Absorption of thin film materials at 10.6 microm

Absorption indices at a wavelength of 10.6 mum for thin films of As(2)S(3), GeSe, BaF(2), ZnSe, and CdTe were measured by calorimetric techniques with a CO(2) laser. The values obtained, 4.6 x 10(-4), 1.4 x 10(-3), 2.8 x 10(-3), 2.8 x 10(-3), and 5.0 x 10(-3), respectively, were significantly greater than the corresponding values for the bulk materials. This difference was least for the vitreous films, As(2)S(3) and GeSe, which also had a lower absorption than the remaining polycrystalline films. Details are presented of the microstructure of the films as determined by scanning electron microscopy and k-ray diffraction.