WorldWideScience

Sample records for cavity resonators

  1. RESONANT CAVITY EXCITATION SYSTEM

    Science.gov (United States)

    Baker, W.R.; Kerns, Q.A.; Riedel, J.

    1959-01-13

    An apparatus is presented for exciting a cavity resonator with a minimum of difficulty and, more specifically describes a sub-exciter and an amplifier type pre-exciter for the high-frequency cxcitation of large cavities. Instead of applying full voltage to the main oscillator, a sub-excitation voltage is initially used to establish a base level of oscillation in the cavity. A portion of the cavity encrgy is coupled to the input of the pre-exciter where it is amplified and fed back into the cavity when the pre-exciter is energized. After the voltage in the cavity resonator has reached maximum value under excitation by the pre-exciter, full voltage is applied to the oscillator and the pre-exciter is tunned off. The cavity is then excited to the maximum high voltage value of radio frequency by the oscillator.

  2. Hyperbolic Resonances of Metasurface Cavities

    CERN Document Server

    Keene, David

    2015-01-01

    We propose a new class of optical resonator structures featuring one or two metasurface reflectors or metacavities and predict that such resonators support novel hyperbolic resonances. As an example of such resonances we introduce hyperbolic Tamm plasmons (HTPs) and hyperbolic Fabry-Perot resonances (HFPs). The hyperbolic optical modes feature low-loss incident power re-distribution over TM and TE polarization output channels, clover-leaf anisotropic dispersion, and other unique properties which are tunable and are useful for multiple applications.

  3. The CEBAF Separator Cavity Resonance Control System

    CERN Document Server

    Wissmann, Mark J; Hovater, Curt; Plawski, Tomasz

    2005-01-01

    The CEBAF energy upgrade from 6 GeV to 12GeV will increase the range of beam energies available to the experimental halls. RF deflection cavities (separators) are used to direct the electron beam to the three experimental halls. Consequently with the increase in RF separator cavity gradient needed for the higher energies, RF power will also increase requiring the cavities to have active resonance control. At the 6 GeV energy, the cavities are tuned mechanically and then stabilized with Low Conductivity Water (LCW), which is maintained at constant temperature of 95o Fahrenheit. This is no longer feasible and an active resonance control system, that controls both water temperature and flow has been built. The system uses a commercial PLC with embedded PID controls to control water temperature and flow to the cavities. The system allows the operator to remotely adjust temperature/flow and consequently cavity resonance for the full range of beam energies. Ultimately closed loop control will be maintained by monit...

  4. Piezoelectric Voltage Coupled Reentrant Cavity Resonator

    CERN Document Server

    Carvalho, Natalia C; Floch, Jean-Michel Le; Tobar, Michael Edmund

    2014-01-01

    A piezoelectric voltage coupled microwave reentrant cavity has been developed. The central cavity post is bonded to a piezoelectric actuator allowing the voltage control of small post displacements over a high dynamic range. We show that such a cavity can be implemented as a voltage tunable resonator, a transducer for exciting and measuring mechanical modes of the structure and a transducer for measuring comparative sensitivity of the piezoelectric material. Experiments were conducted at room and cryogenic temperatures with results verified using Finite Element software.

  5. Stafne bone cavity--magnetic resonance imaging.

    Science.gov (United States)

    Segev, Yoram; Puterman, Max; Bodner, Lipa

    2006-07-01

    A case of Stafne bone cavity (SBC) affecting the body of the mandible of a 51-year-old female is reported. The imaging modalities included panoramic radiograph, computed tomography (CT) and magnetic resonance (MR) imaging. Panoramic radiograph and CT were able to determine the outline of the cavity and its three dimensional shape, but failed to precisely diagnose the soft tissue content of the cavity. MR imaging demonstrated that the bony cavity is filled with soft tissue that is continuous and identical in signal with that of the submandibular salivary gland. Based on the MR imaging a diagnosis of SBC was made and no further studies or surgical treatment were initiated. MR imaging should be considered the diagnostic technique in cases where SBC is suspected. Recognition of the lesion should preclude any further treatment or surgical exploration.

  6. Optical cavity resonator in an expanding universe

    Science.gov (United States)

    Kopeikin, Sergei M.

    2015-02-01

    We study the cosmological evolution of frequency of a standing electromagnetic wave in a resonant optical cavity placed to the expanding manifold described by the Robertson-Walker metric. Because of the Einstein principle of equivalence (EEP), one can find a local coordinate system (a local freely falling frame), in which spacetime is locally Minkowskian. However, due to the conformal nature of the Robertson-Walker metric the conventional transformation to the local inertial coordinates introduces ambiguity in the physical interpretation of the local time coordinate, . Therefore, contrary to a common-sense expectation, a straightforward implementation of EEP alone does not allow us to unambiguously decide whether atomic clocks based on quantum transitions of atoms, ticks at the same rate as the clocks based on electromagnetic modes of a cavity. To resolve this ambiguity we have to analyse the cavity rigidity and the oscillation of its electromagnetic modes in an expanding universe by employing the full machinery of the Maxwell equations irrespectively of the underlying theory of gravity. We proceed in this way and found out that the size of the cavity and the electromagnetic frequency experience an adiabatic drift in conformal (unphysical) coordinates as the universe expands in accordance with the Hubble law. We set up the oscillation equation for the resonant electromagnetic modes, solve it by the WKB approximation, and reduce the coordinate-dependent quantities to their counterparts measured by a local observer who counts time with atomic clock. The solution shows that there is a perfect mutual cancellation of the adiabatic drift of cavity's frequency by space transformation to local coordinates and the time counted by the clocks based on electromagnetic modes of cavity has the same rate as that of atomic clocks. We conclude that if general relativity is correct and the local expansion of space is isotropic there should be no cosmological drift of frequency of a

  7. Resonant cavity monitors for charged beam measurements.

    Science.gov (United States)

    Rutledge, Gary A.

    2003-04-01

    The G_zero experiment at Jefferson Lab, will measure the strange quark content of the proton as it contributes to the proton's charge and magnetic properties. Parity violating elastic electron scattering is being used to measure the physics asymmetry to better than 1 part in 10^7. Helicity correlated properties of the electron beam used in this experiment must be measured to better than 1 in 10^7 over the course of the experiment. G_zero employs two types of beam monitors for this purpose. Standard, 4-wire, ``strip-line'' monitors measure beam positions with a resolution of 20microns. Another type of monitor, Beam Resonant Cavities are being tested. Two sets of three cavities are used to measure beam position in X and Y, as well as beam current. Presented will be the performance and evaluation of these cavities including their theoretical versus actual operation, their noise characteristics, and signal resolution. These cavities can be paired with either linear or logarithmic amplifier electronics. Overall performance of these cavity systems including amplifiers will be compared with standard 'strip-line' monitors.

