Electrically injected 1.3-μm quantum-dot photonic-crystal surface-emitting lasers

We have fabricated electrically injected InAs/InGaAs/GaAs quantum-dot (QD) photonic-crystal (PC) surface-emitting lasers (SELs) and successfully demonstrated room-temperature lasing emissions at 1.3-μm wavelength for the first time. The PCSEL device fabrication was greatly simplified by deposition of transparent conducting layer of indium-tin-oxide over “PC slab-on-substrate” structure. The threshold current density per QD layer was as low as 50 A/cm²/layer; however, the optical output was limited to 2 mW. The band-edge lasing mode was identified and near-circular beam with narrow divergence angle less than 2° was achieved.