Single-Mode Laser Oscillation in Semiconductor Gain Photonic Crystals

A theory is presented for calculating the intensity of light emitted from the two-dimensional photonic crystal with cylindrical gain rods at their lattice points. The results obtained theoretically demonstrate for the first time that an oscillation occurs in this kind of photonic crystal laser with no ordinary external cavities, and, moreover, that it occurs in the single mode in a certain frequency range studied. The light is found to have a strong intensity toward the direction of the M-point in the Brillouin zone.