High and uniform coherence creation in Doppler broadened double lambda-like atomic system by a train of femtosecond optical pulses

TL;DR

This paper demonstrates that a train of femtosecond pulses can create high, uniform coherence in Doppler-broadened double lambda atomic systems, even with low repetition frequencies, by analyzing coherence accumulation across velocity groups.

Contribution

It introduces a method using pulse trains with low repetition frequencies to achieve high and uniform coherence in Doppler-broadened atomic systems, accounting for velocity group effects.

Findings

High coherence achieved across all velocity groups.

Low repetition frequency pulses effectively generate uniform coherence.

Coherence accumulation varies with the number of pulses.

Abstract

We present a detailed analysis of coherence creation in a four level double lambda-like atomic system using a train of ultra-short few-cycle Gaussian pulses. The effect of the Doppler broadening has been analyzed. It is possible to create high coherence across all the velocity groups in the atomic ensemble using pulses with low repetition frequency. The accumulation of coherence at different radial locations within the atomic beam cross-section as a function of the number of pulses in the train is also reported. We find that pulse train with lower repetition frequencies are able to generate high and nearly uniform coherence in a substantial part of the atomic system.