  8. Optical cavity resonator in an expanding universe

    CERN Document Server

    Kopeikin, Sergei

    2014-01-01

    We study evolution of frequency of a standing electromagnetic (EM) wave in a resonant optical cavity placed to the expanding manifold described by the Robertson-Walker metric. One builds a local coordinate system in which spacetime is locally Minkowskian. However, due to the conformal nature of the Robertson-Walker metric the conventional transformation to the local inertial coordinates introduces ambiguity in the physical interpretation of the local time coordinate. Therefore, contrary to a common-sense expectation, a straightforward implementation of EEP alone does not allow us to decide whether atomic clocks ticks at the same rate as the clocks based on EM modes of a cavity. To resolve the ambiguity we analyzed the cavity rigidity and the oscillation of its EM modes in an expanding universe by employing the Maxwell equations. We found out that both the size of the cavity and the EM frequency experience an adiabatic drift in conformal coordinates as the universe expands. We set up the oscillation equation f...

  9. Tunable cavity resonator including a plurality of MEMS beams

    Energy Technology Data Exchange (ETDEWEB)

    Peroulis, Dimitrios; Fruehling, Adam; Small, Joshua Azariah; Liu, Xiaoguang; Irshad, Wasim; Arif, Muhammad Shoaib

    2015-10-20

    A tunable cavity resonator includes a substrate, a cap structure, and a tuning assembly. The cap structure extends from the substrate, and at least one of the substrate and the cap structure defines a resonator cavity. The tuning assembly is positioned at least partially within the resonator cavity. The tuning assembly includes a plurality of fixed-fixed MEMS beams configured for controllable movement relative to the substrate between an activated position and a deactivated position in order to tune a resonant frequency of the tunable cavity resonator.

  10. Theory of RF superconductivity for resonant cavities

    Science.gov (United States)

    Gurevich, Alex

    2017-03-01

    An overview of a theory of electromagnetic response of superconductors in strong radio-frequency (RF) electromagnetic fields is given with the emphasis on applications to superconducting resonant cavities for particle accelerators. The paper addresses fundamentals of the BCS surface resistance, the effect of subgap states and trapped vortices on the residual surface resistance at low RF fields, and a nonlinear surface resistance at strong fields, particularly the effect of the RF field suppression of the surface resistance. These issues are essential for the understanding of the field dependence of high quality factors Q({B}a)∼ {10}10{--}{10}11 achieved on the Nb cavities at 1.3–2 K in strong RF fields B a close to the depairing limit, and the extended Q({B}a) rise which has been observed on Ti and N-treated Nb cavities. Possible ways of further increase of Q({B}a) and the breakdown field by optimizing impurity concentration at the surface and by multilayer nanostructuring with materials other than Nb are discussed.

  11. THz parallel-plate waveguides with resonant cavities

    DEFF Research Database (Denmark)

    Reichel, Kimberly S.; Astley, Victoria; Iwaszczuk, Krzysztof;

    2015-01-01

    We characterize the terahertz resonance due to a cavity inside aparallel-plate waveguide, and discuss its use for refractive index sensing. Insidethe waveguide, we observe a broadband field enhancement associated with thisnarrowband resonance. © 2015 OSA....

  12. Ferrite-filled cavities for compact planar resonators

    Science.gov (United States)

    Keatley, P. S.; Durrant, C. J.; Berry, S. J.; Sirotkin, E.; Hibbins, A. P.; Hicken, R. J.

    2014-01-01

    Sub-wavelength metallic planar cavities, closed at one end, have been constructed by wrapping aluminium foil around teflon or ferrite slabs. Finite cavity width perturbs the fundamental cavity mode frequency of ferrite-filled cavities due to different permeability inside and outside of the cavity, in contrast to teflon-filled cavities, while the cavity length required to achieve a specific resonance frequency is significantly reduced for a ferrite-filled cavity. Ferrite-filled cavities may be excited by an in-plane alternating magnetic field and may be advantageous for high-frequency (HF) and ultra HF tagging and radio frequency identification of metallic objects within security, manufacturing, and shipping environments.

  13. Resonance Photon Generation in a Vibrating Cavity

    CERN Document Server

    Dodonov, V V

    1998-01-01

    The problem of photon creation from vacuum due to the nonstationary Casimir effect in an ideal one-dimensional Fabry--Perot cavity with vibrating walls is solved in the resonance case, when the frequency of vibrations is close to the frequency of some unperturbed electromagnetic mode: $\\omega_w=p(\\pi c/L_0)(1+\\delta)$, $|\\delta|\\ll 1$, (p=1,2,...). An explicit analytical expression for the total energy in all the modes shows an exponential growth if $|\\delta|$ is less than the dimensionless amplitude of vibrations $\\epsilon\\ll 1$, the increment being proportional to $p\\sqrt{\\epsilon^2-\\delta^2}$. The rate of photon generation from vacuum in the (j+ps)th mode goes asymptotically to a constant value $cp^2\\sin^2(\\pi j/p)\\sqrt{\\epsilon^2-\\delta^2}/[\\pi L_0 (j+ps)]$, the numbers of photons in the modes with indices p,2p,3p,... being the integrals of motion. The total number of photons in all the modes is proportional to $p^3(\\epsilon^2-\\delta^2) t^2$ in the short-time and in the long-time limits. In the case of st...

  14. Systematization of All Resonance Modes in Circular Dielectric Cavities

    NARCIS (Netherlands)

    Dettmann, C.P.; Morozov, G.V.; Sieber, M.; Waalkens, H.

    2009-01-01

    Circular dielectric cavities are key components for the construction of optic microresonators and microlasers. They are one of very few cases where the transcendental equations for complex eigenmodes (resonances) of an open system (dielectric cavity) can be found analytically in an exact manner. The

  15. Hybrid III-V/SOI resonant cavity enhanced photodetector

    DEFF Research Database (Denmark)

    Learkthanakhachon, Supannee; Taghizadeh, Alireza; Park, Gyeong Cheol;

    2016-01-01

    A hybrid III–V/SOI resonant-cavity-enhanced photodetector (RCE-PD) structure comprising a high-contrast grating (HCG) reflector, a hybrid grating (HG) reflector, and an air cavity between them, has been proposed and investigated. In the proposed structure, a light absorbing material is integrated...

  16. High Quality RF resonant cavity for high gradient linacs

    CERN Document Server

    TianXiu-fang,; Deguo, Xun; Kun, Liu; yong, Hou; Jian, Cheng

    2015-01-01

    In traditional accelerating structures, maximum amplitudes of accelerating fields are restricted by Joule heating losses in conducting walls and electron breakdown. In this paper, a composite accelerating cavity utilizing a resonant, periodic structure with a dielectric sphere located at a spherical conducting cavity center is presented. The presence of the dielectric in the central part of the resonance cavity shifts the magnetic fields maximum from regions close to the metallic wall towards the dielectric surface, which strongly lowers the skin effect losses in the wall. By using the existing ultra-low loss Sapphire dielectrics, we make theory analyze and numerical calculations by MATLAB, and further make simulated calculation by CST for comparison. The results show that all field components at the metallic wall are either zero or very small, so one can expect the cavity to be less prone to electrical breakdowns than the traditional cavity. And the quality factor Q can be three orders of magnitude higher th...

