PURE EFFECTS OF STRAIN IN STRAINED-LAYER MULTIPLE-QUANTUM-WELL LASERS

Pure effects of strain in strained-layer InGaAs-InGaAsP multiple-quant um-well (MQW) Fabry-Perot (FP) lasers operating at 1.5 mum region are measured separately from the quantum effects by using lasers whose act ive layer wells have the same thickness but different amounts of strai n. The gain peak wavelengths of transverse electric (TE) and transvers e magnetic (TM) modes increase and the difference between TE-and TM-mo de gain peak wavelengths also increases when compressive strain is int roduced. The differential gain coefficient and the gain saturation coe fficient of the lasers are determined by measuring relative intensity noise (RIN) spectra and are found to increase with increasing the comp ressive strain. The K factors of the lasers are also determined from t he relation between the damping constant and the resonant frequency sq uare. The factor shows slight increase when the compressive strain inc reases. The a parameter of these lasers decreases when compressive str ain is introduced.