The luminescence of GaAs quantum-well-based microstructures was invest
igated with a scanning near-field optical microscope at different ambi
ent temperatures. The scanning tip was fabricated from an optical fibe
r. The excitation laser beam (514 nm, 100-300 mW) was focused onto the
opposite end of the fiber. The carrier distribution in the sample was
investigated using the high-energy tail of the luminescence peak. Tem
perature fits show no overheating of the sample despite the expected h
igh temperatures of the tip. (C) 1998 American Institute of Physics.