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US 3,944,334 AGranted
Acousto-optic filter
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsTsutomu Yano, Akinori Watanabe
Life of this patent
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Abstract
An acousto-optic filter utilizing the far-off-axis anisotropic Bragg diffraction comprising an optically anisotropic acousto-optic medium embodied by paratellurite. The light entrance surface is slanted to the crystalline axis to make a light beam incident perpendicularly to the surface. The light exit surface is slanted to the direction of the entrance surface to minimize the dispersion of diffracted angle due to light wave length.
Claims6
An acousto-optic filter comprising:
- a medium in which light has two different phase velocities in a propagating direction, said medium having entrance and exit surfaces for light rays,
- transducer means for propagating an ultrasonic wave in said medium, and
- means for directing a light beam to the entrance surface of said medium so as to cause far-off-axis anisotropic Bragg diffraction with said ultrasonic wave, said diffraction occurring at a relatively large incident angle with respect to the plane of the wave front of said ultrasonic wave in said medium, the propagation direction of the diffracted light being displaced from the plane of the wave front of said ultrasonic wave in the same direction as that of undiffracted light to produce optical filtering,
- the entrance surface of said medium being slanted by a predetermined angle from the plane normal to the wave front of the ultrasonic wave.
1 more element
Dependencies are inferred from the claim text.