Journal articles: '3 photon'

1

FA, OU, HE MINGGAO, and WU FUGEN. "OPTICAL NONLINEARITY VIA PHONONS AS AN INTERMEDIARY." Journal of Nonlinear Optical Physics & Materials 10, no. 01 (March 2001): 65–77. http://dx.doi.org/10.1142/s0218863501000449.

Full text

Abstract:

A new model to describe the origin of optical nonlinearity is presented. In this model, the interaction between light and medium is reduced to the coupling of photons with phonons, which occurs in the crystal lattice vibrating anharmonically. Then the optical nonlinearity originates from the nonlinear photon–phonon coupling or the interaction among phonons themselves. In this paper, more attention is drawn to the latter. By the given model, (1) degenerate and (2) nondegenerate parametric oscillations, (3) Stokes and (4) anti-Stokes Raman scattering, (5) sum-frequency and (6) second harmonic generation and (7) two-photon absorption are dealt with systematically and quantum-mechanically. The results of theoretical analysis show that the effects (1)–(4) are associated with threshold phenomenon, whereas the effects (5)–(7) with the saturation phenomenon.

APA, Harvard, Vancouver, ISO, and other styles

2

Tavares-Velasco, G., and J. J. Toscano. "Photon-photon scattering in a 3-3-1 model." Europhysics Letters (EPL) 53, no. 4 (February 2001): 465–70. http://dx.doi.org/10.1209/epl/i2001-00175-8.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

Chef, Samuel, Chung Tah Chua, and Chee Lip Gan. "Machine Learning for Time-Resolved Emission: Image Resolution Enhancement." EDFA Technical Articles 23, no. 3 (August 1, 2021): 24–31. http://dx.doi.org/10.31399/asm.edfa.2021-3.p024.

Full text

Abstract:

Abstract This article describes a novel method for improving image resolution achieved using time-resolved photon emission techniques. Instead of directly generating images from photon counting, all detected photons are displayed as a point cloud in 3D space and a new higher-resolution image is generated based on probability density functions associated with photon distributions. Unsupervised learning algorithms identify photon distribution patterns as well as fainter emission sources.

APA, Harvard, Vancouver, ISO, and other styles

4

U'Ren, A. B., K. Banaszek, and I. A. Walmsley. "Photon engineering for quantum information processing." Quantum Information and Computation 3, special (October 2003): 480–502. http://dx.doi.org/10.26421/qic3.s-3.

Full text

Abstract:

We study distinguishing information in the context of quantum interference involving more than one parametric downconversion (PDC) source and in the context of generating polarization-entangled photon pairs based on PDC. We arrive at specific design criteria for two-photon sources so that when used as part of complex optical systems, such as photon-based quantum information processing schemes, distinguishing information between the photons is eliminated guaranteeing high visibility interference. We propose practical techniques which lead to suitably engineered two-photon states that can be realistically implemented with available technology. Finally, we study an implementation of the nonlinear-sign shift (NS) logic gate with PDC sources and show the effect of distinguishing information on the performance of the gate.

APA, Harvard, Vancouver, ISO, and other styles

5

Hu, Huiqin, Xinyi Ren, Zhaoyang Wen, Xingtong Li, Yan Liang, Ming Yan, and E. Wu. "Single-Pixel Photon-Counting Imaging Based on Dual-Comb Interferometry." Nanomaterials 11, no. 6 (May 24, 2021): 1379. http://dx.doi.org/10.3390/nano11061379.

Full text

Abstract:

We propose and experimentally demonstrate single-pixel photon counting imaging based on dual-comb interferometry at 1550 nm. Different from traditional dual-comb imaging, this approach enables imaging at the photon-counting regime by using single-photon detectors combined with a time-correlated single-photon counter to record the returning photons. The illumination power is as low as 14 pW, corresponding to 2.2 × 10−3 photons/pulse. The lateral resolution is about 50 μm. This technique paves the way for applying dual-comb in remote sensing and imaging.

APA, Harvard, Vancouver, ISO, and other styles

6

White, John, Victoria Centonze, David Wokosin, and William Mohler. "Using Multiphoton Microscopy for the Study of Embryogenesis." Microscopy and Microanalysis 3, S2 (August 1997): 307–8. http://dx.doi.org/10.1017/s1431927600008424.

Full text

Abstract:

Multiphoton fluorescence excitation imaging is an optical sectioning technique for fluorescence microscopy. At very high photon densities, two or more photons may coordinately excite an energy transition in a fluorophore that corresponds to the sum of the energies of the individual photons. by this means, a fluorophore may be excited by a wavelength that is considerably longer than its single photon excitation wavelength. Ultra-fast pulsed (femtosecond) lasers can produce the peak power densities in the focal volume of an objective lens needed to provide sufficient 2- or 3- photon excitation events for imaging. The use of short-pulse lasers provides the high peak powers necessary for imaging yet with modest mean power levels that do not thermally damage biological specimens. Production of multiphoton events depends on the square of photon density for 2-photon excitation and the cube of photon density for 3-photon excitation. The power density therefore rapidly falls off away from the focal volume of an objective lens, thereby confining fluorescence excitation to the focal volume.

APA, Harvard, Vancouver, ISO, and other styles

7

Xiu, Xiao-Ming, Li Dong, Hong-Zhi Shen, Ya-Jun Gao, and X. X. Yi. "Two-party QPC with polarization-entangled Bell states and the coherent states." Quantum Information and Computation 14, no. 3&4 (March 2014): 236–54. http://dx.doi.org/10.26421/qic14.3-4-3.

Full text

Abstract:

We propose a protocol of quantum privacy comparison with polarization-entangled Einstein-Podolsky-Rosen (Bell) states and the coherent states. One of two legitimate participants, Alice, prepares polarization-entangled Bell states and keeps one photon of each photon pair and sends the other photons to the third party, Charlie. Receiving the photons, Charlie performs single-photon transformation operations on them and then sends them to the other legitimate participant, Bob. Three participants adopt parity analysis method to check the distribution security of Bell states. Exploiting polarization beam splitters and nonlinear interactions mediated by the probe coherent states in Kerr media, Alice and Bob check the parities of their photons using the bases of $\{\ket H, \ket V\}$ or $\{\ket +, \ket -\}$. On the basis of the parity analysis outcomes and Charlie's publicized information, they can analyze the security of the distributed quantum channel. Confirming secure distribution of the shared Bell states, two participants perform respective parity measurements on the privacy photons and own photons of Bell states, and then send the results to Charlie. According to information provided by two legitimate participants and his single-qubit transformation operations, Charlie compares the privacy information of Alice and Bob and publicizes the conclusion.

APA, Harvard, Vancouver, ISO, and other styles

8

Dhobi, Saddam Husain, Kishori Yadav, and Bhishma Karki. "Variation of Energy Density and Mass Density of Photon with Wavelength." Indian Journal of Advanced Physics 1, no. 2 (October 10, 2021): 1–5. http://dx.doi.org/10.54105/ijap.b1003.101221.

