Spatially structured optical effects in semiconductor quantum dots via biexciton coherence

Abstract

In this paper, we study the spatially structured optical effects that occur when weak laser lights interact with coherently prepared semiconductor quantum dots (SQDs). Initially, the SQD is prepared in a coherent superposition of the lower exciton states. By utilizing two weak optical vortex fields that couple to a biexciton state, we observe spatially dependent effects of the absorption of probe fields. Using the well-established Maxwell–Bloch equations, we analyze the generation of composite optical vortex beams within this system. Our investigation revolves around the formation of different types of spatially dependent beams, exploring their properties and characteristics. Additionally, the transfer of optical vortices through the parametric generation process is examined, for the case where only one vortex beam is present at the beginning of the medium. This study provides insights into the spatially structured optical phenomena in coherently prepared SQDs and contributes to the understanding of light–matter interactions in such systems.