Log in

Relevant bibliographies by topics / State of the photon / Journal articles

To see the other types of publications on this topic, follow the link: State of the photon.

Journal articles on the topic 'State of the photon'

Author: Grafiati

Published: 4 June 2021

Last updated: 14 February 2022

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

Select a source type:

Consult the top 50 journal articles for your research on the topic 'State of the photon.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Ndinya, Boniface Otieno. "Analytical absorption cross section for photon by helium 23s metastable state." Canadian Journal of Physics 91, no. 1 (January 1, 2013): 85–88. http://dx.doi.org/10.1139/cjp-2012-0285.

Full text

Abstract:

We calculate the absorption cross section for photons by the helium 23s metastable state using the quantum–classical approximation for the total photo cross section of many-electron atoms. We note that for the 1s2s configuration of the helium 23S metastable state the photons can be absorbed by either a 1s or 2s electron. The absorption cross section of photons by the 1s and 2s electrons are predominant at high and low energies, respectively. The calculated absorption cross section for a 1s electron agrees perfectly with theoretical results. However, those of the 2s electron do not agree perfectly with experimental and theoretical results, because of the dip associated with the Cooper pair minimum at the zero crossing of the 2s hydrogenic spatial wave function. We have included in the analytical calculation, the second-order term of the Baker–Hausdorff expansion and observed a great reduction in the dip associated with the Cooper pair minimum, at low photon energy.

APA, Harvard, Vancouver, ISO, and other styles

2

AN, NGUYEN BA. "SQUEEZED STATE OF BIEXCITONS IN EXCITED SEMICONDUCTORS." International Journal of Modern Physics B 06, no. 03n04 (February 1992): 395–407. http://dx.doi.org/10.1142/s0217979292000207.

Full text

Abstract:

Exact time-evolution is analytically derived from a coherent photon-exciton system subjected to a monochromatic radiation field resonant with the exciton-biexciton transition. It is shown that biexcitons, which appear under the resonant pumping, might periodically behave as squeezed quasiparticles, if photons or/and excitons are initially in squeezed states. The squeezing degree of the initial photons or/and excitons, the pumping intensity and the off-resonance detuning are demonstrated to govern the transfer of squeezing from the photon-exciton system to the biexciton.

APA, Harvard, Vancouver, ISO, and other styles

3

Sun, Shu Feng. "Fabrication Technology of Involute Micro Gear Based on Two-Photon of Femtosecond Laser." Applied Mechanics and Materials 44-47 (December 2010): 670–74. http://dx.doi.org/10.4028/www.scientific.net/amm.44-47.670.

Full text

Abstract:

Microfabrication is a kind of critical technology for the development of Micro Electro-Mechanical Systems (MEMS). The frequently-used microfabrication technologies are electric discharge machining, photoetching, LIGA and laser fabrication, et al. Micro structures may be fabricated by these technologies. The polymerization principle of two-photon of femtosecond laser is different from that of single-photon. Photoinitiator of photosensing material absorbs two photons simultaneously to accomplish energy level transition and to induce the material to occur photochemical reaction. For the material absorbing two photons, the energy of each photon is equivalent to half of the energy that needed by the material transiting from ground state to excited state. It is also equal to half of the energy needed by the material occurring single-photon absorption. Therefore, the photonic frequency of two-photon excitation light source is half of the single-photon light source. According to two-photon fabrication principle, machining system of two-photon of femtosecond laser is set up. Which includes light path transmission equipment, three dimensional micro displacement scanning stage and control software, et al. Involute micro gear is fabricated by two-photon of femtosecond laser generated by the system.

APA, Harvard, Vancouver, ISO, and other styles

4

Cheng, Ze. "Thermodynamic properties of coherent photons in self-focusing nonlinear waveguides." Journal of Nonlinear Optical Physics & Materials 28, no. 01 (March 2019): 1950006. http://dx.doi.org/10.1142/s0218863519500061.

Full text

Abstract:

We study the thermodynamic properties of coherent photons in self-focusing nonlinear waveguides. The equation of the superfluid state of photons has been derived. There is a transition temperature [Formula: see text], above which the photon gas is in the coherent state, but below which the photon gas is in the superfluid state. At [Formula: see text], the photon system undergoes a first-order phase transition from the coherent to the superfluid state. To determine the fugacity [Formula: see text] and the transition temperature [Formula: see text] of the photon gas, we numerically solve the equation of the superfluid state of photons. The fugacity [Formula: see text] is a monotonically decreasing function of temperature [Formula: see text] and light intensity [Formula: see text]. The transition temperature [Formula: see text] is a monotonically decreasing function of light intensity [Formula: see text].

APA, Harvard, Vancouver, ISO, and other styles

5

Sun, Shuo, Hyochul Kim, Zhouchen Luo, Glenn S. Solomon, and Edo Waks. "A single-photon switch and transistor enabled by a solid-state quantum memory." Science 361, no. 6397 (July 5, 2018): 57–60. http://dx.doi.org/10.1126/science.aat3581.