Full text

Abstract:

The mass density and energy density of visible photon is calculated as 10-8 Kgm-3 and 109jm3 respectively. Moreover it is also observed that mass density and energy density of photon depend upon photons mass, wavelength, volume and energy. This is clear from figure 1, figure 2 and literatures. Therefore the mass density and energy density of photon varies with masses of photon, wavelength, volume, etc.

APA, Harvard, Vancouver, ISO, and other styles

9

Chandra, N., and R. Ghosh. "Generation of entanglement between spin of an electron and polarization of a photon." Quantum Information and Computation 9, no. 1&2 (January 2009): 36–61. http://dx.doi.org/10.26421/qic9.1-2-3.

Full text

Abstract:

This paper shows an electron and a photon, emitted in two consecutive steps from an atom following the absorption of a single photon, may be entangled in the presence of the spin-orbit interaction only. This entanglement strongly depends upon the polarization of the absorbed and of the radiated photons, kinematics of two emitted particles, and dynamics of photoionization; however, the photoemission dynamics plays no role in this entanglement. This hybrid entanglement can be used in teleporting a quantum state encoded in a flying/stationary material particle onto a light pulse, or vice versa. Such an electron-photon entanglement, in addition, will make it possible to learn about the polarization of a single photon or spin-polarization of a free electron without making any measurements on the corresponding particle itself.

APA, Harvard, Vancouver, ISO, and other styles

10

Peresunko, D. "Direct photon production in pp, p–Pb and Pb–Pb collisions measured with the ALICE experiment." EPJ Web of Conferences 191 (2018): 05001. http://dx.doi.org/10.1051/epjconf/201819105001.

Full text

Abstract:

We review recent ALICE results on direct photon production in pp, p–Pb and Pb–Pb collisions at LHC energies. In light systems, pp and p–Pb, no signal of direct photons at low pT < 3-5 GeV/c is observed within uncertainties, while at high pT our measurements are consistent with NLO pQCD calculations. In central and mid-central Pb–Pb collisions a thermal photon contribution is observed at low pT < 3 - 4 GeV/c with slopes Teff = (304 ± 11stat ± 40syst) MeV and (407 ± 61stat ± 96syst) MeV respectively. A collective elliptic flow of direct photons is measured and appeared to be close to the decay photon flow.

APA, Harvard, Vancouver, ISO, and other styles

11

Deeg, Andreas, Federico Trigo, Doriane Hazart, Brigitte Delhomme, Tchyia Zar, Thomas Naiser, Christian Seebacher, et al. "Fast, large-field fluorescence and second-harmonic generation imaging with a single-spinning disk two-photon microscope." EPJ Web of Conferences 287 (2023): 03002. http://dx.doi.org/10.1051/epjconf/202328703002.

Full text

Abstract:

Confocal microscopes have been the workhorses of 3-D biological imaging, but they are slow, offer limited depth penetration and collect only ballistic photons. With their inefficient use of excitation photons they expose biological samples to an often intolerably high light burden. The speed limitation and photo-bleaching risk can be somewhat relaxed in a spinning-disk geometry, due to shorter pixel dwell times and rapid re-scans during image capture. Alternatively, light-sheet microscopes rapidly image large volumes of transparent or chemically cleared samples. Finally, with infrared excitation and efficient scattered-light collection, 2-photon microscopy allows deep-tissue imaging, but it remains slow. Here, we describe a new optical scheme that borrows the best from three different worlds: the speed and direct-view from a spinning-disk confocal, deep tissue-penetration and intrinsic optical sectioning from 2-photon excitation, and a large field of view and a low invasiveness of a selective-plane illumination microscope – all with a single objective lens. We validate the performance of our 2-photon spinning-disk microscope in various applications that have in common to simultaneously require a large depth penetration, high speed and larger fields of view. Beyond biological fluorescence, we demonstrate an application in material science, imaging coherent non-linear scattering from a 3-D nano-porous network.

APA, Harvard, Vancouver, ISO, and other styles

12

Rasulov, V. R., R. Ya Rasulov, I. Eshboltaev, and M. X. Kuchkarov. "TO THE THEORY OF THE TWO AND THREE PHOTONIC LINEAR CIRCULAR DICHROISMS IN CUBIC SYMMETRY SEMICONDUCTORS." SEMOCONDUCTOR PHYSICS AND MICROELECTRONICS 3, no. 3 (June 30, 2021): 51–55. http://dx.doi.org/10.37681/2181-1652-019-x-2021-3-9.

Full text

Abstract:

The linear - circular dichroism of two and three photon absorption of light in semiconductors of cubic symmetry of hole conductivity is theoretically investigated. The matrix elements of two and three - photon optical transitions occurring between the subbands of the semiconductor valence band are calculated. In this case, transitions associated with both non - simultaneous absorption of individual photons and simultaneous absorption of two photons are taken into account, and the spectral and temperature dependences of the coefficient of two and three - photon absorption of polarized radiation are determined

APA, Harvard, Vancouver, ISO, and other styles

13

Berger, Ch, and W. Wagner. "Photon photon reactions." Physics Reports 146, no. 1-2 (February 1987): 1–134. http://dx.doi.org/10.1016/0370-1573(87)90012-3.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Radjaroendee, Nattawat, Thammatorn Jamraschai, and Ekapong Hirunsirisawat. "The photon trajectories around black hole with moving light source." Journal of Physics: Conference Series 2653, no. 1 (December 1, 2023): 012024. http://dx.doi.org/10.1088/1742-6596/2653/1/012024.

Full text

Abstract:

Abstract The influence of curved spacetime around a black hole on photon trajectory has been widely studied recently. This study focuses on numerical simulations and some theoretical analysis to characterize the photons emitted from a moving light source around a Schwarzschild black hole. The results show that photon trajectories can be categorized based on the unique features of the light path caused by a variation in emitting angle (β). We propose three types of trajectories, including 1) the return angle (βret ): the photon from this angle orbits around the black hole and returns to the light source 2) the escaping angle (βesc ): the photon from this angle escapes to infinity parallel to the horizontal axis 3) the critical angle (βph ): the photon coming from this angle of initial condition enters a critical photon orbit. The escaped photons can be subclassified by computing the lensed ratio which is the difference between the angular position of the photon escaped to infinity and the initial emitting angle. This study reveals the characteristics of photons from light source moving around a black hole and can be further used to analyze the behavior of light from compact stars or other glowing objects in more complicated systems.

APA, Harvard, Vancouver, ISO, and other styles

15

ZHANG, WENTAO, SIGUO XIAO, XIAOLIANG YANG, and XIANGLIANG JIN. "BROADBAND QUANTUM CUTTING IN ZnO/Yb(Er)F3 OXY-FLUORIDE NANOCOMPOSITE PREPARED BY THERMAL OXIDATION METHOD." Functional Materials Letters 06, no. 01 (February 2013): 1350002. http://dx.doi.org/10.1142/s1793604713500021.

