Windows for High-power Infrared Lasers

Considerable progress has been achieved in recent years on improving the optical properties of CVD diamond and in making this material available in large sizes and with reproducible and consistent properties [4,5,35] so that its use in actual laser systems has become a practical reality [48]. This section reviews the technical issues relevant to the performance of windows for high power lasers comparing the specific case of CVD diamond and ZnSe for the transmission of CO2 laser beams. 

A major requirement for windows used in the transmission of high power beams is the reduction of wave-front distortion which may result in defocusing of the beam and loss of power density. There are two major sources of wave-front distortion thermal effects and geometrical or form-shape aberrations [49]. 

A window can absorb heat from the laser beam by intrinsic bulk absorption or at the surfaces (through intrinsic surface absorption mechanisms or at the anti-reflection (AR) coatings). The absorbed heat induces radial and axial temperature gradients which in turn result in two distinct forms of optical distortion  

2 Applications of Diamond Synthesized by Chemical Vapor Deposition 

Property at 300 K Diamond (optical-grade DIAFILM) ZnSe 

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