RADIATIVE COUPLING AND DECAY PROPERTIES OF QUANTUM CONFINED SEMICONDUCTORS

Abstract

Several contemporary research topics on the subject of light-matter coupling are addressed. Through a variety of experimental methods, the emissive and carrier correlation properties of both quantum dots (QD) and quantum wells (QW) are explored.The radiative decay properties of self-assembled indium arsenide (InAs) quantum dots grown by molecular beam epitaxy (MBE) are discussed. The measurement of radiative lifetime is used to determine dipole moment. In addition, evidence is presented of radiative lifetime reduction for quasi-resonant and strictly resonant time-resolved measurements. This lessening is attributed to carrier correlations which exist during resonant excitation but that are not present during above-band pumping. The data do not support the assertion that the shorter radiative lifetime is caused by a superradiant effect.MBE-grown Fibonacci sequence QWs exhibiting novel polaritonic properties are also introduced. These quasiperiodic structures stand apart from periodic structures in that they possess nonperiodic long-range order. Subsequent investigation of nonlinear reflectivity in the quasiperiodic structure showed excellent agreement with theoretical predictions. Of particular interest is the narrow deep dip close to the heavy hole resonance as well as the valley between the heavy hole and light hole resonance positions.