arXiv subjects

Sebastian Borówka

Publications and source records attributed to Sebastian Borówka.

8 recordsLinked to original sources

arXiv2026

Rydberg Receivers for Space Applications

Rydberg-atom sensors convert radiofrequency, microwave and terahertz fields into optical signals with SI-traceable calibration, high sensitivity, and broad tunability. This review assesses their potential for space applications by comparing five general architectures (Autler-Townes, AC-Stark, superheterodyne, radiofrequency-to-optical conversion, and fluorescence) against space application needs. We identify promising roles in radiometry, radar, terahertz sensing, and in-orbit calibration, and outline key limitations, including shot noise, sparse terahertz transitions, and currently large Size, Weight, Power and Cost. A staged roadmap highlights which uncertainties should be resolved first and how research organisations, industry and space agencies could take the lead for the different aspects.

quant-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↗

arXiv2025

Optically-biased Rydberg microwave receiver enabled by hybrid nonlinear interferometry

The coupling of Rydberg vapour medium to both microwave and optical fields allows harnessing the merits of all-optical detection, e.g. weak disruption of the measured field and invulnerability to extremely strong fields, owing to the lack of a conventional antenna in the detector. However, the highest sensitivity in this approach is typically achieved by introducing an additional microwave field acting as a local oscillator, thereby compromising the all-optical nature of the measurement. Here we propose an alternative method, optical-bias detection, that allows truly all-optical operation, while retaining exceptional sensitivity. We tackle the issue of laser phase noise, emerging in this type of detection, via a simultaneous measurement of the laser phase noise in a nonlinear process and real-time data processing, which overall yields an improvement of $35\ \mathrm{dB}$ in terms of signal-to-noise ratio compared with the basic approach. We report the sensitivity of $176\ \mathrm{nV/cm/\sqrt{Hz}}$ and reliable operation up to $3.5\ \mathrm{mV/cm}$ of $13.9\ \mathrm{GHz}$ electric field. We also demonstrate a quadrature-amplitude modulated data transmission, underlining the capability of the system to detect quadratures of the microwave field. This approach is thus directly comparable to the state-of-the-art superheterodyne, while retaining the merits of all-optical detection.

physics.atom-ph↗

arXiv2024

Atomic-optical interferometry in fractured loops: a general solution for Rydberg radio frequency receivers

The development of novel radio frequency atomic receivers brings attention to the theoretical description of atom-light interactions in sophisticated, multilevel schemes. Of special interest, are the schemes where several interaction paths interfere with each other, bringing about the phase-sensitive measurement of detected radio fields. In the theoretical modeling of those cases, the common assumptions are often insufficient to determine the boundary detection parameters, such as receiving bandwidth or saturation point, critical for practical considerations of atomic sensing technology. This evokes the resurfacing of a long-standing problem on how to describe an atom-light interaction in a fractured loop. In such a case, the quantum steady state is not achieved even with constant, continuous interactions. Here we propose a method for modeling of such a system, basing our approach on the Fourier expansion of a non-equilibrium steady state. The proposed solution is both numerically effective and able to predict edge cases, such as saturation. Furthermore, as an example, we employ this method to provide a complete description of a Rydberg superheterodyne receiver, obtaining the boundary parameters describing the operation of this atomic detector.

physics.atom-ph↗

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

Continuous wideband microwave-to-optical converter based on room-temperature Rydberg atoms

The coupling of microwave and optical systems presents an immense challenge due to the natural incompatibility of energies, but potential applications range from optical interconnects for quantum computers to next-generation quantum microwave sensors, detectors or coherent imagers. Several engineered platforms have emerged that are constrained by specific conditions, such as cryogenic environments, impulse protocols, or narrowband fields. Here we employ Rydberg atoms that allow for the natural wideband coupling of optical and microwave photons even at room temperature and with the use of a modest setup. We present continuous-wave conversion of a $13.9\ \mathrm{GHz}$ field to a near-infrared optical signal using an ensemble of Rydberg atoms via a free-space six-wave mixing process, designed to minimize noise interference from any nearby frequencies. The Rydberg photonic converter exhibits an unprecedented conversion dynamic range of $57\ \mathrm{dB}$ and a wide conversion bandwidth of $16\ \mathrm{MHz}$. Using photon counting, we demonstrate the readout of photons of free-space $300\ \mathrm{K}$ thermal background radiation at $1.59\ \mathrm{nV}\mathrm{cm}^{-1}(\mathrm{rad}/\mathrm{s})^{-1/2}$ ($3.98 \ \mathrm{nV}\mathrm{cm}^{-1}\mathrm{Hz}^{-1/2}$) with the sensitivity down to $3.8\ \mathrm{K}$ of noise-equivalent temperature, allowing us to observe Hanbury Brown and Twiss interference of microwave photons.

quant-ph↗

arXiv2022

Sensitivity of Rydberg-atom receiver to frequency and amplitude modulation of microwaves

Electromagnetically induced transparency (EIT) in atomic systems involving Rydberg states is known to be a sensitive probe of incident microwave (MW) fields, in particular those resonant with Rydberg-to-Rydberg transitions. Here we propose an intelligible analytical model of Rydberg atomic receiver's response to amplitude- (AM) and frequency-modulated (FM) signals, and compare it with experimental results: we present a setup that allows sending signals with either AM or FM and evaluating their efficiency with demodulation. Additionally, the setup reveals a new detection configuration, using all circular polarizations for optical fields and allowing detection of circularly polarized MW field, propagating colinearly with optical beams. In our measurements we systematically present that several parameters exhibit local optimum characteristics and then estimate these optimal parameters and working ranges, addressing the need to devise a robust Rydberg MW sensor and its operational protocol.

physics.atom-ph↗

arXiv2018

Beating the Rayleigh Limit Using Two-Photon Interference

Multiparameter estimation theory offers a general framework to explore imaging techniques beyond the Rayleigh limit. While optimal measurements of single parameters characterizing a composite light source are now well understood, simultaneous determination of multiple parameters poses a much greater challenge that in general requires implementation of collective measurements. Here we show, theoretically and experimentally, that Hong-Ou-Mandel interference followed by spatially resolved detection of photons provides precise information on both the separation and the centroid for a pair of point emitters, avoiding trade-offs inherent to single-photon measurements.

quant-ph↗