Full text

Abstract:

Yb(Er)F3 nanoparticles absorbed with ZnO sheet were prepared via two-step co-precipitation method followed with thermal oxidation. In the ZnO / Yb(Er)F3 composite phosphor, ZnO can efficiently absorb ultraviolet photons of 250–380 nm and transfer its absorbed photon energy to Er 3+ ions in fluoride particles. A followed quantum cutting between Er 3+- Yb 3+ couples in the fluoride takes place, down-converting an absorbed ultraviolet photon into two photons of 650 nm and 980 nm radiations. The composite phosphor combines the wide wavelength absorption range and high absorption cross-section of ZnO with high quantum cutting efficiency of Er 3+- Yb 3+ co-doped fluoride, showing potential application in the enhancement of Si solar cell efficiency.

APA, Harvard, Vancouver, ISO, and other styles

16

Walborn, S. P., M. P. Almeida, P. H. Souto Ribeiro, and C. H. Monken. "Quantum information processing with hyperentangled photon states." Quantum Information and Computation 6, no. 4&5 (July 2006): 336–50. http://dx.doi.org/10.26421/qic6.4-5-3.

Full text

Abstract:

We discuss quantum information processing with hyperentangled photon states - states entangled in multiple degrees of freedom. Using an additional entangled degree of freedom as an ancilla space, it has been shown that it is possible to perform efficient Bell-state measurements. We briefly review these results and present a novel deterministic quantum key distribution protocol based on Bell-state measurements of hyperentangled photons. In addition, we propose a scheme for a probabilistic controlled-not gate which operates with a 50% success probability. We also show that despite its probabilistic nature, the controlled-not gate can be used for an efficient, nonlocal demonstration of the Deutsch algorithm using two separate photons.

APA, Harvard, Vancouver, ISO, and other styles

17

Htoon, Han. "(Invited) Proximity Induced Chiral Quantum Light Generation in Strain-Engineered WSe₂/NiPS₃ Heterostructures." ECS Meeting Abstracts MA2023-01, no. 10 (August 28, 2023): 1173. http://dx.doi.org/10.1149/ma2023-01101173mtgabs.

Full text

Abstract:

Quantum light emitters (QEs) capable of generating single photons of well-defined circular polarization could enable non-reciprocal single photon devices and deterministic spin-photon interfaces critical for realizing complex quantum networks. To date, emission of such chiral quantum light has been achieved via the application of intense external magnetic fields electrical/optical injection of spin polarized carriers/excitons, or coupling with complex photonic/meta-structures. Here we report free-space generation of highly chiral single photons from QEs created via nanoindentation of monolayer WSe2 - NiPS3 heterostructures at zero external magnetic field. These QEs emit in the 760-800 nm range with a degree of circular polarization and single photon purity as high as 0.89 and 80% respectively, independent of pump laser polarization. Scanning diamond nitrogen vacancy microscopy and temperature dependent magneto-photoluminescence studies reveal that the chiral quantum light emission arises from magnetic proximity interactions between localized excitons in the WSe2 monolayer and the out-of-plane magnetization of defects in antiferromagnetic (AFM) order of NiPS3, both of which are co-localized by the strain field associated with the nanoscale indentations.

APA, Harvard, Vancouver, ISO, and other styles

18

Nomerotski, A., M. Chekhlov, D. Dolzhenko, R. Glazenborg, B. Farella, M. Keach, R. Mahon, D. Orlov, and P. Svihra. "Intensified Tpx3Cam, a fast data-driven optical camera with nanosecond timing resolution for single photon detection in quantum applications." Journal of Instrumentation 18, no. 01 (January 1, 2023): C01023. http://dx.doi.org/10.1088/1748-0221/18/01/c01023.

Full text

Abstract:

Abstract We describe a fast data-driven optical camera, Tpx3Cam, with nanosecond scale timing resolution and 80 Mpixel/sec throughput. After the addition of intensifier, the camera is single photon sensitive with quantum efficiency determined primarily by the intensifier photocathode. The single photon performance of the camera was characterized with results on the gain, timing resolution and afterpulsing reported here. The intensified camera was successfully used for measurements in a variety of applications including quantum applications. As an example of such application, which requires simultaneous detection of multiple photons, we describe registration of photon pairs from the spontaneous parametric down-conversion source in a spectrometer. We measured the photon wavelength and timing with respective precisions of 0.15 nm and 3 ns, and also demonstrated that the two photons are anti-correlated in energy.

APA, Harvard, Vancouver, ISO, and other styles

19

AKSENOV, A. G., R. RUFFINI, I. A. SIUTSOU, and G. V. VERESHCHAGIN. "DYNAMICS AND EMISSION OF MILDLY RELATIVISTIC PLASMA." International Journal of Modern Physics: Conference Series 12 (January 2012): 1–9. http://dx.doi.org/10.1142/s2010194512006204.

Full text

Abstract:

Initially optically thick (with τ = 3⋅107) spherically symmetric outflow consisting of electron-positron pairs and photons is considered. We do not assume thermal equilibrium, and include the two-body processes that occur in such plasma: Möller and Bhabha scattering of pairs, Compton scattering, two-photon pair annihilation, two-photon pair production, together with their radiative three-body variants: bremsstrahlung, double Compton scattering, and three-photon pair annihilation, with their inverse processes. We solve numerically the relativistic Boltzmann equations in spherically symmetric case for distribution functions of pairs and photons. Three epochs are considered in details: a) the thermalization, which brings initially nonequilibrium plasma to thermal equilibrium; b) the self-accelerated expansion, which we find in agreement with previous hydrodynamic studies and c) decoupling of photons from the expanding electron-positron plasma. Photon spectra are computed, and appear to be non thermal near the peak of the luminosity. In particular, the low energy part of the spectrum contain more power with respect to the black body one.

APA, Harvard, Vancouver, ISO, and other styles

20

Pavlov, Victor, Valerii Gridnev, Roman Pisarev, Martin Pohl, Ilya Akimov, Dmitri Yakovlev, and Manfred Bayer. "Femtosecond Photo-Induced Phenomena in Multiferroic Hexagonal Manganite YMnO₃." Solid State Phenomena 233-234 (July 2015): 149–52. http://dx.doi.org/10.4028/www.scientific.net/ssp.233-234.149.

Full text

Abstract:

Transient optical anisotropy in the hexagonal manganite YMnO3excited by linearly and circularly polarized laser pulses has been observed. The photo-induced anisotropy was investigated by the pump-probe technique based on a femtosecond Ti:sapphire laser generating optical pulses at the photon energy of 1.55 eV. Temporal and spectral dependencies of the photo-induced optical rotation and ellipticity were analyzed by a theoretical model considering ultrafast population and relaxation processes near the interband transitions from the hybridized O2−(2p)-Mn3+(3d) (Γ1) to the Mn3+(3d3z2−r2) (Γ5) states at photon energies of the laser excitation. Very short relaxation time of ~10 fs, which is the Raman coherence time between the excited Γ5|x> and Γ5|y> states, has been determined. It is found that this coherence time is much shorter than a charge relaxation time of ~500 fs between the Γ5|x,y> and Γ1|g> states for the interband electronic transition Γ1→Γ5.

