Optical grade silicon (Si) is used in infrared optics for systems operating in the mid-infrared range MWIR 3-5 um, however, special grades of silicon (High Resistivity Float Zone Silicon (HRFZ-Si)) are also used for operation in the terahertz (THz) wavelength range and are an important material for terahertz applications.

Hengrun optics produces the three types of optical silicon: 

- Optical Czochralski Silicon (OCz-Si) 

- Float Zone Silicon (FZ-Si) 

- High Resistivity Float Zone Silicon (HRFZ-Si)

The transmission of a material in different wavelength ranges depends not only on the type, but also on the thickness of the material, however, at the mid-infrared range MWIR 3-5 um, there is practically no difference in the transmission of various types of optical grade silicon. In addition, at the range of 3-5 microns, the dependence of transmission on the thickness of the material is insignificant, but this dependence strongly increases and becomes significant in the range of long waves LWIR and THz region.

Hengrun optics has the capacity to perform diamond turning, polishing, and  custom manufacturing for all size orders from prototype to production quantity.