Patent ID: 7535946

Claim:
A structure comprising: a photonic crystal layer including a first member having a first refractive index n 1 in which a plurality of holes are formed so as to be periodically arranged; a second member adjoining the photonic crystal layer, the second member having a second refractive index n 2 lower than the first refractive index; and a third member disposed on the first member, the third member having a third refractive index n 3 higher than 1.0 and lower than the first refractive index n 1 , wherein the first refractive index n 1 and the second refractive index n 2 satisfy the relationship (n 1 −n 2 )/n 1 ≦0.10, and the holes of the photonic crystal layer have a depth in the range of 20% to 80% of the thickness of the first member.