Broadband Rydberg Atom-Based Electric-Field Probe: From Self-Calibrated Measurements to Sub-Wavelength Imaging

TL;DR

This paper introduces a novel, broadband, self-calibrating electric-field probe based on Rydberg atoms that enables direct SI-traceable measurements and sub-wavelength imaging across a wide frequency range.

Contribution

The authors develop a new Rydberg atom-based E-field measurement technique that is broadband, self-calibrating, and capable of sub-wavelength imaging, advancing current RF sensing methods.

Findings

Effective measurement of E-fields from 1 GHz to 500 GHz

Validation through numerical simulations and far-field calculations

Potential for compact, traceable, and high-resolution E-field imaging

Abstract

We discuss a fundamentally new approach for the measurement of electric (E) fields that will lead to the development of a broadband, direct SI-traceable, compact, self-calibrating E-field probe (sensor). This approach is based on the interaction of radio frequency (RF) fields with alkali atoms excited to Rydberg states. The RF field causes an energy splitting of the Rydberg states via the Autler-Townes effect and we detect the splitting via electromagnetically induced transparency (EIT). In effect, alkali atoms placed in a vapor cell act like an RF-to-optical transducer, converting an RF E-field strength measurement to an optical frequency measurement. We demonstrate the broadband nature of this approach by showing that one small vapor cell can be used to measure E-field strengths over a wide range of frequencies: 1 GHz to 500 GHz. The technique is validated by comparing experimental data to both numerical simulations and far-field calculations for various frequencies. We also discuss various applications, including: a direct traceable measurement, the ability to measure both weak and strong field strengths, compact form factors of the probe, and sub-wavelength imaging and field mapping.