Whispering gallery mode lasing in high quality GaAs/AlAs pillar microcavities

Abstract

We report whispering gallery mode (WGM) lasing from high quality GaAs/AlAs micropillars with embedded InAs quantum dots, under continuous optical pumping. For temperatures ranging from 5 to 100 K, simultaneous lasing from TE1,1,m WGMs is observed for pillar diameters in the 3–4 μm range. Spectral linewidths and energy shifts of the lasing modes are analyzed as a function of the pump power. Thanks to the efficient heat sinking provided by the micropillar geometry, a clear line narrowing is observed above threshold. Moreover, the lasing mode energy remains stable for pump power as large as six times the lasing threshold.