Patent ID: 8855158

Claim:
A surface emitting laser comprising: an active layer; and a photonic crystal layer having a two-dimensionally periodic refractive index profile, wherein the photonic crystal layer has a lattice structure having two primitive translation vectors in an in-plane direction, the two primitive translation vectors having different lengths, the photonic crystal layer has members arranged at lattice points included in a unit cell of the lattice structure, the members have a shape anisotropy with respect to two directions of the two primitive translation vectors such that a distance between a barycenter of a member and an edge of the member in one direction of the two directions of the two primitive translation vectors differs a distance between a barycenter of the member and an edge of the member in the other direction of the two directions, and the members have a shape so that the coefficient of coupling along one direction of the two directions and the coefficient of coupling along the other direction of the two directions differ by a smaller amount than would occur if the members were isotropic in shape.