It is the main optical element for distinguishing a given wavelength in various spectral optical devices, such as monochromators and spectrographs, which are intended for scientific research and production needs.

Technologies used:
- Technology of manufacturing by a method of cutting by a diamond cutter on a high-precision dividing machine with interference control.
- Technology of vacuum deposition of reflective metal coatings.

Benefits:
- High diffraction efficiency.
- Work in high orders of the spectrum