2330nm filters typically use multi-layer interference film technology to achieve high-precision screening of the 2330nm wavelength band by alternately depositing high refractive index (such as TiO ?) and low refractive index (such as SiO ?) materials on the substrate surface. In addition, the dielectric layer and metal layer deposited by semiconductor technology can enhance the adhesion of the film layer, which is suitable for micro light detection in complex environments;