "A laser frequency comb that enables radial velocity measurements with a precision of 1 cm s-1.," Nature 452(7187), 610–612 (2008).
T. Ohara, H. Takara, T. Yamamoto, H. Masuda, T. Morioka, M. Abe, and H. Takahashi, "Over-1000-Channel Ultradense WDM Transmission with Supercontinuum Multucarrier Source," J. Lightwave Technol. 24(6), 2311–2317 (2006).
T. J. Kippenberg, R. Holzwarth, and S. A. Diddams, "Microresonator-Based Optical Frequency Combs," Science 332(6029), 555–559 (2011).
M.-G. Suh and K. Vahala, "Gigahertz-repetition-rate soliton microcombs," Optica 5(1), 65–66 (2018).
P. Del'Haye, A. Coillet, T. Fortier, K. Beha, D. C. Cole, K. Y. Yang, H. Lee, K. J. Vahala, S. B. Papp, and S. A. Diddams, "Phase-coherent microwave-to-optical link with a self-referenced microcomb," Nat. Photonics 10(8), 516–520 (2016).
W. Liang, D. Eliyahu, V. S. Ilchenko, A. A. Savchenkov, A. B. Matsko, D. Seidel, and L. Maleki, "High spectral purity Kerr frequency comb radio frequency photonic oscillator," Nat. Commun. 6(1), 7957 (2015).
M.-G. Suh, Q.-F. Yang, K. Y. Yang, X. Yi, and K. J. Vahala, "Microresonator soliton dual-comb spectroscopy," Science 354(6312), 600–603 (2016).
P. Marin-Palomo, J. N. Kemal, M. Karpov, A. Kordts, J. Pfeifle, M. H. P. Pfeiffer, P. Trocha, S. Wolf, V. Brasch, M. H. Anderson, R. Rosenberger, K. Vijayan, W. Freude, T. J. Kippenberg, and C. Koos, "Microresonator-based solitons for massively parallel coherent optical communications," Nature 546(7657), 274–279 (2017).
A. Fülöp, M. Mazur, A. Lorences-Riesgo, T. A. Eriksson, P.-H. Wang, Y. Xuan, D. E. Leaird, M. Qi, P. A. Andrekson, A. M. Weiner, and V. Torres-Company, "Long-haul coherent communications using microresonator-based frequency combs," Opt. Express 25(22), 26678–26688 (2017).
V. Torres-Company and A. M. Weiner, "Optical frequency comb technology for ultra-broadband radio- frequency photonics," Laser Photonics Rev. 8(3), 368–393 (2014).
D. A. Long, A. J. Fleisher, K. O. Douglass, S. E. Maxwell, K. Bielska, J. T. Hodges, and D. F. Plusquellic, "Multiheterodyne spectroscopy with optical frequency combs generated from a continuous-wave laser," Opt. Lett. 39(9), 2688–2690 (2014).
P. Martín-Mateos, B. Jerez, and P. Acedo, "Dual electro-optic optical frequency combs for multiheterodyne molecular dispersion spectroscopy," Opt. Express 23(16), 21149–21158 (2015).
G. Millot, S. Pitois, M. Yan, T. Hovannysyan, A. Bendahmane, T. W. Hänsch, and N. Picqué, "Frequency-agile dual-comb spectroscopy," Nat. Photonics 10(1), 27–30 (2016).
F. Ferdous, D. E. Leaird, C.-B. Huang, and A. M. Weiner, "Dual-comb electric-field cross-correlation technique for optical arbitrary waveform characterization," Opt. Lett. 34(24), 3875–3877 (2009).
V. Durán, S. Tainta, and V. Torres-Company, "Ultrafast electrooptic dual-comb interferometry," Opt. Express 23(23), 30557–30569 (2015).
R. Yang, F. Pollinger, K. Meiners-Hagen, J. Tan, and H. Bosse, "Heterodyne multi-wavelength absolute interferometry based on a cavity-enhanced electro-optic frequency comb pair," Opt. Lett. 39(20), 5834–5837 (2014).
S. Boudreau and J. Genest, "Range-resolved vibrometry using a frequency comb in the OSCAT configuration," Opt. Express 22(7), 8101–8113 (2014).
E. L. Teleanu, V. Durán, and V. Torres-Company, "Electro-optic dual-comb interferometer for high-speed vibrometry," Opt. Express 25(14), 16427–16436 (2017).
V. Durán, P. A. Andrekson, and V. Torres-Company, "Electro-optic dual-comb interferometry over 40 nm bandwidth," Opt. Lett. 41(18), 4190–4193 (2016).
