Optical near-field response of semiconductor quantum dots

The near-field response of optically excited semiconductor quantum dots is theoretically investigated for the collection and illumination mode of a scanning near-field optical microscope. The study includes resolution, spectral line shape, and field distributions of single and interacting dots. It is shown that in contrast to near-field excitation of molecules with large dipole moments, the line shape and position of typical semiconductor quantum dots can be determined without a disturbance if realistic values for the intrinsic linewidth are assumed. The comparison of regular and irregular quantum-dot distributions yields characteristic signatures for disordered arrays, necessary to understand the optical response of realistic semiconductor quantum dot samples.