ADAPTIVE MULTISPECTRAL FILTER

Tunable, acousto-optic filters (AOTF) for operation in the UV-VIS-IR spectral ranges are important elements in the design of advanced sensors for target acquisition, and discrimination. Their small size, random-access wavelength selection, rapid scan rates, and all solid-state construction with no moving parts, provide an attractive alternative to monochromators and filter wheels, for many applications such as spectroscopy, analytical chemistry, clinical diagnostics, and on-line sensors for process control. Drawbacks of current AOTFs are (a) made from a single large birefringent crystal which may be difficult to obtain and expensive to manufacture, and (b) for a given design the angular aperture and spectral resolution characteristics are fixed. This work explores the use of non-crystalline polymer materials of variable birefringence for the design and fabrication of novel AOTFs of increased versatility and ruggedness, as well as significantly lower manufacturing costs.