Abstract

Single crystal quartz is one of the few usable materials for building acoustooptical tunable filters (AOTFs) which operate at wavelengths shorter than 300 nm. Unfortunately, in quartz the acoustooptic interaction coefficient is low. High power (of the order of tens of watts) is required for reasonable amounts of diffraction. If the AOTF is built so that the face opposite the acoustic transducer is parallel to the transducer, when the AOTF is operated with continuous rf excitation, the cell becomes a resonator for the acoustic energy. At resonance the power required for a given diffraction efficiency is reduced by a factor which can be as much as 20. I discuss the implications of resonance on AOTF operation and show data from quartz filters operating from 220 to 400 nm with <1 W of drive power required.

© 1988 Optical Society of America