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oe1(光电查) - 科学论文

55 条数据
?? 中文(中国)
  • First experience with Belle II Aerogel RICH detector

    摘要: The Aerogel Ring-Imaging Cherenkov (ARICH) detector provides particle identification information in the forward endcap part of Belle II. It efficiently separates charged kaons from pions for momenta between 0.5 GeV/c and 4.0 GeV/c. Optical photons are emitted in a double layer aerogel radiator and detected by Hybrid Avalanche PhotoDetectors. ARICH was installed in Belle II at the end of 2017, the first phase of a complex detector calibration of electronic signals and preparation for physics signals calibration has been successfully concluded. Cherenkov rings, created by cosmic rays as well as by charged particles from beam collisions, have been observed. The kaon identification efficiency using D±? decays has been studied and its calibration is expected by the end of the commissioning phase when sufficient data is available.

    关键词: Cherenkov detectors,Calibration,Particle identification,Optical photons,Beam collisions

    更新于2025-09-23 15:21:01

  • Storage of RF photons in minimal conditions

    摘要: We investigate the minimal conditions to store coherently a RF pulse in a material medium. We choose a commercial quartz as a memory support because it is a widely available component with a high Q-factor. Pulse storage is obtained by varying dynamically the light–matter coupling with an analog switch. This parametric driving of the quartz dynamics can be alternatively interpreted as a stopped-light experiment. We obtain an ef?ciency of 26%, a storage time of 209 μs and a time-to-bandwidth product of 98 by optimizing the pulse temporal shape. The coherent character of the storage is demonstrated. Our goal is to connect different types of memories in the RF and optical domain for quantum information processing. Our motivation is essentially fundamental.

    关键词: quantum memory,quartz resonator,radiofrequency photons

    更新于2025-09-23 15:21:01

  • New approach to raising the resolution of position sensitive detector with moving current-voltage characteristic

    摘要: Position sensitive detectors (PSD) are widely applied for determining the coordinate of an optical signal and continuously tracking it. Currently, studies concerned with the possibility of further raising the spatial resolution of PSDs remain topical. In this paper, we present the results obtained in reaching an ultrahigh resolution for a device based on the PSD Multiscan with an integral operation principle which fundamentally differs from that of the lateral PSD. The PSD Multiscan design is based on an array of back-to-back photodiodes. Its optical signal coordinate read-out is formed via the moving current-voltage characteristic of the sensor directly on the PSD as an output potential proportional to the coordinate of the optical spot median. This measurement principle provides a continuous comparison of near-equal photocurrents, which maintains a high signal-to-noise ratio over the whole sensing area. The absence of computational operations in electronic circuits of the PSD Multiscan makes it possible to introduce a nonlinear amplifier element, which substantially improves the resolution of the device based on the sensor developed in the study (as good as 0.05 μm). It has been shown that the resolution remains high for detectors with different lengths and is independent of the position of the optical spot on the sensing area.

    关键词: Analogue electronic circuits,Photon detectors for UV, visible and IR photons (solid-state) (PIN diodes, APDs, Si-PMTs, G-APDs, CCDs, EBCCDs, EMCCDs etc),Optical detector readout concepts

    更新于2025-09-23 15:21:01

  • Virtual Photons: From the Lamb Shift to Black Holes

    摘要: While virtual processes are a well-known feature of quantum electrodynamics, the role of virtual photons—in phenomena ranging from the microscopic to the cosmic—is less generally appreciated.

    关键词: virtual photons,Unruh radiation,black holes,Lamb shift,quantum electrodynamics,Hawking radiation

    更新于2025-09-23 15:21:01

  • Formation of Nonclassical Optical States in Spaser Systems Controlled by an External Magnetic Field

    摘要: The quantum statistical and correlation properties of photons generated in a multiparticle spaser are investigated. A model of an effective subwavelength source of entangled photons controlled by an external magnetic field is proposed.

    关键词: external magnetic field,entangled photons,spaser systems,nonclassical optical states

    更新于2025-09-23 15:19:57

  • Probing exciton/exciton interactions with entangled photons: Theory

    摘要: Quantum entangled photons provide a sensitive probe of many-body interactions and offer a unique experimental portal for quantifying many-body correlations in a material system. In this paper, we present a theoretical demonstration of how photon–photon entanglement can be generated via interactions between coupled qubits. Here, we develop a model for the scattering of an entangled pair of photons from a molecular dimer. We develop a diagrammatic theory for the scattering matrix and show that one can correlate the von Neumann entropy of the outgoing bi-photon wave function with exciton exchange and repulsion interactions. We conclude by discussing possible experimental scenarios for realizing these ideas.

