Based on the definition of Pegg-Barnett phase state, the phase probability distribution functions of generalized coherent states are analytically calculated. It is shown that the phase probability distribution curve is the poisson distribution and the peak value of the curve increases when the value of |β| increases.
This article,according to the Pegg-Barnett phase theory,infers the phase probability distribution function of the coherent condition light field,calculates the phase to fluctuate,and has carried on the value simulation using MATHEMATICA to the coherent condition light field phase function and the phase fluctuation,has drawn the schematic drawing.The result indicates at the same time the phase function is restricted by the e exponential function and the exponent sign function,from evenly distributes to the Poisson's distribution to the even distribution,until presents the zero distribution;In a phase change cycle,the coherent condition phase distribution curve appears the fluctuation,at the same time the fluctuation is referred the phase and the coherent coefficient influence,along with the n value increase,the curve tends to the Gaussian distribution.