Sample temperature measurement in a scanning near-field optical microscope

The luminescence of GaAs quantum-well-based microstructures was investigated with a scanning near-field optical microscope at different ambient temperatures. The scanning tip was fabricated from an optical fiber. 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. Temperature fits show no overheating of the sample despite the expected high temperatures of the tip. (C) 1998 American Institute of Physics.