Accession Number : AD0918880

Title :   High Average Power Diode Laser Illuminator. Phase 1/Phase 2.

Descriptive Note : Final rept. 2 Apr-16 Nov 73,

Corporate Author : IBM FEDERAL SYSTEMS DIV GAITHERSBURG MD

Personal Author(s) : Ludwig, Edmund D. ; Eros, Steven

Report Date : MAR 1974

Pagination or Media Count : 70

Abstract : The Phase I effort was directed toward verification of cryogenic laser diode optic technology for optical throughputs of more than one watt average power per fiber. In the test model, 17 diode module/fiber units out of a complement of 28 were operated simultaneously; the bundled fibers formed a 60 by 80 mil source which emitted 21 watts at 9 per cent duty factor through an f 1.6 optical system. The test model circular array configuration imposes disadvantages during fabrication which prevents successful operation of the full complement of module/fiber units. The Phase II task consisted of design studies and experiments to evolve a linear laser diode fiber optic array. An electrical analog model of the array thermal resistance path was constructed to experimentally solve the three-dimensional heat flow problem. A Gallium-Indium eutectic solder which is a liquid at room temperature was developed to provide a high conductivity interface material. Conceptual array designs were examined for modularity, ease of fabrication, and repairability. Sub-array tests using extruded optical quality fibers indicated potential fiber melting due to the insulating vacuum surrounding the array. A theoretical analysis of fiber cooling using a nitrogen gas filled array chamber showed a marked advantage for gas-cooled fibers. The proposed final design is a linear, modular array using equal length metallized fibers in a gas-filled chamber. The source size is 66 x 66 mils using 30 diode/fiber units on 15 modules. (Author)

Descriptors :   *SEMICONDUCTOR DIODES), *GALLIUM ARSENIDE LASERS), (*SEMICONDUCTOR LASERS, (*LASER TARGET DESIGNATORS, SEMICONDUCTOR LASERS), (*FIBER OPTICS, IMAGE INTENSIFIERS(ELECTRONICS), LASER BEAMS, LIGHT TRANSMISSION, ILLUMINATION, HIGH POWER, CRYOGENICS, COOLING, GALLIUM, INDIUM, EUTECTICS, SOLDERING, NITROGEN, HEAT TRANSFER, ALIGNMENT, THERMAL PROPERTIES, SAPPHIRE, FABRICATION, CLADDING.

Subject Categories : Lasers and Masers
      Fire Control and Bombing Systems
      Fiber Optics and Integrated Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE