COHERENT DIGITAL OPTICAL SIGNAL TRANSMISSION LINE Russian patent published in 2000 - IPC

FIELD: quantum radio engineering and optical communications. SUBSTANCE: transmission line that may be found useful for fiber-optic equipment, laser space, aerial, and other communication systems has optical phase modulator, laser transmission generator, frequency control and laser beam narrowing device, two matching devices, optical signal transmission medium, local laser transmission generator, optical mixer, photodetector, two amplifiers, optimal filter, and resolver. Novelty is that known transmission line is provided, in addition, with adder, third amplifier, intermediate-frequency oscillator, power splitter, intermediate- frequency filter, synchronous detector, extreme signal level detector, signal zero level detector, threshold level detector, modulation canceling device, nonlinear component; all these newly introduced pieces of equipment enable automatic phase and frequency control of local laser generator without branching part of optical power off the transmitted signal for the purpose thereby reducing signal power across output of optical signal transmission medium at preset transmission error probability. As compared with closest analogs, energy potential of proposed line is higher by 4-9 dB which makes it possible to increase length of regeneration section of main, regional, and urban communication systems and networks. EFFECT: increased length of transmission line, reduced total cost of equipment. 3 dwg