High-Performance Narrowband Optical Filters: Precision Thin-Film Coatings for Demanding Applications
Narrowband optical filters isolate a precisely defined wavelength band from a much broader optical background, delivering higher signal-to-noise ratios and selective detection of weak optical signals. In this edition we show how I-Photonics engineers complex PARMS interference coatings — over one hundred dielectric layers — and demonstrate an astronomy-grade [S II] narrowband filter near 673.1 nm with 93.89% peak transmission and a ~3.1 nm FWHM.
