Optical filter and sensor system

摘要

An optical filter having a passband at least partially overlapping with a wavelength range of 800 nm to 1100 nm is provided. The optical filter includes a filter stack formed of hydrogenated silicon layers and lower-refractive index layers stacked in alternation. The hydrogenated silicon layers each have a refractive index of greater than 3 over the wavelength range of 800 nm to 1100 nm and an extinction coefficient of less than 0.0005 over the wavelength range of 800 nm to 1100 nm.

主权项

1. An optical filter, comprising:
a filter stack comprising:
a plurality of thin film hydrogenated silicon layers, wherein the plurality of thin film hydrogenated silicon layers have a refractive index of greater than 3 over a wavelength range of 800 nm to 1100 nm; anda plurality of thin film dielectric lower-refractive-index layers, wherein the plurality of thin film dielectric lower-refractive-index layers have a refractive index of less than 3 over the wavelength range of 800 nm to 1100 nm, and wherein the plurality of thin film dielectric lower-refractive-index layers alternate, in a one-to-one ratio, with the plurality of thin film hydrogenated silicon layers; and wherein the optical filter has exhibits interference that creates a passband at least partially overlapping with the wavelength range of 800 nm to 1100 nm,
wherein the passband has a center wavelength that shifts by less than 20 nm in magnitude with a change in an incidence angle between 0° to 30°.