656.8-1 OD4

Ultra-narrowband optical interference filter with a 656.8 nm center wavelength (CWL), a 1 nm full-width at half-maximum (FWHM), and wide-range OD4 out-of-band blocking from 200 nm to 1200 nm. This is a multi-cavity filter with moderately steep edges, a flat top, and transmission that is greater than 90% at 656.8 nm. This unmounted ultra-narrowband filter is coated on a 2 mm thick polished Borofloat® substrate and is 12.5 mm (± 0.1 mm) in diameter. Alluxa ultra-narrow bandpass filters have the highest transmission and narrowest bandwidths currently available. And because they are hard-coated using our innovative SIRRUS™ plasma deposition process, all Alluxa optical filters are highly durable and resistant to laser damage. Contact us for custom sizing options.