arXiv subjects

Wiktor Krokosz

Publications and source records attributed to Wiktor Krokosz.

4 recordsLinked to original sources

arXiv2026

Background-free calibrated electric-field imaging with Rydberg-state fluorescence and Autler-Townes splitting

We demonstrate a spatially resolved method for imaging millimeter-wave (mmWave) electric fields using Rydberg-state fluorescence in a warm atomic vapor. By utilizing a multi-photon ladder excitation scheme, we leverage a specific decay channel that remains dark in the absence of the mmWave field, resulting in high-contrast imaging with effectively zero background. Absolute calibration of the local electric field is achieved by reconstructing the Autler-Townes splitting of the Rydberg resonance across the imaging volume. To ensure robust field extraction across a wide dynamic range--including regimes where spectral features are not fully resolved--we employ a steady-state analysis based on the Gorini-Kossakowski-Sudarshan-Lindblad (GKSL) master equation. We apply this technique to visualize standing-wave interference patterns within a vapor cell and demonstrate the ability to engineer local field distributions using structured dielectric reflectors. This approach provides a versatile and self-calibrating platform for the diagnostic imaging of high-frequency electromagnetic fields and the characterization of mmWave-optical interfaces.

physics.atom-ph↗

arXiv2025

Electric-field metrology of a terahertz frequency comb using Rydberg atoms

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 $\mathrm{fW\ cm^{-2}\ Hz^{-0.5}}$ (1.84 $\mathrm{fW\ Hz^{-0.5}}$) 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.

physics.optics↗

arXiv2024

A Rydberg atom based system for benchmarking mmWave automotive radar chips

Rydberg atomic sensors and receivers have enabled sensitive and traceable measurements of RF fields at a wide range of frequencies. Here we demonstrate the detection of electric field amplitude in the extremely high frequency (EHF) band, at $131\ \mathrm{GHz}$. In our approach we propagate the EHF field in a beam, with control over its direction and polarization at the detector using photonic waveplates. This way, we take advantage of the highest detection sensitivity, registered for collinear propagation and circular polarization. To exhibit the potential for applications in this kind of Rydberg-atom based detection, we perform test measurements on the EHF field emitted from an on-chip radar, planned to be used in automotive industry as a vital sign detector. Our work elucidates practical applications of Rydberg-atom media as well as photonic metamaterial elements.

physics.app-ph↗

arXiv2023

Beating the spectroscopic Rayleigh limit via post-processed heterodyne detection

Quantum-inspired superresolution methods surpass the Rayleigh limit in imaging, or the analogous Fourier limit in spectroscopy. This is achieved by carefully extracting the information carried in the emitted optical field by engineered measurements. An alternative to complex experimental setups is to use simple homodyne detection and customized data analysis. We experimentally investigate this method in the time-frequency domain and demonstrate the spectroscopic superresolution for two distinct types of light sources: thermal and phase-averaged coherent states. The experimental results are backed by theoretical predictions based on estimation theory.

quant-ph↗