APA, Harvard, Vancouver, ISO, and other styles

21

MIKI, KENTARO. "AZIMUTHAL ANISOTROPY MEASUREMENT OF DIRECT PHOTON IN $\sqrt{^SNN} = 200\ {\rm GeV}$Au + Au COLLISIONS AT RHIC-PHENIX." International Journal of Modern Physics E 16, no. 07n08 (August 2007): 2160–65. http://dx.doi.org/10.1142/s0218301307007623.

Full text

Abstract:

Azimuthal anisotropy of direct photons is measured in [Formula: see text] Au + Au collisions by the PHENIX experiment at RHIC. Direct photons are one of the most effective probes to study properties of hot dense medium at initial state (also QGP state) of heavy ion collisions because photons do not interact strongly with medium once produced. They keep their conditions when they are created. Within statistical and systematic errors, the elliptic flow parameter (v2) of direct photons is consistent with zero. Direct photons v2 is measured by the hadron decay photon background v2 from inclusive photon v2 in intermediate to high transverse momentum (pT) region (0 to 10 GeV/c) for 3 centrality selections (20% steps) and minimum bias.

APA, Harvard, Vancouver, ISO, and other styles

22

Shi, Tingting, Yuanbin Fan, Zhengyu Yan, Lai Zhou, Yang Ji, and Zhiliang Yuan. "GHz photon-number resolving detection with high detection efficiency and low noise by ultra-narrowband interference circuits." Journal of Semiconductors 45, no. 3 (March 1, 2024): 032702. http://dx.doi.org/10.1088/1674-4926/45/3/032702.

Full text

Abstract:

Abstract We demonstrate the photon-number resolution (PNR) capability of a 1.25 GHz gated InGaAs single-photon avalanche photodiode (APD) that is equipped with a simple, low-distortion ultra-narrowband interference circuit for the rejection of its background capacitive response. Through discriminating the avalanche current amplitude, we are able to resolve up to four detected photons in a single detection gate with a detection efficiency as high as 45%. The PNR capability is limited by the avalanche current saturation, and can be increased to five photons at a lower detection efficiency of 34%. The PNR capability, combined with high efficiency and low noise, will find applications in quantum information processing technique based on photonic qubits.

APA, Harvard, Vancouver, ISO, and other styles

23

Johnstone, Graeme E., Johannes Herrnsdorf, Martin D. Dawson, and Michael J. Strain. "Efficient Reconstruction of Low Photon Count Images from a High Speed Camera." Photonics 10, no. 1 (December 23, 2022): 10. http://dx.doi.org/10.3390/photonics10010010.

Full text

Abstract:

Challenging imaging applications requiring ultra-short exposure times or imaging in photon-starved environments can acquire extremely low numbers of photons per pixel, (<1 photon per pixel). Such photon-sparse images can require post-processing techniques to improve the retrieved image quality as defined quantitatively by metrics including the Structural Similarity Index Measure (SSIM) and Mean Squared Error (MSE) with respect to the ground truth. Bayesian retrodiction methods have been shown to improve estimation of the number of photons detected and spatial distributions in single-photon imaging applications. In this work, we demonstrate that at high frame rates (>1 MHz) and low incident photon flux (<1 photon per pixel), image post processing can provide better grayscale information and spatial fidelity of reconstructed images than simple frame averaging, with improvements in SSIM up to a factor of 3. Various other image post-processing techniques are also explored and some of which result in a similar quality of image reconstruction to Bayesian retrodiction, with lower computational load. Image reconstructions using Bayesian Retrodiction or bilateral filtering are of comparable quality to frame averaging, as measured by the Structural Similarity Index Measure, when using less than 40% of the photon flux.

APA, Harvard, Vancouver, ISO, and other styles

24

Corsetti, A., R. M. Godbole, and G. Pancheri. "Photon-photon total cross-section." Nuclear Physics B - Proceedings Supplements 71, no. 1-3 (March 1999): 388–91. http://dx.doi.org/10.1016/s0920-5632(98)00370-3.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Shashurin, D. A., E. V. Suslova, V. A. Rozhkov, R. V. Sotenskiy, O. S. Medvedev, and G. A. Shelkov. "Gd2O3–Carbon Nanoflakes (CNFs) as Contrast Agents for Photon-Counting Computed Tomography (PCCT)." Журнал прикладной химии, no. 4 (December 15, 2023): 337–44. http://dx.doi.org/10.31857/s0044461823040023.

Full text

Abstract:

2–3 nm Gd2O3 nanoparticles deposited on carbon nanoflakes were prepared. These are new contrast agents for photon-counting computed tomography based on detectors allowing counting of separate photons. Contrast agents of the Gd2O3@C core–shell structure were prepared by graphitization of the surface of these particles. The Gd2O3 and Gd2O3@C nanoparticles obtained, aqueous solution of Gd(NO3)3·6H2O, and a dispersion of 300–500 nm Gd2O3 particles in gelatin were studied by photon-counting computed tomography. At equal gadolinium concentrations, the highest X-ray absorption was noted for Gd(NO3)3·6H2O and Gd2O3, which is associated with higher density of these samples. Carbon in the contrast agents does not affect the absorption. An algorithm was developed for semiquantitative determination of gadolinium by photon-counting computed tomography.

APA, Harvard, Vancouver, ISO, and other styles

26

Saleh, Gh, Reza Alizadeh, Ehsan Dalili, and Amir Noorbakhsh. "3 Dimensional Motion of Photon and Its Energy." EPJ Web of Conferences 238 (2020): 11015. http://dx.doi.org/10.1051/epjconf/202023811015.

Full text

Abstract:

Since the electron is the photon-generator and the electron is rotating around itself and around the nucleus, the emitted photon from the electron should have the effect of these rotating motions. So, the photon has a three-dimensional motion, including a transition movement and a rotary motion. And it traverses in a helical trajectory. By using this definition, we have proved wave-particle duality at the same time and introduce a new equation for the photon motion and its energy.

APA, Harvard, Vancouver, ISO, and other styles

27

Wilke, R. N., J. Wallentin, M. Osterhoff, D. Pennicard, A. Zozulya, M. Sprung, and T. Salditt. "High-flux ptychographic imaging using the new 55 µm-pixel detector `Lambda' based on the Medipix3 readout chip." Acta Crystallographica Section A Foundations and Advances 70, no. 6 (September 12, 2014): 552–62. http://dx.doi.org/10.1107/s2053273314014545.