Full text

Abstract:

Single-photon switches and transistors generate strong photon-photon interactions that are essential for quantum circuits and networks. However, the deterministic control of an optical signal with a single photon requires strong interactions with a quantum memory, which has been challenging to achieve in a solid-state platform. We demonstrate a single-photon switch and transistor enabled by a solid-state quantum memory. Our device consists of a semiconductor spin qubit strongly coupled to a nanophotonic cavity. The spin qubit enables a single 63-picosecond gate photon to switch a signal field containing up to an average of 27.7 photons before the internal state of the device resets. Our results show that semiconductor nanophotonic devices can produce strong and controlled photon-photon interactions that could enable high-bandwidth photonic quantum information processing.

APA, Harvard, Vancouver, ISO, and other styles

6

Su, Xi-Rong, Yi-Wen Huang, Tong Xiang, Yuan-Hua Li, and Xian-Feng Chen. "Generation of Pure State Photon Triplets in the C-Band." Micromachines 10, no. 11 (November 13, 2019): 775. http://dx.doi.org/10.3390/mi10110775.

Full text

Abstract:

In this work, the cascaded second-order spontaneous parametric down-conversion (SPDC) is considered to produce pure state photon triplets in periodically poled lithium niobite (PPLN) doped with 5% MgO. A set of parameters are optimized through calculating the Schmidt number of two-photon states generated by each down-conversion process with different pump durations and crystal lengths. We use a Gaussian filter in part and obtain three photons with 100% purity in spectrum. We provide a feasible and unprecedented scheme to manipulate the spectrum purity of photon triplets in the communication band (C-band).

APA, Harvard, Vancouver, ISO, and other styles

7

SHAO, YANG, YAN-HUI ZHOU, and AI-DONG ZHU. "NONLOCAL CLONING FOR A STATE NEAR A GIVEN ONE WITH SINGLE-PHOTON INTERFERENCE." International Journal of Quantum Information 07, no. 07 (October 2009): 1331–36. http://dx.doi.org/10.1142/s0219749909005663.

Full text

Abstract:

A linear optical scheme is proposed for implementing a nonlocal cloning machine which copies a state near a given one with single-photon interference. We combine the advantages of photons and atoms by adopting two three level atoms as the storing qubits and a polarized photon as the flying qubit, and the photon loss events are also considered. With our present scheme, a high-fidelity cloning machine is realized at the expense of the success probability.

APA, Harvard, Vancouver, ISO, and other styles

8

HANKS, ALI. "MEASURING BREMSSTRAHLUNG PHOTONS IN $\sqrt{S} = 200\ {\rm GeV}$p-p COLLISIONS." International Journal of Modern Physics E 16, no. 07n08 (August 2007): 2182–86. http://dx.doi.org/10.1142/s0218301307007659.

Full text

Abstract:

Direct photon production is an important observable in heavy ion collisions, as photons are penetrating and therefore largely insensitive to final state effects. Measurements of the fragmentation component of direct photon yields in p + p and Au + Au collisions will provide important tests of pQCD predictions and of predictions for modifications of this component in heavy ion collisions. By selecting photons associated with jets on the same side using hadron-photon correlations, fragmentation photons can be measured directly.

APA, Harvard, Vancouver, ISO, and other styles

9

Fanchiotti, H., C. A. García Canal, and V. Vento. "Multiphoton annihilation of monopolium." International Journal of Modern Physics A 32, no. 35 (December 20, 2017): 1750202. http://dx.doi.org/10.1142/s0217751x17502025.

Full text

Abstract:

We show that due to the large coupling constant of the monopole–photon interaction the annihilation of monopole–antimonopole and monopolium into many photons must be considered experimentally. For monopole–antimonopole annihilation and lightly bound monopolium, even in the less favorable scenario, multiphoton events (four and more photons in the final state) are dominant, while for strongly bound monopolium, although two photon events are important, four- and six-photon events are also sizable.

APA, Harvard, Vancouver, ISO, and other styles

10

Kiesel, Nikolai, Mohamed Bourennane, Christian Kurtsiefer, Harald Weinfurter, D. Kaszlikowski, W. Laskowski, and Marek Zukowski. "Three-photon W-state." Journal of Modern Optics 50, no. 6-7 (April 2003): 1131–38. http://dx.doi.org/10.1080/09500340308234557.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

Fitzgerald, Richard J. "Solid-state photon storage." Physics Today 62, no. 2 (February 2009): 23. http://dx.doi.org/10.1063/1.4797061.

Full text

APA, Harvard, Vancouver, ISO, and other styles

12

Keller, T. E., M. H. Rubin, and Y. H. Shih. "Three-Photon Entangled State." Fortschritte der Physik 46, no. 6-8 (November 1998): 673–82. http://dx.doi.org/10.1002/(sici)1521-3978(199811)46:6/8<673::aid-prop673>3.0.co;2-y.