  17. Einstein-Maxwell equations for asymmetric resonant cavities

    CERN Document Server

    Frasca, Marco

    2015-01-01

    We analyze the behavior of electromagnetic fields inside a resonant cavity by solving Einstein--Maxwell field equations. It is shown that the modified geometry of space-time inside the cavity due to a propagating mode can affect the propagation of a laser beam. It is seen that components of laser light with a shifted frequency appear originating from the coupling between the laser field and the mode cavity due to gravity. The analysis is extended to the case of an asymmetric resonant cavity taken to be a truncated cone. It is shown that a proper choice of the geometrical parameters of the cavity and dielectric can make the gravitational effects significant for an interferometric setup. This could make possible to realize table-top experiments involving gravitational effects.

  18. Ray and wave chaos in asymmetric resonant optical cavities

    CERN Document Server

    Nöckel, J U; Noeckel, Jens U.

    1998-01-01

    Optical resonators are essential components of lasers and other wavelength-sensitive optical devices. A resonator is characterized by a set of modes, each with a resonant frequency omega and resonance width Delta omega=1/tau, where tau is the lifetime of a photon in the mode. In a cylindrical or spherical dielectric resonator, extremely long-lived resonances are due to `whispering gallery' modes in which light circulates around the perimeter trapped by total internal reflection. These resonators emit light isotropically. Recently, a new category of asymmetric resonant cavities (ARCs) has been proposed in which substantial shape deformation leads to partially chaotic ray dynamics. This has been predicted to give rise to a universal, frequency-independent broadening of the whispering-gallery resonances, and highly anisotropic emission. Here we present solutions of the wave equation for ARCs which confirm many aspects of the earlier ray-optics model, but also reveal interesting frequency-dependent effects charac...

  19. Adiabatic embedment of nanomechanical resonators in photonic microring cavities

    CERN Document Server

    Xiong, Chi; Li, Mo; Rooks, Michael; Tang, Hong X

    2014-01-01

    We report a circuit cavity optomechanical system in which a nanomechanical resonator is adiabatically embedded inside an optical ring resonator with ultralow transition loss. The nanomechanical device forms part of the top layer of a horizontal silicon slot ring resonator, which enables dispersive coupling to the dielectric substrate via a tapered nanogap. Our measurements show nearly uncompromised optical quality factors (Q) after the release of the mechanical beam.

  20. Fano resonance engineering in slanted cavities with hyperbolic metamaterials

    Science.gov (United States)

    Vaianella, Fabio; Maes, Bjorn

    2016-09-01

    We present the possibility to engineer Fano resonances using multilayered hyperbolic metamaterials. The proposed cavity designs are composed of multilayers with a central slanted part. The highly tunable resonances originate from the interference between a propagating and an evanescent mode inside the slanted section. The propagating mode can reach an extremely high effective index, making the realization of deeply subwavelength cavities possible, as small as 5 nm. The evanescent mode is rarely analyzed but plays an important role here, as its contribution determines the particular shape of the cavity characteristic. Moreover, these phenomena cannot be described using effective medium theory, and we provide a more rigorous analysis. The reported resonances are very sensitive to any structural changes and could be used for sensing applications.

  1. Indirect Coupling between Two Cavity Photon Systems via Ferromagnetic Resonance

    CERN Document Server

    Hyde, Paul; Harder, Michael; Match, Christophe; Hu, Can-Ming

    2016-01-01

    We experimentally realize indirect coupling between two cavity modes via strong coupling with the ferromagnetic resonance in Yttrium Iron Garnet (YIG). We find that some indirectly coupled modes of our system can have a higher microwave transmission than the individual uncoupled modes. Using a coupled harmonic oscillator model, the influence of the oscillation phase difference between the two cavity modes on the nature of the indirect coupling is revealed. These indirectly coupled microwave modes can be controlled using an external magnetic field or by tuning the cavity height. This work has potential for use in controllable optical devices and information processing technologies.

  2. Optical cavity coupled surface plasmon resonance sensing for enhanced sensitivity

    Institute of Scientific and Technical Information of China (English)

    Zheng Zheng; Xin Zhao; Jinsong Zhu; Jim Diamond

    2008-01-01

    A surface plasmon resonance (SPR) sensing system based on the optical cavity enhanced detection tech-nique is experimentally demonstrated. A fiber-optic laser cavity is built with a SPR sensor inside. By measuring the laser output power when the cavity is biased near the threshold point, the sensitivity, defined as the dependence of the output optical intensity on the sample variations, can be increased by about one order of magnitude compared to that of the SPR sensor alone under the intensity interrogation scheme. This could facilitate ultra-high sensitivity SPR biosensing applications. Further system miniaturization is possible by using integrated optical components and waveguide SPR sensors.

  3. Silicon waveguide polarization rotation Bragg grating with resonator cavity section

    Science.gov (United States)

    Okayama, Hideaki; Onawa, Yosuke; Shimura, Daisuke; Yaegashi, Hiroki; Sasaki, Hironori

    2017-04-01

    Bragg grating with resonator cavity that converts the input polarization to orthogonal polarization is reported. The device works similar to a Fabry–Pérot or ring resonators and very narrow polarization independent wavelength peak can be generated. The transfer matrix methods are used to examine the device characteristics. A 0.2-nm-wide polarization independent transmission wavelength peak was obtained by experiment. We also show theoretically using finite-difference-time-domain method that a flat-top response can be obtained by a two cavity structure.

  4. Cavity optomechanics on a microfluidic resonator

    CERN Document Server

    Kim, Kyu Hyun; Lee, Wonsuk; Liu, Jing; Tomes, Matthew; Fan, Xudong; Carmon, Tal

    2012-01-01

    Light pressure is known to excite or cool vibrations in microresonators for sensing quantum-optomechanical effects and we now show that it can be explored for investigations with liquids. Currently, optical resonances are utilized to detect analytes in liquids. However, optomechanical oscillations have never been excited when devices were immersed in liquid. This is because replacing the surrounding air with water inherently increases the acoustical impedance and the associated acoustical-radiation losses. Here we fabricate a hollow optomechanical bubble resonator with water inside, and use light pressure to excite 8 MHz - 140 MHz vibrations with 1 mW optical-threshold power and >2000 mechanical Q, constituting the first time that any microfluidic system is optomechanically actuated. Bridging between optomechanics and microfluidics will enable recently developed capillaries and on-chip bubbles to vibrate via optical excitation; and allow optomechanics with non-solid material phases including bio-analytes, sup...

