Infrared Optical Properties of Thin CO, NO, CH4, HC1, N2O, O2, N2, Ar, and Air Cryofilms
Abstract
The infrared spectral transmittance of cryofilms formed by CO, NO, CH4, HC1, N2O, O2, N2, Ar, and air were measured. These films were condensed on a 20 K germanium substrate and ranged in thickness from 0.25 to 15 micrometer; the deposition pressure for the films was 2 x 10 to the -7th power torr. Transmission spectra were obtained for the 500- to 3700/cm wavenumber range using a Fourier transform spectrometer. Values of complex index of refraction (n = n - ik) for the cryodeposits were derived from the experimental data using an analytical model and the nonlinear least-squares method. The analytical model treats the germanium as a thick noninterfering film and the deposit as a thin film. Results from the least-squares method are also compared with a Kramers-Kronig determination of the real part of the index of refraction. The optical properties (n,k) of such cryofilms are reqiured for predicting the degradation of contaminated, cryogenically cooled optical surfaces.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1980
- Accession Number
- ADA088269
Entities
People
- A. Matthew Smith
- Bobby E. Wood
- J. A. Roux
- R. R. Plyler
Organizations
- Arnold Engineering Development Complex