Results 251 to 260 of about 127,186 (271)

Homodyne coherent optical receiver for intersatellite communication

Applied Optics, 2018
For increasing the data rate and reducing the power consumption in satellite communication systems, free-space optical communication technology has been verified as an attractive alternative to traditional radiofrequency communication systems. In this study, a high-sensitivity homodyne coherent optical receiver was demonstrated. A sensitivity of -59.2  
Chaolei, Yue, Jiawei, Li, Jianfeng, Sun, Ren, Zhu, Xia, Hou, Xiaoxi, Zhang, Lei, Liu, Weibiao, Chen   +7 more
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Coherent Optical Communication Systems

2011
The rapid evolution of long-haul optical communications systems, witnessed in the last five years, is due to the gradual adoption of spectrally efficient, multilevel modulation formats, in conjunction with polarization division multiplexing (PDM) and coherent intradyne detection assisted by digital signal processing (DSP).
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Coherent optical fiber communications

SPIE Proceedings, 1991
The very high detection sensitivities and selectivities associated with coherent lightwave techniques furnish a basis for the exploitation of the great potential bandwidth of single-mode fibers in point-to-point and point-to-multipoint transmission.
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Dispersion compensation in coherent fiber-optic communications

Optics Letters, 1987
Linear filtering techniques in coherent communications systems appear to offer a useful method for increasing the bandwidth in dispersion-limited fiber-optical signal propagation. These techniques are described, and the requirements on filter performance are outlined. Bandwidth is shown to be related to the square root of the filter figure of merit.
R G, Priest, T G, Giallorenzi
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Adaptive Optics for the Atmospheric Coherent Optical Communications

Imaging and Applied Optics 2015, 2015
We present the results that the mixing efficiency and the bit-error-rate of the atmospheric coherent optical communications improved by a real 127-actuators adaptive optics system operating on 1550nm wavelength on a 1.8m telescope.
Chao Liu, Mo Chen, Shanqiu Chen, Hao Xian, Changhui Rao   +4 more
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Coherent optical space communications

2006
This paper reviews the present state of concepts and technologies of coherent optical space communications. Emphasis is placed on the receiving segment. Heterodyne and homodyne reception allows to realize sensitivities close to the theoretical limits which amount to as little as 10 to 40 photons per bit.
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Coherent optical fiber communications system using all-optical correlation processing

Optics Letters, 1990
We propose a point-to-point or single-ended communications technique based on single-mode optical fibers that uses all-optical pulse multiplexing at the transmitter and coherent optical correlation at the receiver. This technique shows potential for application to secure untappable communications, fiber local-area networks, and optical ranging in the ...
D D, Sampson, D A, Jackson
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Electro-optic resonant modulator for coherent optical communication

SPIE Proceedings, 1991
A resonant cavity electro-optic phase modulator has been designed and implemented to operate at a data rate of 10 Mbps. The modulator consists of an electro-optic crystal located in a highly resonant cavity. The cavity is electro-optically switched on and off resonance, and the phase dispersion near the cavity resonance provides the output phase ...
Deborah L. Robinson, Chien-Chung Chen, Hamid Hemmati   +2 more
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Multichannel coherent optical communications systems

Journal of Lightwave Technology, 1987
Balanced coherent receivers perform substantially better than single-detector receivers in multichannel optical fiber FDM communications systems since the balanced approach eliminates the direct-detection and signal-cross-signal interference. The permissible channel spacing D depends on the intermediate frequency f IF , on the bit rate R b , and on the
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Coherent Optical Free-Space Communications

Optical Amplifiers and Their Applications/Coherent Optical Technologies and Applications, 2006
The performance of coherent FSO systems operating within atmospheric are limited by turbulence. The performance statistics are computed from models for the induce index fluctuations, the second order Rytov perturbation method of solution to the stochastic wave equation and an extended form of the Huygens-Fresnel.
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