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Inoue, J., and K. Ohtaka. "Photon virtual bound state." Journal of Luminescence 108, no. 1-4 (June 2004): 251–54. http://dx.doi.org/10.1016/j.jlumin.2004.01.053.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Abdullah, Nzar Rauf, Chi-Shung Tang, Andrei Manolescu, and Vidar Gudmundsson. "Thermoelectric Inversion in a Resonant Quantum Dot-Cavity System in the Steady-State Regime." Nanomaterials 9, no. 5 (May 14, 2019): 741. http://dx.doi.org/10.3390/nano9050741.

Full text

Abstract:

We theoretically investigate thermoelectric effects in a quantum dot system under the influence of a linearly polarized photon field confined to a 3D cavity. A temperature gradient is applied to the system via two electron reservoirs that are connected to each end of the quantum dot system. The thermoelectric current in the steady state is explored using a quantum master equation. In the presence of the quantized photons, extra channels, the photon replica states, are formed generating a photon-induced thermoelectric current. We observe that the photon replica states contribute to the transport irrespective of the direction of the thermal gradient. In the off-resonance regime, when the energy difference between the lowest states of the quantum dot system is smaller than the photon energy, the thermoelectric current is almost blocked and a plateau is seen in the thermoelectric current for strong electron–photon coupling strength. In the resonant regime, an inversion of thermoelectric current emerges due to the Rabi-splitting. Therefore, the photon field can change both the magnitude and the sign of the thermoelectric current induced by the temperature gradient in the absence of a voltage bias between the leads.

APA, Harvard, Vancouver, ISO, and other styles

15

Hoai, Nguyen Thi Xuan, and Truong Minh Duc. "Nonclassical properties and teleportation in the two-mode photon-added displaced squeezed states." International Journal of Modern Physics B 30, no. 07 (March 18, 2016): 1650032. http://dx.doi.org/10.1142/s0217979216500326.

Full text

Abstract:

In this paper, we study the nonclassical properties and find out the effect of photon addition on these properties as well as the process of teleportation in the two-mode photon-added displaced squeezed (TMPADS) states. We derive the analytic expressions of the Wigner function, the photon number distribution and the intermode photon antibunching for these states. We show that photon addition operation not only makes the Wigner function become negative but also leads to increase the degree of antibunching. The peak of the photon number distribution becomes flatter and shifts to the greater number of photons by adding photons to both modes simultaneously. Furthermore, it is proved that the degree of intermodal entanglement becomes bigger and bigger through increasing the number of photons added to both modes. As expected, when using these states as an entanglement resource to teleport a state, the average fidelity of teleportation process is also improved by increasing the number of added photons.

APA, Harvard, Vancouver, ISO, and other styles

16

Martin, Tchoffo, Tene Alain Giresse, and Djebayole Mimbe III Yannick. "Triggering parametric-down conversion-based quantum key distribution via radiation field." International Journal of Quantum Information 18, no. 06 (September 2020): 2050037. http://dx.doi.org/10.1142/s0219749920500379.

Full text

Abstract:

We discuss the influence of radiation field on the secure key size and the maximum safety distance during QKD by using a set of photons produced via a spontaneous parametric-down conversion (SPDC) photon source. Four implementations that use multiple-photons and decoy states are discussed, these include nondecoy state, infinite active decoy state, passive decoy state with threshold detector and passive decoy state with perfect photon-number resolving detector. Results show that the radiation field significantly improves both the secure key size and the maximum secure communication distance. Therefore, the radiation field is found to be a good candidate to reduce unwanted interactions of photons with the quantum channel and hence, to increase the secure key rate and the maximum safety distance between legitimate users.

APA, Harvard, Vancouver, ISO, and other styles

17

Yatsui, Takashi, Wataru Nomura, Fabrice Stehlin, Olivier Soppera, Makoto Naruse, and Motoichi Ohtsu. "Challenges in realizing ultraflat materials surfaces." Beilstein Journal of Nanotechnology 4 (December 11, 2013): 875–85. http://dx.doi.org/10.3762/bjnano.4.99.

Full text

Abstract:

Ultraflat surface substrates are required to achieve an optimal performance of future optical, electronic, or optoelectronic devices for various applications, because such surfaces reduce the scattering loss of photons, electrons, or both at the surfaces and interfaces. In this paper, we review recent progress toward the realization of ultraflat materials surfaces. First, we review the development of surface-flattening techniques. Second, we briefly review the dressed photon–phonon (DPP), a nanometric quasiparticle that describes the coupled state of a photon, an electron, and a multimode-coherent phonon. Then, we review several recent developments based on DPP-photochemical etching and desorption processes, which have resulted in angstrom-scale flat surfaces. To confirm that the superior flatness of these surfaces that originated from the DPP process, we also review a simplified mathematical model that describes the scale-dependent effects of optical near-fields. Finally, we present the future outlook for these technologies.

