Slow light based on quantum effects in quantum wells and quantum dots

This is a detailed study of slow light based on quantum effects in semiconductor nanostructures. We propose to implement an optical buffer using semiconductor quantum dots and quantum wells based on coherent population oscillation and spin related electromagnetically induced transparency. We identify different pump-and-probe schemes and develop comprehensive theoretical models which include important physical mechanisms in semiconductors. Semiconductors have unique properties which are inaccessible to other slow light media, and these enable the possibilities of controlling the semiconductor-based optical buffer in addition to the optical method. We investigate how to electrically control group index (slowdown factor) in quantum dots by using reverse bias voltage and forward injection current. We also develop a model to use the anisotropy of the light-hole exciton to vary the slowdown factor via two different mechanisms (coherent population oscillation and spin related electromagnetically induced transparency). Finally, we propose an idea to use the strain to control the spin relaxation time in semiconductors, which can help spin-dependent slow light in semiconductors. This research shows that the semiconductor is a promising candidate to demonstrate an optical buffer and can provide more flexible control than other slow light materials.