Lasing in optically pumped Ga(NAsP)/GaP heterostructures

摘要

We experimentally investigate the characteristics of light emission of optically excited Ga(NAsP) multiple quantum-well structures grown pseudomorphically on a GaP substrate by metal-organic vapor-phase epitaxy. The emission power as a function of excitation power shows at temperatures from 15 to 200 K a clear threshold after excitation with short laser pulses. The emission spectra become narrow at threshold and shift to higher energies. A well defined mode structure is observed above threshold. Complementary, quasi-steady-state gain measurements using the stripe-length method yield positive modal gain values of up to 10 cm~(-1) at room temperature, thus validating that the structures show laser action.