Patent ID: 9658372
Date: 2017-05-23
CPC Classifications: G01J,G02B,H01L,Y10T

Claim:
1. An optical filtering structure comprising a stack of layers forming at least one first filter letting pass the wavelengths of a first spectral band and cutting off the wavelengths of a second spectral band, and a second filter adjacent to the first filter and letting pass the wavelengths of the second spectral band and cutting off the wavelengths of the first spectral band, wherein the stack of layers comprises: a plurality of dielectric layers common to the first filter and to the second filter and forming an alternation of layers of different refractive indices; n first metal layers common to the first filter and to the second filter, wherein each first metal layer comprises at least one of copper, aluminium, and silver; m second metal layers arranged only in the second filter, wherein each second metal layer comprises at least one of copper, aluminium, and silver, wherein at least one of said dielectric layers has a same thickness in the first and second filters; and wherein at least one of said dielectric layers comprises, in the first filter, a thickness different to that in the second filter, and/or wherein at least one dielectric layer is arranged only in the first or the second filter; n being an integer greater than or equal to 0, and m being an integer greater than or equal to 1.