K. Beha, D. C. Cole, P. Del'Haye, A. Coillet, S. A. Diddams, and S. B. Papp, "Electronic synthesis of light," Optica 4(4), 406–411 (2017).
A. J. Fleisher, D. A. Long, Z. D. Reed, J. T. Hodges, and D. F. Plusquellic, "Coherent cavity-enhanced dual-comb spectroscopy," Opt. Express 24(10), 10424–10434 (2016).
N. B. Hébert, V. Michaud-Belleau, J. D. Anstie, J.-D. Deschênes, A. N. Luiten, and J. Genest, "Self-heterodyne interference spectroscopy using a comb generated by pseudo-random modulation," Opt. Express 23(21), 27806–27818 (2015).
X. Yan, X. Zou, W. Pan, L. Yan, and J. Azaña, "Fully digital programmable optical frequency comb generation and application," Opt. Lett. 43(2), 283–286 (2018).
N. B. Hébert, V. Michaud-Belleau, C. Perella, G-W. Truog, J. D. Anstie, T. M. Stace, J. Genest, and A. N. Luiteu, "Real-Time Dynamic Atomic Spectroscopy Using Electro-Optic Frequency Combs," Phys. Rev. Appl. 6(4), 044012 (2016).
S. Wang, X. Fan, B. Xu, and Z. He, "Dense electro-optic frequency comb generated by two-stage modulation for dual-comb spectroscopy," Opt. Lett. 42(19), 3984–3987 (2017).
B. Jerez, P. Martín-Mateos, E. Prior, C. de Dios, and P. Acedo, "Gain-switching injection-locked dual optical frequency combs: characterization and optimization," Opt. Lett. 41(18), 4293–4296 (2016).
B. Jerez, P. Martín-Mateos, E. Prior, C. de Dios, and P. Acedo, "Dual optical frequency comb architecture with capabilities from visible to mid-infrared," Opt. Express 24(13), 14986–14994 (2016).
J. Zhang, J. Yu, Z. Dong, Y. Shao, and N. Chi, "Generation of full C-band coherent and frequency-lock multi-carriers by using recirculating frequency shifter loops based on phase modulator with external injection," Opt. Express 19(27), 26370–26381 (2011).
H. Guillet de Chatellus, O. Jacquin, O. Hugon, W. Glastre, E. Lacot, and J. Marklof, "Generation of ultrahigh and tunable repetition rates in CW injection-seeded frequency-shifted feedback lasers," Opt. Express 21(13), 15065–15074 (2013).
H. Guillet De Chatellus, E. Lacot, W. Glastre, O. Jacquin, and O. Hugon, "Theory of Talbot lasers," Phys. Rev. A 88(3), 033828 (2013).
H. Guillet de Chatellus, L. R. Cortés, and J. Azaña, "Optical real-time Fourier transformation with kilohertz resolutions," Optica 3(1), 1–7 (2016).
C. Schnébelin and H. Guillet de Chatellus, "Agile photonic fractional Fourier transformation of optical and RF signals," Optica 4(8), 907–910 (2017).
H. Guillet de Chatellus, L. Romero Cortes, M. Burla, C. Schnébelin, and J. Azaña, "Agile photonic generation of arbitrary RF chirped waveforms," in Conference on Lasers and Electro-Optics, OSA Technical Digest (online) (Optical Society of America, 2017), paper SF2L.3.
H. Tu, L. Xi, X. Zhang, X. Zhang, J. Lin, and W. Meng, "Analysis of the performance of optical frequency comb based on recirculating frequency shifter influenced by an Er-doped fiber amplifier," Photon. Res. 1(2), 88–91 (2013).
E. J. Moyer, D. S. Sayres, G. S. Engel, J. M. St Clair, F. N. Keutsch, N. T. Allen, J. H. Kroll, and J. G. Anderson, "Design considerations in high-sensitivity off-axis integrated cavity output spectroscopy," Appl. Phys. B 92, 467–474 (2008).
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Acedo, P.
Allen, N. T.
Anderson, J. G.
Anderson, M. H.
Andrekson, P. A.
Anstie, J. D.
Beha, K.
Bendahmane, A.
Benedick, A. J.
Bernhardt, B.
Bielska, K.
Bosse, H.
Boudreau, S.
Brasch, V.
Chi, N.
Coddington, I.
Coillet, A.
Cole, D. C.
Cortés, L. R.
