Patent ID: 9448111
Filing Date: 2016-09-20
CPC Classification: F21K,F21V,F21Y,G01J,G02B

Claim Text:
1. A spectral detection device for detecting spectral components of received light, wherein said spectral detection device comprises: a variable filtering structure arranged to filter the received light and to output light with a wavelength within a predetermined wavelength range, the variable filtering structure enabling a variation of said predetermined wavelength range over time, wherein the variable filtering structure includes a first switchable photonic band gap filter having a first reflecting band of frequencies and a second switchable photonic band gap filter having a second reflecting band of frequencies different from the first reflecting band of frequencies, such that the predetermined wavelength range lies between the first and the second reflecting bands of frequencies; a light sensor arranged to detect the light output by the variable filtering structure; and an angle selection element arranged to restrict an angle of incidence for the light received by the variable filtering structure to a predetermined angle of incidence, wherein said predetermined wavelength range is adjusted by applying external stimulus to the variable filtering structure, wherein said external stimulus is selected from the group consisting of an electric field, temperature and a mechanical force.