In optics, a window is a substrate material that is flat, parallel and good surface finish. The degree of flatness, parallelism and surface finish can range from commercial quality to laser quality and the price goes up exponentially with these parameters. The type of materials that are used will determine the wavelength of light that will pass through the window. Substrate materials are available to transmit from the UV to Far Infrared. Anti-Reflection Coating are typically applied to both surfaces to increase transmission in the desired wavelength bands.
Custom optical components, thin film coatings, photolithography and optical and mechanical fabrication.