Development of Multispectral Sandwich-Type IR Windows.
Abstract
Composite or sandwich-type multispectral windows up to 4 x 6 inch in size have been fabricated by a Westinghouse-developed technique called optical brazing. Of the numerous cladding, substrate and adhesives tested, the ZnS/ZnSe composite window is now the most promising for airborne common aperture systems. Optical path differences in the assembled windows stem mainly from material property variations in the component parts, not from the binding agent. These path differences can for the most part be corrected during final polishing of the composite window. The ZnS/ZnSe window transmittance with AR coating exceeds the 60% visible wavelength and 1.06 and 95% 8-12 micrometer transmittance requirements. Composite window specimens are as rain erosion resistant as monolithic ZnS. Optical brazing is a versatile technique for composite window fabrication and has been used to join other cladding and substrate combinations such as MgF2/ZnSe. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1977
- Accession Number
- ADA045655
Entities
People
- G. B. Brandt
- J. Schruben
- R. A. Hoffman
- R. H. Hopkins
- W. E. Kramer