Abstract: An acousto-optical classifier for classifying wide bandwidth signals such as high resolution radar returns of ships or very short pulse length signals of radar emitters. This is accomplished by generating the Fourier transform power spectrum with an acousto-optic cell oriented in the Bragg configuration and a low power coherent light source such as a laser. The power spectrum is detected to provide inputs to a digital classifier.

Abstract: A laser cavity dumper capable of building up energy at a given mode or wavelength while emitting light of a different wavelength is created through use of a Fox interferometer with an electro-optic cell. The Fox interferometer can have either of two configurations. Placement of the electro-optic cell in either of two locations for each of these configurations will either cause the oscillating modes for the laser cavity to scan or undergo discreet shifts of preferred modes. The Fox interferometer can be adjusted for zero output of a selected wavelength under normal operating conditions. A voltage change in the electro-optic cell then changes the resonance from the lossless state through the beam-splitter causing the cavity to dump. A new mode will begin to oscillate as the previous modes are depleted.

Abstract: A target designation system is created by use of a dual-beam illumination bsystem of coherent light. One beam is shifted a discrete frequency level from the other beam. The beams diverge from the source until they overlap on the desired target. The difference in frequency when the beams overlap creates an interference pattern composed of moving fringes which scan across the target. Various receiver systems can be used to identify the scanning fringes and mark the target. In addition, without the use of a receiver subsystem, the illuminations subsystem can still be used as a ranging device which can be tuned to identify range to an object by adjustment of the beams until a maximum intensity moving fringe pattern is observed.

Abstract: A multiple pulse laser from a single resonant cavity. An acousto-optic cell s used to modulate coherent light from a lasing element. Either multiple chirp signals or a masked mirror are used to provide distinct pulses of light. Through proper choice of materials for the acousto-optic cell and use of divergent optics, a higher power level is obtained. Use of a multi-tapped delay line permits a shorter period between pulses due to the linear superposition principle. When the mask embodiment is used, the acousto-optic cell focuses light which scans across the mask. Whenever the focused light passes through the mask, lasing occurs which generates an output pulse.

Abstract: A correlation receiver for detecting and measuring the angle-of-arrival of adio frequency signals, including two antennas, a correlation processor, and a CRT display.

Abstract: A laser using electrogenerated chemiluminescence wherein an organic dye lasing solution is made to flow through or over alternately charged electrodes to charge the dye molecules which are then hydrodynamically diffused to maximize the production of excited molecules, for stimulated emission.

Abstract: An improved acousto-optic laser Q-switch utilizing a chirped fm pulse in the acousto-optic cell to diffract and focus the input beam into a resonating high-Q mode. When the rf acoustic pulse is not wholly within the cell the beam is diverted to the output. A reflective surface is placed on the cell to yield only one output beam and to yield a retroreflective beam back into the cavity for a high Q condition whenever a correctly generated chirp acoustic wave is in the proper position within the cell.