Accession Number : AD0484009

Title :   COHERENT OPTICAL ARRAY TECHNIQUES.

Descriptive Note : Interim quarterly rept. no. 3, 3 Nov 65-2 Feb 66.

Corporate Author : SPERRY GYROSCOPE CO GREAT NECK NY ELECTRO-OPTICS GROUP

Report Date : MAY 1966

Pagination or Media Count : 48

Abstract : A path-length-stabilized Mach-Zehnder interferometer configuration for coherent paralleled operation of two neodymium-glass amplifiers has been constructed and is now operational at 1.06 microns. Interferometer alignment during the interpulse period is maintained through use of a 1.0621 microns cw helium-neon gas laser as the phase reference source. A pulsed neodymium-doped calcium tungstate oscillator operating at 1.0582 microns furnishes the input signal to be amplified by the paralleled amplifiers. The glass amplifiers yield 10 db gain when pumped by an FX-65B flashlamp at 2000 joules input. Optical distortions arising from thermal gradients in the laser rod are significant, and means for compensation and reduction are discussed. The output spectra of 1.065 microns cw Nd:YAG oscillators were measured. The output is multifrequency with random fluctuation of mode amplitudes, but quite narrow in total spectrum width (about 6 Gc) compared to fluorescent width (about 90 Gc). Intracavity mode-selection techniques will be required for obtaining single-frequency oscillation. (Author)

Descriptors :   *OPTICAL RADAR), (*LASERS, INTERFEROMETERS, NEODYMIUM, ALIGNMENT, HELIUM, NEON, DOPING, CALCIUM COMPOUNDS, TUNGSTATES, FLASH LAMPS, OPTICAL PUMPING, GAIN, PULSE AMPLIFIERS, OSCILLATORS, GARNET, YTTRIUM COMPOUNDS, ALUMINUM COMPOUNDS, ABSORPTION SPECTRA, XENON LAMPS.

Subject Categories : Lasers and Masers

Distribution Statement : APPROVED FOR PUBLIC RELEASE