Room-temperature 2-D photonic bandgap single defect laser

Our photonic bandgap single defect laser structure is shown. For an active medium, six strain compensated InGaAsP quantum wells are employed because of the relatively small surface recombination velocity. To realize a mechanically-robust structure with good thermal properties, the InGaAsP layer was fused with the AlAs layer on top of a GaAs wafer. For optical confinement in the vertical direction, the top AlAs is wet-oxidized. After electron-beam lithography, the AlAs layer is etched by chemically-assisted ion-beam etching. The etched triangular lattice patterns form 2-D photonic bandgap cavities of various sizes having periodicity of 450 nm. The diameter of holes is 270 nm. The thickness of active layer sandwiched between air and the wet-oxidized AlAs layer is smaller than the 1/2 wavelength to obtain a single mode condition. The finished photonic bandgap cavity is optically pumped with a 980-nm diode laser beam focused to approximately 4 mm in diameter.