Accession Number : ADA300739

Title :   Zinc Selenide Substrates for Blue Lasers.

Descriptive Note : Progress rept.,

Corporate Author : OPTICAL SEMICONDUCTORS INC PEEKSKILL NY

Personal Author(s) : Fitzpatrick, Brian J.

PDF Url : ADA300739

Report Date : APR 1995

Pagination or Media Count : 3

Abstract : A new crucible was designed for the zone melting growth of zinc selenide (ZnSe). This is partially compatible with the old crucible, in that most of the parts are interchangeable. The seeding area has been reduced to 6 mm diameter at the bottom, but the full 25 mm boule diameter has been reached by 30 mm above the bottom. This allows a seeding neck of considerably smaller diameter than the single crystal grain size in the case of a round bottom crucible. The transition to the full diameter is gradual, with the radii of curvature exceeding 50 mm. Design of a new control system has begun. This will be based on optical sensing in a closed-loop configuration. Previously, open-loop power control had been used, with circuitry modified to reduce fluctuations; these modifications will be utilized to damp out the oscillations around the set point that are common in tight control systems. jg p.1

Descriptors :   *SUBSTRATES, *LASERS, *BLUE(COLOR), *ZINC SELENIDES, OPTICAL PROPERTIES, OPTICS, CONTROL SYSTEMS, DETECTION, GROWTH(GENERAL), PHOTOLUMINESCENCE, SINGLE CRYSTALS, GRAIN SIZE, X RAYS, NITROGEN, CURVATURE, FLUORINE, CONFIGURATIONS, ELECTRON DONORS, POWER, CIRCUITS, WAFERS, ELECTRON ACCEPTORS, OSCILLATION, OPEN LOOP SYSTEMS, RADIUS(MEASURE), CLOSED LOOP SYSTEMS, TIGHTNESS, EXCITONS, TWINNING(CRYSTALLOGRAPHY), SEEDING, CRUCIBLES, ZONE MELTING.

Subject Categories : Inorganic Chemistry
      Lasers and Masers
      Crystallography
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE