Patent ID: 7187050

Claim:
An optical sensor comprising: a photo-detection element with a light absorption layer formed in a surface of said element; and a photonic crystal lens formed on the surface of said photo-detection element; wherein said photonic crystal lens comprises: a plurality of layers of a first photonic crystal made of a first glass and having a periodically arranged glass pattern; and a plurality of layers of a second photonic crystal made of a second glass, having a periodically arranged glass pattern and arranged alternating with the layers of the first photonic crystal in a stack of layers; wherein: a layer of the first photonic crystal has a first portion with a refractive index and a second portion with a refractive index that is greater than the refractive index of the first portion, the second portion of the layers of the first photonic crystal are disposed opposite to the light absorption layer, and a layer of the second photonic crystal has a refractive index that is less than the refractive index of the first portion.