Propagation processing of short pulses in Rydberg exciton medium under blockade conditions

Abstract

Propagation of short pulses through Cu$_2$O crystal containing Rydberg excitons is studied with the use of density matrix formalism and FDTD method. Saturation effects related to the so-called Rydberg blockade are studied extensively, exploring not only reduction of absorption (bleaching) but also power-dependent changes of the dispersive properties of the medium. The role of exciton lifetime and coherent population oscillations in the dynamics of the system is investigated. A pump-probe setup with two pulses is also studied, showing good agreement with recent experimental studies.

Figures (13)

• Figure 1: Energy level schematic of the considered system
• Figure 2: Geometry of the considered system
• Figure 3: a) absorption coefficient of Cu$_2$O crystal, exhibiting multiple excitonic peaks. Dashed line represents a Gaussian laser pulse. b) zoom on a single exciton resonance ($n$=3); numerically calculated frequency spectra of incident and transmitted field, as well as medium susceptibility are shown.
• Figure 4: The transmission spectrum of the crystal in a frequency range of a single excitonic resonance, as a function of crystal thickness.
• Figure 5: Spatio-temporal distribution of the field illustrating the propagation of a single pulse through $L=10$$\mu$m crystal (marked by white, dashed lines).