Full text

Abstract:

Suitable detection systems that are capable of recording high photon count rates with single-photon detection are instrumental for coherent X-ray imaging. The new single-photon-counting pixel detector `Lambda' has been tested in a ptychographic imaging experiment on solar-cell nanowires using Kirkpatrick–Baez-focused 13.8 keV X-rays. Taking advantage of the high count rate of the Lambda and dynamic range expansion by the semi-transparent central stop, a high-dynamic-range diffraction signal covering more than seven orders of magnitude has been recorded, which corresponds to a photon flux density of about 105 photons nm−2 s−1or a flux of ∼1010 photons s−1on the sample. By comparison with data taken without the semi-transparent central stop, an increase in resolution by a factor of 3–4 is determined: from about 125 nm to about 38 nm for the nanowire and from about 83 nm to about 21 nm for the illuminating wavefield.

APA, Harvard, Vancouver, ISO, and other styles

28

Lin, Tao. "Deferred Optical Photon simulation for the JUNO experiment." Journal of Physics: Conference Series 2438, no. 1 (February 1, 2023): 012078. http://dx.doi.org/10.1088/1742-6596/2438/1/012078.

Full text

Abstract:

Abstract The Jiangmen Underground Neutrino Observatory (JUNO) is designed to determine the neutrino mass ordering and precisely measure oscillation parameters. It is being built in South China at a depth of 700 m underground and comprises a central detector, water Cerenkov detector and top tracker. The central detector is designed to detect anti-neutrinos with an energy resolution of 3% at 1 MeV, using a 20 kt liquid scintillator target with 17,612 20-inch PMTs and 25,600 3-inch PMTs. The scintillator provides a light yield of approximately 10,000 photons per MeV. Monte Carlo simulation is a crucial tool for developing an understanding of detector performance, requiring the production of large samples of background processes with optical photons. Simulation of large numbers of optical photons with Geant4 is computationally challenging for both processing time and memory resources. In order to optimize resource usage, a deferred optical photon simulation workflow is proposed and implemented using Geant4 classes. The key idea is to simulate events initially without optical photons, only performing the optical photon simulation when user specified criteria are met. In this contribution, the design and the implementation of the deferred optical photon simulation will be presented. Optical simulation comprises generation of photons and propagation through the detector implementing optical physics processes including reflection, refraction, scattering and absorption. Instead of generating the optical photons at each step by Geant4 immediately, the necessary data to generate optical photons at each step are collected, which is termed GenStep. At the end of each event, user specified criteria determines if the optical photon simulation is performed using a class called G4OPSimulator. The class G4OPSimulator implements a customized simulation workflow, based on Geant4 internal classes including G4TrackingManager and G4StackManager. The simulator passes references to the collected GenStep objects to customized Scintillation and Cerenkov processes which generate the optical photons in G4Track objects. As a track could be absorbed and re-emitted, the secondaries will be retrieved from the G4TrackingManager and pushed to the G4StackManager. The performance of the simulator will be presented. The technique of deferred optical photon simulation can be applied to all event types and it is expected to be particularly beneficial with rare processes. Especially the events must be selected during the detector simulation at runtime, instead of the event generation. An application of the technique to the simulation of such events will be shown.

APA, Harvard, Vancouver, ISO, and other styles

29

Yang, Ming, Shun An Chen, Qian Ru Lin, and Tao Pang. "Temperature Sensing Assists the Understanding of Er³⁺ Concentration Dependent Anti-Stokes Luminescence in NaYF₄:Er³⁺/Yb³⁺ Nanophosphors." Materials Science Forum 1003 (July 2020): 241–46. http://dx.doi.org/10.4028/www.scientific.net/msf.1003.241.

Full text

Abstract:

In this paper, upcovnerison luminescence in Er3+/Yb3+ co-doped NaYF4 nanophosphors was regulated by changing the Er3+ concentration. With increasing the Er3+ concentration, the green and red emissions increased first and then decreased, but the intensity ratio of red to green emission decreased monotonically. To clarify the role of Er3+ doping, the factors including crystal structure, morphology and size of particle, photon absorption, energy transfer, multi-phonon relaxation, population of emissive levels and emission probability of radiative transitions were considered and analyzed. More importantly, we proposed a simple method for discussing radiation transitions based on luminescence temperature sensing.

APA, Harvard, Vancouver, ISO, and other styles

30

Piston, David W. "Two-Photon Excitation Microscopy in Cellular Biophysics." Proceedings, annual meeting, Electron Microscopy Society of America 54 (August 11, 1996): 276–77. http://dx.doi.org/10.1017/s0424820100163848.

Full text

Abstract:

Two-photon excitation microscopy (TPEM) provides attractive advantages over confocal microscopy for three-dimensionally resolved fluorescence imaging and photochemistry. Two-photon excitation arises from the simultaneous absorption of two photons in a single quantitized event whose probability is proportional to the square of the instantaneous intensity. For example, two red photons can cause the transition to an excited electronic state normally reached by absorption in the ultraviolet. In practice, two-photon excitation is made possible by the very high local instantaneous intensity provided by a combination of diffraction-limited focusing of a single laser beam in the microscope and the temporal concentration of 100 femtosecond pulses generated by a mode-locked laser. Resultant peak excitation intensities are 106 times greater than the CW intensities used in confocal microscopy, but the pulse duty cycle of 10 5 limits the average input power to less than 10 mW, only slightly greater than the power normally used in confocal microscopy.Three properties TPEM give this method a tremendous advantage over conventional optical sectioning microscopies for the study of thick samples: 1) The excitation is limited to the focal volume because of the intensity-squared dependence of the two-photon absorption. This inherent localization provides three-dimensional resolution and eliminates background equivalent to an ideal confocal microscope without requiring a confocal spatial filter, whose absence enhances fluorescence collection efficiency. Confinement of excitation to the focal volume also minimizes photobleaching and photo damage - the ultimate limiting factors in fluorescence microscopy of living cells and tissues. 2) The two-photon technique allows imaging of UV fluorophores with conventional visible light optics in both the scanning and imaging systems, because both the red excitation light (~700 nm) and the blue fluorescence (>400 nm) are within the visible spectrum. 3) Red or infrared light is far less damaging to most living cells and tissues than bluer light because fewer biological molecules absorb at the higher wavelengths. Longer wavelength excitation also reduces scattering of the incident light by the specimen, thus allowing more of the input power to reach the focal plane. This relative transparency of biological specimens to 700 nm light permits deeper sectioning, since both absorbance and scattering are reduced.

APA, Harvard, Vancouver, ISO, and other styles

31

Klinkhamer, F. R. "Lorentz-violating neutral-pion decays in isotropic modified Maxwell theory." Modern Physics Letters A 33, no. 18 (June 14, 2018): 1850104. http://dx.doi.org/10.1142/s0217732318501043.

Full text

Abstract:

We consider an extension of the Standard Model with isotropic non-birefringent Lorentz violation in the photon sector and restrict the discussion to the case of a “fast” photon with a phase velocity larger than the maximum attainable velocity of the quarks and leptons. With our conventions, this case corresponds to a negative Lorentz-violating parameter [Formula: see text] in the action. The decay rate of a neutral pion into two nonstandard photons is calculated as a function of the 3-momentum of the initial pion and the negative Lorentz-violating parameter [Formula: see text] of the final photons.

