A hybrid polarization-selective atomic sensor for radio-frequency field detection with a passive resonant-cavity field amplifier

TL;DR

This paper introduces a hybrid atomic sensor combining a passive resonator with an atomic vapor cell to achieve high-sensitivity, polarization-selective radio-frequency field detection with intrinsic amplification, demonstrated in the C-band.

Contribution

The work presents a novel hybrid sensor design that integrates a passive resonator with atomic vapor for enhanced RF detection and polarization selectivity, with experimental validation.

Findings

Achieved 24 dB field amplification in sensitivity.

Demonstrated polarization-selective detection of RF fields.

Validated experimental results with simulations.

Abstract

We present a hybrid atomic sensor that realizes radio-frequency electric field detection with intrinsic field amplification and polarization selectivity for robust high-sensitivity field measurement. The hybrid sensor incorporates a passive resonator element integrated with an atomic vapor cell that provides amplification and polarization selectivity for detection of incident radio-frequency fields. The amplified intra-cavity radio-frequency field is measured by atoms using a quantum-optical readout of AC level shifts of field-sensitive atomic Rydberg states. In our experimental demonstration, we employ a split field-enhancement resonator embedded in a rubidium vapor cell to amplify and detect C-band radio-frequency fields. We observe a field amplification equivalent to a 24 dB gain in intensity sensitivity. The spatial profile of the resonant field mode inside the field-enhancement cavity is characterized. The resonant field modes only couple with a well-defined polarization component of the incident field, allowing us to measure the polarization of the incident field in a robust fashion. Measured field enhancement factors, polarization-selectivity performance, and field distributions for the hybrid sensor are in good agreement with simulations. Applications of hybrid atomic sensors in ultra-weak radio-frequency detection and advanced measurement capabilities are discussed.