Opto Mechanical Design Aspects of High Power Laser Mirrors

Abstract

Abstract Reflecting Optics is a critical component of any High Power Laser (HPL) based System. With the advancements in Laser Sources, power is continuously increasing with decrease in operating wavelength. This has lead toeven more sophisticated upto mechanical design of HPL optics. A large portion of the incident power is reflected and the rest is absorbed and transmitted in various stages. This absorbed power is very detrimental which affects the system performance and may even lead to catastrophic system failure. The mechanism of laser reflection, absorption and transmission is explained in a simple way. General requirements and desired properties of substrate materials are listed. Various metallic and non metallic substrate materials are tabulated along with their physical and mechanical properties. The materials are compared on the basis of their Figure of Merit (ratio of thermal conductivity to coefficient of thermal expansion) andstrength to weight ratio (E/ρ). Finally thermo structural analysis is carried out fora specific design input and results are formulated.