APA, Harvard, Vancouver, ISO, and other styles

32

Tai, Yuping, Hanying Wang, Hui Wang, and Jintao Bai. "Near-infrared down-conversion in Er3+–Yb3+ co-doped transparent nanostructured glass ceramics for crystalline silicon solar cells." RSC Advances 6, no. 5 (2016): 4085–89. http://dx.doi.org/10.1039/c5ra25800f.

Full text

Abstract:

A two-step energy transfer was achieved in Er³⁺–Yb³⁺ co-doped transparent glass ceramics containing CaF₂ nanocrystals, which involved down-conversion of an absorbed visible photon to two emitted near-infrared photons.

APA, Harvard, Vancouver, ISO, and other styles

33

Scully, Marlan O., and Ulrich W. Rathe. "Vacuum-fluctuation induced photon-photon correlations." Optics Communications 110, no. 3-4 (August 1994): 373–80. http://dx.doi.org/10.1016/0030-4018(94)90441-3.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Beck, Kristin M., Mahdi Hosseini, Yiheng Duan, and Vladan Vuletić. "Large conditional single-photon cross-phase modulation." Proceedings of the National Academy of Sciences 113, no. 35 (August 12, 2016): 9740–44. http://dx.doi.org/10.1073/pnas.1524117113.

Full text

Abstract:

Deterministic optical quantum logic requires a nonlinear quantum process that alters the phase of a quantum optical state by π through interaction with only one photon. Here, we demonstrate a large conditional cross-phase modulation between a signal field, stored inside an atomic quantum memory, and a control photon that traverses a high-finesse optical cavity containing the atomic memory. This approach avoids fundamental limitations associated with multimode effects for traveling optical photons. We measure a conditional cross-phase shift of π/6 (and up to π/3 by postselection on photons that remain in the system longer than average) between the retrieved signal and control photons, and confirm deterministic entanglement between the signal and control modes by extracting a positive concurrence. By upgrading to a state-of-the-art cavity, our system can reach a coherent phase shift of π at low loss, enabling deterministic and universal photonic quantum logic.

APA, Harvard, Vancouver, ISO, and other styles

35

Lederhofer, R., J. Schnakenberg, and H. Stieve. "Stochastic Treatment of Bump Latency and Temporal Overlapping in Limulus Ventral Photoreceptors." Zeitschrift für Naturforschung C 46, no. 3-4 (April 1, 1991): 291–304. http://dx.doi.org/10.1515/znc-1991-3-421.

Full text

Abstract:

We present quantum bumps obtained from flash experiments at the Limulus ventral nerve photoreceptor under voltage clamp conditions. The results are shown and discussed in form of histograms for the latency, amplitude and net charge transfer (current time integral) of the bump current responses. We argue that the experimental latency histogram s cannot be described satisfactorily by chemical models if one assumes that not more than one photon is captured per flash. Instead of, one has to take into account the Poisson statistics of the captures of 0,1,2 ,... photons released by a single flash. We show that the inclusion of Poisson statistics makes the effective latency histograms of flash responses typically asymmetric and skewed to wards short latencies as compared to that of model histograms for one-photon responses. Our conjecture also implies that under our experimental conditions a fraction of up to 20% of the bump responses evoked by a flash should be suspected to be superpositions of two ore more one-photon responses which cannot be separated by any kind of evaluation analysis. Consequently, the average values of amplitudes and net charge transfers of the light-evoked bump responses are expected to be overestimated as compared to that of true one-photon responses. This hypothesis is confirm ed by a numerical simulation of light-evoked bump responses using experimentally recorded spontaneous bumps (at times larger than 1 s after the flash) as the simulation material. We show that the superposition of one-photon events in the light-evoked bump responses due to Poisson statistics settles the question why their amplitudes and net charge transfers are found to be larger than that of the spontaneous bumps. We suggest that true one-photon responses evoked by a light flash and spontaneous bumps start from the same activated rhodopsin state and take the same biochemical pathway.

APA, Harvard, Vancouver, ISO, and other styles

36

González, M. M., D. Avila Rojas, A. Pratts, S. Hernández-Cadena, N. Fraija, R. Alfaro, Y. Pérez Araujo, and J. A. Montes. "GRB 221009A: A Light Dark Matter Burst or an Extremely Bright Inverse Compton Component?" Astrophysical Journal 944, no. 2 (February 1, 2023): 178. http://dx.doi.org/10.3847/1538-4357/acb700.

Full text

Abstract:

Abstract Gamma-ray bursts (GRBs) have been considered as potential very high energy photon emitters due to the large amount of energy released as well as the strong magnetic fields involved in their jets. However, the detection of teraelectronvolt photons is not expected from bursts beyond a redshift of z ≳ 0.1, due to their attenuation with the extragalactic background light (EBL). For these reasons, the recent observation of photons with energies of 18 and 251 TeV from GRB 221009A (z = 0.151) last 2022 October 9 has challenged what we know about the teraelectronvolt-emission mechanisms and the extragalactic background. In order to explain the teraelectronvolt observations, recent works exploring candidates of dark matter have started to appear. In this paper, we discuss the required conditions and limitations within the most plausible scenario, synchrotron self-Compton radiation in the GRB afterglow, to interpret the one 18 TeV photon observation besides the EBL. To avoid the Klein–Nishina effect, we find an improbable value of the microphysical magnetic parameter below 10−6 for a circumburst medium value >1 cm−3 (expected in the collapsar scenario). Therefore, we explore possible scenarios in terms of axion-like particles (ALPs) and dark photon mechanisms to interpret this highly energetic photon and we discuss the implications in the GRB energetics. We find that the ALPs and dark photon scenarios can explain the 18 teraelectronvolt photon but not the 251 teraelectronvolt photon.

APA, Harvard, Vancouver, ISO, and other styles

37

VASEGHI, B., G. REZAEI, and S. KHORSHIDIAN. "NONLINEAR EFFECTS ON THE ENTANGLEMENT BETWEEN QUANTIZED ELECTROMAGNETIC FIELDS AND 3-LEVEL ATOMS." International Journal of Quantum Information 09, no. 07n08 (October 2011): 1653–63. http://dx.doi.org/10.1142/s0219749911008295.

Full text

Abstract:

In this paper, we study the entanglement dynamics, its measure, and mean photon number of the field in the interaction between a quantized electromagnetic field and a 3-level atom surrounded by a nonlinear Kerr-like medium. Using the density matrix approach, we have calculated the time evolution of the entanglement and its magnitude at an arbitrary time, for different nonlinear coupling constant. Moreover, to show the effects of nonlinearity on the atom–field interaction and its relation with the entanglement the mean photon number of the field is also presented as a function of nonlinear coupling strength, χ. The results show that, envelope of entanglement fluctuation, their duration and amplitude strongly depend on the nonlinear coupling strength. Since the entanglement decreases with increasing nonlinearity, the mean number of photons reaches a constant value as a result of absorption increment by the surrounding medium.

