Spectral and temporal behavior of a quasi-collinear AOTF in response to acoustic pulses: simulations and experiments

Abstract

This paper is dedicated to the study of an AOTF whose selectivity and side lobes are controlled thanks to acoustic square pulses with different and relatively low acoustic power. The behavior of the transmission function of a quasi-collinear acousto-optical tunable filter in TeO₂ is analyzed. The filter is used with acoustic pulses above 12 µs to manipulate the selectivity and with an electric power up to 600 mW to control the side lobes of the filtered spectrum. Using acoustic pulses requires working under a regime of a long optical pulse. The temporal response of the filter was considered to find the best parameters to perform the experiments. The selectivity was controlled from 1.3 nm to 2.5 nm with the use of acoustic pulses. The manipulation of the acoustic power applied to the filter improved the performance of the side lobe levels in regards to the main one from -9dB to -12dB.