Patent ID: 7944607

Claim:
A device for spectral high-resolution acousto-optic programmable filtering in the infrared region of an incident optical wave comprising: a birefringent acousto-optic crystal, from the tetragonal crystal class, having a slow acoustic wave propagation velocity along the [ 110 ] axis, a piezoelectric transducer disposed on a surface of the birefringent acousto-optic crystal, means for inputting an incident ordinary optical wave into said birefringent acousto-optic crystal, in a plan of said crystal containing the axis [ 001 ] and [ 110 ], means for generating in the birefringent acousto-optic crystal a transverse acoustic wave with wave vector, in said plan of said crystal containing the axis [ 001 ] and [ 110 ], through said piezoelectric transducer, disposed so that: the energy of the transverse acoustic wave propagates along a same axis but in an opposite direction to the energy of said incident optical wave, and an extraordinary optical wave, resulting from the acousto-optic interaction between said incident optical wave and said transverse acoustic wave, which is diffracted with wave vector, substantially perpendicularly to the direction of said incident optical wave.