High-Performance 1.06-Mu M Ingaas/Gaas Double-Quantum-Well Semiconductor Lasers With Asymmetric Heterostructure Layers

High-performance 1.06-mu m InGaAs/GaAs double-quantum-well (DQW) asymmetric herero-structure semiconductor lasers have been designed, fabricated and characterized. The laser structure, grown by metal-organic chemical vapor deposition (MOCVD), mainly consists of compositionally graded p-AlxGa1-xAs upper cladding layers, a p-AlxGa1-xAs upper waveguide layer, a 1.06-mu m InGaAs/GaAs DQW active region, an un-doped In1-xGaxAsyP1-y lower waveguide layer, and compositionally graded n-doped In1-xGaxAsyP1-y lower cladding layers. Measurement results of the as-cleaved ridge waveguide (RWG) lasers with a contact ridge width of 25 mu m and different cavity lengths (900 to 2765 mu m) demonstrated state-of-the-art performances with a high internal quantum efficiency (eta(i)) of similar to 98.4% and a low internal optical loss (alpha(i)) of similar to 1.01 cm(-1) at 20 degrees C. The laser has demonstrated high characteristic temperatures of 245 K (T-0) and 663 K (T-1) from 20 to 50 degrees C, and the cavity length dependent behaviour of T-0 and T-1 has also been investigated from 20 to 80 degrees C. Furthermore, a low transparency current density (J(tr)) of 77 A/cm(2)/QW in this laser structure is obtained at 20 degrees C, which is among one of the lowest values reported so far for 1.06-mu m InGaAs/GaAs semiconductor lasers.