Study of lin||lin CPT for application in vapour cell atomic clocks

TL;DR

This paper investigates the use of lin||lin CPT with a modulated VCSEL in vapour cell atomic clocks, analyzing resonance characteristics and demonstrating potential for high stability in compact systems.

Contribution

It provides a detailed evaluation of lin||lin CPT in vapour cell clocks and shows the feasibility of achieving high stability with a compact, modulated VCSEL system.

Findings

Resonance shape and signal-to-noise ratio depend on laser detuning and magnetic field.

A stability of 6×10^{-12} τ^{-1/2} is achievable with a compact setup.

Use of a modulated VCSEL enhances system stability.

Abstract

We evaluate the use of Coherent Population Trapping (CPT) excited with parallely polarized laser fields in vapour cell atomic clocks. We study the resonance shape, the discriminator slope and signal-to-noise ratio as a function of relevant parameters such as the laser frequency detuning and the applied magnetic field. We show that a stability of $6 \cdot 10^{-12}$ $\tau^{-1/2}$ may be reached in a compact system using a modulated VCSEL.