Scattering and absorption of CVD diamond windows

摘要

Diamond grown with chemical vapor deposition (CVD) processes is currently being considered for use as a long wave infrared (LWIR) dome material for advanced missiles. In order to assess diamond's suitability for this application, a complete understanding of the optical properties of CVD diamond is needed. This includes a determination of the relative amount of bulk and surface scattering, and a measurement of the absorption in thick CVD diamond films. In this paper, we present scattering data for visible (0.633 $mu@m) and infrared (10.6 $mu@m) wavelengths from optically smooth thick diamond films. Scattering data from the aluminized front and back surfaces of the films is also reported. These measurements, together with first order scattering theory, provide a means for determining the component of scattered radiation which is due to bulk scattering. The bulk absorption is also estimated from a detailed energy balance using reflectance, transmittance and scattering measurements.