APA, Harvard, Vancouver, ISO, and other styles

18

PESTIEAU, J., and C. SMITH. "A NEW BASIS FOR QED BOUND STATE COMPUTATIONS." International Journal of Modern Physics A 17, no. 28 (November 10, 2002): 4113–32. http://dx.doi.org/10.1142/s0217751x02011412.

Full text

Abstract:

A simple method to compute QED bound state properties is presented, in which binding energy effects are treated nonperturbatively. It is shown that to take the effects of all ladder Coulomb photon exchanges into account, one can simply perform the derivative of standard QED amplitudes with respect to the external momentum. For example, the derivative of the light-by-light scattering amplitude gives an amplitude for orthopositronium decay to three photons where any number of Coulomb photon exchanges between the e+e-is included.Various applications are presented. From them, it is shown that binding energy must be treated nonperturbatively in order to preserve the analyticity of positronium decay amplitudes.Interesting perspectives for quarkonium physics are briefly sketched.

APA, Harvard, Vancouver, ISO, and other styles

19

Williams, J. F., A. G. Mikosza, and J. B. Wang. "Review of advances in describing the 31D-state excitation of helium." Canadian Journal of Physics 74, no. 11-12 (November 1, 1996): 906–13. http://dx.doi.org/10.1139/p96-806.

Full text

Abstract:

Recent advances in describing the electron impact excitation of the 31D state of helium are reported for an incident energy of 40 eV and scattering angles from 10° to 40°. Measurements of the Stokes parameters have been made using the polarized photon–photon and electron–photon coincidence techniques. The partial cross section σm for the magnetic sublevels in the collision frame indicate that the m = 0 excitation is favoured. For the above scattering kinematics the data are in agreement with convergent close coupling calculations. The deduced scattering amplitudes, in the natural frame, show that the m = 2 excitation becomes dominant at the larger angles. Progress is reported on the complete determination of the scattering amplitudes and their relative phases using the triple-coincident detection of the scattered electron with the two sequential cascading photons.

APA, Harvard, Vancouver, ISO, and other styles

20

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

21

XU, TING-TING, WEI XIONG, and LIU YE. "CONCENTRATING ARBITRARY FOUR-PHOTON LESS-ENTANGLED CLUSTER STATE BY SINGLE PHOTONS." Modern Physics Letters B 26, no. 32 (November 15, 2012): 1250214. http://dx.doi.org/10.1142/s0217984912502144.

Full text

Abstract:

We present a protocol for concentrating an arbitrary four-photon entangled state into a maximally entangled state assisted with singled photons. The concentration protocol uses the linear optics and the cross-Kerr nonlinearity based on the post selection principle. Four parties called Alice, Bob, Charlie and Dan in different distant locations can obtain the cluster state from an arbitrary entangled four-photon state with a certain probability. Quantum non-demolition (QND) measurements are available in this protocol. Moreover, this scheme can be steady with a higher success possibility.

APA, Harvard, Vancouver, ISO, and other styles

22

Royon, C., and M. Saimpert. "Photon induced processes at the LHC." International Journal of Modern Physics A 29, no. 28 (November 10, 2014): 1446016. http://dx.doi.org/10.1142/s0217751x14460166.

Full text

Abstract:

We discuss the photon-induced processes that can be studied at the LHC, leading to intact protons in the final state. We give the SM cross-section for W- and photon-pair production. These processes lead to unprecedented sensitivities on quartic anomalous couplings between photons and W and Z bosons, reaching the values expected for extra dimension models.

APA, Harvard, Vancouver, ISO, and other styles

23

Kotwal, Ashutosh V., and Bodhitha Jayatilaka. "Comparison of horace and photos Algorithms for Multiphoton Emission in the Context ofWBoson Mass Measurement." Advances in High Energy Physics 2016 (2016): 1–9. http://dx.doi.org/10.1155/2016/1615081.

Full text

Abstract:

Wboson mass measurement is sensitive to QED radiative corrections due to virtual photon loops and real photon emission. The largest shift in the measured mass, which depends on the transverse momentum spectrum of the charged lepton from the boson decay, is caused by the emission of real photons from the final-state lepton. There are a number of calculations and codes available to model the final-state photon emission. We perform a detailed study, comparing the results fromhoraceandphotosimplementations of the final-state multiphoton emission in the context of a direct measurement ofWboson mass at Tevatron. Mass fits are performed using a simulation of the CDF II detector.

APA, Harvard, Vancouver, ISO, and other styles

24

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

25

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

26

Thekkadath, G. S., B. A. Bell, I. A. Walmsley, and A. I. Lvovsky. "Engineering Schrödinger cat states with a photonic even-parity detector." Quantum 4 (March 2, 2020): 239. http://dx.doi.org/10.22331/q-2020-03-02-239.

