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Sample records for dipole induced transparency

  1. Dipole-induced electromagnetic transparency.

    PubMed

    Puthumpally-Joseph, Raiju; Sukharev, Maxim; Atabek, Osman; Charron, Eric

    2014-10-17

    We determine the optical response of a thin and dense layer of interacting quantum emitters. We show that, in such a dense system, the Lorentz redshift and the associated interaction broadening can be used to control the transmission and reflection spectra. In the presence of overlapping resonances, a dipole-induced electromagnetic transparency (DIET) regime, similar to electromagnetically induced transparency (EIT), may be achieved. DIET relies on destructive interference between the electromagnetic waves emitted by quantum emitters. Carefully tuning material parameters allows us to achieve narrow transmission windows in, otherwise, completely opaque media. We analyze in detail this coherent and collective effect using a generalized Lorentz model and show how it can be controlled. Several potential applications of the phenomenon, such as slow light, are proposed.

  2. Deterministic controlled-phase gate and SWAP gate with dipole-induced transparency in the weak-coupling regime

    NASA Astrophysics Data System (ADS)

    Liu, A.-Peng; Cheng, Liu-Yong; Zhang, Shou; Zhao, Yu; Gao, Xiao-Zhen; Chang, Yan-Hong; Wang, Ai-Ping

    2016-11-01

    We present a scheme to construct a controlled phase-flip (CPF) gate deterministically with the dipole induced transparency (DIT) of a diamond nitrogen-vacancy center embedded in a photonic crystal cavity coupled to two waveguides. Further more, a SWAP gate between a photon and an NV center in cavity is presented with the same quantum system by using the CPF gate. We then show a quantum teleportation scheme between two remote NV centers. The fidelities and efficiencies of the gates can reach relatively high values even if cavity decay and leakage are considered.

  3. Direct measurement of excited-state dipole matrix elements using electromagnetically induced transparency in the hyperfine Paschen-Back regime

    NASA Astrophysics Data System (ADS)

    Whiting, Daniel J.; Keaveney, James; Adams, Charles S.; Hughes, Ifan G.

    2016-04-01

    Applying large magnetic fields to gain access to the hyperfine Paschen-Back regime can isolate three-level systems in a hot alkali metal vapors, thereby simplifying usually complex atom-light interactions. We use this method to make the first direct measurement of the |<5 P ||e r ||5 D >| matrix element in 87Rb. An analytic model with only three levels accurately models the experimental electromagnetically induced transparency spectra and extracted Rabi frequencies are used to determine the dipole matrix element. We measure |<5 P3 /2||e r ||5 D5 /2>| =(2.290 ±0 .002stat±0 .04syst) e a0 , which is in excellent agreement with the theoretical calculations of Safronova, Williams, and Clark [Phys. Rev. A 69, 022509 (2004), 10.1103/PhysRevA.69.022509].

  4. Graphene-based optically transparent dipole antenna

    NASA Astrophysics Data System (ADS)

    Kosuga, Shohei; Suga, Ryosuke; Hashimoto, Osamu; Koh, Shinji

    2017-06-01

    We fabricated an optically transparent dipole antenna based on chemical vapor deposition (CVD)-grown monolayer graphene on an optically transparent quartz substrate and characterized its properties in microwave bands. The measurements of the reflection coefficients for the dipole antenna revealed that ˜90% of the microwave power transmitted to the CVD monolayer graphene of the antenna element. By measuring transmission coefficients, we demonstrated that the graphene dipole antenna radiated microwave power around the operational frequency (˜20.7 GHz). The operational frequency of the graphene dipole antenna (˜20.7 GHz) shifted to a higher frequency than that of the Au dipole antenna with the same structure (˜9.2 GHz), which suggests that monolayer graphene behaves not as a metal but as a dielectric material.

  5. Simultaneous use of Cs and Rb Rydberg atoms for dipole moment assessment and RF electric field measurements via electromagnetically induced transparency

    NASA Astrophysics Data System (ADS)

    Simons, Matt T.; Gordon, Joshua A.; Holloway, Christopher L.

    2016-09-01

    We demonstrate simultaneous electromagnetically-induced transparency (EIT) with cesium (Cs) and rubidium (Rb) Rydberg atoms in the same vapor cell with coincident (overlapping) optical fields. Each atomic system can detect radio frequency (RF) electric (E) field strengths through the modification of the EIT signal (Autler-Townes (AT) splitting), which leads to a direct International System of Unit traceable RF E-field measurement. We show that these two systems can detect the same RF E-field strength simultaneously, which provides a direct in situ comparison of Rb and Cs RF measurements in Rydberg atoms. In effect, this allows us to perform two measurements of the same E-field strength, providing a relative comparison of the dipole moments of the two atomic species. This gives two measurements that help rule out systematic effects and uncertainties in this E-field metrology approach, which are important when establishing an international measurement standard for an E-field strength, and is a necessary step for this method to be accepted as a standard calibration technique. We use this approach to measure E-fields at 9.2 GHz, 11.6 GHz, and 13.4 GHz, which correspond to three different atomic states (different principal atomic numbers and angular momentums) for the two atom species.

  6. Retardation effects in induced atomic dipole-dipole interactions

    NASA Astrophysics Data System (ADS)

    Graham, S. D.; McGuirk, J. M.

    2017-02-01

    We present mean-field calculations of azimuthally averaged retarded dipole-dipole interactions in a Bose-Einstein condensate induced by a laser, at both long and short wavelengths. Our calculations demonstrate that dipole-dipole interactions become significantly stronger at shorter wavelengths, by as much as 30-fold, due to retardation effects. This enhancement, along with the inclusion of the dynamic polarizability, indicate a method of inducing long-range interatomic interactions in neutral atom condensates at significantly lower intensities than previously realized.

  7. Efficient treatment of induced dipoles

    PubMed Central

    Simmonett, Andrew C.; Pickard, Frank C.; Shao, Yihan; Cheatham, Thomas E.; Brooks, Bernard R.

    2015-01-01

    Most existing treatments of induced dipoles in polarizable molecular mechanics force field calculations use either the self-consistent variational method, which is solved iteratively, or the “direct” approximation that is non-iterative as a result of neglecting coupling between induced dipoles. The variational method is usually implemented using assumptions that are only strictly valid under tight convergence of the induced dipoles, which can be computationally demanding to enforce. In this work, we discuss the nature of the errors that result from insufficient convergence and suggest a strategy that avoids such problems. Using perturbation theory to reintroduce the mutual coupling into the direct algorithm, we present a computationally efficient method that combines the precision of the direct approach with the accuracy of the variational approach. By analyzing the convergence of this perturbation series, we derive a simple extrapolation formula that delivers a very accurate approximation to the infinite order solution at the cost of only a few iterations. We refer to the new method as extrapolated perturbation theory. Finally, we draw connections to our previously published permanent multipole algorithm to develop an efficient implementation of the electric field and Thole terms and also derive some necessary, but not sufficient, criteria that force field parameters must obey. PMID:26298123

  8. Transparency window for the absorptive dipole resonance in a symmetry-reduced grating structure.

    PubMed

    Dong, Zheng-Gao; Ni, Pei-Gen; Zhu, Jie; Zhang, X

    2012-03-26

    We demonstrate that a transparency window can be obtained within the absorptive dipole resonant regime, by slightly reducing the symmetric arrangement of a dipole-like bar grating covered by a waveguiding layer. The physical understanding is that, under the condition of reducing the grating symmetry, the lossy dipole plasmon resonance can be completely transferred into the waveguide mode in a way of destructive interference. In accompany with the tunable transparency window modulated by the symmetry-reduced displacement, an ultra high group index (slowing down the light) as well as a vortex distribution of the electromagnetic field is found.

  9. Dipolar exchange induced transparency with Rydberg atoms

    NASA Astrophysics Data System (ADS)

    Petrosyan, David

    2017-03-01

    A three-level atomic medium can be made transparent to a resonant probe field in the presence of a strong control field acting on an adjacent atomic transition to a long-lived state, which can be represented by a highly excited Rydberg state. The long-range interactions between the Rydberg state atoms then translate into strong, non-local, dispersive or absorptive interactions between the probe photons, which can be used to achieve deterministic quantum logic gates and single photon sources. Here we show that long-range dipole–dipole exchange interaction with one or more spins—two-level systems represented by atoms in suitable Rydberg states—can play the role of control field for the optically dense medium of atoms. This induces transparency of the medium for a number of probe photons n p not exceeding the number of spins n s , while all the excess photons are resonantly absorbed upon propagation. In the most practical case of a single spin atom prepared in the Rydberg state, the medium is thus transparent only to a single input probe photon. For larger number of spins n s , all n p ≤ n s photon components of the probe field would experience transparency but with an n p -dependent group velocity.

  10. Axion induced oscillating electric dipole moments

    DOE PAGES

    Hill, Christopher T.

    2015-06-24

    In this study, the axion electromagnetic anomaly induces an oscillating electric dipole for any magnetic dipole. This is a low energy theorem which is a consequence of the space-time dependent cosmic background field of the axion. The electron will acquire an oscillating electric dipole of frequency ma and strength ~ 10-32 e-cm, within four orders of magnitude of the present standard model DC limit, and two orders of magnitude above the nucleon, assuming standard axion model and dark matter parameters. This may suggest sensitive new experimental venues for the axion dark matter search.

  11. Axion induced oscillating electric dipole moments

    SciTech Connect

    Hill, Christopher T.

    2015-06-24

    In this study, the axion electromagnetic anomaly induces an oscillating electric dipole for any magnetic dipole. This is a low energy theorem which is a consequence of the space-time dependent cosmic background field of the axion. The electron will acquire an oscillating electric dipole of frequency ma and strength ~ 10-32 e-cm, within four orders of magnitude of the present standard model DC limit, and two orders of magnitude above the nucleon, assuming standard axion model and dark matter parameters. This may suggest sensitive new experimental venues for the axion dark matter search.

  12. Induced dipole-dipole interactions in light diffusion from point dipoles

    NASA Astrophysics Data System (ADS)

    Cherroret, Nicolas; Delande, Dominique; van Tiggelen, Bart A.

    2016-07-01

    We develop a perturbative treatment of induced dipole-dipole interactions in the diffusive transport of electromagnetic waves through disordered atomic clouds. The approach is exact at order 2 in the atomic density and accounts for the vector character of light. It is applied to the calculations of the electromagnetic energy stored in the atomic cloud, which modifies the energy transport velocity, and of the light scattering and transport mean free paths. Results are compared to those obtained from a purely scalar model for light.

  13. Second-order nonlinearity induced transparency.

    PubMed

    Zhou, Y H; Zhang, S S; Shen, H Z; Yi, X X

    2017-04-01

    In analogy to electromagnetically induced transparency, optomechanically induced transparency was proposed recently in [Science330, 1520 (2010)SCIEAS0036-807510.1126/science.1195596]. In this Letter, we demonstrate another form of induced transparency enabled by second-order nonlinearity. A practical application of the second-order nonlinearity induced transparency is to measure the second-order nonlinear coefficient. Our scheme might find applications in quantum optics and quantum information processing.

  14. Broadband cavity electromagnetically induced transparency

    SciTech Connect

    Wei Xiaogang; Wang Yanhua; Zhang Jiepeng; Zhu Yifu

    2011-10-15

    Cavity electromagnetically induced transparency (EIT) is created in a three-level atomic system confined in a cavity and coupled to a free-space control laser and is manifested as a narrow transmission peak of a probe laser coupled into the cavity mode and tuned to the two-photon Raman resonance with the control laser. Cavity EIT can be observed with a control laser detuned from the atomic transition frequency in a range limited by the vacuum Rabi splitting of two cavity-atom normal modes. This leads to the broadband cavity EIT obtained in the coupled-cavity-atom system with a free-space, broadband control laser. We report an experimental observation of broadband cavity EIT in cold Rb atoms with a frequency-modulated control laser and discuss its application in multichannel and multifrequency light memory.

  15. Coupled-Resonator-Induced Transparency

    NASA Technical Reports Server (NTRS)

    Smith, David D.; Chang, Hong-Rok; Fuller, Kirk A.; Rosenberger, A. T.; Boyd, Robert W.

    2003-01-01

    We demonstrate that a cancellation of absorption occurs on resonance for two (or any even number of) coupled optical resonators, due to mode splitting and classical destructive interference, particularly when the resonator finesse is large and the loss in the resonator furthest from the excitation waveguide is small. The linewidth and group velocity of a collection of such coupled-resonator structures may be decreased by using larger resonators of equal size, using larger resonators of unequal size where the optical path length of the larger resonator is an integer multiple of that of the smaller one, or by using a larger number of resonators per structure. We explore the analogy between these effects and electromagnetically induced transparency in an atomic system.

  16. Lines that induce phenomenal transparency.

    PubMed

    Grieco, Alba; Roncato, Sergio

    2005-01-01

    Three neighbouring opaque surfaces may appear split into two layers, one transparent and one opaque beneath, if an outline contour is drawn that encompasses two of them. The phenomenon was originally observed by Kanizsa [1955 Rivista di Psicologia 69 3-19; 1979 Organization in Vision: Essays on Gestalt Psychology (New York: Praeger)], for the case where an outline contour is drawn to encompass one of the two parts of a bicoloured figure and a portion of a background of lightest (or darkest) luminance. Preliminary observations revealed that the outline contour yields different effects: in addition to the stratification into layers described by Kanizsa, a second split, opposite in depth order, may occur when the outline contour is close in luminance to one of the three surfaces. An initial experiment was designed to investigate what conditions give rise to the two phenomenal transparencies: this led to the conclusion that an outline contour superimposed on an opaque surface causes this surface to emerge as a transparent layer when the luminances of the contour and the surface differ, in absolute value, by no more than 13.2 cd m(-2). We have named this phenomenon 'transparency of the intercepted surface', to distinguish it from the phenomenal transparency arising when the contour and surface are very different in luminance. When such a difference exists, the contour acts as a factor of surface definition and grouping: the portion of the homogeneous surface it bounds emerges as a fourth surface and groups with a nearby surface if there is one close in luminance. The transparency phenomena ('transparency of the contoured surface') perceived in this context conform to the constraints of Metelli's model, as demonstrated by a second experiment, designed to gather 'opacity' ratings of stimuli. The observer judgments conformed to the values predicted by Metelli's formula for perceived degree of transparency, alpha. The role of the outline contour in conveying figural and

  17. Dipole-fiber systems: radiation field patterns, effective magnetic dipoles, and induced cavity modes

    NASA Astrophysics Data System (ADS)

    Atakaramians, Shaghik; Miroshnichenko, Andrey E.; Shadrivov, Ilya V.; Monro, Tanya M.; Kivshar, Yuri S.; Afshar, Shahraam V.

    2015-12-01

    We study the radiation patterns produced by a dipole placed at the surface of a nanofiber and oriented perpendicular to it, either along the radial (r-oriented) or azimuthal (Φ-oriented) directions. We find that the dipole induces an effective circular cavity-like leaky mode in the nanofiber. The first radiation peak of the Φ-oriented dipole contributes only to TE radiation modes, while the radiation of the r-oriented dipole is composed of both TE and TM radiation modes, with relative contribution depending on the refractive index of the nanofiber. We reveal that the field pattern of the first resonance of a Φ-oriented dipole is associated with a magnetic dipole mode and strong magnetic response of an optical nanofiber.

  18. Hybrid of Quantum Phases for Induced Dipole Moments

    NASA Astrophysics Data System (ADS)

    Ma, Kai

    2016-09-01

    The quantum phase effects for induced electric and magnetic dipole moments are investigated. It is shown that the phase shift received by induced electric dipole has the same form with the one induced by magnetic dipole moment, therefore the total phase is a hybrid of these two types of phase. This feature indicates that in order to have a decisive measurement on either one of these two phases, it is necessary to measure the velocity dependence of the observed phase.

  19. Induced Transparency and Absorption in Coupled Microresonators

    NASA Technical Reports Server (NTRS)

    Smith, David D.; Chang, Hongrok

    2004-01-01

    We review the conditions for the occurrence of coherence phenomena in passive coupled optical microresonators. We derive the effective steady-state response and determine conditions for induced transparency and absorption in these systems.

  20. Induced Transparency and Absorption in Coupled Microresonators

    NASA Technical Reports Server (NTRS)

    Smith, David D.; Chang, Hongrok

    2004-01-01

    We review the conditions for the occurrence of coherence phenomena in passive coupled optical microresonators. We derive the effective steady-state response and determine conditions for induced transparency and absorption in these systems.

  1. Manipulation of electromagnetically induced transparency by planar metamaterial

    NASA Astrophysics Data System (ADS)

    Yang, Helin; Hu, Sen; Liu, Dan; Lin, Hai; Xiao, Boxun; Chen, Jiao

    2016-02-01

    The transmission characteristics of a planar metamaterial, composed of a metal ring and a regular trigonometry-star-rod (TSR), have been numerically and experimentally investigated in this paper. By rotating the TSR with different angles, this structure will appear to be symmetric or asymmetric toward the incident waves and then finely controls the coupling between the ring and the TSR. Thus, the transmission spectrum of our proposed structure can exhibit an electromagnetically induced transparency (EIT)-like spectral response in microwave region. Owing to the C3 rotational symmetry of the structure, an on-to-off active modulation of the EIT-like transparency window can be realized, and it may serve as the base for a microwave optical switching. Equivalent electric dipole moments couplings are employed to explain the transmission properties. In all, our work provides a way to obtain EIT-like effect, and it may achieve potential applications in filters, sensing and some other microwave devices.

  2. Lunar magnetic field - Permanent and induced dipole moments

    NASA Technical Reports Server (NTRS)

    Russell, C. T.; Coleman, P. J., Jr.; Schubert, G.

    1974-01-01

    Apollo 15 subsatellite magnetic field observations have been used to measure both the permanent and the induced lunar dipole moments. Although only an upper limit of 1.3 x 10 to the 18th gauss-cubic centimeters has been determined for the permanent dipole moment in the orbital plane, there is a significant induced dipole moment which opposes the applied field, indicating the existence of a weak lunar ionosphere.

  3. Optical precursors with self-induced transparency

    SciTech Connect

    Macke, Bruno; Segard, Bernard

    2010-01-15

    Optical Sommerfeld-Brillouin precursors significantly ahead of a main field of comparable amplitude have been recently observed in an opaque medium with an electromagnetically induced transparency window [Wei et al., Phys. Rev. Lett. 103, 093602 (2009)]. We theoretically analyze in this article the somewhat similar results obtained when the transparency is induced by the propagating field itself and we establish an approximate analytic expression of the time delay of the main-field arrival, which fits fairly well the result obtained by numerically solving the Maxwell-Bloch equations.

  4. Induced transparency in optomechanically coupled resonators

    NASA Astrophysics Data System (ADS)

    Duan, Zhenglu; Fan, Bixuan; Stace, Thomas M.; Milburn, G. J.; Holmes, Catherine A.

    2016-02-01

    In this work we theoretically investigate a hybrid system of two optomechanically coupled resonators, which exhibits induced transparency. This is realized by coupling an optical ring resonator to a toroid. In the semiclassical analyses, the system displays bistabilities, isolated branches (isolas), and self-sustained oscillation dynamics. Furthermore, we find that the induced transparency window sensitively relies on the mechanical motion. Based on this fact, we show that the described system can be used as a weak force detector and the optimal sensitivity can beat the standard quantum limit without using feedback control or squeezing under available experimental conditions.

  5. Theory of absorption-induced transparency

    NASA Astrophysics Data System (ADS)

    Rodrigo, Sergio G.; Martín-Moreno, L.

    2014-09-01

    Absorption induced transparency consists in a transmission peak observed in holey metal films when a molecular dye is deposited on top of it [Hutchison et al., Angew. Chem. Int. Ed. 50, 2085 (2011)]. This transmission feature appears unexpectedly close to one of the absorption energies of the molecules, hence its name. Tentative explanations pointed to strong-coupling interactions between plasmons and molecules. However, we recently demonstrated the actual mechanism behind, which takes place through a strong modification of the propagation constant of holes. We also found that absorption induced transparency occurs in single holes and it is not restricted to the optical range.

  6. Electromagnetically induced transparency with quantum interferometry.

    PubMed

    Bhattacharjee, Anindita; Dastidar, Krishna Rai

    2012-02-28

    We have shown that electromagnetically induced transparency can be achieved by control-probe interferometry using two delayed phase-locked ultrashort pulses. Two vibrational wavepackets on the excited state, excited by two delayed phase-locked ultrashort pulses, interfere constructively or destructively leading to enhancement or suppression of absorption to a selective set of vibrational levels. Depending on the phase difference and the delay between the pulses with same carrier frequency, one can design different transparency windows between absorption peaks at consecutive even(odd) vibrational levels by eliminating absorption at odd(even) vibrational levels. We have shown that by switching the phase difference of two delayed femtosecond pulses, one can switch to complete elimination of absorption from enhanced absorption to a particular set of vibrational levels in the excited state. Thus, switching of transparency through window between odd vibrational levels to that between even vibrational levels is possible. By properly choosing the temporal width and the carrier frequency of the pulses, lossless transmission of complete or bands of frequencies of the pulses can be achieved through these transparency windows. Hence, designing of single- or multi-mode transparency windows in NaH molecule is feasible by control-probe quantum interferometry.

  7. Theory of absorption-induced transparency

    NASA Astrophysics Data System (ADS)

    Rodrigo, Sergio G.; García-Vidal, F. J.; Martín-Moreno, L.

    2013-10-01

    Recent experiments [Hutchison, O’Carroll, Schwartz, Genet, and Ebbesen, Angew. Chem. Int. Ed.1433-785110.1002/anie.201006019 50, 2085 (2011)] have demonstrated that optical transmission through an array of subwavelength holes in a metal film can be enhanced by the intentional presence of dyes in the system. As the transmission maximum occurs spectrally close to the absorption resonances of the dyes, this phenomenon was christened “absorption induced transparency”. Here, a theoretical study on absorption induced transparency is presented. The results show that the appearance of transmission maxima requires that the absorbent fills the holes and that it occurs also for single holes. Furthermore, it is shown that the transmission process is nonresonant, being composed by a sequential passage of the electromagnetic field through the hole. Finally, the physical origin of the phenomenon is demonstrated to be nonplasmonic, which implies that absorption induced transparency should also occur at the infrared or terahertz frequency regimes.

  8. Polarization spectra of Zeeman sublevels in Rydberg electromagnetically induced transparency

    NASA Astrophysics Data System (ADS)

    Bao, Shanxia; Zhang, Hao; Zhou, Jian; Zhang, Linjie; Zhao, Jianming; Xiao, Liantuan; Jia, Suotang

    2016-10-01

    The polarization spectra of electromagnetically induced transparency (EIT) for Zeeman sublevels in a cascade system with Rydberg state are demonstrated. The magnitude dependence of Rydberg-EIT on the polarizations of probe and coupling laser fields is studied, and shown mainly due to the strengths of relative dipole matrix elements between degenerate Zeeman sublevels. We further investigate the polarization spectra of Rydberg-EIT in the optimal polarization combinations of left-handed and right-handed circularly polarized fields when an external magnetic field is applied. The existence of nondegenerate Zeeman sublevels in an external magnetic field results in the splitting of Rydberg-EIT. The theoretical calculations are very consistent with the experimental spectra.

  9. Quantum Heat Engine Using Electromagnetically Induced Transparency

    NASA Astrophysics Data System (ADS)

    Zou, Yueyang; Jiang, Yue; Mei, Yefeng; Guo, Xianxin; Du, Shengwang

    2017-08-01

    We report an experiment demonstrating the generation of directional thermal radiation with a spectral brightness that is about 9 times greater than that of the ambient pumping reservoir. The experiment is based on the recent proposal for a nontraditional quantum heat engine and uses cold Rb atoms, electromagnetically induced transparency, and photon correlation spectroscopy [Phys. Rev. A 94, 053859 (2016), 10.1103/PhysRevA.94.053859].

  10. Electromagnetically induced transparency and quantum heat engines

    NASA Astrophysics Data System (ADS)

    Harris, S. E.

    2016-11-01

    We describe how electromagnetically induced transparency may be used to construct a nontraditional near-ideal quantum heat engine as constrained by the second law. The engine is pumped by a thermal reservoir that may be either hotter or colder than that of an exhaust reservoir, and also by a monochromatic laser. As output, it produces a bright narrow emission at line center of an otherwise absorbing transition.

  11. Lattice-induced transparency in planar metamaterials

    NASA Astrophysics Data System (ADS)

    Manjappa, Manukumara; Srivastava, Yogesh Kumar; Singh, Ranjan

    2016-10-01

    Lattice modes are intrinsic to periodic structures and they can be easily tuned and controlled by changing the lattice constant of the structural array. Previous studies have revealed the excitation of sharp absorption resonances due to lattice mode coupling with the plasmonic resonances. Here, we report an experimental observation of a lattice-induced transparency (LIT) by coupling the first-order lattice mode (FOLM) to the structural resonance of a terahertz asymmetric split ring resonator. The observed sharp transparency is a result of the destructive interference between the bright mode and the FOLM assisted dark mode. As the FOLM is swept across the metamaterial resonance, the transparency band undergoes a large change in its bandwidth and resonance position. We propose a three-oscillator model to explain the underlying coupling mechanism in LIT system that shows good agreement with the observed results. Besides controlling the transparency behavior, LIT also shows a huge enhancement in its Q factor and exhibits a high group delay of 28 ps with an enhanced group index of 4.5 ×104 , which could be pivotal in ultrasensitive sensing and slow-light device applications.

  12. Electromagnetically induced transparency in optical microcavities

    NASA Astrophysics Data System (ADS)

    Liu, Yong-Chun; Li, Bei-Bei; Xiao, Yun-Feng

    2017-08-01

    Electromagnetically induced transparency (EIT) is a quantum interference effect arising from different transition pathways of optical fields. Within the transparency window, both absorption and dispersion properties strongly change, which results in extensive applications such as slow light and optical storage. Due to the ultrahigh quality factors, massive production on a chip and convenient all-optical control, optical microcavities provide an ideal platform for realizing EIT. Here we review the principle and recent development of EIT in optical microcavities. We focus on the following three situations. First, for a coupled-cavity system, all-optical EIT appears when the optical modes in different cavities couple to each other. Second, in a single microcavity, all-optical EIT is created when interference happens between two optical modes. Moreover, the mechanical oscillation of the microcavity leads to optomechanically induced transparency. Then the applications of EIT effect in microcavity systems are discussed, including light delay and storage, sensing, and field enhancement. A summary is then given in the final part of the paper.

  13. Theoretical study on electromagnetically induced transparency in molecular aggregate models using quantum Liouville equation method

    SciTech Connect

    Minami, Takuya; Nakano, Masayoshi

    2015-01-22

    Electromagnetically induced transparency (EIT), which is known as an efficient control method of optical absorption property, is investigated using the polarizability spectra and population dynamics obtained by solving the quantum Liouville equation. In order to clarify the intermolecular interaction effect on EIT, we examine several molecular aggregate models composed of three-state monomers with the dipole-dipole coupling. On the basis of the present results, we discuss the applicability of EIT in molecular aggregate systems to a new type of optical switch.

  14. Lift-induced vortex dipole collapse

    NASA Astrophysics Data System (ADS)

    Ravichandran, S.; Dixit, Harish N.; Govindarajan, Rama

    2017-03-01

    Two vortices of opposite sign in two dimensions merely move along parallel lines. We show that even a small buoyancy completely changes this dynamics. When the vortices are of different density from their surroundings, buoyancy produces a lateral drift by Kutta lift. This causes the density patches to merge, and the vortex dipole to collapse. This is followed by a rapid upward (for light vortices) ejection and creation of small-scale structures by baroclinic torque. Our simple analytical equation explains the trajectory of the vortices. We show that these events occur in viscous simulations of many buoyant vortices.

  15. Reply to "Comment on `Axion induced oscillating electric dipole moments'"

    NASA Astrophysics Data System (ADS)

    Hill, Christopher T.

    2017-03-01

    We respond to a paper of Flambaum et al. [Phys. Rev. D 95, 058701 (2017).], claiming there is no effective induced oscillating electric dipole moment, e.g., for the electron, arising from interaction with an oscillating cosmic axion background via the anomaly. The relevant Feynman amplitude, Fig. 1, as computed by Flambaum et al., becomes a total divergence, and vanishes. Contrary to this result, we obtained a nonvanishing amplitude that yields physical electric dipole radiation for an electron (or any magnetic dipole moment) immersed in a cosmic axion field. We argue that Flambaum et al.'s counterclaim is incorrect, and is based upon a misunderstanding of a physics choice vs gauge choice, and an assumption that electric dipoles be defined only by coupling to static (constant in time) electric fields.

  16. Electromagnetically induced transparency with noisy lasers

    SciTech Connect

    Xiao Yanhong; Wang Tun; Baryakhtar, Maria; Jiang Liang; Lukin, Mikhail D.; Van Camp, Mackenzie; Crescimanno, Michael; Hohensee, Michael; Walsworth, Ronald L.; Phillips, David F.; Yelin, Susanne F.

    2009-10-15

    We demonstrate and characterize two coherent phenomena that can mitigate the effects of laser phase noise for electromagnetically induced transparency (EIT): a laser-power-broadening-resistant resonance in the transmitted intensity cross correlation between EIT optical fields, and a resonant suppression of the conversion of laser phase noise to intensity noise when one-photon noise dominates over two-photon-detuning noise. Our experimental observations are in good agreement with both an intuitive physical picture and numerical calculations. The results have wide-ranging applications to spectroscopy, atomic clocks, and magnetometers.

  17. Reply to "Comment on `Axion Induced Oscillating Electric Dipole Moments' "

    SciTech Connect

    Hill, Christopher T.

    2015-10-19

    A recent paper of Flambaum, Roberts and Stadnik, [1], claims there is no induced oscillating electric dipole moment (OEDM), eg, for the electron, arising from the oscillating cosmic axion background via the anomaly. This claim is based upon the assumption that electric dipoles always be defined by their coupling to static (constant in time) electric fields. The relevant Feynman diagram, as computed by [1], then becomes a total divergence, and vanishes in momentum space. However, an OEDM does arise from the anomaly, coupled to time dependent electric fields. It shares the decoupling properties with the anomaly. The full action, in an arbitrary gauge, was computed in [2], [3]. It is nonvanishing with a time dependent outgoing photon, and yields physics, eg, electric dipole radiation of an electron immersed in a cosmic axion field.

  18. Noise filtering via electromagnetically induced transparency

    NASA Astrophysics Data System (ADS)

    Jeong, Taek; Bae, In-Ho; Moon, Han Seb

    2017-01-01

    We report on the intensity-noise reduction of pseudo-thermal light via electromagnetically induced transparency (EIT) in the Λ-type system of the 5S1/2-5P1/2 transition in 87Rb. Noise filtering of the pseudo-thermal probe light was achieved via an EIT filter and measured according to the degree of intensity noise of the pseudo-thermal probe light. Reductions in the intensity and spectral noise of the pseudo-thermal probe light with the EIT filter were observed using the direct intensity fluctuation and heterodyne detection technique, respectively. Comparison of the intensity noise of the pseudo-thermal probe light before and after passing through the EIT filter revealed a significant reduction in the intensity noise.

  19. Identification of dipole disorder in low temperature solution processed oxides: its utility and suppression for transparent high performance solution-processed hybrid electronics.

    PubMed

    Banger, Kulbinder; Warwick, Christopher; Lang, Jiang; Broch, Katharina; Halpert, Jonathan E; Socratous, Josephine; Brown, Adam; Leedham, Timothy; Sirringhaus, Henning

    2016-10-01

    The ability to deposit high-quality inorganic semiconductors and dielectrics from solution at low process temperatures (∼200 °C) has become a very important research focus. During the course of our investigation, we identify the presence of an induced dipole present in solid state solution processed inorganic oxide insulator layers processed at reduced temperature (200-350 °C) from either molecular precursors, or well-dispersed metal oxide nanoparticles. Chemical composition analysis coupled with electrical measurements shows that the dielectric instability occurs due to proton migration via the Grotthuss mechanism inducing a long lived dipole disorder. Thus we established conditions for suppressing this effect to afford "ideal" high-k dielectric layer. Using this methodology, solution processed all inorganic thin film transistors (TFTs) with charge carrier mobilities exceeding 6 cm(2) V(-1) s(-1) operating at low voltage (5 V) have been achieved. In addition, we show the broad utility of the perovskite high-k dielectric when processed with state of the art polymer and single crystal organic semiconductors yielding mobilities of approx. 7 cm(2) V(-1) s(-1) at only 4 V. These transparent devices demonstrate excellent electrical device stability and a threshold voltage shift of only 0.41 V over 14 h, which is comparable, or better than sputtered oxide films.

  20. Broadband plasmon-induced transparency in terahertz metamaterials via constructive interference of electric and magnetic couplings.

    PubMed

    Wan, Mingli; Song, Yueli; Zhang, Liufang; Zhou, Fengqun

    2015-10-19

    Plasmon-induced transparency (PIT) is a result of destructive interference of different plasmonic resonators. Due to the extreme dispersion within the narrow transparency window, PIT metamaterials are utilized to realize slow light and nonlinear effect. However, other applications such as broadband filtering more desire a broad transmission frequency band at the PIT resonance. In this paper, a broadband PIT effect is demonstrated theoretically in a planar terahertz metamaterial, consisting of a U-shaped ring (USR) supporting electric and magnetic dipole modes as the bright resonator and a cut wire pair (CWP) possessing planar electric quadrupole and magnetic dipole modes as the dark resonator. The dark resonant modes of the CWP can be excited simultaneously via near-field by both the electric and magnetic dipole modes of the USR. When the electric as well as magnetic excitation pathways constructively interact with each other, the enhanced near-field coupling between bright and dark resonators gives rise to an ultra-broad transparency window across a frequency range greater than 0.61 THz in the transmittance spectrum.

  1. The permanent and induced magnetic dipole moment of the moon

    NASA Technical Reports Server (NTRS)

    Russell, C. T.; Coleman, P. J., Jr.; Lichtenstein, B. R.; Schubert, G.

    1974-01-01

    Magnetic field observations with the Apollo 15 subsatellite have been used to deduce the components of both the permanent and induced lunar dipole moments in the orbital plane. The present permanent lunar magnetic dipole moment in the orbital plane is less than 1.3 times ten to the eighteenth power gauss-cu cm. Any uniformly magnetized near surface layer is therefore constrained to have a thickness-magnetization product less than 2.5 emu-cm per g. The induced moment opposes the external field, implying the existence of a substantial lunar ionosphere with a permeability between 0.63 and 0.85. Combining this with recent measures of the ratio of the relative field strength at the ALSEP and Explorer 35 magnetometers indicates that the global lunar permeability relative to the plasma in the geomagnetic tail lobes is between 1.008 and 1.03.

  2. Transient birefringence effects in electromagnetically induced transparency

    SciTech Connect

    Parshkov, O M

    2015-11-30

    We report the results of numerical modelling of transient birefringence that arises as a result of electromagnetically induced transparency on degenerate quantum transitions between the states with J = 0, 1 and 2 in the presence of the Doppler broadening of spectral lines. It is shown that in the case of a linearly polarised control field, the effect of transient birefringence leads to a decay of the input circularly polarised probe pulse into separate linearly polarised pulses inside a medium. In the case of a circularly polarised control field, the effect of transient birefringence manifests itself in a decay of the input linearly polarised probe pulse into separate circularly polarised pulses. It is shown that the distance that a probe pulse has to pass in a medium before decaying into subpulses is considerably greater in the first case than in the second. The influence of the input probe pulse power and duration on the process of spatial separation into individual pulses inside a medium is studied. A qualitative analysis of the obtained results is presented. (nonlinear optical phenomena)

  3. An empirical extrapolation scheme for efficient treatment of induced dipoles

    NASA Astrophysics Data System (ADS)

    Simmonett, Andrew C.; Pickard, Frank C.; Ponder, Jay W.; Brooks, Bernard R.

    2016-10-01

    Many cutting edge force fields include polarization, to enhance their accuracy and range of applicability. In this work, we develop efficient strategies for the induced dipole polarization method. By fitting various orders of perturbation theory (PT) dipoles to a diverse training set, we arrive at a family of fully analytic methods — whose nth order is referred to OPTn — that span the full spectrum of polarization methods from the fast zeroth-order approach that neglects mutual dipole coupling, approaching the fully variational approach at high order. Our training set contains many difficult cases where the PT series diverges, and we demonstrate that our OPTn methods still deliver excellent results in these cases. Our tests show that the OPTn methods exhibit rapid convergence towards the exact answer with each increasing PT order. The fourth order OPT4 method, whose costs are commensurate with three iterations of the leading conjugate gradient method, is a particularly promising candidate to be used as a drop-in replacement for existing solvers without further parameterization.

  4. Electromagnetically induced transparency in modulated laser fields

    NASA Astrophysics Data System (ADS)

    Jiao, Yuechun; Yang, Zhiwei; Zhang, Hao; Zhang, Linjie; Raithel, Georg; Zhao, Jianming; Jia, Suotang

    2017-02-01

    We study electromagnetically induced transparency (EIT) in a room-temperature cesium vapor cell using wavelength-modulated probe laser light. In the utilized cascade level scheme, the probe laser drives the lower transition 6S {}1/2(F = 4) → 6P {}3/2 (F’ = 5), while the coupling laser drives the Rydberg transition 6P {}3/2 → 57S {}1/2. The probe laser has a fixed average frequency and is modulated at a frequency of a few kHz, with a variable modulation amplitude in the range of tens of MHz. The probe transmission is measured as a function of the detuning of the coupling laser from the Rydberg resonance. The first-harmonic demodulated EIT signal has two peaks that are, in the case of large modulation amplitude, separated by the peak-to-peak modulation amplitude of the probe laser times a scaling factor {λ }{{p}}/{λ }{{c}}, where {λ }{{p}} and {λ }{{c}} are the probe- and coupling-laser wavelengths. The scaling factor is due to Doppler shifts in the EIT geometry. Second-harmonic demodulated EIT signals, obtained with small modulation amplitudes, yield spectral lines that are much narrower than corresponding lines in the modulation-free EIT spectra. The resultant spectroscopic resolution enhancement is conducive to improved measurements of radio-frequency (RF) fields based on Rydberg-atom EIT, an approach in which the response of Rydberg atoms to RF fields is exploited to characterize RF fields. Here, we employ wavelength modulation spectroscopy to reduce the uncertainty of atom-based frequency and field measurement of an RF field in the VHF radio band.

  5. Gyromagnetically induced transparency of metasurfaces (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Shvets, Gennady B.; Mousavi, Hossein; Khanikaev, Alexander; Allen, Jeffery W.; Allen, Monica

    2015-09-01

    The concept of symmetry pervades modern physics. Through the conservation laws derived from various symmetries, high-level restrictions and selection rules can be derived for a variety of physical systems without any need for detailed investigations of their specific properties. The spatial symmetries of electric charge distribution on the metamaterial's surface determine whether the EM resonance is "bright" (radiatively coupled to) or "dark" (radiatively de-coupled from) the EM continuum. As we demonstrate in this talk, other (non-spatial) symmetries and their breaking can also be crucial to determine the properties of EM resonances and enable their mutual coupling, which in turn can give rise to EM Fano interferences. I will consider a meta-surface formed by a two-dimensional array of double-antenna meta-molecules resting on a gyromagnetic ferrite substrate. In conclusion, I will use simple symmetry considerations to predict and numerically demonstrate two phenomena that occur in meta-surfaces when symmetry of the system is reduced by a gyromagnetic substrate: gyromagnetically induced transparency and nonreciprocal Fano interference. These phenomena hold significant promise for practical applications such as the dynamic control of resonant EM interactions using magnetic fields produced by the external currents, mitigation of co-site interference and improving isolation. Spectral positions, radiative lifetimes and quality factors of Fano resonances can be controlled by the magnitude of the external magnetic field. This class of effects may lead to a new generation of tunable and nonreciprocal Fano resonant systems for various applications where strong field enhancement, tunability and nonreciprocity are simultaneously required.

  6. Comparison of electromagnetically induced transparency between silver, gold, and aluminum metamaterials at visible wavelengths.

    PubMed

    Hokari, Ryohei; Kanamori, Yoshiaki; Hane, Kazuhiro

    2014-02-10

    Electromagnetically induced transparency (EIT)-like effects in silver, gold, and aluminum metamaterials consisting of dipole resonators and quadrupole resonators were demonstrated at visible wavelengths. Optical characteristics of the metamaterials could be controlled by the gap distance between the two resonators. EIT-like effects were observed at wavelengths between 603 and 789 nm, 654 and 834 nm, and 462 and 693 nm for the silver, gold, and aluminum EIT metamaterials, respectively. At wavelengths longer than around 650 nm, the silver metamaterials had better EIT-like features. At wavelengths shorter than around 650 nm, on the other hand, the aluminum metamaterials showed promising EIT-like results.

  7. Large group delay in a microwave metamaterial analogue of electromagnetically induced transparency

    SciTech Connect

    Zhang, Lei; Tassin, Philippe; Koschny, Thomas; Kurter, Cihan; Anlage, Steven M.; Soukoulis, C. M.

    2010-12-13

    We report on our experimental work concerning a planar metamaterial exhibiting classical electromagnetically induced transparency (EIT). Using a structure with two mirrored split-ring resonators as the dark element and a cut wire as the radiative element, we demonstrate that an EIT-like resonance can be achieved without breaking the symmetry of the structure. The mirror symmetry of the metamaterial's structural element results in a selection rule inhibiting magnetic dipole radiation for the dark element, and the increased quality factor leads to low absorption (<10%) and large group index (of the order of 30).

  8. Molecular Dipole Osmosis Based on Induced Charge Electro-Osmosis

    NASA Astrophysics Data System (ADS)

    Sugioka, Hideyuki

    2016-09-01

    We propose a novel mechanism of producing a large nonlinear electrokinetic vortex flow around a nonconductive polar molecule in an electrolyte. That is, a large nonlinear electrokinetic slip velocity is derived by considering a local giant permittivity due to a molecular electric dipole moment with induced-charge electro-osmosis (ICEO). Different from the conventional ICEO theory, our theory predicts that a nonconductive biomaterial, such as a base of a deoxyribonucleic acid (DNA) molecule, has a significantly high ICEO flow velocity because of its large local permittivity. We consider that our findings will contribute markedly to promising biomedical applications.

  9. Electromagnetically induced transparency with amplification in superconducting circuits.

    PubMed

    Joo, Jaewoo; Bourassa, Jérôme; Blais, Alexandre; Sanders, Barry C

    2010-08-13

    We show that controlling relative phases of electromagnetic fields driving an atom with a Δ-configuration energy-level structure enables optical susceptibility to be engineered in novel ways. In particular, relative-phase control can yield electromagnetically induced transparency but with the benefit that the transparency window is sandwiched between an absorption and an amplification band rather than between two absorption bands in typical electromagnetically induced transparency. We show that this new phenomenon is achievable for a microwave field interacting with a fluxonium superconducting circuit.

  10. Plasmon-Induced Resonant Energy Transfer: a coherent dipole-dipole coupling mechanism

    NASA Astrophysics Data System (ADS)

    Bristow, Alan D.; Cushing, Scott K.; Li, Jiangtian; Wu, Nianqiang

    Metal-insulator-semiconductor core-shell nanoparticles have been used to demonstrate a dipole-dipole coupling mechanism that is entirely dependent on the dephasing time of the localized plasmonic resonance. Consequently, the short-time scale of the plasmons leads to broad energy uncertainty that allows for excitation of charge carriers in the semiconductor via stimulation of photons with energies below the energy band gap. In addition, this coherent energy transfer process overcomes interfacial losses often associated with direct charge transfer. This work explores the efficiency of the energy transfer process, the dipole-dipole coupling strength with dipole separation, shell thickness and plasmonic resonance overlap. We demonstrate limits where the coherent nature of the coupling is switched off and charge transfer processes can dominate. Experiments are performed using transient absorption spectroscopy. Results are compared to calculations using a quantum master equation. These nanostructures show strong potential for improving solar light-harvesting for power and fuel generation.

  11. Tailoring the multiple electrically resonant transparency through bi-layered metamaterial-induced coupling oscillators

    NASA Astrophysics Data System (ADS)

    Zhao, Jiaxin; Han, Song; Lin, Hai; Yang, Helin

    2015-11-01

    Metamaterials (MMs) can be tailored to support electromagnetic interference, which is the kernel for the material-based electromagnetically induced transparency (EIT) phenomena, alternatively transparency based on electric interference can be deemed as electrically resonant transparency (ERT). Here, we experimentally and theoretically demonstrate two kinds of bi-layered MMs. The C3-C6 hybrid MM exhibits triple-mode ERT with transmission peaks of 0.84 at 9.6 GHz, 0.92 at 10.4 GHz, and 0.93 at 11.5 GHz for the horizontally polarized wave, and dual-mode ERT with transmission peaks of 0.84 at 8.8 GHz and 0.91 at 10.2 GHz for the vertically polarized wave. However, the C4-C8 hybrid MM, with two stable transparent peaks of 0.92 and 0.88 at 10.46 GHz and 11.61 GHz, is proven to be polarization independent. The measured results show excellent agreement with numerical simulations. A coupled oscillator model is employed to theoretically study the near field interference between the induced dipoles on the transmission properties. The results presented here will find their application value for multi-mode slow light devices, filters and attenuators, and so on.

  12. Tunable phonon-induced transparency in bilayer graphene nanoribbons.

    PubMed

    Yan, Hugen; Low, Tony; Guinea, Francisco; Xia, Fengnian; Avouris, Phaedon

    2014-08-13

    In the phenomenon of plasmon-induced transparency, which is a classical analogue of electromagnetically induced transparency (EIT) in atomic gases, the coherent interference between two plasmon modes results in an optical transparency window in a broad absorption spectrum. With the requirement of contrasting lifetimes, typically one of the plasmon modes involved is a dark mode that has limited coupling to the electromagnetic radiation and possesses relatively longer lifetime. Plasmon-induced transparency not only leads to light transmission at otherwise opaque frequency regions but also results in the slowing of light group velocity and enhanced optical nonlinearity. In this article, we report an analogous behavior, denoted as phonon-induced transparency (PIT), in AB-stacked bilayer graphene nanoribbons. Here, light absorption due to the plasmon excitation is suppressed in a narrow window due to the coupling with the infrared active Γ-point optical phonon, whose function here is similar to that of the dark plasmon mode in the plasmon-induced transparency. We further show that PIT in bilayer graphene is actively tunable by electrostatic gating and estimate a maximum slow light factor of around 500 at the phonon frequency of 1580 cm(-1), based on the measured spectra. Our demonstration opens an avenue for the exploration of few-photon nonlinear optics and slow light in this novel two-dimensional material.

  13. Photon number dependent group velocity in vacuum induced transparency

    NASA Astrophysics Data System (ADS)

    Lauk, Nikolai; Fleischhauer, Michael

    2015-05-01

    Vacuum induced transparency (VIT) is an effect which occurs in an ensemble of three level atoms in a Λ configuration that interact with two quantized fields. Coupling of one transition to a cavity mode induces transparency for the second field on the otherwise opaque transition similar to the well known EIT effect. In the strong coupling regime even an empty cavity leads to transparency, in contrast to EIT where the presence of a strong control field is required. This transparency is accompanied by a reduction of the group velocity for the propagating field. However, unlike in EIT the group velocity in VIT depends on the number of incoming photons, i.e. different photon number components propagate with different velocities. Here we investigate the possibility of using this effect to spatially separate different photon number components of an initially coherent pulse. We present the results of our calculations and discuss a possible experimental realization.

  14. Axion Induced Oscillating Electric Dipole Moment of the Electron

    SciTech Connect

    Hill, Christopher T.

    2016-01-12

    A cosmic axion, via the electromagnetic anomaly, induces an oscillating electric dipole for the electron of frequency ma and strength ~(few) x 10-32 e-cm, two orders of magnitude above the nucleon, and within a few orders of magnitude of the present standard model constant limit. We give a detailed study of this phenomenon via the interaction of the cosmic axion, through the electromagnetic anomaly, with particular emphasis on the decoupling limit of the axion, ∂ta(t) ∝ mα → 0. The analysis is subtle, and we find the general form of the action involves a local contact interaction and a nonlocal contribution, analogous to the “transverse current” in QED, that enforces the decoupling limit. We carefully derive the effective action in the Pauli-Schroedinger non-relativistic formalism, and in Georgi’s heavy quark formalism adapted to the “heavy electron” (me >> ma). We compute the electric dipole radiation emitted by free electrons, magnets and currents, immersed in the cosmic axion field, and discuss experimental configurations that may yield a detectable signal.

  15. Axion Induced Oscillating Electric Dipole Moment of the Electron

    DOE PAGES

    Hill, Christopher T.

    2016-01-12

    A cosmic axion, via the electromagnetic anomaly, induces an oscillating electric dipole for the electron of frequency ma and strength ~(few) x 10-32 e-cm, two orders of magnitude above the nucleon, and within a few orders of magnitude of the present standard model constant limit. We give a detailed study of this phenomenon via the interaction of the cosmic axion, through the electromagnetic anomaly, with particular emphasis on the decoupling limit of the axion, ∂ta(t) ∝ mα → 0. The analysis is subtle, and we find the general form of the action involves a local contact interaction and a nonlocalmore » contribution, analogous to the “transverse current” in QED, that enforces the decoupling limit. We carefully derive the effective action in the Pauli-Schroedinger non-relativistic formalism, and in Georgi’s heavy quark formalism adapted to the “heavy electron” (me >> ma). We compute the electric dipole radiation emitted by free electrons, magnets and currents, immersed in the cosmic axion field, and discuss experimental configurations that may yield a detectable signal.« less

  16. Local modulation of double optomechanically induced transparency and amplification.

    PubMed

    Yang, Q; Hou, B P; Lai, D G

    2017-05-01

    We consider the probe absorption properties in a mechanically coupled optomechanical system in which the two coupled nanomechanical oscillators are driven by the time-dependent forces, respectively. It is found that the mechanical interaction splits the transparency window for a usual single-mode optomechanical system into two parts and then leads to appearance of the double optomechanically induced transparency. The distance between the two transparency positions (the frequency for the maximal transparency) is determined by the mechanical interaction amplitude. This can be explained by using optomechanical dressed-mode picture which is analogue to the interacting dark resonances in coherent atoms. When the mechanical resonators are driven by the external forces, the transparencies in the double-transparency spectrum can be increased into amplifications or be suppressed by tuning the amplitude of the forces. Additionally, it is shown that the double transparencies or the amplifications oscillate with the initial phases of the forces with a period of 2π. These investigations will be useful for more flexible controllability of multi-channel optical communication based on the optomechanical systems.

  17. Triplet absorption spectroscopy and electromagnetically induced transparency

    NASA Astrophysics Data System (ADS)

    Ghafoor, F.; Nazmitdinov, R. G.

    2016-09-01

    Coherence phenomena in a four-level atomic system, cyclically driven by three coherent fields, are investigated thoroughly at zero and weak magnetic fields. Each strongly interacting atomic state is converted to a triplet due to a dynamical Stark effect. Two dark lines with a Fano-like profile arise in the triplet absorption spectrum with anomalous dispersions. We provide conditions to control the widths of the transparency windows by means of the relative phase of the driving fields and the intensity of the microwave field, which closes the optical system loop. The effect of Doppler broadening on the results of the triplet absorption spectroscopy is analysed in detail.

  18. Electromagnetically Induced Transparency from a Single Atom in Free Space

    NASA Astrophysics Data System (ADS)

    Slodička, L.; Hétet, G.; Gerber, S.; Hennrich, M.; Blatt, R.

    2010-10-01

    In this Letter, we report an absorption spectroscopy experiment and the observation of electromagnetically induced transparency from a single trapped atom. We focus a weak and narrow band Gaussian light beam onto an optically cooled Ba+138 ion using a high numerical aperture lens. Extinction of this beam is observed with measured values of up to 1.35%. We demonstrate electromagnetically induced transparency of the ion by tuning a strong control beam over a two-photon resonance in a three-level Λ-type system. The probe beam extinction is inhibited by more than 75% due to population trapping.

  19. Transparency

    ERIC Educational Resources Information Center

    LaFee, Scott

    2009-01-01

    Citizens now expect access to information, particularly from public institutions like local school districts. They demand input and accountability. Cultural and technological changes, such as the Internet, make it possible for districts to comply. Yet transparency--the easily seen and understood actions of a school district and the thinking behind…

  20. Transparency

    ERIC Educational Resources Information Center

    LaFee, Scott

    2009-01-01

    Citizens now expect access to information, particularly from public institutions like local school districts. They demand input and accountability. Cultural and technological changes, such as the Internet, make it possible for districts to comply. Yet transparency--the easily seen and understood actions of a school district and the thinking behind…

  1. Enhanced nonlinear susceptibility via double-double electromagnetically induced transparency

    NASA Astrophysics Data System (ADS)

    Alotaibi, Hessa M. M.; Sanders, Barry C.

    2016-11-01

    We investigate the nonlinear optical susceptibility of an alkali-metal atom with tripod electronic configuration responsible for generating cross-phase modulation and self-phase modulation under the condition of double-double electromagnetically induced transparency. Our investigation demonstrates an enhancement in the nonlinear optical susceptibility of an alkali-metal atom by a factor of 1000 in the region of the second transparency window. This enhancement is in comparison with the atom's susceptibility in the first transparency window for the same parameters under the same conditions. Nonlinear-absorption enhancement arises by canceling Raman-gain generation, which arises when the probe and signal fields have equal intensities. At the center of the second transparency window, we obtain the condition required to attain a nonvanishing nonlinear optical susceptibility. In the bare-state picture, the coupling field must be off resonant from a bare-to-bare-state transition, while working in the semiclassical dressed picture required the signal field to be tuned off resonantly with a bare-to-dressed-state transition. The relation that governs the values of coupling- and signal-field detuning are also obtained. Our scheme exhibits the fact that the second transparency window has advantages over the first transparency window with respect to obtaining an enhanced Kerr effect, and our calculation includes simulation of both low-temperature and Doppler-broadened regimes.

  2. Optomechanically induced transparency and absorption in hybridized optomechanical systems

    NASA Astrophysics Data System (ADS)

    Hou, B. P.; Wei, L. F.; Wang, S. J.

    2015-09-01

    We present the normal-mode splitting and optomechanically induced transparency or absorption phenomena in the strongly tunnel-coupled optomechanical cavities. In the probe output spectrum, there appear central transparency windows or absorption peaks around which two broad sidebands are symmetrically located. It has been confirmed by the quantitative findings that two broad sidebands, which include the distorted absorption peaks, indicate the normal-mode splitting of the two hybridized cavities, and central transparency windows or absorption peaks character the interference induced by the optomechanical interactions. Additionally, the switching from absorption to amplification can be realized by only adjusting the tunnel interaction. These spectrum properties can be used for the coherent control of light pulses via microfabricated optomechanical arrays.

  3. Controllable motion of optical vortex arrays using electromagnetically induced transparency.

    PubMed

    Shwa, David; Shtranvasser, Evgeny; Shalibo, Yoni; Katz, Nadav

    2012-10-22

    We demonstrate control of the collective motion of an optical vortex array using an electromagnetically induced transparency media. Scanning the frequency detuning between the pump and probe fields changes the susceptibility of the media, producing a unique effective diffraction of the vortex array for each detuning. We measure several experimental configurations and compare them to numerical simulations.

  4. On the graphite-induced UV transparency in phosphate glasses

    NASA Astrophysics Data System (ADS)

    Jiménez, José A.

    2016-12-01

    In this Communication, the origin of the graphite-induced UV transparency in phosphate glasses is scrutinized beyond the commonly accepted reduction of metal impurities. A systematic study was carried out by melting phosphate glasses with increasing amounts of graphite powder. Subsequent characterizations were performed by UV/Vis transmission, photoluminescence, 31P nuclear magnetic resonance and x-ray photoelectron spectroscopies. The data points to a structural modification accompanying the enhanced UV transparency. A model accounting for Psbnd Osbnd C bond formation and the generation of reactive oxygen species is proposed in line with the new structural view suggested.

  5. Magnetically coupled electromagnetically induced transparency analogy of dielectric metamaterial

    SciTech Connect

    Zhang, Fuli He, Xuan; Zhao, Qian; Lan, Chuwen; Zhou, Ji; Zhang, Weihong Qiu, Kepeng

    2014-03-31

    In this manuscript, we experimentally demonstrate magnetically coupled electromagnetically induced transparency (EIT) analogy effect inside dielectric metamaterial. In contrast to previous studies employed different metallic topological microstructures to introduce dissipation loss change, barium strontium titanate, and calcium titanate (CaTiO{sub 3}) are chosen as the bright and dark EIT resonators, respectively, due to their different intrinsic dielectric loss. Under incident magnetic field excitation, dielectric metamaterial exhibits an EIT-type transparency window around 8.9 GHz, which is accompanied by abrupt change of transmission phase. Numerical calculations show good agreement with experiment spectra and reveal remarkably increased group index, indicating potential application in slow light.

  6. Polarization and incidence insensitive dielectric electromagnetically induced transparency metamaterial.

    PubMed

    Zhang, Fuli; Zhao, Qian; Zhou, Ji; Wang, Shengxiang

    2013-08-26

    In this manuscript, we demonstrate numerically classical analogy of electromagnetically induced transparency (EIT) with a windmill type metamaterial consisting of two dumbbell dielectric resonator. With proper external excitation, dielectric resonators serve as EIT bright and dark elements via electric and magnetic Mie resonances, respectively. Rigorous numerical analyses reveal that dielectric metamaterial exhibits sharp transparency peak characterized by large group index due to the destructive interference between EIT bright and dark resonators. Furthermore, such EIT transmission behavior keeps stable property with respect to polarization and incidence angles.

  7. Matter-wave solitons supported by field-induced dipole-dipole repulsion with spatially modulated strength

    NASA Astrophysics Data System (ADS)

    Li, Yongyao; Liu, Jingfeng; Pang, Wei; Malomed, Boris A.

    2013-11-01

    We demonstrate the existence of one- and two-dimensional (1D and 2D, respectively) bright solitons in the Bose-Einstein condensate with repulsive dipole-dipole interactions induced by a combination of dc and ac polarizing fields, oriented perpendicular to the plane in which the BEC is trapped, assuming that the strength of the fields grows in the radial (r) direction faster than r3. Stable tightly confined 1D and 2D fundamental solitons, twisted solitons in 1D, and solitary vortices in 2D are found in a numerical form. The fundamental solitons remain robust under the action of an expulsive potential, which is induced by the interaction of the dipoles with the polarizing field. The confinement and scaling properties of the soliton families are explained analytically. The Thomas-Fermi approximation is elaborated for fundamental solitons. The mobility of the fundamental solitons is limited to the central area. Stable 1D even and odd solitons are also found in the setting with a double-well modulation function, along with a regime of Josephson oscillations.

  8. Application of Dipole-dipole, Induced Polarization, and CSAMT Electrical Methods to Detect Evidence of an Underground Nuclear Explosion

    NASA Astrophysics Data System (ADS)

    Sweeney, J. J.; Felske, D.

    2013-12-01

    There is little experience with application of electrical methods that can be applied during the continuation period of an on-site inspection (OSI), one of the verification methods of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). In order add to such experience, we conducted controlled source audiomagnetotelluric (CSAMT), dipole-dipole resistivity, and induced polarization electrical measurements along three survey lines over and near to ground zero of an historic nuclear explosion. The presentation will provide details and results of the surveys, an assessment of application of the method toward the purposes of an OSI, and an assessment of the manpower and time requirements for data collection and processing that will impact OSI inspection team operations. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  9. Dipole-dipole interaction in a quantum dot and metallic nanorod hybrid system

    NASA Astrophysics Data System (ADS)

    Singh, Mahi R.; Schindel, Daniel G.; Hatef, Ali

    2011-10-01

    We have studied quantum coherence and interference phenomena in a quantum dot (QD)-metallic nanorod (MNR) hybrid system. Probe and control laser fields are applied to the hybrid system. Induced dipole moments are created in the QD and the MNR, and they interact with each other via the dipole-dipole interaction. Using the density matrix method, it was found that the power spectrum of MNR has two transparent, states and they can be switched to one transparent state by the control field. Ultrafast switching and sensing nanodevices could be produced using this model.

  10. Optical quantum memory based on electromagnetically induced transparency

    NASA Astrophysics Data System (ADS)

    Ma, Lijun; Slattery, Oliver; Tang, Xiao

    2017-04-01

    Electromagnetically induced transparency (EIT) is a promising approach to implement quantum memory in quantum communication and quantum computing applications. In this paper, following a brief overview of the main approaches to quantum memory, we provide details of the physical principle and theory of quantum memory based specifically on EIT. We discuss the key technologies for implementing quantum memory based on EIT and review important milestones, from the first experimental demonstration to current applications in quantum information systems.

  11. Explicitly covariant dispersion relations and self-induced transparency

    NASA Astrophysics Data System (ADS)

    Mahajan, S. M.; Asenjo, Felipe A.

    2017-02-01

    Explicitly covariant dispersion relations for a variety of plasma waves in unmagnetized and magnetized plasmas are derived in a systematic manner from a fully covariant plasma formulation. One needs to invoke relatively little known invariant combinations constructed from the ambient electromagnetic fields and the wave vector to accomplish the program. The implication of this work applied to the self-induced transparency effect is discussed. Some problems arising from the inconsistent use of relativity are pointed out.

  12. Coherent population trapping (CPT) versus electromagnetically induced transparency (EIT)

    NASA Astrophysics Data System (ADS)

    Khan, Sumanta; Kumar, Molahalli Panidhara; Bharti, Vineet; Natarajan, Vasant

    2017-02-01

    We discuss the differences between two well-studied and related phenomena - coherent population trapping (CPT) and electromagnetically induced transparency (EIT). Many differences between the two - such as the effect of power in the beams, detuning of the beams from resonance, and the use of vapor cells filled with buffer gas - are demonstrated experimentally. The experiments are done using magnetic sublevels of the 1 → 1 transition in the D2 line of 87Rb.

  13. Optical quantum memory based on electromagnetically induced transparency.

    PubMed

    Ma, Lijun; Slattery, Oliver; Tang, Xiao

    2017-04-01

    Electromagnetically induced transparency (EIT) is a promising approach to implement quantum memory in quantum communication and quantum computing applications. In this paper, following a brief overview of the main approaches to quantum memory, we provide details of the physical principle and theory of quantum memory based specifically on EIT. We discuss the key technologies for implementing quantum memory based on EIT and review important milestones, from the first experimental demonstration to current applications in quantum information systems.

  14. Enhanced tunability of plasmon induced transparency in graphene strips

    SciTech Connect

    Shi, Xi; Su, Xiaopeng; Yang, Yaping

    2015-04-14

    The approach of slow-light efficiency manipulation is theoretically investigated in graphene analogue of electromagnetically induced transparency (EIT) system, which cannot be realized in conventional quantum regime. In this system, two graphene strips with different Fermi energies placed side by side as radiative elements have been discussed, and the coupling strength between radiative elements and dark elements is tuned by these radiative elements. Our proposed scheme exploits the tuning of coupling strength between the radiative elements and dark elements in contrast with the existing approaches that rely on tuning the damping rates of radiative or dark elements. The transparent window and group delays can be tuned by different coupling strength without changing the geometry of structure. This manipulation can be explained using a temporal coupled-mode theory. Furthermore, the hybridized states in this EIT-like system can be manipulated by tuning the Fermi energy of radiative elements. This kind of controllable electromagnetically induced transparency has many significant potential applications in optoelectronic, photodetectors, tunable sensors, and storage of optical data regimes.

