High-gain coupled InGaAs quantum well InAs quantum dot AlGaAs–GaAs–InGaAs–InAs heterostructure diode laser operation

Data are presented showing that a single-layer InAs quantum dot (QD) laser in the AlGaAs–GaAs–InGaAs–InAs heterostructure system is improved in gain and continuous wave (cw) room temperature operation by coupling, via tunneling, auxiliary strained-layer InGaAs quantum wells (QWs) to the single InAs QD layer to assist carrier collection and thermalization. A QW-assisted single-layer InAs QD laser, a $\mathrm{QD}+\mathrm{QW}$ laser, is demonstrated that operates cw (300 K), and at diode length 150 μm in pulsed operation exhibits gain as high as $\text{∼100\hspace{0.17em}}{\mathrm{cm}}^{\text{−1}}.$