Interference filters transmit light with very narrow or sharply defined
transmission bands or reflect desired wavelength regions. The lights
outside this region will be blocked. Filters are applied to many optical
instruments such as spectrometers, monochromators. Long wavepass filters are
designed to pass the higher wavelengths in a band and reflect the
shorter wavelengths while short wavepass filters are designed to pass
the shorter wavelengths and reflect the higher wavelengths. F-B filter
is a kind of all-dielectric filters that has a narrow half-width and
high maximum transmittance.
Hard coating filter provides a high
level of damage threshold, and so widely used in laser system. While
soft coating filter is applied to biochemical analyzer.