Full text

Abstract:

When two equal photon-number states are combined on a balanced beam splitter, both output ports of the beam splitter contain only even numbers of photons. Consider the time-reversal of this interference phenomenon: the probability that a pair of photon-number-resolving detectors at the output ports of a beam splitter both detect the same number of photons depends on the overlap between the input state of the beam splitter and a state containing only even photon numbers. Here, we propose using this even-parity detection to engineer quantum states containing only even photon-number terms. As an example, we demonstrate the ability to prepare superpositions of two coherent states with opposite amplitudes, i.e. two-component Schrödinger cat states. Our scheme can prepare cat states of arbitrary size with nearly perfect fidelity. Moreover, we investigate engineering more complex even-parity states such as four-component cat states by iteratively applying our even-parity detector.

APA, Harvard, Vancouver, ISO, and other styles

27

Xie, Dong, and An Min Wang. "Generation of multi-photon entanglement." International Journal of Quantum Information 13, no. 03 (April 2015): 1550018. http://dx.doi.org/10.1142/s0219749915500185.

Full text

Abstract:

We propose a new scheme to generate multi-photon entanglement in two steps. First, we utilize a superconductor to create multi-quantum-dot entanglement; secondly, we use the input photon to transfer it into multi-photon entanglement. Moreover, the maximum probability for the swap of photon and quantum-dot qubits is close to unity for a single input Gaussian photon. More importantly, by mapping the multi-quantum-dot state into coherent states of oscillators, such as cavity modes, the multi-quantum-dot entanglement in our scheme can be protected from the decoherence induced by the noise. Thus, it is possible to generate more than eight spatially separated entangled photons in the realistic experimental conditions.

APA, Harvard, Vancouver, ISO, and other styles

28

Piston, David W. "Two-photon excitation fluorescence microscopy in living systems." Proceedings, annual meeting, Electron Microscopy Society of America 51 (August 1, 1993): 154–55. http://dx.doi.org/10.1017/s0424820100146618.

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 can cause the transition to an excited electronic state normally reached by absorption in the ultraviolet. In our fluorescence experiments, 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. 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 maintains the average input power on the order of 10 mW, only slightly greater than the power normally used in confocal microscopy.

APA, Harvard, Vancouver, ISO, and other styles

29

Bao, Yanjun, Qiaoling Lin, Rongbin Su, Zhang-Kai Zhou, Jindong Song, Juntao Li, and Xue-Hua Wang. "On-demand spin-state manipulation of single-photon emission from quantum dot integrated with metasurface." Science Advances 6, no. 31 (July 2020): eaba8761. http://dx.doi.org/10.1126/sciadv.aba8761.

Full text

Abstract:

The semiconductor quantum dot (QD) has been successfully demonstrated as a potentially scalable and on-chip integration technology to generate the triggered photon streams that have many important applications in quantum information science. However, the randomicity of these photon streams emitted from the QD seriously compromises its use and especially hinders the on-demand manipulation of the spin states. Here, by accurately integrating a QD and its mirror image onto the two foci of a bifocal metalens, we demonstrate the on-demand generation and separation of the spin states of the emitted single photons. The photon streams with different spin states emitted from the QD can be flexibly manipulated to propagate along arbitrarily designed directions with high collimation of the smallest measured beaming divergence angle of 3.17°. Our work presents an effectively integrated quantum method for the simultaneously on-demand manipulation of the polarization, propagation, and collimation of the emitted photon streams.

APA, Harvard, Vancouver, ISO, and other styles

30

Ghimire, Bal Ram. "Study of two-photon absorption and optical limiting." BIBECHANA 18, no. 2 (February 9, 2021): 26–31. http://dx.doi.org/10.3126/bibechana.v18i2.34838.

Full text

Abstract:

Simultaneous absorption of two photons of identical or different frequencies to excite a system that is atom or molecule from the ground state to excited state has great importance. It has an important role as a spectroscopic tool for determining the positions of energy levels that are not connected to the atomic ground state by the one-photon transition. In this work, experimental study of two-photon absorption of fused silica, quartz crystal, and metal halides and optical limiters based on the semiconductors are studied. It was investigated that two photons absorption depletes the transmitted beam but carrier defocusing spreads the beam in space and hence density is reduced. It was realized that limiters with thin samples have low dynamic range and fluency is high on the damage-prone surface and irreversible damage occurs. Some Semiconductors with high nonlinearity are found to be useful materials for optical limiters to protect devices like sensors. BIBECHANA 18 (2) (2021) 26-31

APA, Harvard, Vancouver, ISO, and other styles

31

Yuan, Hong-Chun, Xue-Xiang Xu, Heng-Mei Li, Ye-Jun Xu, and Xiang-Guo Meng. "Photon-catalyzed optical coherent states generated via a non-degenerate parametric amplifier with quantum-optical catalysis." Canadian Journal of Physics 98, no. 2 (February 2020): 119–24. http://dx.doi.org/10.1139/cjp-2019-0001.