APA, Harvard, Vancouver, ISO, and other styles

38

Gómez, Sergio, David Sánchez, Joan Mauricio, Eduardo Picatoste, Andreu Sanuy, Anand Sanmukh, Marc Ribó, and David Gascón. "Multiple Use SiPM Integrated Circuit (MUSIC) for Large Area and High Performance Sensors." Electronics 10, no. 8 (April 17, 2021): 961. http://dx.doi.org/10.3390/electronics10080961.

Full text

Abstract:

The 8-channel Multiple Use Silicon Photo-multiplier (SiPM) Integrated Circuit (MUSIC) Application specific integrated circuit (ASIC) for SiPM anode readout has been designed for applications where large photo-detection areas are required. MUSIC offers three main features: (1) Sum of the eight input channels using a differential output driver, (2) eight individual single ended (SE) analog outputs, and (3) eight individual SE binary outputs using a time over threshold technique. Each functionality, summation and individual readout includes a selectable dual-gain configuration. Moreover, the signal sum implements a dual-gain output providing a 15-bit dynamic range. The circuit contains a tunable pole zero cancellation of the SiPM recovery time constant to deal with most of the available SiPM devices in the market. Experimental tests show how MUSIC can linearly sum signals from different SiPMs and distinguish even a few photons. Additionally, it provides a single photon output pulse width at half maximum (FWHM) between 5–10 ns for the analog output and a single-photon time resolution (SPTR) around 118 ps sigma using a Hamamatsu SiPM S13360-3075CS for the binary output. Lastly, the summation mode has a power consumption of ≈200 mW, whereas the individual readout consumes ≈30 mW/ch.

APA, Harvard, Vancouver, ISO, and other styles

39

Huang, J. P., Y. Q. Xing, and L. Qin. "REVIEW OF NOISE FILTERING ALGORITHM FOR PHOTON DATA." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-3/W10 (February 7, 2020): 105–10. http://dx.doi.org/10.5194/isprs-archives-xlii-3-w10-105-2020.

Full text

Abstract:

Abstract. As a continuation of Ice, Cloud, and Land Elevation Satellite-1 (ICESat-1)/Geoscience Laser Altimeter System (GLAS), the Ice, Cloud, and Land Elevation Satellite-2 (ICESat-2) , which is equipped with the Advanced Topographic Laser Altimeter (ATLAS) system, was successfully launched in 2018. Since ICESat-1/GLAS has facilitated scientific results in the field of forest structure parameter estimation, how to use the ICESat-2/ATLAS photon cloud data to estimate forest structure parameters has become a hotspot in the field of spaceborne photon data application. However, due to the weak photon characteristics of the ICESat-2/ATLAS system, the system is extremely susceptible to noise, which poses a challenge for its subsequent accurate estimation of forest structural parameters. Aiming to filter out the noise photons, the paper introduces the advantages of the spaceborne lidar system ICESat-2/ATLAS than ICESat-1/GLAS. The paper summarizes the research of the simulated photon-counting lidar (PCL) noise filtering algorithm and noise filtering on spaceborne.

APA, Harvard, Vancouver, ISO, and other styles

40

Nguyen, Van Hieu, and Bich Ha Nguyen. "Quantum field theory of interacting plasmon–photon–phonon system." Advances in Natural Sciences: Nanoscience and Nanotechnology 6, no. 3 (April 14, 2015): 035003. http://dx.doi.org/10.1088/2043-6262/6/3/035003.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Piston, David W., Brian D. Bennett, and Guangtao Ying. "Imaging of Cellular Dynamics by Two-Photon Excitation Microscopy." Microscopy and Microanalysis 1, no. 1 (February 1995): 25–34. http://dx.doi.org/10.1017/s1431927695110259.

Full text

Abstract:

Two-photon excitation fluorescence microscopy provides attractive advantages over confocal microscopy for three-dimensionally resolved fluorescence imaging. Two-photon excitation arises from the simultaneous absorption of two photons in a single quantitized event whose probability is proportional to the square of the instantaneous intensity. For example, two red photons (∼700 nm) can cause the transition to an excited electronic state normally reached by absorption in the ultraviolet (∼350 nm). In the fluorescence experiments described here, the final excited state is the same singlet state that is populated during a conventional fluorescence experiment. Thus, the fluorophore exhibits the same emission properties (e.g., wavelength shifts, environmental sensitivity) used in typical biological microscopy studies. Three properties of two-photon excitation give this method its advantage over conventional optical sectioning microscopies: (1) the excitation is limited to the focal volume, thus providing inherent three-dimensional resolution and minimizing photobleaching and photodamage; (2) the two-photon technique allows imaging of UV fluorophores with only conventional visible light optics; (3) red light is far less damaging to most living cells and tissues than UV light and permits deeper sectioning, because both absorbance and scattering are reduced. Many cell biological applications of two-photon excitation microscopy have been successfully realized, demonstrating the wide ranging power of this technique.

APA, Harvard, Vancouver, ISO, and other styles

42

Evans, M. W. "Photon mass and the fieldB (3)." Foundations of Physics Letters 8, no. 3 (June 1995): 279–86. http://dx.doi.org/10.1007/bf02187351.

Full text

APA, Harvard, Vancouver, ISO, and other styles

43

Barnes, Charles, Theodore Tibbitts, John Sager, Gerald Deitzer, David Bubenheim, Gus Koerner, and Bruce Bugbee. "Accuracy of Quantum Sensors Measuring Yield Photon Flux and Photosynthetic Photon Flux." HortScience 28, no. 12 (December 1993): 1197–200. http://dx.doi.org/10.21273/hortsci.28.12.1197.

Full text

Abstract:

Photosynthesis is fundamentally driven by photon flux rather than energy flux, but not all absorbed photons yield equal amounts of photosynthesis. Thus, two measures of photosynthetically active radiation have emerged: photosynthetic photon flux (PPF), which values all photons from 400 to 700 nm equally, and yield photon flux (YPF), which weights photons in the range from 360 to 760 nm according to plant photosynthetic response. We selected seven common radiation sources and measured YPF and PPF from each source with a spectroradiometer. We then compared these measurements with measurements from three quantum sensors designed to measure YPF, and from six quantum sensors designed to measure PPF. There were few differences among sensors within a group (usually <5%), but YPF values from sensors were consistently lower (3 % to 20 %) than YPF values calculated from spectroradiometric measurements. Quantum sensor measurements of PPF also were consistently lower than PPF values calculated from spectroradiometric measurements, but the differences were <7% for all sources, except red-light-emitting diodes. The sensors were most accurate for broad-band sources and least accurate for narrow-band sources. According to spectroradiometric measurement, YPF sensors were significantly less accurate (>9% difference) than PPF sensors under metal halide, high-pressure sodium, and low-pressure sodium lamps. Both sensor types were inaccurate (>18% error) under red-light-emitting diodes. Because both YPF and PPF sensors are imperfect integrators, and because spectroradiometers can measure photosynthetically active radiation much more accurately, researchers should consider developing calibration factors from spectroradiometric data for some specific radiation sources to improve the accuracy of integrating sensors.

