Quasi-simultons in thermal atomic vapors

TL;DR

This paper investigates the formation of two-color soliton-like pulses, called quasi-simultons, in thermal atomic vapors, demonstrating their generation, properties, and potential for strong photon interactions with experimental and theoretical support.

Contribution

It introduces the concept of quasi-simultons in thermal vapors, showing their formation via hyperfine coherence interplay and validating the model with experiments.

Findings

Formation of sech-squared pulses less than 10 microns long.

Good agreement between experiment and hyperfine-structure-inclusive model.

Potential for strong photon-photon interactions with Rydberg dressing.

Abstract

The propagation of two-color laser fields through optically thick atomic ensembles is studied. We demonstrate how the interaction between these two fields spawns the formation of co-propagating, two-color soliton-like pulses akin to the simultons found by Konopnicki and Eberly [Phys. Rev. A 24, 2567 (1981)]. For the particular case of thermal Rb atoms, exposed to a combination of a weak cw laser field resonant on the D1 transition and a strong, sub-ns laser pulse resonant on the D2 transition, simulton formation is initiated by an interplay between the 5s_{1/2} -- 5p_{1/2} and 5s_{1/2} -- 5p_{3/2} coherences which amplifies the D1 field at the arrival of the D2 pulse producing sech-squared pulse with a length of less than 10 microns. This amplification is demonstrated in a time-resolved measurement of the light transmitted through a thin thermal cell. We find good agreement between experiment and a model that includes the hyperfine structure of the relevant levels. With the addition of Rydberg dressing, quasi-simultons offer interesting prospects for strong photon-photon interactions in a robust environment.