Engineering laser gain spectrum using electronic vertically coupled InAs-GaAs quantum dots

Continuous large-broad laser gain spectra near 1.3 mu m are obtained using an active region of electronic vertically coupled (EVC) InAs-GaAs quantum dots (QDs). A wide continuous electroluminescence spectrum, unlike that from conventional uncoupled InAs QD lasers, was obtained around 230 nm (below threshold) with a narrow lasing spectrum. An internal differential quantum efficiency as high as 90%, a maximum measured external differential efficiency of 73% for a stripe-length of L = 1 mm, and a threshold current density for zero total optical loss as low as 7 A/cm(2) per QD layer were achieved.