Coherent laser communication system based on wavefront correction

Abstract

The present invention provides a coherent laser communication system based on wavefront correction. The device is composed of a polarizer (1), a telescope system (2), a beam splitter prism (3), a Hartmann-Shack wavefront sensor (4), a computer system (5), a wavefront controller (6), a spatial light modulator (7), a local oscillator laser (8), an optical coupler (9) and a detector (10). The telescope system (2) receives the laser which passes through the atmosphere. The Hartmann-Shack wavefront sensor (4) detects the deformed wavefrotn signal. The computer system (5) applies the Zernike polynomial for reconstructing the non-deformed wavefront signal. After the correction of spatial light modulator (7), the non-deformed wavefront signal is executed with frequency mixing with the light beam emitted from the local oscillator laser (8) for generating the coherent intermediate frequency signal and transmitting to the detector (10). The whole system corrects the laser which passes through the atmosphere through the above mode for causing that the detector (10) obtains the coherent laser signal after correcting the deformed wavefront signal.

Description

technical field [0001] The patent of the present invention relates to a coherent laser communication system based on wavefront correction. Background technique [0002] The concept of laser communication was first proposed in the 1960s, but due to the limitation of the technical level at that time, the research on laser communication has just started. It was not until the 1980s, with the development of optoelectronic technology and device technology, that the research on laser communication began to receive more and more attention. Laser communication systems are divided into coherent communication systems and non-coherent communication systems according to the receiving system. The early laser communication system borrowed from the technology of optical fiber communication and adopted a non-coherent communication system with direct detection, which can realize medium and low speed communication, but the transmission power and receiving sensitivity of the system are limited...

AI Technical Summary

Problems solved by technology

The transmission of laser in the atmosphere is affected by effects such as atmospheric turbulence, the wavefront phase is distorted, and the wavefront phase with the local oscillator laser does not meet the constant phase difference requirement, which reduces the heterodyne mixing efficiency of the signal light and the local oscillator signal light. Leading to a decrease in the signal-to-noise ratio of coherent optical communication and an increase in the bit error rate

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