Imaging of induced surface charge distribution effects in glass vapor cells used for Rydberg atom-based sensors

TL;DR

This study uses fluorescence imaging to visualize how surface charge distributions on glass vapor cells affect Rydberg atom-based sensors, revealing that visible light induces localized charges impacting sensor performance.

Contribution

The paper introduces a fluorescence imaging method to map surface charge effects in vapor cells and demonstrates how specific wavelengths influence charge induction, affecting Rydberg electrometry.

Findings

Visible light induces localized surface charges on glass walls.

Three-photon Rydberg EIT with near-infrared lasers shows no charge induction.

Surface charge effects can be positive and disrupt sensor accuracy.

Abstract

We demonstrate the imaging of localized surface electric (E) field effects on the atomic spectrum in a vapor cell used in Rydberg atom-based sensors. These surface E-fields can result from an induced electric charge distribution on the surface. Induced surface charge distributions can dramatically perturb the atomic spectrum, hence degrading the ability to perform electrometry. These effects become pronounced near the walls of the vapor cell, posing challenges for vapor cell miniaturization. Using a fluorescence imaging technique, we investigate the effects of surface charge on the atomic spectrum generated with electromagnetically induced transparency (EIT). Our results reveal that visible light (480 nm and 511 nm), i.e., the coupling laser used in two-photon Rydberg EIT schemes, generates localized patches of charge or dipoles where this light interacts with the glass walls of the vapor cell, while a three-photon Rydberg EIT scheme using only near-infrared wavelength lasers shows no measurable field induction. Additionally, imaging in a vacuum chamber where a glass plate is placed between large electrodes confirms that the induced charge is positive. We further validate these findings by studying the photoelectric effect with broadband light during EIT and impedance measurements. These results demonstrate the power of the fluorescence imaging technique to study localized E-field distributions in vapor cells and to target the photoelectric effect of the alkali-exposed glass of vapor cells as a major disruptor in Rydberg atom-based sensors.