Invariance of probability characteristics of detector to shape of optical pulse signals

Four approximations of the description of the shape of optical signals at the receiving end of a laser system are analyzed: rectangular, sinusoidal, Rayleigh and normal. The parameters for the Rayleigh and normal approximations are based on 99.7% of the energy being concentrated in the interval O, T(1). A detector is analyzed in which the maximum value of the random process is extracted at the output of the photodetector in the observation interval and compared with a threshold. It is found that the probability characteristics of a detector for pulsed light signals depend upon the ratio of the signal and background radiation power, as well as their absolute values. The probability characteristics of the detector are determined by the useful optical radiant energy, and are independent of the form of the signal when the bandwidth of the receiving/amplifying channel is optimum. The bandwidth, depends upon the ratio of the power of the signal and background radiation.