Angular-Spectral Characteristics of Acousto-Optic Tunable Filters Based on Mercurous Halide Crystals

Area of Science:

• Optics and Photonics
• Materials Science

Background:

• Acousto-optic (AO) devices rely on phase-matching geometries for functionality.
• Spectral imagers using acousto-optic tunable filters (AOTFs) face throughput limitations due to light separation angles.

Purpose of the Study:

• To develop an analytical model for predicting angular-spectral properties of diffracted beams in mercurous halide crystals.
• To investigate the relationship between separation angle and various optical and acoustic parameters.

Main Methods:

• Development of an analytical model to elucidate angular-spectral properties.
• Computation of correlations between separation angle and parameters like incident angle, polarization, acoustic angle, and crystal birefringence.
• Experimental validation using mercurous halide and tellurium dioxide crystals.

Main Results:

• The model successfully elucidates the angular-spectral properties of diffracted beams.
• Confirmed correlations between separation angle and key parameters.
• Higher crystal birefringence was shown to significantly amplify the separation angle.

Conclusions:

• The developed analytical model aids in designing acousto-optic devices with large separation angles.
• Enhanced separation angles improve systematic throughput in spectral imaging applications.
• Mercurous halide crystals are promising for AO devices due to their wide spectral range and birefringence properties.