Bit Error Rate Of Weak Optical Communications Based On Single Photon Detection

Free space optical communication in atmosphere laser communication because of the influence of atmospheric channel and bad environment,the light signal at the receiving end is often very weak,even reach the level of photons.So at first the atmosphere laser communication is only for short distance communication between and emergency communication means.But with the development of semiconductor technology,the level would be able to detect photons signals of the single photon detector.It can solve the problem of signal detection at the receiving end,thus people began studying communication performance of the single photon detector.Through analysis and simulation,this paper studies the bit error rate obtained by detecting NRZ-OOK,RZ-OOK and M-PPM signals under two modes of gated operation and free operation respectively.Starting from the detection technology of weak optical signal,this paper compares the merits and demerits of the communication index of different detection technologies,and leads to the research on the bit error rate of communication obtained by using single photon detector and its array to detect weak optical signal.This paper introduces the working principle,types and related parameters of the single photon detector,which provides the theoretical basis for the follow-up research on the communication bit error rate of the single photon detector.In this paper,we first study the bit error rate of a single photon detector and its array in gated mode.In the case of single-photon detector detection,based on the existing theory of bit error rate under NRZ-OOK modulation,the bit error rate under RZ-OOK and M-PPM modulation is discussed respectively.And the influence of the relationship between gate width time and signal cycle on bit error rate under RZ-OOK modulation is also discussed.In the case of single-photon detector array detection,on the basis of the existing theory of bit error rate under NRZ-OOK and M-PPM modulation,the bit error rate under RZ-OOK modulation is discussed.At the same time,when the array element number is 1,the analysis of bit error rate under OOK and M-PPM modulation under single-photon detector is verified to be correct.At last,we study the bit error rate of single photon detector and its array in the free running mode.On the basis of the existing theory of bit error rate under NRZ-OOK modulation,the bit error rate under RZ-OOK and M-PPM modulation is discusseddetector array detection,the bit error rate of RZ-OOK and M-PPM modulation is discussed based on the existing theory of bit error rate of NRZ-OOK and BPPM modulation.