Optical windows are usually in the form of flat plates of a transparent medium and are use or isolating optical systems or components against detrimental influences from the environment.These windows have polished faces that are relatively parallel. They are used for safeguarding laser output. Their high transmission makes them ideal for most industrial and laser protecting applications. These windows AR coated so as to provide improved transmission when used in industrial displays or computer monitors. Some of the commonly used optical windows are glasses like fused silica, sapphire window and BK7 and so on.
Silicon Window
Silicon Window has good transmission in the range from 1.2 to 7.0 µm, with minimum or no distortion of the transmitted signal. As it has low density in comparison to other materials, it is ideal for optical system where weight is the crucial factor. They also have high thermal conductivity and are less brittle than Germanium windows making it suitable for laser windows. However, as Silicon has strong absorption band at t 9 µm, it is not suitable for use with CO2 laser transmission applications. Most manufacturers provide custom made optical window by combining silicon and other materials for varied applications such as discs and rods, laser fusion optics, reference surfaces, debris shells and so on.
Sapphire Window
Sapphire windows a sturdy material having high mechanical strength, thermal and chemical resistance and is scratch resistant. Sapphire optical windows are ideal for applications where high pressure, vacuum and corrosive atmosphere are important considerations. These sapphire windows have high-precision polished surfaces, surface accuracy and parallelism. These windows are ideal for high temperature, high pressure or strong vacuum environments such as pressure optical windows, furnace view ports, submersible ROVs, gas and oil analysis, barcode readers and IR analytical devices.
There are many reputed manufacturers engaged in making precision optical window fabricated from several different substrates for use in a large variety of laser and industrial applications. They provide expert advice for the right precision window selection for varied industry applications.
