A line of deep optical thin-film notch filters for use with standard laser lines has been unveiled by Semrock Inc. for Raman spectroscopy, fluorescence and analytical instrumentation applications. Optical density is >6 attenuation of the laser line, and the filters maintain >90% transmission outside the notch. Typical notch width is 17 nm at 532 nm. The filters are made with hard-coating technology, without any adhesives in the optical path. The company says that the combination of stable ion-beam sputtering and proprietary deposition control technology and software results in filters that deliver high optical performance.