  5. Temperature compensation of resonant cavities with a teflon post

    OpenAIRE

    1982-01-01

    The negative temperature coefficient of E for teflon is used to compensate the frequency drift of a metal cavity due to thermal expansion. An experimental X-band transmission resonator was compensated in this way with a 10 mm teflon post. The results are considered of great interest for the compensation of waveguide millimiter wave oscillators. Peer Reviewed

  6. Hybrid III-V/SOI Resonant Cavity Photodetector

    DEFF Research Database (Denmark)

    Learkthanakhachon, Supannee; Taghizadeh, Alireza; Park, Gyeong Cheol;

    2016-01-01

    A hybrid III-V/SOI resonant cavity photo detector has been demonstrated, which comprises an InP grating reflectorand a Si grating reflector. It can selectively detects an incident light with 1.54-µm wavelength and TM polarization....

  7. Scalable high-precision tuning of photonic resonators by resonant cavity-enhanced photoelectrochemical etching

    Science.gov (United States)

    Gil-Santos, Eduardo; Baker, Christopher; Lemaître, Aristide; Gomez, Carmen; Leo, Giuseppe; Favero, Ivan

    2017-01-01

    Photonic lattices of mutually interacting indistinguishable cavities represent a cornerstone of collective phenomena in optics and could become important in advanced sensing or communication devices. The disorder induced by fabrication technologies has so far hindered the development of such resonant cavity architectures, while post-fabrication tuning methods have been limited by complexity and poor scalability. Here we present a new simple and scalable tuning method for ensembles of microphotonic and nanophotonic resonators, which enables their permanent collective spectral alignment. The method introduces an approach of cavity-enhanced photoelectrochemical etching in a fluid, a resonant process triggered by sub-bandgap light that allows for high selectivity and precision. The technique is presented on a gallium arsenide nanophotonic platform and illustrated by finely tuning one, two and up to five resonators. It opens the way to applications requiring large networks of identical resonators and their spectral referencing to external etalons.

  8. High-Q 3D coaxial resonators for cavity QED

    Science.gov (United States)

    Yoon, Taekwan; Owens, John C.; Naik, Ravi; Lachapelle, Aman; Ma, Ruichao; Simon, Jonathan; Schuster, David I.

    Three-dimensional microwave resonators provide an alternative approach to transmission-line resonators used in most current circuit QED experiments. Their large mode volume greatly reduces the surface dielectric losses that limits the coherence of superconducting circuits, and the well-isolated and controlled cavity modes further suppress coupling to the environment. In this work, we focus on unibody 3D coaxial cavities which are only evanescently coupled and free from losses due to metal-metal interfaces, allowing us to reach extremely high quality-factors. We achieve quality-factor of up to 170 million using 4N6 Aluminum at superconducting temperatures, corresponding to an energy ringdown time of ~4ms. We extend our methods to other materials including Niobium, NbTi, and copper coated with Tin-Lead solder. These cavities can be further explored to study their properties under magnetic field or upon coupling to superconducting Josephson junction qubits, e.g. 3D transmon qubits. Such 3D cavity QED system can be used for quantum information applications, or quantum simulation in coupled cavity arrays.

  9. Electron Plasmas Cooled by Cyclotron-Cavity Resonance

    CERN Document Server

    Povilus, A P; Evans, L T; Evetts, N; Fajans, J; Hardy, W N; Hunter, E D; Martens, I; Robicheaux, F; Shanman, S; So, C; Wang, X; Wurtele, J S

    2016-01-01

    We observe that high-Q electromagnetic cavity resonances increase the cyclotron cooling rate of pure electron plasmas held in a Penning-Malmberg trap when the electron cyclotron frequency, controlled by tuning the magnetic field, matches the frequency of standing wave modes in the cavity. For certain modes and trapping configurations, this can increase the cooling rate by factors of ten or more. In this paper, we investigate the variation of the cooling rate and equilibrium plasma temperatures over a wide range of parameters, including the plasma density, plasma position, electron number, and magnetic field.

  10. Observation of generalized optomechanical coupling and cooling on cavity resonance

    CERN Document Server

    Sawadsky, Andreas; Nia, Ramon Moghadas; Tarabrin, Sergey P; Khalili, Farid Ya; Hammerer, Klemens; Schnabel, Roman

    2014-01-01

    Optomechanical coupling between a light field and the motion of a cavity mirror via radiation pressure plays an important role for the exploration of macroscopic quantum physics and for the detection of gravitational waves (GWs). It has been used to cool mechanical oscillators into their quantum ground states and has been considered to boost the sensitivity of GW detectors, e.g. via the optical spring effect. Here, we present the experimental characterization of generalized, that is, dispersive and dissipative optomechanical coupling, with a macroscopic (1.5mm)^2-sized silicon nitride (SiN) membrane in a cavity-enhanced Michelson-type interferometer. We report for the first time strong optomechanical cooling based on dissipative coupling, even on cavity resonance, in excellent agreement with theory. Our result will allow for new experimental regimes in macroscopic quantum physics and GW detection.

  11. Continuous ammonia monitor using a Stark microwave cavity resonator.

    Science.gov (United States)

    Uehara, H; Ijuuin, Y; Morino, Y; Kamidate, T; Nakamura, A; Imai, H

    1980-03-01

    An ammonia monitor has been made by using a rectangular Stark microwave cavity tightly coupled through an iris to a Gunn oscillator. The Stark electrode installed inside the cavity is provided with a 100 kHz sinusoidal modulation voltage and a dc sweep voltage. The oscillation of the Gunn diode is tuned with the coupled Stark cavity to a frequency near a J,K=3,3 transition (23870.1 MHz) of ammonia. By fixing the Stark dc bias to a voltage which gives a peak intensity of the derivative output of the electric-resonance signal, ammonia is continuously monitored. An extremely good long-term stability is obtained. The noise level corresponds to 0.08 ppm of ammonia.

  12. Quasistatic Cavity Resonance for Ubiquitous Wireless Power Transfer

    Science.gov (United States)

    Shahmohammadi, Mohsen; Sample, Alanson P.

