Experimental observation of whispering gallery modes in sector disk lasers

The existence of the whispering gallery modes in a sector disk resonator has been demonstrated theoretically and experimentally observed in a disk, half-disk, and quarter-disk semiconductor lasers. The half-disk and quarter-disk lasers are fabricated from 285μm diameter disks emitted near 2.13μm at room temperature with continuous wave threshold currents of 55–60mA. Mode spacing in emission spectra of the half-disk lasers was the same as for the whole disk and doubled for the quarter disk as expected from the theoretical analysis. Half-disk lasers emit two parallel beams from the cleaved facet, while the two output beams are perpendicular in quarter-disk devices.