Аnalysis of efficiency of accumulation of signals in optical receivers

It is considered that the longer signal accumulation in a plane of a phototarget of the optical receiver, the proportionally a bigger signal collects. In article it is shown that only at small durations accumulation there is a proportional growth of a signal on a receiver exit. At increase in time of accumulation even to typical durations can and not occur at all signal increases at a receiver exit that can sharply lower sensitivity of receivers.