<title>High-temperature optical scatter characteristics of CVD diamond and natural type IIa diamond</title>

In support of Strategic Defense Initiative Organization objectives to develop optical quality chemical vapor deposition (CVD) diamond windows, the infrared optical scatter characteristics of thin, polished, free-standing CVD and natural type IIa diamond films were measured at room temperature and 500 degree(s)C. The CVD diamond scatter characteristics are compared with those of the natural type IIa diamond of similar thickness at identical temperature. The diamond samples were about 10 to 30 mm in size and 250 to 500 micrometers in thickness. The diamond samples were provided by various manufacturers and laboratories both in the United States and abroad.