Notch filters

The negative filter, also known as the "notch filter", is mainly used to cut off the spectrum of a specific band within a certain spectral range, and at the same time transmit most of the spectrum except for the cut-off band. It has the advantages of high throughput on both sides, OD3-OD6 background of cut-off band, and steep transition zone. Applications: Raman spectroscopy, laser protection systems, medical endoscopes, etc.