Continuous-frequency measurements of high-intensity microwave electric fields with atomic vapor cells

TL;DR

This paper presents a method for continuous-frequency measurement of high-intensity microwave electric fields using optical spectroscopy in atomic vapor cells, enabling absolute measurements over a broad frequency range.

Contribution

The study introduces a novel technique employing atomic vapor cells for continuous-frequency, high-intensity microwave electric field measurements with absolute calibration.

Findings

Successful measurement of microwave fields from 200 V/m to over 1 kV/m

Continuous frequency coverage of ±1 GHz around the K-band

Spectral features enable frequency-specific electric field measurements

Abstract

We demonstrate continuous-frequency electric field measurements of high-intensity microwaves via optical spectroscopy in a small atomic vapor cell. The spectroscopic response of a room-temperature rubidium atomic vapor in a glass cell is investigated and employed for absolute measurements of K$_a$-band microwave electric fields from $\sim$200 V/m to $>$1 kV/m over a continuous frequency range of $\pm $1 GHz (15% band coverage). It is established that in strong microwave fields frequency-specific spectral features allow for electric field measurements over a large continuous frequency range.