  15. Optomechanically induced transparency associated with steady-state entanglement

    NASA Astrophysics Data System (ADS)

    He, Yong

    2015-01-01

    We theoretically investigate a two-cavity optomechanical system in which a cavity (cavity a ) couples to a mechanical resonator via radiation pressure and to another cavity (cavity c ) via a common waveguide. In the excitation of a strong pump filed to cavity a , the steady-state entanglement between cavity a and c , as a quantum channel, can be generated, which provides an indirect optical pathway to excite cavity c by means of the pump filed. Quantum interference between the direct and indirect optical pathways gives rise to an optomechanically induced transparency appearing in the probe transmission of cavity c . Unlike in a typical optomechanically induced transparency effect, the electromagnetical control of the transmission is implemented by resorting to the quantum channel. Furthermore, the coupling strength of the two cavities is an important factor of the quantum channel, which can influence the width of the transparency window and the bistable behavior of the mean photon number in cavity a . We also illustrate that the electromagnetical control via quantum channel can be exploited to implement the optical switch and the slow light.

  16. Observation of optically induced transparency in a micro-cavity

    NASA Astrophysics Data System (ADS)

    Zheng, Yuanlin; Cao, Jianjun; Wan, Wenjie

    2016-03-01

    We report on the observation of optically induced transparency (OIT) in a compact microresonator in an ambient environment by introducing a four-wave mixing gain to nonlinearly couple two separated resonances of the micro-cavity. Its optical-controlling capacity and non-reciprocity characteristics at the transparency windows are also demonstrated. Active-controlling of the OIT can be achieved by varying a strong pump beam, while a small frequency-detuning of the pump can lead to a Fano-like asymmetric resonance justifying the interference nature of OIT. Furthermore, OIT observed here is a non-reciprocal one, since FWM gain is a unidirectional one owing to the conservation law of momentum.

  17. Dynamically tunable plasmon induced transparency in graphene metamaterials

    NASA Astrophysics Data System (ADS)

    Fu, Guang-Lai; Zhai, Xiang; Li, Hong-Ju; Xia, Sheng-Xuan; Wang, Ling-Ling

    2017-01-01

    Plasmon induced transparency (PIT) with graphene metamaterials is investigated with the finite-difference time-domain method. Interestingly, the modulation of the PIT transparency window can be achieved by changing not only the gap distance between the two resonators but also the polarization angle of the excitation light. The three-level plasmonic system is employed to clearly explain the formation mechanism of the PIT effect. The analytical results show good consistency with the numerical calculations. Moreover, the PIT resonant wavelength and group delays of incident waves can be dynamically tuned by varying the Fermi energy of the graphene. Our designed graphene nanostructure is promising for the development of compact elements such as tunable sensors, switches and slow-light devices.

  18. Driven assembly with multiaxial fields: Creating a soft mode in assemblies of anisometric induced dipoles

    DOE PAGES

    Martin, James E.; Swol, Frank Van

    2015-07-10

    We show that multiaxial fields can induce time-averaged, noncentrosymmetric interactions between particles having polarization anisotropy, yet the multiaxial field itself does not exert either a force or a torque on an isolated particle. These induced interactions lead to particle assemblies whose energy is strongly dependent on both the translational and orientational degrees of freedom of the system. The situation is similar to a collection of permanent dipoles, but the symmetry of the time-averaged interaction is quite distinct, and the scale of the system energy can be dynamically controlled by the magnitude of the applied multiaxial field. In our paper, themore » case of polarizable rods is considered in detail, and it is suggested that collections of rods embedded in spheres can be used to create a material with a dynamically tunable magnetic permeability or dielectric permittivity. We report on Monte Carlo simulations performed to investigate the behavior of assemblies of both multiaxial-field induced dipoles and permanent dipoles arranged onto two-dimensional lattices. Lastly, the ground state of the induced dipoles is an orientational soft mode of aligned dipoles, whereas that of the permanent dipoles is a vortex state.« less

  19. Driven assembly with multiaxial fields: Creating a soft mode in assemblies of anisometric induced dipoles

    SciTech Connect

    Martin, James E.; Swol, Frank Van

    2015-07-10

    We show that multiaxial fields can induce time-averaged, noncentrosymmetric interactions between particles having polarization anisotropy, yet the multiaxial field itself does not exert either a force or a torque on an isolated particle. These induced interactions lead to particle assemblies whose energy is strongly dependent on both the translational and orientational degrees of freedom of the system. The situation is similar to a collection of permanent dipoles, but the symmetry of the time-averaged interaction is quite distinct, and the scale of the system energy can be dynamically controlled by the magnitude of the applied multiaxial field. In our paper, the case of polarizable rods is considered in detail, and it is suggested that collections of rods embedded in spheres can be used to create a material with a dynamically tunable magnetic permeability or dielectric permittivity. We report on Monte Carlo simulations performed to investigate the behavior of assemblies of both multiaxial-field induced dipoles and permanent dipoles arranged onto two-dimensional lattices. Lastly, the ground state of the induced dipoles is an orientational soft mode of aligned dipoles, whereas that of the permanent dipoles is a vortex state.

  20. Group velocity slowdown using phonon-induced transparencies in a quantum dot molecule

    NASA Astrophysics Data System (ADS)

    Jacobs, Andrew; Jennings, Cameron; Kerfoot, Mark; Scheibner, Michael

    2014-03-01

    In a recent study we have demonstrated coherent, non-dissipative behavior of phonons due to optical excitation, which is revealed via optical transparency. Using a single external driving field, the absorption of the molecule demonstrates a marked reduction as a Fano-type resonance of a spatially indirect exciton and direct polaron form a molecular polaron state. The phonon coherence contrasts the typical role of these particles as a channel for non-radiative state decay or pure state dephasing. The optical response of the system is indicative of a coherent phenomenon, similar to electromagnetically induced transparency. Here we investigate theoretically how this phonon coherence affects the optical response of a 3-level V-type system in a tunnel-coupled quantum dot molecule. From the properties of the molecular polaron, we are able to determine the slowdown factor of the driving field group velocity, as well as the dependence of the slowdown on system parameters such as polaron and exciton lifetimes, tunneling strength, and transition dipole moments. The presence of slow light suggests this system is suitable for use in quantum computational components such as optical storage or qubit logic gates.

  1. Induced dipole in vanadium-doped zinc oxide nanosheets and its effects on photoelectrochemical water splitting.

    PubMed

    Lee, Song Mi; Shin, Sung-Ho; Nah, Junghyo; Lee, Min Hyung

    2017-09-27

    Appropriate control of energy band bending at the interface between semiconductors and electrolytes are closely related to performance of photoelectrochemical (PEC) water splitting. Dipoles formed near the surface of semiconductors induces energy band bending at the interface. Energy band bending control has been demonstrated by employing charged molecules and piezoelectric materials. However, chemical and piezoelectric approaches have demerit of chemical instability and inducement of instantaneous dipole, respectively. To overcome these problems, we adopted the ferroelectric material for PEC water splitting, where spontaneous dipoles in the material can be oriented by applying external electric field. In this work, we hydrothermally synthesized vanadium (V)-doped ferroelectric ZnO nanosheets and employed to systematically investigate the dipole effect on performance of V-doped ZnO PEC for water oxidation. Consequently, positively polarized V-doped ZnO photoanode exhibits 125% enhanced water splitting efficiency compared to negatively polarized ones due to favorable band bending for carrier transport from semiconductor to water.

  2. Induced dipole in vanadium-doped zinc oxide nanosheets and its effects on photoelectrochemical water splitting

    NASA Astrophysics Data System (ADS)

    Lee, Song Mi; Shin, Sung-Ho; Nah, Junghyo; Lee, Min Hyung

    2017-09-01

    Appropriate control of energy band bending at the interface between semiconductors and electrolytes are closely related to performance of photoelectrochemical (PEC) water splitting. Dipoles formed near the surface of semiconductors induces energy band bending at the interface. Energy band bending control has been demonstrated by employing charged molecules and piezoelectric materials. However, chemical and piezoelectric approaches have demerit of chemical instability and inducement of instantaneous dipole, respectively. To overcome these problems, we adopted the ferroelectric material for PEC water splitting, where spontaneous dipoles in the material can be oriented by applying external electric field. In this work, we hydrothermally synthesized vanadium (V)-doped ferroelectric ZnO nanosheets and employed to systematically investigate the dipole effect on performance of V-doped ZnO PEC for water oxidation. Consequently, positively polarized V-doped ZnO photoanode exhibits 125% enhanced water splitting efficiency compared to negatively polarized ones due to favorable band bending for carrier transport from semiconductor to water.

  3. Capillary-induced giant elastic dipoles in thin nematic films

    PubMed Central

    Jeridi, Haifa; Gharbi, Mohamed A.; Othman, Tahar; Blanc, Christophe

    2015-01-01

    Directed and true self-assembly mechanisms in nematic liquid crystal colloids rely on specific interactions between microparticles and the topological defects of the matrix. Most ordered structures formed in thin nematic cells are thus based on elastic multipoles consisting of a particle and nearby defects. Here, we report, for the first time to our knowledge, the existence of giant elastic dipoles arising from particles dispersed in free nematic liquid crystal films. We discuss the role of capillarity and film thickness on the dimensions of the dipoles and explain their main features with a simple 2D model. Coupling of capillarity with nematic elasticity could offer ways to tune finely the spatial organization of complex colloidal systems. PMID:26554001

  4. Transparent conducting oxide induced by liquid electrolyte gating

    PubMed Central

    ViolBarbosa, Carlos; Karel, Julie; Kiss, Janos; Gordan, Ovidiu-dorin; Altendorf, Simone G.; Utsumi, Yuki; Samant, Mahesh G.; Wu, Yu-Han; Tsuei, Ku-Ding; Felser, Claudia; Parkin, Stuart S. P.

    2016-01-01

    Optically transparent conducting materials are essential in modern technology. These materials are used as electrodes in displays, photovoltaic cells, and touchscreens; they are also used in energy-conserving windows to reflect the infrared spectrum. The most ubiquitous transparent conducting material is tin-doped indium oxide (ITO), a wide-gap oxide whose conductivity is ascribed to n-type chemical doping. Recently, it has been shown that ionic liquid gating can induce a reversible, nonvolatile metallic phase in initially insulating films of WO3. Here, we use hard X-ray photoelectron spectroscopy and spectroscopic ellipsometry to show that the metallic phase produced by the electrolyte gating does not result from a significant change in the bandgap but rather originates from new in-gap states. These states produce strong absorption below ∼1 eV, outside the visible spectrum, consistent with the formation of a narrow electronic conduction band. Thus WO3 is metallic but remains colorless, unlike other methods to realize tunable electrical conductivity in this material. Core-level photoemission spectra show that the gating reversibly modifies the atomic coordination of W and O atoms without a substantial change of the stoichiometry; we propose a simple model relating these structural changes to the modifications in the electronic structure. Thus we show that ionic liquid gating can tune the conductivity over orders of magnitude while maintaining transparency in the visible range, suggesting the use of ionic liquid gating for many applications. PMID:27647884

  5. Transparent conducting oxide induced by liquid electrolyte gating.

    PubMed

    ViolBarbosa, Carlos; Karel, Julie; Kiss, Janos; Gordan, Ovidiu-Dorin; Altendorf, Simone G; Utsumi, Yuki; Samant, Mahesh G; Wu, Yu-Han; Tsuei, Ku-Ding; Felser, Claudia; Parkin, Stuart S P

    2016-10-04

    Optically transparent conducting materials are essential in modern technology. These materials are used as electrodes in displays, photovoltaic cells, and touchscreens; they are also used in energy-conserving windows to reflect the infrared spectrum. The most ubiquitous transparent conducting material is tin-doped indium oxide (ITO), a wide-gap oxide whose conductivity is ascribed to n-type chemical doping. Recently, it has been shown that ionic liquid gating can induce a reversible, nonvolatile metallic phase in initially insulating films of WO3 Here, we use hard X-ray photoelectron spectroscopy and spectroscopic ellipsometry to show that the metallic phase produced by the electrolyte gating does not result from a significant change in the bandgap but rather originates from new in-gap states. These states produce strong absorption below ∼1 eV, outside the visible spectrum, consistent with the formation of a narrow electronic conduction band. Thus WO3 is metallic but remains colorless, unlike other methods to realize tunable electrical conductivity in this material. Core-level photoemission spectra show that the gating reversibly modifies the atomic coordination of W and O atoms without a substantial change of the stoichiometry; we propose a simple model relating these structural changes to the modifications in the electronic structure. Thus we show that ionic liquid gating can tune the conductivity over orders of magnitude while maintaining transparency in the visible range, suggesting the use of ionic liquid gating for many applications.

  6. Transparent conducting oxide induced by liquid electrolyte gating

    NASA Astrophysics Data System (ADS)

    ViolBarbosa, Carlos; Karel, Julie; Kiss, Janos; Gordan, Ovidiu-dorin; Altendorf, Simone G.; Utsumi, Yuki; Samant, Mahesh G.; Wu, Yu-Han; Tsuei, Ku-Ding; Felser, Claudia; Parkin, Stuart S. P.

    2016-10-01

    Optically transparent conducting materials are essential in modern technology. These materials are used as electrodes in displays, photovoltaic cells, and touchscreens; they are also used in energy-conserving windows to reflect the infrared spectrum. The most ubiquitous transparent conducting material is tin-doped indium oxide (ITO), a wide-gap oxide whose conductivity is ascribed to n-type chemical doping. Recently, it has been shown that ionic liquid gating can induce a reversible, nonvolatile metallic phase in initially insulating films of WO3. Here, we use hard X-ray photoelectron spectroscopy and spectroscopic ellipsometry to show that the metallic phase produced by the electrolyte gating does not result from a significant change in the bandgap but rather originates from new in-gap states. These states produce strong absorption below ˜1 eV, outside the visible spectrum, consistent with the formation of a narrow electronic conduction band. Thus WO3 is metallic but remains colorless, unlike other methods to realize tunable electrical conductivity in this material. Core-level photoemission spectra show that the gating reversibly modifies the atomic coordination of W and O atoms without a substantial change of the stoichiometry; we propose a simple model relating these structural changes to the modifications in the electronic structure. Thus we show that ionic liquid gating can tune the conductivity over orders of magnitude while maintaining transparency in the visible range, suggesting the use of ionic liquid gating for many applications.

  7. Controllable optomechanically induced transparency in coupled optomechanical systems

    NASA Astrophysics Data System (ADS)

    Sohail, Amjad; Zhang, Yang; Usman, Muhammad; Yu, Chang-shui

    2017-04-01

    We have analytically investigated the optomechanically induced transparency (OMIT) in two coupled optomechanical systems. We report that, the presence of two optomechanical couplings and one mechanical coupling between the two resonators, leads to different quantum interference paths and, generates single, double and triple-OMIT windows in the probe absorption spectrum. In particular, we have shown how the OMIT windows are affected by the system parameters, how to control the widths of the OMIT windows and how to control the transitions between the different OMIT windows.

  8. Reconfigurable optical routers based on Coupled Resonator Induced Transparency resonances.

    PubMed

    Mancinelli, M; Bettotti, P; Fedeli, J M; Pavesi, L

    2012-10-08

    The interferometric coupling of pairs of resonators in a resonator sequence generates coupled ring induced transparency (CRIT) resonances. These have quality factors an order of magnitude greater than those of single resonators. We show that it is possible to engineer CRIT resonances in tapered SCISSOR (Side Coupled Integrated Space Sequence of Resonator) to realize fast and efficient reconfigurable optical switches and routers handling several channels while keeping single channel addressing capabilities. Tapered SCISSORs are fabricated in silicon-on-insulator technology. Furthermore, tapered SCISSORs show multiple-channel switching behavior that can be exploited in DWDM applications.

  9. Planar designs for electromagnetically induced transparency in metamaterials.

    PubMed

    Tassin, Philippe; Zhang, Lei; Koschny, Thomas; Economou, E N; Soukoulis, C M

    2009-03-30

    We present a planar design of a metamaterial exhibiting electromagnetically induced transparency that is amenable to experimental verification in the microwave frequency band. The design is based on the coupling of a split-ring resonator with a cut-wire in the same plane. We investigate the sensitivity of the parameters of the transmission window on the coupling strength and on the circuit elements of the individual resonators, and we interpret the results in terms of two linearly coupled Lorentzian resonators. Our metamaterial designs combine low losses with the extremely small group velocity associated with the resonant response in the transmission window, rendering them suitable for slow light applications at room temperature.

  10. Ultra-high sensitive and high resolution optical coherence tomography using a laser induced electromagnetic dipole

    NASA Astrophysics Data System (ADS)

    Kuroda, Hiroto; Baba, Motoyoshi; Suzuki, Masayuki; Yoneya, Shin

    2013-09-01

    Utilizing an optical coherence tomography measurement, we have developed a technique that actively uses a dielectric response due to an induced dipole moment caused by a mode-locked pulsed laser light source. Irradiated laser light in the material induces a photo-induced electric dipole resulting in a refractive index change for its strong electric field. Using this technique, we obtained a highly sensitive fundus retina tomogram of a human eye in vivo with a resolution of 1.3 μm by single scanning for 20 ms using 8 fs mode-locked pulse laser light with a 350 nm spread spectrum.

  11. Beam induced electron cloud resonances in dipole magnetic fields

    NASA Astrophysics Data System (ADS)

    Calvey, J. R.; Hartung, W.; Makita, J.; Venturini, M.

    2016-07-01

    The buildup of low energy electrons in an accelerator, known as electron cloud, can be severely detrimental to machine performance. Under certain beam conditions, the beam can become resonant with the cloud dynamics, accelerating the buildup of electrons. This paper will examine two such effects: multipacting resonances, in which the cloud development time is resonant with the bunch spacing, and cyclotron resonances, in which the cyclotron period of electrons in a magnetic field is a multiple of bunch spacing. Both resonances have been studied directly in dipole fields using retarding field analyzers installed in the Cornell Electron Storage Ring. These measurements are supported by both analytical models and computer simulations.

  12. Molecules with an induced dipole moment in a stochastic electric field.

    PubMed

    Band, Y B; Ben-Shimol, Y

    2013-10-01

    The mean-field dynamics of a molecule with an induced dipole moment (e.g., a homonuclear diatomic molecule) in a deterministic and a stochastic (fluctuating) electric field is solved to obtain the decoherence properties of the system. The average (over fluctuations) electric dipole moment and average angular momentum as a function of time for a Gaussian white noise electric field are determined via perturbative and nonperturbative solutions in the fluctuating field. In the perturbative solution, the components of the average electric dipole moment and the average angular momentum along the deterministic electric field direction do not decay to zero, despite fluctuations in all three components of the electric field. This is in contrast to the decay of the average over fluctuations of a magnetic moment in a Gaussian white noise magnetic field. In the nonperturbative solution, the component of the average electric dipole moment and the average angular momentum in the deterministic electric field direction also decay to zero.

  13. Triple optomechanical induced transparency in a two-cavity system

    NASA Astrophysics Data System (ADS)

    Shi-Chao, Wu; Li-Guo, Qin; Jun, Jing; Guo-Hong, Yang; Zhong-Yang, Wang

    2016-05-01

    We theoretically investigate the optomechanical induced transparency (OMIT) phenomenon in a two-cavity system which is composed of two optomechanical cavities. Both of the cavities consist of a fixed mirror and a high-Q mechanical resonator, and they couple to each other via a common waveguide. We show that in the presence of a strong pump field applied to one cavity and a weak probe field applied to the other, a triple-OMIT can be observed in the output field at the probe frequency. The two mechanical resonators in the two cavities are identical, but they lead to different quantum interference pathways. The transparency windows are induced by the coupling of the two cavities and the optical pressure radiated to the mechanical resonators, which can be controlled via the power of the pump field and the coupling strength of the two cavities. Project supported by the Strategic Priority Research Program, China (Grant No. XDB01010200), the Hundred Talents Program of the Chinese Academy of Sciences (Grant No. Y321311401), and the National Natural Sciences Foundation of China (Grant Nos. 11347147 and 1547035).

  14. Ionic vibration induced transparency and Autler–Townes splitting

    NASA Astrophysics Data System (ADS)

    Shao, Wenjun; Wang, Fei; Feng, Xun-Li; Oh, C. H.

    2017-04-01

    In this work, the absorption spectrum of a two-level ion in a linear Paul trap is investigated, the ion is supposed to be driven by two orthogonal laser beams, the one along the axial of the trap acts as the control light beam, the other as probe beam. When the frequency of the control laser is tuned to the first red sideband of the ionic transition, the coupling between the internal states of the ion and vibrational mode turns out to be a Jaynes–Cummings (JC) Hamiltonian, which together with the coupling between the probe beam and the two-level ion constructs a Λ -type three-level structure. In this case the transparency window may appear in the absorption spectrum of the probe light, which is induced by the ionic vibration and is very similar to the cavity induced transparency (Rice and Brecha 1996 Opt. Commun. 126 230–5). On the other hand, when the frequency of the control laser is tuned to the first blue sideband of the ionic transition, the two-level ion and vibrational mode are governed by an anti-Jaynes–Cummings (anti-JC) Hamiltonian, the total system including the probe beam forms a V-type three-level structure. And the Autler–Townes splitting in the absorption spectrum is found.

  15. Parity-time-symmetry enhanced optomechanically-induced-transparency

    PubMed Central

    Li, Wenlin; Jiang, Yunfeng; Li, Chong; Song, Heshan

    2016-01-01

    We propose and analyze a scheme to enhance optomechanically-induced-transparency (OMIT) based on parity-time-symmetric optomechanical system. Our results predict that an OMIT window which does not exist originally can appear in weak optomechanical coupling and driving system via coupling an auxiliary active cavity with optical gain. This phenomenon is quite different from these reported in previous works in which the gain is considered just to damage OMIT phenomenon even leads to electromagnetically induced absorption or inverted-OMIT. Such enhanced OMIT effects are ascribed to the additional gain which can increase photon number in cavity without reducing effective decay. We also discuss the scheme feasibility by analyzing recent experiment parameters. Our work provide a promising platform for the coherent manipulation and slow light operation, which has potential applications for quantum information processing and quantum optical device. PMID:27489193

  16. Ultrafast fluorescent decay induced by metal-mediated dipole-dipole interaction in two-dimensional molecular aggregates.

    PubMed

    Hu, Qing; Jin, Dafei; Xiao, Jun; Nam, Sang Hoon; Liu, Xiaoze; Liu, Yongmin; Zhang, Xiang; Fang, Nicholas X

    2017-09-19

    Two-dimensional molecular aggregate (2DMA), a thin sheet of strongly interacting dipole molecules self-assembled at close distance on an ordered lattice, is a fascinating fluorescent material. It is distinctively different from the conventional (single or colloidal) dye molecules and quantum dots. In this paper, we verify that when a 2DMA is placed at a nanometric distance from a metallic substrate, the strong and coherent interaction between the dipoles inside the 2DMA dominates its fluorescent decay at a picosecond timescale. Our streak-camera lifetime measurement and interacting lattice-dipole calculation reveal that the metal-mediated dipole-dipole interaction shortens the fluorescent lifetime to about one-half and increases the energy dissipation rate by 10 times that expected from the noninteracting single-dipole picture. Our finding can enrich our understanding of nanoscale energy transfer in molecular excitonic systems and may designate a unique direction for developing fast and efficient optoelectronic devices.

  17. Thermal annealing-induced electric dipole relaxation in natural alexandrite

    NASA Astrophysics Data System (ADS)

    Scalvi, Rosa M. Fernandes; Li, Maximo Siu; Scalvi, Luis V. A.

    2005-02-01

    Electrical properties of natural alexandrite (BeAl2O4:Cr3+) are investigated by the thermally stimulated depolarization current (TSDC) technique. Samples are submitted to consecutive annealing processes and TSDC is carried out after each annealing, yielding bands with different parameters. These bands are fitted by a continuous distribution of relaxation parameters: activation energy and pre-exponential factor of the Arrhenius equation. It has been observed that annealing influences the dipole relaxation behavior, since it promotes a modification of Fe3+ and Cr3+ impurity distributions on sites of distinct symmetry: Al1 and Al2. In order to have a reference for comparison, TSDC is also carried out on a synthetic alexandrite sample, where the only impurity present is Cr3+ ion.

  18. QED vacuum fluctuations and induced electric dipole moment of the neutron

    SciTech Connect

    Dominguez, C. A.; Falomir, H.; Ipinza, M.; Loewe, M.; Kohler, S.; Rojas, J. C.

    2009-08-01

    Quantum fluctuations in the QED vacuum generate nonlinear effects, such as peculiar induced electromagnetic fields. In particular, we show here that an electrically neutral particle, possessing a magnetic dipole moment, develops an induced electric dipole-type moment with unusual angular dependence, when immersed in a quasistatic, constant external electric field. The calculation of this effect is done in the framework of the Euler-Heisenberg effective QED Lagrangian, corresponding to the weak field asymptotic expansion of the effective action to one-loop order. It is argued that the neutron might be a good candidate to probe this signal of nonlinearity in QED.

  19. Dipole-dipole-induced giant Goos-Hänchen shift in a photonic crystal doped with quantum dot nanostructures

    NASA Astrophysics Data System (ADS)

    Panahi, M.; Solookinejad, G.; Ahmadi Sangachin, E.; Hossein Asadpour, Seyyed

    2016-07-01

    The impact of the dipole-dipole interaction on the Goo-Hänchen (GH) shifts in reflected and transmitted lights is investigated. A weak probe beam is incident on a cavity containing the donor and acceptor quantum dots embedded in a nonlinear photonic crystal. We deduced that the GH shifts can be easily adjusted via controlling the corresponding parameters of the system in the presence or absence of dipole-dipole interaction. Our proposed model may be useful to developing the all-optical devices based on photonic materials doped with nanoparticles.

  20. Sub-Doppler laser cooling using electromagnetically induced transparency

    NASA Astrophysics Data System (ADS)

    He, Peiru; Tengdin, Phoebe M.; Anderson, Dana Z.; Rey, Ana Maria; Holland, Murray

    2017-05-01

    We propose a sub-Doppler laser-cooling mechanism that takes advantage of the unique spectral features and extreme dispersion generated by the phenomenon of electromagnetically induced transparency (EIT). EIT is a destructive quantum interference phenomenon experienced by atoms with multiple internal quantum states when illuminated by laser fields with appropriate frequencies. By detuning the lasers slightly from the "dark resonance," we observe that, within the transparency window, atoms can be subject to a strong viscous force, while being only slightly heated by the diffusion caused by spontaneous photon scattering. In contrast to other laser-cooling schemes, such as polarization gradient cooling or EIT-sideband cooling, no external magnetic field or strong external confining potential is required. Using a semiclassical approximation, we derive analytically quantitative expressions for the steady-state temperature, which is confirmed by full quantum mechanical numerical simulations. We find that the lowest achievable temperatures approach the single-photon recoil energy. In addition to dissipative forces, the atoms are subject to a stationary conservative potential, leading to the possibility of spatial confinement. We find that under typical experimental parameters, this effect is weak and stable trapping is not possible.

  1. The effect of electromagnetically induced transparency in a potassium nanocell

    NASA Astrophysics Data System (ADS)

    Sargsyan, A.; Amiryan, A.; Leroy, C.; Vartanyan, T. A.; Sarkisyan, D.

    2017-07-01

    The effect of electromagnetically induced transparency (EIT) has been experimentally implemented for the first time for the (4 S 1/2-4 P 1/2-4 S 1/2) Λ-system of potassium atom levels in a nanocell with a 770-nm-thick column of atomic vapor. It is shown that, at such a small thickness of the vapor column, the EIT resonance can be observed only when the coupling-laser frequency is in exact resonance with the frequency of the corresponding atomic transition. The EIT resonance disappears even if the coupling-laser frequency differs slightly (by 50 MHz) from that of the corresponding atomic transition, which is due to the high thermal velocity of K atoms. The EIT resonance and related velocity selective optical pumping resonances caused by optical pumping (formed by the coupling) can be simultaneously recorded because of the small ( 462 MHz) hyperfine splitting of the lower 4 S 1/2 level.

  2. Multiplexed image storage by electromagnetically induced transparency in a solid

    NASA Astrophysics Data System (ADS)

    Heinze, G.; Rentzsch, N.; Halfmann, T.

    2012-11-01

    We report on frequency- and angle-multiplexed image storage by electromagnetically induced transparency (EIT) in a Pr3+:Y2SiO5 crystal. Frequency multiplexing by EIT relies on simultaneous storage of light pulses in atomic coherences, driven in different frequency ensembles of the inhomogeneously broadened solid medium. Angular multiplexing by EIT relies on phase matching of the driving laser beams, which permits simultaneous storage of light pulses propagating under different angles into the crystal. We apply the multiplexing techniques to increase the storage capacity of the EIT-driven optical memory, in particular to implement multiplexed storage of larger two-dimensional amounts of data (images). We demonstrate selective storage and readout of images by frequency-multiplexed EIT and angular-multiplexed EIT, as well as the potential to combine both multiplexing approaches towards further enhanced storage capacities.

  3. Frequency-agile electromagnetically induced transparency analogue in terahertz metamaterials.

    PubMed

    Xu, Quan; Su, Xiaoqiang; Ouyang, Chunmei; Xu, Ningning; Cao, Wei; Zhang, Yuping; Li, Quan; Hu, Cong; Gu, Jianqiang; Tian, Zhen; Azad, Abul K; Han, Jiaguang; Zhang, Weili

    2016-10-01

    Recently reported active metamaterial analogues of electromagnetically induced transparency (EIT) are promising in developing novel optical components, such as active slow light devices. However, most of the previous works have focused on manipulating the EIT resonance strength at a fixed characteristic frequency and, therefore, realized on-to-off switching responses. To further extend the functionalities of the EIT effect, here we present a frequency tunable EIT analogue in the terahertz regime by integrating photoactive silicon into the metamaterial unit cell. A tuning range from 0.82 to 0.74 THz for the EIT resonance frequency is experimentally observed by optical pump-terahertz probe measurements, allowing a frequency tunable group delay of the terahertz pulses. This straightforward approach delivers frequency agility of the EIT resonance and may enable novel ultrafast tunable devices for integrated plasmonic circuits.

  4. Electromagnetically induced transparency and fluorescence in blockaded Rydberg atomic system.

    PubMed

    Li, Cheng; Zheng, Huaibin; Zhang, Zhaoyang; Yao, Xin; Zhang, Yunzhe; Zhang, Yiqi; Zhang, Yanpeng

    2013-10-28

    We investigate the interaction between dark states and Rydberg excitation blockade by using electromagnetically induced transparency (EIT), fluorescence, and four-wave mixing (FWM) signals both theoretically and experimentally. By scanning the frequency detunings of the probe and dressing fields, respectively, we first observe these signals (three coexisting EIT windows, two fluorescence signals, and two FWM signals) under Rydberg excitation blockade. Next, frequency detuning dependences of these signals are obtained, in which the modulated results are well explained by introducing the dressing effects (leading to the dark states) with the corrected factor of the Rydberg excitation blockade. In addition, the variations by changing the principal quantum number n of Rydberg state shown some interesting phenomena resulting from Rydberg blockade are observed. The unique nature of such blockaded signals can have potential application in the demonstration of quantum computing.

  5. Tailoring electromagnetically induced transparency with different coupling mechanisms

    PubMed Central

    Li, Hai-ming; Liu, Shao-bin; Wang, Shen-yun; Liu, Si-yuan; Hu, Yan; Li, Hai-bin

    2016-01-01

    Tailoring electromagnetically induced transparency with two different coupling mechanisms has been numerically demonstrated. The results show that EIT based on simultaneous electric resonance and magnetic resonance has relatively larger coupling distance compared with that based on electric resonance near field coupling to magnetic resonance. The relatively large coupling distance is due to the relatively small susceptibility change. For EIT based on simultaneous electric resonance and magnetic resonance, not only incident electric field but also the incident magnetic field pays a role on the susceptibility of system. The influence of the incident magnetic field leads to relatively smaller susceptibility change compared with that based on electric resonance near field coupling to magnetic resonance. PMID:26900016

  6. Coupled-resonator-induced-transparency concept for wavelength routing applications.

    PubMed

    Mancinelli, M; Guider, R; Bettotti, P; Masi, M; Vanacharla, M R; Pavesi, L

    2011-06-20

    The presence of coupled resonators induced transparency (CRIT) effects in side-coupled integrated spaced sequence of resonators (SCISSOR) of different radii has been studied. By controlling the rings radii and their center to center distance, it is possible to form transmission channels within the SCISSOR stop-band. Two different methods to exploit the CRIT effect in add/drop filters are proposed. Their performances, e. g. linewidth, crosstalk and losses, are examined also for random variations in the structural parameters. Finally, few examples of high performances mux/demux structures and 2 × 2 routers based on these modified SCISSOR are presented. CRIT based SCISSOR optical devices are particularly promising for ultra-dense wavelength division multiplexing applications.

  7. Electromagnetically induced transparency in paraffin-coated vapor cells

    SciTech Connect

    Klein, M.; Hohensee, M.; Walsworth, R. L.; Phillips, D. F.

    2011-01-15

    Antirelaxation coatings in atomic vapor cells allow ground-state coherent spin states to survive many collisions with the cell walls. This reduction in the ground-state decoherence rate gives rise to ultranarrow-bandwidth features in electromagnetically induced transparency (EIT) spectra, which can form the basis of, for example, long-time scale slow and stored light, sensitive magnetometers, and precise frequency standards. Here we study, both experimentally and theoretically, how Zeeman EIT contrast and width in paraffin-coated rubidium vapor cells are determined by cell and laser-beam geometry, laser intensity, and atomic density. Using a picture of Ramsey pulse sequences, where atoms alternately spend ''bright'' and ''dark'' time intervals inside and outside the laser beam, we explain the behavior of EIT features in coated cells, highlighting their unique characteristics and potential applications.

  8. Electromagnetically induced transparency in paraffin-coated vapor cells

    NASA Astrophysics Data System (ADS)

    Klein, M.; Hohensee, M.; Phillips, D. F.; Walsworth, R. L.

    2011-01-01

    Antirelaxation coatings in atomic vapor cells allow ground-state coherent spin states to survive many collisions with the cell walls. This reduction in the ground-state decoherence rate gives rise to ultranarrow-bandwidth features in electromagnetically induced transparency (EIT) spectra, which can form the basis of, for example, long-time scale slow and stored light, sensitive magnetometers, and precise frequency standards. Here we study, both experimentally and theoretically, how Zeeman EIT contrast and width in paraffin-coated rubidium vapor cells are determined by cell and laser-beam geometry, laser intensity, and atomic density. Using a picture of Ramsey pulse sequences, where atoms alternately spend “bright” and “dark” time intervals inside and outside the laser beam, we explain the behavior of EIT features in coated cells, highlighting their unique characteristics and potential applications.

  9. All-dielectric metasurface analogue of electromagnetically induced transparency.

    PubMed

    Yang, Yuanmu; Kravchenko, Ivan I; Briggs, Dayrl P; Valentine, Jason

    2014-12-16

    Metasurface analogues of electromagnetically induced transparency (EIT) have been a focus of the nanophotonics field in recent years, due to their ability to produce high-quality factor (Q-factor) resonances. Such resonances are expected to be useful for applications such as low-loss slow-light devices and highly sensitive optical sensors. However, ohmic losses limit the achievable Q-factors in conventional plasmonic EIT metasurfaces to values <~10, significantly hampering device performance. Here we experimentally demonstrate a classical analogue of EIT using all-dielectric silicon-based metasurfaces. Due to extremely low absorption loss and coherent interaction of neighbouring meta-atoms, a Q-factor of 483 is observed, leading to a refractive index sensor with a figure-of-merit of 103. Furthermore, we show that the dielectric metasurfaces can be engineered to confine the optical field in either the silicon resonator or the environment, allowing one to tailor light-matter interaction at the nanoscale.

  10. Coherent control of quantum fluctuations using cavity electromagnetically induced transparency.

    PubMed

    Souza, J A; Figueroa, E; Chibani, H; Villas-Boas, C J; Rempe, G

    2013-09-13

    We study the all-optical control of the quantum fluctuations of a light beam via a combination of single-atom cavity quantum electrodynamics (CQED) and electromagnetically induced transparency (EIT). Specifically, the EIT control field is used to tune the CQED transition frequencies in and out of resonance with the probe light. In this way, photon blockade and antiblockade effects are employed to produce sub-Poissonian and super-Poissonian light fields, respectively. The achievable quantum control paves the way towards the realization of a prototype of a novel quantum transistor which amplifies or attenuates the relative intensity noise of a light beam. Its feasibility is demonstrated by calculations using realistic parameters from recent experiments.

  11. Calculations of electrostatic properties in proteins. Analysis of contributions from induced protein dipoles.

    PubMed

    Van Belle, D; Couplet, I; Prevost, M; Wodak, S J

    1987-12-20

    The calculation of induced dipole moments and of their contribution to electrostatic effects in proteins is implemented following the approach of Warshel. Isotropic polarizabilities are assigned to individual atoms, and the resulting deviation from pairwise interactions is treated by a self-consistent iterative procedure. We give a detailed description of how the formalism is implemented in molecular mechanics and molecular dynamics simulation procedures, and report results based on calculations performed on crystal structures of crambin, liver alcohol dehydrogenase and ribonuclease T1. We focus our analysis on evaluating the contribution of polarizability of the protein matrix to electrostatic energies, local fields, to dipole moments of peptide groups and of secondary structure elements in the polypeptide chain. Our calculations confirm that induced dipole moments in proteins provide important stabilizing contributions to electrostatic energies, and that these contributions cannot be mimicked by the usual approximations where either a continuum dielectric constant, or a distance-dependent dielectric function is used. We find that induced protein dipoles appreciably affect the magnitude and direction of local electrostatic fields in a manner that is strongly influenced by the microscopic environment in the protein. Most strongly affected are fields in charged groups that are involved in close interactions with other charged groups, while the influence on local fields of aliphatic groups is marginal. We find, moreover, that induction effects from surrounding protein atoms tend on average to increase peptide dipoles and helix macro-dipoles by about 16%, again reflecting electrostatic stabilization by the protein matrix, and show that (at least in the alpha/beta domain of alcohol dehydrogenase) the contribution of side-chains to this stabilization is significant.

  12. What is and what is not electromagnetically induced transparency in whispering-gallery microcavities.

    PubMed

    Peng, Bo; Özdemir, Sahin Kaya; Chen, Weijian; Nori, Franco; Yang, Lan

    2014-10-24

    There has been an increasing interest in all-optical analogues of electromagnetically induced transparency and Autler-Townes splitting. Despite the differences in their underlying physics, both electromagnetically induced transparency and Autler-Townes splitting are quantified by a transparency window in the absorption or transmission spectrum, which often leads to a confusion about its origin. While the transparency window in electromagnetically induced transparency is a result of Fano interference among different transition pathways, in Autler-Townes splitting it is the result of strong field-driven interactions leading to the splitting of energy levels. Being able to tell objectively whether an observed transparency window is because of electromagnetically induced transparency or Autler-Townes splitting is crucial for applications and for clarifying the physics involved. Here we demonstrate the pathways leading to electromagnetically induced transparency, Fano resonances and Autler-Townes splitting in coupled whispering-gallery-mode resonators. Moreover, we report the application of the Akaike Information Criterion discerning between all-optical analogues of electromagnetically induced transparency and Autler-Townes splitting and clarifying the transition between them.

  13. Role of asymmetric environment on the dark mode excitation in metamaterial analogue of electromagnetically-induced transparency.

    PubMed

    Dong, Zheng-Gao; Liu, Hui; Xu, Ming-Xiang; Li, Tao; Wang, Shu-Ming; Cao, Jing-Xiao; Zhu, Shi-Ning; Zhang, X

    2010-10-11

    An otherwise dark magnetic dipole resonance in a split-ring resonator can be excited electrically with a Fano-type profile once the symmetric environment for this resonator is broken with respect to the polarized electric-field direction of incident waves. When this asymmetrically induced narrow resonance coincides with a broad dipolar resonance at an identical frequency regime, the metamaterial analogue of electromagnetically-induced transparency (EIT) window can be formed. We demonstrate that this environmental-asymmetry condition can be introduced dielectrically as well as plasmonically, either resonantly or nonresonantly, which indicates the plasmon coupling between different resonant modes is not responsible for the dark mode excitation. Thus, this result should contribute to the physical understanding on dark-mode excitation pathway for EIT-like phenomenon in plasmonic metamaterials.

  14. Geometry Optimization in Polarizable QM/MM Models: The Induced Dipole Formulation.

    PubMed

    Caprasecca, Stefano; Jurinovich, Sandro; Viani, Lucas; Curutchet, Carles; Mennucci, Benedetta

    2014-04-08

    We present the mathematical derivation and the computational implementation of the analytical geometry derivatives for a polarizable QM/MM model (QM/MMPol). In the adopted QM/MMPol model, the focused part is treated at QM level of theory, while the remaining part (the environment) is described classically as a set of fixed charges and induced dipoles. The implementation is performed within the ONIOM procedure, resulting in a polarizable embedding scheme, which can be applied to solvated and embedded systems and combined with different polarizable force fields available in the literature. Two test cases characterized by strong hydrogen-bond and dipole-dipole interactions, respectively, are used to validate the method with respect to the nonpolarizable one. Finally, an application to geometry optimization of the chromophore of Rhodopsin is presented to investigate the impact of including mutual polarization between the QM and the classical parts in conjugated systems.

  15. Sweetness-induced activation of membrane dipole potential in STC-1 taste cells.

    PubMed

    Chen, Li-Chun; Xie, Ning-Ning; Deng, Shao-Ping

    2016-12-01

    The biological functions of cell membranes strongly influence the binding and transport of molecular species. We developed STC-1 cell line stably expressing the sweet taste receptor (T1R2/T1R3), and explored the possible correlation between sweeteners and membrane dipole potential of STC-1 cells. In this study, sweetener-induced dipole potential activation was elucidated using a fluorescence-based measurement technique, by monitoring the voltage sensitive probe Di-8-ANEPPS using a dual wavelength ratiometric approach. It indicated that the presence of sweeteners resulted in cell membrane dipole potential change, and interaction of artificial sweeteners with taste cells resulted in a greater reduction in potential compared with natural sweeteners. Our work presents a newly developed approach using a fluorescence-based measurement technique to study sweetener-induced dipole potential activation of STC-1 cells. This new approach could be used as a complementary tool to study the function of sweet taste receptors or other GPCRs and helps to understand the basis sweetness mechanism.

  16. Electromagnetically induced transparency resonances inverted in magnetic field

    SciTech Connect

    Sargsyan, A.; Sarkisyan, D. E-mail: david@ipr.sci.am; Pashayan-Leroy, Y.; Leroy, C.; Cartaleva, S.; Wilson-Gordon, A. D.; Auzinsh, M.

    2015-12-15

    The phenomenon of electromagnetically induced transparency (EIT) is investigated in a Λ-system of the {sup 87}Rb D{sub 1} line in an external transverse magnetic field. Two spectroscopic cells having strongly different values of the relaxation rates γ{sub rel} are used: an Rb cell with antirelaxation coating (L ∼ 1 cm) and an Rb nanometric- thin cell (nanocell) with a thickness of the atomic vapor column L = 795 nm. For the EIT in the nanocell, we have the usual EIT resonances characterized by a reduction in the absorption (dark resonance (DR)), whereas for the EIT in the Rb cell with an antirelaxation coating, the resonances demonstrate an increase in the absorption (bright resonances (BR)). We suppose that such an unusual behavior of the EIT resonances (i.e., the reversal of the sign from DR to BR) is caused by the influence of an alignment process. The influence of alignment strongly depends on the configuration of the coupling and probe frequencies as well as on the configuration of the magnetic field.

  17. Handedness Dependent Electromagnetically Induced Transparency in Hybrid Chiral Metamaterials

    PubMed Central

    Kang, Lei; Hao Jiang, Zhi; Yue, Taiwei; Werner, Douglas H.

    2015-01-01

    We provide the first experimental demonstration of the handedness dependent electromagnetically induced transparency (EIT) in chiral metamaterials during the interaction with circularly polarized waves. The observed chiral-sensitive EIT phenomena arise from the coherent excitation of a non-radiative mode in the component split ring resonators (SRRs) produced by the corresponding Born−Kuhn type (radiative) resonators that are responsible for the pronounced chirality. The coherent coupling, which is dominated by the bonding and antibonding resonances of the Born−Kuhn type resonators, leads to an extremely steep dispersion for a circularly polarized wave of predefined handedness. Accordingly, retrieved effective medium parameters from simulated results further reveal a difference of 80 in the group indices for left- and right-handed circularly polarized waves at frequencies within the EIT window, which can potentially result in handedness-sensitive pulse delays. These chiral metamaterials which enable a handedness dependent EIT effect may provide more degrees of freedom for designing circular polarization based communication devices. PMID:26183735

  18. Handedness Dependent Electromagnetically Induced Transparency in Hybrid Chiral Metamaterials

    NASA Astrophysics Data System (ADS)

    Kang, Lei; Hao Jiang, Zhi; Yue, Taiwei; Werner, Douglas H.

    2015-07-01

    We provide the first experimental demonstration of the handedness dependent electromagnetically induced transparency (EIT) in chiral metamaterials during the interaction with circularly polarized waves. The observed chiral-sensitive EIT phenomena arise from the coherent excitation of a non-radiative mode in the component split ring resonators (SRRs) produced by the corresponding Born-Kuhn type (radiative) resonators that are responsible for the pronounced chirality. The coherent coupling, which is dominated by the bonding and antibonding resonances of the Born-Kuhn type resonators, leads to an extremely steep dispersion for a circularly polarized wave of predefined handedness. Accordingly, retrieved effective medium parameters from simulated results further reveal a difference of 80 in the group indices for left- and right-handed circularly polarized waves at frequencies within the EIT window, which can potentially result in handedness-sensitive pulse delays. These chiral metamaterials which enable a handedness dependent EIT effect may provide more degrees of freedom for designing circular polarization based communication devices.

  19. Laser frequency locking based on Rydberg electromagnetically induced transparency

    NASA Astrophysics Data System (ADS)

    Yuechun, Jiao; Jingkui, Li; Limei, Wang; Hao, Zhang; Linjie, Zhang; Jianming, Zhao; Suotang, Jia

    2016-05-01

    We present a laser frequency locking to Rydberg transition with electromagnetically induced transparency (EIT) spectra in a room-temperature cesium vapor cell. Cesium levels 6S1/2, 6P3/2, and the nD5/2 state, compose a cascade three-level system, where a coupling laser drives Rydberg transition, and probe laser detects the EIT signal. The error signal, obtained by demodulating the EIT signal, is used to lock the coupling laser frequency to Rydberg transition. The laser frequency fluctuation, ˜0.7 MHz, is obtained after locking on, with the minimum Allan variance to be 8.9 × 10-11. This kind of locking method can be used to stabilize the laser frequency to the excited transition. Project supported by the National Basic Research Program of China (Grant No. 2012CB921603), the National Natural Science Foundation of China (Grants Nos. 11274209, 61475090, 61378039, and 61378013), and the Research Project Supported by Shanxi Scholarship Council of China (Grant No. 2014-009).

  20. Tunable multispectral plasmon induced transparency based on graphene metamaterials.

    PubMed

    Sun, Chen; Si, Jiangnan; Dong, Zhewei; Deng, Xiaoxu

    2016-05-30

    A dynamically wavelength tunable multispectral plasmon induced transparency (PIT) device based on graphene metamaterials, which is composed of periodically patterned graphene double layers separated by a dielectric layer, is proposed theoretically and numerically in the terahertz frequency range. Considering the near-field coupling of different graphene layers and the bright-dark mode coupling in the same graphene layer, the coupled Lorentz oscillator model is adapted to explain the physical mechanism of multispectral EIT-like responses. The simulated transmission based on the finite-difference time-domain (FDTD) solutions indicates that the shifting and depth of the EIT resonances in multiple PIT windows are controlled by different geometrical parameters and Fermi energies distributions. A design scheme with graphene integration is employed, which allows independent tuning of resonance frequencies by electrostatically changing the Fermi energies of graphene double layer. Active control of the multispectral EIT-like responses enables the proposed device to be widely applied in optical information processing as tunable sensors, switches, and filters.

  1. Entangler via electromagnetically induced transparency with an atomic ensemble

    PubMed Central

    Yang, Xihua; Zhou, Yuanyuan; Xiao, Min

    2013-01-01

    Quantum entanglement plays an essential role in quantum information processing and quantum networks. One of the commonly-used methods to generate multiple entangled fields is to employ polarizing beam splitters. However, nonclassical input light fields are required and the generated entangled fields are always degenerate in such case. Here, we present a proof-of-principle demonstration of an efficient and convenient way to entangle multiple light fields via electromagnetically induced transparency (EIT) in an atomic ensemble. The atomic spin wave, produced through EIT in the Λ-type atomic system, can be described by a Bose operator and can act as an entangler. With such an entangler, any desired number of nondegenerate narrow-band continuous-variable entangled fields, in principle, can be generated through stimulated Raman scattering processes. This scheme holds great promise for applications in scalable quantum communication and quantum networks. PACS: 42.50.Gy, 03.67.Bg, 42.50.Dv, 42.65.Lm. PMID:24327253

  2. Electromagnetically induced transparency-assisted four-wave mixing process in the diamond-type four-level atomic system

    NASA Astrophysics Data System (ADS)

    Wen, Feng; Zheng, Huaibin; Xue, Xinxin; Chen, Haixia; Song, Jianping; Zhang, Yanpeng

    2014-11-01

    With electromagnetically induced transparency (EIT)-assisted configuration, we study the third-order nonlinear four-wave mixing (FWM) process in a diamond-type four-level atomic system both theoretically and experimentally. Following the proposal by the recent study (Willis et al., 2009), we introduce EIT contribution to the theoretical model which will enhance the conversion efficiency of the nonlinear process and narrow the linewidth of the FWM signal. By means of the coherent EIT effect, we get higher conversion efficiency at lower power level of incident beam in such atomic system. Compare to our previous models, the conversion efficiency in such diamond-type atomic system is much smaller which needs higher threshold temperature. In addition, the frequency dependences on incident beams reveal that the dipole transition of one-photon and two-photon processes affect this nonlinear process.

  3. Experimental Studies of Laser-Induced Breakdown in Transparent Dielectrics

    SciTech Connect

    Carr, Christopher Wren

    2003-09-23

    The mechanisms by which transparent dielectrics damage when exposed to high power laser radiation has been of scientific and technological interest since the invention of the laser. In this work, a set of three experiments are presented which provide insight into the damage initiation mechanisms and the processes involved in laser-induced damage. Using an OPO (optical parametric oscillator) laser, we have measured the damage thresholds of deuterated potassium dihydrogen phosphate (DKDP) from the near ultraviolet into the visible. Distinct steps, whose width is of order KbT, are observed in the damage threshold at photon energies associated with the number of photons (3→2 or 4→3) needed to promote a ground state electron across the energy gap. The wavelength dependence of the damage threshold suggests that a primary mechanism for damage initiation in DKDP is a multi-photon process in which the order is reduced through excited defect state absorption. In-situ fluorescence microscopy, in conjunction with theoretical calculations by Liu et al., has been used to establish that hydrogen displacement defects are potentially responsible for the reduction in the multi-photon cross-section. During the damage process, the material absorbs energy from the laser pulse and produces an ionized region that gives rise to broadband emission. By performing a time-resolved investigation of this emission, we demonstrate both that it is blackbody in nature, and we provide the first direct measurement of the localized temperature during and following laser damage initiation for various optical materials. For excitation using nanosecond laser pulses, the plasma, when confined in the bulk, is in thermal equilibrium with the lattice. These results allow for a detailed characterization of temperature, pressure, and electron densities occurring during laser-induced damage.

  4. Acoustically induced transparency in optically dense resonance medium.

    PubMed

    Radeonychev, Y V; Tokman, M D; Litvak, A G; Kocharovskaya, Olga

    2006-03-10

    It is shown that mechanical vibration (acoustical oscillation) of a solid medium along the propagation of multifrequency laser radiation enables one to control the resonant absorption. There exists an optimal spectral structure of the incident field dependent on vibration amplitude as well as the number and intensity of the frequency components that provides the full resonant transparency. A mechanism of the transparency is discussed. Transparency of this kind is shown to appear also via adiabatic modulation of the atomic transition frequency by an external microwave field.

  5. Polarization-independent transparency window induced by complementary graphene metasurfaces

    NASA Astrophysics Data System (ADS)

    Lu, Wei Bing; Liu, Ji Long; Zhang, Jin; Wang, Jian; Liu, Zhen Guo

    2017-01-01

    A fourfold symmetric graphene-based complementary metasurface featuring a polarization-independent transparency window is proposed and numerically analysed in this paper. The unit cell of the metamaterial consists of a monolayer graphene perforated with a cross and four identical split-ring resonators deposited on a substrate. Our analysis shows that the transparency window can be interpreted as a plasmonic analogy of Autler-Townes splitting. The polarization independence is achieved due to the fourfold symmetry of graphene’s complementary structure. In addition, the frequency range of the transparency window can be dynamically tuned over a broad band by changing the chemical potential of graphene, and the width of the transparency window can also be controlled by changing the split-gap orientation. This work may lead to potential applications in many area, such as slow-light devices and optical sensing.

  6. Phase Jumps in an Electro-magnetically Induced Transparency System

    NASA Astrophysics Data System (ADS)

    Narducci, F. A.; Noble, J.; Welch, G. R.; Davis, J. P.

    2010-03-01

    We have taken a closer look at the dynamics of an EIT system when the relative phase of the two lasers is abruptly changed. The absorption of the probe field rapidly increases to a value that can exceed even the ordinary two-level absorption, then slowly decays back down to the induced transparency level. This system has been previously studied by some of us theoretically [1] and experimentally [2,3]. We show that the timescale for the rapid rise is set by the inverse bandwidth of the medium in the absence of the pump field and is therefore dramatically different for a room temperature cell as for a laser cooled sample. We also show that, surprisingly, the slow decay is not dependent on the ground state coherence time, but rather, the interplay between the Rabi frequencies and the excited state spontaneous emission rate. This suggests that, theoretically, the rise time can be made arbitrarily fast, while, simultaneously, the decay time can be made arbitrarily small or even zero. We draw a comparison with experiments performed in a warm cell and in experiments being conducted in a cold sample of atoms. [1] T. Abi-salloum, J.P. Davis, C. Lehman, E. Elliott, F.A. Narducci, J. Mod. Opt, 54, 2459-2471, (2007). [2] V.A. Sautenkov, H. Li, Y.V. Rostovtsev, G.R. Welch, J.P. Davis, F.A. Narducci, M. O. Scully, J. Mod. Opt, 55, 3093-3099, (2008). [3] V.A. Sautenkov, H. Li, Y.V. Rostovtsev, G.R. Welch, J.P. Davis, F.A. Narducci, M.O. Scully, J. Mod. Opt, 56, 975-979, (2009).

  7. Dipole potentials indicate restructuring of the membrane interface induced by gadolinium and beryllium ions

    NASA Technical Reports Server (NTRS)

    Ermakov, Y. A.; Averbakh, A. Z.; Yusipovich, A. I.; Sukharev, S.

    2001-01-01

    The dipole component of the membrane boundary potential, phi(d), is an integral parameter that may report on the conformational state of the lipid headgroups and their hydration. In this work, we describe an experimental approach to measurements of the dipole potential changes, Deltaphi(d), and apply it in studies of Be(2+) and Gd(3+) interactions with membranes composed of phosphatidylserine (PS), phosphatidylcholine (PC), and their mixtures. Deltaphi(d) is determined as the difference between the changes of the total boundary potential, phi(b), measured by the IFC method in planar lipid membranes and the surface potential, phi(s), determined from the electrophoretic mobility of liposomes. The Gouy-Chapman-Stern formalism, combined with the condition of mass balance, well describes the ion equilibria for these high-affinity cations. For the adsorption of Be(2+) and Gd(3+) to PC membranes, and of Mg(2+) to PS membranes, the values of Deltaphi(b) and Deltaphi(s) are the same, indicative of no change of phi(d). Binding of Gd(3+) to PS-containing membranes induces changes of phi(d) of opposite signs depending on the density of ionized PS headgroups in the bilayer. At low density, the induced Deltaphi(d) is negative (-30 mV), consistent with the effect of dehydration of the surface. At maximal density (pure PS, neutral pH), adsorption of Be(2+) or Gd(3+) induces an increase of phi(d) of 35 or 140 mV, respectively. The onset of the strong positive dipole effect on PS membranes with Gd(3+) is observed near the zero charge point and correlates with a six-fold increase of membrane tension. The observed phenomena may reflect concerted reorientation of dipole moments of PS headgroups as a result of ion adsorption and lipid condensation. Their possible implications to in-vivo effects of these high-affinity ions are discussed.

  8. Interacting He and Ar atoms: Revised theoretical interaction potential, dipole moment, and collision-induced absorption spectra

    SciTech Connect

    Meyer, Wilfried; Frommhold, Lothar

    2015-09-21

    Coupled cluster quantum chemical calculations of the potential energy surface and the induced dipole surface are reported for the He–Ar van der Waals collisional complex. Spectroscopic parameters are derived from global analytical fits while an accurate value for the long-range dipole coefficient D{sub 7} is obtained by perturbation methods. Collision-induced absorption spectra are computed quantum mechanically and compared with existing measurements.

  9. Interacting He and Ar atoms: Revised theoretical interaction potential, dipole moment, and collision-induced absorption spectra.

    PubMed

    Meyer, Wilfried; Frommhold, Lothar

    2015-09-21

    Coupled cluster quantum chemical calculations of the potential energy surface and the induced dipole surface are reported for the He-Ar van der Waals collisional complex. Spectroscopic parameters are derived from global analytical fits while an accurate value for the long-range dipole coefficient D7 is obtained by perturbation methods. Collision-induced absorption spectra are computed quantum mechanically and compared with existing measurements.

  10. The effect of Thole functions on the simulation of ionic liquids with point induced dipoles at various densities.

    PubMed

    Taylor, Thomas; Schmollngruber, Michael; Schröder, Christian; Steinhauser, Othmar

    2013-05-28

    Point-induced dipoles are used to mimic electronic degrees of freedom in molecular dynamics simulations. Ultrashort distance interactions of these induced dipoles are damped by the so-called Thole functions to avoid the "polarization catastrophe." This study aims at the overall impact of Thole functions on structure as well as single-particle and collective dynamics of the ionic liquid 1-ethyl-3-methylimidazolium trifluoromethylsulfonate and thereby extends common studies of the effect of Thole functions on energy minimized geometries.

  11. Dipole-induced vortex ratchets in superconducting films with arrays of micromagnets.

    PubMed

    de Souza Silva, C C; Silhanek, A V; Van de Vondel, J; Gillijns, W; Metlushko, V; Ilic, B; Moshchalkov, V V

    2007-03-16

    We investigate the transport properties of superconducting films with periodic arrays of in-plane magnetized micromagnets. Two different magnetic textures are studied: a square array of magnetic bars and a close-packed array of triangular microrings. As confirmed by magnetic force microscopy imaging, the magnetic state of both systems can be adjusted to produce arrays of almost pointlike magnetic dipoles. By carrying out transport measurements with ac drive, we observed experimentally a recently predicted ratchet effect induced by the interaction between superconducting vortices and the magnetic dipoles. Moreover, we find that these magnetic textures produce vortex-antivortex patterns, which have a crucial role in the transport properties of this hybrid system.

  12. FOURTH SEMINAR TO THE MEMORY OF D.N. KLYSHKO: Pulsed transparency of anisotropic media with Stark level broadening

    NASA Astrophysics Data System (ADS)

    Sazonov, Sergei V.; Ustinov, N. V.

    2005-08-01

    The propagation of few-cycle electromagnetic pulses through an anisotropic medium is considered. The effect of a constant dipole moment of the resonance transition on the formation of self-induced transparency pulses and their spectral composition is studied.

  13. Tunable electromagnetically induced transparency in coupled three-dimensional split-ring-resonator metamaterials

    NASA Astrophysics Data System (ADS)

    Han, Song; Cong, Longqing; Lin, Hai; Xiao, Boxun; Yang, Helin; Singh, Ranjan

    2016-02-01

    Metamaterials have recently enabled coupling induced transparency due to interference effects in coupled subwavelength resonators. In this work, we present a three dimensional (3-D) metamaterial design with six-fold rotational symmetry that shows electromagnetically induced transparency with a strong polarization dependence to the incident electromagnetic wave due to the ultra-sharp resonance line width as a result of interaction between the constituent meta-atoms. However, when the six-fold rotationally symmetric unit cell design was re-arranged into a fourfold rotational symmetry, we observed the excitation of a polarization insensitive dual-band transparency. Thus, the 3-D split-ring resonators allow new schemes to observe single and multi-band classical analogues of electromagnetically induced transparencies that has huge potential applications in slowing down light, sensing modalities, and filtering functionalities either in the passive mode or the active mode where such effects could be tuned by integrating materials with dynamic properties.

  14. Tunable electromagnetically induced transparency in coupled three-dimensional split-ring-resonator metamaterials

    PubMed Central

    Han, Song; Cong, Longqing; Lin, Hai; Xiao, Boxun; Yang, Helin; Singh, Ranjan

    2016-01-01

    Metamaterials have recently enabled coupling induced transparency due to interference effects in coupled subwavelength resonators. In this work, we present a three dimensional (3-D) metamaterial design with six-fold rotational symmetry that shows electromagnetically induced transparency with a strong polarization dependence to the incident electromagnetic wave due to the ultra-sharp resonance line width as a result of interaction between the constituent meta-atoms. However, when the six-fold rotationally symmetric unit cell design was re-arranged into a fourfold rotational symmetry, we observed the excitation of a polarization insensitive dual-band transparency. Thus, the 3-D split-ring resonators allow new schemes to observe single and multi-band classical analogues of electromagnetically induced transparencies that has huge potential applications in slowing down light, sensing modalities, and filtering functionalities either in the passive mode or the active mode where such effects could be tuned by integrating materials with dynamic properties. PMID:26857034

  15. Slowing the probe field in the second window of double-double electromagnetically induced transparency

    NASA Astrophysics Data System (ADS)

    Alotaibi, Hessa M. M.; Sanders, Barry C.

    2015-04-01

    For Doppler-broadened media operating under double-double electromagnetically induced transparency (EIT) conditions, we devise a scheme to control and reduce the probe-field group velocity at the center of the second transparency window. We derive numerical and approximate analytical solutions for the width of EIT windows and for the group velocities of the probe field at the two distinct transparency windows, and we show that the group velocities of the probe field can be lowered by judiciously choosing the physical parameters of the system. Our modeling enables us to identify three signal-field strength regimes (with a signal-field strength always higher than the probe-field strength), quantified by the Rabi frequency, for slowing the probe field. These three regimes correspond to a weak signal field, with the probe-field group velocity and transparency-window width both smaller for the second window compared to the first window, a medium-strength signal field, with a probe-field group velocity smaller in the second window than in the first window but with larger transparency-window width for the second window, and the strong signal field, with both group velocity and transparency-window width larger for the second window. Our scheme exploits the fact that the second transparency window is sensitive to a temperature-controlled signal-field nonlinearity, whereas the first transparency window is insensitive to this nonlinearity.

  16. Mapping the Drude polarizable force field onto a multipole and induced dipole model

    NASA Astrophysics Data System (ADS)

    Huang, Jing; Simmonett, Andrew C.; Pickard, Frank C.; MacKerell, Alexander D.; Brooks, Bernard R.

