Metalorganic molecular beam epitaxy of strain-compensated InAsP/InGaAsP multi-quantum-well lasers

Abstract

Strain-compensated InAsP/InGaAsP multi-quantum-wells (MQWs) grown by metalorganic molecular beam epitaxy (MOMBE) are characterized by conventional photoluminescence (PL), micro-PL, transmission electron microscopy, and x-ray diffraction measurements and applied to fabricate 1.3 μm wavelength laser diodes. These methods reveal that there is no deterioration in the optical properties or structure of strain-compensated MQWs having up to 25 wells, which means that the critical thickness of InAsP grown by MOMBE exceeds 1000 Å. The critical conditions of strain and thickness over which misfit dislocations are generated are determined for the MQWs. The MQW lasers with ten wells (Lz=55 Å) have no misfit dislocations and have uniform threshold current densities of 0.9±0.1 kA/cm2. The maximum operating temperature Tmax of the lasers increases with increasing well number, the highest Tmax is 155 °C, which is obtained for MQW lasers with 15 wells. The lasers have no problems in terms of long-term reliability.