Observation of CPT for the ground hyperfine interval in $^{133}$Cs

TL;DR

This paper demonstrates a CPT-based technique to measure the ground hyperfine interval in $^{133}$Cs using a compact diode laser system, with potential applications in satellite atomic clocks.

Contribution

It introduces a simplified, fiber-coupled CPT setup for precise hyperfine interval measurement in cesium atoms.

Findings

Successful measurement of the hyperfine interval using CPT

Use of a single diode laser with EOM for phase coherence

Potential for compact, satellite-compatible atomic clocks

Abstract

We use the technique of coherent population trapping (CPT) to access the ground hyperfine interval (clock transition) in $^{133}$Cs. The probe and control beams required for CPT are obtained from a single compact diode laser system. The phase coherence between the beams, whose frequency difference is the clock frequency, is obtained by frequency modulating the laser with an electro-optic modulator (EOM). The EOM is fiber coupled and hence does not require alignment, and the atoms are contained in a vapor cell. Both of these should prove advantageous for potential use as atomic clocks in satellites.