Cundiff, S. T.
de Dios, C.
Del'Haye, P.
Deschênes, J.-D.
Diddams, S. A.
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Fleisher, A. J.
Fortier, T.
Freude, W.
Fülöp, A.
Genest, J.
Glastre, W.
Glenday, A. G.
Guay, P.
Guelachvili, G.
Guillet de Chatellus, H.
Hall, J. L.
Hänsch, T. W.
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Hébert, N. B.
Hodges, J. T.
Holzner, S.
Holzwarth, R.
Hovannysyan, T.
Huang, C.-B.
Hugon, O.
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Pediatric Transplant
Starzl Institute
Kidney/Pancreas
Intestinal Transplant
Kidney and Pancreas Transplant
Who is a Candidate? Video Series Transplant Process Living-Donor Liver Transplant Your Transplant Team Patient Stories Contact Us
Susan Sher: Liver Transplant Patient Story
The Challenge: Primary Biliary Cirrhosis
In 1980, Susan Sher made a fateful deal with her husband, Dr. Stephan Sher. Concerned about his health, she told him that if he went for a complete physical, she would as well.
Although Stephan was fine, doctors discovered that Susan had a life-threatening condition.
"I was put in the hospital and they did a liver biopsy. They diagnosed me with primary biliary cirrhosis," Susan remembers.
Primary biliary cirrhosis is an autoimmune disease in which the immune system attacks bile ducts in the liver. As the ducts become damaged over time, bile builds up in the liver, eventually causing it to fail.
"There's no treatment," says Susan. "You get very itchy. You can go out of your mind with the itchiness. You turn yellow because your body can't get rid of the bile. I was diagnosed when I was 43 years old. It's a horrible disease. The ammonia levels in your brain get high, and I was not myself at all. The hepatologist said I was going to die."
The Path to UPMC: Meeting Dr. Starzl
Desperate, Susan's husband began to do some research on options.
"A little girl in New Jersey had just had a liver transplant. Dr. Starzl, who had performed it, happened to be coming to Allentown to give a talk. My husband went to hear him. We had nothing to lose."
Susan's hepatologist, however, was dubious of the idea of liver transplants.
"It was so new that my doctor said it was just grandstanding. Thank goodness for Stephan. If he weren't a doctor, I would not be alive today."
With the help of Thelma Thiel, founder of the American Liver Foundation, Stephan was invited to Washington, D.C. to meet with Surgeon General C. Everett Koop, Dr. Starzl, and others.
He was invited as a family physician, as well as the spouse of someone with end stage liver disease. It was March of 1982. At that time, Stephan had an opportunity to speak with Dr. Starzl, who arranged for Susan to come to Pittsburgh for a work up.
The Solution: "Your Typical Garden-variety Transplant"
After testing, doctors at UPMC felt that Susan needed a liver transplant.
"In June, they offered me a liver," she says. "I wasn't ready psychologically, and I refused it. Then I got scared. I thought they might not offer again."
In the next months, Susan's health grew progressively worse.
"By September, I weighed 95 pounds, my stomach was distended, and my skin was yellow."
She and her husband called Starzl, who said to come to Pittsburgh, and he would have a liver in a week.
That's exactly how long Susan waited in the hospital.
"Then, all of a sudden, they started prepping me for surgery. I was so ecstatic, I literally jumped onto the table."
The surgery lasted 12 hours. Susan's husband, children, and brother-in-law were there when she woke up.
"The yellow was gone. I wasn't itchy. All the poison had come out of me. It was absolutely amazing. I felt like my new liver was doing exactly what it was supposed to do."
Susan was in the hospital for four weeks. A few days after her surgery, Dr. Starzl looked at her daily blood test and casually remarked, "just your typical garden-variety transplant."
And Susan knew she was going to be all right.
She was given cyclosporine, an antirejection drug that was still experimental at the time. Then she and her husband went home to Allentown.
Of course, Susan traveled back to Pittsburgh regularly for medication adjustments and liver biopsies.
But a highlight of her transplant experience came in 1983.
"The day cyclosporine was approved, I was on The Today Show with Dr. Starzl and Dr. Borel, who discovered cyclosporine. It was interesting. It struck me that I was there with the two men who saved my life."
The Results: Enjoying Family and Retirement
After her transplant, Susan's life got back to normal very quickly. In a few weeks, she returned to her job as an office manager in her husband's practice.
Today, Susan has lived to see her daughter get married and have children, and to see her son become a doctor and a father, as well.
