Near-field photoreflectance spectroscopy of quantum well structures

摘要

We present near-field photoreflectance (NPR) spectroscopic studies of GaAs/Al_(0.3)Ga_(0.7)As quantum well structures using a near-field scanning optical microscope with either an uncoated or a metal-coated tapered optical fiber probe. The NPR method provides advantages over conventional optical microscopic ones: (i) higher signal-to-noise ratio, (ii) lower temperature-sensitivity of the signal, and (iii) more information about higher electronic energy states. We also discuss the feasibility of a imaging with high resolution and contrast by using the NPR method.