Nonlinear emission from an InGaAs/AlGaAs quantum-wire array

Gain-coupled distributed-feedback (GC-DFB) effects in a V-groove ln(0.2)Ga(0.8)As/Al0.2Ga0.8As quantum-wire (QWR) array are investigated by comparison with those in a GaAs/Al0.2Ga0.8As QWR array. Temperature-dependent photoluminescence (PL) spectra are measured for both samples, showing that the PL spectra from the QWRs are much stronger than those from the quantum wells (QWs) in the entire temperature region. Then, InGaAs/AlGaAs QWR GC-DFB lasers are fabricated by one-step metallorganic chemical vapour deposition (MOCVD) growth and characterized. As a result, strong nonlinearity in the emission spectra by optical feedback along the DFB directions is clearly observed near the threshold current, indicating that a V-groove InGaAs QWR array is a good candidate for a gain-coupled DFB laser.