Long Pass Filter

A long pass filter is an optical component. Its core function is to allow light with wavelengths longer than a specific cut-off wavelength to pass through while blocking light with shorter wavelengths. It achieves spectral selection based on the principle of thin-film interference or material absorption properties. Widely applied in fields such as fluorescence analysis, Raman spectroscopy, astronomical observation and machine vision, it helps separate light signals of specific wavelengths, reduce interference and improve detection accuracy or imaging quality.