Hyperspectral imaging performance of a TeO2 acousto-optic tunable filter in the ultraviolet region.

A compact UV hyperspectral imager can be designed with an acousto-optic tunable filter (AOTF) installed in front of an enhanced CCD camera. Tellurium dioxide (TeO2) is the most commonly used crystal for AOTFs from 0.4 to 4 microm. We conducted an experiment to determine the UV spectral response of an imaging TeO2 AOTF in tandem with a known KDP AOTF and obtained good-quality hyperspectral images by using the TeO2 filter down to 365 nm. We compared the performance of the TeO2 filter-based hyperspectral imager with an imager based on a KDP filter because currently the latter is the best available material for the UV, and we found the performance of the TeO2 imager in the range 355-480 nm to be superior to that of a KDP imager. We present our experiments and the results obtained.