    2017-10-01

    The induced dipole and the classical Drude oscillator represent two major approaches for the explicit inclusion of electronic polarizability into force field-based molecular modeling and simulations. In this work, we explore the equivalency of these two models by comparing condensed phase properties computed using the Drude force field and a multipole and induced dipole (MPID) model. Presented is an approach to map the electrostatic model optimized in the context of the Drude force field onto the MPID model. Condensed phase simulations on water and 15 small model compounds show that without any reparametrization, the MPID model yields properties similar to the Drude force field with both models yielding satisfactory reproduction of a range of experimental values and quantum mechanical data. Our results illustrate that the Drude oscillator model and the point induced dipole model are different representations of essentially the same physical model. However, results indicate the presence of small differences between the use of atomic multipoles and off-center charge sites. Additionally, results on the use of dispersion particle mesh Ewald further support its utility for treating long-range Lennard Jones dispersion contributions in the context of polarizable force fields. The main motivation in demonstrating the transferability of parameters between the Drude and MPID models is that the more than 15 years of development of the Drude polarizable force field can now be used with MPID formalism without the need for dual-thermostat integrators nor self-consistent iterations. This opens up a wide range of new methodological opportunities for polarizable models.

  17. Phase-coupled plasmon-induced transparency in integrated metal–dielectric–graphene–dielectric waveguide

    NASA Astrophysics Data System (ADS)

    Yao, Xin-Tao; Lin, Qi; Zhai, Xiang; Su, Yi; Liang, Mei-Zhen; Liang, Mei-Zhu; Wang, Ling-Ling

    2017-10-01

    We theoretically and numerically investigate the phase-coupled plasmon-induced transparency effect in graphene plasmonic systems that consist of multiple cascade graphene nanoribbon resonators side-coupled to the bus waveguide. The formation of a transparency window is attributed to the superposition of the detuned resonances in graphene nanoribbons. The gap width between the metal and the graphene provides a new degree of freedom for controlling the round-trip phase accumulated in the bus waveguide, which determines the evolution of the transparency window in terms of intensity and symmetry. Our ultracompact configuration can realize slow light with group indices over 250 as well as retain high transmission intensity.

  18. Tunable terahertz electromagnetically induced transparency based on a complementary graphene metamaterial

    NASA Astrophysics Data System (ADS)

    Zhang, Huiyun; Zhang, Xiaoqiuyan; Cao, Yanyan; Zeng, Beibei; Zhou, Mingdong; Zhang, Yuping

    2017-01-01

    We proposed a dynamically tunable electromagnetically induced transparency (EIT) in the terahertz region based on a complementary graphene metamaterials within two asymmetric slot structures. A transparency peak is enabled through the coupling between the asymmetric slot-structure elements when their symmetry is broken. The width of transparency window can be controlled by varying the asymmetry degree. Moreover, by varying the Fermi energy of graphene, the transmission peak can be dynamically tuned, realizing a blue-shift without re-optimizing or re-fabricating the nanostructure. Therefore, the work opens up opportunities for the development of tunable compact elements such as slow light devices, sensors and switches.

  19. Cold-atom physics using ultrathin optical fibers: light-induced dipole forces and surface interactions.

    PubMed

    Sagué, G; Vetsch, E; Alt, W; Meschede, D; Rauschenbeutel, A

    2007-10-19

    The strong evanescent field around ultrathin unclad optical fibers bears a high potential for detecting, trapping, and manipulating cold atoms. Introducing such a fiber into a cold-atom cloud, we investigate the interaction of a small number of cold cesium atoms with the guided fiber mode and with the fiber surface. Using high resolution spectroscopy, we observe and analyze light-induced dipole forces, van der Waals interaction, and a significant enhancement of the spontaneous emission rate of the atoms. The latter can be assigned to the modification of the vacuum modes by the fiber.

  20. Positronium-dipole induced resonances in e +-H and e +-alkali systems

    NASA Astrophysics Data System (ADS)

    Umair, M.; Jonsell, S.

    2017-02-01

    We derive general universal scaling relations governing resonances induced by the dipole moment of excited positronium interacting with atomic ions. A single non-universal parameter, which contains all the system-dependent information, is defined. Our results are compared to numerical calculations, using complex scaling, for S, P, and D-wave resonances below the positronium n = 2 threshold in the {{e}}+-(H, Li, Na, K) systems. The energy and width ratios of the successive resonances are found to agree well with the analytically derived scaling law.

  1. Experimental realization of an on-chip all-optical analogue to electromagnetically induced transparency.

    PubMed

    Xu, Qianfan; Sandhu, Sunil; Povinelli, Michelle L; Shakya, Jagat; Fan, Shanhui; Lipson, Michal

    2006-03-31

    We provide the first experimental observation of structure tuning of the electromagnetically induced transparency-like spectrum in integrated on-chip optical resonator systems. The system consists of coupled silicon ring resonators with 10 microm diameter on silicon, where the coherent interference between the two coupled resonators is tuned. We measured a transparency-resonance mode with a quality factor of 11,800.

  2. Formation and evolution mechanisms of plasmon-induced transparency in MDM waveguide with two stub resonators.

    PubMed

    Cao, Guangtao; Li, Hongjian; Zhan, Shiping; Xu, Haiqing; Liu, Zhimin; He, Zhihui; Wang, Yun

    2013-04-22

    We demonstrate the realization of plasmonic analog of electromagnetically induced transparency (EIT) in a system composing of two stub resonators side-coupled to metal-dielectric-metal (MDM) waveguide. Based on the coupled mode theory (CMT) and Fabry-Perot (FP) model, respectively, the formation and evolution mechanisms of plasmon-induced transparency by direct and indirect couplings are exactly analyzed. For the direct coupling between the two stub resonators, the FWHM and group index of transparent window to the inter-space are more sensitive than to the width of one cut, and the high group index of up to 60 can be achieved. For the indirect coupling, the formation of transparency window is determined by the resonance detuning, but the evolution of transparency is mainly attributed to the change of coupling distance. The consistence between the analytical solution and finite-difference time-domain (FDTD) simulations verifies the feasibility of the plasmon-induced transparency system. It is also interesting to notice that the scheme is easy to be fabricated and may pave the way to highly integrated optical circuits.

  3. Interaction-induced dipoles of hydrogen molecules colliding with helium atoms: a new ab initio dipole surface for high-temperature applications.

    PubMed

    Li, Xiaoping; Mandal, Anirban; Miliordos, Evangelos; Hunt, Katharine L C

    2012-01-28

    We report new ab initio results for the interaction-induced dipole moments Δμ of hydrogen molecules colliding with helium atoms. These results are needed in order to calculate collision-induced absorption spectra at high temperatures; applications include modeling the radiative profiles of very cool white dwarf stars, with temperatures from 3500 K to 9000 K. We have evaluated the dipoles based on finite-field calculations, with coupled cluster methods in MOLPRO 2006 and aug-cc-pV5Z (spdfg) basis sets for both the H and He centers. We have obtained values of Δμ for eight H(2) bond lengths ranging from 0.942 a.u. to 2.801 a.u., for 15 intermolecular separations R ranging from 2.0 a.u. to 10.0 a.u., and for 19 different relative orientations. In general, our values agree well with earlier ab initio results, for the geometrical configurations that are treated in common, but we have determined more points on the collision-induced dipole surface by an order of magnitude. These results make it possible to calculate transition probabilities for molecules in excited vibrational states, overtones, and rotational transitions with ΔJ > 4. We have cast our results in the symmetry-adapted form needed for absorption line shape calculations, by expressing Δμ as a series in the spherical harmonics of the orientation angles of the intermolecular vector and of a unit vector along the H(2) bond axis. The expansion coefficients depend on the H(2) bond length and the intermolecular distance R. For large separations R, we show that the ab initio values of the leading coefficients converge to the predictions from perturbation theory, including both classical multipole polarization and dispersion effects. © 2012 American Institute of Physics

  4. Transparency under double detuning-induced stimulated Raman adiabatic passage in atoms with hyperfine structure

    NASA Astrophysics Data System (ADS)

    Deng, Li; Nakajima, Takashi; Gong, Shangqing

    2017-06-01

    We theoretically study the transparency in the generalized two-level system with hyperfine structure by utilizing double detuning-induced stimulated Raman adiabatic passage (double D-STIRAP). The double D-STIRAP is carried out by sequentially applying the three pulses, one near-resonant pump pulse and two far-off resonant Stark pulses before and after the pump pulse. From the study of single-atom response we can roughly learn the transparency conditions, since the full recovery of the system to the initial state is associated with the perfect transparency. After the numerical calculations we find that, for the perfect transparency, the pulse intensities of double D-STIRAP for the generalized two-level systems with hyperfine structure has to be stronger than that for the ideal two-level system. More precisely, we find that the ratio of amplitude to time for the Rabi frequency of the pump pulse and the detuning induced by the Stark pulse have to be close to each other to satisfy the adiabatic conditions. The above conditions, however, are necessary conditions we can learn from the single-atom response, and to ensure that they are indeed sufficient for perfect transparency, we perform the propagation calculations to obtain the temporal profile of the pump pulse at arbitrary propagation depths to find that double D-STIRAP, when applied to the generalized two-level system with hyperfine structure, is indeed robust for perfect transparency.

  5. Tunable optical analog to electromagnetically induced transparency in graphene-ring resonators system

    NASA Astrophysics Data System (ADS)

    Wang, Yonghua; Xue, Chenyang; Zhang, Zengxing; Zheng, Hua; Zhang, Wendong; Yan, Shubin

    2016-12-01

    The analogue of electromagnetically induced transparency in optical ways has shown great potential in optical delay and quantum-information technology due to its flexible design and easy implementation. The chief drawback for these devices is the bad tunability. Here we demonstrate a tunable optical transparency system formed by graphene-silicon microrings which could control the transparent window by electro-optical means. The device consists of cascaded coupled ring resonators and a graphene/graphene capacitor which integrated on one of the rings. By tuning the Fermi level of the graphene sheets, we can modulate the round-trip ring loss so that the transparency window can be dynamically tuned. The results provide a new method for the manipulation and transmission of light in highly integrated optical circuits and quantum information storage devices.

  6. Tuning all-Optical Analog to Electromagnetically Induced Transparency in nanobeam cavities using nanoelectromechanical system

    PubMed Central

    Shi, Peng; Zhou, Guangya; deng, Jie; Tian, Feng; Chau, Fook Siong

    2015-01-01

    We report the observations of all-optical electromagnetically induced transparency in nanostructures using waveguide side-coupled with photonic crystal nanobeam cavities, which has measured linewidths much narrower than individual resonances. The quality factor of transparency resonance can be 30 times larger than those of measured individual resonances. When the gap between cavity and waveguide is reduced to 10 nm, the bandwidth of destructive interference region can reach 10 nm while the width of transparency resonance is 0.3 nm. Subsequently, a comb-drive actuator is introduced to tune the line shape of the transparency resonance. The width of the peak is reduced to 15 pm and the resulting quality factor exceeds 105. PMID:26415907

  7. Active control and switching of broadband electromagnetically induced transparency in symmetric metadevices

    NASA Astrophysics Data System (ADS)

    Yahiaoui, Riad; Manjappa, Manukumara; Srivastava, Yogesh Kumar; Singh, Ranjan

    2017-07-01

    Electromagnetically induced transparency (EIT) arises from coupling between the bright and dark mode resonances that typically involve subwavelength structures with broken symmetry, which results in an extremely sharp transparency band. Here, we demonstrate a tunable broadband EIT effect in a symmetry preserved metamaterial structure at the terahertz frequencies. Alongside, we also envisage a photo-active EIT effect in a hybrid metal-semiconductor metamaterial, where the transparency window can be dynamically switched by shining near-infrared light beam. A robust coupled oscillator model explains the coupling mechanism in the proposed design, which shows a good agreement with the observed results on tunable broadband transparency effect. Such active, switchable, and broadband metadevices could have applications in delay bandwidth management, terahertz filtering, and slow light effects.

  8. Influence of Doppler effect on the phenomenon of electromagnetically induced transparency

    NASA Astrophysics Data System (ADS)

    Tao, Qiyong; Zhang, Guiyin; Zheng, Haiming

    2016-11-01

    Electromagnetically induced transparency (EIT) is a significant nonlinear optical phenomenon. Based on the theory of density matrix equation, we presented the influence of Doppler effect on EIT. A cascade type three-level system and Na atomic vapor is adopted during the course. The results showed that EIT is determined by Rabi frequency of the couple and probing field. It is independent of temperature usually. But when we take Doppler effect into account, it is found that the full transparency appeared at the condition of ΩP=0.01GHz, ΩC=1GHz will vary with temperature. An obvious transparent window can be observed only when the temperature is less than 50K. With the increase of temperature, EIT phenomenon disappeared quickly. At room temperature, we can see that the double peaks of Aulter-Townes will instead of the EIT transparent window as Rabi frequency of the couple field is larger than 1.5GHz.

  9. Tunable optical analog to electromagnetically induced transparency in graphene-ring resonators system.

    PubMed

    Wang, Yonghua; Xue, Chenyang; Zhang, Zengxing; Zheng, Hua; Zhang, Wendong; Yan, Shubin

    2016-12-12

    The analogue of electromagnetically induced transparency in optical ways has shown great potential in optical delay and quantum-information technology due to its flexible design and easy implementation. The chief drawback for these devices is the bad tunability. Here we demonstrate a tunable optical transparency system formed by graphene-silicon microrings which could control the transparent window by electro-optical means. The device consists of cascaded coupled ring resonators and a graphene/graphene capacitor which integrated on one of the rings. By tuning the Fermi level of the graphene sheets, we can modulate the round-trip ring loss so that the transparency window can be dynamically tuned. The results provide a new method for the manipulation and transmission of light in highly integrated optical circuits and quantum information storage devices.

  10. Tunable optical analog to electromagnetically induced transparency in graphene-ring resonators system

    PubMed Central

    Wang, Yonghua; Xue, Chenyang; Zhang, Zengxing; Zheng, Hua; Zhang, Wendong; Yan, Shubin

    2016-01-01

    The analogue of electromagnetically induced transparency in optical ways has shown great potential in optical delay and quantum-information technology due to its flexible design and easy implementation. The chief drawback for these devices is the bad tunability. Here we demonstrate a tunable optical transparency system formed by graphene-silicon microrings which could control the transparent window by electro-optical means. The device consists of cascaded coupled ring resonators and a graphene/graphene capacitor which integrated on one of the rings. By tuning the Fermi level of the graphene sheets, we can modulate the round-trip ring loss so that the transparency window can be dynamically tuned. The results provide a new method for the manipulation and transmission of light in highly integrated optical circuits and quantum information storage devices. PMID:27941895

  11. Tuning all-Optical Analog to Electromagnetically Induced Transparency in nanobeam cavities using nanoelectromechanical system.

    PubMed

    Shi, Peng; Zhou, Guangya; Deng, Jie; Tian, Feng; Chau, Fook Siong

    2015-09-29

    We report the observations of all-optical electromagnetically induced transparency in nanostructures using waveguide side-coupled with photonic crystal nanobeam cavities, which has measured linewidths much narrower than individual resonances. The quality factor of transparency resonance can be 30 times larger than those of measured individual resonances. When the gap between cavity and waveguide is reduced to 10 nm, the bandwidth of destructive interference region can reach 10 nm while the width of transparency resonance is 0.3 nm. Subsequently, a comb-drive actuator is introduced to tune the line shape of the transparency resonance. The width of the peak is reduced to 15 pm and the resulting quality factor exceeds 10(5).

  12. Nickel nanowires mesh fabricated by ion beam irradiation-induced nanoscale welding for transparent conducting electrodes

    NASA Astrophysics Data System (ADS)

    Honey, S.; Ahmad, I.; Madhuku, M.; Naseem, S.; Maaza, M.; Kennedy, J. V.

    2017-07-01

    In this report, random nickel nanowires (Ni-NWs) meshes are fabricated by ions beam irradiation-induced nanoscale welding of NWs on intersecting positions. Ni-NWs are exposed to beam of 50 KeV Argon (Ar+) ions at various fluencies in the range ~1015 ions cm-2 to 1016 ions cm-2 at room temperature. Ni-NWs are welded due to accumulation of Ar+ ions beam irradiation-induced sputtered atoms on crossing positions. Ar+ ions irradiated Ni-NWs meshes are optically transparent and optical transparency is enhanced with increase in beam fluence of Ar+ ions. Ar+ ions beam irradiation-induced welded and optically transparent mesh is then exposed to 2.75 MeV hydrogen (H+) ions at fluencies 1  ×  1015 ions cm-2, 3  ×  1015 ions cm-2 and 1  ×  1016 ions cm-2 at room temperature. MeV H+ ions irradiation-induced local heat cause melting and fusion of NWs on intersecting points and eventually lead to reduce contact resistance between Ni-NWs. Electrical conductivity is enhanced with increase in beam fluence of H+ ions. These welded highly transparent and electrically conductive Ni-NWs meshes can be employed as transparent conducting electrodes in optoelectronic devices.

  13. On-chip plasmon-induced transparency based on plasmonic coupled nanocavities

    NASA Astrophysics Data System (ADS)

    Zhu, Yu; Hu, Xiaoyong; Yang, Hong; Gong, Qihuang

    2014-01-01

    On-chip plasmon-induced transparency offers the possibility of realization of ultrahigh-speed information processing chips. Unfortunately, little experimental progress has been made to date because it is difficult to obtain on-chip plasmon-induced transparency using only a single meta-molecule in plasmonic circuits. Here, we report a simple and efficient strategy to realize on-chip plasmon-induced transparency in a nanoscale U-shaped plasmonic waveguide side-coupled nanocavity pair. High tunability in the transparency window is achieved by covering the pair with different organic polymer layers. It is possible to realize ultrafast all-optical tunability based on pump light-induced refractive index change of a graphene cover layer. Compared with previous reports, the overall feature size of the plasmonic nanostructure is reduced by more than three orders of magnitude, while ultrahigh tunability of the transparency window is maintained. This work also provides a superior platform for the study of the various physical effects and phenomena of nonlinear optics and quantum optics.

  14. On-chip plasmon-induced transparency based on plasmonic coupled nanocavities.

    PubMed

    Zhu, Yu; Hu, Xiaoyong; Yang, Hong; Gong, Qihuang

    2014-01-17

    On-chip plasmon-induced transparency offers the possibility of realization of ultrahigh-speed information processing chips. Unfortunately, little experimental progress has been made to date because it is difficult to obtain on-chip plasmon-induced transparency using only a single meta-molecule in plasmonic circuits. Here, we report a simple and efficient strategy to realize on-chip plasmon-induced transparency in a nanoscale U-shaped plasmonic waveguide side-coupled nanocavity pair. High tunability in the transparency window is achieved by covering the pair with different organic polymer layers. It is possible to realize ultrafast all-optical tunability based on pump light-induced refractive index change of a graphene cover layer. Compared with previous reports, the overall feature size of the plasmonic nanostructure is reduced by more than three orders of magnitude, while ultrahigh tunability of the transparency window is maintained. This work also provides a superior platform for the study of the various physical effects and phenomena of nonlinear optics and quantum optics.

  15. On-chip plasmon-induced transparency based on plasmonic coupled nanocavities

    PubMed Central

    Zhu, Yu; Hu, Xiaoyong; Yang, Hong; Gong, Qihuang

    2014-01-01

    On-chip plasmon-induced transparency offers the possibility of realization of ultrahigh-speed information processing chips. Unfortunately, little experimental progress has been made to date because it is difficult to obtain on-chip plasmon-induced transparency using only a single meta-molecule in plasmonic circuits. Here, we report a simple and efficient strategy to realize on-chip plasmon-induced transparency in a nanoscale U-shaped plasmonic waveguide side-coupled nanocavity pair. High tunability in the transparency window is achieved by covering the pair with different organic polymer layers. It is possible to realize ultrafast all-optical tunability based on pump light-induced refractive index change of a graphene cover layer. Compared with previous reports, the overall feature size of the plasmonic nanostructure is reduced by more than three orders of magnitude, while ultrahigh tunability of the transparency window is maintained. This work also provides a superior platform for the study of the various physical effects and phenomena of nonlinear optics and quantum optics. PMID:24435059

  16. Dual coupled-resonator system for plasmon-induced transparency and slow light effect

    NASA Astrophysics Data System (ADS)

    Wang, Qinghao; Meng, Hongyun; Huang, Ben; Wang, Huihao; Zhang, Xing; Yu, Wei; Tan, Chunhua; Huang, Xuguang; Li, Shuti

    2016-12-01

    We proposed a dual coupled-resonator system based on the metal-insulator-metal bus waveguide and numerically investigated the plasmon-induced transparency and slow light effect with the Finite-Difference Time-Domain simulations in this paper. The electromagnetically induced transparency-like spectral response will occur between two adjacent stub resonators with detuned resonant wavelength due to the phase-coupled effect. The transmissivity and group index equations were been deduced, which indicated that the system can achieve the effect of the multiple electromagnetically induced transparency-like and slow light. With the optimization, the single peak transmission can reach to as high as 92%, dual PIT transmission peaks appear, as well as group index can reach over 75. These characteristics indicate multiple applications of our system in integrated optical circuits.

  17. Quantum-dot-induced transparency in a nanoscale plasmonic resonator.

    PubMed

    Wu, Xiaohua; Gray, Stephen K; Pelton, Matthew

    2010-11-08

    We investigate the near-field optical coupling between a single semiconductor nanocrystal (quantum dot) and a nanometer-scale plasmonic metal resonator using rigorous electrodynamic simulations. Our calculations show that the quantum dot produces a dip in both the extinction and scattering spectra of the surface-plasmon resonator, with a particularly strong change for the scattering spectrum. A phenomenological coupled-oscillator model is used to fit the calculation results and provide physical insight, revealing the roles of Fano interference and hybridization. The results indicate that it is possible to achieve nearly complete transparency as well as enter the strong-coupling regime for a single quantum dot in the near field of a metal nanostructure.

  18. Interference-induced angle-independent acoustical transparency

    SciTech Connect

    Qi, Lehua; Yu, Gaokun Wang, Ning; Wang, Xinlong; Wang, Guibo

    2014-12-21

    It is revealed that the Fano-like interference leads to the extraordinary acoustic transmission through a slab metamaterial of thickness much smaller than the wavelength, with each unit cell consisting of a Helmholtz resonator and a narrow subwavelength slit. More importantly, both the theoretical analysis and experimental measurement show that the angle-independent acoustical transparency can be realized by grafting a Helmholtz resonator and a quarter-wave resonator to the wall of a narrow subwavelength slit in each unit cell of a slit array. The observed phenomenon results from the interferences between the waves propagating in the slit, those re-radiated by the Helmholtz resonator, and those re-radiated by the quarter-wave resonator. The proposed design may find its applications in designing angle-independent acoustical filters and controlling the phase of the transmitted waves.

  19. Counterion-induced reversibly switchable transparency in smart windows.

    PubMed

    Lee, Chang Hwan; Lim, Ho Sun; Kim, Jooyong; Cho, Jeong Ho

    2011-09-27

    Smart windows that can reversibly alternate between extreme optical characteristics via clicking counteranions of different hydration energies were developed on glass substrates through the facile spray-casting of poly[2-(methacryloyloxy)ethyltrimethylammonium chloride-co-3-(trimethoxysilyl)propyl methacrylate]. The optical transmittance was either 90.9% or 0% over the whole spectral range when alternately immersed in solutions containing thiocyanate (SCN(-)) or bis(trifluoromethane)sulfonimide (TFSI(-)) ions, respectively. The extreme optical transitions were attributed to formation of microporous structures via the molecular aggregation of polyelectrolyte chains bearing TFSI(-) ions in methanol. Because the smart windows were either highly transparent toward or completely blocking of incident light upon direct counterion exchange, this kind of nanotechnology may provide a new platform for efficiently conserving on energy usage in the interior of buildings. © 2011 American Chemical Society

  20. Plasmonically induced transparent magnetic resonance in a metallic metamaterial composed of asymmetric double bars.

    PubMed

    Dong, Zheng-Gao; Liu, Hui; Xu, Ming-Xiang; Li, Tao; Wang, Shu-Ming; Zhu, Shi-Ning; Zhang, X

    2010-08-16

    We demonstrate that the trapped magnetic resonance mode can be induced in an asymmetric double-bar structure for electromagnetic waves normally incident onto the double-bar plane, which mode otherwise cannot be excited if the double bars are equal in length. By adjusting the structural geometry, the trapped magnetic resonance becomes transparent with little resonance absorption when it happens in the dipolar resonance regime, a phenomenon so-called plasmonic analogue of electromagnetically induced transparency (EIT). This planar EIT-like metamaterial offers a great geometry simplification by combining the radiant and subradiant resonant modes in a single double-bar resonator.

  1. Vector cavity optomechanics in the parameter configuration of optomechanically induced transparency

    NASA Astrophysics Data System (ADS)

    Xiong, Hao; Huang, Ya-Min; Wan, Liang-Liang; Wu, Ying

    2016-07-01

    We propose the concept of vector cavity optomechanics in which the polarization behavior of light fields is introduced to achieve optomechanical control. The steady states and optomechanically induced transparency are studied in the vector regime, and we show that the polarization of optical fields may be a powerful tool to identify the underlying physical process and control the signal of optomechanically induced transparency. In particular, the conditions for obtaining a linearly polarized output probe field is given, which reveal some nontrivial polarizing effects. Despite its conceptual simplicity, vector cavity optomechanics may entail a wide range of intriguing phenomena and uncover a novel understanding for optomechanical interaction.

  2. Plasmonic analog of electromagnetically-induced transparency of asymmetrical slots waveguide

    NASA Astrophysics Data System (ADS)

    Sun, Lin; Wang, Jicheng; Hu, Zheng-Da; Wang, Xiaosai; Chen, Jing

    2016-02-01

    In this paper, electromagnetically-induced transparency (EIT) phenomena have been investigated numerically in the plasmonic waveguides composed of unsymmetrical slot shaped metal-insulator-metal (MIM) structures. By the transmission line theory and Fabry-Perot model, the formation and evolution mechanisms of plasmon-induced transparency were exactly analyzed. The analysis showed that the peak of EIT-like transmission could be changed easily according to certain rules by adjusting the geometrical parameters of the slot structures, including the coupling distances and slot depths. We can find a new method to design nanoscale optical switch, devices in optical storage and optical computing.

  3. Cold denaturation induces inversion of dipole and spin transfer in chiral peptide monolayers

    NASA Astrophysics Data System (ADS)

    Eckshtain-Levi, Meital; Capua, Eyal; Refaely-Abramson, Sivan; Sarkar, Soumyajit; Gavrilov, Yulian; Mathew, Shinto P.; Paltiel, Yossi; Levy, Yaakov; Kronik, Leeor; Naaman, Ron

    2016-02-01

    Chirality-induced spin selectivity is a recently-discovered effect, which results in spin selectivity for electrons transmitted through chiral peptide monolayers. Here, we use this spin selectivity to probe the organization of self-assembled α-helix peptide monolayers and examine the relation between structural and spin transfer phenomena. We show that the α-helix structure of oligopeptides based on alanine and aminoisobutyric acid is transformed to a more linear one upon cooling. This process is similar to the known cold denaturation in peptides, but here the self-assembled monolayer plays the role of the solvent. The structural change results in a flip in the direction of the electrical dipole moment of the adsorbed molecules. The dipole flip is accompanied by a concomitant change in the spin that is preferred in electron transfer through the molecules, observed via a new solid-state hybrid organic-inorganic device that is based on the Hall effect, but operates with no external magnetic field or magnetic material.

  4. Cold denaturation induces inversion of dipole and spin transfer in chiral peptide monolayers.

    PubMed

    Eckshtain-Levi, Meital; Capua, Eyal; Refaely-Abramson, Sivan; Sarkar, Soumyajit; Gavrilov, Yulian; Mathew, Shinto P; Paltiel, Yossi; Levy, Yaakov; Kronik, Leeor; Naaman, Ron

    2016-02-26

    Chirality-induced spin selectivity is a recently-discovered effect, which results in spin selectivity for electrons transmitted through chiral peptide monolayers. Here, we use this spin selectivity to probe the organization of self-assembled α-helix peptide monolayers and examine the relation between structural and spin transfer phenomena. We show that the α-helix structure of oligopeptides based on alanine and aminoisobutyric acid is transformed to a more linear one upon cooling. This process is similar to the known cold denaturation in peptides, but here the self-assembled monolayer plays the role of the solvent. The structural change results in a flip in the direction of the electrical dipole moment of the adsorbed molecules. The dipole flip is accompanied by a concomitant change in the spin that is preferred in electron transfer through the molecules, observed via a new solid-state hybrid organic-inorganic device that is based on the Hall effect, but operates with no external magnetic field or magnetic material.

  5. Cold denaturation induces inversion of dipole and spin transfer in chiral peptide monolayers

    PubMed Central

    Eckshtain-Levi, Meital; Capua, Eyal; Refaely-Abramson, Sivan; Sarkar, Soumyajit; Gavrilov, Yulian; Mathew, Shinto P.; Paltiel, Yossi; Levy, Yaakov; Kronik, Leeor; Naaman, Ron

    2016-01-01

    Chirality-induced spin selectivity is a recently-discovered effect, which results in spin selectivity for electrons transmitted through chiral peptide monolayers. Here, we use this spin selectivity to probe the organization of self-assembled α-helix peptide monolayers and examine the relation between structural and spin transfer phenomena. We show that the α-helix structure of oligopeptides based on alanine and aminoisobutyric acid is transformed to a more linear one upon cooling. This process is similar to the known cold denaturation in peptides, but here the self-assembled monolayer plays the role of the solvent. The structural change results in a flip in the direction of the electrical dipole moment of the adsorbed molecules. The dipole flip is accompanied by a concomitant change in the spin that is preferred in electron transfer through the molecules, observed via a new solid-state hybrid organic–inorganic device that is based on the Hall effect, but operates with no external magnetic field or magnetic material. PMID:26916536

  6. Dipole-induced band-gap reduction in an inorganic cage.

    PubMed

    Lv, Yaokang; Cheng, Jun; Steiner, Alexander; Gan, Lihua; Wright, Dominic S

    2014-02-10

    Metal-doped polyoxotitanium cages are a developing class of inorganic compounds which can be regarded as nano- and sub-nano sized molecular relatives of metal-doped titania nanoparticles. These species can serve as models for the ways in which dopant metal ions can be incorporated into metal-doped titania (TiO2 ), a technologically important class of photocatalytic materials with broad applications in devices and pollution control. In this study a series of cobalt(II)-containing cages in the size range ca. 0.7-1.3 nm have been synthesized and structurally characterized, allowing a coherent study of the factors affecting the band gaps in well-defined metal-doped model systems. Band structure calculations are consistent with experimental UV/Vis measurements of the Tix Oy absorption edges in these species and reveal that molecular dipole moment can have a profound effect on the band gap. The observation of a dipole-induced band-gap decrease mechanism provides a potentially general design strategy for the formation of low band-gap inorganic cages.

  7. Light-induced dipole moment modulation in diarylethenes: a fundamental study.

    PubMed

    Bianco, Andrea; Ferrari, Giorgio; Castagna, Rossella; Rossi, Andrea; Carminati, Marco; Pariani, Giorgio; Tommasini, Matteo; Bertarelli, Chiara

    2016-11-16

    The dipole moment of photochromic diarylethenes is determined in solution for both the coloured and uncoloured forms by measuring the capacitance of a capacitor filled with a photochromic solution as a dielectric material. Diarylethenes with different substituents are investigated and the modulation of the dipole moment is related to their chemical structures. We determine a modulation of the dipole moment up to 4 Debye. We discuss the model used to obtain the dipole moment from the capacitance measurements and we compare the experimental results with the outcomes from DFT calculations. The results highlight the importance of conformational effects in the description of the dipole moment of diarylethenes.

  8. Plasmon-induced multilevel-transparency in two-dimensional hybrid coplanar waveguide

    NASA Astrophysics Data System (ADS)

    Shang, Xiong-Jun; Wang, Ling-Ling; Zhai, Xiang; Yue, Jing; Luo, Xin; Duan, Hui-Gao

    2016-09-01

    The optical transmission property of a hybrid coplanar waveguide consisting of three quarters of a nanoring (TQNR) and a slot cavity resonator is numerically investigated and theoretically analyzed. In this paper, the apparent multilevel plasmon-induced transparency (PIT) effect can be obtained due to the interaction between the resonance modes of the two elements. Combining the calculated magnetic field distribution with the theoretically fitted parameters, the transparency windows of all resonance modes can be clearly investigated. The results show that the second-order transparency window originates from the destructive interference between the bright and dark mode of the hybrid system, while the first- and third-order transparency windows originate from the suppression effect of the dark mode. As the assessment standard for application, the maximal values of \\text{FO}{{\\text{M}}\\ast} appear at the transmission dips and their highest reaches to near 18. While the \\text{FOM} reaches to an impressive value 270 at the third-order transparent window, and the sensitivity is as high as 2650 nm RIU-1 at the first-order transparent window. This research provides a guide to the practical applications in the visible and near-infrared light region.

  9. Effects of electric field and structure on the electromagnetically induced transparency in double quantum dot

    NASA Astrophysics Data System (ADS)

    Bejan, D.

    2017-05-01

    We theoretically investigated the effects of electric field and structural parameters of the confining potential on the optical properties of a GaAs/AlGaAs double quantum dot related to the occurrence of the electromagnetically induced transparency phenomenon, using the compact density-matrix formalism and the effective mass approximation. The dependences of the absorption coefficient, refraction index and light group velocity on the Rabi frequency of the control field, intensity of the static electric field, asymmetry parameter of the potential and dot dimension are discussed in detail. It is found that electromagnetically induced transparency occurs in the system for intermediate field values and its transparency window for probe field absorption and sub- and super-luminal frequency interval of the probe field are blueshifted by the increment of the electric field strength and dot dimension but are redshifted by the augment of the asymmetry parameter of the potential.

  10. Terahertz radiation-induced sub-cycle field electron emission across a split-gap dipole antenna

    SciTech Connect

    Zhang, Jingdi; Averitt, Richard D. E-mail: raveritt@ucsd.edu; Zhao, Xiaoguang; Fan, Kebin; Wang, Xiaoning; Zhang, Xin E-mail: raveritt@ucsd.edu; Zhang, Gu-Feng; Geng, Kun

    2015-12-07

    We use intense terahertz pulses to excite the resonant mode (0.6 THz) of a micro-fabricated dipole antenna with a vacuum gap. The dipole antenna structure enhances the peak amplitude of the in-gap THz electric field by a factor of ∼170. Above an in-gap E-field threshold amplitude of ∼10 MV/cm{sup −1}, THz-induced field electron emission is observed as indicated by the field-induced electric current across the dipole antenna gap. Field emission occurs within a fraction of the driving THz period. Our analysis of the current (I) and incident electric field (E) is in agreement with a Millikan-Lauritsen analysis where log (I) exhibits a linear dependence on 1/E. Numerical estimates indicate that the electrons are accelerated to a value of approximately one tenth of the speed of light.

  11. Terahertz radiation-induced sub-cycle field electron emission across a split-gap dipole antenna

    NASA Astrophysics Data System (ADS)

    Zhang, Jingdi; Zhao, Xiaoguang; Fan, Kebin; Wang, Xiaoning; Zhang, Gu-Feng; Geng, Kun; Zhang, Xin; Averitt, Richard D.

    2015-12-01

    We use intense terahertz pulses to excite the resonant mode (0.6 THz) of a micro-fabricated dipole antenna with a vacuum gap. The dipole antenna structure enhances the peak amplitude of the in-gap THz electric field by a factor of ˜170. Above an in-gap E-field threshold amplitude of ˜10 MV/cm-1, THz-induced field electron emission is observed as indicated by the field-induced electric current across the dipole antenna gap. Field emission occurs within a fraction of the driving THz period. Our analysis of the current (I) and incident electric field (E) is in agreement with a Millikan-Lauritsen analysis where log (I) exhibits a linear dependence on 1/E. Numerical estimates indicate that the electrons are accelerated to a value of approximately one tenth of the speed of light.

  12. Electric dipole moment induced by CP-violating deformations in the noncommutative Standard Model

    NASA Astrophysics Data System (ADS)

    Wang, Wei-Jian; Yan, Zhe-Hui; Guan, Rong-Hua; Wei, Xing-Ning

    2017-03-01

    The possibility to detect the noncommutative (NC) spacetime in the electric dipole moments (EDM) experiments is studied in the effective field theory of noncommutative Standard Model (NCSM) with many additional deformations. The EDM given by the previous literatures do not have any observable effect since they are spin-independent. In this work, it is found that three of the deformed terms provide extra sources of CP violation contributed to EDM. We show that these EDMs are sensitive to the spin and thus have potential to be measured in the highly precise experiments. In particular, the EDM induced by NC spacetime may not be parallel to the direction of spin, which demonstrates the intrinsic feature of NC field theory.

  13. Plasmonic induced transparency in a coupled system composed of metal-insulate-metal stub and trapezoid cavity resonator

    NASA Astrophysics Data System (ADS)

    Zheng, Pengfei; Yang, Huimin; Jiao, Linsen; Fan, Meiyong; Yun, Binfeng; Cui, Yiping

    2017-08-01

    A plasmonic induced transparency system constructed by a metal-insulate-metal stub coupled with a trapezoid cavity resonator was proposed. The results show that the spectra of different narrow modes in the trapezoid resonator can overlap with the broad stub mode and induce the plasmonic induced transparency effect. However, some of them cannot produce a plasmonic induced transparency effect because there is hardly any near field overlap between the trapezoid cavity mode and the stub mode, which was proved by the mode field distributions in the coupled resonator system. The ;disappeared; plasmonic induced transparency can be reproduced by changing the relative position between the stub and trapezoid resonator. Also the coupling strength can be modulated by this method to manipulate the plasmonic induced transparency and slow light effect.

  14. Experimental distinction of Autler-Townes splitting from electromagnetically induced transparency using coupled mechanical oscillators system

    PubMed Central

    Liu, Jingliang; Yang, Hujiang; Wang, Chuan; Xu, Kun; Xiao, Jinghua

    2016-01-01

    Here we experimentally demonstrated the electromagnetically induced transparency (EIT) and Autler-Townes splitting (ATS) effects in mechanical coupled pendulums. The analogue of EIT and ATS has been studied in mechanical systems and the intrinsic physics between these two phenomena are also been discussed. Exploiting the Akaike Information Criterion, we discern the ATS effect from EIT effect in our experimental results. PMID:26751738

  15. Electromagnetically induced transparency in a cascade-type quantum well subband system under intense picosecond excitation

    NASA Astrophysics Data System (ADS)

    Hanna, S.; Eichenberg, B.; Firsov, D. A.; Vorobjev, L. E.; Ustinov, V. M.; Seilmeier, A.

    2016-01-01

    The coherent light-matter interaction in a 4-level cascade-type subband system of an asymmetric GaAs/AlGaAs quantum well structure is studied in pump-probe transmission experiments with picosecond (ps) time resolution. Coupling two excited subbands by an intense mid-infrared laser pulse at low sample temperatures is found to result in a substantially increased transparency of the fundamental e1-e2 transition. We find a reduction of the absorption coefficient by ~80%, which is one of the most pronounced electromagnetically induced transparency in solid state systems observed so far.

  16. Tunable ultracompact chip-integrated multichannel filter based on plasmon-induced transparencies

    NASA Astrophysics Data System (ADS)

    Yang, Xiaoyu; Hu, Xiaoyong; Chai, Zhen; Lu, Cuicui; Yang, Hong; Gong, Qihuang

    2014-06-01

    Nanoscale multichannel filter is realized in plasmonic circuits directly, which consists of four plasmonic nanocavities coupled via a plasmonic waveguide etched in a gold film. The feature device size is only 1.35 μm, which is reduced by five orders of magnitude compared with previous reports. The optical channels are formed by transparency windows of plasmon-induced transparencies. A shift of 45 nm in the central wavelengths of optical channels is obtained when the plasmonic coupled-nanocavities are covered with a 100-nm-thick poly(methyl methacrylate) layer. This work opens up the possibility for the realization of solid quantum chips based on plasmonic circuits.

  17. Polarization-independent electromagnetically induced transparency-like transmission in coupled guided-mode resonance structures

    NASA Astrophysics Data System (ADS)

    Lee, Sun-Goo; Kim, Seong-Han; Kim, Kap-Joong; Kee, Chul-Sik

    2017-03-01

    We present two photonic systems that make it possible to realize polarization-independent electromagnetically induced transparency based on guided-mode resonances. Each system is composed of two planar dielectric waveguides and a two-dimensional photonic crystal. Using finite-difference time-domain simulations, we demonstrate that by coupling the two guided-mode resonances with low- and high-quality factors, a narrow transparency window is generated inside a broad background transmission dip produced by the guided-mode resonances. We also show that the time delay that occurs when light beams pass through the proposed systems can be controlled by adjusting the distance between the two waveguides.

  18. Mid-infrared plasmon induced transparency in heterogeneous graphene ribbon pairs.

    PubMed

    Wang, Lei; Cai, Wei; Luo, Weiwei; Ma, Zenghong; Du, Chenglin; Zhang, Xinzheng; Xu, Jingjun

    2014-12-29

    The control of coherent phenomena in graphene structures is proposed. Specifically, plasmon induced transparency (PIT) effect is investigated in a kind of simple graphene structures - graphene ribbon pairs. The transparency effect are understood by the mode coupling between dipolar and quadrupole plasmons modes in graphene ribbons. By using bias voltage tuning or geometry parameters changing, the PIT effect can be effectively controlled, which is based on the frequency tuning of dipolar or quadrupole modes in ribbons. These properties make these structures possess applications in two-dimensional plasmonics devices in mid-infrared range. In addition, the tuning of PIT in graphene ribbon pairs opens an avenue for active coherent control in plasmonics.

  19. Tunable terahertz plasmon-induced transparency with aperture-side-coupled disk resonators

    NASA Astrophysics Data System (ADS)

    Nozhat, Najmeh

    2017-05-01

    An analog of electromagnetically induced transparency (EIT) in plasmonic double disk resonators aperture-side-coupled to an InSb bus waveguide at the terahertz (THz) frequency region has been investigated. When there is a destructive interference coupling between these two disk resonators, the proposed plasmonic structure exhibits a transparency window. The simulation results show that the EIT-like response is dependent on the coupling distance between two disk resonators. Since the permittivity of InSb is modified by varying temperature, the central wavelength of the EIT-like transmission can be controlled by tuning the temperature. The proposed plasmonic structure may have applications in THz integrated circuits.

  20. Experimental investigation of self-induced transparency and pulse delay in ruby.

    NASA Technical Reports Server (NTRS)

    Asher, I. M.

    1972-01-01

    We have investigated the self-induced transparency effect in ruby over a range of input energies which range from linear absorption to full transparency. The transmission, pulse delay, and pulse broadening were studied as a function of input energy. The transition region is narrower than that found in similar studies of the CO2/SF6 system; this is consistent with predictions based on ensembles of two-level systems. Included are the first pulse-delay and pulse-broadening curves to be obtained for the ruby system.

  1. Enhancement of ferroelectric Curie temperature in BaTiO3 films via strain-induced defect dipole alignment.

    PubMed

    Damodaran, Anoop R; Breckenfeld, Eric; Chen, Zuhuang; Lee, Sungki; Martin, Lane W

    2014-09-01

    The combination of epitaxial strain and defect engineering facilitates the tuning of the transition temperature of BaTiO3 to >800 °C. Advances in thin-film deposition enable the utilization of both the electric and elastic dipoles of defects to extend the epitaxial strain to new levels, inducing unprecedented functionality and temperature stability in ferroelectrics.

  2. Spatial soliton pairs of the vectorial Thirring model realized in a coherent atomic system via electromagnetically induced transparency

    NASA Astrophysics Data System (ADS)

    Li, Hui-jun; Zhang, Kun

    2017-01-01

    We propose a scheme to realize a (2+1)-dimensional vectorial Thirring model in a coherent atomic system via electromagnetically induced transparency (EIT). We show that under EIT conditions the probe field envelopes obey coupled nonlinear Schrödinger equations, which are reduced to a Thirring model when system parameters are suitably chosen. We present spatial soliton-pair solutions exhibiting many interesting features, including controllability (i.e., the soliton property of one component can be adjusted by the propagation constant of another component in which the soliton remains unchanged), diversity (i.e., many different types of soliton-pair solutions can be found, including bright-bright, dark-bright, dark-dark, darklike-dark, dark-dipole, darklike-multidark, and high-dimensional bright-bright, dark-darklike soliton pairs), and stability. Furthermore, we demonstrate that the stability of soliton pairs in the system can be strengthened by adjusting the propagation constant. Comparing with previous studies, in addition to supporting much more stable (1+1)-dimensional and (2+1)-dimensional spatial soliton-pair solutions, the present scheme needs only a single atomic species and hence is easy to realize experimentally.

  3. Radiation-induced transient darkening of optically transparent polymers

    SciTech Connect

    Downey, S.W.; Builta, L.A.; Carlson, R.L.; Czuchlewski, S.J.; Moir, D.C.

    1986-11-15

    Results are presented for the radiation-induced transient darkening of thin organic polymer films normally used as Cerenkov light emissions sources. The radiation source is a 27-MeV, 10-..mu..C, 200-ns electron beam generated by the PHERMEX accelerator. The typical dose for a single pulse is 5 Mrad. At this dose, the broadband time-resolved percent transmission above 520 nm was measured for four common polymers: polyimide (Kapton-H), polyethylene terephthalate (Mylar), cellulose acetate, and high-density polyethylene. Kapton was found to darken the most and polyethylene darkened the least. The recovery time to normal transmission for Kapton was found to be greater than 10--20 ..mu..s. The radiation-induced attenuation coefficient is shown to depend on electronic band energy separation. The results show that Kapton is not the material of choice for a Cerenkov light source.

  4. Field-induced activation of metal oxide semiconductor for low temperature flexible transparent electronic device applications

    NASA Astrophysics Data System (ADS)

    Pudasaini, Pushpa Raj; Noh, Joo Hyon; Wong, Anthony; Haglund, Amada; Ward, Thomas Zac; Mandrus, David; Rack, Philip

    Amorphous metal-oxide semiconductors have been extensively studied as an active channel material in thin film transistors due to their high carrier mobility, and excellent large-area uniformity. Here, we report the athermal activation of amorphous indium gallium zinc oxide semiconductor channels by an electric field-induced oxygen migration via gating through an ionic liquid. Using field-induced activation, a transparent flexible thin film transistor is demonstrated on a polyamide substrate with transistor characteristics having a current ON-OFF ratio exceeding 108, and saturation field effect mobility of 8.32 cm2/(V.s) without a post-deposition thermal treatment. This study demonstrates the potential of field-induced activation as an athermal alternative to traditional post-deposition thermal annealing for metal oxide electronic devices suitable for transparent and flexible polymer substrates. Materials Science and Technology Division, ORBL, Oak Ridge, TN 37831, USA.

  5. Three-pathway electromagnetically induced transparency in coupled-cavity optomechanical system.

    PubMed

    Lei, Fu-Chuan; Gao, Ming; Du, Chunguang; Jing, Qing-Li; Long, Gui-Lu

    2015-05-04

    Recently Qu and Agarwal [Phys. Rev. A 22, 031802 (2013)] found a three-pathway electromagnetically induced absorption (TEIA) phenomenon within a mechanically coupled two-cavity system, where there exist a sharp EIA dip in the broad electromagnetically induced transparency peak in the transmission spectrum. In this work, we study the response of a probe light in a pair of directly coupled microcavities with one mechanical mode. We find that in addition to the sharp TEIA dip within a broad EIT window as found by Qu and Agarwal, three-pathway electromagnetically induced transparency (TEIT) within the broad EIT window could also exist under certain conditions. We give explicit physical explanations and detailed calculations. Our results provide a method for controlling transition between TEIA and TEIT in coupled optomechanical systems, and reveal the multiple pathways interference is versatile for controlling light.

  6. Far-infrared permanent and induced dipole absorption of diatomic molecules in rare-gas fluids. I. Spectral theory

    NASA Astrophysics Data System (ADS)

    Roco, J. M. M.; Hernández, A. Calvo; Velasco, S.

    1995-12-01

    We present a spectral theory for the far-infrared absorption spectrum of a very diluted solution of diatomic molecules in a rare-gas fluid, that includes permanent and induced contributions. The absorption coefficient is given as the convolution of a translational spectrum and a rotational spectrum. The former is described in terms of time correlation functions associated to the induced dipole moment. The latter is discussed on the basis of a model consisting of a quantum rigid rotor interacting with a thermal bath, making use of time correlation functions associated to the different anisotropic orders of the solute-solvent intermolecular potential. Non-Markovian and line mixing effects are taken into account. Explicit expressions for the five leading contributions of the induced dipole moment are given.

  7. Coupled wave analysis of holographically induced transparency (HIT) generated by two multiplexed volume gratings.

    PubMed

    Carretero, Luis; Blaya, Salvador; Acebal, Pablo; Fimia, Antonio; Madrigal, Roque; Murciano, Angel

    2011-04-11

    We present a holographic system that can be used to manipulate the group velocity of light pulses. The proposed structure is based on the multiplexing of two sequential holographic volume gratings, one in transmission and the other in reflection geometry, where one of the recording beams must be the same for both structures. As in other systems such as grating induced transparency (GIT) or coupled-resonator-induced transparency (CRIT), by using the coupled wave theory it is shown that this holographic structure represents a classical analogue of the electromagnetically induced transparency (EIT). Analytical expressions were obtained for the transmittance induced at the forbidden band (spectral hole) and conditions where the group velocity was slowed down were analyzed. Moreover, the propagation of Gaussian pulses is analyzed for this system by obtaining, after further approximations, analytical expressions for the distortion of the transmitted field. As a result, we demonstrate the conditions where the transmitted pulse is slowed down and its shape is only slightly distorted. Finally, by comparing with the exact solutions obtained, the range of validity of all the analytical formulae was verified, demonstrating that the error is very low.

  8. AC electric field induced dipole-based on-chip 3D cell rotation.

    PubMed

    Benhal, Prateek; Chase, J Geoffrey; Gaynor, Paul; Oback, Björn; Wang, Wenhui

    2014-08-07

    The precise rotation of suspended cells is one of the many fundamental manipulations used in a wide range of biotechnological applications such as cell injection and enucleation in nuclear transfer (NT) cloning. Noticeably scarce among the existing rotation techniques is the three-dimensional (3D) rotation of cells on a single chip. Here we present an alternating current (ac) induced electric field-based biochip platform, which has an open-top sub-mm square chamber enclosed by four sidewall electrodes and two bottom electrodes, to achieve rotation about the two axes, thus 3D cell rotation. By applying an ac potential to the four sidewall electrodes, an in-plane (yaw) rotating electric field is generated and in-plane rotation is achieved. Similarly, by applying an ac potential to two opposite sidewall electrodes and the two bottom electrodes, an out-of-plane (pitch) rotating electric field is generated and rolling rotation is achieved. As a prompt proof-of-concept, bottom electrodes were constructed with transparent indium tin oxide (ITO) using the standard lift-off process and the sidewall electrodes were constructed using a low-cost micro-milling process and then assembled to form the chip. Through experiments, we demonstrate rotation of bovine oocytes of ~120 μm diameter about two axes, with the capability of controlling the rotation direction and the rate for each axis through control of the ac potential amplitude, frequency, and phase shift, and cell medium conductivity. The maximum observed rotation rate reached nearly 140° s⁻¹, while a consistent rotation rate reached up to 40° s⁻¹. Rotation rate spectra for zona pellucida-intact and zona pellucida-free oocytes were further compared and found to have no effective difference. This simple, transparent, cheap-to-manufacture, and open-top platform allows additional functional modules to be integrated to become a more powerful cell manipulation system.

  9. Optical Analog to Electromagnetically Induced Transparency in Cascaded Ring-Resonator Systems

    PubMed Central

    Wang, Yonghua; Zheng, Hua; Xue, Chenyang; Zhang, Wendong

    2016-01-01

    The analogue of electromagnetically induced transparency in optical methods has shown great potential in slow light and sensing applications. Here, we experimentally demonstrated a coupled resonator induced transparency system with three cascaded ring coupled resonators in a silicon chip. The structure was modeled by using the transfer matrix method. Influences of various parameters including coupling ratio of couplers, waveguide loss and additional loss of couplers on transmission characteristic and group index have been investigated theoretically and numerically in detail. The transmission character of the system was measured by the vertical grating coupling method. The enhanced quality factor reached 1.22 × 105. In addition, we further test the temperature performance of the device. The results provide a new method for the manipulation of light in highly integrated optical circuits and sensing applications. PMID:27463720

  10. Plasmonic electromagnetically induced transparency in metallic nanoparticle-quantum dot hybrid systems

    NASA Astrophysics Data System (ADS)

    Hatef, Ali; Sadeghi, Seyed M.; Singh, Mahi R.

    2012-02-01

    We study the variation of the energy absorption rate in a hybrid semiconductor quantum dot-metallic nanoparticle system doped in a photonic crystal. The quantum dot is taken as a three-level V-configuration system and is driven by two applied fields (probe and control). We consider that one of the excitonic resonance frequencies is near to the plasmonic resonance frequency of the metallic nanoparticle, and is driven by the probe field. The other excitonic resonance frequency is far from both the plasmonic resonance frequency and the photonic bandgap edge, and is driven by the control field. In the absence of the photonic crystal we found that the system supports three excitonic-induced transparencies in the energy absorption spectrum of the metallic nanoparticle. We show that the photonic crystal allows us to manipulate the frequencies of such excitonic-induced transparencies and the amplitude of the energy absorption rate.

  11. Brillouin-scattering-induced transparency and non-reciprocal light storage

    PubMed Central

    Dong, Chun-Hua; Shen, Zhen; Zou, Chang-Ling; Zhang, Yan-Lei; Fu, Wei; Guo, Guang-Can

    2015-01-01

    Stimulated Brillouin scattering is a fundamental interaction between light and travelling acoustic waves and arises primarily from electrostriction and photoelastic effects, with an interaction strength several orders of magnitude greater than that of other relevant non-linear optical processes. Here we report an experimental demonstration of Brillouin-scattering-induced transparency in a high-quality whispering-gallery-mode optical microresonantor. The triply resonant Stimulated Brillouin scattering process underlying the Brillouin-scattering-induced transparency greatly enhances the light–acoustic interaction, enabling the storage of light as a coherent, circulating acoustic wave with a lifetime up to 10 μs. Furthermore, because of the phase-matching requirement, a circulating acoustic wave can only couple to light with a given propagation direction, leading to non-reciprocal light storage and retrieval. These unique features establish a new avenue towards integrated all-optical switching with low-power consumption, optical isolators and circulators. PMID:25648234

  12. Low-loss metamaterial electromagnetically induced transparency based on electric toroidal dipolar response

    SciTech Connect

    Li, Hai-ming; Liu, Shao-bin Liu, Si-yuan; Ding, Guo-wen; Yang, Hua; Yu, Zhi-yang; Zhang, Hai-feng; Wang, Shen-yun

    2015-02-23

    In this paper, a low-loss and high transmission analogy of electromagnetically induced transparency based on electric toroidal dipolar response is numerically and experimentally demonstrated. It is obtained by the excitation of the low-loss electric toroidal dipolar response, which confines the magnetic field inside a dielectric substrate with toroidal geometry. The metamaterial electromagnetically induced transparency (EIT) structure is composed of the cut wire and asymmetric split-ring resonators. The transmission level is as high as 0.88, and the radiation loss is greatly suppressed, which can be proved by the surface currents distributions, the magnetic field distributions, and the imaginary parts of the effective permeability and permittivity. It offers an effective way to produce low-loss and high transmission metamaterial EIT.

  13. Tip-bias-induced domain evolution in PMN-PT transparent ceramics via piezoresponse force microscopy

    NASA Astrophysics Data System (ADS)

    Zhao, K. Y.; Zhao, W.; Zeng, H. R.; Yu, H. Z.; Ruan, W.; Xu, K. Q.; Li, G. R.

    2015-05-01

    Piezoresponse force microscopy (PFM) was employed to investigate ferroelectric domain structures and their dynamic behavior of lead magnesium niobate-lead titanate [Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-PT)] transparent ceramics under an tip-bias-induced electric field. A remarkable effect of fluctuation of PT content on the domain configurations and domain dynamic response in PMN-PT transparent ferroelectric ceramics were found by PFM. Comparing with PMN-10%PT and PMN-20%PT, the reversed polarization of macrodomain area in PMN-35%PT and PMN-25%PT exhibits a relatively higher response behavior and better polarization retention performance under the PFM tip-bias-induced electric field, which correspond to their unique macroscopic electro-optic properties.

  14. Giant Kerr nonlinearity and low-power gigahertz solitons via plasmon-induced transparency.

    PubMed

    Bai, Zhengyang; Huang, Guoxiang; Liu, Lixiang; Zhang, Shuang

    2015-09-08

    We propose a method to enhance Kerr nonlinearity and realize low-power gigahertz solitons via plasmon-induced transparency (PIT) in a new type of metamaterial, which is constructed by an array of unit cell consisting of a cut-wire and a pair of varactor-loaded split-ring resonators. We show that the PIT in such metamaterial can not only mimic the electromagnetically induced transparency in coherent three-level atomic systems, but also exhibit a crossover from PIT to Autler-Townes splitting. We further show that the system suggested here also possess a giant third-order nonlinear susceptibility and may be used to create solitons with extremely low generation power. Our study raises the possibility for obtaining strong nonlinear effect of gigahertz radiation at very low intensity based on room-temperature metamaterials.

  15. Optical Analog to Electromagnetically Induced Transparency in Cascaded Ring-Resonator Systems.

    PubMed

    Wang, Yonghua; Zheng, Hua; Xue, Chenyang; Zhang, Wendong

    2016-07-25

    The analogue of electromagnetically induced transparency in optical methods has shown great potential in slow light and sensing applications. Here, we experimentally demonstrated a coupled resonator induced transparency system with three cascaded ring coupled resonators in a silicon chip. The structure was modeled by using the transfer matrix method. Influences of various parameters including coupling ratio of couplers, waveguide loss and additional loss of couplers on transmission characteristic and group index have been investigated theoretically and numerically in detail. The transmission character of the system was measured by the vertical grating coupling method. The enhanced quality factor reached 1.22 × 10⁵. In addition, we further test the temperature performance of the device. The results provide a new method for the manipulation of light in highly integrated optical circuits and sensing applications.

  16. Pulsed-induced electromagnetically induced transparency in the acetylene-filled hollow-core fibers

    NASA Astrophysics Data System (ADS)

    Rodríguez, Nayeli Casillas; Stepanov, Serguei; Miramontes, Manuel Ocegueda; Hernández, Eliseo Hernández

    2017-06-01

    Experimental results on pulsed excitation of electromagnetically induced transparency (EIT) in the acetylene-filled hollow-core photonic crystal fiber (HC-PCF) at pressures 0.1-0.4 Torr are reported. The EIT was observed both in Λ and V interaction configurations with the continuous probe wave tuned to R9 (1520.08 nm) acetylene absorption line and with the control pulses tuned to P11 (1531.58 nm) and P9 (1530.37 nm) lines, respectively. The utilized control pulses were of up to 40 ns duration with <2.5 ns fronts and with maximum input power 1 W. The maximum modulation depth of the initial probe wave absorption via EIT was up to 40 and 15% for the co- and counter-propagation of the probe and control waves, respectively, and importance of the waves polarization matching was demonstrated. For a qualitative explanation of reduction in the counter-propagation EIT efficiency a simple model of the accelerated mismatch of the two-frequency EIT resonance with deviation of the molecule thermal velocity from the resonance value was utilized. It was shown experimentally that the EIT efficiencies in both configurations do not depend on the longitudinal velocity of the molecules. The characteristic relaxation time of the of the EIT response was found to be about 9 ns, i.e., is close to the relaxation times T 1,2 of the acetylene molecules under the utilized experimental conditions.

  17. Hanle electromagnetically induced transparency and absorption resonances with a Laguerre Gaussian beam

    SciTech Connect

    Anupriya, J.; Ram, Nibedita; Pattabiraman, M.

    2010-04-15

    We describe a computational and experimental study on Hanle electromagnetically induced transparency and absorption resonance line shapes with a Laguerre Gaussian (LG) beam. It is seen that the LG beam profile brings about a significant narrowing in the line shape of the Hanle resonance and ground-state Zeeman coherence in comparison to a Gaussian beam. This narrowing is attributed to the azimuthal mode index of the LG field.

  18. Optomechanical electromagnetically induced transparency in inverted atomic configurations: a comparative view

    NASA Astrophysics Data System (ADS)

    Asghari Nejad, A.; Askari, H. R.; Baghshahi, H. R.

    2017-03-01

    We study electromagnetically induced transparency (EIT), which is affected by cavity optomechanics in different atomic configurations (V and Λ ). The cavity mode is depicted as a probe field, and a classical driving field is applied to the atomic medium as the control laser in each system. Interaction between the cavity mode, atomic media and the oscillating mirror of the cavity can change the susceptibility of the atomic ensemble. Equations of motion demonstrate a system of nonlinear equations for each system. Nonlinearity of equations is a result of interaction between the cavity mode and atomic transitions. The equations are solved via a perturbation method. The results show two different aspects of atom-assisted optomechanics in V-type system: a common transparency window and an amplifying process in a transparency window that does not occur in the Λ configuration, notable as a considerable difference between the proposed systems. It is shown that classical field detuning leads to different changes in the susceptibility of both systems; other values of cavity detuning, except in the resonant case, can guarantee the occurrence of EIT in the system. For the initial value of the cavity field, a negative region appears in absorption spectrum of the V-type atomic ensemble. Meanwhile, the Λ configuration does not show a such process. According to our results, in the appearance of the transparency window, the position of movable mirror changes significantly.

  19. Numerical simulation of adiabatons in electromagnetically induced transparency under quasi-resonance conditions

    SciTech Connect

    Parshkov, O M; Govorenko, E R

    2014-02-28

    The evolution of adiabatons in electromagnetically induced transparency in the Λ scheme of degenerate quantum transitions J = 0 → J = 1 → J = 2 with Doppler broadening of spectral lines has been numerically simulated taking into account the effect of resonance detunings. It is shown that, in the case of linearly polarised fields, an increase in the probe-field resonance detuning (under exact-resonance conditions for the control radiation) leads to a transformation of electromagnetically induced transparency into electromagnetically induced absorption at certain stages. When the control-field resonance detuning is varied, the transparency of the medium for the probe (exactly resonant) radiation monotonically decreases with increasing detuning because of the rising role of single-photon absorption. In the case of circularly polarised control radiation and linearly polarised input probe field, a probe pulse propagating in the medium splits into two pulses with oppositely directed circular polarisations. An increase in the probe pulse resonance detuning (under exact-resonance conditions for the control radiation) leads primarily to an increase in the absorption by the medium of the probe pulse, the direction of circular polarisation for which coincides with the circular-polarisation direction for the control radiation. (nonlinear optical phenomena)

  20. Topology of surfaces for molecular Stark energy, alignment, and orientation generated by combined permanent and induced electric dipole interactions

    SciTech Connect

    Schmidt, Burkhard; Friedrich, Bretislav

    2014-02-14

    We show that combined permanent and induced electric dipole interactions of linear polar and polarizable molecules with collinear electric fields lead to a sui generis topology of the corresponding Stark energy surfaces and of other observables – such as alignment and orientation cosines – in the plane spanned by the permanent and induced dipole interaction parameters. We find that the loci of the intersections of the surfaces can be traced analytically and that the eigenstates as well as the number of their intersections can be characterized by a single integer index. The value of the index, distinctive for a particular ratio of the interaction parameters, brings out a close kinship with the eigenproperties obtained previously for a class of Stark states via the apparatus of supersymmetric quantum mechanics.