Full text

Abstract:

We theoretically generate a kind of photon-catalyzed optical coherent states (PCOCSs) by heralded interference between any photons and coherent state via a non-degenerate parametric amplifier, which is also just a Laguerre polynomial excited coherent state. Based on obtaining the probability of successfully detecting them (also the normalization factor), the nonclassical properties of the PCOCSs are analytically investigated according to autocorrelation function, quadrature squeezing, and the negativity of the Wigner function. It is found that the nonclassicality depends on the amplitude of the coherent state, the catalysis photon number, and amplifier parameter. The negative volume of their Wigner function can be enlarged by increasing the catalysis photon number. These parameters may be effectively used to improve and enhance the nonclassical characteristics.

APA, Harvard, Vancouver, ISO, and other styles

32

Buchal, Ch, and M. Löken. "Silicon-Based Metal-Semiconductor-Metal Detectors." MRS Bulletin 23, no. 4 (April 1998): 55–59. http://dx.doi.org/10.1557/s088376940003027x.

Full text

Abstract:

Photodetectors must provide fast and efficient conversion of photons to charge carriers. When considering semiconductor light sources, the indirect bandgap of silicon and germanium represents a serious obstacle to radiative electron-hole recombinations. Momentum conservation demands the simultaneous interaction of the electron-hole pair with a momentum-matching phonon. As a consequence, radiative recombinations are five orders of magnitude less probable in Si if compared to a direct semiconductor such as GaAs.Although the absorption of a photon and the generation of an electron-hole pair may be considered as the inverse process to emission, photon absorption within indirect semiconductors is a highly probable process if the photon energy is sufficient to bridge the energy gap in a direct process. The resulting electronhole pair is created in an excited state and relaxes sequentially. The ubiquitous-silicon solar cells operate this way. In the visible spectral range, Si photodetectors have demonstrated fast and efficient performance, being readily adapted for opto electronic applications and being fully compatible to standard-silicon processing schemes.

APA, Harvard, Vancouver, ISO, and other styles

33

Aharonovich, Igor, Dirk Englund, and Milos Toth. "Solid-state single-photon emitters." Nature Photonics 10, no. 10 (September 29, 2016): 631–41. http://dx.doi.org/10.1038/nphoton.2016.186.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Zappa, Franco. "Solid‐state single‐photon detectors." Optical Engineering 35, no. 4 (April 1, 1996): 938. http://dx.doi.org/10.1117/1.600702.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

D'Ariano, G. M., L. Maccone, M. G. A. Paris, and M. F. Sacchi. "State Preparation by Photon Filtering." Fortschritte der Physik 48, no. 5-7 (May 2000): 671–78. http://dx.doi.org/10.1002/(sici)1521-3978(200005)48:5/7<671::aid-prop671>3.0.co;2-g.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

Petroff, M. D., and M. G. Stapelbroek. "Photon-counting solid-state photomultiplier." IEEE Transactions on Nuclear Science 36, no. 1 (1989): 158–62. http://dx.doi.org/10.1109/23.34424.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

GAUTHIER, D. J., Q. WU, S. E. MORIN, and T. W. MOSSBERG. "DRESSED-STATE TWO-PHOTON LASER." Optics and Photonics News 2, no. 12 (December 1, 1991): 12. http://dx.doi.org/10.1364/opn.2.12.000012.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Saleh, Bahaa E. A., Bradley M. Jost, Hong-Bing Fei, and Malvin C. Teich. "Entangled-Photon Virtual-State Spectroscopy." Physical Review Letters 80, no. 16 (April 20, 1998): 3483–86. http://dx.doi.org/10.1103/physrevlett.80.3483.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Dai, Q., and H. Jing. "Photon-Added Entangled Coherent State." International Journal of Theoretical Physics 47, no. 10 (March 25, 2008): 2716–21. http://dx.doi.org/10.1007/s10773-008-9710-5.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Keller, O. "Photon wave mechanics in the eikonal limit: Diamagnetic field-plasma interaction." Laser and Particle Beams 26, no. 2 (June 2008): 287–94. http://dx.doi.org/10.1017/s0263034608000359.

Full text

Abstract:

AbstractA microscopic eikonal theory based on photon wave mechanics is established. The diamagnetic (solid state) field-plasma interaction is shown to play a central role in the theory, and this interaction enables one to introduce a massive transverse photon concept. This quasi-particle enters the eikonal theory in manner similar to the one in which the classical point particle enters Newtonian Mechanics in the Hamilton-Jacobi formulation. When the spatial fluctuations in the stationary-state plasma density are of importance the microscopic eikonal theory becomes a spatially nonlocal theory, and the nonlocality, originating in the coupling of longitudinal and scalar photons to the massive transverse photon, extends over near-field distances.

APA, Harvard, Vancouver, ISO, and other styles

41

Kylafis, Nikolaos D., and Pablo Reig. "Correlation of time lag and photon index in GX 339-4." Astronomy & Astrophysics 614 (June 2018): L5. http://dx.doi.org/10.1051/0004-6361/201833339.

