With our partner EKSMA Optics we produces Notch filters that ensure effective blocking of the designated laser wavelength and feature OD >6.0. While the Notch filter rejects a very narrow wavelength range which is typically 15-20 nm at FWHM, it has high transmission in broad bandpass ranges. The backside of the filter is broadband anti-reflection coated to minimize the reflection at passband regions. EKSMA Optics offers standard Notch filters for 488, 514, 532, 561 nm emitting lasers. Custom Notch filters for other wavelengths and different OD levels available on request.
Thin-film Notch filters, or rejection filters, can be used for numerous applications, where some specific laser wavelengths have to be blocked, while others have to be transmitted. They are commonly used in Raman spectroscopy, medical laser systems, laser safety applications, and laser-based fluorescence instruments.