  1. Topology of surfaces for molecular Stark energy, alignment, and orientation generated by combined permanent and induced electric dipole interactions

    NASA Astrophysics Data System (ADS)

    Schmidt, Burkhard; Friedrich, Bretislav

    2014-02-01

    We show that combined permanent and induced electric dipole interactions of linear polar and polarizable molecules with collinear electric fields lead to a sui generis topology of the corresponding Stark energy surfaces and of other observables - such as alignment and orientation cosines - in the plane spanned by the permanent and induced dipole interaction parameters. We find that the loci of the intersections of the surfaces can be traced analytically and that the eigenstates as well as the number of their intersections can be characterized by a single integer index. The value of the index, distinctive for a particular ratio of the interaction parameters, brings out a close kinship with the eigenproperties obtained previously for a class of Stark states via the apparatus of supersymmetric quantum mechanics.

  2. Ewald Summation Approach to Potential Models of Aqueous Electrolytes Involving Gaussian Charges and Induced Dipoles: Formal and Simulation Results

    SciTech Connect

    Chialvo, Ariel A.; Vlcek, Lukas

    2014-11-01

    We present a detailed derivation of the complete set of expressions required for the implementation of an Ewald summation approach to handle the long-range electrostatic interactions of polar and ionic model systems involving Gaussian charges and induced dipole moments with a particular application to the isobaricisothermal molecular dynamics simulation of our Gaussian Charge Polarizable (GCP) water model and its extension to aqueous electrolytes solutions. The set comprises the individual components of the potential energy, electrostatic potential, electrostatic field and gradient, the electrostatic force and the corresponding virial. Moreover, we show how the derived expressions converge to known point-based electrostatic counterparts when the parameters, defining the Gaussian charge and induced-dipole distributions, are extrapolated to their limiting point values. Finally, we illustrate the Ewald implementation against the current reaction field approach by isothermal-isobaric molecular dynamics of ambient GCP water for which we compared the outcomes of the thermodynamic, microstructural, and polarization behavior.

  3. Multiconfiguration Dirac-Hartree-Fock calculations of the electric dipole moment of radium induced by the nuclear Schiff moment

    SciTech Connect

    Bieron, Jacek; Gaigalas, Gediminas; Gaidamauskas, Erikas; Fritzsche, Stephan; Indelicato, Paul; Joensson, Per

    2009-07-15

    The multiconfiguration Dirac-Hartree-Fock theory has been employed to calculate the electric dipole moment of the 7s6d {sup 3}D{sub 2} state of radium induced by the nuclear Schiff moment. The results are dominated by valence and core-valence electron correlation effects. We show that the correlation effects can be evaluated in a converged series of multiconfiguration expansions.

  4. Physical origins of mobility degradation in extremely scaled SiO2/HfO2 gate stacks with La and Al induced dipoles

    NASA Astrophysics Data System (ADS)

    Ando, Takashi; Copel, Matt; Bruley, John; Frank, Martin M.; Watanabe, Heiji; Narayanan, Vijay

    2010-03-01

    We demonstrate metal-gate-induced interfacial layer (IL) scaling using a HfO2 dielectric and clarify the kinetics underlying this process. The intrinsic IL scaling effect on electron mobility is separated from La and Al-induced dipole effects. We find that the mobility degradation for La-containing high-κ dielectrics is not due to the La-induced dipole but due to the intrinsic IL scaling effect, whereas the Al-induced dipole brings about additional mobility degradation. This unique nature of the La-induced dipole enables aggressive equivalent oxide thickness scaling down to 0.42 nm without extrinsic mobility degradation when combined with IL scaling.

  5. Electromagnetically induced transparency in rubidium vapor prepared by a comb of short optical pulses

    SciTech Connect

    Sautenkov, Vladimir A.; Rostovtsev, Yuri V.; Ye, C.Y.; Welch, George R.; Kocharovskaya, Olga; Scully, Marlan O.

    2005-06-15

    It was shown by Kocharovskaya and Khanin [Sov. Phys. JETP 63, 945 (1986)] that a comb of optical pulses can induce a ground-state atomic coherence and change the optical response of an atomic medium. In our experiment, we studied the propagation of a comb of optical pulses produced by a mode-locked diode laser in rubidium atomic vapor. Electromagnetically induced transparency (EIT) was observed when the pulse repetition rate is a subharmonic of the hyperfine splitting of the ground state. The width of the EIT resonance is determined by the relaxation rate of the ground-state coherence. Possible applications to magnetometery, atomic clocks, and frequency chains are discussed.

  6. Optomechanically induced transparency in a membrane-in-the-middle setup at room temperature

    NASA Astrophysics Data System (ADS)

    Karuza, M.; Biancofiore, C.; Bawaj, M.; Molinelli, C.; Galassi, M.; Natali, R.; Tombesi, P.; Di Giuseppe, G.; Vitali, D.

    2013-07-01

    We demonstrate the analog of electromagnetically induced transparency in a room temperature cavity optomechanics setup formed by a thin semitransparent membrane within a Fabry-Pérot cavity. Due to destructive interference, a weak probe field is completely reflected by the cavity when the pump beam is resonant with the motional red sideband of the cavity. Under this condition we infer a significant slowing down of light of hundreds of microseconds, which is easily tuned by shifting the membrane along the cavity axis. We also observe the associated phenomenon of electromagnetically induced amplification which occurs due to constructive interference when the pump is resonant with the blue sideband.

  7. Arrayed and checkerboard optical waveguides controlled by the electromagnetically induced transparency

    SciTech Connect

    Li Yongyao; Malomed, Boris A.; Feng Mingneng; Zhou Jianying

    2010-12-15

    We introduce two models of quasidiscrete optical systems: an array of waveguides doped by four-level N-type atoms, and a nonlinear checkerboard pattern, formed by doping with three-level atoms of the {Lambda}-type. The dopant atoms are driven by external fields, to induce the effect of the electromagnetically induced transparency (EIT). These active systems offer advantages and additional degrees of freedom, in comparison with ordinary passive waveguiding systems. In the array of active waveguides, the driving field may adjust linear and nonlinear propagation regimes for a probe signal. The nonlinear checkerboard system supports the transmission of stable spatial solitons and their 'fuzzy' counterparts, straight or oblique.

  8. Electromagnetically induced transparency in an asymmetric double quantum well under non-resonant, intense laser fields

    NASA Astrophysics Data System (ADS)

    Niculescu, E. C.

    2017-02-01

    Electromagnetically induced transparency in an asymmetric double quantum well subjected to a non-resonant, intense laser field is theoretically investigated. We found that the energy levels configuration could be switched between a Λ-type and a ladder-type scheme by varying the non-resonant radiation intensity. This effect is due to the laser-induced electron tunneling between the wells and it allows a substantial flexibility in the manipulation of the optical properties. The dependence of the susceptibilities on the control field Rabi frequency, intensity of the nonresonant laser, and the control field detuning for both configurations are discussed and compared.

  9. Analog electromagnetically induced transparency for circularly polarized wave using three-dimensional chiral metamaterials.

    PubMed

    Lin, Hai; Yang, Dong; Han, Song; Liu, Yangjie; Yang, Helin

    2016-12-26

    In this paper, we theoretically and experimentally demonstrate a three-dimensional metamaterial that can motivate electromagnetic induced transparency (EIT) by using circular polarized wave as stimulations. The unit cell consists of a pair of metallic strips printed on both sides of the printed circuit board (PCB), where a conductive cylinder junction is used to connect the metal strips by drilling a hole inside the substrate. When a right circularly polarized wave is incident, destructive interference is excited between meta-atoms of the 3D structure, the transmission spectrum demonstrates a sharp transparency window. A coupled oscillator model and an electrical equivalent circuit model are applied to quantitatively and qualitatively analyze the coupling mechanism in the EIT-like metamaterial. Analysis in detail shows the EIT window's amplitude and frequency are modulated by changing the degree of symmetry breaking. The proposed metamaterial may achieve potential applications in developing chiral slow light devices.

  10. Tunable ultracompact chip-integrated multichannel filter based on plasmon-induced transparencies

    SciTech Connect

    Yang, Xiaoyu; Chai, Zhen; Lu, Cuicui; Yang, Hong; Hu, Xiaoyong E-mail: qhgong@pku.edu.cn; Gong, Qihuang E-mail: qhgong@pku.edu.cn

    2014-06-02

    Nanoscale multichannel filter is realized in plasmonic circuits directly, which consists of four plasmonic nanocavities coupled via a plasmonic waveguide etched in a gold film. The feature device size is only 1.35 μm, which is reduced by five orders of magnitude compared with previous reports. The optical channels are formed by transparency windows of plasmon-induced transparencies. A shift of 45 nm in the central wavelengths of optical channels is obtained when the plasmonic coupled-nanocavities are covered with a 100-nm-thick poly(methyl methacrylate) layer. This work opens up the possibility for the realization of solid quantum chips based on plasmonic circuits.

  11. Theoretical realization of dynamically tunable double plasmonically induced transparency in a graphene-based waveguide structure

    NASA Astrophysics Data System (ADS)

    Zhang, Zhengren; Fan, Yuancheng; Long, Yang; Yin, Pengfei

    2017-10-01

    A graphene-based waveguide coupled with radiative and subradiant graphene ribbon resonators is proposed to represent the four-level energy diagram in conventional atomic systems and demonstrate a new realization of dynamically tunable double plasmonically induced transparency (DPIT). The radiative resonator is achieved with the help of direct coupling from the graphene waveguide while indirect coupling is relied for the subradiant resonator. By combining the numerical simulation results and the dressed theory, the physical mechanism behind the DPIT is presented in detail. The DPIT phenomenon is derived from the mode splitting caused by the phase-coupled effects. By controlling the Fermi energy level of graphene ribbon, the double transparency windows can be dynamically tuned. The proposed structure may find its application in optical communication or other novel terahertz integrated optical circuits and devices.

  12. Two-photon dichroic atomic vapor laser lock using electromagnetically induced transparency and absorption

    SciTech Connect

    Becerra, F. E.; Willis, R. T.; Rolston, S. L.; Orozco, L. A.

    2009-07-15

    We demonstrate a technique to lock the frequency of a laser to a transition between two excited states in Rb vapor using a two-photon process in the presence of a weak magnetic field. We use a ladder configuration from specific hyperfine sublevels of the 5S{sub 1/2}, 5P{sub 3/2}, and 5D{sub 5/2} levels. This atomic configuration can show electromagnetically induced transparency and absorption processes. The error signal comes from the difference in the transparency or absorption felt by the two orthogonal polarizations of the probe beam. A simplified model is in good quantitative agreement with the observed signals for the experimental parameters. We have used this technique to lock the frequency of the laser up to 1.5 GHz off atomic resonance.

  13. Analog electromagnetically induced transparency for circularly polarized wave using three-dimensional chiral metamaterials

    NASA Astrophysics Data System (ADS)

    Lin, Hai; Yang, Dong; Han, Song; Liu, Yangjie; Yang, Helin

    2016-12-01

    In this paper, we theoretically and experimentally demonstrate a three dimensional metamaterial that can motivate electromagnetic induced transparency (EIT) by using circular polarized wave as stimulations. The unit cell consists of a pair of metallic strips printed on both sides of the printed circuit board (PCB), where a conductive cylinder junction is used to connect the metal strips by drilling a hole inside the substrate. When a right circularly polarized wave is incident, destructive interference is excited between meta-atoms of the 3D structure, the transmission spectrum demonstrates a sharp transparency window. A coupled oscillator model and an electrical equivalent circuit model are applied to quantitatively and qualitatively analyze the coupling mechanism in the EIT-like metamaterial. Analysis in detail shows the EIT window's amplitude and frequency are modulated by changing the degree of symmetry breaking. The proposed metamaterial may achieve potential applications in developing chiral slow light devices.

  14. Classical analogue of electromagnetically induced transparency with a metal-superconductor hybrid metamaterial.

    PubMed

    Kurter, Cihan; Tassin, Philippe; Zhang, Lei; Koschny, Thomas; Zhuravel, Alexander P; Ustinov, Alexey V; Anlage, Steven M; Soukoulis, Costas M

    2011-07-22

    Metamaterials are engineered materials composed of small electrical circuits producing novel interactions with electromagnetic waves. Recently, a new class of metamaterials has been created to mimic the behavior of media displaying electromagnetically induced transparency (EIT). Here we introduce a planar EIT metamaterial that creates a very large loss contrast between the dark and radiative resonators by employing a superconducting Nb film in the dark element and a normal-metal Au film in the radiative element. Below the critical temperature of Nb, the resistance contrast opens up a transparency window along with a large enhancement in group delay, enabling a significant slowdown of waves. We further demonstrate precise control of the EIT response through changes in the superfluid density. Such tunable metamaterials may be useful for telecommunication because of their large delay-bandwidth products.

  15. Terahertz radiation-induced sub-cycle field electron emission across a split-gap dipole antenna

    NASA Astrophysics Data System (ADS)

    Zhang, Jingdi; Zhao, Xiaoguang; Fan, Kebin; Wang, Xiaoning; Zhang, Gu-Feng; Geng, Kun; Zhang, Xin; Averitt, Richard D.

    We use intense terahertz pulses to excite the resonant mode (0.6THz) of a micro-fabricated dipole antenna with a vacuum gap. The dipole antenna structure enhances the peak amplitude of the in-gap THz electric field by a factor of ~170. Above an in-gap E-field threshold amplitude of ~10 MVcm-1, THz-induced field electron emission is observed (TIFEE) as indicated by the field-induced electric current across the dipole antenna gap. Field emission occurs within a fraction of the driving THz period. Our analysis of the current (I) and incident electric field (E) is in agreement with a Millikan-Lauritsen analysis where log (I) exhibits a linear dependence on 1/E. Numerical estimates indicate that the electrons are accelerated to a value of approximately one tenth of the speed of light. (arXiv: 1508.04737) We acknowledge support from DOE-BES No. DE-FG02-09ER46643 and NSF No. ECCS-1309835.

  16. Improved Photo-Induced Stability in Amorphous Metal-Oxide Based TFTs for Transparent Displays.

    PubMed

    Koo, Sang-Mo; Ha, Tae-Jun

    2015-10-01

    In this paper, we investigate the origin of photo-induced instability in amorphous metal-oxide based thin-film transistors (oxide-TFTs) by exploring threshold voltage (Vth) shift in transfer characteristics. The combination of photo irradiation and prolonged gate bias stress enhanced the shift in Vth in amorphous hafnium-indium-zinc-oxide (a-HfIZO) TFTs. Such results stem from the extended trapped charges at the localized defect states related to oxygen vacancy which play a role in a screening effect on the electric field induced by gate voltage. We also demonstrate the chemically clean interface in oxide-TFTs by employing oxygen annealing which reduces the density of trap states, thereby resulting in improved photo-induced stability. We believe that this work stimulates the research society of transparent electronics by providing a promising approach to suppress photo-induced instability in metal-oxide TFTs.

  17. Plasmon-induced transparency by detuned magnetic atoms in trirod metamaterials.

    PubMed

    Ding, Pei; Fan, Chunzhen; Cheng, Yongguang; Liang, Erjun; Xue, Qianzhong

    2012-04-20

    We demonstrate theoretically an analog of electromagnetically induced transparency (EIT) in the plasmonic metamaterial with the unit cell consisting of three parallel metallic rods. The electromagnetic mechanism for the EIT-like transmission is discussed based on our investigation of the localized surface plasmon resonances in three trirod configurations. We find that the transmission minima surrounding the transparency window on both sides correspond to two detuned magnetic resonances, which arise respectively from the antiphase plasmon couplings between a long rod and a short rod and between two short rods. A decrease of more than 10 times in the group velocity can be achieved for the trirod structure at the transparency window in the optical regime, and the EIT-like response can be well described by the theoretical model of two harmonic oscillators. This work not only reveals the EIT-like transmission in plasmonic metamaterial consisting of detuned magnetic "atoms," but also provides further insight into the plasmons' interactions, especially for metallic nanostructures comprising multiple metallic elements.

  18. Focused Electron and Ion Beam Induced Deposition on Flexible and Transparent Polycarbonate Substrates.

    PubMed

    Peinado, Patricia; Sangiao, Soraya; De Teresa, José M

    2015-06-23

    The successful application of focused electron (and ion) beam induced deposition techniques for the growth of nanowires on flexible and transparent polycarbonate films is reported here. After minimization of charging effects in the substrate, sub-100 nm-wide Pt, W, and Co nanowires have been grown and their electrical conduction is similar compared to the use of standard Si-based substrates. Experiments where the substrate is bent in a controlled way indicate that the electrical conduction is stable up to high bending angles, >50°, for low-resistivity Pt nanowires grown by the ion beam. On the other hand, the resistance of Pt nanowires grown by the electron beam changes significantly and reversibly with the bending angle. Aided by the substrate transparency, a diffraction grating in transmission mode has been built based on the growth of an array of Pt nanowires that shows sharp diffraction spots. The set of results supports the large potential of focused beam deposition as a high-resolution nanolithography technique on transparent and flexible substrates. The most promising applications are expected in flexible nano-optics and nanoplasmonics, flexible electronics, and nanosensing.

  19. Analogue of electromagnetically-induced-transparency based on graphene nanotube waveguide

    NASA Astrophysics Data System (ADS)

    Wei, Buzheng; Jian, Shuisheng

    2017-09-01

    A graphene-based nanotube waveguide system is proposed and designed to realize the analogue of electromagnetically-induced-transparency. The two nanotubes act as side coupled cavity rings which can be treated as the bright and dark resonators. By mimicking the quantum nonlinear optical interference, the light at resonant frequency makes the opaque system transparent. Conveniently, the working transparency window can be dynamically controlled by shifting the Fermi energy level of graphene without refabricating the device. Furthermore, the shape of the transmission spectrum can be tuned either by adjusting the waveguide coupling distance or by the cavity ring coupling distance. If the ring radius gets bigger, higher order of modes are excited in the dark resonator consequently. Meaningfully, the light travels at resonant frequency can be efficiently slowed down and the highest group delay reaches 25 ps. In the end, some concerns about the practical realization of such device are discussed. The structure may find potential applications in nano technology or light storage field.

  20. Control of microwave signals using bichromatic electromechanically induced transparency in multimode circuit electromechanical systems

    NASA Astrophysics Data System (ADS)

    Cheng, Jiang; Yuanshun, Cui; Xintian, Bian; Xiaowei, Li; Guibin, Chen

    2016-05-01

    We theoretically investigate the tunable delay and advancement of microwave signals based on bichromatic electromechanically induced transparency in a three-mode circuit electromechanical system, where two nanomechanical resonators with closely spaced frequencies are independently coupled to a common microwave cavity. In the presence of a strong microwave pump field, we obtain two transparency windows accompanied by steep phase dispersion in the transmitted microwave probe field. The width of the transparency window and the group delay of the probe field can be controlled effectively by the power of the pump field. It is shown that the maximum group delay of 0.12 ms and the advancement of 0.27 ms can be obtained in the current experiments. Project supported by the National Natural Science Foundation of China (Grant Nos. 11304110 and 11174101), the Jiangsu Natural Science Foundation, China (Grant Nos. BK20130413 and BK2011411), and the Natural Science Foundation of Jiangsu Higher Education Institutions of China (Grant Nos. 13KJB140002 and 15KJB460004).

  1. Coherent-interference-induced transparency based on long-range air-hole assisted subwavelength waveguides

    NASA Astrophysics Data System (ADS)

    Zhou, Wen; Huang, Xu Guang; Tan, Qilong; Liang, Yao; Lao, Jieer; Chen, Zanhui

    2014-11-01

    A novel coherent-interference-induced transparency (CIT) system consisting of two coupled and detuned double-sided-branch (DSB) filters in a long-range air-hole assisted subwavelength (LR-AHAS) waveguide has been proposed and numerically demonstrated. The resonant wavelength, maximum transmittance, full width at half maximum (FWHM) and phase dispersion of the transparent window can be effectively tuned by adjusting the detuning and phase-shift between two coupled DSB filters, and FWHM can be suppressed to as small as 1.6 nm, which is much narrower than that of an individual resonator in an LR-AHAS waveguide. The FWHMs of 3.2 nm and 5.2 nm with the corresponding group refractive indices ng of 73 and 45 have been respectively demonstrated. In addition, multiple transparent peaks with an average bandwidth of 3.6 nm and high transmittance of 0.74 can be achieved by cascading more detuned DSB filters into the system. It provides a new approach to develop tunable high-channel-count bandpass filters and optical buffers based on the LR-AHAS waveguide platform for large-scale photonic integrations.

  2. Time-resolved study of femtosecond laser induced micro-modifications inside transparent brittle materials

    NASA Astrophysics Data System (ADS)

    Hendricks, F.; Matylitsky, V. V.; Domke, M.; Huber, Heinz P.

    2016-03-01

    Laser processing of optically transparent or semi-transparent, brittle materials is finding wide use in various manufacturing sectors. For example, in consumer electronic devices such as smartphones or tablets, cover glass needs to be cut precisely in various shapes. The unique advantage of material processing with femtosecond lasers is efficient, fast and localized energy deposition in nearly all types of solid materials. When an ultra-short laser pulse is focused inside glass, only the localized region in the neighborhood of the focal volume absorbs laser energy by nonlinear optical absorption. Therefore, the processing volume is strongly defined, while the rest of the target stays unaffected. Thus ultra-short pulse lasers allow cutting of the chemically strengthened glasses such as Corning Gorilla glass without cracking. Non-ablative cutting of transparent, brittle materials, using the newly developed femtosecond process ClearShapeTM from Spectra-Physics, is based on producing a micron-sized material modification track with well-defined geometry inside. The key point for development of the process is to understand the induced modification by a single femtosecond laser shot. In this paper, pump-probe microscopy techniques have been applied to study the defect formation inside of transparent materials, namely soda-lime glass samples, on a time scale between one nanosecond to several tens of microseconds. The observed effects include acoustic wave propagation as well as mechanical stress formation in the bulk of the glass. Besides better understanding of underlying physical mechanisms, our experimental observations have enabled us to find optimal process parameters for the glass cutting application and lead to better quality and speed for the ClearShapeTM process.

  3. Electromagnetically induced transparency in the four-level system driven by bichromatic microwave field

    NASA Astrophysics Data System (ADS)

    Yang, Lijun; Sun, Ke-jia; Zhang, Su-heng; Feng, Xiao-min

    2014-11-01

    We present a theoretical study on the nonlinear behaviors of the electromagnetically induced transparency resonance subject to two microwave driving fields in a four-level atom system. The probe absorption spectrum is obtained by solving numerically the relevant equations of density matrix. It is shown that there are two pairs of the EIT windows in the probe absorption spectrum. The two pairs of EIT windows have symmetry with respect to the resonance frequency of the probe field, and the separation is equal to the Rabi frequency of the resonant microwave driving field. But in each pair, the splitting of two EIT windows is dominated to the strength of detuning microwave driving field.

  4. Creation of an Effective Magnetic Field in Ultracold Atomic Gases Using Electromagnetically Induced Transparency

    SciTech Connect

    Juzeliunas, G.; Oehberg, P.

    2005-09-15

    We consider the influence of the control and probe beams in the electromagnetically induced transparency configuration on the mechanical motion of ultracold atomic gases (atomic Bose-Einstein condensates or degenerate Fermi gases). We carry out a microscopic analysis of the interplay between radiation and matter and show that the two beams of light can provide an effective magnetic field acting on electrically neutral atoms in the case where the probe beam has an orbital angular momentum. As an example, we demonstrate how a Meissner-like effect can be created in an atomic Bose-Einstein condensate.

  5. Tunable Multiple Optomechanically Induced Transparency with Squeezed Fields in an Optomechanical System

    NASA Astrophysics Data System (ADS)

    Wang, Qiong; Yao, Chun-Mei; Wu, Qin-Qin; He, Zhi

    2016-12-01

    A tunable multiple windows optomechanically induced transparency (OMIT) with a squeezed field is investigated in a system consisting of an optomechanical cavity coupled to a charged nanomechanical resonator (NAMR) via Coulomb interaction. Such a multiple OMIT can be achieved by adjusting the frequency of the charged NAMR and can be observed even with a single-photon squeezed field. In addition, this multiple OMIT for the quantized fields can be robust against cavity decay and environmental temperature. Specifically, the model under our consideration might be applied to precision measurement the frequency difference of two NAMRs within the reach of current techniques.

  6. Inducing transparency with large magnetic response and group indices by hybrid dielectric metamaterials.

    PubMed

    Chen, Cheng-Kuang; Lai, Yueh-Chun; Yang, Yu-Hang; Chen, Chia-Yun; Yen, Ta-Jen

    2012-03-26

    We present metamaterial-induced transparency (MIT) phenomena with enhanced magnetic fields in hybrid dielectric metamaterials. Using two hybrid structures of identical-dielectric-constant resonators (IDRs) and distinct-dielectric-constant resonators (DDRs), we demonstrate a larger group index (ng~354), better bandwidth-delay product (BDP~0.9) than metallic-type metamaterials. The keys to enable these properties are to excite either the trapped mode or the suppressed mode resonances, which can be managed by controlling the contrast of dielectric constants between the dielectric resonators in the hybrid metamaterials.

  7. Observation of Doppler-free electromagnetically induced transparency in atoms selected optically with specific velocity

    SciTech Connect

    Yu, Hoon; Kim, Kwan Su; Kim, Jung Dong; Lee, Hyun Kyung; Kim, Jung Bog

    2011-11-15

    We observed an electromagnetically induced transparency signal in a four-level system with optically selected rubidium atoms at specific velocities in a room-temperature vaporized cell. Since the atoms behave like cold atoms in the selected atomic view, the observed signals coincide with a trapped atomic system. According to this result, we can observe Doppler-free signals, which correspond from 1.2 to 1.0 K in a Doppler-broadened medium. And the selected atoms have velocity components of {+-}(131 {+-} 3) MHz per wave number. Our experimental results can provide insight for research in cold media.

  8. Atom-membrane cooling and entanglement using cavity electromagnetically induced transparency

    SciTech Connect

    Genes, Claudiu; Ritsch, Helmut; Drewsen, Michael; Dantan, Aurelien

    2011-11-15

    We investigate a hybrid optomechanical system composed of a micromechanical oscillator as a movable membrane and an atomic three-level ensemble within an optical cavity. We show that a suitably tailored cavity field response via electromagnetically induced transparency (EIT) in the atomic medium allows for strong coupling of the membrane's mechanical oscillations to the collective atomic ground-state spin. This facilitates ground-state cooling of the membrane motion, quantum state mapping, and robust atom-membrane entanglement even for cavity widths larger than the mechanical resonance frequency.

  9. Multilayer-WS{sub 2}:ferroelectric composite for ultrafast tunable metamaterial-induced transparency applications

    SciTech Connect

    Yang, Xiaoyu; Yang, Jinghuan; Zhu, Yu; Yang, Hong; Hu, Xiaoyong Gong, Qihuang

    2015-08-24

    An ultrafast and low-power all-optical tunable metamaterial-induced transparency is realized, using polycrystalline barium titanate doped gold nanoparticles and multilayer tungsten disulfide microsheets as nonlinear optical materials. Large nonlinearity enhancement is obtained associated with quantum confinement effect, local-field effect, and reinforced interaction between light and multilayer tungsten disulfide. Low threshold pump intensity of 20 MW/cm{sup 2} is achieved. An ultrafast response time of 85 ps is maintained because of fast carrier relaxation dynamics in nanoscale crystal grains of polycrystalline barium titanate. This may be useful for the study of integrated photonic devices based on two-dimensional materials.

  10. High-sensitivity optical Faraday magnetometry with intracavity electromagnetically induced transparency

    NASA Astrophysics Data System (ADS)

    Zhang, Qiaolin; Sun, Hui; Fan, Shuangli; Guo, Hong

    2016-12-01

    We suggest a multiatom cavity quantum electrodynamics system for the detection of a weak magnetic field, based on Faraday rotation with intracavity electromagnetically induced transparency. Our study demonstrates that the collective coupling between the cavity modes and the atomic ensemble can be used to improve the sensitivity. With single-probe photon input, the sensitivity is inversely proportional to the number of atoms, and a sensitivity of 2.45 nT Hz-1/2 could be attained. With multiphoton measurement, our numerical calculations show that the magnetic field sensitivity can be improved to 105.6 aT Hz-1/2 with realistic experimental conditions.

  11. Analogue of electromagnetically induced transparency in integrated plasmonics with radiative and subradiant resonators.

    PubMed

    Wang, Ting; Zhang, Yusheng; Hong, Zhi; Han, Zhanghua

    2014-09-08

    We propose the use of radiative and subradiant resonators coupled to a metal-insulator-metal waveguide to represent the three-level energy diagram in conventional atomic systems and demonstrate a new realization of on-chip plasmonic analogue of electromagnetically-induced transparency (EIT) in integrated plasmonics. The radiative resonator is achieved with the help of aperture-coupling while evanescent coupling is relied for the subradiant resonator. Numerical simulation results demonstrate well-pronounced intermediate transmission peak through the bus waveguide and also show that the EIT effect can be easily controlled by the relative position of the two Fabry-Perot resonators.

  12. Coherent interference induced transparency in self-coupled optical waveguide-based resonators.

    PubMed

    Zhou, Linjie; Ye, Tong; Chen, Jianping

    2011-01-01

    We propose a self-coupled optical waveguide (SCOW)-based resonator to generate an optical resonance analogous to electromagnetically induced transparency (EIT). The EIT-like effect is formed by the coherent interference between two resonance paths inherent to the SCOW resonator. For cascaded SCOW resonators, the spectrum they produce is significantly affected by the phase shift between them, with the EIT-like peak flattened or split as the two extreme cases. We also investigate the dispersion characteristics of an infinite array of SCOW resonators and show that the dispersion relation and group index in the EIT subband can be greatly changed by a small phase shift between the SCOW resonators.

  13. A stable frequency comb directly referenced to rubidium electromagnetically induced transparency and two-photon transitions

    NASA Astrophysics Data System (ADS)

    Hou, Dong; Wu, Jiutao; Zhang, Shuangyou; Ren, Quansheng; Zhang, Zhigang; Zhao, Jianye

    2014-03-01

    We demonstrate an approach to create a stable erbium-fiber-based frequency comb at communication band by directly locking the combs to two rubidium atomic transitions resonances (electromagnetically induced transparency absorption and two-photon absorption), respectively. This approach directly transfers the precision and stability of the atomic transitions to the comb. With its distinguishing feature of compactness by removing the conventional octave-spanning spectrum and f-to-2f beating facilities and the ability to directly control the comb's frequency at the atomic transition frequency, this stable optical comb can be widely used in optical communication, frequency standard, and optical spectroscopy and microscopy.

  14. Novel oscillator model with damping factor for plasmon induced transparency in waveguide systems.

    PubMed

    Zhao, Mingzhuo; Li, Hongjian; He, Zhihui; Chen, Zhiquan; Xu, Hui; Zheng, Mingfei

    2017-09-06

    We introduce a novel two-oscillator model with damping factor to describe the plasmon induced transparency (PIT) in a bright-dark model plasmonic waveguide system. The damping factor γ in the model can be calculated from metal conductor damping factor γ c and dielectric damping factor γ d . We investigate the influence of geometry parameters and damping factor γ on transmission spectra as well as slow-light effects in the plasmonic waveguide system. We can find an obvious PIT phenomenon and realize a considerable slow-light effect in the double-cavities system. This work may provide guidance for optical switching and plasmon-based information processing.

  15. Amplified light storage with high fidelity based on electromagnetically induced transparency in rubidium atomic vapor

    NASA Astrophysics Data System (ADS)

    Zhou, Wei; Wang, Gang; Tang, Guoyu; Xue, Yan

    2016-06-01

    By using slow and stored light based on electromagnetically induced transparency (EIT), we theoretically realize the storage of optical pulses with enhanced efficiency and high fidelity in ensembles of warm atoms in 85Rb vapor cells. The enhancement of storage efficiency is achieved by introducing a pump field beyond three-level configuration to form a N-type scheme, which simultaneously inhibits the undesirable four-wave mixing effect while preserves its fidelity. It is shown that the typical storage efficiency can be improved from 29% to 53% with the application of pump field. Furthermore, we demonstrate that this efficiency decreases with storage time and increases over unity with optical depth.

  16. Optical switching of cross intensity correlation in cavity electromagnetically induced transparency

    NASA Astrophysics Data System (ADS)

    Rao, Shi; Hu, Xiangming; Xu, Jun; Li, Lingchao

    2017-03-01

    We present optical switching of cross intensity correlation in the context of cavity electromagnetically induced transparency configuration. For symmetrical parameters, the cross intensity correlation switches from negative to positive as the atom–pump detunings change symmetrically from one case to the other. In terms of the dressed atomic states and the Bogoliubov modes we analyze the atom–photon interaction mechanism for the switching behavior, and present a numerical verification. As a by-product, we show noise squeezing of the sum or difference intensity in a limited region of parameters.

  17. Precision Mass Measurement with Optomechanically Induced Transparency in an Optomechanical System

    NASA Astrophysics Data System (ADS)

    Wang, Qiong; Li, Wen-Juan; Ma, Peng-Cheng; He, Zhi

    2017-07-01

    We present a scheme for all-optical precision mass sensing with squeezed field in an optomechanical system in terms of optomechanically induced transparency (OMIT). We demonstrate that the splitting of the two peaks of the OMIT, which is almost inverse proportion to square root of the accreted mass landing on nanomechanical resonator (NAMR). We also show that the mass measurement scheme for the squeezed fields can be robust against temperature and cavity decay in somehow. Specifically, the precision measurement is from the noise spectrum, for these reasons, our scheme may provide a new paradigm for precision measurement based on the noise in the optomechanical system.

  18. A stable frequency comb directly referenced to rubidium electromagnetically induced transparency and two-photon transitions

    SciTech Connect

    Hou, Dong; Wu, Jiutao; Zhang, Shuangyou; Ren, Quansheng; Zhang, Zhigang; Zhao, Jianye

    2014-03-17

    We demonstrate an approach to create a stable erbium-fiber-based frequency comb at communication band by directly locking the combs to two rubidium atomic transitions resonances (electromagnetically induced transparency absorption and two-photon absorption), respectively. This approach directly transfers the precision and stability of the atomic transitions to the comb. With its distinguishing feature of compactness by removing the conventional octave-spanning spectrum and f-to-2f beating facilities and the ability to directly control the comb's frequency at the atomic transition frequency, this stable optical comb can be widely used in optical communication, frequency standard, and optical spectroscopy and microscopy.

  19. Indirect laser-induced breakdown of transparent thin gel layer for sensitive trace element detection

    NASA Astrophysics Data System (ADS)

    Xiu, Junshan; Bai, Xueshi; Negre, Erwan; Motto-Ros, Vincent; Yu, Jin

    2013-06-01

    Optical emissions from major and trace elements embodied in a transparent gel prepared from cooking oil were detected when the gel was spread in thin film on a metallic substrate and a plasma was induced on the substrate surface using nanosecond infrared pulsed laser. Such emissions are due to indirect breakdown of the coating layer. The generated plasma, a mixture of substances from the substrate, the layer, and the ambient gas, was characterized using emission spectroscopy. Temperature higher than 15 000 K determined in the plasma allows considering sensitive detection of trace elements in liquids, gels, biological samples, or thin films.

  20. Formation of vortex dipoles

    NASA Astrophysics Data System (ADS)

    Afanasyev, Y. D.

    2006-03-01

    Evolution of a two-dimensional flow induced by a jet ejected from a nozzle of finite size is studied experimentally. Vortex dipole forms at the front of the developing flow while a trailing jet establishes behind the dipole. The dynamics of the flow is discussed on the basis of detailed measurements of vorticity and velocity fields which are obtained using particle image velocimetry. It is found that dipoles do not separate (pinch-off) from the trailing jet for values of the stroke ratio up to 15, which fact can be contrasted with the behavior of vortex rings reported previously by other authors. A characteristic time scale that is defined differently from the formation time of vortex rings can be introduced. This time scale (startup time) indicates the moment when the dipole starts translating after an initial period when it mainly grows absorbing the jet from the nozzle. A simple model that considers the competing effects of expansion and translation is developed to obtain an estimate of the dimensionless startup time. The dynamics of a dipole after the formation is characterized by a reduced flux of vorticity from the jet. The dipole moves forward with constant speed such that a value of the ratio of the speed of propagation of the dipole to the mean velocity of the jet is found to be 0.5. A universality of this ratio is explained in the framework of a model based on conservation of mass and momentum for the moving dipole.

  1. Molecular detection with terahertz waves based on absorption-induced transparency metamaterials

    NASA Astrophysics Data System (ADS)

    G. Rodrigo, Sergio; Martín-Moreno, L.

    2016-10-01

    A system for the detection of spectral signatures of chemical compounds at the Terahertz regime is presented. The system consists on a holey metal film whereby the presence of a given substance provokes the appearance of spectral features in transmission and reflection induced by the molecular specimen. These induced effects can be regarded as an extraordinary optical transmission phenomenon called absorption-induced transparency (AIT). The phenomenon consist precisely in the appearance of peaks in transmission and dips in reflection after sputtering of a chemical compound onto an initially opaque holey metal film. The spectral signatures due to AIT occur unexpectedly close to the absorption energies of the molecules. The presence of a target, a chemical compound, would be thus revealed as a strong drop in reflectivity measurements. We theoretically predict the AIT based system would serve to detect amounts of hydrocyanic acid (HCN) at low rate concentrations.

  2. Tunable electromagnetically induced transparency in hybrid graphene/all-dielectric metamaterial

    NASA Astrophysics Data System (ADS)

    Zhu, Lei; Dong, Liang; Guo, Jing; Meng, Fan-Yi; Wu, Qun

    2017-03-01

    We proposed a hybrid graphene/dielectric structure to achieve tunable electromagnetically induced transparency (EIT) effect. Unit cell of hybrid structure consists of a graphene strip as bright element and a dielectric split ring resonator (DSRR) as quasi-dark element. The destructive inference between dipolar plasmon resonance induced by graphene strip and Mie resonance induced by DSRR leads to famous EIT effect. By altering physical sizes of two resonant elements and their couplings, EIT resonance can be effectively controlled. In particular, EIT window and effective group index can be dynamically dominated by varying graphene strip's Fermi level. This active manipulation is also confirmed using "two-particle" model. More interestingly, EIT resonance can be also effectively modulated through controlling incident angles for electromagnetic (EM) waves. These results would have promising applications in areas of tunable slow light devices and new filters.

  3. F2-Laser-Induced Modification of Aluminum Thin Films into Transparent Aluminum Oxide

    NASA Astrophysics Data System (ADS)

    Okoshi, Masayuki; Iwai, Kazufumi; Nojiri, Hidetoshi; Inoue, Narumi

    2012-12-01

    A vacuum-UV F2 laser of 157 nm wavelength induced strong oxidation of 10-nm-thick Al thin films, forming transparent Al2O3 on silica glass. The laser-induced modification occurred at the surface of Al thin films; consequently, the thickness of the formed Al2O3 thin films increased linearly with increasing number of F2 laser photons. The formation of equivalent-phase Al2O3 thin films was confirmed by X-ray photoelectron spectroscopy. The oxidation reaction in the laser-induced modification of 10-nm-thick Al thin films was slower than that for 20- and 60-nm-thick Al thin films. Morphological changes leading to the crystallization of the Al2O3 thin films were also observed when the thickness of Al thin films increased from 10 to 20 and 60 nm.

  4. Motion induced second order temperature and y-type anisotropies after the subtraction of linear dipole in the CMB maps

    SciTech Connect

    Sunyaev, Rashid A.; Khatri, Rishi E-mail: khatri@mpa-garching.mpg.de

    2013-03-01

    y-type spectral distortions of the cosmic microwave background allow us to detect clusters and groups of galaxies, filaments of hot gas and the non-uniformities in the warm hot intergalactic medium. Several CMB experiments (on small areas of sky) and theoretical groups (for full sky) have recently published y-type distortion maps. We propose to search for two artificial hot spots in such y-type maps resulting from the incomplete subtraction of the effect of the motion induced dipole on the cosmic microwave background sky. This dipole introduces, at second order, additional temperature and y-distortion anisotropy on the sky of amplitude few μK which could potentially be measured by Planck HFI and Pixie experiments and can be used as a source of cross channel calibration by CMB experiments. This y-type distortion is present in every pixel and is not the result of averaging the whole sky. This distortion, calculated exactly from the known linear dipole, can be subtracted from the final y-type maps, if desired.

  5. Plasmon-Induced Transparency by Hybridizing Concentric-Twisted Double Split Ring Resonators

    PubMed Central

    Parvinnezhad Hokmabadi, Mohammad; Philip, Elizabath; Rivera, Elmer; Kung, Patrick; Kim, Seongsin M.

    2015-01-01

    As a classical analogue of electromagnetically induced transparency, plasmon induced transparency (PIT) has attracted great attention by mitigating otherwise cumbersome experimental implementation constraints. Here, through theoretical design, simulation and experimental validation, we present a novel approach to achieve and control PIT by hybridizing two double split ring resonators (DSRRs) on flexible polyimide substrates. In the design, the large rings in the DSRRs are stationary and mirror images of each other, while the small SRRs rotate about their center axes. Counter-directional rotation (twisting) of the small SRRs is shown to lead to resonance shifts, while co-directional rotation results in splitting of the lower frequency resonance and emergence of a PIT window. We develop an equivalent circuit model and introduce a mutual inductance parameter M whose sign is shown to characterize the existence or absence of PIT response from the structure. This model attempts to provide a quantitative measure of the physical mechanisms underlying the observed PIT phenomenon. As such, our findings can support the design of several applications such as optical buffers, delay lines, and ultra-sensitive sensors. PMID:26507006

  6. Ultra-slow light propagation by self-induced transparency in ruby in the superhyperfine limit.

    PubMed

    Riesen, Hans; Rebane, Aleksander; Rajan, Rajitha Papakutty; Hutchison, Wayne; Ganschow, Steffen; Szabo, Alex

    2017-05-15

    Self-induced transparency is reported for circularly polarized light in the R1(-3/2) line of a 30 ppm ruby (α-Al2O3:Cr3+) at 1.7 K in a magnetic field of B‖c=4.5  T. In such a field and temperature, a 30 ppm ruby is in the so-called superhyperfine limit resulting in a long phase memory time, TM=50  μs, and a thousand-fold slower pulse propagation velocity of ∼300  m/s was observed, compared to the ∼300  km/s measured in the first observation of self-induced transparency (SIT) ∼50 years ago, that employed a ruby with a 500 ppm chromium concentration in zero field and at 4.2 K. To date, this is the slowest pulse propagation ever observed in a SIT experiment.

  7. Plasmon-Induced Transparency by Hybridizing Concentric-Twisted Double Split Ring Resonators

    NASA Astrophysics Data System (ADS)

    Parvinnezhad Hokmabadi, Mohammad; Philip, Elizabath; Rivera, Elmer; Kung, Patrick; Kim, Seongsin M.

    2015-10-01

    As a classical analogue of electromagnetically induced transparency, plasmon induced transparency (PIT) has attracted great attention by mitigating otherwise cumbersome experimental implementation constraints. Here, through theoretical design, simulation and experimental validation, we present a novel approach to achieve and control PIT by hybridizing two double split ring resonators (DSRRs) on flexible polyimide substrates. In the design, the large rings in the DSRRs are stationary and mirror images of each other, while the small SRRs rotate about their center axes. Counter-directional rotation (twisting) of the small SRRs is shown to lead to resonance shifts, while co-directional rotation results in splitting of the lower frequency resonance and emergence of a PIT window. We develop an equivalent circuit model and introduce a mutual inductance parameter M whose sign is shown to characterize the existence or absence of PIT response from the structure. This model attempts to provide a quantitative measure of the physical mechanisms underlying the observed PIT phenomenon. As such, our findings can support the design of several applications such as optical buffers, delay lines, and ultra-sensitive sensors.

  8. Electromagnetically induced transparency and wideband wavelength conversion in silicon nitride microdisk optomechanical resonators.

    PubMed

    Liu, Yuxiang; Davanço, Marcelo; Aksyuk, Vladimir; Srinivasan, Kartik

    2013-05-31

    We demonstrate optomechanically mediated electromagnetically induced transparency and wavelength conversion in silicon nitride (Si3N4) microdisk resonators. Fabricated devices support whispering gallery optical modes with a quality factor (Q) of 10(6), and radial breathing mechanical modes with a Q=10(4) and a resonance frequency of 625 MHz, so that the system is in the resolved sideband regime. Placing a strong optical control field on the red (blue) detuned sideband of the optical mode produces coherent interference with a resonant probe beam, inducing a transparency (absorption) window for the probe. This is observed for multiple optical modes of the device, all of which couple to the same mechanical mode, and which can be widely separated in wavelength due to the large band gap of Si3N4. These properties are exploited to demonstrate frequency up-conversion and down-conversion of optical signals between the 1300 and 980 nm bands with a frequency span of 69.4 THz.

  9. ``Cold Denaturation'' induces inversion of dipole and spin transfer in chiral peptide monolayers

    NASA Astrophysics Data System (ADS)

    Sarkar, Soumyajit; Eckshtain-Levi, Meital; Capua, Eyal; Refaely-Abramson, Sivan; Gavrilov, Yulian; Mathew, Shinto; Paltiel, Yossi; Levy, Yaakov; Kronik, Leeor; Naaman, Ron

    Using a combination of several experimental and computational techniques, we show that the α-helix structure of oligopeptides based on alanine and aminoisobutyric acid is transformed to a more linear conformation upon cooling, due to interaction with neighboring molecules in a self-assembled monolayer (SAM) structure. This process is similar to the known ``cold denaturation'' in peptides, but here the SAM plays the role of the solvent. Our DFT-based first principles calculations show that the structural change results in a flip in the direction of the electrical dipole moment of the adsorbed molecules. The dipole flip is accompanied by an associated change in the spin channel that is preferred in electron transfer through the molecules. This is also experimentally observed via a new solid state hybrid organic-inorganic device that is based on the Hall effect, but operates with no external magnetic field or magnetic material.

  10. Torque for electron spin induced by electron permanent electric dipole moment

    SciTech Connect

    Senami, Masato E-mail: akitomo@scl.kyoto-u.ac.jp; Fukuda, Masahiro E-mail: akitomo@scl.kyoto-u.ac.jp; Ogiso, Yoji E-mail: akitomo@scl.kyoto-u.ac.jp; Tachibana, Akitomo E-mail: akitomo@scl.kyoto-u.ac.jp

    2014-10-06

    The spin torque of the electron is studied in relation to the electric dipole moment (EDM) of the electron. The spin dynamics is known to be given by the spin torque and the zeta force in quantum field theory. The effect of the EDM on the torque of the spin brings a new term in the equation of motion of the spin. We study this effect for a solution of the Dirac equation with electromagnetic field.

  11. Dipole-forbidden atomic transitions induced by superintense x-ray laser fields

    NASA Astrophysics Data System (ADS)

    Simonsen, Aleksander Skjerlie; Førre, Morten

    2016-06-01

    A hydrogen atom, initially prepared in the 2 s and/or 2 p (m =±1 ) states, is assumed irradiated by 0.8 keV (1.5 nm) photons in pulses of 1 -250 fs duration and intensities in the range 1020 to 1023W /cm2 . Solving the corresponding time-dependent Schrödinger equation from first principles, we show that the ionization and excitation dynamics of the laser-atom system is strongly influenced by interactions beyond the electric dipole approximation. A beyond-dipole two-photon Raman-like transition between the 2 s and 2 p (m =±1 ) states is found to completely dominate the underlying laser-matter interaction. It turns out that the large difference in the ionization rates of the 2 s and 2 p (m =±1 ) states is important in this context, effectively leading to a symmetry breaking in the corresponding (beyond-dipole) bound-bound dynamics with the result that a net population transfer between the states occurs throughout the laser-matter interaction period. Varying the x-ray exposure time as well as the laser intensity, we probe the phenomenon as the bound wave packet oscillates between having 2 s and 2 p (m =±1 ) character, eventually giving rise to a Rabi-like oscillation pattern in the populations.

  12. Measuring the Forces between Magnetic Dipoles

    ERIC Educational Resources Information Center

    Gayetsky, Lisa E.; Caylor, Craig L.

    2007-01-01

    We describe a simple undergraduate lab in which students determine how the force between two magnetic dipoles depends on their separation. We consider the case where both dipoles are permanent and the case where one of the dipoles is induced by the field of the other (permanent) dipole. Agreement with theoretically expected results is quite good.

  13. Force-induced transparency and conversion between slow and fast light in optomechanics

    NASA Astrophysics Data System (ADS)

    Wu, Zhen; Luo, Ren-Hua; Zhang, Jian-Qi; Wang, Yu-Hua; Yang, Wen; Feng, Mang

    2017-09-01

    The optomechanics can generate fantastic effects of optics due to appropriate mechanical control. Here we theoretically study effects of slow and fast lights in a single-sided optomechanical cavity with an external force. The force-induced transparency of slow and fast lights and the force-dependent conversion between the slow and fast lights result from effects of the rotating-wave approximation (RWA) and the anti-RWA, which can be controlled by properly modifying the effective cavity frequency due to the external force. These force-induced phenomena can be applied to control the light group velocity and to detect the force variation, which are feasible using current laboratory techniques.

  14. Image information transfer via electromagnetically induced transparency-based slow light

    NASA Astrophysics Data System (ADS)

    Wang, Xiao-Xiao; Sun, Jia-Xiang; Sun, Yuan-Hang; Li, Ai-Jun; Chen, Yi; Zhang, Xiao-Jun; Kang, Zhi-Hui; Wang, Lei; Wang, Hai-Hua; Gao, Jin-Yue

    2015-07-01

    In this work, we experimentally demonstrate an image information transfer between two channels by using slow light based on electromagnetically induced transparency (EIT) in a solid. The probe optical image is slowed due to steep dispersion induced by EIT. By applying an additional control field to an EIT-driven medium, the slowed image is transferred into two information channels. Image intensities between two information channels can be controlled by adjusting the intensities of the control fields. The similarity of output images is further analyzed. This image information transfer allows for manipulating images in a controlled fashion, and will be important in further information processing. Project supported by the National Basic Research Program of China (Grant No. 2011CB921603), the National Natural Science Foundation of China (Grant Nos. 11374126, 11347137, 11204103, 11404336, and 11204029), and the Fund for Fostering Talents in Basic Science of the National Natural Science Foundation of China (Grant No. J1103202).

  15. Electromagnetically induced transparency with large delay-bandwidth product induced by magnetic resonance near field coupling to electric resonance

    SciTech Connect

    Li, Hai-ming; Liu, Shao-bin Liu, Si-yuan; Zhang, Hai-feng; Bian, Bo-rui; Kong, Xiang-kun; Wang, Shen-yun

    2015-03-16

    In this paper, we numerically and experimentally demonstrate electromagnetically induced transparency (EIT)-like spectral response with magnetic resonance near field coupling to electric resonance. Six split-ring resonators and a cut wire are chosen as the bright and dark resonator, respectively. An EIT-like transmission peak located between two dips can be observed with incident magnetic field excitation. A large delay bandwidth product (0.39) is obtained, which has potential application in quantum optics and communications. The experimental results are in good agreement with simulated results.

  16. Identification of dipole disorder in low temperature solution processed oxides: its utility and suppression for transparent high performance solution-processed hybrid electronics† †Electronic supplementary information (ESI) available. CCDC 1478230. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c6sc01962e Click here for additional data file. Click here for additional data file.

    PubMed Central

    Warwick, Christopher; Lang, Jiang; Broch, Katharina; Halpert, Jonathan E.; Socratous, Josephine; Brown, Adam; Leedham, Timothy

    2016-01-01

    The ability to deposit high-quality inorganic semiconductors and dielectrics from solution at low process temperatures (∼200 °C) has become a very important research focus. During the course of our investigation, we identify the presence of an induced dipole present in solid state solution processed inorganic oxide insulator layers processed at reduced temperature (200–350 °C) from either molecular precursors, or well-dispersed metal oxide nanoparticles. Chemical composition analysis coupled with electrical measurements shows that the dielectric instability occurs due to proton migration via the Grotthuss mechanism inducing a long lived dipole disorder. Thus we established conditions for suppressing this effect to afford “ideal” high-k dielectric layer. Using this methodology, solution processed all inorganic thin film transistors (TFTs) with charge carrier mobilities exceeding 6 cm2 V–1 s–1 operating at low voltage (5 V) have been achieved. In addition, we show the broad utility of the perovskite high-k dielectric when processed with state of the art polymer and single crystal organic semiconductors yielding mobilities of approx. 7 cm2 V–1 s–1 at only 4 V. These transparent devices demonstrate excellent electrical device stability and a threshold voltage shift of only 0.41 V over 14 h, which is comparable, or better than sputtered oxide films. PMID:28567246

  17. In situ diagnostics of pulse laser-induced defects in DUV transparent fused silica glasses

    NASA Astrophysics Data System (ADS)

    Mühlig, Ch.; Triebel, W.; Bark-Zollmann, S.; Grebner, D.

    2000-05-01

    Excimer laser pulses (λ=248 or 193 nm) induce transient and permanent defects in optical glasses of high UV transparency. Such defects are causing additional absorption and changes of density and refractive index, respectively (compaction). The interaction of each laser pulse with different OH-rich fused silica samples was investigated by real time measurements of laser-induced fluorescence (LIF) and of Raman spectra excited by the 248 nm KrF-excimer laser. The irradiation of the glasses with energy densities of about 10 mJ/cm2 and more induces E‧ and NBOH defects simultaneously. The laser-induced fluorescence of NBOH defect centres at 650 nm characterises the kinetics of defect generation and relaxation. The primary absorption process is the two-photon absorption of KrF laser pulses. The relaxation of defects in the time interval between the laser pulses is mainly influenced by diffusion limited processes. Locally resolved LIF and Raman spectra allow the investigation of homogeneity and laser damage stability in large area substrates (e.g. for mask blanks). Raman spectra excited by KrF laser pulses are measured to detect precursors and intermediates of laser-induced defects and molecular hydrogen in the glass matrix. The detection limit of H2 molecules is in the range of 1017 cm-3. A correlation between LIF intensities and H2 concentrations is found.

  18. Polarized linewidth-controllable double-trapping electromagnetically induced transparency spectra in a resonant plasmon nanocavity

    PubMed Central

    Wang, Luojia; Gu, Ying; Chen, Hongyi; Zhang, Jia-Yu; Cui, Yiping; Gerardot, Brian D.; Gong, Qihuang

    2013-01-01

    Surface plasmons with ultrasmall optical mode volume and strong near field enhancement can be used to realize nanoscale light-matter interaction. Combining surface plasmons with the quantum system provides the possibility of nanoscale realization of important quantum optical phenomena, including the electromagnetically induced transparency (EIT), which has many applications in nonlinear quantum optics and quantum information processing. Here, using a custom-designed resonant plasmon nanocavity, we demonstrate polarized position-dependent linewidth-controllable EIT spectra at the nanoscale. We analytically obtain the double coherent population trapping conditions in a double-Λ quantum system with crossing damping, which give two transparent points in the EIT spectra. The linewidths of the three peaks are extremely sensitive to the level spacing of the excited states, the Rabi frequencies and detunings of pump fields, and the Purcell factors. In particular the linewidth of the central peak is exceptionally narrow. The hybrid system may have potential applications in ultra-compact plasmon-quantum devices. PMID:24096943

  19. Low-loss planar metamaterials electromagnetically induced transparency for sensitive refractive index sensing

    NASA Astrophysics Data System (ADS)

    Tian, Ying; Hu, Sen; Huang, Xiaojun; Yu, Zetai; Lin, Hai; Yang, Helin

    2017-10-01

    A low-loss and high transmission electromagnetically induced transparency like (EIT- like) structure is experimentally and numerically demonstrated in this paper. The proposed planar structure based on EIT-like metamaterial consists of two separate split-ring resonators, and its resulting transmission level can maximally reach 0.89 with significant suppression of radiation loss. According to the effective medium theory, the imaginary parts of the effective permittivity and permeability of the metamaterial are used as the evidence of low-loss. In the analysis, the simulated surface current, magnetic field distribution and coupled oscillator model reveal the principle of high transmittance EIT-effect. Furthermore, the peak of transparency frequency is highly sensitive to the variation of refractive index in the background medium. The sensor based on the proposed EIT structure can achieve a sensitivity of 1.69 GHz/RIU (refractive index unit) and a figure of merit of 11.66. Such metamaterials have potential perspectives in sensing and chiral slow light devices.

  20. Electromagnetically induced transparency of a plasmonic metamaterial light absorber based on multilayered metallic nanoparticle sheets.

    PubMed

    Okamoto, Koichi; Tanaka, Daisuke; Degawa, Ryo; Li, Xinheng; Wang, Pangpang; Ryuzaki, Sou; Tamada, Kaoru

    2016-11-08

    In this study, we observed the peak splitting of absorption spectra for two-dimensional sheets of silver nanoparticles due to the electromagnetically induced transparency (EIT) effect. This unique optical phenomenon was observed for the multilayered nanosheets up to 20 layers on a metal substrate, while this phenomenon was not observed on a transparent substrate. The wavelength and intensities of the split peaks depend on the number of layers, and the experimental results were well reproduced by the calculation of the Transfer-Matrix method by employing the effective medium approximation. The Ag nanosheets used in this study can act as a plasmonic metamaterial light absorber, which has a such large oscillator strength. This phenomenon is a fundamental optical property of a thin film on a metal substrate but has never been observed because native materials do not have a large oscillator strength. This new type of EIT effect using a plasmonic metamaterial light absorber presents the potential for the development of future optic and photonic technologies.

  1. Tunable electromagnetically induced transparency at terahertz frequencies in coupled graphene metamaterial

    NASA Astrophysics Data System (ADS)

    Ding, Guo-Wen; Liu, Shao-Bin; Zhang, Hai-Feng; Kong, Xiang-Kun; Li, Hai-Ming; Li, Bing-Xiang; Liu, Si-Yuan; Li, Hai

    2015-11-01

    A graphene-based metamaterial with tunable electromagnetically induced transparency (EIT)-like transmission is numerically studied in this paper. The proposed structure consists of a graphene layer composed of coupled cut-wire pairs printed on a substrate. The simulation confirms that an EIT-like transparency window can be observed due to indirect coupling in a terahertz frequency range. More importantly, the peak frequency of the transmission window can be dynamically controlled over a broad frequency range by varying the Fermi energy levels of the graphene layer through controlling the electrostatic gating. The proposed metamaterial structure offers an additional opportunity to design novel applications such as switches or modulators. Project supported by the National Natural Science Foundation of China (Grant No. 61307052), the Youth Funding for Science & Technology Innovation in Nanjing University of Aeronautics and Astronautics, China (Grant No. NS2014039), the Chinese Specialized Research Fund for the Doctoral Program of Higher Education (Grant No. 20123218110017), the Innovation Program for Graduate Education of Jiangsu Province, China (Grant Nos. KYLX_0272, CXZZ13_0166, and CXLX13_155), the Open Research Program in National State Key Laboratory of Millimeter Waves of China (Grant No. K201609), and the Fundamental Research Funds for the Central Universities of China (Grant No. kfjj20150407).

  2. Photon drag enhancement by a slow-light moving medium via electromagnetically-induced transparency amplification

    NASA Astrophysics Data System (ADS)

    Iqbal, Azmat; Khan, Naveed; Bacha, Bakht Amin; Rahman, Amin Ur; Ahmad, Afaq

    2017-09-01

    Recently, a considerable enhancement has been observed in the celebrated Fresnel-Fizeau light drag by innovative experimental and theoretical approaches because of its fundamental and practical interest in the emerging technology of quantum optics and photonics. We present a semiclassical density matrix approach on the demonstration of light drag in a slow-light moving medium comprising five-level single tripod atomic configuration. To accomplish this, we introduce Kerr-type nonlinearity that leads to electromagnetically-induced transparency amplification under resonance conditions. By switching ON Kerr-type nonlinearity effect, we observe a prominent transparency window in probe field's absorption spectrum whose width and amplitude can be controlled further by the intensity of Kerr field and control field. The incorporation of Kerr field also switches light propagation from superluminal to subluminal domain. We predict a significant enhancement both in the lateral and the rotary photon drag owing to drag of light linear polarization state subjected to translation and rotation of the host medium, respectively. Consistent with earlier results, light drag considerably depends on both transverse and angular velocity of the host medium. In regime of subluminal propagation, light polarization state drags along the medium motion while in the superluminal propagation region it drags opposite to the medium motion.

  3. Capillary-Force-Induced Cold Welding in Silver-Nanowire-Based Flexible Transparent Electrodes.

    PubMed

    Liu, Yuan; Zhang, Jianming; Gao, Heng; Wang, Yan; Liu, Qingxian; Huang, Siya; Guo, Chuan Fei; Ren, Zhifeng

    2017-02-08

    Silver nanowire (AgNW) films have been studied as the most promising flexible transparent electrodes for flexible photoelectronics. The wire-wire junction resistance in the AgNW film is a critical parameter to the electrical performance, and several techniques of nanowelding or soldering have been reported to reduce the wire-wire junction resistance. However, these methods require either specific facilities, or additional materials as the "solder", and often have adverse effects to the AgNW film or substrate. In this study, we show that at the nanoscale, capillary force is a powerful driving force that can effectively cause self-limited cold welding of the wire-wire junction for AgNWs. The capillary-force-induced welding can be simply achieved by applying moisture on the AgNW film, without any technical support like the addition of materials or the use of specific facilities. The moisture-treated AgNW films exhibit a significant decrease in sheet resistance, but negligible changes in transparency. We have also demonstrated that this method is effective to heal damaged AgNW films of wearable electronics and can be conveniently performed not only indoors but also outdoors where technical support is often unavailable. The capillary-force-based method may also be useful in the welding of other metal NWs, the fabrication of nanostructures, and smart assemblies for versatile flexible optoelectronic applications.

  4. Electromagnetically induced transparency of a plasmonic metamaterial light absorber based on multilayered metallic nanoparticle sheets

    PubMed Central

    Okamoto, Koichi; Tanaka, Daisuke; Degawa, Ryo; Li, Xinheng; Wang, Pangpang; Ryuzaki, Sou; Tamada, Kaoru

    2016-01-01

    In this study, we observed the peak splitting of absorption spectra for two-dimensional sheets of silver nanoparticles due to the electromagnetically induced transparency (EIT) effect. This unique optical phenomenon was observed for the multilayered nanosheets up to 20 layers on a metal substrate, while this phenomenon was not observed on a transparent substrate. The wavelength and intensities of the split peaks depend on the number of layers, and the experimental results were well reproduced by the calculation of the Transfer-Matrix method by employing the effective medium approximation. The Ag nanosheets used in this study can act as a plasmonic metamaterial light absorber, which has a such large oscillator strength. This phenomenon is a fundamental optical property of a thin film on a metal substrate but has never been observed because native materials do not have a large oscillator strength. This new type of EIT effect using a plasmonic metamaterial light absorber presents the potential for the development of future optic and photonic technologies. PMID:27824071

  5. Electromagnetically induced transparency of a plasmonic metamaterial light absorber based on multilayered metallic nanoparticle sheets

    NASA Astrophysics Data System (ADS)

    Okamoto, Koichi; Tanaka, Daisuke; Degawa, Ryo; Li, Xinheng; Wang, Pangpang; Ryuzaki, Sou; Tamada, Kaoru

    2016-11-01

    In this study, we observed the peak splitting of absorption spectra for two-dimensional sheets of silver nanoparticles due to the electromagnetically induced transparency (EIT) effect. This unique optical phenomenon was observed for the multilayered nanosheets up to 20 layers on a metal substrate, while this phenomenon was not observed on a transparent substrate. The wavelength and intensities of the split peaks depend on the number of layers, and the experimental results were well reproduced by the calculation of the Transfer-Matrix method by employing the effective medium approximation. The Ag nanosheets used in this study can act as a plasmonic metamaterial light absorber, which has a such large oscillator strength. This phenomenon is a fundamental optical property of a thin film on a metal substrate but has never been observed because native materials do not have a large oscillator strength. This new type of EIT effect using a plasmonic metamaterial light absorber presents the potential for the development of future optic and photonic technologies.

