The understanding and characterization of low level absorption in window materials is important for applications involving high energy lasers and hot windows in front of detectors. Low concentration impurities are important as well as disorders and defects. Such mechanisms can produce weak absorption that can manifest itself as background continuum absorption between the band gap and the multiphonon absorption edges. This so called weak absorption tail has been characterized in amorphous semiconductors and glasses, but not as completely in crystalline or polycrystalline materials that are typical durable window materials.

Low-level absorption in the visible and near infrared has been reported for single crystal o-ray sapphire and a limited set on other crystalline based material. A survey of reported measurements in regions of high transparency for such materials is presented.

Date Published: 3 May 2017
PDF: 7 pages
Proc. SPIE 10179, Window and Dome Technologies and Materials XV, 101790B (3 May 2017); doi: 10.1117/12.2263570

Published in SPIE Proceedings Vol. 10179:
Window and Dome Technologies and Materials XV
Brian J. Zelinski, Editor(s)