Spectral Bands: Ultraviolet Filters, Visible Filters, Infrared Filters
Spectral Characteristics: Bandpass Filters, Cut-off Filters, Spectral Filters, Neutral Density Filters, Reflective Filters
Coating Materials: Soft Film Filters, Hard Film Filters
Hard-coated diffraction gratings refer not only to their film hardness but more importantly to their laser damage threshold, making them widely used in laser systems. In contrast, surface soft-coated diffraction gratings are primarily used in biochemical analyzers.
Bandpass Type: Allows light within a selected band to pass through, while blocking light outside the passband. Its optical specifications primarily include the center wavelength (CWL) and the full width at half maximum (FWHM). It is categorized into narrowband and wideband. For instance, the narrowband filter NBF-808 at 808 nm.
Shortwave Pass (also known as Lowwave Pass): Allows light shorter than the selected wavelength to pass through, while blocking light longer than that wavelength. For instance, the infrared cutoff filter, IBG-650.
Long Pass Filter (also known as High Pass Filter): Allows light with wavelengths longer than the selected one to pass through, and blocks light with shorter wavelengths. For example, infrared transmitting filter, IPG-800.