Two-dimensional square lattice photonic crystal slab single defect laser

We study a square lattice photonic crystal slab single defect. Cavity modes and Q factors of a free-standing square lattice photonic crystal slab single defect is calculated by the 3D finite-difference time-domain method. Usually, there exist two TE resonant modes, degenerate dipole modes and a nondegenerate quadrupole mode, in a single defect square lattice air-hole structure. The active material of the photonic crystal lasers is six strain-compensated InGaAsP quantum wells.