Aluminium-free GaAs/GaInAsP quantum well lasers

Al-free GaAs/GaInAsP separate-confinement-heterostructure single-quantum-well lasers are reported. The laser structure was grown by gas-source molecular beam epitaxy. A low threshold current density of 207 A/cm2 and a high characteristic temperature of 167 K were achieved for the uncoated broad-area lasers. The transparency current density was 58 A/cm2 and gain coefficient 0.039 cm μm A−1. The internal quantum efficiency and internal waveguide loss were 86% and 5.7 cm−1, respectively. The results are comparable to those obtained for GaAs/AlGaAs quantum well lasers.