Publications (225)
Huygens' Dipole for Polarization-Controlled Nanoscale Light Routing
Sergey Nechayev, Jörg S. Eismann, Martin Neugebauer +4
Structured illumination allows for satisfying the first Kerker condition of in-phase perpendicular electric and magnetic dipole moments in any isotropic scatterer that supports ele…
Tighter spots of light with superposed orbital angular momentum beams
PaweŠWoźniak, Peter Banzer, Frédéric Bouchard +3
The possibility of focusing light to an ever tighter spot has important implications for many applications and fields of optics research, such as nano-optics and plasmonics, laser-…
An algorithm for the optical equivalence theorem
Marco Ornigotti, Andrea Aiello, Gerd Leuchs
A coherent state representation of the expectation value of an arbitrary (but still polynomial) normal ordered quantum operator is discussed. This serves as a basis for developing…
Dielectric tuning and coupling of whispering gallery modes using an anisotropic prism
Matthew R. Foreman, Florian Sedlmeir, Harald G. L. Schwefel +1
Optical whispering gallery mode (WGM) resonators are a powerful and versatile tool used in many branches of science. Fine tuning of the central frequency and line width of individu…
Polarization-entangled photons from a whispering gallery resonator
Sheng-Hsuan Huang, Thomas Dirmeier, Golnoush Shafiee +4
Crystalline Whispering Gallery Mode Resonators (WGMRs) have been shown to facilitate versatile sources of quantum states that can efficiently interact with atomic systems. These fe…
Transverse Kerker Scattering for Angstrom Localization of Nanoparticles
Ankan Bag, Martin Neugebauer, PaweŠWoźniak +2
Angstrom precision localization of a single nanoantenna is a crucial step towards advanced nanometrology, medicine and biophysics. Here, we show that single nanoantenna displacemen…
Atmospheric continuous-variable quantum communication
Bettina Heim, Christian Peuntinger, Nathan Killoran +4
We present a quantum communication experiment conducted over a point-to-point free-space link of 1.6 km in urban conditions. We study atmospheric influences on the capability of th…
Experiment towards continuous-variable entanglement swapping: Highly correlated four-partite quantum state
Oliver Glöckl, Stefan Lorenz, Christoph Marquardt +7
We present a protocol for performing entanglement swapping with intense pulsed beams. In a first step, the generation of amplitude correlations between two systems that have never…
The many facets of the Fabry-Perot
Luis L. Sanchez-Soto, Juan J. Monzon, Gerd Leuchs
We address the response, both in amplitude and intensity, of a Fabry-Perot from a variety of viewpoints. These complementary pictures conspire to achieve a comprehensive and consis…
Nonlinear power dependence of the spectral properties of an optical parametric oscillator below threshold in the quantum regime
Golnoush Shafiee, Dmitry V. Strekalov, Alexander Otterpohl +6
Photon pairs and heralded single photons, obtained from cavity-assisted parametric down-conversion (PDC), play an important role in quantum communications and technology. This moti…
Benchmarking quantum phase-space methods for near-resonant light propagation
Mojdeh S. Najafabadi, Joel F. Corney, Luis Sanchez Soto +1
We study the dynamics of light interacting with a near-resonant atomic medium using the truncated Wigner and positive P phase-space representations. The atomic degrees of freedom a…
Efficient single photon absorption by a trapped moving atom
Nils Trautmann, Gernot Alber, Gerd Leuchs
The influence of the center of mass motion of a trapped two level system on efficient resonant single photon absorption is investigated. It is shown that this absorption process de…
Quantum polarization characterization and tomography
Jonas Soderholm, Gunnar Bjork, Andrei B. Klimov +2
We present a complete polarization characterization of any quantum state of two orthogonal polarization modes, and give a systematic measurement procedure to collect the necessary…
Benchmarking quantum tomography completeness and fidelity with machine learning
Yong Siah Teo, Seongwook Shin, Hyunseok Jeong +8
We train convolutional neural networks to predict whether or not a set of measurements is informationally complete to uniquely reconstruct any given quantum state with no prior inf…
Free-space quantum signatures using heterodyne detection
Callum Croal, Christian Peuntinger, Bettina Heim +6
Digital signatures guarantee the authorship of electronic communications. Currently used "classical" signature schemes rely on unproven computational assumptions for security, whil…
Comment on "Inherent security of phase coding quantum key distribution systems against detector blinding attacks" [Laser Phys. Lett. 15, 095203 (2018)]
Aleksey Fedorov, Ilja Gerhardt, Anqi Huang +8
This is a brief comment on the Letter by Balygin and his coworkers [Laser Phys. Lett. 15, 095203 (2018)]. We point out an error that invalidates the Letter's conclusions.
