In this paper

the correlation between quantum phase noise and field of single frequency semiconductor laser is investigated with the method of self-delayed heterodyne. The influence of quamtum phase noise on coherent detection system is discussed in terms of photocurrent auto correlative and power spectral functions. In general

photocurrent power spectrum consists of delta function and qnasi-Lorentzian shape portion

which is of great significance for the coherent measurement of semiconductor lasers.