Laser interferometry based on atomic coherence

TL;DR

This paper introduces a novel laser interferometry technique using atomic coherence in a Cs vapor cell, enabling interference between independent lasers of different wavelengths, with potential applications in phase locking.

Contribution

The work presents a new interferometry method leveraging atomic coherence that allows interference of lasers with orthogonal polarizations and different wavelengths.

Findings

Interference can be tuned from constructive to destructive.

Interference occurs even with orthogonal polarizations.

Potential for phase locking of independent lasers.

Abstract

We demonstrate laser interferometry based on phase difference between the two arms of the interferometer. The experiments are done with a Cs atomic vapor cell at room temperature and use atomic coherence. The interference can be tuned from constructive to destructive by tuning the relative phase between the two arms. It is similar to the Michelson interferometer, but differs in the important aspect of allowing interference when the polarizations in the two arms are orthogonal. This would be a novel method for interfering two independent lasers, which even can allow interfering two independent lasers of completely different wavelengths---such as of UV and IR---and also possibly phase lock them.