Transverse angular momentum of photons
Andrea Aiello, Christoph Marquardt, Gerd Leuchs
We develop the quantum theory of transverse angular momentum of light beams. The theory applies to paraxial and quasi-paraxial photon beams in vacuum, and reproduces the known resu…
Kerr-induced non-Gaussianity of ultrafast bright squeezed vacuum
Andrei Rasputnyi, Ilya Karuseichyk, Gerd Leuchs +2
Non-Gaussian states of light are a critical resource for fault-tolerant quantum computing and enhanced metrology, but are typically faint and often obtained via post-selection. Her…
Shaping a single photon without interacting with it
Denis Sych, Valentin Averchenko, Gerd Leuchs
Complete control over the properties of light up to the level of single photons is an invaluable tool for quantum information science and fundamental studies of light-matter intera…
Noise-Powered Probabilistic Concentration of Phase Information
Mario A. Usuga, Christian R. Mueller, Christoffer Wittmann +5
Phase insensitive optical amplification of an unknown quantum state is known to be a fundamentally noisy operation that inevitably adds noise to the amplified state [1 - 5]. Howeve…
Quantum Uncertainty in the Beam Width of Spatial Optical Modes
Vanessa Chille, Peter Banzer, Andrea Aiello +4
We theoretically investigate the quantum uncertainty in the beam width of transverse optical modes and, for this purpose, define a corresponding quantum operator. Single mode state…
Two-Photon Polarization Interference for Pulsed SPDC in a PPKTP Waveguide
Malte Avenhaus, Maria V. Chekhova, Leonid A. Krivitsky +2
We study the spectral properties of Spontaneous Parametric Down Conversion in a periodically poled waveguided structure of KTP crystal pumped by ultra-short pulses. Our theoretical…
Multiphoton Effects Enhanced Due to Ultrafast Photon-Number Fluctuations
Kirill Yu. Spasibko, Denis A. Kopylov, Victor L. Krutyanskiy +3
Multi-photon processes are the essence of nonlinear optics. Optical harmonics generation and multi-photon absorption, ionization, polymerization or spectroscopy are widely used in…
Heralded Source of Bright Multi-mode Mesoscopic Sub-Poissonian Light
Timur Sh. Iskhakov, Vladyslav C. Usenko, Ulrik L. Andersen +3
In a direct detection scheme we observed 7.8 dB of twin-beam squeezing for multi-mode two-color squeezed vacuum generated via parametric down conversion. Applying post-selection, w…
Entanglement of Gaussian states and the applicability to quantum key distribution over fading channels
Vladyslav C. Usenko, Bettina Heim, Christian Peuntinger +4
Entanglement properties of Gaussian states of light as well as the security of continuous variable quantum key distribution with Gaussian states in free-space fading channels are s…
Wave Phenomena and Wave Equations
Gerd Leuchs, Mojdeh S. Najafabadi
For any kind of wave phenomenon one can find ways to derive the respective dispersion relation from experimental observations and measurements. This dispersion relation determines…
Engineering the Frequency Spectrum of Bright Squeezed Vacuum via Group Velocity Dispersion in an SU(1,1) Interferometer
Samuel Lemieux, Mathieu Manceau, Polina R. Sharapova +4
Bright squeezed vacuum, a promising tool for quantum information, can be generated by high-gain parametric down-conversion. However, its frequency and angular spectra are typically…
Unveiling the optical properties of a metamaterial synthesized by electron-beam-induced deposition
PaweŠWoźniak, Katja Höflich, Gerald Brönstrup +3
The direct writing using a focused electron beam allows for fabricating truly three-dimensional structures of sub-wavelength dimensions in the visible spectral regime. The resultin…
Enhanced free space beam capture by improved optical tapers
Tim Bartley, Bettina Heim, Dominique Elser +6
In our continuous variable quantum key distribution (QKD) scheme, the homodyne detection set-up requires balancing the intensity of an incident beam between two photodiodes. Realis…
Conditionally generating a mesoscopic superposition of N00N states
Falk Töppel, Maria V. Chekhova, Gerd Leuchs
We study the generation of superpositions of N00N states by overlapping few-photon-subtracted squeezed vacuum states and coherent states on a 50/50 beam splitter. Assuming paramete…
