Scanning near-field optical spectroscopy and imaging using nanofabricated probes

Abstract
We have designed and constructed a scanning near-field optical microscopy (SNOM) system which is based on batch-fabricated aperture probes fabricated using micromachining and direct-write electron-beam lithography. The aperture is situated at the hollow tip apex of a modified silicon nitride atomic force microscope (AFM) cantilever. The SNOM/AFM probes are used both for excitation and collection of luminescence due to their excellent optical efficiency. The integration of a cantilever with the aperture allows better control of the aperture–sample distance and also results in considerable simplification of the SNOM system. Using this system, we have obtained near-field luminescence spectra and imaging of GaAs/AlGaAs quantum wires and wells, and have demonstrated spectrally resolved luminescence imaging with a spatial resolution of ∼50 nm.