REFLECTANCE AND PHOTOMODULATED REFLECTANCE STUDIES OF AN INGAAS GAAS/ALGAAS VERTICAL-CAVITY SURFACE-EMITTING LASER STRUCTURE UNDER HYDROSTATIC-PRESSURE/

An InGaAs/GaAs/AlGaAs vertical-cavity surface-emitting laser structure has been studied by conventional reflectance (R) and photomodulated r eflectance (PR) spectroscopies at room temperature and at different hy drostatic pressures up to 1.24 GPa. A clear cavity-mode signal is obse rved in both PR and R spectra, whereas the quantum-well groundstate ex citon signal is observed only in the PR spectra. The PR spectra also s how a strong resonance of the two signals at the highest pressure. The pressure dependences of the energies of the exciton and the cavity mo de were determined to be 92 meV/GPa and 15 meV/GPa, respectively. (C) 1998 Elsevier Science Ltd. All rights reserved.