Squeezed vacuum states from a whispering gallery mode resonator
Alexander Otterpohl, Florian Sedlmeir, Ulrich Vogl +9
Squeezed vacuum states enable optical measurements below the quantum limit and hence are a valuable resource for applications in quantum metrology and also quantum communication. H…
Atmospheric Channel Characteristics for Quantum Communication with Continuous Polarization Variables
Bettina Heim, Dominique Elser, Tim Bartley +5
We investigate the properties of an atmospheric channel for free space quantum communication with continuous polarization variables. In our prepare-and-measure setup, coherent pola…
Attacks on practical quantum key distribution systems (and how to prevent them)
Nitin Jain, Birgit Stiller, Imran Khan +3
With the emergence of an information society, the idea of protecting sensitive data is steadily gaining importance. Conventional encryption methods may not be sufficient to guarant…
Distribution of squeezed states through an atmospheric channel
Christian Peuntinger, Bettina Heim, Christian R. Müller +3
Continuous variable quantum states of light are used in quantum information protocols and quantum metrology and known to degrade with loss and added noise. We were able to show the…
The photonic wheel: demonstration of a state of light with purely transverse angular momentum
Peter Banzer, Martin Neugebauer, Andrea Aiello +4
The concept of angular momentum is ubiquitous to many areas of physics. In classical mechanics, a system may possess an angular momentum which can be either transverse (e.g., in a…
Focusing light with a deep parabolic mirror
Norbert Lindlein, Markus Sondermann, Robert Maiwald +3
The smallest possible focus is achieved when the focused wave front is the time reversed copy of the light wave packet emitted from a point in space (S. Quabis et al., Opt. Commun.…
Experimental Demonstration of Commutation Relations Using Intensity Correlations
Hans Dang, Sebastian Luff, Martin Fischer +4
The canonical commutation relation is a cornerstone of quantum theory and underlies the Heisenberg uncertainty principle. Although uncertainty relations have been extensively teste…
Experimental Demonstration of Macroscopic Quantum Coherence in Gaussian States
Christoph Marquardt, Ulrik L. Andersen, Gerd Leuchs +4
We witness experimentally the presence of macroscopic coherence in Gaussian quantum states using a recently proposed criterion (E.G. Cavalcanti and M. Reid, Phys. Rev. Lett. 97, 17…
Autonomous absolute calibration of an ICCD camera in single-photon detection regime
Luo Qi, Felix Just, Gerd Leuchs +1
Intensified charge coupled device (ICCD) cameras are widely used in various applications such as microscopy, astronomy, spectroscopy. Often they are used as single-photon detectors…
An operational distinction between quantum entanglement and classical non-separability
Natalia Korolkova, Luis Sánchez-Soto, Gerd Leuchs
Quantum entanglement describes superposition states in multi-dimensional systems, at least two partite, which cannot be factorized and are thus non-separable. Non-separable states…
Quantum uniqueness
Denis Sych, Gerd Leuchs
In the classical world one can construct two identical systems which have identical behavior and give identical measurement results. We show this to be impossible in the quantum do…
Scattering of an exponential pulse by a single atom
Markus Sondermann, Gerd Leuchs
We discuss the scattering of a light pulse by a single atom in free space using a purely semi-classical framework. The atom is treated as a linear elastic scatterer allowing to tre…
Efficient saturation of an ion in free space
Martin Fischer, Marianne Bader, Robert Maiwald +3
We report on the demonstration of a light-matter interface coupling light to a single ion in free space. The interface is realized through a parabolic mirror…
Nonlinear and Quantum Optics with Whispering Gallery Resonators Revisited
Dmitry V. Strekalov, Nicholas J. Lambert, Christoph Marquardt +5
In 2016 we published a review paper "Nonlinear and Quantum Optics with Whispering Gallery Resonators" (1). While writing this review, we found it often necessary to defer addressin…
Observation of robust polarization squeezing via the Kerr nonlinearity in an optical fibre
Nikolay Kalinin, Thomas Dirmeier, Arseny Sorokin +5
