- 标题
- 摘要
- 关键词
- 实验方案
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Electromagnetically induced holographic imaging with Rydberg atoms
摘要： Electromagnetically induced holographic imaging using strongly interacting Rydberg atoms is investigated via electromagnetically induced grating (EIG). We consider two schemes, i.e., by direct detection of holographic imaging pattern, known as electromagnetically induced classical holographic imaging (EICHI), and by employing entangled photon pairs for imaging which is called as electromagnetically induced quantum holographic imaging (EIQHI). Both the schemes are employed to obtain 1D and 2D holographic imaging. In EICHI and EIQHI, amplitude and phase information of EIG can be imaged with controllable image variation in size. It is noticed that holographic imaging is influenced by van der Waals (vdW) effect present in Rydberg atoms.
关键词： Electromagnetically induced grating,Rydberg atoms,Quantum imaging,Electromagnetically induced holographic imaging,van der Waals effect
更新于2025-09-23 15:23:52
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Quantum reference beacon–guided superresolution optical focusing in complex media
摘要： Optical scattering is generally considered to be a nuisance of microscopy that limits imaging depth and spatial resolution. Wavefront shaping techniques enable optical imaging at unprecedented depth, but attaining superresolution within complex media remains a challenge. We used a quantum reference beacon (QRB), consisting of solid-state quantum emitters with spin-dependent fluorescence, to provide subwavelength guidestar feedback for wavefront shaping to achieve a superresolution optical focus. We implemented the QRB-guided imaging with nitrogen-vacancy centers in diamond nanocrystals, which enable optical focusing with a subdiffraction resolution below 186 nanometers (less than half the wavelength). QRB-assisted wavefront-shaping should find use in a range of applications, including deep-tissue quantum enhanced sensing and individual optical excitation of magnetically coupled spin ensembles for applications in quantum information processing.
关键词： complex media,nitrogen-vacancy centers,quantum imaging,superresolution,quantum reference beacon,optical focusing,wavefront shaping
更新于2025-09-19 17:15:36
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Quantum-Classical Image Distillation
摘要： Imaging with quantum states of light promises advantages over classical approaches in terms of resolution, signal-to-noise ratio and sensitivity. However, quantum images are sensitive to losses and other sources of classical noise (e.g. optical reflections, background illumination, …) that cancel any advantage in the final result. Here, we experimentally demonstrate a technique that allows selective distillation of a quantum image from a camera measurement composed of a superposition of both quantum and classical light. While photons illuminated by classical coherent light are uncorrelated, pairs of photons generated by spontaneous parametric down conversion (SPDC) are correlated in position. In the experiments, we superimpose on the camera two distinct images (a ‘dead’ and an ‘alive’ cat), one obtained by illuminating an intensity mask (of a ‘dead’ cat) with entangled photons and the other obtained by illuminating an intensity mask (of an ‘alive’ cat) with a classical LED source. Using the full dynamic range of an Electron Multiplied Charge Coupled Device (EMCCD) camera, in the high photon flux regime, we exploit the intensity correlations of the quantum source to extract the “quantum” image from the mixed quantum-classical image. We then also reconstruct the classical image by subtraction. Moreover, we investigate the impact of classical light on the signal-to-noise ratio and show that quantum image information can be retrieved even when the classical illumination is ten times higher than the quantum illumination.
关键词： classical noise,intensity correlations,SPDC,EMCCD camera,quantum imaging
更新于2025-09-16 10:30:52
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Spatial squeezing in bright twin beams generated with four-wave mixing: Constraints on characterization with an electron-multiplying charge-coupled-device camera
摘要： The observation of spatial quantum noise reduction, or spatial squeezing, with a large number of photons can lead to a significant advantage in quantum imaging and quantum metrology due to the scaling of the signal-to-noise ratio with the number of photons. Here we present a systematic study of the limiting factors that play a role on the measurement of spatial squeezing with an electron-multiplying charge-coupled device (EMCCD) camera in the limit of bright quantum states of light generated with a four-wave mixing process in an atomic vapor cell. We detect a total number of photons per beam of the order 108 in 1 μs pulses, which corresponds to a photon flux per beam of the order of 1014 photons per second. We then investigate the role of different parameters, such as cell temperature, pump power, laser detunings, scattered pump background noise, and timing sequences for the image acquisition with the EMCCD camera, on the level of spatial squeezing. We identify critical parameters to obtain an optimum squeezing level and demonstrate that for bright beams it is essential to acquire images at a rate fast enough to overcome the effect of classical technical noise.
关键词： spatial squeezing,atomic vapor cell,quantum imaging,spatial quantum noise reduction,quantum metrology,four-wave mixing,EMCCD camera
更新于2025-09-12 10:27:22
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Mid-Infrared Sensing by Induced Coherence in a Single Nonlinear Waveguide
摘要： Induced coherence (IC) between two spatially separated but indistinguishable spontaneous parametric down conversion (SPDC) processes underpins the recent revival of nonlinear interferometry and has led to new applications in quantum imaging and mid-infrared (MIR) spectroscopy [1,2]. These applications exploit induced coherence and the spectral or spatial correlations between signal and idler photons generated through SPDC. Here, we theoretically describe the phenomenon of IC in a general way by making use of a quantum-mechanical approach based on the classical Green’s function (GF) of the system [3,4]. Our formalism is well suited for treating generic linear optical properties of a system, including loss, and studying their influence on the IC phenomena. Moreover, our approach can account for arbitrary spatial profiles of the nonlinearity and hence can be used to describe generalized IC experiments with different number of photon-pair sources. Here we propose a sensing experiment using a single nonlinear waveguide [5] and investigate IC using our formalism. We find that in this case a substance under test inside or surrounding the waveguide can affect the IC during the generation stage along the nonlinear waveguide, making this a compact scheme for MIR spectroscopy without the need for MIR detectors.
关键词： spontaneous parametric down conversion,quantum imaging,nonlinear interferometry,mid-infrared spectroscopy,induced coherence
更新于2025-09-11 14:15:04
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Importance and Applications of Infinite Dimensional Non-Orthogonal Quantum State
摘要： This paper introduces remarkable achievement in theory on non-orthogonal state in quantum optics that can describe macroscopic quantum effect, and gives a survey of theorems in quantum information science based on non-orthogonal state. Then it is shown that these provide potential applications to Quantum Methodology such as quantum reading, quantum imaging and to Quantum Enigma Cipher which is a general model of physical cipher.
关键词： Quantum Enigma cipher,03.67.Dd,42.50.Lc,Quantum imaging,Entangled coherent state,Quantum reading,Quantum illumination
更新于2025-09-10 09:29:36
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Beating the Rayleigh Limit Using Two-Photon Interference
摘要： 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.
关键词： quantum imaging,Multiparameter estimation,superresolution,Hong-Ou-Mandel interference
更新于2025-09-04 15:30:14