Development and characterization of two-transducer imaging acousto-optic tunable filters with extended tuning range

We developed two high-quality large-aperture acousto-optic tunable filter cells in TeO2 with more than two octaves spectral coverage for hyperspectral imaging applications from the visible to the midwave infrared: the first cell covers from 0.43 to 2.1 microm and the second from 0.69 to 4.0 microm. The key feature of these cells is a special design of two transducers in tandem with a special bonding technique that results in such a wide spectral coverage with virtually no acoustic and electrical loss due to careful matching of both acoustic and electrical impedances. Each of these cells has high spectral transmission, as well as low power requirement. We discuss the design, characterization, and performance results for these cells.