Squeezed light is one of the resources of photonic quantum technology. Among the various nonlinear interactions capable of generating squeezing, the optical Kerr effect is particul…
The duality principle in the presence of postselection
Jonathan Leach, Eliot Bolduc, Filippo. M. Miatto +3
The duality principle, a cornerstone of quantum mechanics, limits the coexistence of wave and particle behaviours of quantum systems. This limitation takes a quantitative form when…
Composable free-space continuous-variable quantum key distribution using discrete modulation
Kevin Jaksch, Thomas Dirmeier, Yannick Weiser +16
Continuous-variable (CV) quantum key distribution (QKD) allows for quantum secure communication with the benefit of being close to existing classical coherent communication. In rec…
Generation of a wave packet tailored to efficient free space excitation of a single atom
Andrea Golla, Benoit Chalopin, Marianne Bader +6
We demonstrate the generation of an optical dipole wave suitable for the process of efficiently coupling single quanta of light and matter in free space. We employ a parabolic mirr…
Detecting the spatial quantum uncertainty of bosonic systems
Vanessa Chille, Nicolas Treps, Claude Fabre +3
We present the quantum theory of the measurement of bosonic particles by multipixel detectors. For the sake of clarity, we specialize on beams of photons. We study the measurement…
Mie resonances in optical trapping: Their role in kinematics and back-action
Sharareh Sayyad, Gerd Leuchs, Vsevolod Salakhutdinov
The heating rate plays a crucial role in the decoherence of the harmonic motion of an optically levitated nanoparticle. The values of this rate vary depending on both the scatterin…
Geometric spin Hall effect of light in tightly focused polarization tailored light beams
Martin Neugebauer, Peter Banzer, Thomas Bauer +4
Recently, it was shown that a non-zero transverse angular momentum manifests itself in a polarization dependent intensity shift of the barycenter of a paraxial light beam [A. Aiell…
Unconditional quantum cloning of coherent states with linear optics
Ulrik L. Andersen, Vincent Josse, Gerd Leuchs
A scheme for optimal Gaussian cloning of optical coherent states is proposed and experimentally demonstrated. Its optical realization is based entirely on simple linear optical ele…
Coherent State Quantum Key Distribution with Multi Letter Phase-Shift Keying
Denis Sych, Gerd Leuchs
We present a protocol for quantum key distribution using discrete modulation of coherent states of light. Information is encoded in the variable phase of coherent states which can…
Macroscopic Hong-Ou-Mandel interference
Timur Sh. Iskhakov, Kirill Yu. Spasibko, Maria V. Chekhova +1
We report on a Hong-Ou-Mandel (HOM) interference experiment for quantum states with photon numbers per mode as large as 10^6 generated via high-gain parametric down conversion (PDC…
Near optimal discrimination of binary coherent signals via atom-light interaction
Rui Han, János A. Bergou, Gerd Leuchs
We study the discrimination of weak coherent states of light with significant overlaps by nondestructive measurements on the light states through measuring atomic states that are e…
Transverse Entanglement of Biphotons
Felix Just, Andrea Cavanna, Maria V. Chekhova +1
We measure the transverse entanglement of photon pairs on their propagation from the near to the far field of spontaneous parametric downconversion (SPDC). The Fedorov ratio, depen…
Chiroptical response of a single plasmonic nanohelix
PaweŠWoźniak, Israel De Leon, Katja Höflich +4
We investigate the chiroptical response of a single plasmonic nanohelix interacting with a weakly-focused circularly-polarized Gaussian beam. The optical scattering at the fundamen…
Near-infrared single-photon spectroscopy of a whispering gallery mode resonator using energy-resolving transition edge sensors
Michael Förtsch, Thomas Gerrits, Martin J. Stevens +9
We demonstrate a method to perform spectroscopy of near-infrared single photons without the need of dispersive elements. This method is based on a photon energy resolving transitio…
Towards an optical far-field measurement of higher-order multipole contributions to the scattering response of nanoparticles
Thomas Bauer, Sergej Orlov, Gerd Leuchs +1
We experimentally show an all-optical multipolar decomposition of the lowest-order Eigenmodes of a single gold nanoprism using azimuthally and radially polarized cylindrical vector…
Exotic Looped Trajectories of Photons in Three-Slit Interference
Omar S. Magana-Loaiza, Israel De Leon, Mohammad Mirhosseini +8
The validity of the superposition principle and of Born's rule are well-accepted tenants of quantum mechanics. Surprisingly, it has recently been predicted that the intensity patte…
Quantum limits to center-of-mass measurements
Timothy Vaughan, Peter Drummond, Gerd Leuchs
We discuss the issue of measuring the mean position (center-of-mass) of a group of bosonic or fermionic quantum particles, including particle number fluctuations. We introduce a st…
Orbital-to-Spin Angular Momentum Conversion Employing Local Helicity
Sergey Nechayev, Jörg S. Eismann, Gerd Leuchs +1
Spin-orbit interactions in optics traditionally describe an influence of the polarization degree of freedom of light on its spatial properties. The most prominent example is the ge…
Geometric Spin Hall Effect of Light at Polarizing Interfaces
Jan Korger, Andrea Aiello, Christian Gabriel +4
The geometric Spin Hall Effect of Light (geometric SHEL) amounts to a polarization-dependent positional shift when a light beam is observed from a reference frame tilted with respe…
Atomic mercury vapor inside a hollow-core photonic crystal fiber
Ulrich Vogl, Christian Peuntinger, Nicolas Y. Joly +3
We demonstrate high atomic mercury vapor pressure in a kagomé-style hollow-core photonic crystal fiber at room temperature. After a few days of exposure to mercury vapor the fiber…
Poincaré sphere representation for classical inseparable Bell-like states of the electromagnetic field
Annemarie Holleczek, Andrea Aiello, Christian Gabriel +2
Classical beams of light with non-uniform polarization patterns (e.g. radially and azimuthally polarized doughnut beams) may exhibit quantum-like features as, for instance, insepar…
Detection loss tolerant supersensitive phase measurement with an SU(1,1) interferometer
Mathieu Manceau, Gerd Leuchs, Farid Khalili +1
In an unseeded SU(1,1) interferometer composed of two cascaded degenerate parametric amplifiers, with direct detection at the output, we demonstrate a phase sensitivity overcoming…
Indefinite-mean Pareto photon distribution from amplified quantum noise
Mathieu Manceau, Kirill Yu. Spasibko, Gerd Leuchs +2
Extreme events appear in many physics phenomena, whenever the probability distribution has a ''heavy tail'', differing very much from the equilibrium one. Most unusual are the case…
Compensation-Free High-Capacity Free-Space Optical Communication Using Turbulence-Resilient Vector Beams
Ziyi Zhu, Molly Janasik, Alexander Fyffe +7
Free-space optical communication is a promising means to establish versatile, secure and high-bandwidth communication for many critical point-to-point applications. While the spati…
Heralded temporal shaping of single photons enabled by entanglement
Valentin Averchenko, Denis Sych, Gerd Leuchs
We propose a method to produce pure single photons with an arbitrary designed temporal shape in a heralded, lossless and scalable way. As the indispensable resource, the method use…
Polarization-Entangled Light Pulses of 10^5 Photons
Timur Sh. Iskhakov, Ivan N. Agafonov, Maria V. Chekhova +1
We experimentally demonstrate polarization entanglement for squeezed vacuum pulses containing more than 10^5 photons. We also study photon-number entanglement by calculating the Sc…
Risk analysis of Trojan-horse attacks on practical quantum key distribution systems
Nitin Jain, Birgit Stiller, Imran Khan +3
An eavesdropper Eve may probe a quantum key distribution (QKD) system by sending a bright pulse from the quantum channel into the system and analyzing the back-reflected pulses. Su…
Focusing characteristics of a 4 parabolic mirror light-matter interface
Lucas Alber, Martin Fischer, Marianne Bader +3
Focusing with a 4 parabolic mirror allows for concentrating light from nearly the complete solid angle, whereas focusing with a single microscope objective limits the angle con…
Experimental generation of amplitude squeezed vector beams
Vanessa Chille, Stefan Berg-Johansen, Marion Semmler +4
We present an experimental method for the generation of amplitude squeezed high-order vector beams. The light is modified twice by a spatial light modulator such that the vector be…
Experimental Demonstration of Continuous Variable Cloning with Phase-Conjugate Inputs
Metin Sabuncu, Ulrik L. Andersen, Gerd Leuchs
We report the experimental demonstration of continuous variable cloning of phase conjugate coherent states as proposed by Cerf and Iblisdir (Phys. Rev. Lett. 87, 247903 (2001)). In…
Efficient generation of temporally shaped photons using nonlocal spectral filtering
Valentin Averchenko, Denis Sych, Christoph Marquardt +1
We study the generation of single-photon pulses with the tailored temporal shape via nonlocal spectral filtering. A shaped photon is heralded from a time-energy entangled photon pa…
The focus of light - linear polarization breaks the rotational symmetry of the focal spot
Ralf Dorn, Susanne Quabis, Gerd Leuchs
We experimentally demonstrate for the first time that a linearly polarized beam is focussed to an asymmetric spot when using a high-numerical aperture focussing system. This asymme…
Efficient coupling to an optical resonator by exploiting time-reversal symmetry
Marianne Bader, Simon Heugel, Alexander L. Chekhov +2
The interaction of a cavity with an external field is symmetric under time reversal. Thus, coupling to a resonator is most efficient when the incident light is the time reversed ve…
Photon-Atom Coupling with Parabolic Mirrors
Markus Sondermann, Gerd Leuchs
Efficient coupling of light to single atomic systems has gained considerable attention over the past decades. This development is driven by the continuous growth of quantum technol…
Polarization squeezing and continuous-variable polarization entanglement
Natalia Korolkova, Gerd Leuchs, Rodney Loudon +2
The Stokes-parameter operators and the associated Poincare sphere, which describe the quantum-optical polarization properties of light, are defined and their basic properties are r…
Highly efficient generation of single-mode photon pairs using a crystalline whispering gallery mode resonator
Michael Förtsch, Gerhard Schunk, Josef U. Fürst +8
We report a highly efficient source of narrow-band photon pairs based on parametric down-conversion in a crystalline whispering gallery mode resonator. Remarkably, each photon of a…
Residual and Destroyed Accessible Information after Measurements
Rui Han, Gerd Leuchs, Markus Grassl
When quantum states are used to send classical information, the receiver performs a measurement on the signal states. The amount of information extracted is often not optimal due t…
Continuous variable quantum key distribution using polarization encoding and post selection
Stefan Lorenz, Natalia Korolkova, Gerd Leuchs
We present an experimental demonstration of a quantum key distribution protocol using coherent polarization states. Post selection is used to ensure a low error rate and security a…
Removal of guided acoustic wave Brillouin scattering to the quantum-noise limit using symmetric interferometry in twisted photonic crystal fibers
Vishal Choudhury, Kevin Jaksch, Markus Lippl +3
Guided acoustic wave Brillouin scattering (GAWBS) is a major obstacle in fiber-based quantum and high-speed classical communication systems as well as in interferometry. The transv…
Nonlinear optics with full three-dimensional illumination
Rojiar Penjweini, Markus Weber, Markus Sondermann +2
We investigate the nonlinear optical process of third-harmonic generation in the thus far unexplored regime of focusing the pump light from a full solid angle, where the nonlinear…
Feedback Cooling and Thermometry of a Single Trapped Ion Using a Knife Edge
Hans Dang, Sebastian Luff, Martin Fischer +2
We report on a simple and easy to implement method of feedback cooling trapped ions to temperatures below those achievable using only Doppler cooling. Additionally, the feedback co…
Polarization Controlled Directional Scattering for Nanoscopic Position Sensing
Martin Neugebauer, PaweŠWoźniak, Ankan Bag +2
Controlling the propagation and coupling of light to sub-wavelength antennas is a crucial prerequisite for many nanoscale optical devices. Recently, the main focus of attention has…
Full-field mode sorter using two optimized phase transformations for high-dimensional quantum cryptography
Robert Fickler, Frédéric Bouchard, Enno Giese +3
High-dimensional encoding schemes have emerged as a novel way to perform quantum information tasks. For high dimensionality, temporal and transverse spatial modes of photons are th…
The Helstrom measurement: A nondestructive implementation
Rui Han, Gerd Leuchs, János A. Bergou
We discuss a novel implementation of the minimum error state discrimination measurement, originally introduced by Helstrom. In this implementation, instead of performing the optima…
Tools for detecting entanglement between different degrees of freedom in quadrature squeezed cylindrically polarized modes
Christian Gabriel, Andrea Aiello, Stefan Berg-Johansen +2
Quadrature squeezed cylindrically polarized modes contain entanglement not only in the polarization and spatial electric field variables but also between these two degrees of freed…
Raman-induced limits to efficient squeezing in optical fibers
Ruifang Dong, Joel Heersink, Joel F. Corney +3
We report new experiments on polarization squeezing using ultrashort photonic pulses in a single pass of a birefringent fiber. We measure what is to our knowledge a record squeezin…
Electronic noise-free measurements of squeezed light
Leonid A. Krivitsky, Ulrik L. Andersen, Ruifang Dong +3
We study the implementation of a correlation measurement technique for the characterization of squeezed light. We show that the sign of the covariance coefficient revealed from the…
Quantumness of Gaussian Discord: Experimental Evidence and Role of System-Environment Correlations
Vanessa Chille, Niall Quinn, Christian Peuntinger +5
We provide experimental evidence of quantum features in bi-partite states classified as entirely classical according to a conventional criterion based on the Glauber P-function but…
Time-Reversal-Symmetric Single-Photon Wave Packets for Free-Space Quantum Communication
Nils Trautmann, Gernot Alber, Girish S. Agarwal +1
Readout and retrieval processes are proposed for efficient, high-fidelity quantum state transfer between a matter qubit, encoded in the level structure of a single atom or ion, and…
Quantum-limited measurements of intensity noise levels in Yb-doped fiber amplifiers
Alexandra Popp, Victor Distler, Kevin Jaksch +7
We investigate the frequency-resolved intensity noise spectrum of an Yb-doped fiber amplifier down to the fundamental limit of quantum noise. We focus on the kHz and low MHz freque…
A "fair sampling" perspective on an apparent violation of duality
Eliot Bolduc, Jonathan Leach, Filippo M. Miatto +2
In the event in which a quantum mechanical particle can pass from an initial state to a final state along two possible paths, the duality principle states that "the simultaneous ob…
Quantum-limited measurements of optical signals from a geostationary satellite
Kevin Günthner, Imran Khan, Dominique Elser +13
The measurement of quantum signals that traveled through long distances is of fundamental and technological interest. We present quantum-limited coherent measurements of optical si…
Correlation Measurement of Squeezed Light
Leonid A. Krivitsky, Ulrik L. Andersen, Ruifang Dong +3
We study the implementation of a correlation measurement technique for the characterization of squeezed light which is nearly free of electronic noise. With two different sources o…
All-fibre source of amplitude-squeezed light pulses
Markus Meissner, Christoph Marquardt, Joel Heersink +4
An all-fibre source of amplitude squeezed solitons utilizing the self-phase modulation in an asymmetric Sagnac interferometer is experimentally demonstrated. The asymmetry of the i…
Nonlinear interactions and non-classical light
Dmitry V. Strekalov, Gerd Leuchs
Non-classical concerns light whose properties cannot be explained by classical electrodynamics and which requires invoking quantum principles to be understood. Its existence is a d…
Probabilistic Cloning of Coherent States without a Phase Reference
Christian R. Müller, Christoffer Wittmann, Petr Marek +4
We present a probabilistic cloning scheme operating independently of any phase reference. The scheme is based solely on a phase-randomized displacement and photon counting, omittin…