  6. Numerical Study on the Partitioning of the Molecular Polarizability into Fluctuating Charge and Induced Atomic Dipole Contributions

    PubMed Central

    Mei, Ye; Simmonett, Andrew C.; Pickard, Frank C.; DiStasio, Robert A.; Brooks, Bernard R.; Shao, Yihan

    2015-01-01

    In order to carry out a detailed analysis of the molecular static polarizability, which is the response of the molecule to a uniform external electric field, the molecular polarizability was computed using the finite-difference method for 21 small molecules, using density functional theory. Within nine charge population schemes (Löwdin, Mulliken, Becke, Hirshfeld, CM5, Hirshfeld-I, NPA, CHELPG, MK-ESP) in common use, the charge fluctuation contribution is found to dominate the molecular polarizability, with its ratio ranging from 59.9% with the Hirshfeld or CM5 scheme to 96.2% with the Mulliken scheme. The Hirshfeld-I scheme is also used to compute the other contribution to the molecular polarizability coming from the induced atomic dipoles, and the atomic polarizabilities in 8 small molecules and water pentamer are found to be highly anisotropic for most atoms. Overall, the results suggest that (a) more emphasis probably should be placed on the charge fluctuation terms in future polarizable force field development; (b) an anisotropic polarizability might be more suitable than an isotropic one in polarizable force fields based entirely or partially on the induced atomic dipoles. PMID:25945749

  7. Numerical study on the partitioning of the molecular polarizability into fluctuating charge and induced atomic dipole contributions

    SciTech Connect

    Mei, Ye; Simmonett, Andrew C.; Pickard, IV, Frank C.; DiStasio, Jr., Robert A.; Brooks, Bernard R.; Shao, Yihan

    2015-05-06

    In order to carry out a detailed analysis of the molecular static polarizability, which is the response of the molecule to a uniform external electric field, the molecular polarizability was computed in this study using the finite-difference method for 21 small molecules, using density functional theory. Within nine charge population schemes (Lowdin, Mulliken, Becke, Hirshfeld, CM5, Hirshfeld-I, NPA, CHELPG, MK-ESP) in common use, the charge fluctuation contribution is found to dominate the molecular polarizability, with its ratio ranging from 59.9% with the Hirshfeld or CM5 scheme to 96.2% with the Mulliken scheme. The Hirshfeld-I scheme is also used to compute the other contribution to the molecular polarizability coming from the induced atomic dipoles, and the atomic polarizabilities in eight small molecules and water pentamer are found to be highly anisotropic for most atoms. In conclusion, the overall results suggest that (a) more emphasis probably should be placed on the charge fluctuation terms in future polarizable force field development and (b) an anisotropic polarizability might be more suitable than an isotropic one in polarizable force fields based entirely or partially on the induced atomic dipoles.

  8. Numerical study on the partitioning of the molecular polarizability into fluctuating charge and induced atomic dipole contributions

    DOE PAGES

    Mei, Ye; Simmonett, Andrew C.; Pickard, IV, Frank C.; ...

    2015-05-06

    In order to carry out a detailed analysis of the molecular static polarizability, which is the response of the molecule to a uniform external electric field, the molecular polarizability was computed in this study using the finite-difference method for 21 small molecules, using density functional theory. Within nine charge population schemes (Lowdin, Mulliken, Becke, Hirshfeld, CM5, Hirshfeld-I, NPA, CHELPG, MK-ESP) in common use, the charge fluctuation contribution is found to dominate the molecular polarizability, with its ratio ranging from 59.9% with the Hirshfeld or CM5 scheme to 96.2% with the Mulliken scheme. The Hirshfeld-I scheme is also used to computemore » the other contribution to the molecular polarizability coming from the induced atomic dipoles, and the atomic polarizabilities in eight small molecules and water pentamer are found to be highly anisotropic for most atoms. In conclusion, the overall results suggest that (a) more emphasis probably should be placed on the charge fluctuation terms in future polarizable force field development and (b) an anisotropic polarizability might be more suitable than an isotropic one in polarizable force fields based entirely or partially on the induced atomic dipoles.« less

  9. Numerical study on the partitioning of the molecular polarizability into fluctuating charge and induced atomic dipole contributions.

    PubMed

    Mei, Ye; Simmonett, Andrew C; Pickard, Frank C; DiStasio, Robert A; Brooks, Bernard R; Shao, Yihan

    2015-06-04

    In order to carry out a detailed analysis of the molecular static polarizability, which is the response of the molecule to a uniform external electric field, the molecular polarizability was computed using the finite-difference method for 21 small molecules, using density functional theory. Within nine charge population schemes (Löwdin, Mulliken, Becke, Hirshfeld, CM5, Hirshfeld-I, NPA, CHELPG, MK-ESP) in common use, the charge fluctuation contribution is found to dominate the molecular polarizability, with its ratio ranging from 59.9% with the Hirshfeld or CM5 scheme to 96.2% with the Mulliken scheme. The Hirshfeld-I scheme is also used to compute the other contribution to the molecular polarizability coming from the induced atomic dipoles, and the atomic polarizabilities in eight small molecules and water pentamer are found to be highly anisotropic for most atoms. Overall, the results suggest that (a) more emphasis probably should be placed on the charge fluctuation terms in future polarizable force field development and (b) an anisotropic polarizability might be more suitable than an isotropic one in polarizable force fields based entirely or partially on the induced atomic dipoles.

  10. Flexible bent rod model with a saturating induced dipole moment to study the electric linear dichroism of DNA fragments

    NASA Astrophysics Data System (ADS)

    Bertolotto, Jorge A.; Umazano, Juan P.

    2016-06-01

    In the present work we make a theoretical study of the steady state electric linear dichroism of DNA fragments in aqueous solution. The here developed theoretical approach considers a flexible bent rod model with a saturating induced dipole moment. The electric polarizability tensor of bent DNA fragments is calculated considering a phenomenological model which theoretical and experimental backgroung is presented here. The model has into account the electric polarizability longitudinal and transversal to the macroion. Molecular flexibility is described using an elastic potential. We consider DNA fragments originally bent with bending fluctuations around an average bending angle. The induced dipole moment is supposed constant once the electric field strength grows up at critical value. To calculate the reduced electric linear dichroism we determine the optical factor considering the basis of the bent DNA perpendicular to the molecular axis. The orientational distribution function has into account the anisotropic electric properties and the molecule flexibility. We applied the present theoretical background to fit electric dichroism experimental data of DNA fragments reported in the bibliography in a wide range of molecular weight and electric field. From these fits, values of DNA physical properties are estimated. We compare and discuss the results here obtained with the theoretical and experimental data presented by other authors. The original contributions of this work are: the inclusion of the transversal electric polarizability saturating with the electric field, the description of the electric properties with an electric polarizability tensor dependant on the bending angle and the use of an arc model originally bent.

  11. Ewald Summation Approach to Potential Models of Aqueous Electrolytes Involving Gaussian Charges and Induced Dipoles: Formal and Simulation Results

    DOE PAGES

    Chialvo, Ariel A.; Vlcek, Lukas

    2014-11-01

    We present a detailed derivation of the complete set of expressions required for the implementation of an Ewald summation approach to handle the long-range electrostatic interactions of polar and ionic model systems involving Gaussian charges and induced dipole moments with a particular application to the isobaricisothermal molecular dynamics simulation of our Gaussian Charge Polarizable (GCP) water model and its extension to aqueous electrolytes solutions. The set comprises the individual components of the potential energy, electrostatic potential, electrostatic field and gradient, the electrostatic force and the corresponding virial. Moreover, we show how the derived expressions converge to known point-based electrostatic counterpartsmore » when the parameters, defining the Gaussian charge and induced-dipole distributions, are extrapolated to their limiting point values. Finally, we illustrate the Ewald implementation against the current reaction field approach by isothermal-isobaric molecular dynamics of ambient GCP water for which we compared the outcomes of the thermodynamic, microstructural, and polarization behavior.« less

  12. Ferroelectric BaTiO3 dipole induced charge transfer enhancement in dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Feng, Keyuan; Liu, Xiaoyan; Si, Donghui; Tang, Xiao; Xing, An; Osada, Minoru; Xiao, Peng

    2017-05-01

    BaTiO3/TiO2 nanocomposite films with varied amount of BaTiO3 are fabricated and applied as photoanodes for dye-sensitized solar cells (DSCs) and demonstrated enhanced power conversion efficiency. Ferroelectricity of BaTiO3 in the film after subjected to a annealing process up to 450 °C is examined by Switching Spectroscopy Piezoresponse Force Microscopy (SSPFM). The highest performance is achieved in 1.0 wt% BaTiO3 addition as a result of increased photocurrent density (Jsc) and fill factor (FF), regardless of reduction of dye-loading. Electrochemical impedance spectroscopy (EIS) measurements at different bias voltages (≦Voc) in dark suggest that ferroelectric dipole induced electric field has positive effects on enhancing electron mobility and suppressing charge recombination. Although more detailed experiments are needed in designing of the nanocomposite films for compensating characteristics of dye-loading and electron mobility, introduction of ferroelectric dipole induced electric field into the photoanode would be a good strategy in achieving further improvement of power conversion efficiency of DSCs through improved charge transfer properties.

  13. Dipole-switch induced modification of the emissive response of carbon nanotubes.

    PubMed

    Gläske, Mareen; Bluemmel, Pascal; Juergensen, Sabrina; Setaro, Antonio; Reich, Stephanie

    2017-09-20

    The interaction of carbon nanotubes with the molecular dipole switch spiropyran is expected to affect the optical response of the tubes. Until now, the need of anchor groups to immobilize the switches on the tubes has hindered experimental observation of effects of switching on the emission behavior of the tubes. Here we present spiropyran-carbon nanotubes complexes obtained by micelle swelling. This method does not require any anchor nor sophisticated chemistry to warrant close tube-switch proximity. For the first time we observe the shifts predicted theoretically and their effect on the tubes' excitation and emission energies. © 2017 IOP Publishing Ltd.

  14. Experimental Study of Synchro-Betatron Coupling Induced By Dipole Modulation

    SciTech Connect

    Syphers, M.; Ball, M.; Brabson, B.; Budnick, J.; Caussyn, D.D.; Chao, A.W.; Collins, J.; Derenchuk, V.; Dutt, S.; East, G.; Ellison, M.; Ellison, T.; Friesel, D.; Gabella, W.; Hamilton, B.; Huang, H.; Jones, W.P.; Lee, S.Y.; Li, D.; Minty, M.G.; Nagaitsev, S.; /Unlisted /Indiana U., IUCF /SLAC /Fermilab /Argonne /Brookhaven

    2011-11-04

    Synchro-betatron coupling in a proton storage ring with electron cooling was studied experimentally by modulating a transverse dipole field close to the synchrotron frequency. The combination of the electron cooling and transverse field modulation on the synchrotron oscillation is equivalent to a dissipative parametric resonant system. The proton bunch was observed to split longitudinally into two pieces, or beamlets, converging toward attractors of the dissipative system. These phenomena might be important in understanding the effect of ground vibration on the Superconducting Super Collider beam, and the effect of power supply ripple on the Relativistic Heavy-Ion Collider beam.

  15. Local spin torque induced by electron electric dipole moment in the YbF molecule

    SciTech Connect

    Fukuda, Masahiro; Senami, Masato; Ogiso, Yoji; Tachibana, Akitomo

    2014-10-06

    In this study, we show the modification of the equation of motion of the electronic spin, which is derived by the quantum electron spin vorticity principle, by the effect of the electron electric dipole moment (EDM). To investigate the new contribution to spin torque by EDM, using first principle calculations, we visualize distributions of the local spin angular momentum density and local spin torque density of the YbF molecule on which the static electric field and magnetic field are applied at t = 0.

  16. Effect of electromagnetically induced transparency on the spectrum of defect modes in a one-dimensional photonic crystal

    SciTech Connect

    Arkhipkin, Vasilii G; Myslivets, S A

    2009-02-28

    We studied the transmission spectrum of a one-dimensional photonic crystal containing a defect layer in which electromagnetically induced transparency is possible. The analysis is performed taking into account the spatial inhomogeneity of interacting fields in the photonic crystal. It is found that the transmission spectrum of such a photonic crystal depends on the spatial overlap of defect modes excited by probe and control radiations. It is shown that electromagnetically induced transparency can result in a considerable narrowing of the defect mode spectrum. (nonlinear optical phenomena)

  17. Tevatron AC dipole system

    SciTech Connect

    Miyamoto, R.; Kopp, S.E.; Jansson, A.; Syphers, M.J.; /Fermilab

    2007-06-01

    The AC dipole is an oscillating dipole magnet which can induce large amplitude oscillations without the emittance growth and decoherence. These properties make it a good tool to measure optics of a hadron synchrotron. The vertical AC dipole for the Tevatron is powered by an inexpensive high power audio amplifier since its operating frequency is approximately 20 kHz. The magnet is incorporated into a parallel resonant system to maximize the current. The use of a vertical pinger magnet which has been installed in the Tevatron made the cost relatively inexpensive. Recently, the initial system was upgraded with a more powerful amplifier and oscillation amplitudes up to 2-3{sigma} were achieved with the 980 GeV proton beam. This paper discusses details of the Tevatron AC dipole system and also shows its test results.

  18. Optical control of light propagation in photonic crystal based on electromagnetically induced transparency

    NASA Astrophysics Data System (ADS)

    Dan, Wang; Jin-Ze, Wu; Jun-Xiang, Zhang

    2016-06-01

    A kind of photonic crystal structure with modulation of the refractive index is investigated both experimentally and theoretically for exploiting electromagnetically induced transparency (EIT). The combination of EIT with periodically modulated refractive index medium gives rise to high efficiency reflection as well as forbidden transmission in a three-level atomic system coupled by standing wave. We show an accurate theoretical simulation via transfer-matrix theory, automatically accounting for multilayer reflections, thus fully demonstrate the existence of photonic crystal structure in atomic vapor. Project supported by the National Natural Science Foundation of China (Grant No. 11574188) and the Project for Excellent Research Team of the National Natural Science Foundation of China (Grant No. 61121064).

  19. Fano resonances and electromagnetically induced transparency in silicon waveguides loaded with plasmonic nanoresonators

    NASA Astrophysics Data System (ADS)

    Ortuño, Rubén; Cortijo, Mario; Martínez, Alejandro

    2017-02-01

    The fundamental electric dipolar resonance of metallic nanostrips placed on top of a dielectric waveguide can be excited via evanescent wave coupling, thus giving rise to broad dips in the transmission spectrum of the waveguide. Here we show via numerical simulations that narrower and steeper Fano-like resonances can be obtained by asymmetrically coupling in the near field a larger nanostrip—supporting an electric quadrupole in the frequency regime of interest—to the original, shorter nanostrip. Under certain conditions, the spectral response corresponding to the electromagnetically induced transparency phenomenon is observed. We suggest that this hybrid plasmonic-photonic approach could be especially relevant for sensing or all-optical switching applications in a photonic integrated platform such as silicon photonics.

  20. Tunable double optomechanically induced transparency in a dual-species Bose–Einstein condensate

    NASA Astrophysics Data System (ADS)

    Liu, Liwei; Zhang, Guoheng; Wang, Xiangli

    2017-10-01

    A novel technique for generating double optomechanically induced transparency (OMIT) in a weak probe field in an optomechanical system is proposed. This system consists of a cigar-shaped dual-species Bose–Einstein condensate which is trapped inside a high-finesse Fabry–Perot cavity. Analytical solutions are given for the absorption and dispersion spectra. The interspecies interaction and the coupling strengths have, as a result, the appearance of two distinct OMIT windows in the absorption spectrum. Furthermore, the coupling strengths, interspecies and intraspecies interaction strengths are used to control the OMIT behavior. We give a certain set of experimental parameters for observing these phenomena in the laboratory. The technique presented may have potential applications in quantum engineering and quantum information networks.

  1. Subluminal and superluminal terahertz radiation in metamaterials with electromagnetically induced transparency.

    PubMed

    Bai, Zhengyang; Hang, Chao; Huang, Guoxiang

    2013-07-29

    We propose a scheme to design a new type of optical metamaterial that can mimic the functionality of four-state atomic systems of N-type energy-level configuration with electromagnetically induced transparency (EIT). We show that in such metamaterial a transition from a single EIT to a double EIT of terahertz radiation may be easily achieved by actively tuning the intensity of the infrared pump field or passively tuning the geometrical parameters of resonator structures. In addition, the group velocity of the terahertz radiation can be varied from subluminal to superluminal by changing the pump field intensity. The scheme suggested here may be used to construct chip-scale slow and fast light devices and to realize rapidly responded switching of terahertz radiation at room temperature.

  2. Vector magnetometry based on electromagnetically induced transparency in linearly polarized light

    SciTech Connect

    Yudin, V. I.; Taichenachev, A. V.; Dudin, Y. O.; Velichansky, V. L.; Zibrov, A. S.; Zibrov, S. A.

    2010-09-15

    We develop a generalized principle of electromagnetically induced transparency (EIT) vector magnetometry based on high-contrast EIT resonances and the symmetry of atom-light interaction in the linearly polarized bichromatic fields. Operation of such vector magnetometer on the D{sub 1} line of {sup 87}Rb has been demonstrated. The proposed compass-magnetometer has an increased immunity to shifts produced by quadratic Zeeman and ac-Stark effects, as well as by atom-buffer gas and atom-atom collisions. In our proof-of-principle experiment the detected angular sensitivity to magnetic field orientation is 10{sup -3} deg/Hz{sup 1/2}, which is limited by laser intensity fluctuations, light polarization quality, and magnitude of the magnetic field.

  3. Paschen-Back effects and Rydberg-state diamagnetism in vapor-cell electromagnetically induced transparency

    NASA Astrophysics Data System (ADS)

    Ma, L.; Anderson, D. A.; Raithel, G.

    2017-06-01

    We report on rubidium vapor-cell Rydberg electromagnetically induced transparency (EIT) in a 0.7 T magnetic field where all involved levels are in the hyperfine Paschen-Back regime, and the Rydberg state exhibits a strong diamagnetic interaction. Signals from both 85Rb and 87Rb are present in the EIT spectra. Isotope-mixed Rb cells allow us to measure the field strength to within a ±0.12 % relative uncertainty. The measured spectra are in excellent agreement with the results of a Monte Carlo calculation and indicate unexpectedly large Rydberg-level dephasing rates. Line shifts and broadenings due to magnetic-field inhomogeneities are included in the model.

  4. Electromagnetically induced transparency metamaterial based on spoof localized surface plasmons at terahertz frequencies

    NASA Astrophysics Data System (ADS)

    Liao, Zhen; Liu, Shuo; Ma, Hui Feng; Li, Chun; Jin, Biaobing; Cui, Tie Jun

    2016-06-01

    We numerically and experimentally demonstrate a plasmonic metamaterial whose unit cell is composed of an ultrathin metallic disk and four ultrathin metallic spiral arms at terahertz frequencies, which supports both spoof electric and magnetic localized surface plasmon (LSP) resonances. We show that the resonant wavelength is much larger than the size of the unit particle, and further find that the resonant wavelength is very sensitive to the particle’s geometrical dimensions and arrangements. It is clearly illustrated that the magnetic LSP resonance exhibits strong dependence to the incidence angle of terahertz wave, which enables the design of metamaterials to achieve an electromagnetically induced transparency effect in the terahertz frequencies. This work opens up the possibility to apply for the surface plasmons in functional devices in the terahertz band.

  5. Coherent pump-probe spectroscopy in sodium vapor: From electromagnetically induced transparency to parametric amplification

    SciTech Connect

    Takahashi, Ken-ichi; Hayashi, Nobuhito; Kido, Hiroaki; Sugimura, Shota; Hombo, Naoya; Mitsunaga, Masaharu

    2011-06-15

    We have theoretically and experimentally investigated coherent pump-probe spectra for the 3S{sub 1/2}-3P{sub 1/2} D1 transition of sodium atomic vapor. Probe transmission spectra in the presence of a coupling beam exhibit dramatic changes depending on experimental conditions. In the weak-excitation, low-atomic-density limit, the spectra are mainly characterized by electromagnetically induced transparency (EIT) and saturated absorption, but for the strong-excitation, high-density case, parametric amplification (PA) is dominant, featuring high probe gain and Stokes-wave generation. We have developed a theory that can explain these two seemingly totally different phenomena (EIT and PA) within the same theoretical framework by manipulating a few experimentally controllable parameters, and have successfully reproduced the observed spectra. Other than the main spectral features, many other interesting physical processes have been predicted and observed.

  6. Controllable double tunneling induced transparency and solitons formation in a quantum dot molecule.

    PubMed

    She, Yanchao; Zheng, Xuejun; Wang, Denglong; Zhang, Weixi

    2013-07-15

    We consider the coupling effect between interdot tunneling coupling and external optical control field to study the linear optical property and the formation of temporal optical solitons in a quantum dot molecules system, analytically. The results show that the double tunneling induced transparency (TIT) windows are appeared in the absorption curve of probe field because of the formation of dynamic Stark splitting and quantum destructive interference effect from the two upper levels. Interestingly, the width of the TIT window becomes wider with the increasing intensity of the optical control field. We also find that the Kerr nonlinear effect of the probe field can be modulated effectively through coherent control both the control field and the interdot tunneling coupling in this system. Meanwhile, we demonstrate that the formation of dark or bright solitons can be practical regulated by varying the intensity of the optical control field.

  7. Manipulation of tunneling induced transparency windows and optical switching features in fivefold quantum dot molecules

    NASA Astrophysics Data System (ADS)

    Hamedi, H. R.; Reza Mehmannavaz, Mohammad

    2015-09-01

    Transient and steady-state behavior of the probe absorption in a multiple quantum dot (QD) molecule composed of five quantum dots molecules (with a center dot and four satellite dots) is explored with application in all-optical switching. We find that the absorption spectra of the light pulse can be efficiently modified via the effect of inter-dot tunnel couplings of QDs and incoherent pumping field. Results show that depending on the values of system parameters, at least one and at most four tunneling induced transparency (TIT) windows can be established in the multiple QD medium. We then investigate the dynamical behavior of the probe absorption-amplification as well as the optical switching in pulsed regime. By adjusting the incoherent pumping rate, the required switching time for changing the gain to the absorption or vice versa is then estimated approximately to be 20.7 nanosecond (ns), that is an appropriate time for such a QDM-based switch.

  8. Slow terahertz light via resonant tunneling induced transparency in quantum well heterostructures

    NASA Astrophysics Data System (ADS)

    Tzenov, Petar; Jirauschek, Christian

    2016-01-01

    We present a theoretical and computational investigation of the possibility of achieving slow terahertz light by exploiting the tunneling induced transparency (TIT) effect in suitably engineered quantum well heterostructure devices. We design such a meta-material and show how TIT could lead to large values of the group refractive index, unfortunately at the cost of strong field attenuation due to decoherence. As a suitable alternative, we propose a grating, consisting of a buffer and a quantum cascade amplifier regions, arranged in such a way as to achieve slow light and simultaneously compensate for the large signal losses. Our calculations show that a binary message could be reliably transmitted through this system, with non-critical reduction of the signal to noise ratio, as we achieve a slow-down factor of more than 70.

  9. Optical precursors with tunneling-induced transparency in asymmetric quantum wells

    NASA Astrophysics Data System (ADS)

    Peng, Yandong; Niu, Yueping; Qi, Yihong; Yao, Haifeng; Gong, Shangqing

    2011-01-01

    A scheme for separating optical precursors from a square-modulated laser pulse through an asymmetric double AlxGa1-xAs/GaAs quantum-well structure via resonant tunneling is proposed. Destructive interference inhibits linear absorption, and a tunneling-induced transparency (TIT) window appears with normal dispersion, which delays the main pulse; then optical precursors are obtained. Due to resonant tunneling, constructive interference for nonlinear susceptibility is created. The enhanced dispersion in a narrow TIT window is about one order of magnitude larger than that of the linear case. In this case, the main pulse is much delayed and the precursor signals are easier to obtain. Moreover, the main pulse builds up due to the gain introduced by the enhanced cross-nonlinearity.

  10. Resonators induced transparency and optical switching assisted by optofluidic pump system

    NASA Astrophysics Data System (ADS)

    Chen, Fang; Sun, Li-Hui

    2016-12-01

    A tunable plasmonic induced transparency (PIT)-based light switching is proposed and investigated. The proposed structure consists of a bus waveguide, two nanoresonators and an optofluidic pump system for actively tuning the system’s transmission. By using the finite difference time domain method, it is found that the interferences between the dark and bright mode resonators can be controlled by manipulating the fluid filled in the resonator, leading to an actively tunable plasmonic switch, the transmittance can be flexibly tuned from near unity to zero. The structure in our paper has the following advantages, such as ultracompact size and easy fabrication. Our study will provide a possibility for designing the ultrafast devices in highly integrated optical circuits.

  11. Tailoring polarization of electromagnetically induced transparency based on non-centrosymmetric metasurfaces

    NASA Astrophysics Data System (ADS)

    Li, Hai-ming; Xue, Feng

    2017-09-01

    In this manuscript, tailoring polarization of analogy of electromagnetically induced transparency (EIT-like) based on non-centrosymmetric metasurfaces has been numerically and experimentally demonstrated. The EIT-like metamaterial is composed of a rectangle ring and two cut wires. The rectangle ring and the cut wire are chosen as the bright mode and the quasi-dark mode, respectively. Under the incident electromagnetic wave excitation, a polarization insensitive EIT-like transmission window can be observed at specific polarization angles. Within the transmission window, the phase steeply changes, which leads to the large group index. Tailoring polarization of EIT-like metamaterial with large group index at specific polarization angles may have potential application in slow light devices.

  12. Nonparaxial self-accelerating beams in an atomic vapor with electromagnetically induced transparency.

    PubMed

    Zhong, Hua; Zhang, Yiqi; Zhang, Zhaoyang; Li, Changbiao; Zhang, Da; Zhang, Yanpeng; Belić, Milivoj R

    2016-12-15

    We theoretically and numerically investigate the nonparaxial self-accelerating beams in a Λ-type three-level energy system of rubidium atomic vapor in the electromagnetically induced transparency (EIT) window. In the EIT window, the absorption of the atomic vapor is small, and robust nonparaxial self-accelerating beams can be generated. The reason is that the energy of the tail transfers to the main lobe, which then maintains its shape, owing to the self-healing effect. Media with large absorption would demand large energy to compensate, and the tail would be lifted too high to maintain the profile of an accelerating beam, so that self-accelerating beams cannot be obtained any longer. An atomic vapor with small absorption is the ideal medium to produce such self-accelerating beams and, in return, self-accelerating beams may inspire new ideas in the research associated with atomic vapors and atomic-like ensembles.

  13. Efficient ion acceleration by relativistic self-induced transparency in subwavelength targets

    NASA Astrophysics Data System (ADS)

    Choudhary, Shivani; Holkundkar, Amol R.

    2016-10-01

    We studied the effect of target thickness on relativistic self-induced transparency (RSIT) and observed that, for subwavelength targets, the corresponding threshold target density (beyond which the target is opaque to an incident laser pulse of given intensity) increases. The accelerating longitudinal electrostatic field created by RSIT from the subwavelength target is then used to accelerate the ions from a thin, low density layer behind the main target to 100 MeV using a 6 cycle flat-top (with rise and fall of one cycle each) circularly polarized laser with peak dimensionless amplitude of 20. A suitable scaling law for optimum laser and target conditions is also deduced. We observed that, as far as energy spectrum is concerned, an extra low density layer is more advantageous than relying on target ions alone.

  14. Tunable high-channel-count bandstop graphene plasmonic filters based on plasmon induced transparency.

    PubMed

    Zhang, Zhengren; Long, Yang; Ma, Pengyu; Li, Hongqiang

    2017-09-29

    A high-channel-count bandstop graphene plasmonic filter based on ultracompact plasmonic structure is proposed in this paper. It consists of graphene waveguide side-coupled with a series of graphene filtering units. The study shows that the waveguide-resonator system performs a multiple plasmon induced transparency (PIT) phenomenon. By carefully adjusting the Fermi level of the filtering units, any two adjacent transmitted dips which belong to different PIT units can produce coherent coupling superposition enhancement. This property prevents the attenuation of the high-frequency transmission dips of multiple PIT and leads to an excellent bandstop filter with multiple channels. Specifically, the bandwidth and modulation depth of the filters can be flexibly adjusted by tuning the Fermi energy of the graphene waveguide. This ultracompact plasmonic structure contributes to the achievement of frequency division multiplexing systems for optical computing and communications in highly integrated optical circuits. © 2017 IOP Publishing Ltd.

  15. Density-near-zero using the acoustically induced transparency of a Fano acoustic resonator

    NASA Astrophysics Data System (ADS)

    Elayouch, A.; Addouche, M.; Farhat, M.; Amin, M.; Bağcı, H.; Khelif, A.

    2016-11-01

    We report experimental results of near-zero mass density involving an acoustic metamaterial supporting Fano resonance. For this, we designed and fabricated an acoustic resonator with two closely coupled modes and measured its transmission properties. Our study reveals that the phenomenon of acoustically induced transparency is accompanied by an effect of near-zero density. Indeed, the dynamic effective parameters obtained from experimental data show the presence of a frequency band where the effective mass density is close to zero, with high transmission levels reaching 0.7. Furthermore, we demonstrate that such effective parameters lead to wave guiding in a 90-degrees-bent channel. This kind of acoustic metamaterial can, therefore, give rise to acoustic functions like controlling the wavefront, which may lead to very promising applications in acoustic cloacking or imaging.

  16. Large Fizeau's light-dragging effect in a moving electromagnetically induced transparent medium

    PubMed Central

    Kuan, Pei-Chen; Huang, Chang; Chan, Wei Sheng; Kosen, Sandoko; Lan, Shau-Yu

    2016-01-01

    As one of the most influential experiments on the development of modern macroscopic theory from Newtonian mechanics to Einstein's special theory of relativity, the phenomenon of light dragging in a moving medium has been discussed and observed extensively in different types of systems. To have a significant dragging effect, the long duration of light travelling in the medium is preferred. Here we demonstrate a light-dragging experiment in an electromagnetically induced transparent cold atomic ensemble and enhance the dragging effect by at least three orders of magnitude compared with the previous experiments. With a large enhancement of the dragging effect, we realize an atom-based velocimeter that has a sensitivity two orders of magnitude higher than the velocity width of the atomic medium used. Such a demonstration could pave the way for motional sensing using the collective state of atoms in a room temperature vapour cell or solid state material. PMID:27694938

  17. Tunable multiple phase-coupled plasmon-induced transparencies in graphene metamaterials.

    PubMed

    Zeng, Chao; Cui, Yudong; Liu, Xueming

    2015-01-12

    We demonstrate the existence of multiple electromagnetically induced transparencies (EIT)-like spectral responses in graphene metamaterials consisting of a series of self-assembled graphene Fabry-Pérot (FP) cavities. By exploiting the graphene plasmon resonances and phase-coupling effects, the transfer matrix model is established to theoretically predict the EIT-like responses, and the calculated results coincide well with numerical simulations. It is found that high-contrast (~90%) multiple EIT-like windows are observed over a broad range of mid-infrared. Additionally, these optical responses can be efficiently tuned by altering the Fermi level in graphene and the separations of FP cavities. The proposed scheme paves the way toward control of the multiple EIT-like responses, enabling exploration of the on-chip multifunctional electro-optic devices including multi-channel-selective filters, sensors, and modulators.

  18. Large Fizeau's light-dragging effect in a moving electromagnetically induced transparent medium.

    PubMed

    Kuan, Pei-Chen; Huang, Chang; Chan, Wei Sheng; Kosen, Sandoko; Lan, Shau-Yu

    2016-10-03

    As one of the most influential experiments on the development of modern macroscopic theory from Newtonian mechanics to Einstein's special theory of relativity, the phenomenon of light dragging in a moving medium has been discussed and observed extensively in different types of systems. To have a significant dragging effect, the long duration of light travelling in the medium is preferred. Here we demonstrate a light-dragging experiment in an electromagnetically induced transparent cold atomic ensemble and enhance the dragging effect by at least three orders of magnitude compared with the previous experiments. With a large enhancement of the dragging effect, we realize an atom-based velocimeter that has a sensitivity two orders of magnitude higher than the velocity width of the atomic medium used. Such a demonstration could pave the way for motional sensing using the collective state of atoms in a room temperature vapour cell or solid state material.

  19. Large Fizeau's light-dragging effect in a moving electromagnetically induced transparent medium

    NASA Astrophysics Data System (ADS)

    Kuan, Pei-Chen; Huang, Chang; Chan, Wei Sheng; Kosen, Sandoko; Lan, Shau-Yu

    2016-10-01

    As one of the most influential experiments on the development of modern macroscopic theory from Newtonian mechanics to Einstein's special theory of relativity, the phenomenon of light dragging in a moving medium has been discussed and observed extensively in different types of systems. To have a significant dragging effect, the long duration of light travelling in the medium is preferred. Here we demonstrate a light-dragging experiment in an electromagnetically induced transparent cold atomic ensemble and enhance the dragging effect by at least three orders of magnitude compared with the previous experiments. With a large enhancement of the dragging effect, we realize an atom-based velocimeter that has a sensitivity two orders of magnitude higher than the velocity width of the atomic medium used. Such a demonstration could pave the way for motional sensing using the collective state of atoms in a room temperature vapour cell or solid state material.

  20. Coupled-resonator-induced transparency in two microspheres as the element of angular velocity sensing

    NASA Astrophysics Data System (ADS)

    Qian, Kun; Tang, Jun; Guo, Hao; Zhang, Wei; Liu, Jian-Hua; Liu, Jun; Xue, Chen-Yang; Zhang, Wen-Dong

    2016-11-01

    We proposed a two-coupled microsphere resonator structure as the element of angular velocity sensing under the Sagnac effect. We analyzed the theoretical model of the two coupled microspheres, and derived the coupled-resonator-induced transparency (CRIT) transfer function, the effective phase shift, and the group delay. Experiments were also carried out to demonstrate the CRIT phenomenon in the two-coupled microsphere resonator structure. We calculated that the group index of the two-coupled sphere reaches n g = 180.46, while the input light at a wavelength of 1550 nm. Project supported by the National Natural Science Foundation of China (Grant Nos. 51225504, 61171056, and 91123036) and the Program for the Top Young Academic Leaders of Higher Learning Institutions of Shanxi Province, China.

  1. Storage and retrieval of electromagnetic waves with orbital angular momentum via plasmon-induced transparency.

    PubMed

    Bai, Zhengyang; Xu, Datang; Huang, Guoxiang

    2017-01-23

    We propose a scheme to realize the storage and retrieval of high-dimensional electromagnetic waves with orbital angular momentum (OAM) via plasmon-induced transparency (PIT) in a metamaterial, which consists of an array of meta-atoms constructed by a metallic structure loaded with two varactors. We show that due to PIT effect the system allows the existence of shape-preserving dark-mode plasmonic polaritons, which are mixture of electromagnetic-wave modes and dark oscillatory modes of the meta-atoms and may carry various OAMs. We demonstrate that the slowdown, storage and retrieval of multi-mode electromagnetic waves with OAMs can be achieved through the active manipulation of a control field. Our work raises the possibility for realizing PIT-based spatial multi-mode memory of electromagnetic waves and is promising for practical application of information processing with large capacity by using room-temperature metamaterials.

  2. Magnetically Induced Optical Transparency on a Forbidden Transition in Strontium for Cavity-Enhanced Spectroscopy

    NASA Astrophysics Data System (ADS)

    Winchester, Matthew N.; Norcia, Matthew A.; Cline, Julia R. K.; Thompson, James K.

    2017-06-01

    In this Letter we realize a narrow spectroscopic feature using a technique that we refer to as magnetically induced optical transparency. A cold ensemble of 88Sr atoms interacts with a single mode of a high-finesse optical cavity via the 7.5 kHz linewidth, spin forbidden 1S0 to 3P1 transition. By applying a magnetic field that shifts two excited state Zeeman levels, we open a transmission window through the cavity where the collective vacuum Rabi splitting due to a single level would create destructive interference for probe transmission. The spectroscopic feature approaches the atomic transition linewidth, which is much narrower than the cavity linewidth, and is highly immune to the reference cavity length fluctuations that limit current state-of-the-art laser frequency stability.

  3. Goos-Hänchen shift in a standing-wave-coupled electromagnetically-induced-transparency medium

    NASA Astrophysics Data System (ADS)

    Zhang, Xiao-Jun; Wang, Hai-Hua; Liang, Zhi-Peng; Xu, Yan; Fan, Cun-Bo; Liu, Cheng-Zhi; Gao, Jin-Yue

    2015-03-01

    The Goos-Hänchen shift of the system composed by two cavity walls and an intracavity atomic sample is presented. The atomic sample is treated as a four-level double-Λ system, driven by the two counterpropagating coupling fields. The probe field experiences the discontinuous refractive index variation and is reflected. Moreover, under the phase-matching condition, the four-wave mixing effect based on electromagnetically induced transparency can cause effective reflection. The Goos-Hänchen shifts appear in both situations and are carefully investigated in this article. We refer to the first one with the incident and reflected light having identical wavelength as the linear Goos-Hänchen shift, and the second one with the reflection wavelength determined by the phase-matching condition as the nonlinear Goos-Hänchen shift. The differences between the two kinds of shifts, such as the incident angle range, conditions for the shift peaks, and controllability, are discussed.

  4. Electromagnetically induced transparency metamaterial based on spoof localized surface plasmons at terahertz frequencies.

    PubMed

    Liao, Zhen; Liu, Shuo; Ma, Hui Feng; Li, Chun; Jin, Biaobing; Cui, Tie Jun

    2016-06-09

    We numerically and experimentally demonstrate a plasmonic metamaterial whose unit cell is composed of an ultrathin metallic disk and four ultrathin metallic spiral arms at terahertz frequencies, which supports both spoof electric and magnetic localized surface plasmon (LSP) resonances. We show that the resonant wavelength is much larger than the size of the unit particle, and further find that the resonant wavelength is very sensitive to the particle's geometrical dimensions and arrangements. It is clearly illustrated that the magnetic LSP resonance exhibits strong dependence to the incidence angle of terahertz wave, which enables the design of metamaterials to achieve an electromagnetically induced transparency effect in the terahertz frequencies. This work opens up the possibility to apply for the surface plasmons in functional devices in the terahertz band.

  5. Laser-Induced Fluorescence Photogrammetry for Dynamic Characterization of Transparent and Aluminized Membrane Structures

    NASA Technical Reports Server (NTRS)

    Dorrington, Adrian A.; Jones, Thomas W.; Danehy, Paul M.; Pappa, Richard S.

    2003-01-01

    Photogrammetry has proven to be a valuable tool for static and dynamic profiling of membrane based inflatable and ultra-lightweight space structures. However, the traditional photogrammetric targeting techniques used for solid structures, such as attached retro-reflective targets and white-light dot projection, have some disadvantages and are not ideally suited for measuring highly transparent or reflective membrane structures. In this paper, we describe a new laser-induced fluorescence based target generation technique that is more suitable for these types of structures. We also present several examples of non-contact non-invasive photogrammetric measurements of laser-dye doped polymers, including the dynamic measurement and modal analysis of a 1m-by-1m aluminized solar sail style membrane.

  6. An electromagnetic induced transparency-like scheme for wireless power transfer using dielectric resonators

    NASA Astrophysics Data System (ADS)

    Elnaggar, Sameh Y.

    2017-02-01

    Similar to the hybridization of three atoms, three coupled resonators interact to form bonding, anti-bonding, and non-bonding modes. The non-bonding mode enables an electromagnetic induced transparency like transfer of energy. Here, the non-bonding mode, resulting from the strong electric coupling of two dielectric resonators and an enclosure, is exploited to show that it is feasible to transfer power over a distance comparable to the operating wavelength. In this scheme, the enclosure acts as a mediator. The strong coupling permits the excitation of the non-bonding mode with high purity. This approach is different from resonant inductive coupling, which works in the sub-wavelength regime. Optimal loads and the corresponding maximum efficiency are determined using two independent methods: Coupled Mode Theory and Circuit modelling. It is shown that, unlike resonant inductive coupling, the figure of merit depends on the enclosure quality and not on the load, which emphasizes the role of the enclosure as a mediator. Briefly after the input excitation is turned on, the energy in the receiver builds up via all coupled and spurious modes. As time elapses, all modes except the non-bonding cease to sustain. Due to the strong coupling between the dielectrics and the enclosure, such systems have unique properties such as high and uniform efficiency over large distances and minimal fringing fields. These properties suggest that electromagnetic induced transparency like schemes that rely on the use of dielectric resonators can be used to power autonomous systems inside an enclosure or find applications when exposure to the fields needs to be minimal. Finite Element computations are used to verify the theoretical predictions by determining the transfer efficiency, field profile, and coupling coefficients for two different systems. It is shown that the three resonators must be present for efficient power transfer; if one or more are removed, the transfer efficiency reduces

  7. Quantum phase gate based on electromagnetically induced transparency in optical cavities

    NASA Astrophysics Data System (ADS)

    Borges, Halyne S.; Villas-Bôas, Celso J.

    2016-11-01

    We theoretically investigate the implementation of a quantum controlled-phase gate in a system constituted by a single atom inside an optical cavity, based on the electromagnetically induced transparency effect. First we show that a probe pulse can experience a π phase shift due to the presence or absence of a classical control field. Considering the interplay of the cavity-EIT effect and the quantum memory process, we demonstrated a controlled-phase gate between two single photons. To this end, first one needs to store a (control) photon in the ground atomic states. In the following, a second (target) photon must impinge on the atom-cavity system. Depending on the atomic state, this second photon will be either transmitted or reflected, acquiring different phase shifts. This protocol can then be easily extended to multiphoton systems, i.e., keeping the control photon stored, it may induce phase shifts in several single photons, thus enabling the generation of multipartite entangled states. We explore the relevant parameter space in the atom-cavity system that allows the implementation of quantum controlled-phase gates using the recent technologies. In particular, we have found a lower bound for the cooperativity of the atom-cavity system which enables the implementation of phase shift on single photons. The induced shift on the phase of a photonic qubit and the controlled-phase gate between single photons, combined with optical devices, enable one to perform universal quantum computation.

  8. Active terahertz metamaterials based on liquid-crystal induced transparency and absorption

    NASA Astrophysics Data System (ADS)

    Yang, Lei; Fan, Fei; Chen, Meng; Zhang, Xuanzhou; Chang, Sheng-Jiang

    2017-01-01

    An active terahertz (THz) liquid crystal (LC) metamaterial has been experimentally investigated for THz wave modulation. Some interesting phenomena of resonance shifting, tunable electromagnetically induced transparency (EIT) and electromagnetically induced absorption (EIA) have been observed in the same device structure under different DC bias directions and different incident wave polarization directions by the THz time domain spectroscopy. Further theoretical studies indicate that these effects originate from interference and coupling between bright and dark mode components of elliptically polarized modes in the LC metamaterial, which are induced by the optical activity of LC alignment controllable by the electric field as well as the changes of LC refractive index. The LC layer is indeed a phase retarder and polarization converter that is controlled by the DC bias. The THz modulation depth of the analogs of EIT and EIA effects are 18.3 dB and 10.5 dB in their frequency band, respectively. Electrical control, large modulation depth and feasible integration of this LC device make it an ideal candidate for THz tunable filter, intensity modulator and spatial light modulator.

  9. Large protein-induced dipoles for a symmetric carotenoid in a photosynthetic antenna complex.

    PubMed

    Gottfried, D S; Steffen, M A; Boxer, S G

    1991-02-08

    Unusually large electric field effects have been measured for the absorption spectra of carotenoids (spheroidene) in the B800-850 light-harvesting complex from the photosynthetic bacterium Rhodobacter sphaeroides. Quantitative analysis shows that the difference in the permanent dipole moment between the ground state and excited states in this protein complex is substantially larger than for pure spheroidene extracted from the protein. The results demonstrate the presence of a large perturbation on the electronic structure of this nearly symmetric carotenoid due to the organized environment in the protein. This work also provides an explanation for the seemingly anomalous dependence of carotenoid band shifts on transmembrane potential and a generally useful approach for calibrating electric field-sensitive dyes that are widely used to probe potentials in biological systems.

  10. Radiating dipole model of interference induced in spacecraft circuitry by surface discharges

    NASA Technical Reports Server (NTRS)

    Metz, R. N.

    1984-01-01

    Spacecraft in geosynchronous orbit can be charged electrically to high voltages by interaction with the space plasma. Differential charging of spacecraft surfaces leads to arc and blowoff discharging. The discharges are thought to upset interior, computer-level circuitry. In addition to capacitive or electrostatic effects, significant inductive and less significant radiative effects of these discharges exist and can be modeled in a dipole approximation. Flight measurements suggest source frequencies of 5 to 50 MHz. Laboratory tests indicate source current strengths of several amperes. Electrical and magnetic fields at distances of many centimeters from such sources can be as large as tens of volts per meter and meter squared, respectively. Estimates of field attenuation by spacecraft walls and structures suggest that interior fields may be appreciable if electromagnetic shielding is much thinner than about 0.025 mm (1 mil). Pickup of such fields by wires and cables interconnecting circuit components could be a source of interference signals of several volts amplitude.

  11. Transient birefringence of liquids induced by terahertz electric-field torque on permanent molecular dipoles

    PubMed Central

    Sajadi, Mohsen; Wolf, Martin; Kampfrath, Tobias

    2017-01-01

    Collective low-frequency molecular motions have large impact on chemical reactions and structural relaxation in liquids. So far, these modes have mostly been accessed indirectly by off-resonant optical pulses. Here, we provide evidence that intense terahertz (THz) pulses can resonantly excite reorientational-librational modes of aprotic and strongly polar liquids through coupling to the permanent molecular dipole moments. We observe a significantly enhanced response because the transient optical birefringence is up to an order of magnitude higher than obtained with optical excitation. Frequency-dependent measurements and a simple analytical model indicate that the enhancement arises from resonantly driven librations and their coupling to reorientational motion, assisted by the pump field and/or a cage translational mode. Our results open up the path to applications such as efficient molecular alignment, enhanced transient Kerr signals and systematic resonant nonlinear THz spectroscopy of the coupling between intermolecular modes in liquids. PMID:28393836

  12. Transient birefringence of liquids induced by terahertz electric-field torque on permanent molecular dipoles.

    PubMed

    Sajadi, Mohsen; Wolf, Martin; Kampfrath, Tobias

    2017-04-10

    Collective low-frequency molecular motions have large impact on chemical reactions and structural relaxation in liquids. So far, these modes have mostly been accessed indirectly by off-resonant optical pulses. Here, we provide evidence that intense terahertz (THz) pulses can resonantly excite reorientational-librational modes of aprotic and strongly polar liquids through coupling to the permanent molecular dipole moments. We observe a significantly enhanced response because the transient optical birefringence is up to an order of magnitude higher than obtained with optical excitation. Frequency-dependent measurements and a simple analytical model indicate that the enhancement arises from resonantly driven librations and their coupling to reorientational motion, assisted by the pump field and/or a cage translational mode. Our results open up the path to applications such as efficient molecular alignment, enhanced transient Kerr signals and systematic resonant nonlinear THz spectroscopy of the coupling between intermolecular modes in liquids.

  13. Transient birefringence of liquids induced by terahertz electric-field torque on permanent molecular dipoles

    NASA Astrophysics Data System (ADS)

    Sajadi, Mohsen; Wolf, Martin; Kampfrath, Tobias

    2017-04-01

    Collective low-frequency molecular motions have large impact on chemical reactions and structural relaxation in liquids. So far, these modes have mostly been accessed indirectly by off-resonant optical pulses. Here, we provide evidence that intense terahertz (THz) pulses can resonantly excite reorientational-librational modes of aprotic and strongly polar liquids through coupling to the permanent molecular dipole moments. We observe a significantly enhanced response because the transient optical birefringence is up to an order of magnitude higher than obtained with optical excitation. Frequency-dependent measurements and a simple analytical model indicate that the enhancement arises from resonantly driven librations and their coupling to reorientational motion, assisted by the pump field and/or a cage translational mode. Our results open up the path to applications such as efficient molecular alignment, enhanced transient Kerr signals and systematic resonant nonlinear THz spectroscopy of the coupling between intermolecular modes in liquids.

  14. Quantum Nonlinear Hall Effect Induced by Berry Curvature Dipole in Time-Reversal Invariant Materials.

    PubMed

    Sodemann, Inti; Fu, Liang

    2015-11-20

    It is well known that a nonvanishing Hall conductivity requires broken time-reversal symmetry. However, in this work, we demonstrate that Hall-like currents can occur in second-order response to external electric fields in a wide class of time-reversal invariant and inversion breaking materials, at both zero and twice the driving frequency. This nonlinear Hall effect has a quantum origin arising from the dipole moment of the Berry curvature in momentum space, which generates a net anomalous velocity when the system is in a current-carrying state. The nonlinear Hall coefficient is a rank-two pseudotensor, whose form is determined by point group symmetry. We discus optimal conditions to observe this effect and propose candidate two- and three-dimensional materials, including topological crystalline insulators, transition metal dichalcogenides, and Weyl semimetals.

  15. Short-pulse cross-phase modulation in an electromagnetically-induced-transparency medium

    NASA Astrophysics Data System (ADS)

    Feizpour, Amir; Dmochowski, Greg; Steinberg, Aephraim M.

    2016-01-01

    Electromagnetically induced transparency (EIT) has been proposed as a way to greatly enhance cross-phase modulation, with the possibility of leading to few-photon-level optical nonlinearities [Schmidt and Imamoglu, Opt. Lett. 21, 1936 (1996), 10.1364/OL.21.001936]. This enhancement grows as the transparency window width, ΔEIT, is narrowed. Decreasing ΔEIT, however, has been shown to increase the response time of the nonlinear medium. This suggests that, for a given pulse duration, the nonlinearity would diminish once the window width became narrower than this pulse bandwidth. We show that this is not the case: the peak phase shift saturates but does not decrease. We show that in the regimes of most practical interest—narrow EIT windows perturbed by short signal pulses—the enhancement offered by EIT is not only in the magnitude of the nonlinear phase shift but also in its increased duration. That is, for the case of signal pulses much shorter (temporally) than the inverse EIT bandwidth, the narrow window serves to prolong the effect of the passing signal pulse, leading to an integrated phase shift that grows linearly with 1 /ΔEIT ; this continued growth of the integrated phase shift improves the detectability of the phase shift, in principle, without bound. For many purposes, it is this detectability which is of more interest than the absolute magnitude of the peak phase shift. We present analytical expressions based on a linear time-invariant model that accounts for the temporal behavior of the cross-phase modulation for several parameter ranges of interest. We conclude that in order to optimize the detectability of the EIT-based cross-phase shift, one should use the narrowest possible EIT window and a signal pulse that is as broadband as the excited-state linewidth and detuned by half a linewidth.

  16. Precision Mass Sensing by Tunable Double Optomechanically Induced Transparency with Squeezed Field in a Coupled Optomechanical System

    NASA Astrophysics Data System (ADS)

    Wang, Qiong; Li, Wen-Juan

    2017-04-01

    We present a scheme for all-optical precision mass sensing with squeezed field in a system consisting of an optomechanical cavity coupled to a charged nanomechanical resonator (NAMR) in terms of tunable double optomechanically induced transparency (OMIT) . We demonstrate that the accreted mass landing on NAMR can be achieved by measuring the splitting of the two transparency windows of the double OMIT. Moreover, our work shows this scheme for the quantized fields can be robust against temperature and cavity decay in somehow. Specifically, the precision measurement is from the noise spectrum, for these reasons, our scheme may provide a new paradigm for precision measurement based on the noise in the optomechanical system.

  17. Plasmon-induced transparency in metamaterials: Active near field coupling between bright superconducting and dark metallic mode resonators

    NASA Astrophysics Data System (ADS)

    Cao, Wei; Singh, Ranjan; Zhang, Caihong; Han, Jiaguang; Tonouchi, Masayoshi; Zhang, Weili

    2013-09-01

    Structured plasmonic metamaterial devices offer the design flexibility to be size scaled for operation across the electromagnetic spectrum and are extremely attractive for generating electromagnetically induced transparency and slow-light behaviors via coupling of bright and dark subwavelength resonators. Here, we experimentally demonstrate a thermally active superconductor-metal coupled resonator based hybrid terahertz metamaterial on a sapphire substrate that shows tunable transparency and slow light behavior as the metamaterial chip is cooled below the high-temperature superconducting phase transition temperature. This hybrid metamaterial opens up the avenues for designing micro-sized active circuitry with switching, modulation, and "slowing down terahertz light" capabilities.

  18. Flash-Induced Self-Limited Plasmonic Welding of Silver Nanowire Network for Transparent Flexible Energy Harvester.

    PubMed

    Park, Jung Hwan; Hwang, Geon-Tae; Kim, Shinho; Seo, Jeongmin; Park, Hong-Jin; Yu, Kyoungsik; Kim, Taek-Soo; Lee, Keon Jae

    2017-02-01

    The outstanding performance (sheet resistance of 5 Ω sq(-1) at transmittance of 90%) and strongly adhesive (30.7 J m(-2) ) silver nanowires (AgNWs) are fabricated using flash-induced plasmonic welding (FPW) based on theoretical research of photothermal interactions. The FPW-processed AgNWs are utilized as electrodes of a transparent flexible energy harvester, and this device exhibits excellent transmittance and high electric output performance. The FPW methodology provides a high-tech solution for transparent flexible electronics.

  19. Precision Mass Sensing by Tunable Double Optomechanically Induced Transparency with Squeezed Field in a Coupled Optomechanical System

    NASA Astrophysics Data System (ADS)

    Wang, Qiong; Li, Wen-Juan

    2017-01-01

    We present a scheme for all-optical precision mass sensing with squeezed field in a system consisting of an optomechanical cavity coupled to a charged nanomechanical resonator (NAMR) in terms of tunable double optomechanically induced transparency (OMIT) . We demonstrate that the accreted mass landing on NAMR can be achieved by measuring the splitting of the two transparency windows of the double OMIT. Moreover, our work shows this scheme for the quantized fields can be robust against temperature and cavity decay in somehow. Specifically, the precision measurement is from the noise spectrum, for these reasons, our scheme may provide a new paradigm for precision measurement based on the noise in the optomechanical system.

  20. Bound states for an induced electric dipole in the presence of an azimuthal magnetic field and a disclination

    SciTech Connect

    Bakke, K.

    2010-09-15

    Based on the Wei-Han-Wei setup [H. Wei, R. Han, and X. Wei, Phys. Rev. Lett. 75, 2071 (1995)], where a neutral particle with an induced electric dipole moment interacts with a configuration of crossed electric and magnetic fields, in this paper we study the bound states that arise when we change the Wei-Han-Wei field configuration and consider a field configuration of crossed azimuthal magnetic field and a radial electric field. Moreover, we consider here a spin-half neutral particle and the presence of a linear topological defect called disclination. We obtain the bound states in two distinct cases: in the first case, we consider that the wave function of the neutral particle is well-behaved at the origin and vanishes at the asymptotic limit; in the second case, we consider the neutral particle confined to a parabolic potential like a quantum dot.

  1. An electromagnetic modulator based on electrically controllable metamaterial analogue to electromagnetically induced transparency.

    PubMed

    Fan, Yuancheng; Qiao, Tong; Zhang, Fuli; Fu, Quanhong; Dong, Jiajia; Kong, Botao; Li, Hongqiang

    2017-01-16

    Electromagnetically induced transparency (EIT) is a promising technology for the enhancement of light-matter interactions, and recent demonstrations of the EIT analogue realized in artificial micro-structured medium have remarkably reduced the extreme requirement for experimental observation of EIT spectrum. In this paper, we propose to electrically control the EIT-like spectrum in a metamaterial as an electromagnetic modulator. A diode acting as a tunable resistor is loaded in the gap of paired wires to inductively tune the magnetic resonance, which induces remarkable modulation on the EIT-like spectrum through the metamaterial sample. The experimental measurements confirmed that the prediction of electromagnetic modulation in three narrow bands on the EIT-like spectrum, and a modulation contrast of up to 31 dB was achieved on the transmission through the metamaterial. Our results may facilitate the study on active/dynamical technology in translational metamaterials, which connect extraordinary manipulations on the flow of light in metamaterials, e.g., the exotic EIT, and practical applications in industry.

  2. An electromagnetic modulator based on electrically controllable metamaterial analogue to electromagnetically induced transparency

    NASA Astrophysics Data System (ADS)

    Fan, Yuancheng; Qiao, Tong; Zhang, Fuli; Fu, Quanhong; Dong, Jiajia; Kong, Botao; Li, Hongqiang

    2017-01-01

    Electromagnetically induced transparency (EIT) is a promising technology for the enhancement of light-matter interactions, and recent demonstrations of the EIT analogue realized in artificial micro-structured medium have remarkably reduced the extreme requirement for experimental observation of EIT spectrum. In this paper, we propose to electrically control the EIT-like spectrum in a metamaterial as an electromagnetic modulator. A diode acting as a tunable resistor is loaded in the gap of paired wires to inductively tune the magnetic resonance, which induces remarkable modulation on the EIT-like spectrum through the metamaterial sample. The experimental measurements confirmed that the prediction of electromagnetic modulation in three narrow bands on the EIT-like spectrum, and a modulation contrast of up to 31 dB was achieved on the transmission through the metamaterial. Our results may facilitate the study on active/dynamical technology in translational metamaterials, which connect extraordinary manipulations on the flow of light in metamaterials, e.g., the exotic EIT, and practical applications in industry.

  3. Active multiple plasmon-induced transparencies with detuned asymmetric multi-rectangle resonators

    NASA Astrophysics Data System (ADS)

    Liu, Dongdong; Wang, Jicheng; Lu, Jian

    2016-11-01

    The phenomenon of plasmon-induced transparency (PIT) is realized in surface plasmon polariton waveguide at the visible and near-infrared ranges. By adding one and two resonant cavities, the PIT peak(s) was (were) achieved due to destructive interference between the side-coupled rectangle cavity and the bus waveguide. The proposed structures were demonstrated by the finite element method. The simulation results showed that for three rectangle resonators system, not only can we manipulate each single PIT window, but also the double PIT windows simultaneously by adjusting one of the geometrical parameters of the system; for four rectangle resonators system, by changing the widths, the lengths and the refractive index of three cavities simultaneously, we would realize treble PIT peaks and induce an off-to-on PIT optical response. Our novel plasmonic structures and the findings pave the way for new design and engineering of highly integrated optical circuit such as nanoscale optical switching, nanosensor and wavelength-selecting nanostructure.

  4. An electromagnetic modulator based on electrically controllable metamaterial analogue to electromagnetically induced transparency

    PubMed Central

    Fan, Yuancheng; Qiao, Tong; Zhang, Fuli; Fu, Quanhong; Dong, Jiajia; Kong, Botao; Li, Hongqiang

    2017-01-01

    Electromagnetically induced transparency (EIT) is a promising technology for the enhancement of light-matter interactions, and recent demonstrations of the EIT analogue realized in artificial micro-structured medium have remarkably reduced the extreme requirement for experimental observation of EIT spectrum. In this paper, we propose to electrically control the EIT-like spectrum in a metamaterial as an electromagnetic modulator. A diode acting as a tunable resistor is loaded in the gap of paired wires to inductively tune the magnetic resonance, which induces remarkable modulation on the EIT-like spectrum through the metamaterial sample. The experimental measurements confirmed that the prediction of electromagnetic modulation in three narrow bands on the EIT-like spectrum, and a modulation contrast of up to 31 dB was achieved on the transmission through the metamaterial. Our results may facilitate the study on active/dynamical technology in translational metamaterials, which connect extraordinary manipulations on the flow of light in metamaterials, e.g., the exotic EIT, and practical applications in industry. PMID:28091539

  5. Visible-light-induced instability in amorphous metal-oxide based TFTs for transparent electronics

    SciTech Connect

    Ha, Tae-Jun

    2014-10-15

    We investigate the origin of visible-light-induced instability in amorphous metal-oxide based thin film transistors (oxide-TFTs) for transparent electronics by exploring the shift in threshold voltage (V{sub th}). A large hysteresis window in amorphous indium-gallium-zinc-oxide (a-IGZO) TFTs possessing large optical band-gap (≈3 eV) was observed in a visible-light illuminated condition whereas no hysteresis window was shown in a dark measuring condition. We also report the instability caused by photo irradiation and prolonged gate bias stress in oxide-TFTs. Larger V{sub th} shift was observed after photo-induced stress combined with a negative gate bias than the sum of that after only illumination stress and only negative gate bias stress. Such results can be explained by trapped charges at the interface of semiconductor/dielectric and/or in the gate dielectric which play a role in a screen effect on the electric field applied by gate voltage, for which we propose that the localized-states-assisted transitions by visible-light absorption can be responsible.

  6. Crack-induced Ag nanowire networks for transparent, stretchable, and highly sensitive strain sensors.

    PubMed

    Lee, Chan-Jae; Park, Keum Hwan; Han, Chul Jong; Oh, Min Suk; You, Banseok; Kim, Young-Seok; Kim, Jong-Woong

    2017-08-11

    Crack-based strain sensor systems have been known for its high sensitivity, but suffer from the small fracture strain of the thin metal films employed in the sensor which results in its negligible stretchability. Herein, we fabricated a transparent (>90% at 550 nm wavelength), stretchable (up to 100%), and sensitive (gauge factor (GF) of 30 at 100% strain) strain gauge by depositing an encapsulated crack-induced Ag nanowire (AgNW) network on a hydroxylated poly(dimethylsiloxane) (PDMS) film. Stretching the encapsulated AgNWs/PDMS resulted in the formation of a percolation network of nanowire ligaments with abundant percolation paths. The encapsulating polymer was designed to adhere strongly to both the AgNW and PDMS. The improved adhesion ensured the resistance of the crack-induced network of AgNWs varied reversibly, stably, and sensitively when stretched and released, at strains of up to 100%. The developed sensor successfully detected human motions when applied to the skin.

  7. Graphene-epoxy flexible transparent capacitor obtained by graphene-polymer transfer and UV-induced bonding.

    PubMed

    Sangermano, Marco; Chiolerio, Alessandro; Veronese, Giulio Paolo; Ortolani, Luca; Rizzoli, Rita; Mancarella, Fulvio; Morandi, Vittorio

    2014-02-01

    A new approach is reported for the preparation of a graphene-epoxy flexible transparent capacitor obtained by graphene-polymer transfer and UV-induced bonding. SU8 resin is employed for realizing a well-adherent, transparent, and flexible supporting layer. The achieved transparent graphene/SU8 membrane presents two distinct surfaces: one homogeneous conductive surface containing a graphene layer and one dielectric surface typical of the epoxy polymer. Two graphene/SU8 layers are bonded together by using an epoxy photocurable formulation based on epoxy resin. The obtained material showed a stable and clear capacitive behavior. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Effect of electron heating on self-induced transparency in relativistic-intensity laser-plasma interactions.

