Abstract: An acousto-optic modulator utilizing light diffraction by phased acoustic waves in a birefringent crystal. The wavevector of the resultant acoustic wave is selected so that the tangents to the loci of the wavevectors of the incident and diffracted light are parallel. This provides a large acceptance angle for the acousto-optic modulator. By simultaneously choosing the acoustic wavevector to be tangential to the locus of the diffracted light wavevector, the acousto-optic modulator also achieves increased modulation bandwidth.

Abstract: The invention is a method that considerably improves the rapidity of collection and recognition of electrical signals that are mixed with other signals that impede direct access. The subject of the invention is a method for detection, recognition and use of significant trains of modulated signals on a carrier frequency. The apparatus which provides for the method utilizes a sole crystalline Bragg cell wherein two signal trains travel colinearly through the cell.

Abstract: An electronically tunable optical filter utilizing noncollinear acousto-optic interaction in an acoustically anisotropic, optically birefringent crystal. The directions of optical and acoustic waves are chosen so that the optical ray is collinear with the group velocity of the acoustic wave. The collinear beam configuration provides increased spectral resolution and reduced drive power.

Abstract: A light modulator includes an interdigital transducer having a plurality of interdigital electrode fingers for generating surface elastic waves having respective different frequencies in an optical waveguide. The electrode fingers are oriented in different directions to enable the generated surface elastic waves to diffract a light beam guided through the optical waveguide, while satisfying the Bragg condition for diffraction. A driver applies high-frequency voltages having respective frequencies to the electrode fingers to generate the surface elastic waves, respectively. The application of the high-frequency voltages to the electrode fingers is turned on and off by switching circuits. The light modulator is incorporated in a recording device.

Abstract: A multi-channel/multi-layer optical gate contained within a fiber-optic housing having any number of optical cells disposed within the housing. The optical cells are made up of non-linear organic polymers surrounded by a piezoelectric crystal, which is in turn connected to a photovoltaic device. When the photovoltaic device is activated, the piezoelectric crystals cause the non-linear organic polymers to change their refractive index, causing an interruption of a reference laser beam. An output detector is disposed within the fiber-optic housing for detecting the reference laser beam.