Optical Filter products are mainly classified according to spectral band, spectral characteristics, film materials, application characteristics, etc.
Spectral band: ultraviolet filter, visible filter, infrared filter
Spectral characteristics: band-pass filter, cut-off filter, spectroscopic filter, neutral density filter, reflective filter
Film material: soft film filter, hard film filter
Hard film filter: not only refers to film hardness, but also its laser damage threshold, so it is widely used in laser systems; Soft film filter is mainly used in biochemical analyzer.
Bandpass type: the light of the selected wave band passes through, and the light outside the passband is cut off. Its optical indicators are mainly the central wavelength (CWL) and half bandwidth (FWHM), which are divided into narrowband and broadband. For example, narrowband filter short wave pass type (also called low wave pass): the light shorter than the selected wavelength passes through, and the light longer than the wavelength is cut off, such as infrared cut-off filter long wave pass type (also called high wave pass): the light longer than the selected wavelength passes through, and the light shorter than the wavelength is cut off, such as infrared transmission filter.