    2017-01-01

    Wireless power delivery has the potential to seamlessly power our electrical devices as easily as data is transmitted through the air. However, existing solutions are limited to near contact distances and do not provide the geometric freedom to enable automatic and un-aided charging. We introduce quasistatic cavity resonance (QSCR), which can enable purpose-built structures, such as cabinets, rooms, and warehouses, to generate quasistatic magnetic fields that safely deliver kilowatts of power to mobile receivers contained nearly anywhere within. A theoretical model of a quasistatic cavity resonator is derived, and field distributions along with power transfer efficiency are validated against measured results. An experimental demonstration shows that a 54 m3 QSCR room can deliver power to small coil receivers in nearly any position with 40% to 95% efficiency. Finally, a detailed safety analysis shows that up to 1900 watts can be transmitted to a coil receiver enabling safe and ubiquitous wireless power. PMID:28199321

  13. Quasistatic Cavity Resonance for Ubiquitous Wireless Power Transfer.

    Science.gov (United States)

    Chabalko, Matthew J; Shahmohammadi, Mohsen; Sample, Alanson P

    2017-01-01

    Wireless power delivery has the potential to seamlessly power our electrical devices as easily as data is transmitted through the air. However, existing solutions are limited to near contact distances and do not provide the geometric freedom to enable automatic and un-aided charging. We introduce quasistatic cavity resonance (QSCR), which can enable purpose-built structures, such as cabinets, rooms, and warehouses, to generate quasistatic magnetic fields that safely deliver kilowatts of power to mobile receivers contained nearly anywhere within. A theoretical model of a quasistatic cavity resonator is derived, and field distributions along with power transfer efficiency are validated against measured results. An experimental demonstration shows that a 54 m3 QSCR room can deliver power to small coil receivers in nearly any position with 40% to 95% efficiency. Finally, a detailed safety analysis shows that up to 1900 watts can be transmitted to a coil receiver enabling safe and ubiquitous wireless power.

  14. Resonance widths in open microwave cavities studied by harmonic inversion.

    Science.gov (United States)

    Kuhl, U; Höhmann, R; Main, J; Stöckmann, H-J

    2008-06-27

    From the measurement of a reflection spectrum of an open microwave cavity, the poles of the scattering matrix in the complex plane have been determined. The resonances have been extracted by means of the harmonic inversion method. By this, it became possible to resolve the resonances in a regime where the linewidths exceed the mean level spacing up to a factor of 10, a value inaccessible in experiments up to now. The obtained experimental distributions of linewidths were found to be in perfect agreement with predictions from random matrix theory when wall absorption and fluctuations caused by couplings to additional channels are considered.

  15. Resonance widths in open microwave cavities studied by harmonic inversion

    OpenAIRE

    Kuhl, U; Hoehmann, R.; Main, J.; Stoeckmann, H. -J.

    2007-01-01

    From the measurement of a reflection spectrum of an open microwave cavity the poles of the scattering matrix in the complex plane have been determined. The resonances have been extracted by means of the harmonic inversion method. By this it became possible to resolve the resonances in a regime where the line widths exceed the mean level spacing up to a factor of 10, a value inaccessible in experiments up to now. The obtained experimental distributions of line widths were found to be in perfec...

  16. Conditioning for the RF Resonant Cavities of the CYCIAE-100

    Institute of Scientific and Technical Information of China (English)

    YIN; Zhi-guo; JI; Bin; ZHAO; Zhen-lu; FU; Xiao-liang; LEI; Yu; WANG; Chuan; YANG; Jian-jun; WEI; Jun-yi; LI; Peng-zhan; LV; Yin-long; ZHANG; Tian-jue; GE; Tao; CAI; Hong-ru; PAN; Gao-feng; ZHU; Peng-fei; AN; Shi-zhong; XING; Jian-sheng; YIN; Meng; CAO; Lei; ZHANG; Su-ping; WEN; Li-peng; HOU; Shi-gang; WU; Long-cheng; LIU; Geng-shou; LI; Zhen-guo; CUI; Bai-yao; DONG; Huan-jun

    2013-01-01

    The CYCIAE-100 cyclotron developed by the BRIF project group had finished installation of its main equipments and parts in 2012.The field mapping of the main magnet has been done afterward.In Dec.13th,2012,the vacuum of the main chamber reached 4×10-7 mbar,conditioning for the RF resonant cavities were started shortly after.When the cyclotron is opened the interior surface is exposed to air and

  17. Hybrid circuit cavity quantum electrodynamics with a micromechanical resonator.

    Science.gov (United States)

    Pirkkalainen, J-M; Cho, S U; Li, Jian; Paraoanu, G S; Hakonen, P J; Sillanpää, M A

    2013-02-14

    Hybrid quantum systems with inherently distinct degrees of freedom have a key role in many physical phenomena. Well-known examples include cavity quantum electrodynamics, trapped ions, and electrons and phonons in the solid state. In those systems, strong coupling makes the constituents lose their individual character and form dressed states, which represent a collective form of dynamics. As well as having fundamental importance, hybrid systems also have practical applications, notably in the emerging field of quantum information control. A promising approach is to combine long-lived atomic states with the accessible electrical degrees of freedom in superconducting cavities and quantum bits (qubits). Here we integrate circuit cavity quantum electrodynamics with phonons. Apart from coupling to a microwave cavity, our superconducting transmon qubit, consisting of tunnel junctions and a capacitor, interacts with a phonon mode in a micromechanical resonator, and thus acts like an atom coupled to two different cavities. We measure the phonon Stark shift, as well as the splitting of the qubit spectral line into motional sidebands, which feature transitions between the dressed electromechanical states. In the time domain, we observe coherent conversion of qubit excitation to phonons as sideband Rabi oscillations. This is a model system with potential for a quantum interface, which may allow for storage of quantum information in long-lived phonon states, coupling to optical photons or for investigations of strongly coupled quantum systems near the classical limit.

  18. Linewidth broadening of a quantum dot coupled to an off-resonant cavity

    CERN Document Server

    Majumdar, Arka; Kim, Erik; Englund, Dirk; Kim, Hyochul; Petroff, Pierre; Vuckovic, Jelena

    2010-01-01

    We study the coupling between a photonic crystal cavity and an off-resonant quantum dot under resonant excitation of the cavity or the quantum dot. Linewidths of the quantum dot and the cavity as a function of the excitation laser power are measured. We show that the linewidth of the quantum dot, measured by observing the cavity emission, is significantly broadened compared to the theoretical estimate. This indicates additional incoherent coupling between the quantum dot and the cavity.

  19. Mid-Infrared Tunable Resonant Cavity Enhanced Detectors

    Directory of Open Access Journals (Sweden)

    Hans Zogg

    2008-09-01

    Full Text Available Mid-infrared detectors that are sensitive only in a tunable narrow spectral band are presented. They are based on the Resonant Cavity Enhanced Detector (RCED principle and employing a thin active region using IV-VI narrow gap semiconductor layers. A Fabry-Pérot cavity is formed by two mirrors. The active layer is grown onto one mirror, while the second mirror can be displaced. This changes the cavity length thus shifting the resonances where the detector is sensitive. Using electrostatically actuated MEMS micromirrors, a very compact tunable detector system has been fabricated. Mirror movements of more than 3 μm at 30V are obtained. With these mirrors, detectors with a wavelength tuning range of about 0.7 μm have been realized. Single detectors can be used in mid-infrared micro spectrometers, while a detector arrangement in an array makes it possible to realize Adaptive Focal Plane Arrays (AFPA.

