Comparison of 1.3-µm AlGaInAs/AlGaInAs Strain-Compensated Multiple-Quantum-Well Laser Diodes with/without GaInAsP and AlGaInAs Graded-Composition Layers

In this letter, we have fabricated the 1.3-mum Al0.20Ga0.11In0.69As/Al0.30Ga0.26In0.44As strain-compensated multiple-quantum-well laser diodes (LDs) with the GaInAsP and AlGaInAs graded-composition layers above the upper and below the lower cladding layers, respectively. This new LD structure exhibits a lower threshold current of 9mA, a higher characteristic temperature of 80 K between 20 and 70degreesC, a little red-shift rate of 0.4 nm/degreesC and a higher relaxation frequency of 8.14 GHz at 80 mA and 20degreesC. Without coupling loss and damping factor, the 3 dB bandwidth of 13.1 GHz can be achieved. These characteristics are better than those LDs without the graded-composition layers.