Ultralow-threshold electrically pumped quantum-dot photonic-crystal nanocavity laser

摘要

Efficient, low threshold, and compact semiconductor laser sources are beinginvestigated for many applications in high-speed communications, informationprocessing, and optical interconnects. The best edge-emitting and verticalcavity surface-emitting lasers (VCSELs) have thresholds on the order of 100muA[1,2] but dissipate too much power to be practical for many applications,particularly optical interconnects[3]. Optically pumped photonic crystal (PC)nanocavity lasers represent the state of the art in low-threshold lasers[4,5];however, in order to be practical, techniques to electrically pump thesestructures must be developed. Here we demonstrate a quantum dot photoniccrystal nanocavity laser in gallium arsenide pumped by a lateral p-i-n junctionformed by ion implantation. Continuous wave lasing is observed at temperaturesup to 150 K. Thresholds of only 181 nA at 50 K and 287 nA at 150 K are observed- the lowest thresholds ever observed in any type of electrically pumped laser.