Comparison of 1 micron transmissive optical materials for high power lasers

With the advent of very high-power direct-diode, fiber and disk lasers, choosing the right optical material for a given application is vitally important. What will determine the best optic for the application are a combination of factors about the application itself and the material properties of the optics. Application factors of importance include the laser power, laser type, and the users’ application. Important material properties that the designer must consider in the selection of optical materials are the fundamental optical, thermal, and mechanical properties as well as the cost of purchasing the optics. This paper will discuss in general the laser and application factors, however, the main focus will be on various properties of the available optical materials and the relative cost of finished optics. During the discussion of the material properties we will present a figure of merit calculation for optical materials that can be used to determine the suitability of an optic to an application. We will discuss the use of Fused Silica, Zinc Sulfide MultiSpectral (ZnS MS), and Zinc Selenide (ZnSe) for lenses and windows. Finally we will present some novel optic configurations that can be diamond turned for special beam shaping applications such as heat treating, cladding, and welding.