1. Field of the Invention
The present invention relates to an interferometer that measures the amphat of a coherent or incoherent EM signal, including natural light. In principle, the amphat of any signal of any wavelength, incoherent or coherent, may be measured using this technique. In this way, the amphat of the signal may be stored and analyzed. The corresponding image may be reconstructed as well.
2. Description of the Prior Art
U.S. Pat. No. 5,875,030 describes a Method and Apparatus for Coherent Electromagnetic Field Imaging Through Fourier Transform Heterodyne. From the abstract: Apparatus and method for imaging objects through the inverse transformation of a set of Fourier coefficients measured by a detector. The Fourier coefficients are generated by heterodyning the electromagnetic field reflected from an object, with a reference electromagnetic field that has had the transverse phase modulated with a Fourier basis set. Doppler imaging of objects is accomplished through temporal frequency filtering of the Fourier coefficients at a plurality of heterodyne intermediate frequencies.
Fourier Transform Heterodyne (FTH) technology operates on coherent or quasi-coherent light only. As a coherent technique, it utilizes a laser or local oscillator as the second, coherent beam. Incoherent signals, including natural light signals, cannot be analyzed by FTH technology.
U.S. Pat. No. 7,271,418 B2 describes a Semiconductor Apparatus for White Light Generation and Amplification. From the abstract: The present invention is a semiconductor apparatus for white light generation and amplification, where, under different current bias, white light can be generated steadily and evenly by folding up multi-wavelength quantum wells and by side-injecting a current. And, the white light can be excited out electronically without mingling with a fluorescent powder so that the cost for sealing is reduced. Because the light is directly excited out by electricity to prevent from energy loss during fluorescence transformation, the light generation efficiency of the present invention is far greater than that of the traditional phosphorus mingled with light-emitting diode of white light. Besides, concerning the characteristics of the white light, the spectrum of the white light can be achieved by adjusting the structure and/or the number of the quantum wells while preventing from being limited by the atomic emission lines of the fluorescent powder.
The patent in the preceding paragraph does not include using the generated EM signal as a homodyne analyzing signal of an interferometer using quadrature phase analysis.
The publication, Energy-transfer pumping of semiconductor nanocrystals using an epitaxial quantum well, Achermann, M., et al, Nature, Vol 429, pg 642, describes light generation that is shifted from the stimulating radiation. From the abstract: As a result of quantum-confinement effects, the emission colour of semiconductor nanocrystals can be modified dramatically by simply changing their size1,2. Such spectral tunability, together with large photoluminescence quantum yields and high photostability, make nanocrystals attractive for use in a variety of light-emitting technologies—for example, displays, fluorescence tagging3, solid-state lighting and lasers4. An important limitation for such applications, however, is the difficulty of achieving electrical pumping, largely due to the presence of an insulating organic capping layer on the nanocrystals. Here, we describe an approach for indirect injection of electron-hole pairs (the electron-hole radiative recombination gives rise to light emission) into nanocrystals by non-contact, non-radiative energy transfer from a proximal quantum well that can in principle be pumped either electrically or optically. Our theoretical and experimental results indicate that this transfer is fast enough to compete with electron-hole recombination in the quantum well, and results in greater than 50 percent energy transfer efficiencies in the tested structures. Furthermore, the measured energy-transfer rates are sufficiently large to provide pumping in the stimulated emission regime, indicating the feasibility of nanocrystal-based optical amplifiers and lasers based on this approach.
The publication in the preceding paragraph does not include using the wavelength-shifted, generated EM signal as the analyzing signal of an interferometer.
The publication, Hybrid silicon evanescent wave laser fabricated with a silicon waveguide and III-V offset quantum wells, Hyundai, P., et al, OPTICS EXPRESS, Vol. 13, No. 23, discusses evanescent wave stimulation of quantum wells. From the abstract: A novel laser that utilizes a silicon waveguide bonded to AlGaInAs quantum wells is demonstrated. This wafer scale fabrication approach allows the optical waveguide to be defined by CMOS-compatible silicon processing while optical gain is provided by III-V materials. The AlGaInAs quantum well structure is bonded to the silicon wafer using low temperature oxygen plasma-assisted wafer bonding. The optically pumped 1538 nm laser has a pulsed threshold of 30 mW and an output power of 1.4 mW.
The publication in the preceding paragraph does not include using the radiation from the quantum wells as an analyzing signal of an interferometer.