Approximation Method for Calculation of Output Response Parameters of Acousto-Optic Demodulator on Pulsed Input Influence

In this paper, there are represented the features of acousto-optic interaction in the context of pulse signal detection. It specifies the necessity of the development of a simpler method for the calculation of a demodulator output signal parameters in case of its feeding with a pulse signal. Approximation models of modulating pulse and a pulse of the photodetector’s output were made based on geometric representation of the photo-elastic interaction. It is shown the main parameter defining the shape of the output pulse is the inertia of the acousto-optic demodulator. It is postulated that this parameter is shaped due to the influence of two factors: an acoustic-optic interaction and a photodetector inertia. For estimation of the degree of influence of these factors, a numerical analysis based on developed models is carried out. The results of theoretic research and numerical analysis are verified with experimental research. It is stated that for the application of a high-performance photodetector, the inertia of the acousto-optic demodulator is defined mainly by space-time parameters of acousto-optic interaction.