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Heterodyne detection of enhanced backscatter
CLEO '97., Summaries of Papers Presented at the Conference on Lasers and Electro-Optics, 1997Heterodyne detection has been used to measure the enhanced backscattering from a standard target consisting of a plane mirror positioned behind a moving ground-glass disk (assumed to act as a phase screen). A tilt of the plane mirror in combination with spectral filtering of the detector output allows isolation of the double-scattered component of the ...
M, Pitter, E, Jakeman, M, Harris
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Current sensor using heterodyne detection
Applied Optics, 1999Based on the Faraday effect for measuring ac current, we describe a fiber-optic sensor that uses laser-diode intensity modulation to perform heterodyne signal detection. The sensor output at the carrier frequency is used as a reference signal to normalize the results.
J A, Ferrari +3 more
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Atmospheric laser heterodyne detection
Infrared Physics & Technology, 1996Abstract We describe in this paper what has been done for ten years at Reims in the area of atmospheric heterodyne laser spectrometry. The recent technical progress allows now to use this technique in two different ways. The first is devoted to the radiometry with low spectral resolution [0.1 cm −1 ] of “cold” gases (300 K) in the troposphere.
Delahaigue, Alain +4 more
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Nanoscale defect detection by heterodyne interferometry
Applied Optics, 2009We construct an instrument that facilitates the measurement of nanoscale defects. It is based on heterodyne interferometry with phase measurement that utilizes a polarizing beam splitter to form a measuring signal and an oscillating cantilever tip that acts as a scanning probe to get the measurement values of sample topography.
Haoshan, Lin +4 more
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Proceedings of the IEEE, 1968
Heterodyne experiments have been performed in the middle infrared region of the electromagnetic spectrum using the CO 2 laser as a radiation source. Theoretically optimum operation has been achieved at kHz heterodyne frequencies using photoconductive Ge:Cu detectors operated at 4°K, and at kHz and MHz frequencies using Pb 1-x Sn x Se photovoltaic ...
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Heterodyne experiments have been performed in the middle infrared region of the electromagnetic spectrum using the CO 2 laser as a radiation source. Theoretically optimum operation has been achieved at kHz heterodyne frequencies using photoconductive Ge:Cu detectors operated at 4°K, and at kHz and MHz frequencies using Pb 1-x Sn x Se photovoltaic ...
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Noise in homodyne and heterodyne detection
Optics Letters, 1983Quantum-mechanical calculations of the mean-square fluctuation spectra in optical homodyning and heterodyning are made for arbitrary input and local-oscillator quantum states. In addition to the unavoidable quantum fluctuations, it is shown that excess noise from the local oscillator always affects homodyning and, when it is broadband, also ...
H P, Yuen, V W, Chan
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Nonlinear heterodyne detection
1977Conventional heterodyne detection is useful in a number of configurations, including the detection of scattered or reflected radiation from a moving target (Doppler radar), communications, spectroscopy, and radiometry. Its use has been demonstrated in many regions of the electromagnetic spectrum including the radiowave, microwave, infrared, and optical.
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Heterodyne detection of blackbody radiation
Applied Physics Letters, 1973In order to extend to the infrared range some of the interferometric methods utilized in radioastronomy, the heterodyne detection of 10.6-m blackbody incoherent radiation has been accomplished, and the correlation between detected signals has been studied.
J. Gay +3 more
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IEEE Spectrum, 1968
Optical heterodyne detection presents some difficult problems, but for certain applications it offers considerable advantage over the more conventional detection methods. Some of these advantages and problems, and how they are affected by the transmission medium involved, are discussed in this article.
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Optical heterodyne detection presents some difficult problems, but for certain applications it offers considerable advantage over the more conventional detection methods. Some of these advantages and problems, and how they are affected by the transmission medium involved, are discussed in this article.
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Optical heterodyne (coherent) detection
American Journal of Physics, 1988The optical heterodyne principle is described and its history traced. Early hopes for optical communication by this technique were frustrated by problems of wavefront degradation and laser frequency instability. However, fiber optics has recently revitalized this as an attractive possibility. In the interim, many other successful applications have been
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