Full text

Abstract:

Context. Black hole transients, as a class, exhibit during their outbursts a correlation between the time lag of hard photons with respect to softer ones and the photon index of the hard X-ray power law. The correlation is not very tight and therefore it is necessary to examine it source by source. Aims. The objective of the present work is to investigate in detail the correlation between the time lag and the photon index in GX 339-4, which is the best studied black hole transient. Methods. We have obtained RXTE energy spectra and light curves and have computed the photon index and the time lag of the 9–15 keV photons with respect to the 2–6 keV photons. The observations cover the first stages of the hard state, the pure hard state, and the hard-intermediate state. Results. We have found a tight correlation between time lag and photon index Γ in the hard and hard-intermediate states. At low Γ, the correlation is positive; it becomes negative at high Γ By assuming that the hard X-ray power-law index Γ is produced by inverse Compton scattering of soft disk photons in the jet, we have reproduced the entire correlation by varying two parameters in the jet: the radius of the jet at its base R0 and the Thomson optical depth along the jet τ∥. We have found that as the luminosity of the source increases, R0 initially increases and then decreases. This behavior is expected in the context of the Cosmic Battery. Conclusions. Our jet model nicely explains the correlation with reasonable values of the parameters R0 and τ∥ These parameters also correlate between themselves. As a further test of our model, we predict the break frequency in the radio spectrum as a function of the photon index during the rising part of an outburst.

APA, Harvard, Vancouver, ISO, and other styles

42

Liu, Nai-le, Zhi-hu Sun, and Hong-yi Fan. "Photon-added squeezed vacuum (one-photon) state as an even (odd) nonlinear coherent state." Journal of Physics A: Mathematical and General 33, no. 9 (February 28, 2000): 1933–40. http://dx.doi.org/10.1088/0305-4470/33/9/315.

Full text

APA, Harvard, Vancouver, ISO, and other styles

43

Lu, Hong. "Photon Statistics of Photon-Added and Photon-Subtracted Two-Mode Squeezed Vacuum State." Chinese Physics Letters 16, no. 9 (September 1, 1999): 646–47. http://dx.doi.org/10.1088/0256-307x/16/9/009.

Full text

APA, Harvard, Vancouver, ISO, and other styles

44

Piston, David W., James H. Strickler, and Watt W. Webb. "Application of two-photon chromophore excitation to laser scanning microscopy." Proceedings, annual meeting, Electron Microscopy Society of America 49 (August 1991): 404–5. http://dx.doi.org/10.1017/s0424820100086325.

Full text

Abstract:

The non-linear optical technique of two-photon excitation of fluorescence and photochemical reactions makes possible new applications that are not possible using linear one-photon excitation in laser scanning confocal microscopy. The two-photon excitation effect arises from the simultaneous absorption of two red photons, which causes the transition to an excited electronic state with its normal absorption in the ultraviolet. In our fluorescence experiments, this excited state is the same singlet state, S1, that is populated during a conventional fluorescence experiment, and thus exhibits the same emission properties (e.g. wavelength shifts, environmental sensitivity) that are observed in typical biological microscopy studies. Likewise, photochemical reactions such as light induced polymerization and photolytic uncaging that are normally catalyzed by UV light can be generated using two-photon excitation. In practice, twophoton excitation is made possible by the very high local instantaneous intensity that is provided by a combination of the diffraction limited focusing in the microscope and the temporal concentration of a subpicosecond mode-locked laser.

APA, Harvard, Vancouver, ISO, and other styles

45

Mir, Mubben A. "Photon Statistics and Squeezing in the Two-Atom Thermal Jaynes-Cummings Model." International Journal of Modern Physics B 12, no. 26 (October 20, 1998): 2743–55. http://dx.doi.org/10.1142/s0217979298001599.

Full text

Abstract:

The behavior of the mean photon number, photon number variance and field squeezing is investigated for the two two-level atoms prepared in a multiatom squeezed state coupled to the vacuum or thermal field. The value of superposition angle (θ) of the atomic states is found to affect the photon number variance as well as field squeezing. The bound on the sun-Poissonian field concerning the value of θ and input mean photon number is determined. One of the field quadrature is found to exhibit permanent squeezing for the vacuum input in a small range of the value of θ. It is shown that the input thermal photons degrade the sub-Poissonian character and spontaneous squeezing. However, a considerable amount of squeezing is obtained even in the presence of thermal photons.

APA, Harvard, Vancouver, ISO, and other styles

46

Xu, Xue-Xiang, and Hong-Chun Yuan. "Coherent state truncation by conditional interferometry." Modern Physics Letters A 35, no. 19 (May 15, 2020): 2050158. http://dx.doi.org/10.1142/s0217732320501588.

