Subcollinear acousto-optic tunable filter based on the medium with a strong acoustic anisotropy

Abstract

We design and investigate the properties of acousto-optical tunable filter (AOTF) based on tellurium dioxide (TeO2) single crystal. We use so-called "subcollinear" geometry of anisotropic acousto-optic interaction that occurs when the wavevector of incident light is collinear to acoustic energy vector. We have obtained the analytical formula of spectrum spread function of proposed AOTF and have found the condition determining the shape of that characteristic. Also we have designed and fabricated the experimental prototype of subcollinear AOTF. In our design we have used the reflection of acoustic wave that allowed to use crystal's media more effectively and reduce the AOTF size. The main advantage of filter based on proposed geometry is extremely low value of electrical driving power (20 mW) that makes it a strong candidate in many applications. (C) 2003 Elsevier Science B.V. All rights reserved.