Colored glass filters are optical components that are made by adding metal oxides or rare earth elements (such as cobalt, nickel, copper, etc.) to the glass substrate, so that they can present specific colors and selectively absorb light spectra. Their essence is to utilize the absorption differences of materials to different wavelengths of light to achieve the function of "passing through the target wavelength band and blocking other wavelength bands", which belongs to absorption-type filters. Their characteristics include wider spectral bands and good temperature stability.