Full text

Abstract:

Based on a conditional interferometry proposed by Paris [Phys. Rev. A 62, 033813 (2000)], we prepare any chosen superposition of the vacuum, one-photon, and two-photon states, which is truncating from an input coherent state. Feeding two perfect single-photon states and a coherent state into the interferometry and employing two one-photon detections, the conditional state can be obtained in the signal port. Ideal and realistic features of the one-photon counting are taken into account together with the effect on the fidelity between the ideal state and the realistic case. The ideal state is just a particular case of the realistic state with the unit efficiency. We study the antibunching effect and Wigner function of the generated states. The results show that the generated states will exhibit their specular character.

APA, Harvard, Vancouver, ISO, and other styles

47

Slavcheva, Gabriela, and Alexey V. Kavokin. "Polarization Control of Optically Pumped Terahertz Lasers." MRS Proceedings 1617 (2013): 199–204. http://dx.doi.org/10.1557/opl.2013.1185.

Full text

Abstract:

ABSTRACTTwo-photon pumping of excited exciton states in semiconductor quantum wells is a tool for realization of ultra-compact terahertz (THz) lasers based on stimulated optical transition between excited 2p and ground 1s exciton state. We show that the probability of two-photon absorption by a 2p-exciton is strongly dependent on the polarization of both photons. Variation of the threshold power for THz lasing by a factor of 5 is predicted by switching from linear to circular pumping. We calculate the polarization dependence of the THz emission and identify photon polarization configurations for achieving maximum THz photon generation quantum efficiency.

APA, Harvard, Vancouver, ISO, and other styles

48

Kumano, H., H. Nakajima, S. Ekuni, Y. Idutsu, H. Sasakura, and I. Suemune. "Quantum-Dot-Based Photon Emission and Media Conversion for Quantum Information Applications." Advances in Mathematical Physics 2010 (2010): 1–13. http://dx.doi.org/10.1155/2010/391607.

Full text

Abstract:

Single-photon as well as polarization-correlated photon pair emission from a single semiconductor quantum dots is demonstrated. Single photon generation and single photon-pair generation with little uncorrelated multiphoton emission and the feasibility of media conversion of the quantum states between photon polarization and electron spin are fundamental functions for quantum information applications. Mutual media conversion for the angular momentum between photon polarization and electron spin is also achieved with high fidelity via positively charged exciton state without external magnetic field. This is a clear indication that the coupling of photon polarizations and electron spins keeps secured during whole processes before photon emission. Possibility of a metal-embedded structure is demonstrated with the observation of drastic enhancement of excitation and/or collection efficiency of luminescence as well as clear antibunching of photons generated from a quantum dot.

APA, Harvard, Vancouver, ISO, and other styles

49

Xiu, Xiao-Ming, Li Dong, Ya-Jun Gao, and X. X. Yi. "Nearly deterministic controlled-NOT gate with weak cross-Kerr nonlinearities." Quantum Information and Computation 12, no. 1&2 (January 2012): 159–70. http://dx.doi.org/10.26421/qic12.1-2-11.

Full text

Abstract:

On the basis of the probe coherent state and weak cross-Kerr nonlinearities, we present a scheme of a nearly deterministic Controlled-NOT gate. In this construction, feed-forward methods, quantum nondemolition detectors and several optical elements are applied. It is a potentially practical quantum gate with certain features. First, the lack of auxiliary photons is allowable, which decreases consumption of resources. Secondly, employment of the signal photon from either of target output ports and three quantum nondemolition detectors enable the success probability to approach unit and judge whether the signal photons lose or not. Thirdly, the displacement measurement is adopted, and thus the Controlled-NOT gate works against photon loss of the probe coherent state. Finally, in order to circumvent the effect of dephasing, the monochromatic signal photons are exploited.

APA, Harvard, Vancouver, ISO, and other styles

50

Duc, T. M., T. Q. Dat, and H. S. Chuong. "Quantum entanglement and teleportation in superposition of multiple-photon-added two-mode squeezed vacuum state." International Journal of Modern Physics B 34, no. 25 (September 15, 2020): 2050223. http://dx.doi.org/10.1142/s0217979220502239.

Full text

Abstract:

In this paper, a new state called superposition of multiple-photon-added two-mode squeezed vacuum state (SMPA-TMSVS) is introduced by adding the multiple photons to both modes of a two-mode squeezed vacuum state (TMSVS). We explicitly investigate the degree of quantum entanglement, the Einstein–Podolsky–Rosen (EPR) correlation and the quantum steering in the SMPA-TMSVS. The results show in the SMPA-TMSVS that the degree of entanglement and the EPR correlation can be enhanced by nonlocal adding photons to a TMSVS. The quantum steering appears in the SMPA-TMSVS in case the superposition of single-photon addition [Formula: see text], in which mode [Formula: see text] can steer mode [Formula: see text]. By using the SMPA-TMSVS as an entangled resource, the quantum teleportation process is studied in detail based on the Vaidman–Braunstein–Kimble (VBK) protocol.

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!