Chapter 2 Spatially and temporally resolved near-field scanning optical microscopy studies of semiconductor quantum wires

Abstract

Publisher Summary This chapter focuses on the near-field scanning optical microscopy studies of semiconductor quantum wires. Most optical experiments are performed under far-field conditions in which diffraction determines the minimum diameter of the optical beam at the nanostructure. The spatial resolution of such optical studies is limited to the wavelength of light as predicted by classical theories of diffraction. The use of experimental techniques with a spatial resolution in the nanometer range is thus crucial for optical studies of single nanostructures. Until now, methods based on the injection of electrons, such as cathodoluminescence spectroscopy, have been used for monitoring the local properties of nanostructures on submicron length scales. In addition, the limited spatial resolution makes it difficult to resolve the transport of excitations and/or carriers, often occurring on mesoscopic length scales in the submicron range. However, the initial energy distribution of carriers, its relaxation toward quasi-equilibrium, and the transport of carriers in the nanostructure are difficult to control in such measurements.