Absorbent long-pass filter

Longpass Filters are optical components. Their main function is to transmit light with wavelengths longer than a specific cutoff wavelength and block light with shorter wavelengths. They are widely used to separate different spectral bands. For instance, they help eliminate unwanted short-wavelength interfering light in applications such as fluorescence microscopy, Raman spectral analysis and infrared imaging, so as to enhance signal clarity and detection accuracy. Key parameters of such filters include cutoff wavelength, cutoff depth (OD value) and edge steepness. Filters with superior performance generally feature steeper cutoff edges and higher optical density, enabling more effective distinction of light at different wavelengths.