"Now I'm retired. I read a lot. I walk a lot. My husband and I enjoy being with each other. I'm still very happy to be alive."
She also keeps in touch with the people who changed her life.
"I write to Dr. Starzl every year on the anniversary of my transplant. He always writes back. I also write to the doctor who took care of me medically, and to my transplant coordinator, Sandra Stachak-Chico, who's now in charge of development at the Starzl Transplant Institute."
Susan muses, "I used to think if I could only have one normal day, I'd be happy. Now it's been 28 years."
Susan's treatment and results may not be representative of all similar cases.
Learn More About Liver Transplant
UPMC Health Library:
UPMC Liver Cancer Center:
Conditions We Treat at the Liver Cancer Center
History and Experience
Immunosuppressant Drugs
Pediatric Transplantation


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A concert of Baroque Music from Wellington based Early Music group, The Night Watch. Love Me Tender is a concert that reflects on the many facets of love and loss and will featuring the joint forces of four of Baroque Voices' finest singers, along with a collection of early instrument musicians from both Wellington and Sydney.
Featuring the vocal opulence of Pepe Becker, Katherine Hodge, Philip Collins, Will King and the instrumental exploits of Kamala Bain, Theo Small, Cat Macintosh, Annie Gard, Thea Turnbull, George Wills, Douglas Mews, Robert Oliver and Imogen Granwal, this concert will present some of the most loved Baroque repertoire including Bach's gorgeous BVW 106 and the heart thumping 'La Notte' flute concerto by Vivaldi. Hear the wonderful Telemann flute and recorder concerto and the lesser known exquisite Buxtehude cantata 'Wo soll ich fliehen hin' and be entertained by some effusive Handel.
You can choose from 2 concerts - February 9th at 6pm in Greytown, and February 10th at 4pm in Wellington. Tickets are available online for a reduced price, or at the door on the day (cash only). There is also a group special available - buy 6 tickets at one time either online or at the door, and get an additional ticket free. (6 adult tickets entitle you to one free adult ticket, and 6 student or student/adult tickets entitle you to one free student ticket).
Note: credit card fee applies to tickets purchased on Eventfinda.


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Tanzania Travel Tours
Lake Manyara National Park & Ngorongoro crater & Serengeti National Park
Moshi Tanzania Travel Tours
5 days safari
During this 5-day camping safari you will visit the Lake Manyara National Park, the Ngorongoro Conservation Area and the Serengeti National Park. The Serengeti is Africa's most famous park. Renowned for its incredible concentrations of predators and the Great Migration of two million wildebeest, the Serengeti guarantees an exceptional safari. The endless grassy plains (Serengeti in Maasai) are the richest grazing grounds on the continent, and therefore home to the largest herds and the highest concentrations of predators on the planet.
Day 1: Lake Manyara National Park (Moshi to Lake Manyara National Park to Mto wa mbu).
Our professional tour guides will meet you at the hotel and briefing you about the tour. You will travel up to Lake Manyara where you will be able to see tree climbing lions which are the park's main attraction. Why these lions habitually climb trees is still up for debate but viewing a pride relaxing in an acacia tree is an incredible site. The park is also famous for its elephant, huge number of baboons and due to its varied landscape has an impressive range of other game including wildebeest, buffalo, hippo, flamingo, zebra, warthog, waterbuck, dik-dik and impala. This small park is also home to over 400 species of birds, including flamingos, pelicans, storks and cormorants.
You will be able to view the surroundings as the safari vehicle's roof can open up to allow you the best angle for photography. After an extensive game drive in the park you will leave the park in the afternoon. Tonight you will spend the night under the stars as you camp at a campsite in the small town of Mto wa Mbu.
Day 2: Serengeti National Park ( Mto wa mbu to Serengeti National Park).
In the morning our after getting a breakfast and relax for a bit, a journey to Serengeti National Park will begin. Serengeti is one of those very rare places that has a huge reputation, yet still somehow manages to surpass expectations and take your breath away. Surrounded by remarkable tribes such as the Masai and Hadzabe, this wider area is also fascinating from a cultural perspective. In a nutshell, the Serengeti is the mother of all safari parks and the most celebrated wildlife reserve in the world.