    关键词: exciton exchange,repulsion interactions,quantum entangled photons,von Neumann entropy,many-body interactions

    更新于2025-09-23 15:19:57

  • Spin-photon module for scalable network architecture in quantum dots

    摘要: Reliable information transmission between spatially separated nodes is fundamental to a network architecture for scalable quantum technology. Spin qubit in semiconductor quantum dots is a promising candidate for quantum information processing. However, there remains a challenge to design a practical path from the existing experiments to scalable quantum processor. Here we propose a module consisting of spin singlet-triplet qubits and single microwave photons. We show a high degree of control over interactions between the spin qubit and the quantum light field can be achieved. Furthermore, we propose preparation of a shaped single photons with an efficiency of 98%, and deterministic quantum state transfer and entanglement generation between remote nodes with a high fidelity of 90%. This spin-photon module has met the threshold of particular designed error-correction protocols, thus provides a feasible approach towards scalable quantum network architecture.

    关键词: quantum dots,spin qubits,quantum network,microwave photons,quantum state transfer

    更新于2025-09-23 15:19:57

  • Fast and efficient detection of 511 keV photons using Cherenkov light in PbF <sub/>2</sub> crystal, coupled to a MCP-PMT and SAMPIC digitization module

    摘要: We study the possibility to use the Cherenkov light for the e?cient detection of 511 keV photons with the goal to use it in TOF-PET. We designed and tested two detection modules consisting of PbF2 crystals attached to Planacon MCP-PMT XP85012. Ampli?ed PMT signals are digitized by the SAMPIC module with high readout rate, up to 105 events/s, and a negligible contribution to the time resolution, below 20 ps (FWHM). We developed a fast 2D scanning system to calibrate the PMT time response and studied in details the timing characteristics of the Planacon PMT. Using a radioactive 22Na source we measured a detection e?ciency of 24% for 511 keV photons in a 10 mm thick crystal and a coincidence resolving time of 280 ps. We analyzed the main factors limiting the time resolution of the large-surface detection module and proposed solutions to improve it, which will be tested in our future project.

    关键词: Photon detectors for UV, visible and IR photons (vacuum) (photomultipliers, HPDs, others),Cherenkov and transition radiation,Gamma camera, SPECT, PET PET/CT, coronary CT angiography (CTA)

    更新于2025-09-23 15:19:57

  • Reconstruction of X-rays spectra of clinical linear accelerators from transmission data with generalized simulated annealing

    摘要: The spectral distribution of megavoltage X-rays used in radiotherapy departments is a fundamental quantity from which, in principle, all relevant information required for radiotherapy treatments can be determined. The direct measurement is di?cult to achieve clinically and analyzing the transmission is a clinically viable indirect method for determining clinical linear accelerators photon spectra. In this method, transmission signals are acquired after the beam passes through di?erent thicknesses of attenuators. The objective of this work was the establishment and application of an indirect method that used a spectral model based on generalized simulated annealing algorithm to determine the spectrum of clinical linear accelerators photons based on the transmission curve. Analysis of the spectra was made by analytical determination of dosimetric quantities and related parameters.

    关键词: Spectrometry,Photons,Radiotherapy,Monte Carlo,Generalized simulated annealing

    更新于2025-09-23 15:19:57

  • Ghost Spectroscopy with Classical Correlated Amplified Spontaneous Emission Photons Emitted by An Erbium-Doped Fiber Amplifier

    摘要: We demonstrate wavelength-wavelength correlations of classical broad-band amplified spontaneous emission (ASE) photons emitted by an erbium-doped fiber amplifier (EDFA) in a wavelength regime around 1530 nm. We then apply these classical correlated photons in the framework of a real-world ghost spectroscopy experiment at a wavelength of 1533 nm to acetylene (C2H2) reproducing the characteristic absorption features of the C-H stretch and rotational bands. This proof-of-principle experiment confirms the generalization of an ASE source concept offering an attractive light source for classical ghost spectroscopy. It is expected that this will enable further disseminating ghost modality schemes by exploiting classical correlated photons towards applications in chemistry, physics and engineering.

    关键词: spectral correlations,quantum optics,coherence,correlated photons,erbium-doped fiber amplifier,photon correlation modalities,ghost imaging,amplified spontaneous emission (ASE),spectroscopy,ghost spectroscopy,ghost modalities

    更新于2025-09-19 17:15:36