Study of Rydberg blockade mediated optical non-linearity in thermal vapor using optical heterodyne detection technique

TL;DR

This paper demonstrates Rydberg blockade-induced optical non-linearity in thermal vapor using optical heterodyne detection, showing potential for single-photon sources and strong non-linear optical effects.

Contribution

It introduces a novel measurement of Rydberg blockade effects in thermal vapor using optical heterodyne detection, with experimental validation of blockade radius and dispersion suppression.

Findings

Blockade radius measured at about 2.2 μm.

Density-dependent suppression of dispersion peak observed.

Potential for single-photon source development in thermal vapor.

Abstract

We demonstrate the phenomenon of blockade in two-photon excitations to the Rydberg state in thermal vapor. A technique based on optical heterodyne is used to measure the dispersion of a probe beam far off resonant to the D2 line of rubidium in the presence of a strong laser beam that couples to the Rydberg state via two-photon resonance. Density dependent suppression of the dispersion peak is observed while coupling to the Rydberg state with principal quantum number, n = 60. The experimental observation is explained using the phenomenon of Rydberg blockade. The blockade radius is measured to be about 2.2 {\mu}m which is consistent with the scaling due to the Doppler width of 2-photon resonance in thermal vapor. Our result promises the realization of single photon source and strong single photon non-linearity based on Rydberg blockade in thermal vapor.