Emission line optical filters for astronomy available
Hydrogen Alpha (H-alpha) emission line filters are narrow optical filters designed for astronomy applications. The 5 Cavity H-alpha filter has 50% BW of 0.35 nm, a 1% BW of <0.6 nm, peak transmission of ~80%, and is fully blocked to OD 6 out of band. The 2 Cavity H-alpha filter has full-width half-maximum (FWHM) of 0.12 nm and peak transmission of >90%.
Alluxa
Santa Rosa, CA