  20. A study of nasal cavity volume by magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Tosa, Yasuyoshi (Showa Univ., Tokyo (Japan). School of Medicine)

    1992-04-01

    The nasal cavity volume in 69 healthy volunteers from 8 to 23 years old (17 males and 52 females) was studied using magnetic resonance imaging (MRI). Merits of MRI such as no radiation exposure, less artifact due to bone and air and measurement of intravascular blood flow; and demerits such as contraindication in users of heart pace-makers or magnetic clips, contraindication in people with claustrophobia and influence of environmental magnetic fields must be considered. A Magunetom M10 (Siemens), a superconduction device with 1.0 Tesla magnetic flux density was used. Enhanced patterns of T[sub 1], and pulse lines were photographed at 600 msec TR (repetition time) and 19 msec TE (echo time) using SE (spin echo) and short SE (spin echo), and 3 or 4 mm slices. Photographs were made of the piriform aperture, choana, superior-middle-inferior concha including the nasal meatus, the frontal sinus, maxillary sinus, cribriform plate, and upper surface of the palate. The line connecting the maximum depression point in the nasal root and the pontomedullary junction was selected by sagittal median section, because this corresponds well with the CM (canthomeatal) line which is useful in CT (computed tomography). The transverse section of the nasal cavity volume was traced by display console with an accessory MRI device and calculated by integration of the slice width. The increase of height and body weight neared a plateau at almost 16 years, whereas increase of nasal cavity volume continued until about 20 years. Pearson's coefficient of correlation and regression line were significant. There were no significant differences in these parameters between male and female groups. Comparatively strong correlation between nasal cavity volume, and age, height and body weight was statistically evident. (author).

  1. A Lamb wave source based on the resonant cavity of phononic-crystal plates.

    Science.gov (United States)

    Sun, Jia-Hong; Wu, Tsung-Tsong

    2009-01-01

    In this paper, we propose a Lamb wave source that is based on the resonant cavity of a phononic-crystal plate. The phononic-crystal plate is composed of tungsten cylinders that form square lattices in a silicon plate, and the resonant cavity is created by arranging defects inside the periodic structure. The dispersion, transmission, and displacement of Lamb waves are analyzed by the finite-difference time-domain (FDTD) method. The eigenmodes inside the cavities of the phononic-crystal plate are identified as resonant modes. The fundamental and higher order resonant modes, which vary with the length of cavities, are calculated. By exciting the specific resonant mode in an asymmetric cavity, the 232.40 MHz flexural Lamb wave has a magnified amplitude of 78 times larger than the normal one. Thus, the cavity on the tungsten/silicon phononic-crystal plate may serve as a source element in a microscale acoustic wave device.

  2. Multipacting Analysis for the Half-Wave Spoke Resonator Crab Cavity for LHC

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Lixin; Li, Zenghai; /SLAC

    2011-06-23

    A compact 400-MHz half-wave spoke resonator (HWSR) superconducting crab cavity is being developed for the LHC upgrade. The cavity shape and the LOM/HOM couplers for such a design have been optimized to meet the space and beam dynamics requirements, and satisfactory RF parameters have been obtained. As it is known that multipacting is an issue of concern in a superconducting cavity which may limit the achievable gradient. Thus it is important in the cavity RF design to eliminate the potential MP conditions to save time and cost of cavity development. In this paper, we present the multipacting analysis for the HWSR crab cavity using the Track3P code developed at SLAC, and to discuss means to mitigate potential multipacting barriers. Track3P was used to analyze potential MP in the cavity and the LOM, HOM and FPC couplers. No resonances were found in the LOM couplers and the coaxial beam pipe. Resonant trajectories were identified on various locations in cavity, HOM and FPC couplers. Most of the resonances are not at the peak SEY of Nb. Run-away resonances were identified in broader areas on the cavity end plate and in the HOM coupler. The enhancement counter for run-away resonances does not show significant MP. HOM coupler geometry will be optimized to minimize the high SEY resonance.

  3. New resonant cavity-enhanced absorber structures for mid-infrared detector application

    CERN Document Server

    Zohar, Moshe; Faraone, Lorenzo; Hava, Shlomo

    2012-01-01

    A new dielectric Fabry-Perot cavity was designed for a resonant enhancing optical absorption by a thin absorber layer embedded into the cavity. In this cavity, the front mirror is a subwavelength grating with $\\sim 100$% retroreflection. For a HgCdTe absorber in a matching cavity of the new type, the design is shown to meet the combined challenges of increasing the absorbing efficiency of the entire device up to $\\sim 100$% and reducing its size and overall complexity, compared to a conventional resonant cavity enhanced HgCdTe absorber, while maintaining a fairly good tolerance against the grating's fabrication errors.

  4. A Complex Frequency Method for A Loaded Resonant Cavity of Transmission Lines

    Institute of Scientific and Technical Information of China (English)

    LIANGChanghong; LILong; SUTao; FANShengcai

    2004-01-01

    A complex frequency method for analyzing a loaded resonant cavity of transmission lines is presented in this paper. A sub-resonance system theory is used to treat the various loaded transmission lines cavity more effectively. Some practice examples are given to illustrate the application and validity of the proposed approach in this paper.

  5. Fano resonances control and slow light with Bose-Einstein Condensate in a cavity setup

    CERN Document Server

    Akram, M Javed; Khan, M Miskeen; Saif, Farhan

    2015-01-01

    We theoretically investigate the probe field transmission in an optomechanical cavity setup with Bose-Einstein Condensate (BEC), where the standing wave that forms in the cavity results in an one-dimensional optical lattice potential. We report that in the presence of atom-atom interactions, the coupling of the cavity field with condensate (Bogoliubov mode), the cavity field fluctuations and the condensate fluctuations leads to the emergence of the tunable Fano resonances in the probe absorption spectrum. Within the experimental reach, based on analytical and numerical simulations, we find that the optomechanical system with BEC provides great flexibility to tune the Fano resonances, as the width of the resonance is controllable by the coupling field and additionally, with the atom-atom interaction. Moreover, Fano resonances are analyzed for the fluctuations of the cavity field and the fluctuations of the condensate with finite atomic two-body interaction, which shows an excellent compatibility with the origi...

  6. Preparation of W state in resonant bimodal cavity quantum electrodynamics

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A scheme is proposed for generating entangled W states with four cavity modes. In this scheme, we send a Ⅴ-type three-level atom through two identical two-mode cavities in succession. After the atom exits from the second cavity,the four cavity modes are prepared in the W state. On the other hand we can obtain three-atom W states by sending three Ⅴ-type three-level atoms through a two-mode cavity in turn. The present scheme does not require conditional measurement, and it is easily generalized to preparing 2n-mode W states and n-atom W states.