APA, Harvard, Vancouver, ISO, and other styles

44

Chumak, Vadim, Elena Bakhanova, Volkan Altunal, Yaacov Lawrence, Sergey Dubinski, Yan Yu, Lydia Liao, and Zehra Yegingil. "Experimental and Monte Carlo study of energy response of BEO-based OSL detectors within photon energy range up to 15 MeV." Radiation Protection Dosimetry 199, no. 15-16 (October 2023): 1829–33. http://dx.doi.org/10.1093/rpd/ncad131.

Full text

Abstract:

Abstract Response of personal dosemeters to high energy photon radiation is of great interest nowadays due to a spread of new radiation technologies and the expansion of occupational exposure domains. ICRU95 publication has expanded the range of relevant photon energies upwards, setting new horizons for individual monitoring. Beryllium oxide (BeO) material is increasingly popular due to its excellent optically stimulated luminescence (OSL) properties, simple readout and reasonable energy response in the low energy (below 100 keV) range. The study considers energy dependence of OSL response at higher photon energies. Energy deposition of monoenergetic photons with energy up to 15 MeV in the BeO chips of various thickness was modeled with Monte Carlo MCNP 6.2 code. Benchmark experiments were conducted at LINAC with high voltage of 6, 10 and 15 MV resulting in respective incident photon spectra. The findings of this study add knowledge regarding behavior of BeO personal dosemeters in the photon fields within the energy range above 3 MeV.

APA, Harvard, Vancouver, ISO, and other styles

45

Salem, N. M. "Thermal Effects of Photon-Phonon Interaction on a Simple Tissue." Environmentalist 25, no. 2-4 (December 2005): 241–46. http://dx.doi.org/10.1007/s10669-005-4289-3.

Full text

APA, Harvard, Vancouver, ISO, and other styles

46

Yin, Bo, Pinshu Lv, Yanmin Yang, and Leipeng Li. "Pr³⁺–Gd³⁺ co-doped Ba₂SiO₄ for multilevel anti-counterfeiting encryption." Journal of Applied Physics 132, no. 15 (October 21, 2022): 153104. http://dx.doi.org/10.1063/5.0119544.

Full text

Abstract:

Developing anti-counterfeiting technology with a higher level of security is vital to boycott the fake commodities. Here, we report the detailed optical property of Ba2SiO4:Pr3+, Gd3+, and their potential applications in fluorescent anti-counterfeit. It has been confirmed that Pr3+ ions could emit the ultraviolet-C (UVC) photons upon excitation of a 450 nm laser, which originates from a two-photon upconverted mechanism. Moreover, the ultraviolet-B (UVB) light also appears simultaneously when co-doping Gd3+ into the host, due to the energy transfer from Pr3+ to Gd3+. Depending on the multimode emissions of Pr3+-Gd3+-codoped phosphors, including the routine magenta emission of Pr3+, as well as the UVC photons of Pr3+ and the UVB light of Gd3+, we successfully achieve multi-level anti-counterfeiting applications.

APA, Harvard, Vancouver, ISO, and other styles

47

Sun, Jia Yue, Yi Ning Sun, Ji Cheng Zhu, Jun Hui Zeng, and Hai Yan Du. "Downconversion for Solar Cells in Sr₃Gd(PO₄)₃:Tb, Yb Phosphors." Advanced Materials Research 502 (April 2012): 136–39. http://dx.doi.org/10.4028/www.scientific.net/amr.502.136.

Full text

Abstract:

An efficient near-infrared (NIR) quantum cutting (QC) Tb3+ and Yb3+ co-doped phosphor Sr3Gd(PO4)3 has been synthesized by conventional high temperature solid technique. Upon excitation of Tb3+ with a visible photon at 485 nm, two NIR photons could be emitted by Yb3+ through cooperative energy transfer (CTE) from Tb3+ to two Yb3+ ions. Excitation and emission spectra as well as ﬂuorescence decay measurements have been carried out to examine the occurrence of cooperative energy transfer (CET ) from Tb3+ to Yb3+ ions. The result indicates Tb3+ and Yb3+ co-doped Sr3Gd(PO4)3 is potentially used as down-converter layer in silicon-based solar cell.

APA, Harvard, Vancouver, ISO, and other styles

48

Chanowitz, Michael S. "Physics at high energy photon photon colliders." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 355, no. 1 (February 1995): 42–49. http://dx.doi.org/10.1016/0168-9002(94)01175-3.

Full text

APA, Harvard, Vancouver, ISO, and other styles

49

Vaidya, V. D., B. Morrison, L. G. Helt, R. Shahrokshahi, D. H. Mahler, M. J. Collins, K. Tan, et al. "Broadband quadrature-squeezed vacuum and nonclassical photon number correlations from a nanophotonic device." Science Advances 6, no. 39 (September 2020): eaba9186. http://dx.doi.org/10.1126/sciadv.aba9186.

Full text

Abstract:

We report demonstrations of both quadrature-squeezed vacuum and photon number difference squeezing generated in an integrated nanophotonic device. Squeezed light is generated via strongly driven spontaneous four-wave mixing below threshold in silicon nitride microring resonators. The generated light is characterized with both homodyne detection and direct measurements of photon statistics using photon number–resolving transition-edge sensors. We measure 1.0(1) decibels of broadband quadrature squeezing (~4 decibels inferred on-chip) and 1.5(3) decibels of photon number difference squeezing (~7 decibels inferred on-chip). Nearly single temporal mode operation is achieved, with measured raw unheralded second-order correlations g(2) as high as 1.95(1). Multiphoton events of over 10 photons are directly detected with rates exceeding any previous quantum optical demonstration using integrated nanophotonics. These results will have an enabling impact on scaling continuous variable quantum technology.

APA, Harvard, Vancouver, ISO, and other styles

50

KADA, W., A. YOKOYAMA, M. KOKA, T. SATOH, and T. KAMIYA. "DEVELOPMENT OF ANALYSIS SYSTEM OF MICRO-IBIL COMBINED WITH MICRO-PIXE." International Journal of PIXE 21, no. 01n02 (January 2011): 1–11. http://dx.doi.org/10.1142/s0129083511002100.

Full text

Abstract:

An ion beam induced luminescence analysis system using ion micro-beam (micro-IBIL) was newly developed on the microbeam system of the 3 MeV single-ended accelerator at ion-irradiation research facility TIARA, JAEA. The developed IBIL system consisted of an aspheric microlens, optical fibers, a monochromator and a photon-counting system to observe IBIL photons of specific wavelength with the resolution of 2 nm. A photomultiplier in the photon-counting system was cooled to around 0°C by a peltier device to reduce the background noises down to 10 cps and able to observe weak photon signals from specific chemical composites of the target. Experiments of micro-IBIL were performed using 3 MeV proton microbeam for several scintillators and particulate targets i.e. aerosol particles. The system had achieved chemical-imaging of aerosols by obtaining wavelength-dispersive micro-IBIL image at luminescence center of silicon dioxide.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic '3 photon'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles