60 citations · 305 across the 30 of their papers we have counts for
24 papers · 1 filter
A robust framework for the comprehensive characterisation of parametric down-conversion sources
Denis A. Kopylov, Michael Stefszky, Christine Silberhorn
Reliable verification of squeezed-light sources is essential for photonic quantum technologies. High-dimensional quantum optical networks demand single-mode, pure squeezed states w…
Pathway-resolved analysis of internal conversion enabled by Gaussian boson sampling
Mikhail Roiz, Rashid Valiev, Jan-Lucas Eickmann +4
Gaussian Boson Sampling (GBS) has provided strong evidence of quantum advantage, motivating the search for real-world applications. Such applications rely on mapping physical probl…
An ultra-bright, highly-scalable, squeezed light source for hybrid quantum photonics
Kai-Hong Luo, Denis Kopylov, Florian Lütkewitte +8
Hybrid quantum photonics seeks to combine the complementary advantages of continuous- and discrete-variable quantum optics. This typically entails photon-counting measurements on e…
Macroscopic photon counting beating the Poisson noise limit
Timon Schapeler, Fabian Schlue, Isabell Mischke +4
Photon counting is a cornerstone of quantum optics. Here, we demonstrate precisely counting from 0 to over 9000 photons, beating the Poisson noise limit by at least $4.1~\mathrm{dB…
Benchmarking Gaussian and non-Gaussian input states with a hybrid sampling platform
Michael Stefszky, Kai-Hong Luo, Jan-Lucas Eickmann +22
The original boson sampling paradigm-consisting of multiple single-photon input states, a large interferometer, and multi-channel click detection-was originally proposed as a photo…
Practical considerations for assignment of photon numbers with SNSPDs
Timon Schapeler, Isabell Mischke, Fabian Schlue +4
Superconducting nanowire single-photon detectors (SNSPDs) can enable photon-number resolution (PNR) based on accurate measurements of the detector's response time to few-photon opt…
Bridging chemistry and Gaussian boson sampling: A photonic hierarchy of approximations for molecular vibronic spectra
Jan-Lucas Eickmann, Kai-Hong Luo, Mikhail Roiz +10
Simulating vibronic spectra is a central task in physical chemistry, offering insight into important properties of molecules. Recently, it has been experimentally demonstrated that…
Optimizing photon-number resolution with superconducting nanowire multi-photon detectors
Timon Schapeler, Fabian Schlue, Michael Stefszky +3
In this paper we briefly review the state-of-the-art of intrinsic photon-number resolution (PNR) with superconducting nanowire single-photon detectors (SNSPDs) and will provide an…
Jitter in photon-number-resolved detection by superconducting nanowires
Mariia Sidorova, Timon Schapeler, Alexej D. Semenov +5
By analyzing the physics of multi-photon absorption in superconducting nanowire single-photon detectors (SNSPDs), we identify physical components of jitter. From this, we formulate…
Erasing Photon-Number Correlations through Hong-Ou-Mandel Interference
Fabian Schlue, Patrick Folge, Takefumi Nomura +6
A parametric down-conversion source interfering on a beam splitter can be described as both a source of entangled N00N-states or a source of independent, and thus uncorrelated sque…
Spectral and temporal properties of type-II parametric down-conversion: The impact of losses during state generation
Denis A. Kopylov, Michael Stefszky, Torsten Meier +2
In this paper, we theoretically study spectral and temporal properties of pulsed spontaneous parametric down-conversion (SPDC) generated in lossy waveguides. Our theoretical approa…
Ultra-broadband non-degenerate guided-wave bi-photon source in the near and mid-infrared
Franz Roeder, Abira Gnanavel, René Pollmann +6
The latest applications in ultrafast quantum metrology require bright, broadband bi-photon sources with one of the photons in the mid-infrared and the other in the visible to near…
A scheme for fully programmable linear quantum networks based on frequency conversion
Patrick Folge, Michael Stefszky, Benjamin Brecht +1
Linear optical quantum networks, consisting of a quantum input state and a multi-port interferometer, are an important building block for many quantum technological concepts, e.g.,…
How well can superconducting nanowire single-photon detectors resolve photon number?
Timon Schapeler, Niklas Lamberty, Thomas Hummel +5
We apply principal component analysis (PCA) to a set of electrical output signals from a commercially available superconducting nanowire single-photon detector (SNSPD) to investiga…
Measurement of ultrashort bi-photon correlation times with an integrated two-colour broadband SU(1,1)-interferometer
F. Roeder, R. Pollmann, M. Stefszky +7
The bi-photon correlation time, a measure for the conditional uncertainty in the temporal arrival of two photons from a photon pair source, is a key performance identifier for many…
Fully guided and phase locked Ti:PPLN waveguide squeezing for applications in quantum sensing
Renato Domeneguetti, Michael Stefszky, Harald Herrmann +4
This work reports a fully guided setup for single-mode squeezing generation on integrated titanium-indiffused periodically poled nonlinear resonators. A continuous wave laser beam…
Demonstration of Hong-Ou-Mandel interference in an LNOI directional coupler
Silia Babel, Laura Bollmers, Marcello Massaro +9
Interference between single photons is key for many quantum optics experiments and applications in quantum technologies, such as quantum communication or computation. It is advanta…
Lossy SU(1,1) interferometers in the single-photon-pair regime
Matteo Santandrea, Kai-Hong Luo, Michael Stefszky +3
The success of quantum technologies is intimately connected to the possibility of using them in real-world applications. To this aim, we study the sensing capabilities of quantum S…
Realization of a multi-output quantum pulse gate for decoding high-dimensional temporal modes of single-photon states
Laura Serino, Jano Gil-Lopez, Michael Stefszky +4
Temporal modes (TMs) of photons provide an appealing high-dimensional encoding basis for quantum information. While techniques to generate TM states have been established, high-dim…
Quantum optical coherence: From linear to nonlinear interferometers
K. -H. Luo, M. Santandrea, M. Stefszky +6
Interferometers provide a highly sensitive means to investigate and exploit the coherence properties of light in metrology applications. However, interferometers come in various fo…
Spectrally multimode integrated SU(1,1) interferometer
Alessandro Ferreri, Matteo Santandrea, Michael Stefszky +4
Nonlinear SU(1,1) interferometers are fruitful and promising tools for spectral engineering and precise measurements with phase sensitivity below the classical bound. Such interfer…
Fabrication limits of waveguides in nonlinear crystals and their impact on quantum optics applications
Matteo Santandrea, Michael Stefszky, Vahid Ansari +1
Waveguides in nonlinear materials are a key component for photon pair sources and offer promising solutions to interface quantum memories through frequency conversion. To bring the…
Second-harmonic enhanced feedforward intensity noise eater
Michael Stefszky, Christine Silberhorn
Quantum nondemolition theory has been well understood for a number of decades, however, applications of such techniques remain limited owing to the increased complexity that these…
Bright Integrated Photon-Pair Source for Practical Passive Decoy-State Quantum Key Distribution
Stephan Krapick, Michael Stefszky, Michal Jachura +3
We report on a bright, nondegenerate type-I parametric down-conversion source, which is well suited for passive decoy-state quantum key distribution. We show the photon-number-reso…