OBSERVATION OF MULTIPLE RESONANCE FREQUENCIES IN STRIPE GEOMETRY INGAAS INGAASP/INP PSEUDOMORPHIC QUANTUM-WELL LASERS/

Intensity fluctuation noise in strained InGaAs/InP multiquantum-well l asers are analyzed in both ridge guided and broad-area gain-guided str uctures. A single resonance peak is observed in the noise spectrum for the ridge guided laser, as expected. However, the noise spectrum for the broad-area lasers shows multiple (approximately 2-5) resonance pea ks, distinctly spaced, from approximately 2 to approximately 5 GHz. Co mbining with near-field measurements, the experiments show that these peaks originate from lasing filaments having significantly nonuniform optical power. We also determined the resonance frequency of the singl e-mode laser from both small-signal modulation and turn-on relaxation oscillation measurements, and found the results to be consistent with the measured peak noise frequency.