Detection of ultra-high resonance contrast in vapor cell atomic clocks

TL;DR

This paper introduces a new detection method for vapor cell atomic clocks that achieves ultra-high resonance contrast and significantly improves signal precision, SNR, and frequency stability.

Contribution

The paper presents a novel detection scheme that surpasses previous methods in resonance contrast and stability for vapor cell atomic clocks.

Findings

Resonance contrast above 90% achieved

Frequency stability improved by an order of magnitude

Density effects influence linewidth and peak splitting

Abstract

We propose and demonstrate a novel detection scheme of clock signals and obtain an ultra-high resonance contrast above 90%. The precision of the signal's detection and the signal-to-noise ratio (SNR) of atomic clock signal is improved remarkably. The frequency stability in terms of Allan deviation has been improved by an order for the new detection under the equivalent conditions. We also investigate density effect which produces the splitting of the transmission peak and consequently a narrower linewidth of Ramsey fringes.