Accession Number : AD0906204

Title :   High Average Power Injection Laser Illuminator.

Descriptive Note : Final rept.,

Corporate Author : IBM FEDERAL SYSTEMS DIV GAITHERSBURG MD

Personal Author(s) : Eros, Stephen

Report Date : DEC 1972

Pagination or Media Count : 85

Abstract : This final report describes the work done in developing the technology which would result in the design, fabrication, and delivery of a High Brightness Gated Injection Laser Illuminator. The stated goals were 30 W of average power in a beam of 8 by 8 mrad divergence, using a lens of larger than 5 inches in diameter. The approach selected at the start of the program was to use 28 glass fibers, in the form of ribbons, to transmit optical flux from the emitting junctions of 28 diodes into an integrator having an emitting surface of 0.056 by 0.056 inch (the requirement for plating the fibers later in the program increased the aperture size to 0.060 inch by 0.075 inch.) A lens of 7.1 inches focal length then projects the required narrow beam. Each individual diode was required to emit 2.0 W of average power in order to obtain 30 W of beam power. Technology for diode mounting and heat sinking, diode-fiber interfacing, arraying, and electronically driving, and for achieving individual fiber throughput was successfully developed. Average powers as high as 4.5 W (diode output) per diode/fiber combination were domonstrated for one such combination. The major problem encountered was melting of the ribbons at the point where ribbons converge together at the integrator holder. A solution to the problem was found by plating a thin layer of copper on the surface of the ribbons to conduct heat from the confined region. These plated ribbons have been demonstrated to carry away at least twice the required optical flux.

Descriptors :   *LASERS), (*OPTICAL TARGET DESIGNATORS, INTEGRATORS, SEMICONDUCTOR DIODES, GALLIUM ARSENIDES, FIBER OPTICS, INFRARED LASERS, INFRARED RADIATION, ILLUMINATION, BRIGHTNESS.

Subject Categories : Lasers and Masers
      Optical Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE