Acoustically tuned optical filter system

Claim 1

An acoustically tuned optical filter system for use with electromagnetic radiation in the visible/infrared light wavelength region, said optical filter system comprising: a. a polarizer in optical alignment with said radiation, whereby said radiation impinges upon and is transmitted by said polarizer as polarized light; b. an acoustically tuned optical filter assembly disposed in optical alignment with said polarizer, wherein this assembly includes: (1) a plurality of rotatable crystals made of acousto-optical material, with each crystal of said plurality being in parallel spaced relationship with its adjacent crystal, and with each crystal having its front surface and its extraordinary axis in perpendicular relationship to said transmitted radiation, whereby said crystals can be rotated such that said extraordinary axes of said crystals can be selectively rotated angularly, and thereby variably, with respect to each other, and wherein each crystal of said plurality of crystals has two mutually opposed side edges; and (2) means, operably associated with said plurality of crystals, for acoustically exciting each of said plurality of crystals, said means for acoustically exciting each crystal includes a different pair of acoustic generators operably associated with each crystal, with one generator of said pair of generators operably associated with one of said two edges of its crystal, and with the other generator of said pair of generators operably associated with the other edge of said two edges of its crystal; and c. an analyzer in optical alignment with said acoustically tuned optical filter assembly.