Effect of Atmospheric Turbulence Coherence Degradation on the Scintillation Index for a Partially Coherent Laser Beam

摘要

By using the theories of the mutual coherence function and the intensity scintillation of a laser beam propagating through turbulent atmosphere, the influence of light source partial coherence and the coherence degradation caused by turbulence on the scintillation index of a partially coherent laser beam are analyzed. The results show that atmospheric turbulence has a dual impact on the quality of a laser atmosphere communication channel. The intensity scintillation induced by turbulent atmosphere can increase the communication link bit error rate (BER), while the degeneration of coherence caused by atmospheric turbulence or adopting a partially coherent light source can decrease the BER within a certain distance range. Hence, the BER improvement by using a partially coherent laser as source may be restricted by turbulence coherence degradation for a laser atmosphere communication link.