  7. Discovery of higher order modes in a cylindrical reentrant-ring cavity resonator

    CERN Document Server

    Fan, Y; Carvalho, N C; Floch, J-M Le; Shan, Q; Tobar, M E

    2013-01-01

    Rigorous analysis of the properties of resonant modes in a reentrant cavity structure comprising of a post and ring is undertaken and verified experimentally. In particular for the first time we show the existence of higher order reentrant cavity modes in such a structure. Results show this cavity has a better displacement sensitivity compared to the common fundamental mode in a reentrant cylindrical cavity with just a single post. Thus, this type of cavity has the potential to operate as a highly sensitive transducer for a variety of precision measurement applications.

  8. Sensitive temperature measurements based on Lorentzian and Fano resonance lineshapes of a silicon photonic crystal cavity

    Science.gov (United States)

    Zhao, Chenyang; Fang, Liang; Yuan, Qinchen; Gan, Xuetao; Zhao, Jianlin

    2016-10-01

    We report a high-performance photonic temperature sensor by exploiting a silicon photonic crystal (PC) cavity. Since the PC cavity's spectra are very sensitive to the refractive index change, we observe remarkable variations of its resonant wavelength and output power under varying temperature levels. In a PC cavity with Lorentzian resonance lineshape, the sensor exhibits a linear spectrum-sensitivity of 70 pm/°, and the power-variation presents a high sensitivity as 1.28 dB/°. In addition, the Fano resonance lineshape generated by the PC cavity has also been employed to measure the temperature, which shows improved power sensitivity as 2.94 dB/ °. The demonstrated PC cavity-based sensor offers great potentials for low-cost, high sensitivity homogeneous sensing in chip-integrated devices.

  9. Optical control of resonant light transmission for an atom-cavity system

    CERN Document Server

    Sharma, Arijit; Sawant, Rahul V; Sheikholeslami, G; Budker, D; Rangwala, S A

    2015-01-01

    We demonstrate the manipulation of transmitted light through an optical Fabry-Perot cavity, built around a spectroscopy cell containing enriched rubidium vapor. Light resonant with the $^{87}$Rb D$_{2}$ ($F=2/F=1$) $\\leftrightarrow F'$ manifold, is controlled by transverse intersection of the cavity mode by another resonant light beam. The cavity transmission can be suppressed or enhanced depending on the coupling of atomic states due to the intersecting beams. The extreme manifestation of cavity mode control is the precipitious destruction (negative logic switching) or buildup (positive logic switching) of the transmitted light intensity, on intersection of the transverse control beam with the cavity mode. Both the steady state and transient response are experimentally investigated. The mechanism behind the change in cavity transmission is discussed in brief.

  10. Detecting body cavity bombs with nuclear quadrupole resonance

    Science.gov (United States)

    Collins, Michael London

    Nuclear Quadrupole Resonance (NQR) is a technology with great potential for detecting hidden explosives. Past NQR research has studied the detection of land mines and bombs concealed within luggage and packages. This thesis focuses on an NQR application that has received less attention and little or no publicly available research: detecting body cavity bombs (BCBs). BCBs include explosives that have been ingested, inserted into orifices, or surgically implanted. BCBs present a threat to aviation and secure facilities. They are extremely difficult to detect with the technology currently employed at security checkpoints. To evaluate whether or not NQR can be used to detect BCBs, a computational model is developed to assess how the dielectric properties of biological tissue affect the radio frequency magnetic field employed in NQR (0.5-5MHz). The relative permittivity of some biological tissue is very high (over 1,000 at 1MHz), making it conceivable that there is a significant effect on the electromagnetic field. To study this effect, the low-frequency approximation known as the Darwin model is employed. First, the electromagnetic field of a coil is calculated in free space. Second, a dielectric object or set of objects is introduced, and the free-space electric field is modified to accommodate the dielectric object ensuring that the relevant boundary conditions are obeyed. Finally, the magnetic field associated with the corrected electric field is calculated. This corrected magnetic field is evaluated with an NQR simulation to estimate the impact of dielectric tissue on NQR measurements. The effect of dielectric tissue is shown to be small, thus obviating a potential barrier to BCB detection. The NQR model presented may assist those designing excitation and detection coils for NQR. Some general coil design considerations and strategies are discussed.

  11. Experimental studies on perturbed acoustic resonant spectroscopy by a small rock sample in a cylindrical cavity

    Institute of Scientific and Technical Information of China (English)

    CHEN Dehua; WANG Xiuming; CONG Jiansheng; XU Delong; SONG Yanjie; MA Shuilong

    2006-01-01

    A measurement system for acoustic resonant spectroscopy (ARS) is established,and the effects of resonant cavity geometry,inner perturbation samples and environmental temperature on the ARS are investigated.The ARSs of the small samples with various sizes and acoustic properties are measured.The results show that at the normal pressure,the resonant frequency decreases gradually with the increase of liquid temperature in the cylindrical cavity,while the resonant amplitude increases.At certain pressure and temperature,both the resonant frequency and the amplitude decrease greatly when there exist air bubbles inside the cavity fluid.The ARS is apparently affected by the sample porosity and the sample location in the resonant cavity.At the middle of the cavity,the resonant frequencies reach their maximum values for all of the measurement samples.The resonant frequencies of the porous rock samples are smaller than those of the compacted samples if other acoustic parameters are the same.As the sample is moved from the top to the middle of the cavity along its axis,the resonant amplitude increases gradually for the compacted rocks while decreases for the unconsolidated rocks.Furthermore,the resonant amplitude increases firstly and then decreases if the porosity of the rock sample is relatively small.In addition,through the comparisons between the experimental and theoretical results,it is found that the effects of the acoustic parameters and sizes of the samples and the size of the cylindrical cavity on the laboratory results agree well with the theoretical ones qualitatively.These results may provide basic reference for the experiment study of rock acoustic properties in a low frequency using ARS.

  12. Evolution of Gaussian beams and pulsed laser action in laser with unstable resonant cavities

    Energy Technology Data Exchange (ETDEWEB)

    Isaev, A.A.; Kazarian, M.A.; Petrash, G.G.; Rautian, S.G.; Shalagin, A.M.

    1975-06-01

    A recurrent formula is derived which describes the passage of a Gaussian beam through an unstable resonant cavity and through a periodic optical system. The changes in the position and in the beam neck at the mirror within an arbitrary unstable cavity are analyzed as a function of the beam's initial parameters and the number of passages in the cavity. The evolution of nonaxial Gaussian beams is studied, and a generalization of the Lagrange-Helmholtz theorem is proposed.

