arXiv subjects

Marcin Jastrzębski

Publications and source records attributed to Marcin Jastrzębski.

5 recordsLinked to original sources

arXiv2026

Coherent terahertz field tomographic imaging in warm Rydberg vapors

Rydberg atom-based sensors have emerged as highly sensitive tools for terahertz (THz) metrology, yet most current imaging techniques discard crucial phase information. In this Letter, we present a coherent THz-to-optical conversion scheme in warm Rb vapor that enables complex-amplitude field imaging. By manipulating the phase-matching conditions via an adjustable interference pattern of optical probe beams, we demonstrate the ability to perform tomographic reconstruction of the THz field distribution. We experimentally validate the spatial resolution and phase-sensitivity of the system by resolving sub-centimeter features and identifying incident angles of arrival. Our results establish a robust framework for phase-resolved THz imaging and holography using atomic vapors at room temperature.

physics.atom-ph↗

arXiv2025

A warm Rydberg atom-based quadrature amplitude-modulated receiver

Rydberg atoms exhibit remarkable sensitivity to electromagnetic fields, making them promising candidates for revolutionizing field sensors. Unlike conventional antennas, they neither disturb the measured field nor necessitate intricate calibration procedures. In this study, we propose a protocol for signal reception near the 2.4 GHz Wi-Fi frequency band, harnessing the capabilities of warm Rydberg atoms. Our focus lies on exploring various quadrature amplitude modulations and transmission frequencies through heterodyne detection. We offer a comprehensive characterization of our setup, encompassing the atomic response frequency range and attainable electric field amplitudes. Additionally, we delve into analyzing communication errors using Voronoi diagrams, along with evaluating the communication channel capacity across different modulation schemes. Our findings not only lay the groundwork for future wireless communication applications, but also present opportunities to refine protocols in classical communication and field sensing domains.

physics.atom-ph↗

arXiv2024

Variable electro-optic shearing interferometry for ultrafast single-photon-level pulse characterization

Despite the multitude of available methods, the characterisation of ultrafast pulses remains a challenging endeavour, especially at the single-photon level. We introduce a pulse characterisation scheme that maps the magnitude of its short-time Fourier transform. Contrary to many well-known solutions it does not require nonlinear effects and is therefore suitable for single-photon-level measurements. Our method is based on introducing a series of controlled time and frequency shifts, where the latter is performed via an electro-optic modulator allowing a fully-electronic experimental control. We characterized the full spectral and temporal width of a classical and single-photon-level pulse and successfully reconstructed their spectral phase and amplitude. The method can be extended by implementing a phase-sensitive measurement and is naturally well-suited to partially-incoherent light.

physics.optics↗

arXiv2024

Spectrum-to-position mapping via programmable spatial dispersion implemented in an optical quantum memory

Spectro-temporal processing is essential in reaching ultimate per-photon information capacity in optical communication and metrology. In contrast to the spatial domain, complex multimode processing in the time-frequency domain is however challenging. Here we propose a protocol for spectrum-to-position conversion using spatial spin wave modulation technique in gradient echo quantum memory. This way we link the two domains and allow the processing to be performed purely on the spatial modes using conventional optics. We present the characterization of our interface as well as the frequency estimation uncertainty discussion including the comparison with Cramér-Rao bound. The experimental results are backed up by numerical numerical simulations. The measurements were performed on a single-photon level demonstrating low added noise and proving applicability in a photon-starved regime. Our results hold prospects for ultra-precise spectroscopy and present an opportunity to enhance many protocols in quantum and classical communication, sensing, and computing.

quant-ph↗

arXiv2024

Experimental implementation of the optical fractional Fourier transform in the time-frequency domain

The fractional Fourier transform (FrFT), a fundamental operation in physics that corresponds to a rotation of phase space by any angle, is also an indispensable tool employed in digital signal processing for noise reduction. Processing of optical signals in their time-frequency degree of freedom bypasses the digitization step and presents an opportunity to enhance many protocols in quantum and classical communication, sensing and computing. In this letter, we present the experimental realization of the fractional Fourier transform in the time-frequency domain using an atomic quantum-optical memory system with processing capabilities. Our scheme performs the operation by imposing programmable interleaved spectral and temporal phases. We have verified the FrFT by analyses of chroncyclic Wigner functions measured via a shot-noise limited homodyne detector. Our results hold prospects for achieving temporal-mode sorting, processing and super-resolved parameter estimation.

quant-ph↗