TWO-DIMENSIONAL PHOTONIC CRYSTAL SURFACE-EMITTING LASER
A two-dimensional photonic crystal surface-emitting laser having a photonic crystal in which a photonic crystal periodic structure is located in or near an active layer (first medium) which emits light when carriers are injected thereto. The photonic crystal periodic structure comprises a second medium with a refractive index different from that of the active layer scattered in two-dimensional periodic array. The photonic crystal periodic structure is of a square lattice structure or a triangular lattice structure which has translation symmetry but does not have rotation symmetry. Alternatively, the photonic crystal periodic structure is of a square lattice structure or a rectangular lattice structure which is classified into pl, pm, pg or cm according to the two-dimensional pattern classification method.
It is the most desirable that the lattice structure is composed of triangular lattice points.