Abstract

The experiments described here use nonlinear, time-resolved, near field scanning optical microscopy (NSOM¹) techniques to study the local carrier dynamics and spatial distributions in GaAs microdisks. GaAs quantum wells in the plane of the microdisk provide a gain material for microlasers based on the whispering-gallery modes propagating around the edge of the microdisk . We are exploring the carrier density regime required for lasing. What are the energy relaxation times and spatial diffusion lengths near the microdisk edge? How do these properties vary with surface treatment and carrier densities? These questions can best be answered using the high spatial resolution provided by NSOM and the temporal resolution of short excitation and probe pulses tuned to frequencies near the GaAs bandedge.

© 1994 Optical Society of America