Accession Number : ADD017879

Title :   Laser Hardened Backside Illuminated Optical Detector.

Descriptive Note : Patent, Filed 26 Dec 90, patented 17 Oct 95,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Bartoli, Filbert J ; Hoffman, Craig A ; Meyer, Jerry R ; Lindle, James R

Report Date : 17 Oct 1995

Pagination or Media Count : 5

Abstract : A protective layer laser hardens an optical detector. The material for the protective layer is Hg1-yCdyTe, where y is selected so that the band gap of the protective layer is higher than the expected energy level for photons impinging on the protective layer. Photons with energy levels lower than the band gap are transmitted by the protective layer while photons exceeding the band gap energy level are absorbed or reflected by the protective layer. A semiconductor junction can be formed on the opposite side of the substrate from a HgxCdxTe layer with a band gap lower than the expected energy level, so that photons transmitted through the substrate are absorbed in the HgxCdxTe layer and, therefore, detected at the junction. At sufficiently high intensities where detector damage could result, the protective layer switches so that the incident photons are either absorbed or reflected, thus protecting the detector from damage.

Descriptors :   *PROTECTIVE COATINGS, *RADIATION HARDENING, *PATENTS, HIGH RATE, INTENSITY, SUBSTRATES, ILLUMINATION, SEMICONDUCTOR JUNCTIONS, OPTICAL DETECTORS, ENERGY LEVELS, MERCURY CADMIUM TELLURIDES, LASER DAMAGE

Subject Categories : Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE