Trw Limited

David B Hall

Paul L Greene

Reynold S Kagiwada

Donald C Winter

William L Shackleford

A modulator for a laser such as a chemical or electrically excited laser radiating in the region between approximately 2 and approximately 5 microns. The modulator consists of a transparent ferroelectric ceramic of the type known as PLZT. Such a polycrystal is disposed in the laser cavity. An electric voltage is applied to the crystal for causing it to exhibit optical birefringence, thus spoiling the Q of the laser cavity. Further, means is disposed in the laser cavity for linearly polarizing the radiation such as one or more Brewster windows transparent to the radiation. The crystal is cooled by fluid means such as a gas transparent to the radiation. Further, the crystal is mounted by means having an acoustic impedance substantially matching that of the crystal so that mechanical stress waves set up in the crystal are not reflected back into the crystal.

Near infrared laser modulator

An acousto-optic device suitable as a correlator, convolution integrator or Fourier transform device. The device comprises a piezoelectric substrate or crystal such as lithium niobate. The substrate is covered by a thin, outer layer having higher index of refraction than the substrate and a thickness on the order of 50 micrometers. Two acoustic transducers such as interdigital transducers are disposed on opposite ends of the crystal to launch two acoustic surface waves in opposite directions. A laser beam is guided through the outer layer and is coupled with the two acoustic waves to generate either a correlation function, a Fourier transform or a convolution integral depending on the signals impressed thereon.

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Manhattan Beach, CA, United States of America

David B Hall