Effect of buffer gas on electromagnetically induced transparency in a ladder system using thermal rubidium vapor

TL;DR

This paper demonstrates the first observation of electromagnetically induced transparency in a ladder system with a buffer gas, revealing how buffer gases influence EIT line shapes and broadening in thermal rubidium vapor.

Contribution

It provides the first experimental analysis of buffer gas effects on EIT in a ladder system, highlighting the impact on line broadening and transparency features.

Findings

Buffer gas causes additional broadening of 32 MHz in EIT lines.

Strong transparency persists when Rabi frequency exceeds collisional dephasing.

Measured cross section for Rb-Ne collision is (7 +/- 1) x 10^-19 m^2.

Abstract

We report on the first observation of electromagnetically induced transparency (EIT) in a ladder system in the presence of a buffer gas. In particular we study the 5S1/2 - 5P3/2 - 5D5/2 transition in thermal rubidium vapor with a neon buffer gas at a pressure of 6 Torr. In contrast to the line narrowing effect of buffer gas on {\Lambda}-systems we show that the presence of the buffer gas leads to an additional broadening of (32 +/- 5) MHz, which suggests a cross section for Rb(5D5/2)-Ne of {\sigma} = (7 +/- 1) x 10-19 m2. However, in the limit where the coupling Rabi frequency is larger than k the collisional dephasing a strong transparency feature can still be observed.