Low-threshold operation of hemispherical microcavity single-quantum-well lasers at 4 K

Abstract
We demonstrate low‐threshold lasing at 4 K in optically pumped hemispherical In0.2Ga0.8As single‐quantum‐well microcavities. The incident threshold pump power density is 11 kW/cm2 corresponding to an absorbed power density of about 320 W/cm2, and the measured spontaneous emission factor β is about 0.01.