    PubMed

    Siminos, E; Grech, M; Skupin, S; Schlegel, T; Tikhonchuk, V T

    2012-11-01

    The effective increase of the critical density associated with the interaction of relativistically intense laser pulses with overcritical plasmas, known as self-induced transparency, is revisited for the case of circular polarization. A comparison of particle-in-cell simulations to the predictions of a relativistic cold-fluid model for the transparency threshold demonstrates that kinetic effects, such as electron heating, can lead to a substantial increase of the effective critical density compared to cold-fluid theory. These results are interpreted by a study of separatrices in the single-electron phase space corresponding to dynamics in the stationary fields predicted by the cold-fluid model. It is shown that perturbations due to electron heating exceeding a certain finite threshold can force electrons to escape into the vacuum, leading to laser pulse propagation. The modification of the transparency threshold is linked to the temporal pulse profile, through its effect on electron heating.

  9. Alcohol-soluble interfacial fluorenes for inverted polymer solar cells: sequence induced spatial conformation dipole moment.

    PubMed

    Chen, Lie; Liu, Xiangfu; Wei, Yingkai; Wu, Feiyan; Chen, Yiwang

    2016-01-21

    Three fluorene-based alcohol-soluble organic small molecule electrolytes (SMEs) with different conjugated backbones, namely, TFTN-Br, FTFN-Br and FTTFN-Br, were designed as cathode interfacial layers for inverted polymer solar cells (i-PSCs). The insertion of SMEs to the ITO/active layer interfaces effectively lowered the energy barrier for electron transport and improved the inherent compatibility between the hydrophilic ITO and hydrophobic active layers. Due to these advantages, the device based on poly(3-hexylthiophene) (P3HT):(6,6)-phenyl-C61 butyric acid methyl ester (PC61BM) with TFTN-Br as the cathode interfacial layer achieved an improved power conversion efficiency (PCE) of 3.8%, which is a 26% improvement when compared to the standard device comprising ZnO cathode interfacial layers (PCE = 3.0%). Devices with FTFN-Br and FTTFN-Br also showed an improved PCE of 3.1% and 3.5%, respectively. The variation in device performance enhancement was found to be primarily correlated with the different conformation of their assembly onto the electrode caused by the joint sequence of the polar group of the SMEs, consequently impacting the dipole moment and interface morphology. In addition, introducing SMEs as the cathode interfacial layer also produced devices with long-term stability.

  10. Electric dipole moment searches: Effect of linear electric field frequency shifts induced in confined gases

    SciTech Connect

    Barabanov, A. L.; Golub, R.; Lamoreaux, S. K.

    2006-11-15

    The search for particle electric dipole moments (EDM's) represents a most promising way to search for physics beyond the standard model. A number of groups are planning a new generation of experiments using stored gases of various kinds. In order to achieve the target sensitivities it will be necessary to deal with the systematic error resulting from the interaction of the well-known v-vectorxE-vector field with magnetic field gradients which is often referred to as the geometric phase effect [E. D. Commins, Am. J. Phys. 59, 1077 (1991); J. M. Pendlebury et al., Phys. Rev. A 70, 032102 (2004)]. This interaction produces a frequency shift linear in the electric field, mimicking an EDM. In this work we introduce an analytic form for the velocity autocorrelation function which determines the velocity-position correlation function which in turn determines the behavior of the frequency shift [S. K. Lamoreaux and R. Golub, Phys. Rev A 71, 032104 (2005)] and show how it depends on the operating conditions of the experiment. We also discuss some additional issues.

  11. Shallow-trap-induced positive absorptive two-beam coupling 'gain' and light-induced transparency in nominally undoped barium titanate

    NASA Technical Reports Server (NTRS)

    Garrett, M. H.; Tayebati, P.; Chang, J. Y.; Jenssen, H. P.; Warde, C.

    1992-01-01

    The asymmetry of beam coupling with respect to the orientation of the polar axis in a nominally undoped barium titanate crystal is used to determine the electro-optic and absorptive 'gain' in the usual beam-coupling geometry. For small grating wave vectors, the electrooptic coupling vanishes but the absorptive coupling remains finite and positive. Positive absorptive coupling at small grating wave vectors is correlated with the light-induced transparency of the crystal described herein. The intensity and grating wave vector dependence of the electrooptic and absorptive coupling, and the light-induced transparency are consistent with a model incorporating deep and shallow levels.

  12. Shallow-trap-induced positive absorptive two-beam coupling 'gain' and light-induced transparency in nominally undoped barium titanate

    NASA Technical Reports Server (NTRS)

    Garrett, M. H.; Tayebati, P.; Chang, J. Y.; Jenssen, H. P.; Warde, C.

    1992-01-01

    The asymmetry of beam coupling with respect to the orientation of the polar axis in a nominally undoped barium titanate crystal is used to determine the electro-optic and absorptive 'gain' in the usual beam-coupling geometry. For small grating wave vectors, the electrooptic coupling vanishes but the absorptive coupling remains finite and positive. Positive absorptive coupling at small grating wave vectors is correlated with the light-induced transparency of the crystal described herein. The intensity and grating wave vector dependence of the electrooptic and absorptive coupling, and the light-induced transparency are consistent with a model incorporating deep and shallow levels.

  13. Extensive Measurements of Vibration-Induced Permanent Electric Dipole Moments of Methane

    NASA Astrophysics Data System (ADS)

    Okuda, Shoko; Sasada, Hiroyuki

    2016-06-01

    A methane molecule (CH_4) has a permanent electric dipole moment (PEDM) in the excited state of the triply-degenerate vibrational modes. The rotational dependence of the PEDM was reported in the 2νb{3} band. However, in the νb{3} band, it was only determined on the P(7) E transition which fortunately lies in the tunable range of a 3.4 μm He-Ne laser. We have developed a mid-infrared broadband sub-Doppler resolution spectrometer consisting of a difference-frequency-generation source and an optical frequency comb linked to International Atomic Time. This spectrometer enables us to measure the Stark effects of 20 transitions in the νb{3} band of methane from 87.7 to 92.8 THz (2927˜3095 wn). The observed linewidth is 0.5 MHz, and the frequency scale is absolutely calibrated. The figure depicts the Stark modulation spectrum of the P(4) E transition. The applied DC electric field was 3.5 kV/cm. We determined Stark coefficients with a relative uncertainty of 1 %. Our goal is to reveal the rotational dependence of the PEDM. For this end, we yield molecular constants which reproduce the transition frequencies by a least-square method and determine the mixing of the wave functions. M. Mizushima and P. Venkateswarlu, J. Chem. Phys. 21, 705 (1953) K. Uehara, K. Sakurai and K. Shimoda, J. Phys. Soc. Jpn. 26, 1018 (1969) H. Sasada, K. Suzumura and C. Ishibashi, J. Chem. Phys. 105, 9027 (1996)

  14. Investigation and optimization of intraband electromagnetically induced transparency in strained InAs quantum dot/wetting layer structures

    NASA Astrophysics Data System (ADS)

    Parvizi, R.; Rezaei, G.

    2016-01-01

    In this work, effects of the shape and size on the optical properties and optimization of the intersubband electromagnetically induced transparency in the Infra-red region of three-dimensional strained truncated pyramid-shaped InAs/GaAs quantum dot (QD) were investigated in detail. More precisely, within the density matrix approach, the probe absorption and group velocity along with the refractive index of the medium were studied with respect to their dependence on the dephasing rates and the Rabi frequencies of the probe and coupling fields for different QD heights and wetting layer (WL) thicknesses. It is found that the slow-down factors, group index, and absorption coefficient are inversely proportional to the width of the transparency window and proportional to the depth of the transparency window. The optimized transparency window can be achieved by varying the dot height and the WL thickness such that the tall dots with thin WL thickness induce significant enhancements at a fixed resonant peak position of Rabi frequency of the coupling field. The physical reasons behind these interesting phenomena were also explained based on the polarized features of intersubband transitions.

  15. Unidirectional plasmonically induced transparency behavior in a compact graphene-based waveguide

    NASA Astrophysics Data System (ADS)

    Zhang, Zhengren; Long, Yang; Zang, Xiaofei

    2017-07-01

    A graphene-based waveguide structure is proposed to achieve a unidirectional plasmonically induced transparency (PIT) behavior. In this structure, a standing-wave cavity can be formed in the graphene waveguide by controlling the Fermi energy at a different part of the graphene. Two resonant graphene ribbons are placed at the node and antinode of the standing-wave cavity field, respectively. Its corresponding optical response coming from different incident sides show a unidirectional PIT behavior. This is because the excited bright resonant graphene ribbon located at antinode inhibits the field strength on its downstream side and causes the field redistribution on its upstream side. When the wave propagates along the sequence node-antinode, the redistribution field will excite the dark resonant graphene ribbon, such that both ribbons couple coherently and the PIT behavior appears. In contrast, when the wave propagates along the sequence antinode-node, the dark resonant graphene ribbon remains dark, and no PIT appears. Our results may benefit novel nonreciprocal devices in the future.

  16. Observation of optically induced transparency effect in silicon nanophotonic wires with graphene

    NASA Astrophysics Data System (ADS)

    Yu, Longhai; Zheng, Jiajiu; Dai, Daoxin; He, Sailing

    2014-03-01

    Graphene, a well-known two-dimensional sheet of carbon atoms in a honeycomb structure, has many unique and fascinating properties in optoelectronics and photonics. Integration of graphene on silicon nanophotonic wires is a promising approach to enhance light-graphene interactions. In this paper, we demonstrate on-chip silicon nanophotonic wires covered by graphene with CMOS-compatible fabrication processes. Under the illumination of pump light on the graphene sheet, a loss reduction of silicon nanophotonic wires, which is called optically induced transparency (OIT) effect, is observed over a broad wavelength range for the first time. The pump power required to generate the OIT effect is as low as ~0.1mW and the corresponding power density is about 2×103mW/cm2, which is significantly different from the saturated absorption effect of graphene reported previously. The extremely low power density implies a new mechanism for the present OIT effect, which will be beneficial to realize silicon on-chip all-optical controlling in the future. It also suggests a new and efficient approach to tune the carrier concentration (doping level) in graphene optically.

  17. Controlled Electromagnetically Induced Transparency and Fano Resonances in Hybrid BEC-Optomechanics

    PubMed Central

    Yasir, Kashif Ammar; Liu, Wu-Ming

    2016-01-01

    Cavity-optomechanics, a tool to manipulate mechanical effects of light to couple optical field with other physical objects, is the subject of increasing investigations, especially with regards to electromagnetically induced transparency (EIT). EIT, a result of Fano interference among different atomic transition levels, has acquired a significant importance in many areas of physics, such as atomic physics and quantum optics. However, controllability of such multi-dimensional systems has remained a crucial issue. In this report, we investigate the controllability of EIT and Fano resonances in hybrid optomechanical system composed of cigar-shaped Bose-Einstein condensate (BEC), trapped inside high-finesse Fabry-Pérot cavity with one vibrational mirror, driven by a single mode optical field and a transverse pump field. The transverse field is used to control the phenomenon of EIT. It is detected that the strength of transverse field is not only efficiently amplifying or attenuating out-going optical mode but also providing an opportunity to enhance the strength of Fano-interactions which leads to the amplification of EIT-window. To observe these phenomena in laboratory, we suggest a certain set of experimental parameters. The results provide a route for tunable manipulation of optical phenomena, like EIT, which could be a significant step in quantum engineering. PMID:26955789

  18. Nanosecond laser-induced damage of transparent conducting ITO film at 1064nm

    NASA Astrophysics Data System (ADS)

    Yoo, Jae-Hyuck; Adams, John J.; Menor, Marlon G.; Olson, Tammy Y.; Lee, Jonathan R. I.; Samanta, Amit; Bude, Jeff; Elhadj, Selim

    2016-12-01

    Transparent conducting films with superior laser damage performance have drawn intense interests toward optoelectronic applications under high energy density environment. In order to make optoelectronic applications with high laser damage performance, a fundamental understanding of damage mechanisms of conducting films is crucial. In this study, we performed laser damage experiments on tin-doped indium oxide films (ITO, Bandgap = 4.0 eV) using a nanosecond (ns) pulse laser (1064 nm) and investigated the underlying physical damage mechanisms. Single ns laser pulse irradiation on ITO films resulted in common thermal degradation features such as melting and evaporation although the laser photon energy (1.03 eV, 1064 nm) was smaller than the bandgap. Dominant laser energy absorption of the ITO film is attributed to free carriers due to degenerate doping. Upon multi-pulse irradiation on the film, damage initiation and growth were observed at lower laser influences, where no apparent damage was formed upon single pulse, suggesting a laser-induced incubation effect.

  19. Microplasma generation by slow microwave in an electromagnetically induced transparency-like metasurface

    NASA Astrophysics Data System (ADS)

    Tamayama, Yasuhiro; Sakai, Osamu

    2017-02-01

    Microplasma generation using microwaves in an electromagnetically induced transparency (EIT)-like metasurface composed of two types of radiatively coupled cut-wire resonators with slightly different resonance frequencies is investigated. A microplasma is generated in either of the gaps of the cut-wire resonators as a result of strong enhancement of the local electric field associated with resonance and slow microwave effects. The threshold microwave power for plasma ignition is found to reach a minimum at the EIT-like transmission peak frequency, where the group index is maximized. A pump-probe measurement of the metasurface reveals that the transmission properties can be significantly varied by varying the properties of the generated microplasma near the EIT-like transmission peak frequency and the resonance frequency. The electron density of the microplasma is roughly estimated to be of order 1 × 10 10 cm - 3 for a pump power of 15.8 W by comparing the measured transmission spectrum for the probe wave with the numerically calculated spectrum. In the calculation, we assumed that the plasma is uniformly generated in the resonator gap, that the electron temperature is 2 eV, and that the elastic scattering cross section is 20 × 10 - 16 cm 2 .

  20. Plasmonic metamaterial for electromagnetically induced transparency analogue and ultra-high figure of merit sensor

    NASA Astrophysics Data System (ADS)

    Wu, Dong; Liu, Yumin; Yu, Li; Yu, Zhongyuan; Chen, Lei; Li, Ruifang; Ma, Rui; Liu, Chang; Zhang, Jinqiannan; Ye, Han

    2017-03-01

    In this work, using finite-difference time-domain method, we propose and numerically demonstrate a novel way to achieve electromagnetically induced transparency (EIT) phenomenon in the reflection spectrum by stacking two different types of coupling effect among different elements of the designed metamaterial. Compared with the conventional EIT-like analogues coming from only one type of coupling effect between bright and dark meta-atoms on the same plane, to our knowledge the novel approach is the first to realize the optically active and precise control of the wavelength position of EIT-like phenomenon using optical metamaterials. An on-to-off dynamic control of the EIT-like phenomenon also can be achieved by changing the refractive index of the dielectric substrate via adjusting an optical pump pulse. Furthermore, in near infrared region, the metamaterial structure can be operated as an ultra-high resolution refractive index sensor with an ultra-high figure of merit (FOM) reaching 3200, which remarkably improve the FOM value of plasmonic refractive index sensors. The novel approach realizing EIT-like spectral shape with easy adjustment to the working wavelengths will open up new avenues for future research and practical application of active plasmonic switch, ultra-high resolution sensors and active slow-light devices.

  1. Orthogonality breaking induces extraordinary single-mode transparency in an elaborate waveguide with wall corrugations

    PubMed Central

    Tao, Zhi-Yong; Fan, Ya-Xian

    2014-01-01

    Orthogonality plays a fundamental role in various mathematical theorems and in physics. The orthogonal eigenfunctions that represent the intrinsic motions of various physical systems can also be regarded as transverse wave modes in a straight waveguide. Because of their orthogonality, these modes propagate independently, without mutual interference. When the wall separation fluctuates, the former mode orthogonality is destroyed because of the change in the Euclidean space of the system. Here, we experimentally demonstrate the extraordinary single-mode transparency that arises as a result of the intense mode interference induced by orthogonality breaking in a waveguide with a varying cross section. A mode diagram is also introduced to illuminate these mode interactions. In particular, measurements of the transverse field distributions indicate that a three-mode interaction leads to a single high-order mode that penetrates through the lower-mode bandgaps when the wall period is carefully selected. The observation of Bessel-like transverse distributions is promising for applications in wave-control engineering. PMID:25403089

  2. Electromagnetically induced transparency of 87Rb in a buffer gas cell with magnetic field

    NASA Astrophysics Data System (ADS)

    Cheng, Hong; Wang, Han-Mu; Zhang, Shan-Shan; Xin, Pei-Pei; Luo, Jun; Liu, Hong-Ping

    2017-05-01

    We have studied the phenomenon of electromagnetically induced transparency (EIT) of 87Rb vapor at room temperature in a magnetic field with an arbitrary angle to the laser propagation direction. Rather than exposing atoms to a parallelled or transverse magnetic field as usual, in our work, we apply a magnetic field (up to 45 Gauss) with an arbitrary angle to the laser propagation direction and the spectra become much more complex. More EIT dips are observed due to the Zeeman splitting on the D 2 line of 87Rb in a {{Λ }}-type configuration. With a 5 Torr N2 buffer gas in the thermal 2 cm vapor cell, the state {5}2{P}3/2 has a very short effective lifetime, corresponding to a large energy broadening, which removes the velocity selective optical pumping effect almost completely and keeps the high resolution EIT spectrum for the energy splitting of 87Rb in magnetic fields. The shifting of the EIT resonances with the strength of the applied magnetic field coincides well with the theory based on a full matrix Hamiltonian combined with a spectral decomposition method. Our work can be extended to measure the magnetic field vector in space. The effects of the detuning of the probe and coupling beams on the spectral lines are also investigated.

  3. Intracavity Rydberg-atom electromagnetically induced transparency using a high-finesse optical cavity

    NASA Astrophysics Data System (ADS)

    Sheng, Jiteng; Chao, Yuanxi; Kumar, Santosh; Fan, Haoquan; Sedlacek, Jonathon; Shaffer, James P.

    2017-09-01

    We present an experimental study of cavity-assisted Rydberg-atom electromagnetically induced transparency (EIT) using a high-finesse optical cavity (F ˜28 000 ). Rydberg atoms are excited via a two-photon transition in a ladder-type EIT configuration. A three-peak structure of the cavity transmission spectrum is observed when Rydberg EIT is generated inside the cavity. The two symmetrically spaced side peaks are caused by bright-state polaritons, while the central peak corresponds to a dark-state polariton. Anticrossing phenomena and the effects of mirror adsorbate electric fields are studied under different experimental conditions. We determine a lower bound on the coherence time for the system of 7.26 ±0.06 μ s , most likely limited by laser dephasing. The cavity-Rydberg EIT system can be useful for single-photon generation using the Rydberg blockade effect, studying many-body physics, and generating novel quantum states among many other applications.

  4. Dressed-state electromagnetically induced transparency for light storage in uniform-phase spin waves

    NASA Astrophysics Data System (ADS)

    Šibalić, N.; Kondo, J. M.; Adams, C. S.; Weatherill, K. J.

    2016-09-01

    We present, experimentally and theoretically, a scheme for dressed-state electromagnetically induced transparency (EIT) in a three-step cascade system in which a four-level system is mapped into an effective three-level system. Theoretical analysis reveals that the scheme provides coherent-state control via adiabatic following and a generalized protocol for light storage in uniform phase spin-waves that are insensitive to motional dephasing. The three-step driving enables a number of other features, including spatial selectivity of the excitation region within the atomic medium, and kick-free and Doppler-free excitation that produces narrow resonances in thermal vapor. As a proof of concept, we present an experimental demonstration of the generalized EIT scheme using the 6 S1 /2→6 P3 /2→7 S1 /2→8 P1 /2 excitation path in thermal cesium vapor. This technique could be applied to cold and thermal ensembles to enable longer storage times for Rydberg polaritons.

  5. Polarization independent and tunable plasmonic structure for mimicking electromagnetically induced transparency in the reflectance spectrum

    NASA Astrophysics Data System (ADS)

    Guo, B. S.; Loo, Y. L.; Ong, C. K.

    2017-10-01

    This paper proposes a plasmonic metamaterial that is able to mimic electromagnetically induced transparency in the reflectance spectrum within the GHz frequency range. Each meta-atom consists of a cross-slot structure as the bright resonator positioned on one side of the FR-4 substrate, and four spiral structures as the dark resonator located on the opposite side. Free space experimental results demonstrate that at normal incidence of plane wave, the metamaterial possesses the properties of tunability and polarization independence. In addition, based on simulation results the metamaterial also possesses slow wave property, with group refractive index of 56; and refractive-index-based sensing capability, with figure of merit of 6.1. In the strong coupling configuration, the plasma frequency and coupling constant of the metamaterial were calculated to be approximately 5.4 × 1010 rad s-1 and 9.8 × 109 rad s-1 respectively. While the respective damping constants of the bright resonator and dark resonator were calculated to be approximately 4.6 × 1010 rad s-1 and 1.9 × 1010 rad s-1.

  6. Plasmonic-induced transparency in a MIM waveguide with two side-coupled cavities

    NASA Astrophysics Data System (ADS)

    Noual, Adnane; Abouti, Ossama El; El Boudouti, El Houssaine; Akjouj, Abdellatif; Pennec, Yan; Djafari-Rouhani, Bahram

    2017-01-01

    We investigate numerically the classical analogue of electromagnetically induced transparency (EIT) in a nanoplasmonic structure constituted by two side-coupled cavities. Two configurations are considered: (1) two cavities connected symmetrically on each side of the waveguide; (2) two cavities situated on the same side. In the first case, the EIT resonance occurs as a consequence of the destructive interference between the two cavities (playing the role of two coupled radiative oscillators), whereas in the second situation, the phenomenon arises due to a coupling between dark and radiative resonators. By detuning the sizes of the two cavities (i.e., the length difference Δ L, keeping their width w similar), we show that the position, width and quality factor of the EIT resonance depend strongly on Δ L. The effect of the metal gap separating the two cavities from the waveguide is also discussed. These results may have important applications for designing integrated devices such as narrow-frequency optical filters, novel sensors and high-speed switches.

  7. Plasmonic metamaterial for electromagnetically induced transparency analogue and ultra-high figure of merit sensor

    PubMed Central

    Wu, Dong; Liu, Yumin; Yu, Li; Yu, Zhongyuan; Chen, Lei; Li, Ruifang; Ma, Rui; Liu, Chang; Zhang, Jinqiannan; Ye, Han

    2017-01-01

    In this work, using finite-difference time-domain method, we propose and numerically demonstrate a novel way to achieve electromagnetically induced transparency (EIT) phenomenon in the reflection spectrum by stacking two different types of coupling effect among different elements of the designed metamaterial. Compared with the conventional EIT-like analogues coming from only one type of coupling effect between bright and dark meta-atoms on the same plane, to our knowledge the novel approach is the first to realize the optically active and precise control of the wavelength position of EIT-like phenomenon using optical metamaterials. An on-to-off dynamic control of the EIT-like phenomenon also can be achieved by changing the refractive index of the dielectric substrate via adjusting an optical pump pulse. Furthermore, in near infrared region, the metamaterial structure can be operated as an ultra-high resolution refractive index sensor with an ultra-high figure of merit (FOM) reaching 3200, which remarkably improve the FOM value of plasmonic refractive index sensors. The novel approach realizing EIT-like spectral shape with easy adjustment to the working wavelengths will open up new avenues for future research and practical application of active plasmonic switch, ultra-high resolution sensors and active slow-light devices. PMID:28332629

  8. Linear and nonlinear light propagations in a Doppler-broadened medium via electromagnetically induced transparency

    NASA Astrophysics Data System (ADS)

    Li, Liang; Huang, Guoxiang

    2010-08-01

    We present a systematic theoretical study to deal with linear and nonlinear light propagations in a Doppler-broadened three-level Λ system via electromagnetically induced transparency (EIT), with incoherent population exchange between two lower energy levels taken into account. Through a careful analysis of base state and linear excitation, we show that the EIT condition of the system is given by |Ωc|2γ31≫2γ21ΔωD2, where Ωc is half the Rabi frequency of the control field, ΔωD is the Doppler width, and γjl is the decay rate of the coherence between states |j> and |l>. Under this condition, the effect of incoherent population exchange is insignificant, while dephasing dominates the decoherence of the system. This condition also ensures the validity of the weak nonlinear perturbation theory used in this work for solving the Maxwell-Bloch equations with inhomogeneous broadening. We then investigate the nonlinear propagation of the probe field and show that it is possible to form temporal optical solitons in the Doppler-broadened medium. Such solitons have ultraslow propagating velocity and can be generated in very low light power. The possibility of realizing (1+1)-dimensional and (2+1)-dimensional spatial optical solitons in the adiabatic regime of the system is also discussed.

  9. Linear and nonlinear light propagations in a Doppler-broadened medium via electromagnetically induced transparency

    SciTech Connect

    Li Liang; Huang Guoxiang

    2010-08-15

    We present a systematic theoretical study to deal with linear and nonlinear light propagations in a Doppler-broadened three-level {Lambda} system via electromagnetically induced transparency (EIT), with incoherent population exchange between two lower energy levels taken into account. Through a careful analysis of base state and linear excitation, we show that the EIT condition of the system is given by |{Omega}{sub c}|{sup 2{gamma}}{sub 31}>>2{gamma}{sub 21{Delta}{omega}D}{sup 2}, where {Omega}{sub c} is half the Rabi frequency of the control field, {Delta}{omega}{sub D} is the Doppler width, and {gamma}{sub jl} is the decay rate of the coherence between states |j> and |l>. Under this condition, the effect of incoherent population exchange is insignificant, while dephasing dominates the decoherence of the system. This condition also ensures the validity of the weak nonlinear perturbation theory used in this work for solving the Maxwell-Bloch equations with inhomogeneous broadening. We then investigate the nonlinear propagation of the probe field and show that it is possible to form temporal optical solitons in the Doppler-broadened medium. Such solitons have ultraslow propagating velocity and can be generated in very low light power. The possibility of realizing (1+1)-dimensional and (2+1)-dimensional spatial optical solitons in the adiabatic regime of the system is also discussed.

  10. Plasmonic metamaterial for electromagnetically induced transparency analogue and ultra-high figure of merit sensor.

    PubMed

    Wu, Dong; Liu, Yumin; Yu, Li; Yu, Zhongyuan; Chen, Lei; Li, Ruifang; Ma, Rui; Liu, Chang; Zhang, Jinqiannan; Ye, Han

    2017-03-23

    In this work, using finite-difference time-domain method, we propose and numerically demonstrate a novel way to achieve electromagnetically induced transparency (EIT) phenomenon in the reflection spectrum by stacking two different types of coupling effect among different elements of the designed metamaterial. Compared with the conventional EIT-like analogues coming from only one type of coupling effect between bright and dark meta-atoms on the same plane, to our knowledge the novel approach is the first to realize the optically active and precise control of the wavelength position of EIT-like phenomenon using optical metamaterials. An on-to-off dynamic control of the EIT-like phenomenon also can be achieved by changing the refractive index of the dielectric substrate via adjusting an optical pump pulse. Furthermore, in near infrared region, the metamaterial structure can be operated as an ultra-high resolution refractive index sensor with an ultra-high figure of merit (FOM) reaching 3200, which remarkably improve the FOM value of plasmonic refractive index sensors. The novel approach realizing EIT-like spectral shape with easy adjustment to the working wavelengths will open up new avenues for future research and practical application of active plasmonic switch, ultra-high resolution sensors and active slow-light devices.

  11. Light storage based on four-wave mixing and electromagnetically induced transparency in cold atoms

    NASA Astrophysics Data System (ADS)

    Wu, Jinghui; Liu, Yang; Ding, Dong-Sheng; Zhou, Zhi-Yuan; Shi, Bao-Sen; Guo, Guang-Can

    2013-01-01

    We performed an experiment to observe the storage of an input probe field and an idler field generated through an off-axis four-wave mixing (FWM) process via a double-Λ configuration in a cold atomic ensemble. We analyzed the underlying physics in detail and found that the retrieved idler field came from two parts if there was no single-photon detuning for the pump pulse: Part 1 was from the collective atomic spin (the input probe field, the coupling field, and the pump field combined to generate the idler field through FWM; then the idler was stored through electromagnetically induced transparency). Part 2 was from the generated new FWM process during the retrieval process (the retrieved probe field, the coupling field, and the pump field combined to generate a new FWM signal). If there was single-photon detuning for the pump pulse, then the retrieved idler was mainly from part 2. The retrieved two fields exhibited damped oscillations with the same oscillatory period when a homogeneous external magnetic field was applied, which was caused by the Larmor spin precession. We also experimentally realized the storage and retrieval of an image of light using FWM, in which an image was added into the input signal. After the storage, the retrieved idler beams and input signal carried the same image. This image storage technique holds promise for applications in image processing, remote sensing, and quantum communication.

  12. Controlled Electromagnetically Induced Transparency and Fano Resonances in Hybrid BEC-Optomechanics

    NASA Astrophysics Data System (ADS)

    Yasir, Kashif Ammar; Liu, Wu-Ming

    2016-03-01

    Cavity-optomechanics, a tool to manipulate mechanical effects of light to couple optical field with other physical objects, is the subject of increasing investigations, especially with regards to electromagnetically induced transparency (EIT). EIT, a result of Fano interference among different atomic transition levels, has acquired a significant importance in many areas of physics, such as atomic physics and quantum optics. However, controllability of such multi-dimensional systems has remained a crucial issue. In this report, we investigate the controllability of EIT and Fano resonances in hybrid optomechanical system composed of cigar-shaped Bose-Einstein condensate (BEC), trapped inside high-finesse Fabry-Pérot cavity with one vibrational mirror, driven by a single mode optical field and a transverse pump field. The transverse field is used to control the phenomenon of EIT. It is detected that the strength of transverse field is not only efficiently amplifying or attenuating out-going optical mode but also providing an opportunity to enhance the strength of Fano-interactions which leads to the amplification of EIT-window. To observe these phenomena in laboratory, we suggest a certain set of experimental parameters. The results provide a route for tunable manipulation of optical phenomena, like EIT, which could be a significant step in quantum engineering.

  13. Density matrix reconstruction of three-level atoms via Rydberg electromagnetically induced transparency

    NASA Astrophysics Data System (ADS)

    Gavryusev, V.; Signoles, A.; Ferreira-Cao, M.; Zürn, G.; Hofmann, C. S.; Günter, G.; Schempp, H.; Robert-de-Saint-Vincent, M.; Whitlock, S.; Weidemüller, M.

    2016-08-01

    We present combined measurements of the spatially resolved optical spectrum and the total excited-atom number in an ultracold gas of three-level atoms under electromagnetically induced transparency conditions involving high-lying Rydberg states. The observed optical transmission of a weak probe laser at the center of the coupling region exhibits a double peaked spectrum as a function of detuning, while the Rydberg atom number shows a comparatively narrow single resonance. By imaging the transmitted light onto a charge-coupled-device camera, we record hundreds of spectra in parallel, which are used to map out the spatial profile of Rabi frequencies of the coupling laser. Using all the information available we can reconstruct the full one-body density matrix of the three-level system, which provides the optical susceptibility and the Rydberg density as a function of spatial position. These results help elucidate the connection between three-level interference phenomena, including the interplay of matter and light degrees of freedom and will facilitate new studies of many-body effects in optically driven Rydberg gases.

  14. Pump-tuned plasmon-induced transparency for sensing and switching applications

    NASA Astrophysics Data System (ADS)

    Shahamat, Yadollah; Vahedi, Mohammad

    2017-10-01

    A novel implementation for plasmon-induced transparency (PIT) is investigated theoretically and numerically. The structure is composed of a bus waveguide coupled to a nanodisk and two internally tangent disks (TITD). It is shown that the PIT peak can be tuned from 782 to 815 nm using an external pump laser with an intensity of up to 24.39 MW/cm2 (power ≅ 2 mW). The wavelength, transmission and width of the PIT peak can be adjusted by changing the nanodisk-TITD gap and the radius of the internal disk. The proposed structure can be well employed as a nanosensor, with a refractive index sensitivity and figure of merit equal to 690 nm RIU-1 and 49.28 RIU-1 respectively. In addition, the operation of a plasmonic switch based on the proposed structure is investigated. The switch demonstrates a good modulation depth (up to 20 dB), increasing almost monotonically with an increase of the pump intensity in the range of 0-28 MW/cm2.

  15. Rogue waves and W-shaped solitons in the multiple self-induced transparency system

    NASA Astrophysics Data System (ADS)

    Wang, Xin; Liu, Chong; Wang, Lei

    2017-09-01

    We study localized nonlinear waves on a plane wave background in the multiple self-induced transparency (SIT) system, which describes an important enhancement of the amplification and control of optical waves compared to the single SIT system. A hierarchy of exact multiparametric rational solutions in a compact determinant representation is presented. We demonstrate that this family of solutions contain known rogue wave solutions and unusual W-shaped soliton solutions. State transitions between the fundamental rogue waves and W-shaped solitons as well as higher-order nonlinear superposition modes are revealed in the zero-frequency perturbation region by the suitable choice for the background wavenumber of the electric field component. Particularly, it is found that the multiple SIT system can admit both stationary and nonstationary W-shaped solitons in contrast to the stationary results in the single SIT system. Moreover, the W-shaped soliton complex which is formed by a certain number of fundamental W-shaped solitons with zero phase parameters and its decomposition mechanism in the case of the nonzero phase parameters are shown. Meanwhile, some important characteristics of the nonlinear waves including trajectories and spectrum are discussed through the numerical and analytical methods.

  16. Optomechanically induced transparency in the presence of an external time-harmonic-driving force

    PubMed Central

    Ma, Jinyong; You, Cai; Si, Liu-Gang; Xiong, Hao; Li, Jiahua; Yang, Xiaoxue; Wu, Ying

    2015-01-01

    We propose a potentially valuable scheme to measure the properties of an external time-harmonic-driving force with frequency ω via investigating its interaction with the combination of a pump field and a probe field in a generic optomechanical system. We show that the spectra of both the cavity field and output field in the configuration of optomechanically induced transparency are greatly modified by such an external force, leading to many interesting linear and non-linear effects, such as the asymmetric structure of absorption in the frequency domain and the antisymmetry breaking of dispersion near ω = ωm. Furthermore, we find that our scheme can be used to measure the initial phase of the external force. More importantly, this setup may eliminate the negative impact of thermal noise on the measurement of the weak external force in virtue of the process of interference between the probe field and the external force. Finally, we show that our configuration can be employed to improve the measurement resolution of the radiation force produced by a weak ultrasonic wave. PMID:26062029

  17. Multispectral plasmon-induced transparency in hyperfine terahertz meta-molecules

    NASA Astrophysics Data System (ADS)

    Yang, Shengyan; Xia, Xiaoxiang; Liu, Zhe; Yiwen, E.; Wang, Yujin; Tang, Chengchun; Li, Wuxia; Li, Junjie; Wang, Li; Gu, Changzhi

    2016-11-01

    We experimentally and theoretically demonstrated an approach to achieve multispectral plasmon-induced transparency (PIT) by utilizing meta-molecules that consist of hyperfine terahertz meta-atoms. The feature size of such hyperfine meta-atoms is 400 nm, which is one order smaller than that of normal terahertz metamaterials. The hyperfine meta-atoms with close eigenfrequencies and narrow resonant responses introduce different metastable energy levels, which makes the multispectral PIT possible. In the triple PIT system, the slow light effect is further confirmed as the effective group delay at three transmission windows can reach 7.3 ps, 7.4 ps and 4.5 ps, respectively. Precisely controllable manipulation of the PIT peaks in such hyperfine meta-molecules was also proven. The new hyperfine planar design is not only suitable for high-integration applications, but also exhibits significant slow light effect, which has great potential in advanced multichannel optical information processing. Moreover, it reveals the possibility to construct hyperfine N-level energy systems by artificial hyperfine plasmonic structures, which brings a significant prospect for applications on miniaturized plasmonic devices.

  18. Local and nonlocal optically induced transparency effects in graphene-silicon hybrid nanophotonic integrated circuits.

    PubMed

    Yu, Longhai; Zheng, Jiajiu; Xu, Yang; Dai, Daoxin; He, Sailing

    2014-11-25

    Graphene is well-known as a two-dimensional sheet of carbon atoms arrayed in a honeycomb structure. It has some unique and fascinating properties, which are useful for realizing many optoelectronic devices and applications, including transistors, photodetectors, solar cells, and modulators. To enhance light-graphene interactions and take advantage of its properties, a promising approach is to combine a graphene sheet with optical waveguides, such as silicon nanophotonic wires considered in this paper. Here we report local and nonlocal optically induced transparency (OIT) effects in graphene-silicon hybrid nanophotonic integrated circuits. A low-power, continuous-wave laser is used as the pump light, and the power required for producing the OIT effect is as low as ∼0.1 mW. The corresponding power density is several orders lower than that needed for the previously reported saturated absorption effect in graphene, which implies a mechanism involving light absorption by the silicon and photocarrier transport through the silicon-graphene junction. The present OIT effect enables low power, all-optical, broadband control and sensing, modulation and switching locally and nonlocally.

  19. Electromagnetically induced transparency in a Y system with single Rydberg state

    NASA Astrophysics Data System (ADS)

    Tian, Xue-Dong; Liu, Yi-Mou; Yan, Xiao-Bo; Cui, Cui-Li; Zhang, Yan

    2015-06-01

    We study the transmitted intensity and correlation properties of a probe field propagating through a sample of cold interacting 87Rb atoms driven into the Y level configuration with single Rydberg state. We find two electromagnetically induced transparency (EIT) windows in the transmission spectrum. One window is linear since it is immune to the incident probe field. The other window depth is sensitive to the incident probe intensity, exhibiting cooperative nonlinearity. Meanwhile, the linear window is low but the transmissivity at the nonlinear window can reach nearly 100% in case of the weak probe intensity. When two EIT windows overlap, the cooperative optical nonlinearity plays a leading role in the degenerate window. In addition, the probe propagation is affected by its two-photon correlation which is suppressed at the center of nonlinear window and is enhanced near the boundaries of two windows. The two-photon correlation is also sensitive to the probe field, and that means we can attain the strongest photon bunching (anti-bunching) effect by controlling the probe and coupling fields.

  20. Engineered absorption enhancement and induced transparency in coupled molecular and plasmonic resonator systems.

    PubMed

    Adato, Ronen; Artar, Alp; Erramilli, Shyamsunder; Altug, Hatice

    2013-06-12

    Coupled plasmonic resonators have become the subject of significant research interest in recent years as they provide a route to dramatically enhanced light-matter interactions. Often, the design of these coupled mode systems draws intuition and inspiration from analogies to atomic and molecular physics systems. In particular, they have been shown to mimic quantum interference effects, such as electromagnetically induced transparency (EIT) and Fano resonances. This analogy also been used to describe the surface-enhanced absorption effect where a plasmonic resonance is coupled to a weak molecular resonance. These important phenomena are typically described using simple driven harmonic (or linear) oscillators (i.e., mass-on-a-spring) coupled to each other. In this work, we demonstrate the importance of an essential interdependence between the rate at which the system can be driven by an external field and its damping rate through radiative loss. This link is required in systems exhibiting time-reversal symmetry and energy conservation. Not only does it ensure an accurate and physically consistent description of resonant systems but leads directly to interesting new effects. Significantly, we demonstrate this dependence to predict a transition between EIT and electromagnetically induced absorption that is solely a function of the ratio of the radiative to intrinsic loss rates in coupled resonator systems. Leveraging the temporal coupled mode theory, we introduce a unique and intuitive picture that accurately describes these effects in coupled plasmonic/molecular and fully plasmonic systems. We demonstrate our approach's key features and advantages analytically as well as experimentally through surface-enhanced absorption spectroscopy and plasmonic metamaterial applications.

  1. Nonlinear optical effects manifested by electromagnetic induced transparency in cold atoms

    NASA Astrophysics Data System (ADS)

    Zhang, Jiepeng

    2008-10-01

    This dissertation reports experimental studies of nonlinear optical effects manifested by electromagnetically induced transparency (EIT) in cold Rb atoms. The cold Rb atoms are confined in a magneto-optic trap (MOT) obtained with the standard laser cooling and trapping technique. Because of the near zero Doppler shift and a high phase density, the cold Rb sample is well suited for studies of atomic coherence and interference and related applications, and the experiments can be compared quantitatively with theoretical calculations. It is shown that with EIT induced in the multi-level Rb system by laser fields, the linear absorption is suppressed and the nonlinear susceptibility is enhanced, which enables studies of nonlinear optics in the cold atoms with slow photons and at low light intensities. Three independent experiments are described and the experimental results are presented. First, an experimental method that can produce simultaneously co-propagating slow and fast light pulses is discussed and the experimental demonstration is reported. Second, it is shown that in a three-level Rb system coupled by multi-color laser fields, the multi-channel two-photon Raman transitions can be manipulated by the relative phase and frequency of a control laser field. Third, a scheme for all-optical switching near single photon levels is developed. The scheme is based on the phase-dependent multi-photon interference in a coherently coupled four-level system. The phase dependent multi-photon interference is observed and switching of a single light pulse by a control pulse containing ˜20 photons is demonstrated. These experimental studies reveal new phenomena manifested by quantum coherence and interference in cold atoms, contribute to the advancement of fundamental quantum optics and nonlinear optics at ultra-low light intensities, and may lead to the development of new techniques to control quantum states of atoms and photons, which will be useful for applications in quantum

  2. Dipole nanolaser

    NASA Astrophysics Data System (ADS)

    Protsenko, I. E.; Uskov, A. V.; Zaimidoroga, O. A.; Samoilov, V. N.; O'Reilly, E. P.

    2005-06-01

    A “dipole” laser is proposed consisting of a nanoparticle and a two-level system with population inversion. If the threshold conditions are fulfilled, the dipole interaction between the two-level system and the nanoparticle leads to coherent oscillations in the polarization of the particles, even in the absence of an external electromagnetic field. The emitted radiation has a dipolar distribution. It does not need an optical cavity, and has a very small volume, ˜0.1μm3 , which can be important for applications in microelectronics. Estimates of the threshold conditions are carried out for a dipole laser composed of a quantum dot and a silver nanoparticle.

  3. The Effect of the Incident Relative Phase on the Four-Wave Mixing Field and the Electromagnetically Induced Transparency

    SciTech Connect

    Niu, Y.; Gong, S.

    2005-10-15

    In a {lambda}-type system employing a two-photon pump field, a four-wave mixing field can be generated simultaneously and, hence, a closed-loop system forms. We study theoretically the effect of the relative phase between the two incident fields on the generated four-wave mixing field and the electromagnetically induced transparency. It is found that the phase of the generated four-wave mixing field is the sum of the incident relative phase and a fixed phase that is irrelative to the incident relative phase. Hence, the total phase of the closed-loop system is independent of the incident relative phase. As a result, the incident relative phase has no effect on the electromagnetically induced transparency, which is different from the case of a {lambda}-type loop system closed by a third incident field.

  4. Attenuated total reflection response to wavelength tuning of plasmon-induced transparency in a metal-insulator-metal structure.

    PubMed

    Matsunaga, Kouki; Watanabe, Takeshi; Neo, Yoichiro; Matsumoto, Takahiro; Tomita, Makoto

    2016-11-15

    We experimentally demonstrated a plasmon-induced transparency in a metal-insulator-metal (MIM) structure based on the attenuated total reflection (ATR) response. Here, the MIM waveguide (MIMWG) mode and the surface plasmon polariton (SPP) resonance mode acted as low- and high-Q resonance modes, respectively. The dependence of the resonance angles of SPP and MIMWG mode resonances on the incident wavelength differed, which allowed the coupling condition between the two modes to be tuned via the wavelength. When the resonance angles of the two modes coincided, the ATR response showed a symmetric plasmon-induced transparency spectrum; in contrast, when the resonance angles were detuned, the ATR exhibited a sharp asymmetric spectrum characteristic to off-resonance Fano interference.

  5. Overlapping resonances interference-induced transparency: the S0 → S2/S1 photoexcitation spectrum of pyrazine.

    PubMed

    Grinev, Timur; Shapiro, Moshe; Brumer, Paul

    2012-09-07

    The phenomenon of "overlapping resonances interference-induced transparency" (ORIT) is introduced and studied in detail for the S(0) → S(2)/S(1) photoexcitation of cold pyrazine (C(4)H(4)N(2)). In ORIT, a molecule becomes transparent at specific wavelengths due to interferences between envelopes of spectral lines displaying overlapping resonances. An example is the S(2) ↔ S(1) internal conversion in pyrazine where destructive interference between overlapping resonances causes the S(0) → S(2)/S(1) light absorption to disappear at certain wavelengths. ORIT may be of practical importance in multi-component mixtures where it would allow for the selective excitation of some molecules in preference to others. Interference-induced cross section enhancement is also shown.

  6. Self-Induced Transparency and Electromagnetic Pulse Compression in a Plasma or an Electron Beam under Cyclotron Resonance Conditions

    SciTech Connect

    Ginzburg, N. S.; Zotova, I. V.; Sergeev, A. S.

    2010-12-30

    Based on analogy to the well-known process of the self-induced transparency of an optical pulse propagating through a passive two-level medium we describe similar effects for a microwave pulse interacting with a cold plasma or rectilinear electron beam under cyclotron resonance condition. It is shown that with increasing amplitude and duration of an incident pulse the linear cyclotron absorption is replaced by the self-induced transparency when the pulse propagates without damping. In fact, the initial pulse decomposes to one or several solitons with amplitude and duration defined by its velocity. In a certain parameter range, the single soliton formation is accompanied by significant compression of the initial electromagnetic pulse. We suggest using the effect of self-compression for producing multigigawatt picosecond microwave pulses.

  7. The difference in noise property between the Autler—Townes splitting medium and the electromagnetically induced transparent medium

    NASA Astrophysics Data System (ADS)

    Li, Zhong-Hua; Li, Yuan; Dou, Ya-Fang; Zhang, Jun-Xiang

    2012-03-01

    The quantum noise of squeezed probe light passing through an atomic system with different electromagnetically induced transparency and Autler—Townes splitting effects is investigated theoretically. It is found that the optimal squeezing preservation of the outgoing probe beam occurs in the strong-coupling-field regime rather than in the weak-coupling-field regime. In the weak-coupling-field regime, which was recently recognized as the electromagnetically induced transparency regime (Abi-Salloum T Y 2010 Phys. Rev. A 81 053836), the output amplitude noise is affected mainly by the atomic noise originating from the random decay process of atoms. While in the strong-coupling-field regime, defined as the Autler—Townes splitting regime, the output amplitude noise is affected mainly by the phase-to-amplitude conversion noise. This is useful in improving the quality of the experiment for efficient quantum memory, and hence has an application in quantum information processing.

  8. Opening four-wave mixing and six-wave mixing channels via dual electromagnetically induced transparency windows.

    PubMed

    Zhang, Yanpeng; Brown, Andy W; Xiao, Min

    2007-09-21

    Highly efficient four-wave mixing (FWM) and six-wave mixing (SWM) processes can coexist in a four-level Y-type atomic system due to atomic coherence. The simultaneously opened dual electromagnetically induced transparency windows in this four-level atomic system allow observation of these two nonlinear optical processes at the same time, which enables detailed studies of the interplay between the FWM and SWM processes. Three-photon and five-photon destructive interferences are also observed.

  9. Ultralow-power and ultrafast all-optical tunable plasmon-induced transparency in metamaterials at optical communication range

    NASA Astrophysics Data System (ADS)

    Zhu, Yu; Hu, Xiaoyong; Fu, Yulan; Yang, Hong; Gong, Qihuang

    2013-08-01

    Actively all-optical tunable plasmon-induced transparency in metamaterials paves the way for achieving ultrahigh-speed quantum information processing chips. Unfortunately, up to now, very small experimental progress has been made for all-optical tunable plasmon-induced transparency in metamaterials in the visible and near-infrared range because of small third-order optical nonlinearity of conventional materials. The achieved operating pump intensity was as high as several GW/cm2 order. Here, we report an ultralow-power and ultrafast all-optical tunable plasmon-induced transparency in metamaterials coated on polycrystalline indium-tin oxide layer at the optical communication range. Compared with previous reports, the threshold pump intensity is reduced by four orders of magnitude, while an ultrafast response time of picoseconds order is maintained. This work not only offers a way to constructing photonic materials with large nonlinearity and ultrafast response, but also opens up the possibility for realizing quantum solid chips and ultrafast integrated photonic devices based on metamaterials.

  10. Ultralow-power and ultrafast all-optical tunable plasmon-induced transparency in metamaterials at optical communication range.

    PubMed

    Zhu, Yu; Hu, Xiaoyong; Fu, Yulan; Yang, Hong; Gong, Qihuang

    2013-01-01

    Actively all-optical tunable plasmon-induced transparency in metamaterials paves the way for achieving ultrahigh-speed quantum information processing chips. Unfortunately, up to now, very small experimental progress has been made for all-optical tunable plasmon-induced transparency in metamaterials in the visible and near-infrared range because of small third-order optical nonlinearity of conventional materials. The achieved operating pump intensity was as high as several GW/cm(2) order. Here, we report an ultralow-power and ultrafast all-optical tunable plasmon-induced transparency in metamaterials coated on polycrystalline indium-tin oxide layer at the optical communication range. Compared with previous reports, the threshold pump intensity is reduced by four orders of magnitude, while an ultrafast response time of picoseconds order is maintained. This work not only offers a way to constructing photonic materials with large nonlinearity and ultrafast response, but also opens up the possibility for realizing quantum solid chips and ultrafast integrated photonic devices based on metamaterials.

  11. Ultralow-power and ultrafast all-optical tunable plasmon-induced transparency in metamaterials at optical communication range

    PubMed Central

    Zhu, Yu; Hu, Xiaoyong; Fu, Yulan; Yang, Hong; Gong, Qihuang

    2013-01-01

    Actively all-optical tunable plasmon-induced transparency in metamaterials paves the way for achieving ultrahigh-speed quantum information processing chips. Unfortunately, up to now, very small experimental progress has been made for all-optical tunable plasmon-induced transparency in metamaterials in the visible and near-infrared range because of small third-order optical nonlinearity of conventional materials. The achieved operating pump intensity was as high as several GW/cm2 order. Here, we report an ultralow-power and ultrafast all-optical tunable plasmon-induced transparency in metamaterials coated on polycrystalline indium-tin oxide layer at the optical communication range. Compared with previous reports, the threshold pump intensity is reduced by four orders of magnitude, while an ultrafast response time of picoseconds order is maintained. This work not only offers a way to constructing photonic materials with large nonlinearity and ultrafast response, but also opens up the possibility for realizing quantum solid chips and ultrafast integrated photonic devices based on metamaterials. PMID:23903825

  12. Single and multi-band electromagnetic induced transparency-like metamaterials with coupled split ring resonators

    NASA Astrophysics Data System (ADS)

    Bagci, Fulya; Akaoglu, Baris

    2017-08-01

    We present a metamaterial configuration exhibiting single and multi-band electromagnetic induced transparency (EIT)-like properties. The unit cell of the single band EIT-like metamaterial consists of a multi-split ring resonator surrounded by a split ring resonator. The multi-split ring resonator acts as a quasi-dark or dark resonator, depending on the polarization of the incident wave, and the split ring resonator serves as the bright resonator. Combination of these two resonators results in a single band EIT-like transmission inside the stop band. EIT-like transmission phenomenon is also clearly observed in the measured transmission spectrum at almost the same frequencies for vertical and horizontal polarized waves, and the numerical results are verified for normal incidence. Moreover, multi-band transmission windows are created within a wide band by combining the two slightly different single band EIT-like metamaterial unit cells that exhibit two different coupling strengths inside a supercell configuration. Group indices as high as 123 for single band and 488 for tri-band transmission, accompanying with high transmission rates (over 80%), are achieved, rendering the metamaterial very suitable for multi-band slow light applications. It is shown that the group delay of the propagating wave can be increased and dynamically controlled by changing the polarization angle. Multi-band EIT-like transmission is also verified experimentally, and a good agreement with simulations is obtained. The proposed novel methodology for obtaining multi-band EIT, which takes advantage of a supercell configuration by hosting slightly different configured unit cells, can be utilized for easily formation and manipulation of multi-band transmission windows inside a stop band.

  13. Electric field metrology for SI traceability: Systematic measurement uncertainties in electromagnetically induced transparency in atomic vapor

    NASA Astrophysics Data System (ADS)

    Holloway, Christopher L.; Simons, Matt T.; Gordon, Joshua A.; Dienstfrey, Andrew; Anderson, David A.; Raithel, Georg

    2017-06-01

    We investigate the relationship between the Rabi frequency (ΩRF, related to the applied electric field) and Autler-Townes (AT) splitting, when performing atom-based radio-frequency (RF) electric (E) field strength measurements using Rydberg states and electromagnetically induced transparency (EIT) in an atomic vapor. The AT splitting satisfies, under certain conditions, a well-defined linear relationship with the applied RF field amplitude. The EIT/AT-based E-field measurement approach derived from these principles is currently being investigated by several groups around the world as a means to develop a new SI-traceable RF E-field measurement technique. We establish conditions under which the measured AT-splitting is an approximately linear function of the RF electric field. A quantitative description of systematic deviations from the linear relationship is key to exploiting EIT/AT-based atomic-vapor spectroscopy for SI-traceable field measurement. We show that the linear relationship is valid and can be used to determine the E-field strength, with minimal error, as long as the EIT linewidth is small compared to the AT-splitting. We also discuss interesting aspects of the thermal dependence (i.e., hot- versus cold-atom) of this EIT-AT technique. An analysis of the transition from cold- to hot-atom EIT in a Doppler-mismatched cascade system reveals a significant change of the dependence of the EIT linewidth on the optical Rabi frequencies and of the AT-splitting on ΩRF.

  14. Electromagnetically Induced Transparency Experiments for the Advanced Undergraduate Laboratory: Suppression of Polarization Impurity and Stray Magnetic Fields

    NASA Astrophysics Data System (ADS)

    Campbell, Kaleb; Jackson, Richard; van Vleet, Matthew; Kuhnash, Kodi; Worth, Bradley; Day, Amanda; Bali, Samir

    2014-05-01

    We investigate electromagnetically induced transparency (EIT) and electromagnetically induced absorption (EIA) in rubidium vapor using a single laser beam and a scanning magnetic field co-aligned with the laser propagation direction. We show that polarization impurity, stray magnetic fields and imperfect optical alignments cause broadening of the EIT/EIA signal and other spurious effects. We describe a systematic approach to minimizing these undesired effects, which produces EIT/EIA signals nearly two orders of magnitude narrower than the natural linewidth. We gratefully acknowledge funding from the American Chemical Society Petroleum Research Fund and Miami University. We also acknowledge the Miami University Instrumentation Laboratory for their invaluable contributions.

  15. Analog of midinfrared electromagnetically induced-transparency and slow rainbow trapping light based on graphene nanoribbon-coated silica substrate

    NASA Astrophysics Data System (ADS)

    Wei, Buzheng; Jian, Shuisheng

    2017-04-01

    A midinfrared band-tunable graphene-based plasmonic waveguide is analytically and numerically investigated to realize electromagnetically induced-transparency-like transmission and to slow rainbow trapping light. By applying different Fermi energy levels to the top and bottom graphene nanoribbons, a dynamic control of resonant wavelengths is thus obtained at the desired working regions. Plus, the structural size parameters play a significant role in modulating the resonant spectra and resonant depth. Combining the manipulation of the two sets of influential factors, the transparency window is therefore under control. Detailed investigations of the analytic mechanism of the device are made as well. Furthermore, the light signal that travels in the waveguide can be successfully slowed down to over 340 times the speed in a vacuum. If the nanoribbon width is gradiently distributed, the so-called rainbow trapping can be achieved. Hence, the device has potential applications in nanoimaging, sensing, integrated circuits, and light energy storage domains.

  16. Effect of buffer gas on an electromagnetically induced transparency in a ladder system using thermal rubidium vapor

    SciTech Connect

    Sargsyan, Armen; Sarkisyan, David; Krohn, Ulrich; Keaveney, James; Adams, Charles

    2010-10-15

    We report on the observation of electromagnetically induced transparency in a ladder system in the presence of a buffer gas. In particular, we study the 5S{sub 1/2}-5P{sub 3/2}-5D{sub 5/2} transition in thermal rubidium vapor with a neon buffer gas at a pressure of 6 Torr. In contrast to the line-narrowing effect of buffer gas on {Lambda} systems, we show that the presence of the buffer gas leads to an additional broadening of (34{+-}5) MHz, which suggests a cross section for Rb(5D{sub 5/2})-Ne of {sigma}{sub k}{sup (D)}=(23{+-}4)x10{sup -19} m{sup 2}. However, in the limit where the coupling Rabi frequency is larger than the collisional dephasing, a strong transparency feature can still be observed.

  17. Double plasmon induced transparency in disk and nanobars coupled nanosystems and its application to plasmonic resonance sensing

    NASA Astrophysics Data System (ADS)

    Chen, Fang; Yao, Duanzheng

    2016-05-01

    We demonstrate the realization of plasmon induced transparency (PIT) in a nanostructure composed of silver nanobars and a silver nanodisk. The optical properties of the planar metamaterials have been investigated theoretically in the paper. The classical coupled harmonic oscillator model demonstrates the PIT phenomenon in a nanodisk-nanobar system. Additionally, double PIT response is observed when two nanobars are located in proximity to the silver nanodisk. The PIT window wavelength and bandwidths can be efficiently tuned by controlling the geometric parameters such as the lengths of nanobars and the coupling distances between the nanodisk and nanobars. Moreover, the transparency window shows highly sensitive response to the refractive index of the environmental medium. A high figure of merit up to 15.5 of the asymmetrical system for refractive index sensing is achieved. The tunability of the PIT may have potential application on slow light and highly integrated optical circuits.

  18. Effect of hydrostatic pressure and magnetic field on electromagnetically induced transparency based nonlinear frequency conversion in quantum ring

    NASA Astrophysics Data System (ADS)

    Gumber, Sukirti; Gambhir, Monica; Jha, Pradip Kumar; Mohan, Man

    2016-10-01

    We study the combined effect of hydrostatic pressure and magnetic field on electromagnetically induced transparency in quantum ring. The high flexibility in size and shape of ring makes it possible to fabricate a nearly perfect two-dimensional quantum structure. We also explore the dependence of frequency conversion, measured in terms of third order nonlinear susceptibility χ(3) , on coupling field, hydrostatic pressure and magnetic field. Although, a dip in χ(3) is observed with the introduction of strong coupling field, it renders the ring structure transparent to generated wave thus effectively enhancing the output of nonlinear frequency conversion process. At a fixed coupling strength, the output can be further enhanced by increasing the magnetic field while it shows an inverse relationship with pressure. These parameters, being externally controlled, provide an easy handle to control the output of quantum ring which can be used as frequency converter in communication networks.

  19. Generic conditions for suppressing the coherent synchrotron radiation induced emittance growth in a two-dipole achromat

    NASA Astrophysics Data System (ADS)

    Jiao, Yi; Cui, Xiaohao; Huang, Xiyang; Xu, Gang

    2014-06-01

    The effect of the coherent synchrotron radiation (CSR) becomes evident, and leads to increased beam energy spread and transverse emittance dilution, as both the emittance and bunch length of the electron beams are continuously pushed down in present and forthcoming high-brightness light sources and linear colliders. Suppressing this effect is important to preserve the expected machine performance. Methods of the R-matrix analysis and the Courant-Snyder formalism analysis have been proposed to evaluate and to suppress the emittance growth due to CSR in achromatic cells. In this paper a few important modifications are made on these two methods, which enable us to prove that these two methods are equivalent to each other. With the modified analysis, we obtain explicit and generic conditions of cancelling the CSR-driven emittance excitation in a single achromat consisting of two dipoles of arbitrary bending angles. In spite of the fact that the analysis constrains itself in a linear regime, based on the assumption that CSR-induced particle energy deviation is proportional to both θ and ρ1/3, with θ being the bending angle and ρ the bending radius, it is demonstrated through ELEGANT simulations that the conditions derived from this analysis are still effective in suppressing the emittance growth when a more detailed one-dimensional CSR model is considered. In addition, it illustrates that the emittance growth can be reduced to a lower level with the proposed conditions than with the other two approaches, such as matching the beam envelope to the CSR kick and setting the cell-to-cell betatron phase advance to an appropriate value.

  20. Vertical transport in isotype InAlN/GaN dipole induced diodes grown by molecular beam epitaxy

    NASA Astrophysics Data System (ADS)

    Fireman, M. N.; Li, Haoran; Keller, Stacia; Mishra, Umesh K.; Speck, James S.

    2017-05-01

    InAlN dipole diodes were developed and fabricated on both (0001) Ga-Face and (" separators="| 000 1 ¯) N-face oriented GaN on sapphire templates by molecular beam epitaxy. The orientation and direction of the InAlN polarization dipole are functions of the substrate orientation and composition, respectively. Special consideration was taken to minimize growth differences and impurity uptake during growth on these orientations of opposite polarity. Comparison of devices on similarly grown structures with In compositions in excess of 50% reveals that dipole diodes shows poorer forward bias performance and exhibited an increase in reverse bias leakage, regardless of orientation. Similarly, (0001) Ga-face oriented InAlN at a lowered 40% In composition had poor device characteristics, namely, the absence of expected exponential turn on in forward bias. By contrast, at In compositions close to 40%, (" separators="| 000 1 ¯) N-face oriented InAlN devices had excellent performance, with over five orders of magnitude of rectification and extracted barrier heights of 0.53- 0.62 eV; these values are in close agreement with simulation. Extracted ideality factors ranging from 1.08 to 1.38 on these devices are further evidence of their optimal performance. Further discussion focuses on the growth and orientation conditions that may lead to this discrepancy yet emphasizes that with proper design and growth strategy, the rectifying dipole diodes can be achieved with InAlN nitride dipole layers.

  1. Probing temperature and damping rates in Bose-Einstein condensates through dephasing in electromagnetically induced transparency conditions

    SciTech Connect

    Roberts, D. C.

    2005-12-15

    We propose a method to probe Landau and Beliaev processes in dilute trapped atomic condensates with a multiple-state structure using electromagnetically induced transparency configurations. Under certain conditions, damping rates from these collisional processes are directly proportional to the dephasing rates, making it possible to determine damping rates through measurement of the dephasing. In the systems we consider, Landau decay rates are enhanced at low momenta, which allows one to distinguish between Landau-dominated and Beliaev-dominated regimes at the same temperature. Furthermore, the enhancement of Landau rates potentially provides a way to measure low temperatures (T<

  2. Colossal Kerr nonlinearity based on electromagnetically induced transparency in a five-level double-ladder atomic system.

    PubMed

    Hamedi, H R; Gharamaleki, Ali Hamrah; Sahrai, Mostafa

    2016-08-01

    The paper is aimed at modeling the enhanced Kerr nonlinearity in a five-level double-ladder-type atomic system based on electromagnetically induced transparency (EIT) by using the semi-classical density matrix method. We present an analytical model to explain the origin of Kerr nonlinearity enhancement. The scheme also results in a several orders of magnitude increase in the Kerr nonlinearity in comparison with the well-known four- and three-level atomic systems. In addition to the steady-state case, the time-dependent Kerr nonlinearity and the switching feature of EIT-based colossal Kerr nonlinearity is investigated for the proposed system.

  3. Multiple plasmon-induced transparency effects in a multimode-cavity-coupled metal-dielectric-metal waveguide

    NASA Astrophysics Data System (ADS)

    Chen, Zhiquan; Li, Hongjian; He, Zhihui; Xu, Hui; Zheng, Mingfei; Zhao, Mingzhuo

    2017-09-01

    We numerically and theoretically investigate multiple plasmon-induced transparency (PIT) effects in a multimode-cavity-coupled metal-dielectric-metal (MDM) waveguide system. The introduced multimode coupled-radiating oscillator theory (MC-ROT) gives a clear understanding of multiple PIT effects in the proposed system. Two and three PIT peaks appear in the transmission spectra corresponding to the symmetrical and asymmetrical structures, respectively. Evolution of the PIT peaks can be effectively tuned by adjusting the geometric dimensions and asymmetry of the structure. The ultra-compact plasmonic waveguide structure may have important applications for multichannel filters, optical switches, and other devices in integrated optical circuits.

