The selection of materials and technologies used in optical systems depends on the wavelength of the light used in the system.
Fused silica can be particularly advantageous in the ultraviolet (<300 nm) and in the far infrared (800-3500 nm) or where very high optical homogeneity is required. In each case, the optimum fused silica material grade must be selected. For instance, depending on the raw material source (quartz containing mineral or synthetic chemicals) and the manufacturing method which leads to different levels of OH, each grade of silica glass can be optimized for UV transmission, IR transmission, broadband transmission, and different levels of homogeneity in one dimension, two dimensions or three dimensions. For even shorter wavelengths of light (EUV), it may be impossible to use transmissive optics, then reflective systems (plano or curved mirrors) may be used.
The number of optical concepts, processing and machining is practically endless. In the following, we will cover a few applications where fused silica is the material of choice.