Infrared transmission in GE-SB-SE glasses
- Cite this article as:
- Rechtin, M.D., Hilton, A.R. & Hayes, D.J. JEM (1975) 4: 347. doi:10.1007/BF02655410
- 135 Downloads
The infrared transmission properties of GeSbSe glasses have been investigated in order to determine the extrinsic and intrinsic absorption effects which limit their performance in avionic infrared systems and as CO2 laser windows. Extrinsic effects were found to include oxide and carbonaceous contamination. These detrimental contaminants were negated by preparation techniques such as distillation through quartz frits and addition of a gettering agent such as Al. Removal of the large extrinsic absorptions revealed the lower level intrinsic absorptions. The long wavelength infrared cutoff appears to be determined by higher order excitations of several fundamental vibrational modes, near 245 cm−1 for Ge-Se and 180 cm−1 for Sb-Se. Variation of the composition resulted in changes in the absorption coefficient in the 8–12 micron atmospheric window. These changes are due to the formation of distorted molecular units and to mixtures in the types of bonds formed among Ge, Sb, and Se. At 10.6 microns the absorption coefficients were found to very from a high of 0.024 cm−1 to a low of 0.008 cm−1.