Day 3: Serengeti National Park
In this day you will explore Serengeti National Park. Our tour guides will take you to see huge herds of wildebeest and zebra move in a clockwise direction around the vast plains, searching for fresh grazing grounds. Witnessing the migration in the Serengeti is really as good as it gets in terms of your Tanzania Safari. The Serengeti is one of the very few places in Africa where the game viewing is outstanding at any time of year. April and May see the heaviest rains but even then, the game viewing remains outstanding while the lodges are ridiculously good value and the park is quiet. We believe the very best times of year to be in the park are from January to March, when the herds of the Great Migration are calving, and from the middle of July all the way to the middle of November, when the herds are crossing the Mara river to or from Kenya.
Day 4: Ngorongoro crater (Serengeti National Park to Ngorongoro crater).
In this day you will have an opportunity of witnessing few wonders of Serengeti before heading to Ngorongoro crater. The world's largest intact volcanic caldera and home to the highest density of big game in Africa, including all the big five and plenty of predators. The Ngorongoro is justifiably one of the continent's most famous safari destinations.
Day 5: Ngorongoro crater. (Ngorongoro crater to Moshi).
Early in the morning you will have an opportunity to view different wild life. Today, the volcano is a Mecca for those looking to witness a whole host of animals and to take in "that" view. The crater floor itself, with its flat expanse and fertile soil, has become the year round home for many of Africa's largest animals such as the black rhino, black manned lion (the blacker the mane the older and more virile the lion) and the continent's densest population of spotted hyena….to name but a few. After half a day of extensive game viewing and a lunch at a picnic spot, you will leave the crater and travel back to Moshi.
1 Adult - 2 910.67€
2-3 Adults - 1 779.83€
6 or more adults - 1 032.50€


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Allegiant extends seasonal flights to the Hammock Coast area
For the folks in New York, Ohio, Kentucky, Indiana and Pennsylvania, a chance to get away for the perfect beach vacation on South Carolina's Hammock Coast just got a little easier — not only this summer but in the fall and winter, too.
Allegiant has extended its seasonal summer schedule to and from Myrtle Beach International Airport to include flights to select markets through Feb. 14, 2023. Those markets include Albany and Newburg in New York; Allentown, Pennsylvania; and Cincinnati, Ohio. In 2021, the airline began to expand its operation into shoulder-season months, with service to these destinations extended throughout the entire month of November, a first-ever for Allegiant at the Myrtle Beach International Airport, which serves the Hammock Coast.
Allegiant is expanding seasonal service times for four flights into Myrtle Beach International Airport, the closest major airport to the Hammock Coast.
Now the airline has expanded its service operations even more. In 2022 and 2023, travelers heading to and from these destinations will now have even more opportunity to enjoy time with family and friends for the entire holiday season.
Service to and from Albany International Airport (ALB) in New York will run from May 27, 2022, through Feb. 13, 2023
Service to and from from Lehigh Valley International Airport (ABE) in Hanover Township in Pennsylvania (serving the Allentown, Bethlehem and Easton Metropolitan areas) began on April 1, 2022, and will run through Feb. 13, 2023.
Service to and from Cincinnati/Northern Kentucky International Airport (CVG), located in Hebron, Kentucky, and serving the Tri-State areas of Kentucky, Ohio and Indiana, began on April 1, 2022, and will run through Feb. 12, 2023.
Service to and from New York Stewart International Airport (SWF), located in the Southern Hudson Valley, west of Newburgh, south of Kingston, and southwest of Poughkeepsie, approximately 60 miles north of Manhattan, New York City, will start on June 3, 2022, and will run through Feb. 12, 2023.
"Allegiant's continued schedule extensions at MYR speak volumes to the rapidly growing demand for travel in off-peak months," said MYR Director of Airports Scott Van Moppes. "Extreme passenger growth over the last several years has created untapped potential for flight availability during the fall and winter seasons at MYR and our airline partners have begun to take notice. We're thrilled to be able to offer Allegiant flights for a longer season in 2022 and are optimistic that this is a step in the right direction in increasing our year-round flight offerings."
Flights are available for purchase at www.allegiantair.com.
Myrtle Beach International Airport is the gateway to the Hammock Coast and the Grand Strand. MYR is served by Allegiant, American, Avelo, Delta, Frontier, Porter, Southwest, Spirit, Sun Country and United. It is considered one of the best airports in the United States and is the closest major airport to the Hammock Coast. With a growing number of passengers each year, the number of visitors flying to the Hammock Coast is also increasing. More than 3.2 million passengers came through MYR in 2021 — a record! Direct flights are available from larger cities, such as Atlanta, Boston, Charlotte, Chicago, Detroit, New York City, Philadelphia, Washington, D.C., and more. Ten airlines serve the airport, including Allegiant Air, American Airlines, Avelo, Delta Air Lines, Frontier Airlines, Porter Airlines, Spirit Airlines, Southwest Airlines, Sun Country Airlines, United Airlines, along with nine rental car brands.
