2025/08/28 by Wiktor Krokosz, Jan Nowosielski, Krokosz, Wiktor +11 · 1 citation
Physics and Astronomy · Medicine · #Cold Atom Physics and Bose-Einstein Condensates #Radioactive Decay and Measurement Techniques #Allergic Rhinitis and Sensitization
paper · pdf · doi:10.48550/arxiv.2508.20698
Terahertz radiation finds an increasing number of applications, yet efficient generation and detection remain a challenge and an active area of research. In particular, the precise detection of weak and narrowband terahertz signals is notoriously difficult. Here, we employ a novel type of single-photon detector based on Rydberg atoms to both detect and calibrate a terahertz frequency comb over an octave-spanning range, yet with a MHz-level selectivity. We calibrate the intensity of the electric field of the comb against the fundamental atomic properties, while achieving the intensity (power) sensitivity down to 45.2 \mathrmfW cm-2 Hz-0.5 (1.84 \mathrmfW Hz-0.5) within a single mode of the frequency comb, all in a room-temperature operated setup. Our results elucidate the transition of terahertz frequency combs into the quantum regime, enabling high-precision and high-sensitivity spectroscopy. This breakthrough allows terahertz science to better leverage revolutionary techniques developed for optical frequency combs.