Collinear acousto-optic diffraction based optoelectronic oscillator

Abstract

We present the results of an optoelectronic oscillator based on collinear acousto-optic (AO) filter characterization. The system includes hybrid feedback and operates above the self-excitation threshold. Thus, it does not require the RF generator to arouse ultrasound in the AO cell. The rise time and delay time dependencies on the optoelectronic feedback parameters were defined. It was found that by tuning the feedback gain it is possible to vary the system time characteristics in a fairly wide range. The examination of the feedback loop phase shift influence on the system operation made it possible to discover the existence of multistability, manifested in an abrupt change of the feedback loop RF signal frequency and, consequently, the optical radiation intensity at the AO cell output. The multistability existence was explained in terms of the phase balance condition.