Research on the influences of phase fluctuations on optical coherent detection systems

Aiming at the optical coherent detection systems placed in atmosphere, we analyze the effects of phase fluctuations caused by atmospheric turbulence and simulate the coherent efficiency at different turbulence intensity. At the receiver, we decompose the phase distortion which caused by turbulence and put low order mismatching parameters into the equation of coherent efficiency which is used to describe coherent performance. Coherent efficiency is sharply deteriorated with the turbulence intensity increasing. Under the same conditions, system employing long wavelength and optimizing the diameter of collection aperture can get high sensitivity. Adaptive optics can be used to improve coherent performance.