** CVD diamond film for optical grade application Type: CDL1000 Diamond films are provided with the excellent light transmission, high thermal conductivity and chemical stability. Optical windows made by transparent diamond films are used in many important fileds, such as high power laser window,avigation and spaceflight windows. A common problem for the high power laser window is thermal lensing effect (due to the refractive index change caused by the heat from the light absorbability) of window materials. The main advantage of CVD diamond films as High-power CO2 laser window is its excellent thermal conductivity. Compared the property of optical CVD diamond film and ZnSe window material, though at 10.6μm the absorption coefficient of cvd diamond film is 2-3 order of magnitude than ZnSe, the heat diffusivity of diamond films is 100 times of ZnSe. so the temperature rise of the diamond window is much small than ZnSe window(actually,the temperature rise of ZnSe window is mainly caused by the absorption of anti-reflection film), and the thermal lens effect can be almost ignored.the thermal Simulation results of the ZnSe and optical cvd diamond window at 5kw co2 laser output level show that the temperature rise only 2.5 of diamond window, whereas 17.5 of ZnSe window. The dielectric loss (Tanδ) of optical CVD diamond film in the microwave band is very low, only 8 to 15 x 10-6 in the range of 72-145 GHz. It can be used as window material of high-power microwave tubes. For x-ray, Diamond is not fully transparent. But when the cvd diamond film is very thin, it has little absorption and high transmission for the soft x-ray. So it can be considered as X-ray detector (Such as X-ray enery spectrum) windows or X-ray lithography masks. Typical specification of CDL1000 optical diamond films optic Transmittance8-12μm wavelengh70% nature diamond71% FWHM at 1332cm1 of laser Raman spectrum3.2cm-1 Surface roughness (Ra.nm) <100 thinkness (μm) 800-1000