Crossover from Electromagnetically Induced Transparency to Autler-Townes Splitting in Open V-Type Molecular Systems

TL;DR

This paper explores the transition between electromagnetically induced transparency and Autler-Townes splitting in open V-type molecular systems, revealing conditions under which EIT occurs or is suppressed, with implications for hot and cold molecules.

Contribution

It provides analytical formulas for EIT conditions and transparency window widths, and clarifies the EIT-ATS crossover in open V-type molecular systems, supported by experimental agreement.

Findings

EIT occurs in hot molecules but not in cold molecules.

A crossover from EIT to ATS exists for hot molecules.

EIT can occur in counter-propagating configurations for hot molecules.

Abstract

We investigate electromagnetically induced transparency (EIT) and Autler-Townes splitting(ATS) in an open V-type molecular system. Through detailed analytical calculations on the absorption spectrum of probe laser field by using residue theorem and spectrum decomposition, we find that EIT may occur and there exists a crossover from EIT to ATS (i.e. EIT-ATS crossover) for hot molecules. However, there is no EIT and hence no EIT-ATS crossover for cold molecules. Furthermore, we prove that for hot molecules EIT is allowed even for a counter-propagating configuration. We provide explicit formulas of EIT conditions and widths of EIT transparency windows of probe field when hot molecules work in co-propagating and counter-propagating configurations, respectively. Our theoretical result agrees well with the recent experimental one reported by Lazoudis et al. [Phys. Rev. A 83, 063419 (2011)].