Acousto-Optic Tunable Filters for Imaging Applications in the 2 4 μm with Low RF Drive Power

in the 2 4 μm with Low RF Drive Power S. Valle, J.D. Ward, C. Pannell, N.P. Johnson Gooch and Housego (UK) Ltd, Dowlish Ford, Ilminster, Somerset, TA19 0PF, UK Optoelectronics Group, School of Engineering, University of Glasgow, Glasgow G12 8LT, UK Gooch and Housego (Orlando), 4632 36th street, Orlando, Fl 32811, USA The λ dependence on acoustic eld intensity (and hence RF drive power) can render large aperture acoustooptic tunable lters impractical for many applications beyond about 2 μm. One potential technique for reducing the RF drive-power requirement is to con gure an acousto-optic tunable lter such that the interaction region is at acoustic resonance. We describe an acousto-optic tunable lter that operates at resonance and present an analysis of the predicted performance. In addition, we address the practical issues in deploying such a scheme. Finally, we present results of a prototype resonant acousto-optic tunable lter operating in the 1 2 μm region.