Optical-lattice based Cs active clock with continual superradiant lasing signal

TL;DR

This paper presents a novel active optical clock using superradiant lasing from trapped Cs atoms in an optical lattice, achieving high stability and low uncertainty for precise timekeeping.

Contribution

It introduces a new superradiant Cs active clock with a specific magic wavelength and predicts improved stability and uncertainty levels through rigorous atomic property calculations.

Findings

Identified a magic wavelength at 1181 nm for Cs optical lattice.

Predicted fractional uncertainty of about 10^-15 for the clock frequency.

Anticipated enhanced short-term stability via bad-cavity operation mode.

Abstract

We demonstrate state-of-the-art technique of an active clock to provide a continuous superradiant lasing signal using an ensemble of trapped Cs atoms in the optical lattice. A magic wavelength of the proposed |7S1/2; F = 4, MF = 0> - |6P3/2; F = 3, MF = 0> clock transition in Cs atom is identified at 1181 nm for constructing the optical lattice. Pertinent optical lines are also found for pumping and repumping atoms from their ground states. A fractional uncertainty about 10-15 level to the clock frequency has been predicted by carrying out rigorous calculations of several atomic properties. The bad-cavity operational mode of the active clock is anticipated to improve its short-term stability remarkably by suppressing intrinsic thermal fluctuations. Thus, a composite clock system with better in both short-term and long-term stabilities can be built by combining the above proposed active clock with another high-accuracy passive optical clock.