High-speed GaAs/AlGaAs multiple-quantum-well lasers: design and characterization

The authors have developed GaAs/AlGaAs multiple-quantum-well (MQW) lasers with direct modulation bandwidths of 16 GHz. The devices utilize a compact vertical layer structure which also makes them particularly suitable for integration. The theoretical calculations leading to this optimized design as well as the DC and high-frequency characteristics of the lasers are discussed. A 3-dB electrical modulation bandwidth of 16 GHz was achieved at 90-mA pulsed bias in a 4- mu m*200- mu m device. The slope of the plot of the resonance frequency versus the square root of the optical power yielded values of dg/dn ranging between 4*10/sup -16/ and 7*10/sup -16/ cm/sup 2/ for short-cavity-length and narrow-mesa-width lasers.