The Hammock Coast is also served by Charleston International Airport (CHS), located in North Charleston, about 19 miles from the City of Charleston and about 75 miles from the Hammock Coast. The largest and busiest airport in South Carolina, Charleston International Airport sees more than five million passengers annually. Airlines serving the airport, including Alaska Airlines, Avelo, Delta Airlines, Delta Connection, JetBlue, American Eagle, United, United Express, and Southwest.
The publicly owned Georgetown County Airport (GGE), which can accommodate smaller planes and jets, also serves the Hammock Coast as the in-county airport, which is located at 129 Airport Road, south of the city of Georgetown, just outside the city limits on U.S. Highway 17. Nearly 150 flights are logged at the airport each day.
— By Mark A. Stevens, director of tourism development, Georgetown County Chamber of Commerce and South Carolina's Hammock Coast ®
Garden City, Georgetown, Hammock-All, Litchfield, Murrells Inlet, Pawleys Island
Georgetown Food, Beer and Wine Festival to make debut May 21 on the Hammock Coast
Gullah Geechee cultural interpreter Ron Daise pens new books


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Jenny Kwan: It's unfathomable for Hong Kong government to disregard such a powerful display of public opinion
by Jenny Kwan on June 13th, 2019 at 2:00 PM
Although I have left Hong Kong and immigrated to Canada when I was a young child, Hong Kong, as my place of birth, is much more meaningful to be than merely childhood memories. It is the birth place of my cultural heritage. As such, there will always be a connection to Hong Kong in my heart.
Watching recent events unfold in Hong Kong through the media, I was deeply inspired and moved by the democratic spirit of the one million Hong Kong people who took to the streets to partake in peaceful demonstrations to voice their concerns over the extradition bill.
However, my sense of optimism was quickly dashed, and instead devolved into despair and pain as the Hong Kong government responded to the protesters, first with disregard, then with violent suppression.
One million protesters! One million people is the combined population of Vancouver, Burnaby, and Richmond.
It is utterly unfathomable for a government with any accountability to the people it governs to disregard such a clear and powerful display of public opinion. It is even more unthinkable that such expressions would be imperiously suppressed.
The government's disregard of the protesters' point of view and its unilateral decision-making process has led to the escalation of the demonstrations and the violent confrontations that are now happening on the streets. There is no justification for a government to use such excessive force—tear gas and rubber bullets—against unarmed civilians in a peaceful demonstration.
When Hong Kong was returned to Chinese sovereignty, the "one country, two systems" constitutional principle was formulated due to the different economic, political, and legal system between the Hong Kong Special Administrative Region and the rest of China. This principle was enshrined in the Sino-British Joint Declaration. This was China's promise to the people of Hong Kong, the United Kingdom, and the world.
The people of Hong Kong are concerned that with the proposed amendments to its extradition laws, the "one country, two systems" principle would be broken, and the legal system of China could be exercised on people in Hong Kong through extradition to China. People from very diverse backgrounds, professions, and faiths have spoken out about their concerns with these possible changes. These concerns are valid and arose out of a genuine love for Hong Kong and democratic values.
The youth in Hong Kong are advocating for democracy, defending the Hong Kong judiciary's independence, and upholding the principle of "one country, two systems".
It breaks my heart to watch so many young people, passionate about the fate of their birthplace, confront fully armoured riot police, and get beaten down and injured.
It is my hope that the Hong Kong government will do the right thing before the needless violence further escalates.
It is my hope that the government of Hong Kong will restore peace and political stability to Hong Kong by respecting the wishes of the people and immediately withdraw the extradition bill.
Jenny Kwan is the NDP MP for Vancouver East and her party's critic for multiculturalism, immigration, refugees, and citizenship.
Jenny Kwan: It's time for Canada to finally acknowledge the horror of the Nanjing Massacre
Jenny Kwan: Commemorating the 30th anniversary of the Tiananmen Massacre
Author Joy Kogawa writes to Prime Minister Justin Trudeau seeking support for Nanjing Massacre Commemorative Day
NDP MP Jenny Kwan goes on Political Blind Date with Toronto-area Liberal MP Gary Anandasangaree
MP Jenny Kwan issues statement on imprisonment of Hong Kong Umbrella Movement leaders


A few random thoughts for this mid-week blog entry.
