▎ 摘　　要

NOVELTY - The optical sensor (10) has a first graphene layer (15) and a second graphene layer (17) which applies an electric field to the first layer. An insulating layer (16) is inserted between the first and second graphene layers. A first electrode pair (13,14) reads the optical voltage or the photoelectric current generated in the first sheet layer based on the light received by the optical sensor. A second electrode pair (21,22) is connected to the second sheet layer. A unit structure is formed in the graphene layers, the insulating layers, and the graphene layer. The unit structure has the periodic structure repeated twice or more by the lamination direction. The impurity concentration of the second layer is higher than that of the first sheets layer. USE - Optical sensor for imaging device (claimed). ADVANTAGE - The optical sensor enables doping controlling to a multilayer graphene layer and by which light absorption is improved. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for an imaging device. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic diagram which shows the basic composition of the optical sensor. (Drawing includes non-English language text). Optical sensor (10) First electrode pair (13,14) First graphene layer (15) Insulating layer (16) Second graphene layer (17) Second electrode pair (21,22)