Low-threshold lasing in novel microdisk geometries

We have fabricated arrays of semiconductor microdisks with diameters from 3.5-9 mu m using wet chemical etching in combination with epitaxial lift-off and metallic bonding techniques, The microdisks are supported on glass for higher optical confinement and to allow novel annular geometries. The optically pumped microdisks have high-Q (>2000) modes, low-pump thresholds (<20 mu W) and multimode lasing at liquid nitrogen temperatures, Successive modes are excited by temperature tuning the bandgap.