I'm looking forward to catching my first-ever Lilith Fair tomorrow night, but must admit I have several reservations. It's never a good sign when Sarah McLachlan, the tour headliner and organizer, admits that ticket sales have been "soft." Several dates were cancelled, and a quick glance at the temporarily unavailable TicketMaster instant seat locator showed that many of the remaining dates had vast sections of available seats. I don't know how to fix the sour ticket industry (eliminating "convenience" fees and lowering prices spring to mind, but I'm sure it's much more complicated), but I think Lilith hasn't done itself any favors. Many of these problems could be fixed by paying more attention to the Lilith Fair Website.
Fans should be able to see where each artists performs without having to click on every date. Clicking an artist's name brings up a highlighted list of her cities, but without dates. This is needlessly complex. Furthermore, the schedules for each city are missing. Eleven artists will play at Sandstone Amphitheater tomorrow night. Performances will start in the mid-afternoon. Approximate schedules should be posted weeks before each stop so fans will be able to make plans and adjust to be in place for their favorite performer. Each of these issues have easy solutions. Judging by the Website, it appears as if everyone threw in the towel long ago. These shows may be a loss, but fans still need to be cared for.
I have mellowed over time. Now when I hear Gaga's cover of "Imagine" I'm glad she has good taste and that someone is keeping Lennon's music alive, however the performance rates.
In another lifetime, in another era I would have been a great producer at Rhino Records. I love scouring the catalogs of artists, unearthing gems from dismissed albums or periods. Much of this ends up in multi-volume anthologies, but these treasures also work as nice garnishing in a playlist.
This leads me to Ringo Starr. Obsessive that I am, I created anthologies for all the fallow periods in the solo Beatle catalogs – except Ringo. The Fab drummer's 70th birthday last week caused me to reconsider this stance. So I dutifully investigated all of his albums. The critics weren't wrong – there's more bad than good. That said, there's always at least one keeper on each album, and if I hadn't been so dedicated I would have completely missed out on Ringo's first two fantastic albums.
Ringo's third solo album, 1973's "Ringo" soaks up all the love but "Sentimental Journey" and "Beaucoups of Blues" are just as good, albeit for very different reasons. Both albums came out in 1970, and both clock in around 35 minutes. Both the brevity and timing work in Ringo's favor. 1970 was both the best and worst year to be a Beatles fan. Sure the band broke up, but on the other hand fans got "Let It Be," "McCartney," "All Things Must Pass," "Plastic Ono Band" and the aforementioned Ringo platters.
Although they hit shelves only six months apart, "Sentimental Journey" and "Beaucoups of Blues" couldn't be more different. Both albums are genre exercises, but the big-band swing of "You Always Hurt the One You Love" is both geographically and generationally separated from the country twang of "Loser's Lounge." Yet Ringo's enthusiasm and personality shines through both project, making them an infectious and irresistible listen.
Neither album will replace "Abbey Road" or "A Hard Day's Night," but they easily trump "Red Rose Speedway," "Extra Texture" or "Some Time in New York City." Better yet, they can be found easily and cheaply on vinyl. Do yourself a favor and grab 'em next time you haunt the bins.
Wald recently took the time to speak with The Daily Record about some of the themes in his new book and, of course, how the Beatles changed rock and roll.
In the book you talk about how "everything old becomes new again," and use the Twist to illustrate your point. What are some of the other examples of cyclical trends you discovered?
To be fair, I don't say everything old can always be recycled. When something new comes along, we tend to look back and find things that seem similar to us. But I think that may be less a recognition of real cycles than a way of making the present seem less strange.
Why do you call "Rhapsody in Blue" the "Sgt. Pepper's" of the '20s?
This is really the germ of the whole book. I was reading how people in the people in the 1920s wrote about "Rhapsody in Blue" and noticed how similar it was to what was said about "Sgt. Pepper's" in the 1960s.
(In the 1920s) everyone was saying how until now jazz was a lot of noise and music for rowdies and kids, but now this had turned it into a mature art form. This is exactly what happened with "Sgt. Pepper's." Leonard Bernstein said he was excited about it and Lennon and McCartney were compared to Schubert. Just as "Rhapsody in Blue" created a respectable thing that could still be called "jazz," "Sgt. Pepper's" created something respectable that was still considered rock.
Who was Paul Whiteman and what was his impact on music? Why has he largely been forgotten today?
