The so-called narrow-band filter is subdivided from the band-pass filter, and its definition is the same as that of the band-pass filter, that is, the filter allows the optical signal to pass through in a specific wavelength band, and deviates from the band-pass filter. The optical signals on both sides are blocked, and the passband of the narrowband filter is relatively narrow, generally less than 5% of the central wavelength value.
The main function of the narrow-band filter is to pass light of a specific wavelength and reflect (or attenuate) optical components of light of other wavelengths. The half-wave width is usually controlled at 20nm or less, and can be used in ultraviolet, visible light, near-infrared wavelengths, and far-infrared bands. Our company’s narrow-band filters are formed by high-vacuum evaporation of multi-layer hard films and ion-assisted deposition of nanomaterials. Good compactness and high imaging definition.