MULTILAYER OPTICAL BANDPASS FILTER Russian patent published in 2015 - IPC G02B5/28 

FIELD: physics.

SUBSTANCE: filter comprises a symmetrical structure of alternating dielectric layers with a high and a low refraction index, which forms a system of single-layer resonators separated from each other and from the surrounding space by adjacent multilayer mirrors. The dielectric layer of each resonator has optical thickness of λ/2, and each dielectric layer in each multilayer mirror has optical thickness of λ/4, where λ is wavelength at centre frequency of the transmission band. The dielectric layers in the mirrors are made of at least three materials with different refraction indices and the reflectance of the mirrors decreases with increase in the distance of the mirror from the centre of the structure.

EFFECT: reduced non-uniformity of the transmission coefficient of light in the transmission band of a filter and reduced losses.

2 cl, 3 dwg