I spend a whole chapter in the book on this, but in a nutshell, Paul Whiteman was the most popular bandleader of the 1920s. He was the man who transformed the perception of jazz from noisy, small groups into large orchestras who played not only fun dance music, but also at Carnegie Hall.
I think Whiteman is largely forgotten because he didn't swing by and large and was resolutely white. We have understood the history of jazz to largely be a history of African-American music. Whiteman tried, for better or worse, to separate jazz from that heritage.
In many ways, the 1940s parallel today, in that there is fear new technology will usurp the traditional way artists got paid. Then it was a fear of jukeboxes and radio's reliance on pre-recorded music and today, of course, the dominant issue is digital piracy. What are some of the similarities and differences you've observed between these two decades?
The huge difference is that all the things we talked about in the '40s did involve musicians getting paid, just different musicians. It was R&B and country musicians getting paid instead of big bands. A lot of people previously neglected became huge stars.
What's happening now is really dangerous, in terms of musicians continuing to be able to make a living. It is exciting, in terms of everyone being able to make their music available to millions of listeners, but it is getting harder and harder to make a living in music. It's more like a lottery – win and become a star or lose and go on to something else.
There are skills you develop as a professional musician that we're seeing less and less of because people don't perform as much. Everyone in my book went through an apprenticeship playing seven nights a week for four or five hours a night. Those opportunities no longer exist. There's no way to build those kinds of skills today.
Explain the difference between hot and sweet combos. Why have the hot survived while the sweet are dismissed?
A lot of people will say this is a false dichotomy. Everyone played some sweet and some hot, but the best way to explain the difference to people of my generation is to go back to the British Invasion. In the U.S., we thought of both the Beatles and the Rolling Stones as belonging to the same genre. In England, however, the Beatles were called pop and the Rolling Stones were called R&B, and it's easy to understand why.
The way we look at it today, hot bands played for boys who were into music as fans and listeners, while sweet bands were for sappy girls. That's not the way I would phrase it, but it's not necessarily wrong. Women have always been the determining pop buyers, because they like to dance, but men have always been the main critics. In any case, in the 1930s the two extremes were Guy Lombardo on the sweet end and Count Basie as hot, but most bands were in the middle.
One reason the hot bands live on is because by and large the only people listening today are jazz fans and they always liked the hot bands better. There's also the racial component I mentioned earlier. I don't disagree that what is exciting in American music was largely taken from African-American music—I would argue that it's more complicated than that, because they are always interchanging, but as a listener I am certainly more excited by Basie than by Lombardo. As a historian, though, I am interested in both, and well aware that in their era Lombardo was far more popular.
What is the connection between swing and rock and roll?
It was the hot dance music, youthful, noisy dance music. We think of these worlds as separate, but a lot of the same musicians crossed over. The first house band for Alan Freed's rock party was the Count Basie Orchestra. Bill Haley and the Comets all did their apprenticeships playing swing. Musically, there was a lot of overlap.
How did the success of the Beatles and other late-'60s rock bands segregate the music industry? What are the lasting effects of that segregation?
Two things happened at once. One, the Beatles arrived when the industry was moving very heavily toward black music. The myth is the Beatles rescued us from Frankie Avalon, but they really rescued us from Motown and girl groups. If you look at the charts, black groups had so completely taken over, they actually stopped having separate charts.
The Beatles and British Invasion bands were exciting, but their rhythm sections were old fashioned. In a world of Motown and James Brown they played archaic styles. Black kids were not much interested in the British bands, because they weren't as much fun to dance to—and it was not just black kids, but everyone who was dancing to Motown, which included a lot of white kids, especially white girls.
At the same time, the discotheque craze was hitting, so people didn't have to have live bands. The lasting effect of that is that you no longer had to have one band who could play every style of music. Before you couldn't have a band play only black or white music, because people wanted to dance to and hear the full range of current hits. In the '60s, though, you could have one band only play one kind of music, because when you wanted to hear a different kind you could just change the record.
In the epilogue you discuss how rock and dance music gradually began playing to divergent audiences. Do you think they will intersect again?
Today we don't have bands that have to play anything, period. It's a sad reality that if you listen to hit records – or even records that aren't hits, by little-known, local performers – the number of records where the group on the album plays regularly is vanishingly small. The number of hits that can be recreated without recordings is virtually none.
Don't get me wrong; hip hop couldn't exist in a world where you had to play everything live and I think hip hop is exciting. Overall, however, the world of live music is becoming extinct. There are certainly plenty of people for whom live music is important, and I'm sure there always will be, but they are increasingly a minority.