Zinc Selenide Substrates for Blue Lasers.

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

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Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1995
Accession Number
ADA300739

Entities

People

  • Brian J. Fitzpatrick

Tags

Communities of Interest

  • Advanced Electronics

DTIC Thesaurus Topics

  • Acquisition
  • Compound Semiconductors
  • Control Systems
  • Crucibles
  • Diameters
  • Grain Size
  • Materials
  • Melting
  • Melting Point
  • Military Research
  • Optical Detection
  • Phase
  • Phase Transformations
  • Single Crystals
  • Technical Information Centers
  • Transitions
  • Zone Melting

Fields of Study

  • Physics

Readers

  • Materials Science and Engineering.
  • Mathematics or Statistics
  • Software Engineering

Technology Areas

  • Directed Energy