Abstract

The acousto-optic tunable filter (AOTF) is an all-solid-state, electronically tuned optical filter that operates on the principle of acousto-optic diffraction in an anisotropic medium. The basic theory of the AOTF and its various applications have been extensively reported.¹ Most of the previous studies have been directed at nonimaging systems. Recently, there has been considerable interest in using AOTF in a spectropolarimeter for remote sensing of earth and planetary resources. To meet the system requirement, a frequency-domain analysis² was performed on the spectral polarization and imaging characteristics of the AOTF. Because of the finite geometry of the acousto-optic interaction, the AOTF suffers performance degradations. It is possible to significantly improve the filter performance through the use of apodized transducers. Several different choices of weighting functions and implementation techniques were investigated. Numerical calculations based on the new theoretical work have resulted in optimized AOTF designs with minimized degradations.

© 1990 Optical Society of America