  4. Tunable edge-mode-based mid-infrared plasmonically induced transparency in the coupling system of coplanar graphene ribbons

    NASA Astrophysics Data System (ADS)

    Li, Hong-Ju; Wang, Ling-Ling; Zhang, Bing-Hua; Zhai, Xiang

    2016-01-01

    The graphene ribbon waveguide with two short parallel, coupled coplanar strips is investigated. Because of the extreme destructive interference of the short strip resonators, an outstanding plasmonically induced transparency (PIT) window with a group time delay up to 0.28 ps is achieved in the mid-infrared region, with an excellent ultraslow-light feature. The PIT window is controlled by varying the coupling distance between resonators and is tuned dynamically by a small change in the chemical potential. Numerical results are confirmed using the coupled-mode theory (CMT). The planar structure will benefit the fabrication of plasmonic circuits for slow light and optical switching.

  5. Graphene based silicon-air grating structure to realize electromagnetically-induced-transparency and slow light effect

    NASA Astrophysics Data System (ADS)

    Wei, Buzheng; Liu, Huaiqing; Ren, Guobin; Yang, Yuguang; Ye, Shen; Pei, Li; Jian, Shuisheng

    2017-01-01

    A broad band tunable graphene based silicon-air grating structure is proposed. Electromagnetically-induced-transparency (EIT) window can be successfully tuned by virtually setting the desired Fermi energy levels on graphene sheets. Carrier mobility plays an important role in modulating the resonant depth. Furthermore, by changing the grating periods, light can be trapped at corresponding resonant positions where slow down factor is relatively larger than in the previous works. This structure can be used as a highly tunable optoelectronic device such as optical filter, broad-band modulator, plasmonic switches and buffers.

  6. Ab initio 3D potential energy and dipole moment surfaces for the CH4-Ar complex: Collision-induced intensity and dimer content

    NASA Astrophysics Data System (ADS)

    Kalugina, Yulia N.; Lokshtanov, Sergei E.; Cherepanov, Victor N.; Vigasin, Andrey A.

    2016-02-01

    We present new three-dimensional potential energy surface (PES) and dipole moment surfaces (DMSs) for the CH4-Ar van der Waals system. Ab initio calculations of the PES and DMS were carried out using the closed-shell single- and double-excitation coupled cluster approach with non-iterative perturbative treatment of triple excitations. The augmented correlation-consistent aug-cc-pVXZ (X = D,T,Q) basis sets were employed, and the energies obtained were then extrapolated to the complete basis set limit. The dipole moment surface was obtained using aug-cc-pVTZ basis set augmented with mid-bond functions for better description of exchange interactions. The second mixed virial coefficient was calculated and compared to available experimental data. The equilibrium constant for true dimer formation was calculated using classical partition function based on the knowledge of ab initio PES. Temperature variations of the zeroth spectral moment of the rototranslational collision-induced band as well as its true dimer constituent were traced with the use of the Boltzmann-weighted squared induced dipole properly integrated over respective phase space domains. Height profiles for N2-N2, N2-H2, CH4-N2, (CH4)2, and CH4-Ar true bound dimers in Titan's atmosphere were calculated with the use of reliable ab initio PESs.

  7. Ab initio 3D potential energy and dipole moment surfaces for the CH4-Ar complex: Collision-induced intensity and dimer content.

    PubMed

    Kalugina, Yulia N; Lokshtanov, Sergei E; Cherepanov, Victor N; Vigasin, Andrey A

    2016-02-07

    We present new three-dimensional potential energy surface (PES) and dipole moment surfaces (DMSs) for the CH4-Ar van der Waals system. Ab initio calculations of the PES and DMS were carried out using the closed-shell single- and double-excitation coupled cluster approach with non-iterative perturbative treatment of triple excitations. The augmented correlation-consistent aug-cc-pVXZ (X = D,T,Q) basis sets were employed, and the energies obtained were then extrapolated to the complete basis set limit. The dipole moment surface was obtained using aug-cc-pVTZ basis set augmented with mid-bond functions for better description of exchange interactions. The second mixed virial coefficient was calculated and compared to available experimental data. The equilibrium constant for true dimer formation was calculated using classical partition function based on the knowledge of ab initio PES. Temperature variations of the zeroth spectral moment of the rototranslational collision-induced band as well as its true dimer constituent were traced with the use of the Boltzmann-weighted squared induced dipole properly integrated over respective phase space domains. Height profiles for N2-N2, N2-H2, CH4-N2, (CH4)2, and CH4-Ar true bound dimers in Titan's atmosphere were calculated with the use of reliable ab initio  PESs.

  8. Self-induced transparency modelocking of quantum cascade lasers in the presence of saturable nonlinearity and group velocity dispersion.

    PubMed

    Talukder, Muhammad Anisuzzaman; Menyuk, Curtis R

    2010-03-15

    We consider the impact of saturable nonlinearity and group velocity dispersion on self-induced transparency (SIT) modelocking of quantum cascade lasers (QCLs). We find that self-induced transparency modelocking in QCLs can be obtained in the presence of saturable nonlinearity if the saturable loss or gain is below a critical limit. The limit for the saturable loss is significantly more stringent than the limit for the saturable gain. Stable modelocked pulses are also obtained in the presence of both normal and anomalous group velocity dispersion when its magnitude is below a critical value. The stability limit for the saturable loss becomes less stringent when group velocity dispersion is simultaneously present. However, the stability limit for the saturable gain is not significantly affected. All these limits depend on the ratio of the SIT-induced gain and absorpt n to the linear loss. Realistic values for both the saturable nonlinearity and chromatic dispersion are within the range in which SIT modelocking is predicted to be stable.

  9. Quantitative estimate of fs-laser induced refractive index changes in the bulk of various transparent materials

    NASA Astrophysics Data System (ADS)

    Mermillod-Blondin, A.; Seuthe, T.; Eberstein, M.; Grehn, M.; Bonse, J.; Rosenfeld, A.

    2014-05-01

    Over the past years, many applications based on laser-induced refractive index changes in the volume of transparent materials have been demonstrated. Ultrashort pulse lasers offer the possibility to process bulky transparent materials in three dimensions, suggesting that direct laser writing will play a decisive role in the development of integrated micro-optics. At the present time, applications such as 3D long term data storage or embedded laser marking are already into the phase of industrial development. However, a quantitative estimate of the laser-induced refractive index change is still very challenging to obtain. On another hand, several microscopy techniques have been recently developed to characterize bulk refractive index changes in-situ. They have been mostly applied to biological purposes. Among those, spatial light interference microscopy (SLIM), offers a very good robustness with minimal post acquisition data processing. In this paper, we report on using SLIM to measure fs-laser induced refractive index changes in different common glassy materials, such as fused silica and borofloat glass (B33). The advantages of SLIM over classical phase-contrast microscopy are discussed.

  10. Design of polarization-dipole-induced isotype heterojunction diodes for use in III-N hot electron transistors

    NASA Astrophysics Data System (ADS)

    Gupta, Geetak; Laurent, Matthew; Lu, Jing; Keller, Stacia; Mishra, Umesh K.

    2014-01-01

    The design of III-nitride-based hot electron transistors (HETs) is investigated using different diode design methodologies. Barrier-limited forward bias current and low reverse leakage current are demonstrated for the emitter-base diode using a barrier formed by a high-Al% AlGaN layer as a polarization-dipole layer. Two different base-collector diode designs are compared, one using 30% AlGaN as the barrier and the other using 10% InGaN as a polarization-dipole barrier. The InGaN polarization-dipole approach is shown to exhibit much lower reverse leakage currents. The impact of threading dislocation density on diode characteristics is also discussed.

  11. Photoisomerization-induced morphology and transparency transition in an azobenzene based two-component organogel system.

    PubMed

    Cao, Xinhua; Liu, Xue; Chen, Liming; Mao, Yueyuan; Lan, Haichuang; Yi, Tao

    2015-11-15

    A two-component gel containing long chain alkylated gallic acid (GA) and photochromic phenazopyridine (PAP) was prepared. The gel was thoroughly characterized by UV-visible and IR spectra, SEM and POM images, XRD diffraction and dynamic oscillatory measurements. The structure and transparency of the two-component gel can be reversibly changed by alternative UV light irradiation and warming in the palm of the hand. This kind of soft material has potential application in upscale surface functional materials.

  12. Modelling and simulation of a thermally induced optical transparency in a dual micro-ring resonator

    NASA Astrophysics Data System (ADS)

    Lydiate, Joseph

    2017-07-01

    This paper introduces the simulation and modelling of a novel dual micro-ring resonator. The geometric configuration of the resonators, and the implementation of a simulated broadband excitation source, results in the realization of optical transparencies in the combined through port output spectrum. The 130 nm silicon on insulator rib fabrication process is adopted for the simulation of the dual-ring configuration. Two titanium nitride heaters are positioned over the coupling regions of the resonators, which can be operated independently, to control the spectral position of the optical transparency. A third heater, centrally located above the dual resonator rings, can be used to red shift the entire spectrum to a required reference resonant wavelength. The free spectral range with no heater currents applied is 4.29 nm. For a simulated heater current of 7 mA (55.7 mW heater power) applied to one of the through coupling heaters, the optical transparency exhibits a red shift of 1.79 nm from the reference resonant wavelength. The ring-to-ring separation of approximately 900 nm means that it can be assumed that there is a zero ring-to-ring coupling field in this model. This novel arrangement has potential applications as a gas mass airflow sensor or a gas species identification sensor.

  13. Modelling and simulation of a thermally induced optical transparency in a dual micro-ring resonator.

    PubMed

    Lydiate, Joseph

    2017-07-01

    This paper introduces the simulation and modelling of a novel dual micro-ring resonator. The geometric configuration of the resonators, and the implementation of a simulated broadband excitation source, results in the realization of optical transparencies in the combined through port output spectrum. The 130 nm silicon on insulator rib fabrication process is adopted for the simulation of the dual-ring configuration. Two titanium nitride heaters are positioned over the coupling regions of the resonators, which can be operated independently, to control the spectral position of the optical transparency. A third heater, centrally located above the dual resonator rings, can be used to red shift the entire spectrum to a required reference resonant wavelength. The free spectral range with no heater currents applied is 4.29 nm. For a simulated heater current of 7 mA (55.7 mW heater power) applied to one of the through coupling heaters, the optical transparency exhibits a red shift of 1.79 nm from the reference resonant wavelength. The ring-to-ring separation of approximately 900 nm means that it can be assumed that there is a zero ring-to-ring coupling field in this model. This novel arrangement has potential applications as a gas mass airflow sensor or a gas species identification sensor.

  14. Modelling and simulation of a thermally induced optical transparency in a dual micro-ring resonator

    PubMed Central

    2017-01-01

    This paper introduces the simulation and modelling of a novel dual micro-ring resonator. The geometric configuration of the resonators, and the implementation of a simulated broadband excitation source, results in the realization of optical transparencies in the combined through port output spectrum. The 130 nm silicon on insulator rib fabrication process is adopted for the simulation of the dual-ring configuration. Two titanium nitride heaters are positioned over the coupling regions of the resonators, which can be operated independently, to control the spectral position of the optical transparency. A third heater, centrally located above the dual resonator rings, can be used to red shift the entire spectrum to a required reference resonant wavelength. The free spectral range with no heater currents applied is 4.29 nm. For a simulated heater current of 7 mA (55.7 mW heater power) applied to one of the through coupling heaters, the optical transparency exhibits a red shift of 1.79 nm from the reference resonant wavelength. The ring-to-ring separation of approximately 900 nm means that it can be assumed that there is a zero ring-to-ring coupling field in this model. This novel arrangement has potential applications as a gas mass airflow sensor or a gas species identification sensor. PMID:28791167

  15. Collision-Induced Absorption by Supermolecular Complexes from a New Potential Energy and Induced Dipole Surface, Suited for Calculations up to Thousands of Kelvin

    NASA Astrophysics Data System (ADS)

    Abel, Martin; Frommhold, Lothar; Wang, Fei; Gustafsson, Magnus; Li, Xiaoping; Hunt, Katharine L. C.

    2010-10-01

    Absorption by pairs of H2 molecules is an important opacity source in the atmospheres of the outer planets, and thus of special astronomical interest. The emission spectra of cool white dwarf stars differ significantly from the expected blackbody spectra, amongst other reasons due to absorption by H2-H2, H2-He, and H2-H collisional complexes in the stellar atmospheres. To model the radiative processes in these atmospheres, which have temperatures of several thousand kelvin, one needs accurate knowledge of the induced dipole (ID) and potential energy surfaces (PES) of such collisional complexes. These come from quantum-chemical calculations with the H2 bonds stretched or compressed far from equilibrium. Laboratory measurements of collision-induced (CI) absorption exist only at much lower temperature. For H2 pairs at room temperature, the calculated spectra of the rototranslational band, the fundamental band, and the first overtone match the experimental data very well. In addition, with the newly obtained IDS it became possible to reproduce the measurements in the far blue wing of the rototranslational spectrum of H2 at 77.5 K, as well as at 300 K. Similarly good agreement between theory and measurement is seen in the fundamental band of molecular deuterium at room temperature. Furthermore, we also show the calculated absorption spectra of H2-He at 600 K and of H2-H2 at 2,000 K, for which there are no experimental data for comparison.

  16. Electromagnetically induced transparency in double quantum dot under intense laser and magnetic fields: from Λ to Ξ configuration

    NASA Astrophysics Data System (ADS)

    Bejan, Doina

    2017-03-01

    We theoretically investigated the effects of non-resonant intense laser and magnetic fields on the optical properties of asymmetric GaAs/AlGaAs double quantum dot related to the occurrence of electromagnetically induced transparency, using compact density-matrix formalism and effective mass approximation. The chosen structure has the advantage to present x-lambda(Λ)-configuration or y-ladder(Ξ)-configuration for EIT occurrence, depending on lasers polarization, at low values of the non-resonant laser, and to change the configuration from Λ to Ξ at the increase of the x-polarized non-resonant laser intensity. We discussed in detail the influences of the control laser field intensity, non-resonant laser strength and polarization, and magnetic field intensity on the absorption coefficient, refraction index and group index. It is found that: (i) the control laser or the non-resonant laser at the same control laser intensity influences more the system being in x-Ξ-configuration than in x-Λ-configuration and have intermediate effects on y-Ξ-configuration; (ii) the magnetic field has the greatest influence on the system being in x-Λ-configuration and the lowest for y-Ξ-configuration; (iii) the increment of the non-resonant intense laser or magnetic fields induces a red-shift of the transparency windows and sub (super) luminal frequency intervals for the Λ-configuration but a blue-shift for both Ξ-configurations.

  17. Protective effect of transparent film dressing on proton therapy induced skin reactions

    PubMed Central

    2013-01-01

    Objective Proton therapy can result in clinically significant radiation dermatitis. In some clinical scenarios, such as lung or breast cancer, the risk of severe radiation dermatitis may limit beam arrangement and prescription doses. Patients undergoing proton therapy for prostate cancer commonly develop mild radiation dermatitis. Herein, we report the outcomes of two prostate cancer patients whose radiation dermatitis appears to have been substantially diminished by transparent film dressings (Beekley stickers). Methods This is a descriptive report of the skin toxicity observed in two patients undergoing proton therapy for prostate cancer at a single institution in 2011. A phantom dosimetric study was performed to evaluate the impact of a transparent film dressing on a beam’s spread out Bragg peak (SOBP). Results Two patients with low risk prostate cancer were treated with proton therapy to a total dose of 79.2Gy (RBE) in 1.8 Gy (RBE) fractions using two opposed lateral beams daily. Both patients had small circular (2.5 cm diameter) transparent adhesive markers placed on their skin to assist with daily alignment. Patient 1 had markers in place bilaterally for the entirety of treatment. Patient 2 had a marker in place for three weeks on one side and six weeks on the other. Over the course of therapy, both men developed typical Grade 1 radiation dermatitis (asymptomatic erythema) on their hips; however, in both patients, the erythema was substantially decreased beneath the markers. Patient 2 demonstrated less attenuation and thus greater erythema in the skin covered for three weeks compared to the skin covered for six weeks. The difference in skin changes between the covered and uncovered skin persisted for at least 1 month. A phantom study of double scattered beam SOBP with and without the marker in the beam path showed no gross dosimetric effect. Conclusions Transparent adhesive markers appear to have attenuated radiation dermatitis in these two patients without

  18. Damp-Heat Induced Degradation of Transparent Conducting Oxides for Thin Film Solar Cells (Presentation)

    SciTech Connect

    Pern, J.; Noufi, R.; Li, X.; DeHart, C.; To, B.

    2008-05-01

    The objectives are: (1) To achieve a high long-term performance reliability for the thin-film CIGS PV modules with more stable materials, device structure designs, and moisture-resistant encapsulation materials and schemes; (2) to evaluate the DH stability of various transparent conducting oxides (TCOs); (3) to identify the degradation mechanisms and quantify degradation rates; (4) to seek chemical and/or physical mitigation methods, and explore new materials. It's important to note that direct exposure to DH represents an extreme condition that a well-encapsulated thin film PV module may never experience.

  19. Interference-induced transparency and coherent control of quantum systems by frequency-chirped pulses

    NASA Astrophysics Data System (ADS)

    Nazarkin, A.; Netz, R.; Sauerbrey, R.

    2003-04-01

    A selective excitation technique based on light interference is proposed to control quantum systems by frequency-chirped laser fields. Interference of two identical, delayed and phase-shifted pulses is used to modulate the laser spectrum and project it onto the time domain. By adjusting the delay and phase shift, selected transitions can be brought into the “holes” of the spectrum and thus remain nonexcited. The possibility to selectively manipulate or even “shut down” resonant transitions, making the medium transparent to the field, is shown for the Rb atom.

  20. Giant Primeval Magnetic Dipoles

    NASA Astrophysics Data System (ADS)

    Thompson, Christopher

    2017-07-01

    Macroscopic magnetic dipoles are considered cosmic dark matter. Permanent magnetism in relativistic field structures can involve some form of superconductivity, one example being current-carrying string loops (“springs”) with vanishing net tension. We derive the cross-section for free classical dipoles to collide, finding it depends weakly on orientation when mutual precession is rapid. The collision rate of “spring” loops with tension { T }˜ {10}-8{c}4/G in galactic halos approaches the measured rate of fast radio bursts (FRBs) if the loops compose most of the dark matter. A large superconducting dipole (LSD) with mass ˜1020 g and size ˜1 mm will form a ˜100 km magnetosphere moving through interstellar plasma. Although hydromagnetic drag is generally weak, it is strong enough to capture some LSDs into long-lived rings orbiting supermassive black holes (SMBHs) that form by the direct collapse of massive gas clouds. Repeated collisions near young SMBHs could dominate the global collision rate, thereby broadening the dipole mass spectrum. Colliding LSDs produce tiny, hot electromagnetic explosions. The accompanying paper shows that these explosions couple effectively to propagating low-frequency electromagnetic modes, with output peaking at 0.01-1 THz. We describe several constraints on, and predictions of, LSDs as cosmic dark matter. The shock formed by an infalling LSD triggers self-sustained thermonuclear burning in a C/O (ONeMg) white dwarf (WD) of mass ≳1 M ⊙ (1.3 M ⊙). The spark is generally located off the center of the WD. The rate of LSD-induced explosions matches the observed rate of Type Ia supernovae.

  1. Fano Transparency in Rounded Nanocube Dimers Induced by Gap Plasmon Coupling.

    PubMed

    Pellarin, Michel; Ramade, Julien; Rye, Jan Michael; Bonnet, Christophe; Broyer, Michel; Lebeault, Marie-Ange; Lermé, Jean; Marguet, Sylvie; Navarro, Julien R G; Cottancin, Emmanuel

    2016-12-27

    Homodimers of noble metal nanocubes form model plasmonic systems where the localized plasmon resonances sustained by each particle not only hybridize but also coexist with excitations of a different nature: surface plasmon polaritons confined within the Fabry-Perot cavity delimited by facing cube surfaces (i.e., gap plasmons). Destructive interference in the strong coupling between one of these highly localized modes and the highly radiating longitudinal dipolar plasmon of the dimer is responsible for the formation of a Fano resonance profile and the opening of a spectral window of anomalous transparency for the exciting light. We report on the clear experimental evidence of this effect in the case of 50 nm silver and 160 nm gold nanocube dimers studied by spatial modulation spectroscopy at the single particle level. A numerical study based on a plasmon mode analysis leads us to unambiguously identify the main cavity mode involved in this process and especially the major role played by its symmetry. The Fano depletion dip is red-shifted when the gap size is decreasing. It is also blue-shifted and all the more pronounced that the cube edge rounding is large. Combining nanopatch antenna and plasmon hybridization descriptions, we quantify the key role of the face-to-face distance and the cube edge morphology on the spectral profile of the transparency dip.

  2. Control of Radiative Exciton Recombination by Charge Transfer Induced Surface Dipoles in MoS2 and WS2 Monolayers

    PubMed Central

    Hu, Peng; Ye, Jun; He, Xuexia; Du, Kezhao; Zhang, Keke K.; Wang, Xingzhi; Xiong, Qihua; Liu, Zheng; Jiang, Hui; Kloc, Christian

    2016-01-01

    Due to the two dimensional confinement of electrons in a monolayer of 2D materials, the properties of monolayer can be controlled by electrical field formed on the monolayer surface. F4TCNQ was evaporated on MoS2 and WS2 monolayer forming dipoles between strong acceptor, F4TCNQ, and monolayers of MoS2 or WS2. The strong acceptor attracts electrons (charge transfer) and decreases the number of the ionized excitons. Free excitons undergo radiative recombination in both MoS2 and WS2. Moreover, the photoluminescence enhancement is stronger in WS2 where the exciton-phonon coupling is weaker. The theoretical model indicates that the surface dipole controls the radiative exciton recombination and enhances photoluminescence radiation. Deposition of F4TCNQ on the 2D monolayers enables a convenient control of the radiative exciton recombination and leads to the applications of these materials in lasers or LEDs. PMID:27053440

  3. Dipole moments of the tau-lepton and Z-Z‧ mixing angle induced in a 331 model

    NASA Astrophysics Data System (ADS)

    Gutiérrez-Rodríguez, A.; Hernández-Ruíz, M. A.; Castañeda-Almanza, C. P.

    2013-03-01

    Using as an input the data obtained by the L3 and OPAL Collaborations for the reaction e+e- → τ+τ-γ at the Z-pole, we obtained bounds on the electromagnetic and weak dipole moments of the tau-lepton in the context of a 331 model. Our bounds on the electromagnetic moments are consistent with the bounds obtained by the L3 and OPAL Collaborations for the reaction e+e- → τ+τ-γ. We also obtained bounds on the tau weak dipole moments which are consistent with the bounds obtained recently by the DELPHI, ALEPH and BELLE Collaborations from the reaction e+e- → τ+τ-. In addition, we obtained a limit on the Z-Z‧ mixing angle of the 331 model: -3.92 × 10-3 ⩽ ϕ ⩽ 1.30 × 10-4, which is competitive with those reported in the literature. Our work complements other studies on the electromagnetic and weak dipole moments of the tau-lepton and on the Z-Z‧ mixing angle.

  4. Independently tunable dual-band plasmonically induced transparency based on hybrid metal-graphene metamaterials at mid-infrared frequencies.

    PubMed

    Sun, Chen; Dong, Zhewei; Si, Jiangnan; Deng, Xiaoxu

    2017-01-23

    A tunable dual-band plasmonically induced transparency (PIT) device based on hybrid metal-graphene nanostructures is proposed theoretically and numerically at mid-infrared frequencies, which is composed of two kinds of gold dolmen-like structures with different sizes placed on separate graphene interdigitated finger sets respectively. The coupled Lorentz oscillator model is used to explain the physical mechanism of the PIT effect at multiple frequency domains. The finite-difference time-domain (FDTD) solutions are employed to simulate the characteristics of the hybrid metal-graphene dual-band PIT device. The simulated spectral locations of multiple transparency peaks are separately and dynamically modulated by varying the Fermi energy of corresponding graphene finger set, which is in good accordance with the theoretical analysis. Distinguished from the conventional metallic PIT devices, multiple PIT resonances in the hybrid metal-graphene PIT device are independently modulated by electrostatically changing bias voltages applied on corresponding graphene fingers, which can be widely applied in optical information processing as tunable sensors, switches, and filters.

  5. Active control of electromagnetically induced transparency with dual dark mode excitation pathways using MEMS based tri-atomic metamolecules

    NASA Astrophysics Data System (ADS)

    Pitchappa, Prakash; Manjappa, Manukumara; Ho, Chong Pei; Singh, Ranjan; Singh, Navab; Lee, Chengkuo

    2016-11-01

    We report experimental results of the active switching of electromagnetically induced transparency (EIT) analogue by controlling the dark mode excitation pathways in a microelectromechanical system based tri-atomic metamolecule, operating in the terahertz spectral region. The tri-atomic metamolecule consists of two bright cut wire resonators (CWRs) on either side of the dark split ring resonators (SRRs). Each of the CWRs can independently excite the dark inductive-capacitive resonance mode of the SRRs through inductive coupling, and this allows for the dual pathways of dark mode excitation. The CWRs are made movable along the out-of-plane direction and electrically isolated to achieve selective reconfiguration. Hence, by controlling the physical position of these CWRs, the excitation pathways can be actively reconfigured. This enables the strong excitation of EIT analogue at 0.65 THz, only when one of the pathways is made accessible. Moreover, the transparency peak is completely modulated when both pathways are made either inaccessible or equally accessible. The proposed approach of realizing independent control of constituent resonators in a multi-resonator coupled system, enables the realization of efficient slow light devices and tunable high-Q resonators in terahertz spectral region.

  6. Electromagnetically induced transparency and evolution of a two-level system under chaotic field of arbitrary intensity

    NASA Astrophysics Data System (ADS)

    Kofman, A. G.

    2001-11-01

    The electromagnetically induced transparency (EIT) with a (near-)resonant chaotic (amplitude-phase fluctuating, Gaussian-Markovian) coupling field is studied theoretically. The Fourier transform of the steady-state EIT spectrum, which determines a nonstationary probe absorption, is also considered. This quantity equals the average diagonal element of the (reduced) evolution operator of the coupled transition (the evolution function). The exact solution in the form of a continued fraction is obtained and used to perform numerical calculations. Moreover, a number of approximate analytical results are obtained, which, together with the results of previous publications, describe the EIT and the evolution function in all possible regimes. In particular, in the constructive-interference case the EIT increases with the coupling-field bandwidth ν at sufficiently small ν. For a strong field, the maximum of the transparency as a function of ν is less than that for a monochromatic field of the same average intensity. In contrast, for a weak field, there is a range of ν values, where the field fluctuations do not affect the EIT. The latter result is shown to hold for a broad class of stochastic fields.

  7. Kinetic effects on the transition to relativistic self-induced transparency in laser-driven ion acceleration

    NASA Astrophysics Data System (ADS)

    Siminos, Evangelos; Svedung Wettervik, Benjamin; Grech, Mickael; Fülöp, Tünde

    2016-10-01

    We study kinetic effects responsible for the transition to relativistic self-induced transparency in the interaction of a circularly-polarized laser-pulse with an overdense plasma and their relation to hole-boring and ion acceleration. It is shown, using particle-in-cell simulations and an analysis of separatrices in single-particle phase-space, that this transition is mediated by the complex interplay of fast electron dynamics and ion motion at the initial stage of the interaction. It thus depends on the ion charge-to-mass ratio and can be controlled by varying the laser temporal profile. Moreover, we find a new regime in which a transition from relativistic transparency to hole-boring occurs dynamically during the course of the interaction. It is shown that, for a fixed laser intensity, this dynamic transition regime allows optimal ion acceleration in terms of both energy and energy spread. This work was supported by the Knut and Alice Wallenberg Foundation (pliona project) and the European Research Council (ERC-2014-CoG Grant 647121).

  8. Transfer and computation of optical topological charges via light pulse buffer memory in an electromagnetically-induced-transparency solid

    NASA Astrophysics Data System (ADS)

    Zhai, Zhaohui; Li, Zhixiang; Xu, Jingjun; Zhang, Guoquan

    2013-09-01

    We verified that optical topological charges are conserved in a two-step light-pulse storage and retrieval process based on the electromagnetically-induced-transparency (EIT) effect in a Pr3+:Y2SiO5 crystal. Based on this conservation law, one could transfer topological charges from the interacting beams, which may not be overlapped in space and time domains, to the targeted output signal beam, and algebraic operations such as summation and subtraction of topological charges carried by the interacting beams were demonstrated via the EIT-assisted two-step light-pulse storage-retrieval process. The results may be useful for classical and quantum information processing based on optical topological charge buffer memory in EIT media.

  9. Electromagnetically induced transparency and four-wave mixing in a cold atomic ensemble with large optical depth

    NASA Astrophysics Data System (ADS)

    Geng, J.; Campbell, G. T.; Bernu, J.; Higginbottom, D. B.; Sparkes, B. M.; Assad, S. M.; Zhang, W. P.; Robins, N. P.; Lam, P. K.; Buchler, B. C.

    2014-11-01

    We report on the delay of optical pulses using electromagnetically induced transparency (EIT) in an ensemble of cold atoms with an optical depth exceeding 500. To identify the regimes in which four-wave mixing (4WM) impacts on EIT behaviour, we conduct the experiment in both 85Rb and 87Rb. Comparison with theory shows excellent agreement in both isotopes. In 87Rb negligible 4WM was observed and we obtained one pulse-width of delay with 50% efficiency. In 85Rb 4WM contributes to the output. In this regime we achieve a delay-bandwidth product of 3.7 at 50% efficiency, allowing temporally multimode delay, which we demonstrate by compressing two pulses into the memory medium.

  10. Efficient reflection via four-wave mixing in a Doppler-free electromagnetically-induced-transparency gas system

    SciTech Connect

    Zhou, Hai-Tao; Wang, Dan; Zhang, Jun-Xiang; Wang, Da-Wei; Zhu, Shi-Yao

    2011-11-15

    We experimentally demonstrate the high-efficiency reflection of a probe field in {Lambda}-type three-level atoms of cesium vapor driven by two counterpropagating coupling fields. More than 60% of reflection efficiency is observed at the phase-matching angle. The underlying mechanism theoretically is investigated as the four-wave mixing is enhanced by the electromagnetically-induced transparency. Both of the two Doppler-free two-photon resonances (one for the probe and co-propagating fields, the other for the reflected and the counterpropagation fields) play an important role in satisfying the phase matching in the reflection direction. The phase compensation due to the anomalous dispersion and the decrease of effective absorption length in the atomic system allow the efficient reflection to be observed in a wide range of incident angles of the probe field and detunings of the coupling field.

  11. Weak-light rogue waves, breathers, and their active control in a cold atomic gas via electromagnetically induced transparency

    NASA Astrophysics Data System (ADS)

    Liu, Junyang; Hang, Chao; Huang, Guoxiang

    2016-06-01

    We propose a scheme to demonstrate the existence of optical Peregrine rogue waves and Akhmediev and Kuznetsov-Ma breathers and realize their active control via electromagnetically induced transparency (EIT). The system we suggest is a cold, Λ -type three-level atomic gas interacting with a probe and a control laser fields and working under EIT condition. We show that, based on EIT with an incoherent optical pumping, which can be used to cancel optical absorption, (1+1)-dimensional optical Peregrine rogue waves, Akhmediev breathers, and Kuznetsov-Ma breathers can be generated with very low light power. In addition, we demonstrate that the Akhmediev and Kuznetsov-Ma breathers in (2+1)-dimensions obtained can be actively manipulated by using an external magnetic field. As a result, these breathers can display trajectory deflections and bypass obstacles during propagation.

  12. Matter-Wave-Optical-Wave Mixing-Induced Transparency and a Nonhyperbolic Matter-Wave Quasisoliton in Quantum Gases.

    PubMed

    Li, Yan; Zhu, Chengjie; Garrett, W R; Hagley, E W; Deng, L

    2017-01-06

    The realization of atomic quantum gases has brought out surprising effects that have no correspondence in nonlinear optics with thermal gases, presenting intriguing and exciting challenges to the research discipline of nonlinear optics which has matured since the invention of the laser. Here, we show an unexpected optical wave-mixing gain cancellation effect in a quantum gas that restricts an, otherwise, strongly enhanced backward-propagating light-matter wave-mixing process. This results in a wave-mixing induced transparency and a nonhyperbolic quasi-matter-wave soliton that opens new research opportunities in hydrodynamic fluid research of degenerate quantum gases, such as phonon scattering in a two-dimensional sonic black hole horizon.

  13. Observation of electromagnetically induced transparency in six-level Rb atoms and theoretical simulation of the observed spectra

    NASA Astrophysics Data System (ADS)

    Bhattacharyya, Dipankar; Ghosh, Arindam; Bandyopadhyay, Amitava; Saha, Satyajit; De, Sankar

    2015-09-01

    We report the observation of electromagnetically induced transparency (EIT) in a six-level Λ-type system in atomic Rb vapor containing both 87Rb and 85Rb. The experimental observation includes five velocity selective optically pumped (VSOP) absorption dips for both 87Rb and 85Rb. The EIT signal appears on the background of one such VSOP absorption dips. The measured EIT linewidth ({Γ }t) shows sub-natural ({Γ }t \\lt Γ ) values for both lower and higher values of pump Rabi-frequencies. The density matrix based theoretical model for the six-level system is developed and solved numerically by taking into account the Doppler broadening. A complete analytical solution (non perturbative) for a three level Λ-type system has been obtained and compared with the experimentally observed sub-natural EIT linewidth. The simulated spectra are in good agreement with the experimental findings.

  14. FIFTH SEMINAR IN MEMORY OF D.N. KLYSHKO: Light scattering under conditions of nonstationary electromagnetically induced transparency

    NASA Astrophysics Data System (ADS)

    Larionov, N. V.; Sokolov, I. M.

    2007-12-01

    The propagation of probe radiation pulses in ultracold atomic ensembles is studied theoretically under conditions of electromagnetically induced transparency. The pulse 'stopping' process is considered which takes place upon nonadiabatic switching off and subsequent switching on the control field. We analysed the formation of an inverted recovered probe radiation pulse, i.e. the pulse propagating in the direction opposite to the propagation direction before the pulse stopping. Based on this analysis, a scheme is proposed for lidar probing atomic or molecular clouds in which the probe pulse penetrates into a cloud over the specified depth, while information on the cloud state is obtained from the parameters of the inverted pulse. Calculations are performed for an ensemble of 87Rb atoms.

  15. Sub-wavelength imaging and field mapping via electromagnetically induced transparency and Autler-Townes splitting in Rydberg atoms

    SciTech Connect

    Holloway, Christopher L. Gordon, Joshua A.; Schwarzkopf, Andrew; Anderson, David A.; Miller, Stephanie A.; Thaicharoen, Nithiwadee; Raithel, Georg

    2014-06-16

    We present a technique for measuring radio-frequency (RF) electric field strengths with sub-wavelength resolution. We use Rydberg states of rubidium atoms to probe the RF field. The RF field causes an energy splitting of the Rydberg states via the Autler-Townes effect, and we detect the splitting via electromagnetically induced transparency (EIT). We use this technique to measure the electric field distribution inside a glass cylinder with applied RF fields at 17.04 GHz and 104.77 GHz. We achieve a spatial resolution of ≈100 μm, limited by the widths of the laser beams utilized for the EIT spectroscopy. We numerically simulate the fields in the glass cylinder and find good agreement with the measured fields. Our results suggest that this technique could be applied to image fields on a small spatial scale over a large range of frequencies, up into the sub-terahertz regime.

  16. Line shapes in a plasmonic waveguide system based on plasmon-induced transparency and its application in nanosensor

    NASA Astrophysics Data System (ADS)

    He, Jialing; Yang, Shu

    2016-12-01

    A compact plasmonic coupled-resonator structure is investigated using a finite element method, which consists of a ring resonator and a stub coupled with a metal-insulator-metal (MIM) waveguide. Simulation results show that due to the resonant enhancement effect in this system, the plasmon-induced transparency (PIT) occurs and a sharp asymmetric Fano line arise in the transmission spectra by adjusting the parameters of the structure. Meanwhile, the position of the transmission peak can be controlled in any resonance mode by changing the depth of the stub, which is different from the previous researches. The physical features provide a high refractive index sensing with a sensitivity of 1100 nm/RIU and a figure of merit (FOM) of 42550. Moreover, dual resonance peaks are realized by adding an extra ring resonator placed on the stub. The proposed structures may have wide applications in photonic-integrated circuits and the on-chip nanosensors.

  17. Current density characteristics in the studies of electromagnetically induced transparency in a GaAs/GaAlAs quantum well

    NASA Astrophysics Data System (ADS)

    Jayarubi, J.; Peter, A. John

    2017-05-01

    Confinement potential profiles due to conduction and valence bands are obtained in a Ga0.7Al0.3As/ GaAs/ Ga0.7Al0.3As using variation formulism. The free electron distribution is carried out. The confined energy eigenvalue and its corresponding wavefunctions of charge carriers are found using self-consistent method. The confined energies with the geometrical confinement are computed. The potentials due to charges are done by Poisson equation. The effects of dielectric mismatch between the GaAs and GaAlAs semiconductors are introduced in the effective potential expressions. Transfer matrix method is employed to obtain the respective energies. The transmission probability is obtained for a constant well size. The high current density characteristics as a function of applied voltage is investigated. This investigation on the electromagnetically induced transparency in the photonic material will exploit in fabricating novel nonlinear optical devices in future.

  18. Matter-Wave-Optical-Wave Mixing-Induced Transparency and a Nonhyperbolic Matter-Wave Quasisoliton in Quantum Gases

    NASA Astrophysics Data System (ADS)

    Li, Yan; Zhu, Chengjie; Garrett, W. R.; Hagley, E. W.; Deng, L.

    2017-01-01

    The realization of atomic quantum gases has brought out surprising effects that have no correspondence in nonlinear optics with thermal gases, presenting intriguing and exciting challenges to the research discipline of nonlinear optics which has matured since the invention of the laser. Here, we show an unexpected optical wave-mixing gain cancellation effect in a quantum gas that restricts an, otherwise, strongly enhanced backward-propagating light-matter wave-mixing process. This results in a wave-mixing induced transparency and a nonhyperbolic quasi-matter-wave soliton that opens new research opportunities in hydrodynamic fluid research of degenerate quantum gases, such as phonon scattering in a two-dimensional sonic black hole horizon.

  19. Electromagnetically induced transparency and nonlinear pulse propagation in a combined tripod and Λ atom-light coupling scheme

    NASA Astrophysics Data System (ADS)

    Hamedi, H. R.; Ruseckas, J.; Juzeliūnas, G.

    2017-09-01

    We consider propagation of a probe pulse in an atomic medium characterized by a combined tripod and Lambda (Λ) atom-light coupling scheme. The scheme involves three atomic ground states coupled to two excited states by five light fields. It is demonstrated that dark states can be formed for such an atom-light coupling. This is essential for formation of the electromagnetically induced transparency (EIT) and slow light. In the limiting cases the scheme reduces to conventional Λ- or N-type atom-light couplings providing the EIT or absorption, respectively. Thus, the atomic system can experience a transition from the EIT to the absorption by changing the amplitudes or phases of control lasers. Subsequently the scheme is employed to analyze the nonlinear pulse propagation using the coupled Maxwell-Bloch equations. It is shown that a generation of stable slow light optical solitons is possible in such a five-level combined tripod and Λ atomic system.

  20. Dynamically Tunable Plasmon-Induced Transparency in On-chip Graphene-Based Asymmetrical Nanocavity-Coupled Waveguide System

    NASA Astrophysics Data System (ADS)

    Qiu, Pingping; Qiu, Weibin; Lin, Zhili; Chen, Houbo; Ren, Junbo; Wang, Jia-Xian; Kan, Qiang; Pan, Jiao-Qing

    2017-05-01

    A graphene-based on-chip plasmonic nanostructure composed of a plasmonic bus waveguide side-coupled with a U-shaped and a rectangular nanocavities has been proposed and modeled by using the finite element method in this paper. The dynamic tunability of the plasmon-induced transparency (PIT) windows has been investigated. The results reveal that the PIT effects can be tuned via modifying the chemical potential of the nanocavities and plasmonic bus waveguide or by varying the geometrical parameters including the location and width of the rectangular nanocavity. Further, the proposed plasmonic nanostructure can be used as a plasmonic refractive index sensor with a sensing sensibility of 333.3 nm/refractive index unit (RIU) at the the PIT transmission peak. Slow light effect is also realized in the PIT system. The proposed nanostructure may pave a new way towards the realization of graphene-based on-chip integrated nanophotonic devices.

  1. Zero to π Continuously Controllable Cross Phase Modulation in Doppler Broadened N-Type Electromagnetically Induced Transparency Medium.

    PubMed

    Li, R B; Zhu, C J; Deng, L; Hagley, E W

    2015-10-01

    We demonstrate an observation of zero to π continuously controllable cross-phase-modulation based on N-type electromagnetically induced transparency scheme in a room-temperature (87)Rb vapor. We theoretically and experimentally show that the signal field acquires a π phase shift compared with the reference light in the presence of the phase-control field. Using the method of the optical Mach-Zehnder interferometer, we demonstrate that a zero to π continuously controllable phase gate can be built by modulating the phase-control field. In addition, our theoretical calculation agrees well with the experimental observation, and the results presented in this work hold the potential applications for the orthogonal polarization/vector gate in the quantum information processing.

  2. Zero to π Continuously Controllable Cross Phase Modulation in Doppler Broadened N-Type Electromagnetically Induced Transparency Medium

    PubMed Central

    Li, R. B.; Zhu, C. J.; Deng, L.; Hagley, E. W.

    2016-01-01

    We demonstrate an observation of zero to π continuously controllable cross-phase-modulation based on N-type electromagnetically induced transparency scheme in a room-temperature 87Rb vapor. We theoretically and experimentally show that the signal field acquires a π phase shift compared with the reference light in the presence of the phase-control field. Using the method of the optical Mach-Zehnder interferometer, we demonstrate that a zero to π continuously controllable phase gate can be built by modulating the phase-control field. In addition, our theoretical calculation agrees well with the experimental observation, and the results presented in this work hold the potential applications for the orthogonal polarization/vector gate in the quantum information processing. PMID:27453675

  3. Dynamically Tunable Plasmon-Induced Transparency in On-chip Graphene-Based Asymmetrical Nanocavity-Coupled Waveguide System.

    PubMed

    Qiu, Pingping; Qiu, Weibin; Lin, Zhili; Chen, Houbo; Ren, Junbo; Wang, Jia-Xian; Kan, Qiang; Pan, Jiao-Qing

    2017-12-01

    A graphene-based on-chip plasmonic nanostructure composed of a plasmonic bus waveguide side-coupled with a U-shaped and a rectangular nanocavities has been proposed and modeled by using the finite element method in this paper. The dynamic tunability of the plasmon-induced transparency (PIT) windows has been investigated. The results reveal that the PIT effects can be tuned via modifying the chemical potential of the nanocavities and plasmonic bus waveguide or by varying the geometrical parameters including the location and width of the rectangular nanocavity. Further, the proposed plasmonic nanostructure can be used as a plasmonic refractive index sensor with a sensing sensibility of 333.3 nm/refractive index unit (RIU) at the the PIT transmission peak. Slow light effect is also realized in the PIT system. The proposed nanostructure may pave a new way towards the realization of graphene-based on-chip integrated nanophotonic devices.

  4. Tunable plasmon-induced transparency in a grating-coupled double-layer graphene hybrid system at far-infrared frequencies.

    PubMed

    Zhao, Xiaolei; Zhu, Lin; Yuan, Cai; Yao, Jianquan

    2016-12-01

    A grating-coupled double-layer graphene hybrid system is proposed to investigate the plasmon-induced transparency effect at far-infrared frequencies. Based on the guided mode resonance principle, a diffractive grating is used to couple the normally incident waves and excite the plasmonic resonances on two graphene films separated by a spacer, thereby avoiding the need for patterning graphene. It is found that the origin of the observed transparency window transforms from Autler-Townes splitting to electromagnetically induced transparency with the increase of the separation distance between the two graphene films. The tunability of this hybrid system is also investigated via varying the Fermi energy in graphene. The proposed hybrid system has potential applications in tunable switches, sensors, and slow light devices and may open up new avenues for constructing easy-to-fabricate graphene-based plasmonic devices.

  5. Theoretical and experimental examination of particle-particle interaction effects on induced dipole moments and dielectrophoretic responses of multiple particle chains.

    PubMed

    Moncada-Hernandez, Hector; Nagler, Eliot; Minerick, Adrienne R

    2014-07-01

    Dielectrophoresis (DEP), an electrokinetic phenomenon based on particle polarizations in nonuniform electric fields, is increasingly employed for particle and cell characterizations and manipulations in microdevices. However, particle number densities are rarely varied and particle-particle interactions are largely overlooked, but both affect particle's effective polarizations by changing the local electric field, which directly impacts particle assembly into chains. This work examines theoretical and experimental particle-particle interactions and dielectrophoretic responses in nonuniform electric fields, then presents individual and chain velocities of spherical polystyrene microparticles and red blood cells (RBCs) under DEP forces in a modified quadruple electrode microdevice. Velocities are independently compared between 1, 2, 3, and 4 polystyrene beads and RBCs assembled into chains aligned with the electric field. Simulations compared induced dipole moments for particles experiencing the same (single point) and changing (multiple points) electric fields. Experiments and simulations are compared by plotting DEP velocities versus applied signal frequency from 1 kHz to 80 MHz. Simulations indicate differences in the DEP force exerted on each particle according to chain position. Simulations and experiments show excellent qualitative agreement; chains with more particles experienced a decrease in the DEP response for both polystyrene beads and RBCs. These results advance understanding of the extent that induced dipole polarizations with multiple particle chains affect observed behaviors in electrokinetic cellular diagnostic systems.

  6. Few-cycle solitons in the medium with permanent dipole moment under conditions of the induced birefringence

    NASA Astrophysics Data System (ADS)

    Sazonov, S. V.

    2016-12-01

    Propagation of electromagnetic pulse in the birefringent medium consisting of symmetric and asymmetrical molecules is investigated. Stationary quantum states of asymmetrical molecules have the permanent dipole moment. Under considered conditions the ordinary pulse component excites quantum transitions between stationary states. The extraordinary component, besides, causes a dynamic chirp of frequencies of these transitions. The new solitonic modes of propagation of the half- and single-period pulses are found. The solitonic mechanism of simultaneous generation of the second and zero harmonics in the modes of "bright" and "dark" solitons is analyzed.

  7. /ital In/ /ital situ/ determination of induced dipole moments of pure and membrane-bound retinal chromophores

    SciTech Connect

    Rasing, T.; Huang, J.; Lewis, A.; Stehlin, T.; Shen, Y. R.

    1989-08-01

    By using the technique of optical second-harmonic generation, we havesucceeded in obtaining the orientation, spectrum, and the change in dipolemoment upon optical excitation for monolayers of retinal chromophores, whichare of relevance for visual excitation. The change in dipole moment of thechromophore embedded in the purple membrane of /ital Halobacterium/ /ital halobium/ isfound to be identical to that of the free chromophore. The spectrum ofall-trans retinal monolayers exhibits a subsidiary one-photon forbidden peak inaddition to the main absorption peak.

  8. Dipole-mode vector solitons

    PubMed

    Garcia-Ripoll; Perez-Garcia; Ostrovskaya; Kivshar

    2000-07-03

    We find a new type of optical vector soliton that originates from trapping of a dipole mode by the soliton-induced waveguides. These solitons, which appear as a consequence of the vector nature of the two-component system, are more stable than the previously found optical vortex solitons and represent a new type of extremely robust nonlinear vector structure.

  9. A meridional dipole in premonsoon Bay of Bengal tropical cyclone activity induced by ENSO: TROPICAL CYCLONES, MONSOON AND ENSO

    SciTech Connect

    Balaguru, Karthik; Leung, L. Ruby; Lu, Jian; Foltz, Gregory R.

    2016-06-27

    Analysis of Bay of Bengal tropical cyclone (TC) track data for the month of May during 1980-2013 reveals a meridional dipole in TC intensification: TC intensification rates increased in the northern Bay and decreased in the southern Bay. The dipole was driven by an increase in low-level vorticity and atmospheric humidity in the northern Bay, making the environment more favorable for TC intensification, and enhanced vertical wind shear in the southern Bay, tending to reduce TC development. These environmental changes were associated with a strengthening of the monsoon circulation for the month of May, driven by a La Nin˜a-like shift in tropical Pacific SSTs andassociated tropical wave dynamics. Analysis of a suite of climate models fromthe CMIP5 archive for the 150-year historical period shows that most models correctly reproduce the link between ENSO and Bay of Bengal TC activity through the monsoon at interannual timescales. Under the RCP 8.5 scenario the same CMIP5 models produce an El Nin˜o like warming trend in the equatorial Pacific, tending to weaken the monsoon circulation. These results suggest

  10. A large dipole moment to promote gelation for 4-nitrophenylacrylonitrile derivatives with gelation-induced emission enhancement properties.

    PubMed

    Xue, Pengchong; Yao, Boqi; Zhang, Yuan; Chen, Peng; Li, Kechang; Liu, Baijun; Lu, Ran

    2014-09-28

    A series of 4-nitrophenylacrylonitrile and phenylacrylonitrile derivatives consisting of a carbazole moiety was synthesized. Some of these derivatives with longer alkyl chains and a nitro group could gelatinize some organic solvents, such as ethanol, n-butanol, ethyl acetate, and DMSO. By contrast, phenylacrylonitrile derivatives did not form gels in measured solvents. This result proved that the electron-withdrawing nitro moiety was important for gel formation because it conferred the molecules with large dipole moments, which enhanced the intermolecular interaction. Analyses by UV-vis absorption, X-ray diffraction, and scanning electron microscopy showed that the gelator molecules could self-assemble into one-dimensional nanofibers with layer packing, which further twisted into thicker fibers and formed three-dimensional networks in the gel phase. The single crystal structure of C4CNPA implied that the gelators might adopt an anti-parallel molecular stacking because of their larger ground-state dipole moment. Interestingly, the organogels had enhanced fluorescence relative to solutions at the same concentrations.

  11. Airborne Transparencies.

    ERIC Educational Resources Information Center

    Horne, Lois Thommason

    1984-01-01

    Starting from a science project on flight, art students discussed and investigated various means of moving in space. Then they made acetate illustrations which could be used as transparencies. The projection phenomenon made the illustrations look airborne. (CS)

  12. The dipole repeller

    NASA Astrophysics Data System (ADS)

    Hoffman, Yehuda; Pomarède, Daniel; Tully, R. Brent; Courtois, Hélène M.

    2017-01-01

    Our Local Group of galaxies is moving with respect to the cosmic microwave background (CMB) with a velocity 1 of V CMB = 631 ± 20 km s‑1 and participates in a bulk flow that extends out to distances of ~20,000 km s‑1 or more 2-4 . There has been an implicit assumption that overabundances of galaxies induce the Local Group motion 5-7 . Yet underdense regions push as much as overdensities attract 8 , but they are deficient in light and consequently difficult to chart. It was suggested a decade ago that an underdensity in the northern hemisphere roughly 15,000 km s‑1 away contributes significantly to the observed flow 9 . We show here that repulsion from an underdensity is important and that the dominant influences causing the observed flow are a single attractor — associated with the Shapley concentration — and a single previously unidentified repeller, which contribute roughly equally to the CMB dipole. The bulk flow is closely anti-aligned with the repeller out to 16,000 ± 4,500 km s‑1. This 'dipole repeller' is predicted to be associated with a void in the distribution of galaxies.

  13. Optomechanically induced transparency in multi-cavity optomechanical system with and without one two-level atom

    NASA Astrophysics Data System (ADS)

    Sohail, Amjad; Zhang, Yang; Zhang, Jun; Yu, Chang-Shui

    2016-06-01

    We analytically study the optomechanically induced transparency (OMIT) in the N-cavity system with the Nth cavity driven by pump, probing laser fields and the 1st cavity coupled to mechanical oscillator. We also consider that one atom could be trapped in the ith cavity. Instead of only illustrating the OMIT in such a system, we are interested in how the number of OMIT windows is influenced by the cavities and the atom and what roles the atom could play in different cavities. In the resolved sideband regime, we find that, the number of cavities precisely determines the maximal number of OMIT windows. It is interesting that, when the two-level atom is trapped in the even-labeled cavity, the central absorptive peak (odd N) or dip (even N) is split and forms an extra OMIT window, but if the atom is trapped in the odd-labeled cavity, the central absorptive peak (odd N) or dip (even N) is only broadened and thus changes the width of the OMIT windows rather than induces an extra window.

  14. Optomechanically induced transparency in multi-cavity optomechanical system with and without one two-level atom.

    PubMed

    Sohail, Amjad; Zhang, Yang; Zhang, Jun; Yu, Chang-Shui

    2016-06-28

    We analytically study the optomechanically induced transparency (OMIT) in the N-cavity system with the Nth cavity driven by pump, probing laser fields and the 1st cavity coupled to mechanical oscillator. We also consider that one atom could be trapped in the ith cavity. Instead of only illustrating the OMIT in such a system, we are interested in how the number of OMIT windows is influenced by the cavities and the atom and what roles the atom could play in different cavities. In the resolved sideband regime, we find that, the number of cavities precisely determines the maximal number of OMIT windows. It is interesting that, when the two-level atom is trapped in the even-labeled cavity, the central absorptive peak (odd N) or dip (even N) is split and forms an extra OMIT window, but if the atom is trapped in the odd-labeled cavity, the central absorptive peak (odd N) or dip (even N) is only broadened and thus changes the width of the OMIT windows rather than induces an extra window.

  15. Morphology of elastase-induced cerebral aneurysm model in rabbit and rapid prototyping of elastomeric transparent replicas.

    PubMed

    Seong, Jaehoon; Sadasivan, Chander; Onizuka, Masanari; Gounis, Matthew J; Christian, Fletcher; Miskolczi, Laszlo; Wakhloo, Ajay K; Lieber, Baruch B

    2005-01-01

    In this work, we describe a methodology to fabricate transparent elastomeric vascular replicas using rapid prototyping techniques. First, the three-dimensional morphology of an elastase-induced aneurysm model in rabbit is acquired. The morphology is reconstructed from in vivo rotational angiography and it is compared with three-dimensional reconstructions obtained by computerized tomography and magnetic resonance imaging of an intraluminal arterial cast that was obtained from the same animal at sacrifice. Results show that resolution of the imaging modality strongly influences the level of detail, such as small side branches, in the final reconstruction. We developed an average morphology model for elastase-induced aneurysms in rabbits including the surrounding vasculature and describe a method for rapid prototyping of vascular models from the three-dimensional morphology. Our replicas can be manufactured in a short period of time and the final product is optically clear. In addition, the elasticity of the models can be controlled to represent arterial elasticity, which makes them ideal for optical investigations of detailed flow dynamics using measurement tools such as particle image velocimetry.

  16. Optomechanically induced transparency in multi-cavity optomechanical system with and without one two-level atom

    PubMed Central

    Sohail, Amjad; Zhang, Yang; Zhang, Jun; Yu, Chang-shui

    2016-01-01

    We analytically study the optomechanically induced transparency (OMIT) in the N-cavity system with the Nth cavity driven by pump, probing laser fields and the 1st cavity coupled to mechanical oscillator. We also consider that one atom could be trapped in the ith cavity. Instead of only illustrating the OMIT in such a system, we are interested in how the number of OMIT windows is influenced by the cavities and the atom and what roles the atom could play in different cavities. In the resolved sideband regime, we find that, the number of cavities precisely determines the maximal number of OMIT windows. It is interesting that, when the two-level atom is trapped in the even-labeled cavity, the central absorptive peak (odd N) or dip (even N) is split and forms an extra OMIT window, but if the atom is trapped in the odd-labeled cavity, the central absorptive peak (odd N) or dip (even N) is only broadened and thus changes the width of the OMIT windows rather than induces an extra window. PMID:27349325

  17. Experimental demonstration of acoustic wave induced magnetization switching in dipole coupled magnetostrictive nanomagnets for ultralow power computing

    NASA Astrophysics Data System (ADS)

    Sampath, Vimal; D'Souza, Noel; Atkinson, Gary M.; Bandyopadhyay, Supriyo; Atulasimha, Jayasimha

    2016-09-01

    Dipole-coupled cobalt nanomagnet pairs of elliptical shape (with their major axes parallel) are delineated on 128° Y-cut lithium niobate. Each pair is initially magnetized along the major axis with a magnetic field forming the (↑↑) state. When an acoustic wave (AW) is launched in the substrate from interdigitated electrodes, the softer nanomagnet in the pair flips to produce the (↑↓) state since the AW modulates the stress anisotropy. This executes the logical NOT operation because the output bit encoded in the magnetization state of the softer nanomagnet becomes the logic complement of the input bit encoded in the magnetization of the harder one. The AW acts as a clock to trigger the NOT operation and the energy dissipated is a few tens of aJ. Such AW clocking can be utilized to flip nanomagnets in a chain sequentially to steer logic bits unidirectionally along a nanomagnetic logic wire with miniscule energy dissipation.

  18. Vapor-liquid equilibrium and polarization behavior of the GCP water model: Gaussian charge-on-spring versus dipole self-consistent field approaches to induced polarization.

    PubMed

    Chialvo, Ariel A; Moucka, Filip; Vlcek, Lukas; Nezbeda, Ivo

    2015-04-16

    We developed the Gaussian charge-on-spring (GCOS) version of the original self-consistent field implementation of the Gaussian Charge Polarizable water model and test its accuracy to represent the polarization behavior of the original model involving smeared charges and induced dipole moments. For that purpose we adapted the recently proposed multiple-particle-move (MPM) within the Gibbs and isochoric-isothermal ensembles Monte Carlo methods for the efficient simulation of polarizable fluids. We assessed the accuracy of the GCOS representation by a direct comparison of the resulting vapor-liquid phase envelope, microstructure, and relevant microscopic descriptors of water polarization along the orthobaric curve against the corresponding quantities from the actual GCP water model.

  19. The CO-Ne van der Waals complex: ab initio intermolecular potential energy, interaction induced electric dipole moment and polarizability surfaces, and second virial coefficients.

    PubMed

    Baranowska, Angelika; Fernández, Berta; Rizzo, Antonio; Jansík, Branislav

    2009-11-14

    The intermolecular potential energy, interaction induced electric dipole moment and polarizability surfaces of the CO-Ne van der Waals complex are calculated using coupled cluster methods and the d-aug-cc-pVTZ basis set extended with a set of 3s3p2d1f1g midbond functions placed in the middle of the van der Waals bond. After fitting the interaction properties to appropriate analytical functions the surfaces are further used in semiclassical calculations of the pressure, the dielectric and the refractivity second virial coefficients of the system. The interaction potential energy surface has a single minimum (-49.9952 cm(-1)), which corresponds to R = 3.383 A and theta = 79.4 degrees. The computed dielectric second virial coefficient B(epsilon) approximately -0.27 cm(6) mol(-2) around the room temperature.

  20. Dark matter, muon g -2 , electric dipole moments, and Z →ℓi+ℓj- in a one-loop induced neutrino model

    NASA Astrophysics Data System (ADS)

    Chiang, Cheng-Wei; Okada, Hiroshi; Senaha, Eibun

    2017-07-01

    We study a simple one-loop induced neutrino mass model that contains both bosonic and fermionic dark matter candidates and has the capacity to explain the muon anomalous magnetic moment anomaly. We perform a comprehensive analysis by taking into account the relevant constraints of charged lepton flavor violation, electric dipole moments, and neutrino oscillation data. We examine the constraints from lepton flavor-changing Z boson decays at the one-loop level, particularly when the involved couplings contribute to the muon g -2 . It is found that BR (Z →μ τ )≃(10-7- 10-6) while BR (τ →μ γ )≲10-11 in the fermionic dark matter scenario. The former can be probed by the precision measurement of the Z boson at future lepton colliders.

  1. Vapor–Liquid Equilibrium and Polarization Behavior of the GCP Water Model: Gaussian Charge-on-Spring versus Dipole Self-Consistent Field Approaches to Induced Polarization

    DOE PAGES

    Chialvo, Ariel A.; Moucka, Filip; Vlcek, Lukas; ...

    2015-03-24

    Here we implemented the Gaussian charge-on-spring (GCOS) version of the original self-consistent field implementation of the Gaussian Charge Polarizable water model and test its accuracy to represent the polarization behavior of the original model involving smeared charges and induced dipole moments. Moreover, for that purpose we adapted the recently developed multiple-particle-move (MPM) within the Gibbs and isochoric-isothermal ensembles Monte Carlo methods for the efficient simulation of polarizable fluids. We also assessed the accuracy of the GCOS representation by a direct comparison of the resulting vapor-liquid phase envelope, microstructure, and relevant microscopic descriptors of water polarization along the orthobaric curve againstmore » the corresponding quantities from the actual GCP water model.« less

  2. Vapor–Liquid Equilibrium and Polarization Behavior of the GCP Water Model: Gaussian Charge-on-Spring versus Dipole Self-Consistent Field Approaches to Induced Polarization

    SciTech Connect

    Chialvo, Ariel A.; Moucka, Filip; Vlcek, Lukas; Nezbeda, Ivo

    2015-03-24

    Here we implemented the Gaussian charge-on-spring (GCOS) version of the original self-consistent field implementation of the Gaussian Charge Polarizable water model and test its accuracy to represent the polarization behavior of the original model involving smeared charges and induced dipole moments. Moreover, for that purpose we adapted the recently developed multiple-particle-move (MPM) within the Gibbs and isochoric-isothermal ensembles Monte Carlo methods for the efficient simulation of polarizable fluids. We also assessed the accuracy of the GCOS representation by a direct comparison of the resulting vapor-liquid phase envelope, microstructure, and relevant microscopic descriptors of water polarization along the orthobaric curve against the corresponding quantities from the actual GCP water model.

  3. Ferrofluid Photonic Dipole Contours

    NASA Astrophysics Data System (ADS)

    Snyder, Michael; Frederick, Jonathan

    2008-03-01

    Understanding magnetic fields is important to facilitate magnetic applications in diverse fields in industry, commerce, and space exploration to name a few. Large electromagnets can move heavy loads of metal. Magnetic materials attached to credit cards allow for fast, accurate business transactions. And the Earth's magnetic field gives us the colorful auroras observed near the north and south poles. Magnetic fields are not visible, and therefore often hard to understand or characterize. This investigation describes and demonstrates a novel technique for the visualization of magnetic fields. Two ferrofluid Hele-Shaw cells have been constructed to facilitate the imaging of magnetic field lines [1,2,3,4]. We deduce that magnetically induced photonic band gap arrays similar to electrostatic liquid crystal operation are responsible for the photographed images and seek to mathematically prove the images are of exact dipole nature. We also note by comparison that our photographs are very similar to solar magnetic Heliosphere photographs.

