11 June 2002 Intersubband relaxation time for excitons in the n=2 subbands of GaAs quantum wells
Author Affiliations +
Proceedings Volume 4643, Ultrafast Phenomena in Semiconductors VI; (2002) https://doi.org/10.1117/12.470411
Event: Symposium on Integrated Optoelectronic Devices, 2002, San Jose, California, United States
Abstract
We resonantly excite the n=2 excitons at 8 K in 13 nm and 17.5 nm GaAs quantum wells using 0.5 ps pulses from a Ti-Sapphire laser and perform four wave mixing (FWM) measurements. The exciton dephasing time is deduced by fitting the FWM spectra to a numerical solution of the optical Bloch equations for the excitonic resonance. The finite pulse width and presence of small inhomogeneous broadening are taken into account. The homogeneous linewidth thus obtained at different low excitation intensities has a linear dependence on the intensity. The zero intensity intercept is essentially governed by the n=2 exciton lifetime due to intersubband relaxation, the pure transverse dephasing contribution being relatively less important. We deduce the exciton lifetime to be 0.9 ps and 2.6 ps for the 13 nm and 17.5 nm QWs, respectively.
© (2002) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Bipul Pal, Bipul Pal, Arvind S. Vengurlekar, Arvind S. Vengurlekar, "Intersubband relaxation time for excitons in the n=2 subbands of GaAs quantum wells", Proc. SPIE 4643, Ultrafast Phenomena in Semiconductors VI, (11 June 2002); doi: 10.1117/12.470411; https://doi.org/10.1117/12.470411
PROCEEDINGS
8 PAGES


SHARE
Back to Top