ALGAINP STRAINED MULTIPLE-QUANTUM-WELL VISIBLE LASER-DIODES (LAMBDA(L)LESS-THAN-OR-EQUAL-TO-630-NM-BAND) WITH A MULTIQUANTUM BARRIER GROWN ON MISORIENTED SUBSTRATES

We report on optimization of the misorientation angle of GaAs substrates to prepare multiple quantum wells (MQW) and multiquantum barriers (MQB) with abrupt barrier-well interfaces. We also investigate the characteristics of AlGaInP strained MQW laser diodes incorporating an MQB grown on misoriented substrates by metalorganic chemical-vapor deposition, with the aim of developing high-performance 630 nm band laser diodes. MQW and MQB with homogeneous periodicity and abrupt barrier-well interfaces were obtained using (100) GaAs substrates with a misorientation of 9-degrees toward the [011] direction. With these substrates, AlGaInP compressively strained MQW laser diodes which incorporated an MQB oscillating in the 630-nm band showed a maximum operation temperature (T(max)) 30-degrees-C higher than that for laser diodes without an MQB. A T(max) of 90-degrees-C, the highest value ever reported for 630 nm band laser diodes, was achieved with transverse-mode stabilized laser diodes having a cavity length of 350 mum. These diodes have been operating reliably for more than 3000 h under 5 mW at 50-degrees-C. By using 9-degrees misoriented substrates and introducing (Al0.1Ga0.9)0.45In0.55P into the quantum wells of the MQW, the lowest ever threshold current of 115 mA at 20-degrees-C was achieved for laser diodes oscillating at 615 nm.