  4. All-dielectric metasurface analogue of electromagnetically induced transparency [High Quality Factor Fano-Resonant All-Dielectric Metamaterials

    SciTech Connect

    Yang, Yuanmu; Kravchenko, Ivan I.; Briggs, Dayrl P.; Valentine, Jason

    2014-12-16

    Fano-resonant plasmonic metamaterials and nanostructures have become a major focus of the nanophotonics fields over the past several years due their ability to produce high quality factor (Q-factor) resonances. The origin of such resonances is the interference between a broad and narrow resonance, ultimately allowing suppression of radiative damping. However, Fano-resonant plasmonic structures still suffer non-radiative damping due to Ohmic loss, ultimately limiting the achievable Q-factors to values less than ~10. Here, we report experimental demonstration of Fano-resonant silicon-based metamaterials that have a response that mimics the electromagnetically induced transparency (EIT) found in atomic systems. Due to extremely low absorption loss, a record-high quality factor (Q-factor) of 306 was experimentally observed. Furthermore, the unit cell of the metamaterial was designed with a feed-gap which results in strong local field enhancement in the surrounding medium resulting in strong light-matter interaction. This allows the metamaterial to serve as a refractive index sensor with a figure-of-merit (FOM) of 101, far exceeding the performance of previously demonstrated localized surface plasmon resonance sensors.

  5. All-dielectric metasurface analogue of electromagnetically induced transparency [High Quality Factor Fano-Resonant All-Dielectric Metamaterials

    DOE PAGES

    Yang, Yuanmu; Kravchenko, Ivan I.; Briggs, Dayrl P.; ...

    2014-12-16

    Fano-resonant plasmonic metamaterials and nanostructures have become a major focus of the nanophotonics fields over the past several years due their ability to produce high quality factor (Q-factor) resonances. The origin of such resonances is the interference between a broad and narrow resonance, ultimately allowing suppression of radiative damping. However, Fano-resonant plasmonic structures still suffer non-radiative damping due to Ohmic loss, ultimately limiting the achievable Q-factors to values less than ~10. Here, we report experimental demonstration of Fano-resonant silicon-based metamaterials that have a response that mimics the electromagnetically induced transparency (EIT) found in atomic systems. Due to extremely low absorptionmore » loss, a record-high quality factor (Q-factor) of 306 was experimentally observed. Furthermore, the unit cell of the metamaterial was designed with a feed-gap which results in strong local field enhancement in the surrounding medium resulting in strong light-matter interaction. This allows the metamaterial to serve as a refractive index sensor with a figure-of-merit (FOM) of 101, far exceeding the performance of previously demonstrated localized surface plasmon resonance sensors.« less

  6. Mixture of Electromagnetically Induced Transparency and Autler–Townes Splitting in a Five-Level Atomic System

    NASA Astrophysics Data System (ADS)

    Zhang, Xiao-Yun; Wu, Shan; Li, Hai-Chao

    2017-02-01

    Discerning electromagnetically induced transparency (EIT) from Autler–Townes splitting (ATS) is a significant issue in quantum optics and has attracted wide attention in various three-level configurations. Here we present a detailed study of EIT and ATS in a five-level atomic system considered to be composed of a four-level Y-type subsystem and a three-level Λ-type subsystem. In our theoretical calculations with standard density matrix formalism and steady-state approximation, we obtain the general analytical expression of the first-order matrix element responsible for the probe-field absorption. In light of the well-known three-level EIT and ATS criteria, we numerically show an intersection of EIT with ATS for the Y-type subsystem. Furthermore, we show that an EIT dip is sandwiched between two ATS dips (i.e., multi-dip mixture of EIT and ATS) in the absorption line for the five-level system, which can be explained by the dressed-state theory and Fano interference. Supported by the National Natural Science Foundation of China under Grant Nos. 11274132, 11547208, and the Science Foundation of China Three Gorges University

  7. Reversible Fano resonance by transition from fast light to slow light in a coupled-resonator-induced transparency structure.

    PubMed

    Zhang, Yundong; Zhang, Xuenan; Wang, Ying; Zhu, Ruidong; Gai, Yulong; Liu, Xiaoqi; Yuan, Ping

    2013-04-08

    We theoretically propose and experimentally perform a novel dispersion tuning scheme to realize a tunable Fano resonance in a coupled-resonator-induced transparency (CRIT) structure coupled Mach-Zehnder interferometer. We reveal that the profile of the Fano resonance in the resonator coupled Mach-Zehnder interferometers (RCMZI) is determined not only by the phase shift difference between the two arms of the RCMZI but also by the dispersion (group delay) of the CRIT structure. Furthermore, it is theoretically predicted and experimentally demonstrated that the slope and the asymmetry parameter (q) describing the Fano resonance spectral line shape of the RCMZI experience a sign reversal when the dispersion of the CRIT structure is tuned from abnormal dispersion (fast light) to normal dispersion (slow light). These theoretical and experimental results indicate that the reversible Fano resonance which holds significant implications for some attractive device applications such as highly sensitive biochemical sensors, ultrafast optical switches and routers can be realized by the dispersion tuning scheme in the RCMZI.

  8. Electromagnetically induced transparency: the thickness of the vapor column is of the order of a light wavelength

    SciTech Connect

    Pashayan-Leroy, Y.; Leroy, C.; Sargsyan, A.; Papoyan, A.; Sarkisyan, D.

    2007-08-15

    Electromagnetically induced transparency (EIT) effect has been studied using an extremely thin cell (ETC) with the thickness of an Rb vapor column of the order of light wavelength {lambda} (780 nm) and varying in the range of 0.5{lambda}-2.5{lambda}. {lambda}-systems on the D{sub 2} line of {sup 85}Rb and {sup 87}Rb have been studied experimentally. Along with EIT resonance, we study the peculiarities of velocity-selective optical pumping/saturation (VSOP) resonances, which accompany the EIT resonance and, as a rule, are spectrally broader. It is demonstrated that size-conditioned strongly anisotropic contribution of atoms with different velocities in an ETC causes several dramatic differences of the EIT and VSOP resonances formation in the ETC as compared with an ordinary 1-10 cm long cell. Particularly, in the case of the ETC, the EIT linewidth and contrast dramatically depend on the coupling laser detuning from the exact atomic transition. A theoretical model taking into account the peculiarities of transmission spectra when L=n{lambda} and L=(2n+1){lambda}/2 (n is an integer) has been developed. The experimental transmission spectra are well described by the theoretical model developed. The possibility of EIT resonance formation when atomic column thickness is of the order of L=0.5{lambda} and less is theoretically predicted.

  9. Generation of atom-photon entangled states in atomic Bose-Einstein condensate via electromagnetically induced transparency

    SciTech Connect

    Kuang Leman; Zhou Lan

    2003-10-01

    In this paper, we present a method to generate continuous-variable-type entangled states between photons and atoms in atomic Bose-Einstein condensate (BEC). The proposed method involves an atomic BEC with three internal states, a weak quantized probe laser, and a strong classical coupling laser, which form a three-level {lambda}-shaped BEC system. We consider a situation where the BEC is in electromagnetically induced transparency with the coupling laser being much stronger than the probe laser. In this case, the upper and intermediate levels are unpopulated, so that their adiabatic elimination enables an effective two-mode model involving only the atomic field at the lowest internal level and the quantized probe laser field. Atom-photon quantum entanglement is created through laser-atom and interatomic interactions, and two-photon detuning. We show how to generate atom-photon entangled coherent states and entangled states between photon (atom) coherent states and atom-(photon-) macroscopic quantum superposition (MQS) states, and between photon-MQS and atom-MQS states.

  10. Realization of two-dimensional Aubry-André localization of light waves via electromagnetically induced transparency

    NASA Astrophysics Data System (ADS)

    Li, Hui-jun; Dou, Jian-peng; Huang, Guoxiang

    2014-03-01

    We propose a scheme to construct a two-dimensional Aubry-André (AA) model and realize two-dimensional AA localization of light waves via electromagnetically induced transparency (EIT). The system we suggest is a cold, resonant atomic gas with an N-type level configuration and interacting with probe, control, assisted, and far-detuned laser fields. We show that under EIT conditions the probe-field envelope obeys a modified nonlinear Schrödinger equation with a quasiperiodic potential, which becomes a two-dimensional nonlinear AA model when the system parameters are suitably chosen. The quasiperiodic potential is obtained by the cross-phase modulation of the assisted field and the Stark shift of the far-detuned laser field. In addition, the cubic nonlinearity term appearing in the model is contributed by the self-phase modulation of the probe field. We demonstrate that the system can be used to not only realize various two-dimensional AA localizations of light waves, but also to display nonlinearity and dimensionality effects on the AA localizations.

  11. Transient development of Zeeman electromagnetically induced transparency during propagation of Raman-Ramsey pulses through Rb buffer gas cell

    NASA Astrophysics Data System (ADS)

    Nikolić, S. N.; Radonjić, M.; Lučić, N. M.; Krmpot, A. J.; Jelenković, B. M.

    2015-02-01

    We investigate, experimentally and theoretically, time development of Zeeman electromagnetically induced transparency (EIT) during propagation of two time separated polarization laser pulses, preparatory and probe, through Rb vapour. The pulses were produced by modifying laser intensity and degree of elliptical polarization. The frequency of the single laser beam is locked to the hyperfine {{F}g}=2\\to {{F}e}=1 transition of the D1 line in 87Rb. Transients in the intensity of {{σ }-} component of the transmitted light are measured or calculated at different values of the external magnetic field, during both preparatory and probe pulse. Zeeman EIT resonances at particular time instants of the pulse propagation are reconstructed by appropriate sampling of the transients. We observe how laser intensity, Ramsey sequence and the Rb cell temperature affect the time dependence of EIT line shapes, amplitudes and linewidths. We show that at early times of the probe pulse propagation, several Ramsey fringes are present in EIT resonances, while at later moments a single narrow peak prevails. Time development of EIT amplitudes are determined by the transmitted intensity of the {{σ }-} component during the pulse propagation.

  12. Plasmon induced transparency and absorption in bright-bright mode coupling metamaterials: a radiating two-oscillator model analysis

    NASA Astrophysics Data System (ADS)

    Hu, Xinguang; Yuan, Shuai; Armghan, Ammar; Liu, Yang; Jiao, Zheng; Lv, Haijiang; Zeng, Cheng; Huang, Ying; Huang, Qingzhong; Wang, Yi; Xia, Jinsong

    2017-01-01

    A radiating two-oscillator model is developed to describe plasmon-induced transparency (PIT) and absorption (PIA) spectral responses in a two-bright mode coupling system, from which the analytical expressions of the scattering parameters are derived. To verify the validity of the model, the scattering parameters are used to fit with corresponding numerical data obtained from finite difference time domain simulations by using a simple planar structure. The transmission and reflection spectra can be well reproduced simultaneously, indicating that the model is effective and convenient for describing two-bright mode coupling. By analyzing the transmission phase of the bright modes, the physical regime behind the PIT effect is revealed. Successful reproduction of group delay shows that the model can be used in analyzing slow light effects. In addition, a study on resonance detuning and the damping factor indicates that the two parameters should be considered simultaneously in the PIT effect. PIA-like phenomenon can also be achieved in the system but with a smaller detuning compared with the PIT effect. The results obtained here may be useful for designing active devices in the future.

  13. Dipole plasmon resonance induced large third-order optical nonlinearity of Au triangular nanoprism in infrared region.

    PubMed

    Chen, Ziyu; Dai, Hongwei; Liu, Jiaming; Xu, Hui; Li, Zixuan; Zhou, Zhang-Kai; Han, Jun-Bo

    2013-07-29

    Au triangular nanoprisms with strong dipole plasmon absorption peak at 1240 nm were prepared by wet chemical methods. Both numerical calculations and experiments were carried out to investigate the optical properties of the samples. Finite difference time domain (FDTD) and Local Density of States (LDOS) calculations demonstrate that strong electric field enhancement and large LDOS can be obtained at tip areas of the Au triangular nanoprisms. Z scan techniques were used to characterize the nonlinear absorption, nonlinear refraction, as well as one- and two-photon figures of merit (W and T, respectively) of the sample. The results show that maximum nonlinear refractive index can be obtained around the resonance absorption wavelength of 1240 nm, detuning the wavelength from the absorption peak will lead to the decrease of the nonlinear refractive index n(2), while the nonlinear absorption coefficient β doesn't change much with the wavelength. This large wavelength dependence of n(2) and small change of β enable the sample to satisfy the all-optical switching demand of W> 1 and T< 1 easily in a large wavelength range of 1200-1300 nm. These significant nonlinear properties of the sample imply that Au triangular nanoprism is a good candidate for future optical switches in infrared optical communication wavelength region.

  14. Isomeric ratios in photonuclear reactions of molybdenum isotopes induced by bremsstrahlung in the giant dipole resonance region

    NASA Astrophysics Data System (ADS)

    Thiep, Tran Duc; An, Truong Thi; Cuong, Phan Viet; Vinh, Nguyen The; Hue, Bui Minh; Belov, A. G.; Maslov, O. D.; Mishinsky, G. V.; Zhemenik, V. I.

    2017-01-01

    We have determined the isomeric ratios of isomeric pairs 97m,gNb, 95m,gNb and 91m,gMo produced in 98Mo(γ, p)97m,gNb, 96Mo(γ, p)95m,gNb and 92Mo(γ, n)91m,gMo photonuclear reactions in the giant dipole resonance (GDR) region by the activation method. The results were analyzed, discussed and compared with the similar data from literature to examine the role of excitation energy, neutron configuration, channel effect and direct and pre-equilibrium processes in (γ, p) photonuclear reactions. In this work the isomeric ratios for 97m,gNb from 14 to 19 MeV, for 195m,gNb from14 to 24 MeV except 20 and 23.5 MeV and for 91m,gMo at 14 and 15 MeV are the first time measurements.

  15. Results from heater-induced quenches of A 4. 5 m Reference Design D dipole for the SSC

    SciTech Connect

    Ganetis, G.; Prodell, A.

    1986-01-01

    Quench studies were performed using a 4.5 m long Reference Design D, SSC dipole to determine the temperature rise of the magnet conductor during a quench by measuring the resistance of the conductor cable in the immediate vicinity of the quench. The single bore magnet was wound with improved NbTi conductor in a 2-layer cosine theta coil configuration of 4.0 cm inner diameter. Eight pairs of voltage taps were installed at various locations on the right side of the inner coil of the magnet. ''Spot'' heaters were centrally located between the voltage taps of 4 of these pairs on the midplane turn of the inner coil to initiate magnet quenches. A redundant array of voltage taps and heaters was also installed on the left side of the inner coil. The resistance of the conductor was obtained from observations of the current and voltage during a magnet quench. The temperature of the conductor was then determined by comparing its resistance to an R vs T curve appropriate for the conductor. The quantity ..integral.. I/sup 2/dt and the temperature, T, are presented as a function of current, and the maximum conductor temperature is shown as a function of ..integral.. I/sup 2/dt. Measured longitudinal and azimuthal quench propagation velocities are also presented as a function of magnet current, and the temperatures at several locations on the inner magnet coil are plotted as a function of the time after a quench was initiated.

  16. Damp-Heat Induced Degradation of Transparent Conducting Oxides for Thin-Film Solar Cells: Preprint

    SciTech Connect

    Pern, F. J.; Noufi, R.; Li, X.; DeHart, C.; To, B.

    2008-05-01

    The stability of intrinsic and Al-doped single- and bi-layer ZnO for thin-film CuInGaSe2 solar cells, along with Al-doped Zn1-xMgxO alloy and Sn-doped In2O3 (ITO) and F-doped SnO2, was evaluated by direct exposure to damp heat (DH) at 85oC and 85% relative humidity. The results show that the DH-induced degradation rates followed the order of Al-doped ZnO and Zn1-xMgxO >> ITO > F:SnO2. The degradation rates of Al:ZnO were slower for films of higher thickness, higher substrate temperature in sputter-deposition, and with dry-out intervals. As inferred from the optical micro-imaging showing the initiation and propagation of degrading patterns and regions, the degradation behavior appears similar for all TCOs, despite the obvious difference in the degradation rate. A degradation mechanism is proposed to explain the temporal process involving thermal hydrolysis.

  17. Color transparency

    SciTech Connect

    Jennings, B.K.; Miller, G.A.

    1993-11-01

    The anomously large transmission of nucleons through a nucleus following a hard collision is explored. This effect, known as color transparency, is believed to be a prediction of QCD. The necessary conditions for its occurrence and the effects that must be included a realistic calculation are discussed.

  18. The effect of impurities on linear and nonlinear absorption coefficient and refractive index of the spherical quantum dot four-level M-model the phenomenon of electromagnetically induced transparency

    NASA Astrophysics Data System (ADS)

    Damiri, H.; Askari, H. R.

    2017-01-01

    In this paper, the effect of impurities on the phenomenon of electromagnetically induced transparency in a spherical quantum dot with parabolic potential is examined. It is assumed that spherical quantum dot has configuration four levels model M. First, consider the polarization Z for light; rotating wave approximation approach, rotating coordinate system, as well as the density matrix approach, we examine the phenomenon of electromagnetically induced transparency in spherical quantum dot. Finally, with regard to impurities of the disorder, we review electromagnetically induced transparency and Changes resulting from the presence of impurities.

  19. Coherent phenomena in terahertz 2D plasmonic structures: strong coupling, plasmonic crystals, and induced transparency by coupling of localized modes

    NASA Astrophysics Data System (ADS)

    Dyer, Gregory C.; Aizin, Gregory R.; Allen, S. James; Grine, Albert D.; Bethke, Don; Reno, John L.; Shaner, Eric A.

    2014-05-01

    The device applications of plasmonic systems such as graphene and two dimensional electron gases (2DEGs) in III-V heterostructures include terahertz detectors, mixers, oscillators and modulators. These two dimensional (2D) plasmonic systems are not only well-suited for device integration, but also enable the broad tunability of underdamped plasma excitations via an applied electric field. We present demonstrations of the coherent coupling of multiple voltage tuned GaAs/AlGaAs 2D plasmonic resonators under terahertz irradiation. By utilizing a plasmonic homodyne mixing mechanism to downconvert the near field of plasma waves to a DC signal, we directly detect the spectrum of coupled plasmonic micro-resonator structures at cryogenic temperatures. The 2DEG in the studied devices can be interpreted as a plasmonic waveguide where multiple gate terminals control the 2DEG kinetic inductance. When the gate tuning of the 2DEG is spatially periodic, a one-dimensional finite plasmonic crystal forms. This results in a subwavelength structure, much like a metamaterial element, that nonetheless Bragg scatters plasma waves from a repeated crystal unit cell. A 50% in situ tuning of the plasmonic crystal band edges is observed. By introducing gate-controlled defects or simply terminating the lattice, localized states arise in the plasmonic crystal. Inherent asymmetries at the finite crystal boundaries produce an induced transparency-like phenomenon due to the coupling of defect modes and crystal surface states known as Tamm states. The demonstrated active control of coupled plasmonic resonators opens previously unexplored avenues for sensitive direct and heterodyne THz detection, planar metamaterials, and slow-light devices.

  20. Ion induced dipole clusters H(n)- (3 ≤ n-odd ≤ 13): density functional theory calculations of structure and energy.

    PubMed

    Huang, Lulu; Matta, Chérif F; Massa, Lou

    2011-11-17

    We investigate anew the possible equilibrium geometries of ion induced dipole clusters of hydrogen molecular ions, of molecular formula H(n)(-) (3 ≤ n-odd ≤ 13). Our previous publications [Sapse, A. M.; et al. Nature 1979, 278, 332; Rayez, J. C.; et al., J. Chem. Phys. 1981, 75, 5393] indicated these molecules would have a shallow minimum and adopt symmetrical geometries that accord with the valence shell electron pair repulsion (VSEPR) rules for geometries defined by electron pairs surrounding a central point of attraction. These earlier calculations were all based upon Hartree-Fock (HF) calculations with a fairly small basis of atomic functions, except for the H3(-) ion for which configuration interaction (CI) calculations were carried out. A related paper [Hirao, K.; et al., Chem. Phys. 1983, 80, 237] carried out similar calculations on the same clusters, finding geometries similar to our earlier calculations. However, although that paper argued that the stabilization energy of negative ion clusters H(n)(-) is small, vibration frequencies for the whole set of clusters was not reported, and so a definitive assertion of a true equilibrium was not present. In this paper we recalculate the energetics of the ion induced dipole clusters using density function theory (DFT) B3LYP method calculations in a basis of functions (6-311++G(d,p)). By calculating the vibration frequencies of the VSEPR geometries, we prove that in general they are not true minima because not all the resulting frequencies correspond to real values. By searching the energy surface of the B3LYP calculations, we find the true minimum geometries, which are surprising configurations and are perhaps counterintuitive. We calculate the total energy and binding energy of the new geometries. We also calculate the bond paths associated with the quantum theory of atoms in molecules (QTAIM). The B3LYP/6-311++G(d,p) results, for each molecule, deliver bond paths that radiate between each polarized H2

  1. Self-induced transparency scenario revisited via beat-wave heating induced by Doppler shift in overdense plasma layer

    SciTech Connect

    Ghizzo, A.; Del Sarto, D.; Reveille, T.; Besse, N.; Klein, R.

    2007-06-15

    Maxwell-fluid simulations on a flat-topped moderately overdense plasma slab (typically n{sub 0}/n{sub c}=1-2) by Berezhiani et al. [Phys. Plasmas 66, 062308 (2005)] (see also the previous work of Tushentsov et al. [Phys. Rev. Lett. 87, 275002 (2001)]) were seen to lead to dynamic penetration of an ultrahigh intensity laser pulse into an overdense plasma. Two qualitatively different scenarios for the penetration of laser pulse into the overdense plasma were presented depending on the background density. In the first one, the penetration of laser energy occurs by soliton-like structures moving into the plasma. In the last one, electron cavitation occurs and the penetration is possible over a finite length only. A kinetic extension is made in this paper using Vlasov-Maxwell simulations. Vlasov simulations revealed a rich variety of new phenomena associated with the trapped particle dynamics, which cannot be described in fluid models. Most notably is the observation, during the penetration phase of the pump electromagnetic wave, of a beat-wave heating scenario induced by the Doppler shift on the reflected wave at the (moving) wave front. This beat-wave generates low-frequency acoustic-like electron modes characterized by coherent trapping-type structures in phase space leading to an efficient (nonstochastic) heating process.

  2. Changes in earth's dipole.

    PubMed

    Olson, Peter; Amit, Hagay

    2006-11-01

    The dipole moment of Earth's magnetic field has decreased by nearly 9% over the past 150 years and by about 30% over the past 2,000 years according to archeomagnetic measurements. Here, we explore the causes and the implications of this rapid change. Maps of the geomagnetic field on the core-mantle boundary derived from ground-based and satellite measurements reveal that most of the present episode of dipole moment decrease originates in the southern hemisphere. Weakening and equatorward advection of normal polarity magnetic field by the core flow, combined with proliferation and growth of regions where the magnetic polarity is reversed, are reducing the dipole moment on the core-mantle boundary. Growth of these reversed flux regions has occurred over the past century or longer and is associated with the expansion of the South Atlantic Anomaly, a low-intensity region in the geomagnetic field that presents a radiation hazard at satellite altitudes. We address the speculation that the present episode of dipole moment decrease is a precursor to the next geomagnetic polarity reversal. The paleomagnetic record contains a broad spectrum of dipole moment fluctuations with polarity reversals typically occurring during dipole moment lows. However, the dipole moment is stronger today than its long time average, indicating that polarity reversal is not likely unless the current episode of moment decrease continues for a thousand years or more.

  3. Phenomenological Transparency.

    PubMed

    McGuire, Morgan; Mara, Michael

    2017-01-20

    Translucent objects such as fog, clouds, smoke, glass, ice, and liquids are pervasive in cinematic environments because they frame scenes in depth and create visually-compelling shots. Unfortunately, they are hard to render in real-time and have thus previously been rendered poorly compared to opaque surfaces. This paper introduces the first model for a real-time rasterization algorithm that can simultaneously approximate the following transparency phenomena: wavelength-varying ("colored") transmission, translucent colored shadows, caustics, volumetric light and shadowing, partial coverage, diffusion, and refraction. All render efficiently with order-independent draw calls and low bandwidth. We include source code.

  4. Measurement of magic-wavelength optical dipole trap by using the laser-induced fluorescence spectra of trapped single cesium atoms.

    PubMed

    Liu, Bei; Jin, Gang; Sun, Rui; He, Jun; Wang, Junmin

    2017-07-10

    Based on the multi-level model, we have calculated light shifts for Zeeman states of hyperfine levels of cesium (Cs) 6S1/2 ground state and 6P3/2 excited state. The magic-wavelength linearly-polarized optical dipole trap (ODT) for Cs 6S1/2 |F = 4, mF = + 4ñ - 6P3/2 |F(') = 5, mF = + 5ñ transition is experimentally constructed and characterized by using the laser-induced fluorescence spectra of trapped single Cs atoms. The magic wavelength is 937.7 nm which produces almost the same light shift for 6S1/2 |F = 4, mF = + 4ñ ground state and 6P3/2 |F(') = 5, mF = + 5ñ excited state with linearly-polarized ODT laser beam. Compared to undisturbed Cs 6S1/2 |F = 4, mF = + 4ñ - 6P3/2 |F(') = 5, mF = + 5ñ transition frequency in free space, the differential light shift is less than 0.7 MHz in a linearly-polarized 937.7 nm ODT, which is less than 1.2% of the trap depth. We also discussed influence of the trap depth and the bias magnetic field on the measurement results.

  5. Measurement of magic-wavelength optical dipole trap by using the laser-induced fluorescence spectra of trapped single cesium atoms

    NASA Astrophysics Data System (ADS)

    Liu, Bei; Jin, Gang; Sun, Rui; He, Jun; Wang, Junmin

    2017-07-01

    Based on the multi-level model, we have calculated light shifts for Zeeman states of hyperfine levels of cesium (Cs) 6S1/2 ground state and 6P3/2 excited state.The magic-wavelength linearly-polarized optical dipole trap (ODT) for Cs 6S1/2 F=4, mF=+4 - 6P3/2 F'=5, mF=+5 transition is experimentally constructed and characterized by using the laser-induced fluorescence spectra of trapped single Cs atoms. The magic wavelength is 937.7 nm which produces almost the same light shift for 6S1/2 F=4, mF=+4 ground state and 6P3/2 F'=5, mF=+5 excited state with linearly-polarized ODT laser beam. Compared to undisturbed Cs 6S1/2 F=4, mF=+4 - 6P3/2 F'=5, mF=+5 transition frequency in free space, the differential light shift is less than 0.7 MHz in a linearly-polarized 937.7 nm ODT, which is less than 1.2% of the trap depth. We also discussed influence of the trap depth and the bias magnetic field on the measurement results.

  6. Black perception in a transparent OLED display.

    PubMed

    Kim, Hyosun; Seo, Young-Jun; Yang, Byungchoon; Chu, Hye Yong

    2017-02-20

    Black perception (perceived blackness of gray 0) of transparent OLED displays was studied in this paper. In pre-test, maximum luminances of acceptable black level under various surround conditions were found in a non-transparent display. In the first experiment, the luminance of a transparent patch was compared with that of an opaque one in order to find the effect of transparency on black perception. As a result, participants perceived the transparent patch darker than the opaque one even when the two were in similar luminance levels, which we termed as the "Transparency Effect." In the second experiment, the perceived brightness of gray 0 with various background brightness conditions was investigated to observe the effect of induced black perception. Most participants perceived the luminance of gray 0 darker with brighter background luminance, but some did not. It might result from transparency of gray 0 which had a role as a window presenting the area overlapped with a transparent OLED display.

  7. Hydrogen bonding and induced dipole moments in water: predictions from the Gaussian charge polarizable model and Car-Parrinello molecular dynamics.

    PubMed

    Dyer, Peter J; Cummings, Peter T

    2006-10-14

    We compare a new classical water model, which features Gaussian charges and polarizability (GCPM) with ab initio Car-Parrinello molecular dynamics (CPMD) simulations. We compare the total dipole moment, the total dipole moment distribution, and degree of hydrogen bonding at ambient to supercritical conditions. We also compared the total dipole moment calculated from both the electron density (partitioning the electron density among molecules based on a zero electron flux condition), and from the center of localized Wannier function centers (WFCs). Compared to CPMD, we found that GCPM overpredicts the dipole moment derived by partitioning the electron density and underpredicts that obtained from the WFCs, but exhibits similar trends and distribution of values. We also found that GCPM predicted similar degrees of hydrogen bonding compared to CPMD and has a similar structure.

  8. Novel Fragmentation Pathways of Anionic Adducts of Steroids Formed by Electrospray Anion Attachment Involving Regioselective Attachment, Regiospecific Decompositions, Charge-Induced Pathways, and Ion-Dipole Complex Intermediates

    NASA Astrophysics Data System (ADS)

    Rannulu, Nalaka S.; Cole, Richard B.

    2012-09-01

    The analysis of several bifunctional neutral steroids, 5-α-pregnane diol (5-α-pregnane-3α-20βdiol), estradiol (3,17α-dihydroxy-1,3,5(10)-estratriene), progesterone (4-pregnene-3,20-dione), lupeol (3β-hydroxy-20(29)-lupene), pregnenolone (5-pregnen-3β-ol-20-one), and pregnenolone acetate (5-pregnen-3β-ol-20-one acetate) was accomplished by negative ion electrospray mass spectrometry (ESI-MS) employing adduct formation with various anions: fluoride, bicarbonate, acetate, and chloride. Fluoride yielded higher abundances of anionic adducts and more substantial abundances of deprotonated molecules compared with other investigated anions. Collision-induced dissociation (CID) of precursor [M + anion]- adducts of these steroids revealed that fluoride adduct [M + F]- precursors first lose HF to produce [M - H]- and then undergo consecutive decompositions to yield higher abundances of structurally-informative product ions than the other tested anions. In addition to charge-remote fragmentations, the majority of CID pathways of estradiol are deduced to occur via charge-induced fragmentation. Most interestingly, certain anions exhibit preferential attachment to a specific site on these bifunctional steroid molecules, which we are calling "regioselective anion attachment." Regioselective anion attachment is evidenced by subsequent regiospecific decomposition. Regioselective attachment of fluoride (and acetate) anions to low (and moderate) acidity functional groups of pregnenolone, respectively, is demonstrated using deuterated compounds. Moreover, the formation of unique intermediate ion-dipole complexes leading to novel fragmentation pathways of fluoride adducts of pregnenolone acetate, and bicarbonate adducts of d4-pregnenolone, are also discussed.

  9. Novel fragmentation pathways of anionic adducts of steroids formed by electrospray anion attachment involving regioselective attachment, regiospecific decompositions, charge-induced pathways, and ion-dipole complex intermediates.

    PubMed

    Rannulu, Nalaka S; Cole, Richard B

    2012-09-01

    The analysis of several bifunctional neutral steroids, 5-α-pregnane diol (5-α-pregnane-3α-20βdiol), estradiol (3,17α-dihydroxy-1,3,5(10)-estratriene), progesterone (4-pregnene-3,20-dione), lupeol (3β-hydroxy-20(29)-lupene), pregnenolone (5-pregnen-3β-ol-20-one), and pregnenolone acetate (5-pregnen-3β-ol-20-one acetate) was accomplished by negative ion electrospray mass spectrometry (ESI-MS) employing adduct formation with various anions: fluoride, bicarbonate, acetate, and chloride. Fluoride yielded higher abundances of anionic adducts and more substantial abundances of deprotonated molecules compared with other investigated anions. Collision-induced dissociation (CID) of precursor [M + anion](-) adducts of these steroids revealed that fluoride adduct [M + F](-) precursors first lose HF to produce [M - H](-) and then undergo consecutive decompositions to yield higher abundances of structurally-informative product ions than the other tested anions. In addition to charge-remote fragmentations, the majority of CID pathways of estradiol are deduced to occur via charge-induced fragmentation. Most interestingly, certain anions exhibit preferential attachment to a specific site on these bifunctional steroid molecules, which we are calling "regioselective anion attachment." Regioselective anion attachment is evidenced by subsequent regiospecific decomposition. Regioselective attachment of fluoride (and acetate) anions to low (and moderate) acidity functional groups of pregnenolone, respectively, is demonstrated using deuterated compounds. Moreover, the formation of unique intermediate ion-dipole complexes leading to novel fragmentation pathways of fluoride adducts of pregnenolone acetate, and bicarbonate adducts of d(4)-pregnenolone, are also discussed.

  10. Laboratory Dipole Plasma Physics

    NASA Astrophysics Data System (ADS)

    Kesner, Jay

    2011-10-01

    Modern laboratory studies of plasma confined by a strong dipole magnet originated twenty years ago when it was learned that planetary magnetospheres have centrally-peaked plasma pressure profiles that form naturally when solar wind drives plasma circulation and heating. Unlike other internal rings devices, like spherators and octupoles, the magnetic flux tubes of the dipole field expand rapidly with radius. Unlike plasma confinement devices that obtain stability from magnetic shear and average good curvature, like tokamaks and levitrons, the dipole-confined plasma obtains stability from plasma compressibility. These two geometric characteristics of the dipole field have profound consequences: (i) plasma can be stable with local beta exceeding unity, (ii) fluctuations can drive either heat or particles inward to create stationary profiles that are strongly peaked, and (iii) the confinement of particles and energy can decouple. During the past decade, several laboratory dipole experiments and modeling efforts have lead to new understanding of interchange, centrifugal and entropy modes, nonlinear gyrokinetics, and plasma transport. Two devices, the LDX experiment at MIT and RT-1 at the University of Tokyo, operate with levitated superconducting dipole magnets. With a levitated dipole, not only is very high-beta plasma confined in steady state but, also, levitation produces high-temperature at low input power and demonstrates that toroidal magnetic confinement of plasma does not require a toroidal field. Modeling has explained many of the processes operative in these experiments, including the observation of a strong inward particle pinch. Turbulent low-frequency fluctuations in dipole confined plasma cause adiabatic transport and form a fundamental linkage between the radial variation of flux-tube volume and the centrally peaked density and pressure profiles. In collaboration with M.E. Mauel and D.T. Garnier; supported by DoE FG02-98ER54458.

  11. Silicon-Induced UV Transparency in Phosphate Glasses and Its Application to the Enhancement of the UV Type B Emission of Gd(3).

    PubMed

    Jiménez, José A

    2017-05-10

    The silicon route to improve the ultraviolet (UV) transparency in phosphate glasses is investigated and further exploited to enhance the UV type B (280-320 nm) emission of gadolinium(III) relevant for biomedical applications. The glasses were synthesized with a barium phosphate composition by melt-quenching in ambient atmosphere and the optical properties investigated by optical absorption and photoluminescence (PL) spectroscopy including emission decay kinetics. An improvement in the UV transparency was gradually developed for the glasses melted merely with increasing amounts of Si powder. A particular PL in the visible was also exhibited for such glasses under excitation at 275 nm, consistent with the presence of Si-induced defects. For Si-Gd codoped glasses, the UV transparency was likewise manifested, while the UV emission from Gd(3+) around 312 nm was enhanced with the increase in Si concentration (up to ∼6.7 times). Moreover, along with the Gd(3+) PL intensity enhancement, a linear correlation was revealed between the increase in decay times for the Gd(3+6)P7/2-emitting state and the amount of silicon. It is then suggested that the improved PL properties of gadolinium(III) originate from the increased UV transparency of the host and the consequent precluding of a nonradiative energy transfer from Gd(3+) to the matrix. Accordingly, a role of Si as PL quenching inhibitor is supported. The demonstrated efficacy of the Si-Gd codoping concept realized by a facile glass synthesis procedure may appeal to the application of the UV-emitting glasses for phototherapy lamps.

  12. Electric field effect on the impurity-related electromagnetically induced transparency in a quantum disk under non-resonant, intense laser radiation

    NASA Astrophysics Data System (ADS)

    Niculescu, E. C.

    2017-04-01

    By considering a three-level ladder-type system under electromagnetically induced transparency, the absorption and dispersion of the probe field in a GaAs disk-like quantum dot under simultaneous action of the electric field and non-resonant, intense laser radiation are investigated. We found that some characteristics such as the width of the transmission window and group velocity can be efficiently manipulated by tuning the control field intensity, non-resonant radiation amplitude and electric field strength. Our results may be relevant for future investigations of the optical process in semiconductor quantum structures and for the technological applications in solid- state optoelectronics.

  13. Rabi oscillations and self-induced transparency in InAs/InP quantum dot semiconductor optical amplifier operating at room temperature.

    PubMed

    Karni, Ouri; Capua, Amir; Eisenstein, Gadi; Sichkovskyi, Vitalii; Ivanov, Vitalii; Reithmaier, Johann Peter

    2013-11-04

    We report direct observations of Rabi oscillations and self-induced transparency in a quantum dot optical amplifier operating at room temperature. The experiments make use of pulses whose durations are shorter than the coherence time which are characterized using Cross-Frequency-Resolved Optical Gating. A numerical model which solves the Maxwell and Schrödinger equations and accounts for the inhomogeneously broadened nature of the quantum dot gain medium confirms the experimental results. The model is also used to explain the relationship between the observability of Rabi oscillations, the pulse duration and the homogeneous and inhomogeneous spectral widths of the semiconductor.

  14. Electromagnetically induced absorption and transparency in degenerate two level systems of metastable Kr atoms and measurement of Landé g-factor

    NASA Astrophysics Data System (ADS)

    Kale, Y. B.; Tiwari, V. B.; Mishra, S. R.; Singh, S.; Rawat, H. S.

    2016-12-01

    We report electromagnetically induced absorption (EIA) and transparency (EIT) resonances of sub-natural linewidth in degenerate two level systems (DTLSs) of metastable 84Kr (84Kr*) and 83Kr (83Kr*) atoms. Using the spectrally narrow EIA signals obtained corresponding to the closed hyperfine transition 4p55s[3/2]2(F=13/2) to 4p55p[5/2]3(F‧ = 15 / 2) in 83Kr* atom, we have measured the Landé g-factor (gF) for the lower hyperfine level involved in this transition by application of small values of magnetic field of few Gauss.

  15. Vanishing of dipole matrix elements at level crossings.

    NASA Technical Reports Server (NTRS)

    Kocher, C. A.

    1972-01-01

    Demonstration that the vanishing of certain coupling matrix elements at level crossings follow from angular momentum commutation relations. A magnetic dipole transition having delta M = plus or minus 1, induced near a crossing of the levels in a nonzero magnetic field, is found to have a dipole matrix element comparable to or smaller than the quotient of the level separation and the field. This result also applies in the analogous electric field electric dipole case.

  16. Optical Dipole Noise.

    NASA Astrophysics Data System (ADS)

    Bacon, Allan Mclain

    1995-01-01

    Optical dipole fluctuations in atoms play an important role in diverse physical phenomena: they limit the signal to background ratio in spectroscopic measurements, and thus limit the accuracy of atomic clocks; they determine the minimum temperature that can be obtained in laser cooling and in optical traps; and, they place a limit on squeezed state experiments. Although there have been many theoretical and experimental studies of noise in radiating atomic systems, the previous work has not provided a complete physical picture of the distinct sources of optical dipole noise. Hence, a detailed study of optical dipole fluctuations in a simple radiating system is of fundamental and pedagogical value. This dissertation presents measurements of optical dipole noise in a particularly simple system consisting of long-lived, coherently driven two-level atoms in an atomic beam. We use atoms with a long radiative lifetime, because the small spontaneous emission rate permits analysis of the noise spectra in terms of a simple fluctuating Bloch vector picture, without decay. The observed noise spectra exhibit manifestly different structure for radiation which is in-phase or out-of-phase with the driving field. The spectra and corresponding analysis afford clear insights into the roles played by three distinct sources of atomic noise: Spontaneous emission, phase-dependent Bloch vector projection noise, and phase-dependent mean dipole Poisson noise. Spontaneous emission and phase-dependent Bloch vector projection noise arise from quantum fluctuations in the optical dipole moment of single atoms. Phase-dependent mean dipole Poisson noise arises from fluctuations in the number of radiating atoms. Two novel experimental techniques permit sensitive measurement of optical dipole noise. First, the signals from two identically prepared experimental regions are subtracted. This method cancels the excess noise in the measured quadrature signal in addition to canceling the excess noise in

  17. Transparent electronics and prospects for transparent displays

    NASA Astrophysics Data System (ADS)

    Wager, John F.; Valencia, Melinda M.; Bender, Jeffrey P.; Norris, Benjamin J.; Chiang, Hai Q.; Hong, David; Norris, Luke N.; Harman, Taran V.; Park, Sangmoon; Anderson, Jeremy T.; Park, Cheol-Hee; Keszler, Douglas A.; Tate, Janet; Yanagi, Hiroshi; Price, Matthew F.; Hoffman, R. L.

    2003-09-01

    Transparent electronics is a nascent technology whose objective is the realization of invisible electronic circuits. Part of the impetus for the development of transparent electronics is the recent availability of p-type transparent conductive oxides (TCOs). With the emergence of p-type TCOs, in addition to conventional n-type TCOs such as indium-tin oxide, tin oxide, and zinc oxide, fabrication of transparent bipolar electronic devices becomes feasible. The first part of this paper reviews TCOs and discusses our work in the development of p-TCOs and alternative TC materials (e.g. sulfides). We have recently invented a novel, n-channel, accumulation-mode transparent thin-film transistor (TTFT). This TTFT is highly transparent, has very little light sensitivity, and exhibits electrical characteristics that appear to be suitable for implementation as a transparent select-transistor in each pixel of an active-matrix liquid-crystal display (AMLCD). Moreover, the processing technology used to fabricate this device is relatively simple and appears to be compatible with inexpensive glass substrate technology. The second part of this paper focuses on TTFTs. If transparent electronics is employed to realize transparent back-plane electronic drivers on transparent substrates, fabrication of a transparent display becomes feasible. The third part of this paper offers an approach for realization of a transparent display.

  18. Transparent switchboard

    NASA Technical Reports Server (NTRS)

    Rasmussen, H. P. (Inventor)

    1973-01-01

    A tin oxide coating is formed on a plate of glass and the coating is then etched away from the glass in thin lines to form separate electrical conductors which extend to one end of the plate and connect to either a vertical (column) or horizontal (row) position sensing SCR circuit. A thin transparent insulating coating is formed over the oxide layer except at selected touch points which are positioned in a matrix pattern of vertical columns and horizontal rows. Touching one of these points with a finger bridges the thin line between adjacent conductors to activate trigger circuits in the particular row and column sensing circuits associated with the point touched. The row and column sensing circuits are similar and are powered with a low frequency, ac voltage source. The source for the row circuits is 180 out of phase with the source for the column circuits so that one circuit acts as ground for the other during half of the supply voltage cycle. The signals from the sensing circuits are input to a logic circuit which determines the presence of a valid touch, stores a binary matrix number associated with the touched point, signals a computer of the presence of a stored number and prevents storage of a new number before receiving an enable signal from the computer.

  19. Transparent screens.

    PubMed

    Rosenthal, R J

    1988-01-01

    There is a kind of transitional phenomenon found among certain borderline patients which is quite distinct from Winnicott's transitional object. These are patients who are preoccupied with maintaining proper physical distance from their objects, in order to regulate anxieties about isolation on the one hand, and identity-annihilating closeness on the other. Since they believe the activity of looking to be intrusive and devouring, hence dangerous, transparent screens are interposed between self and other, and serve as protective barriers. These screens function intrapsychically as well, to split off or hide those aspects of the self felt to be unacceptable. The analyst may witness the failure of the screen in several ways: it may create too great a distance, isolating the individual and keeping him from life; it may become contaminated by projections and turn into a persecutor, or trap the individual, a state of intolerable claustrophobia; most dramatically, it may suddenly shatter. The latter is associated with psychosis and death, and its appearance may be a harbinger of suicide.

  20. Suppression of stimulated Raman scattering by an electromagnetically-induced-transparency-like scheme and its application for super-resolution microscopy

    NASA Astrophysics Data System (ADS)

    Gong, Li; Wang, Haifeng

    2015-08-01

    We theoretically investigate a scheme in which stimulated Raman scattering (SRS) can be suppressed by coherently controlling the coupling between molecular states. In conventional SRS, two laser beams at different frequencies interact resonantly with molecular vibration to induce a gain and a loss for the two beams, respectively. In our scheme, a third beam is introduced to couple the vibrational state to another coupling state. As a result, SRS is suppressed in a way analogous to electromagnetically induced transparency. We calculated the SRS signal analytically by the density matrix approach, and investigated the feasibility of this scheme for real molecular imaging. In SRS microscopy, a donut-shaped coupling laser can be used to suppress the SRS signal from the rim part of the focal spot, leading to super-resolution. Based on our numerical studies, the lateral resolution starts to be enhanced when the coupling laser intensity exceeds 0.1 TW /c m2 at picosecond pulse duration.

  1. Dipole-dipole dispersion interactions between neutrons

    NASA Astrophysics Data System (ADS)

    Babb, James F.; Higa, Renato; Hussein, Mahir S.

    2017-06-01

    We investigate the long-range interactions between two neutrons utilizing recent data on the neutron static and dynamic electric and magnetic dipole polarizabilities. The resulting long-range potentials are used to make quantitative comparisons between the collisions of a neutron with a neutron and a neutron with a proton. We also assess the importance of the first pion production threshold and first excited state of the nucleon, the Δ-resonance (J^{π} = +3/2, I = 3/2). We found both dynamical effects to be quite relevant for distances r between ˜ 50 fm up to ˜ 103 fm in the nn system, the neutron-wall system and in the wall-neutron-wall system, reaching the expected asymptotic limit beyond that. Relevance of our findings to the confinement of ultra cold neutrons inside bottles is discussed.

  2. Experiments with Dipole Antennas

    ERIC Educational Resources Information Center

    Kraftmakher, Yaakov

    2009-01-01

    Employment of a data-acquisition system for data collection and calculations makes experiments with antennas more convenient and less time consuming. The determined directional patterns of the dipole antennas of different lengths are in reasonable agreement with theory. The enhancement of the signal by using a reflector is demonstrated, and a…

  3. Dipole soliton-vortices.

    PubMed

    Kartashov, Yaroslav V; Ferrando, Albert; García-March, Miguel-Angel

    2007-08-01

    On universal symmetry grounds, we analyze the existence of a new type of discrete-symmetry vortex solitons that can be considered as coherent states of dipole solitons carrying a nonzero topological charge. Remarkably, they can be also interpreted as excited angular Bloch states. The stability of new soliton states is elucidated numerically.

  4. Experiments with Dipole Antennas

    ERIC Educational Resources Information Center

    Kraftmakher, Yaakov

    2009-01-01

    Employment of a data-acquisition system for data collection and calculations makes experiments with antennas more convenient and less time consuming. The determined directional patterns of the dipole antennas of different lengths are in reasonable agreement with theory. The enhancement of the signal by using a reflector is demonstrated, and a…

  5. Geometrical Simplification of the Dipole-Dipole Interaction Formula

    ERIC Educational Resources Information Center

    Kocbach, Ladislav; Lubbad, Suhail

    2010-01-01

    Many students meet dipole-dipole potential energy quite early on when they are taught electrostatics or magnetostatics and it is also a very popular formula, featured in encyclopedias. We show that by a simple rewriting of the formula it becomes apparent that, for example, by reorienting the two dipoles, their attraction can become exactly twice…

  6. Geometrical Simplification of the Dipole-Dipole Interaction Formula

    ERIC Educational Resources Information Center

    Kocbach, Ladislav; Lubbad, Suhail

    2010-01-01

    Many students meet dipole-dipole potential energy quite early on when they are taught electrostatics or magnetostatics and it is also a very popular formula, featured in encyclopedias. We show that by a simple rewriting of the formula it becomes apparent that, for example, by reorienting the two dipoles, their attraction can become exactly twice…

  7. Half wavelength dipole antennas over stratified media

    NASA Technical Reports Server (NTRS)

    Latorraca, G. A.

    1972-01-01

    Theoretical solutions of the fields induced by half-wavelength, horizontal, electric field dipoles (HEDS) are determined based on studies of infinitesimal, horizontal, electric field dipoles over low loss plane-stratified media. To determine these solutions, an approximation to the current distribution of a half-wavelength HED is derived and experimentally verified. Traverse and antenna measurements obtained on the Athabasca Glacier in the summer of 1971 are related to the characteristics of the transmitting antenna design, and the measurement techniques and field equipment used in the glacier trials are described and evaluated.

  8. Rashba and Dresselhaus spin-orbit couplings effects on electromagnetically induced transparency of a lens-shaped quantum dot: External electric and magnetic fields

    NASA Astrophysics Data System (ADS)

    Zamani, A.; Setareh, F.; Azargoshasb, T.; Niknam, E.; Mohammadhosseini, E.

    2017-06-01

    In this article the spin of electron as well as simultaneous effects of Rashba and Dresselhaus spin-orbit interactions are considered for a lens-shaped GaAs quantum dot and the influences of applied electric field and Zeeman effect on the electromagnetically induced transparency (EIT) of this system are investigated. To do so, the absorption, refractive index as well as the group velocity of the probe light pulse are presented and discussed. Study of the absorption and refractive index reveals that, at a particular frequency of probe field, absorption diminishes, refractive index becomes unity and so the EIT occurs. Furthermore, the investigation of group velocity show that, around such frequency the probe propagation is sub-luminal, which shifts to super-luminal for higher and lower frequencies. Our results illustrate that the EIT frequency, transparency window and sub(super)-luminal frequency intervals are strongly sensitive to applied fields in the presence of spin-orbit couplings. It is found that, in comparison with the investigations with negligence of spin, the EIT behavior under the effects of applied fields are quite different.

  9. Stretchable and transparent electrodes based on patterned silver nanowires by laser-induced forward transfer for non-contacted printing techniques.

    PubMed

    Araki, Teppei; Mandamparambil, Rajesh; van Bragt, Dirk Martinus Peterus; Jiu, Jinting; Koga, Hirotaka; van den Brand, Jeroen; Sekitani, Tsuyoshi; den Toonder, Jaap M J; Suganuma, Katsuaki

    2016-11-11

    Silver nanowires (AgNWs) are excellent candidate electrode materials in next-generation wearable devices due to their high flexibility and high conductivity. In particular, patterning techniques for AgNWs electrode manufacture are very important in the roll-to-roll printing process to achieve high throughput and special performance production. It is also essential to realize a non-contact mode patterning for devices in order to keep the pre-patterned components away from mechanical damages. Here, we report a successful non-contact patterning of AgNWs-based stretchable and transparent electrodes by laser-induced forward transfer (LIFT) technique. The technique was used to fabricate a 100% stretchable electrode with a width of 200 μm and electrical resistivity 10(-4) Ωcm. Experiments conducted integrating the stretchable electrode on rubber substrate in which LED was pre-fabricated showed design flexibility resulting from non-contact printing. Further, a patterned transparent electrode showed over 80% in optical transmittance and less than 100 Ω sq(-1) in sheet resistance by the optimized LIFT technique.

  10. Stretchable and transparent electrodes based on patterned silver nanowires by laser-induced forward transfer for non-contacted printing techniques

    NASA Astrophysics Data System (ADS)

    Araki, Teppei; Mandamparambil, Rajesh; Martinus Peterus van Bragt, Dirk; Jiu, Jinting; Koga, Hirotaka; van den Brand, Jeroen; Sekitani, Tsuyoshi; den Toonder, Jaap M. J.; Suganuma, Katsuaki

    2016-11-01

    Silver nanowires (AgNWs) are excellent candidate electrode materials in next-generation wearable devices due to their high flexibility and high conductivity. In particular, patterning techniques for AgNWs electrode manufacture are very important in the roll-to-roll printing process to achieve high throughput and special performance production. It is also essential to realize a non-contact mode patterning for devices in order to keep the pre-patterned components away from mechanical damages. Here, we report a successful non-contact patterning of AgNWs-based stretchable and transparent electrodes by laser-induced forward transfer (LIFT) technique. The technique was used to fabricate a 100% stretchable electrode with a width of 200 μm and electrical resistivity 10-4 Ωcm. Experiments conducted integrating the stretchable electrode on rubber substrate in which LED was pre-fabricated showed design flexibility resulting from non-contact printing. Further, a patterned transparent electrode showed over 80% in optical transmittance and less than 100 Ω sq-1 in sheet resistance by the optimized LIFT technique.

  11. Can nature's design be improved upon? High strength, transparent nacre-like nanocomposites with double network of sacrificial cross links.

    PubMed

    Podsiadlo, Paul; Kaushik, Amit K; Shim, Bong Sup; Agarwal, Ashish; Tang, Zhiyong; Waas, Anthony M; Arruda, Ellen M; Kotov, Nicholas A

    2008-11-20

    The preparation of a high-strength and highly transparent nacre-like nanocomposite via layer-by-layer assembly technique from poly(vinyl alcohol) (PVA) and Na+-montmorillonite clay nanosheets is reported in this article. We show that a high density of weak bonding interactions between the polymer and the clay particles: hydrogen, dipole-induced dipole, and van der Waals undergoing break-reform deformations, can lead to high strength nanocomposites: sigmaUTS approximately 150 MPa and E' approximately 13 GPa. Further introduction of ionic bonds into the polymeric matrix creates a double network of sacrificial bonds which dramatically increases the mechanical properties: sigmaUTS approximately 320 MPa and E' approximately 60 GPa.

  12. Pygmy dipole resonance and dipole polarizability in {sup 90}Zr

    SciTech Connect

    Iwamoto, C.; Tamii, A.; Shima, T.; Hashimoto, T.; Suzuki, T.; Fujita, H.; Hatanaka, K.; Utsunomiya, H.; Akimune, H.; Yamagata, T.; Okamoto, A.; Kondo, T.; Nakada, H.; Kawabata, T.; Fujita, Y.; Matsubara, H.; Shimbara, Y.; Nagashima, M.; Sakuda, M.; Mori, T.; and others

    2014-05-02

    Electric dipole (E1) reduced transition probability B(E1) of {sup 90}Zr was obtained by the inelastic proton scattering near 0 degrees using a 295 MeV proton beam and multipole decomposition analysis of the angular distribution by the distorted-wave Born approximation with the Hartree-Fock plus random-phase approximation model and inclusion of El Coulomb excitation, and the E1 strength of the pygmy dipole resonance was found in the vicinity of the neutron threshold in the low-energy tail of the giant dipole resonance. Using the data, we plan to determine the precise dipole polarizability α{sub D} which is defined as an inversely energy-weighted sum value of the elecrric dipole strength. The dipole polarizability is expected to constrain the symmetry energy term of the neutron matter equation of state. Thus systematical measurement of the dipole polarizability is important.

  13. Pygmy dipole resonance and dipole polarizability in 90Zr

    NASA Astrophysics Data System (ADS)

    Iwamoto, C.; Tamii, A.; Utsunomiya, H.; Akimune, H.; Nakada, H.; Shima, T.; Hashimoto, T.; Yamagata, T.; Kawabata, T.; Fujita, Y.; Matsubara, H.; Suzuki, T.; Fujita, H.; Shimbara, Y.; Nagashima, M.; Sakuda, M.; Mori, T.; Izumi, T.; Okamoto, A.; Kondo, T.; Lui, T.-W.; Bilgier, B.; Kozer, H. C.; Hatanaka, K.

    2014-05-01

    Electric dipole (E1) reduced transition probability B(E1) of 90Zr was obtained by the inelastic proton scattering near 0 degrees using a 295 MeV proton beam and multipole decomposition analysis of the angular distribution by the distorted-wave Born approximation with the Hartree-Fock plus random-phase approximation model and inclusion of El Coulomb excitation, and the E1 strength of the pygmy dipole resonance was found in the vicinity of the neutron threshold in the low-energy tail of the giant dipole resonance. Using the data, we plan to determine the precise dipole polarizability αD which is defined as an inversely energy-weighted sum value of the elecrric dipole strength. The dipole polarizability is expected to constrain the symmetry energy term of the neutron matter equation of state. Thus systematical measurement of the dipole polarizability is important.

  14. Phase shift multiplication effect of all-optical analog to electromagnetically induced transparency in two micro-cavities side coupled to a waveguide system

    SciTech Connect

    Wang, Boyun; Wang, Tao Tang, Jian; Li, Xiaoming; Dong, Chuanbo

    2014-01-14

    We propose phase shift multiplication effect of all-optical analog to electromagnetically induced transparency in two photonic crystal micro-cavities side coupled to a waveguide system through external optical pump beams. With dynamically tuning the propagation phase of the line waveguide, the phase shift of the transmission spectrum in two micro-cavities side coupled to a waveguide system is doubled along with the phase shift of the line waveguide. π-phase shift and 2π-phase shift of the transmission spectrum are obtained when the propagation phase of the line waveguide is tuned to 0.5π-phase shift and π-phase shift, respectively. All observed schemes are analyzed rigorously through finite-difference time-domain simulations and the coupled-mode formalism. These results show a new direction to the miniaturization and the low power consumption of microstructure integration photonic devices in optical communication and quantum information processing.

  15. Measurement of absolute transition frequencies of {sup 87}Rb to nS and nD Rydberg states by means of electromagnetically induced transparency

    SciTech Connect

    Mack, Markus; Karlewski, Florian; Hattermann, Helge; Hoeckh, Simone; Jessen, Florian; Cano, Daniel; Fortagh, Jozsef

    2011-05-15

    We report the measurement of absolute excitation frequencies of {sup 87}Rb to nS and nD Rydberg states. The Rydberg transition frequencies are obtained by observing electromagnetically induced transparency on a rubidium vapor cell. The accuracy of the measurement of each state is < or approx. 1 MHz, which is achieved by frequency stabilizing the two diode lasers employed for the spectroscopy to a frequency comb and a frequency comb calibrated wavelength meter, respectively. Based on the spectroscopic data we determine the quantum defects of {sup 87}Rb, and compare it with previous measurements on {sup 85}Rb. We determine the ionization frequency from the 5S{sub 1/2}(F=1) ground state of {sup 87}Rb to 1010.029 164 6(3)THz, providing the binding energy of the ground state with an accuracy improved by two orders of magnitude.

  16. On-chip nanostructuring and impedance trimming of transparent and flexible ITO electrodes by laser induced coherent sub-20 nm cuts

    NASA Astrophysics Data System (ADS)

    Afshar, Maziar; Leber, Moritz; Poppendieck, Wigand; König, Karsten; Seidel, Helmut; Feili, Dara

    2016-01-01

    In this work, the effect of laser-induced nanostructuring of transparent indium tin oxide (ITO) electrodes on flexible glass is investigated. Multi-electrode arrays (MEA) for electrical and optical characterization of biological cells were fabricated using standard MEMS technologies. Optimal sputter parameters concerning oxygen flow, sputter power and ambient pressure for ITO layers with both good optical and electrical properties were determined. Afterwards, coherent sub-20 nm wide and 150 nm deep nanocuts of many micrometers in length were generated within the ITO electrodes by a sub-15 femtosecond (fs) pulsed laser. The influence of laser processing on the electrical and optical properties of electrodes was investigated. The electrochemical impedance of the manufactured electrodes was measured before and after laser modification using electrochemical impedance spectroscopy. A small reduction in electrode impedance was observed. These nanostructured electrodes show also polarizing effects by the visible spectrum.

  17. Three-dimensional footprint of optical breakdown in transparent dielectrics induced by femtosecond pulsed lasers and the effect of laser energy absorption

    NASA Astrophysics Data System (ADS)

    Mahdieh, M. H.; Mortezaei, Z.

    2015-02-01

    In this paper optical breakdown process in dielectrics induced by femtosecond pulsed lasers was calculated numerically and 3-dimensional footprint of the breakdown region was simulated. Rate equation was used to calculate the temporal and spatial evolution of free electron density. In these simulations the role of tunneling ionization in free electron generation has been considered. Also absorbed energy from the pulse via multiphoton and inverse bremsstrahlung absorption was calculated numerically. The results show that the absorption of the propagating laser through the initially transparent dielectric is important and its ignorance may results in significant error in estimating the breakdown geometry, and volume. According to the simulation results in compare with our previous calculations, smaller and asymmetrical breakdown footprint is obtained if the absorption is considered in the calculations.

  18. Using frequency detuning to improve the sensitivity of electric field measurements via electromagnetically induced transparency and Autler-Townes splitting in Rydberg atoms

    SciTech Connect

    Simons, Matt T.; Gordon, Joshua A.; Holloway, Christopher L.; Anderson, David A.; Miller, Stephanie A.; Raithel, Georg

    2016-04-25

    In this work, we demonstrate an approach for improved sensitivity in weak radio frequency (RF) electric-field strength measurements using Rydberg electromagnetically induced transparency (EIT) in an atomic vapor. This is accomplished by varying the RF frequency around a resonant atomic transition and extrapolating the weak on-resonant field strength from the resulting off-resonant Autler-Townes (AT) splittings. This measurement remains directly traceable to SI compared to previous techniques, precluding any knowledge of experimental parameters such as optical beam powers as is the case when using the curvature of the EIT line shape to measure weak fields. We use this approach to measure weak RF fields at 182 GHz and 208 GHz demonstrating improvement greater than a factor of 2 in the measurement sensitivity compared to on-resonant AT splitting RF electric field measurements.

  19. High electrostrictive strain induced by defect dipoles in acceptor-doped (K0.5Na0.5)NbO3 ceramics

    NASA Astrophysics Data System (ADS)

    Dai, Ye-Jing; Zhao, Yong-Jie; Zhao, Zhe; Zhao, Zhi-Hao; Zhou, Qi-Wu; Zhang, Xiao-Wen

    2016-07-01

    Acceptor doping is an efficient method to improve ferroelectric material performance through the formation of defect dipoles. Here, a high electrostrictive strain of 0.16-0.19%, and large d33\\ast of  >300 pm V-1 are obtained in CuO-doped (K0.5Na0.5)NbO3 ceramics. We analyzed the orientation relationship and the interaction between defect dipole polarization (P d) along <0 0 1> orientation and spontaneous polarization (P s) parallel to <1 1 0> in orthorhombic (K0.5Na0.5)NbO3. Thus, a ‘coupling effect’ mechanism was suggested to explain how the P d and P s can work together to contribute to the electrostrictive strains in this lead-free piezoelectric ceramic.

  20. Relativistically induced transparency acceleration of light ions by an ultrashort laser pulse interacting with a heavy-ion-plasma density gradient

    NASA Astrophysics Data System (ADS)

    Sahai, Aakash A.; Tsung, Frank S.; Tableman, Adam R.; Mori, Warren B.; Katsouleas, Thomas C.

    2013-10-01

    The relativistically induced transparency acceleration (RITA) scheme of proton and ion acceleration using laser-plasma interactions is introduced, modeled, and compared to the existing schemes. Protons are accelerated with femtosecond relativistic pulses to produce quasimonoenergetic bunches with controllable peak energy. The RITA scheme works by a relativistic laser inducing transparency [Akhiezer and Polovin, Zh. Eksp. Teor. Fiz 30, 915 (1956); Kaw and Dawson, Phys. FluidsPFLDAS0031-917110.1063/1.1692942 13, 472 (1970); Max and Perkins, Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.27.1342 27, 1342 (1971)] to densities higher than the cold-electron critical density, while the background heavy ions are stationary. The rising laser pulse creates a traveling acceleration structure at the relativistic critical density by ponderomotively [Lindl and Kaw, Phys. FluidsPFLDAS0031-917110.1063/1.1693437 14, 371 (1971); Silva , Phys. Rev. E1063-651X10.1103/PhysRevE.59.2273 59, 2273 (1999)] driving a local electron density inflation, creating an electron snowplow and a co-propagating electrostatic potential. The snowplow advances with a velocity determined by the rate of the rise of the laser's intensity envelope and the heavy-ion-plasma density gradient scale length. The rising laser is incrementally rendered transparent to higher densities such that the relativistic-electron plasma frequency is resonant with the laser frequency. In the snowplow frame, trace density protons reflect off the electrostatic potential and get snowplowed, while the heavier background ions are relatively unperturbed. Quasimonoenergetic bunches of velocity equal to twice the snowplow velocity can be obtained and tuned by controlling the snowplow velocity using laser-plasma parameters. An analytical model for the proton energy as a function of laser intensity, rise time, and plasma density gradient is developed and compared to 1D and 2D PIC OSIRIS [Fonseca , Lect. Note Comput. Sci.9783