Si (Silicon) window

Si windows are commonly used in various optical systems, including:

1. Near-Infrared and Short-Wave Infrared Spectroscopy: Si windows are used in spectrometers and other optical systems that operate in the NIR and SWIR range due to their high transmission in these regions.

2. Laser Systems: They serve as protective windows for laser cavities and optical paths in laser devices, especially those operating in the NIR and SWIR spectrum.

3. Thermal Imaging: Si windows are used in thermal imaging cameras and other IR detection systems.

4. Optical Communication: In fiber optic communication systems, Si windows can be used for interfaces and other optical components that require NIR and SWIR transmission.

5. Aerospace and Defense: Si windows are used in sensors, telescopes, and other optical instruments on board aircraft and satellites.

He Rui Optics manufactures silicon windows with diameters from 5 mm to 400mm, and can also provide custom optics on request.  These windows are precision made and cause little to no wavelength distortion. They are an economic choice for many applications.