Yizhao Optoelectronics Technology Co., Ltd. produces BP800nm narrowband pass filter. The production process adopts high-temperature evaporation and ion source assisted coating technology to coat hard film. Under the condition of ensuring high transmittance, it can retain strong ability to shield interference light at the same time. The transmittance is up to more than 97%, and the shielding ability in the cut-off wave band is up to more than 99.9%