27 Sep 2021
Notch filters are commonly called suppression filters, band-stop filters, etc. The characteristic of this filter is that it can pass most wavelengths with almost no loss, and the specified band (stop band). The light decayed to a fairly low level. They are just the opposite of the bandpass filter.
Relative to the application of laser emission, the notch filter is very important. In the spectrum experiment, in order to obtain a good signal-to-noise ratio, it is very critical to suppress the pump laser. This can be achieved by placing a notch filter on the detection channel. Notch filters are often used in spectrometers, laser-based fluorescence instruments and biomedical laser systems.