Aluminium-free strained-quantum-well In0.2Ga0.8As lasers employing nov
el two-stepped InGaAsP confinement layers and InGaP cladding layers on
a GaAs substrate are demonstrated for the first time. Threshold curre
nt density as low as 58 A/cm2 is obtained with broad stripe lasers. Th
is threshold current density is, to the authors' knowledge, the lowest
reported for 0.98 mum lasers grown by organic chemical vapour deposit
ion.