Carrier lifetime and modulation bandwidth of a quantum well AlGaAs/InGaP/GaAs/InGaAs transistor laser

Abstract

A quantum well (160 Å) transistor laser with a 400 μm cavity length that achieves the large 3 dB modulation bandwidth of 13.5 GHz is described. The fast base recombination (transport determined, τ BL < 10 ps) permits improvement of the carrier-photon damping ratio (>1 / √2), resulting in a resonant peak magnitude of unity and consequently a resonance frequency of ∼0 GHz (no peak) in the small-signal response. Quantum well band filling and bandwidth saturation are observed on the ground state (λ = 1000 nm), and increase with operation on the first excited state (λ = 980 nm). © 2006 American Institute of Physics.