  13. Design of plasmonic photonic crystal resonant cavities for polarization sensitive infrared photodetectors

    Science.gov (United States)

    Rosenberg, Jessie; Shenoi, Rajeev V.; Krishna, Sanjay; Painter, Oskar

    2010-02-01

    We design a polarization-sensitive resonator for use in midinfrared photodetectors, utilizing a photonic crystal cavity and a single or double-metal plasmonic waveguide to achieve enhanced detector efficiency due to superior optical confinement within the active region. As the cavity is highly frequency and polarization-sensitive, this resonator structure could be used in chip-based infrared spectrometers and cameras that can distinguish among different materials and temperatures to a high degree of precision.

  14. Spectrally and temporally resolved resonance shifts of a photonic crystal cavity switch

    DEFF Research Database (Denmark)

    Hansen, Per Lunnemann; Yu, Yi; Mørk, Jesper

    2016-01-01

    We present experimental results of temporally and spectrally resolved transmission measurements of a photonic crystal cavity using two-color pump-probe technique. With a gated spectral measurement, we measure the resonance shift's dependence on pump power.......We present experimental results of temporally and spectrally resolved transmission measurements of a photonic crystal cavity using two-color pump-probe technique. With a gated spectral measurement, we measure the resonance shift's dependence on pump power....

  15. Perturbing open cavities: Anomalous resonance frequency shifts in a hybrid cavity-nanoantenna system

    CERN Document Server

    Ruesink, Freek; Hendrikx, Ruud; Koenderink, A Femius; Verhagen, Ewold

    2015-01-01

    The influence of a small perturbation on a cavity mode plays an important role in fields like optical sensing, cavity quantum electrodynamics and cavity optomechanics. Typically, the resulting cavity frequency shift directly relates to the polarizability of the perturbation. Here we demonstrate that particles perturbing a radiating cavity can induce strong frequency shifts that are opposite to, and even exceed, the effects based on the particles' polarizability. A full electrodynamic theory reveals that these anomalous results rely on a non-trivial phase relation between cavity and nanoparticle radiation, allowing back-action via the radiation continuum. In addition, an intuitive model based on coupled mode theory is presented that relates the phenomenon to retardation. Because of the ubiquity of dissipation, we expect these findings to benefit the understanding and engineering of a wide class of systems.

  16. Perturbing Open Cavities: Anomalous Resonance Frequency Shifts in a Hybrid Cavity-Nanoantenna System

    Science.gov (United States)

    Ruesink, Freek; Doeleman, Hugo M.; Hendrikx, Ruud; Koenderink, A. Femius; Verhagen, Ewold

    2015-11-01

    The influence of a small perturbation on a cavity mode plays an important role in fields like optical sensing, cavity quantum electrodynamics, and cavity optomechanics. Typically, the resulting cavity frequency shift directly relates to the polarizability of the perturbation. Here, we demonstrate that particles perturbing a radiating cavity can induce strong frequency shifts that are opposite to, and even exceed, the effects based on the particles' polarizability. A full electrodynamic theory reveals that these anomalous results rely on a nontrivial phase relation between cavity and nanoparticle radiation, allowing backaction via the radiation continuum. In addition, an intuitive model based on coupled mode theory is presented that relates the phenomenon to retardation. Because of the ubiquity of dissipation, we expect these findings to benefit the understanding and engineering of a wide class of systems.

  17. High-precision spectral tuning of micro and nanophotonic cavities by resonantly enhanced photoelectrochemical etching

    CERN Document Server

    Gil-Santos, Eduardo; Lemaitre, Aristide; Gomez, Carmen; Ducci, Sara; Leo, Giuseppe; Favero, Ivan

    2015-01-01

    We present a simple method to tune optical micro- and nanocavities with picometer precision in the resonant wavelength, corresponding to an effective sub atomic monolayer control of the cavity dimension. This is obtained through resonant photo-electrochemical etching, with in-situ monitoring of the optical spectrum. We employ this technique to spectrally align an ensemble of resonant cavities in a permanent manner, overcoming the dimension variability resulting from current nanofabrication techniques. In a device containing several resonators, each is individually addressed and tuned, with no optical quality factor degradation. The technique is general and opens the way to multiple applications, such as the straightforward fabrication of networks of identical coupled resonators, or the tuning of chip-based cavities to external references.

  18. Approximate Toffoli Gate Originated from a Single Resonant Interaction of Cavity Dissipation and Atomic Spontaneous Emission

    Institute of Scientific and Technical Information of China (English)

    GU Xiao-Yan; CHEN Chang-Yong; SUN Jian-Qiang

    2008-01-01

    We propose a potentially practical scheme to implement an approximate three-qubit Toffoli gate by a single resonant interaction in dissipative cavity QED in which the cavity mode decay and atomic spontaneous emission are considered. The scheme does not require two-qubit controlled-NOT gates but uses a three-qubit phase gate and two Hadamard gates, where the approximate phase gate can be implemented by only a single dissipative resonant interaction of atoms with the cavity mode. Discussions are made for the advantages and the experimental feasibility of our scheme.

  19. Implementation of n-qubit Deutsch-Jozsa algorithm using resonant interaction in cavity QED

    Institute of Scientific and Technical Information of China (English)

    Wang Hong-Fu; Zhang Shou

    2008-01-01

    We propose a scheme to implement the n-qubit Deutsch-Jozsa algorithm based on resonant interaction between the atoms and a single-mode cavity. In the scheme, the resonant transitions between two ground states and one excited state of an atom are changed alternately by adjusting the cavity frequency appropriately, and the operations required to complete the algorithm can be significantly simplified following the increment of the number of qubits. The implementation of the scheme in experiment would show the full power of quantum algorithm and would be significative and important for more complicated quantum algorithm in cavity quantum electrodynamics.

  20. Computation of high frequency fields in resonant cavities based on perturbation theory

    Energy Technology Data Exchange (ETDEWEB)

    Brackebusch, Korinna; Glock, Hans-Walter; Rienen, Ursula van [Universitaet Rostock (Germany). Institut fuer Allgemeine Elektrotechnik

    2012-07-01

    The eigenmodes of an accelerator cavity are essential for the determination of its performance characteristics, comprising resonant frequencies and field distributions inside the cavity. Apart from the material properties the eigenmodes depend on the cavity geometry. Due to manufacturing tolerances and operational demands deviations of the actual cavity shape from the desired one are inevitable. Any geometry perturbation results in a shift of the resonant frequencies and modified field distributions. Slater's theorem offers an efficient way to compute the changed resonant frequencies, however, not the changed fields. In this work, we will analyse a generalisation of Slater's theorem proposed in literature. The method enables the computation of the resonant frequencies and the field distributions of a slightly perturbed cavity by using a set of eigenmodes of the unperturbed cavity. We evaluate the practicability of the method by applying it to cavity geometries for which the eigenmodes are analytically known, ascertain the effort of reasonable computation results and describe the limitations of the method.

  1. Mode-locked pulse oscillation of a self-resonating enhancement optical cavity

    CERN Document Server

    Hosaka, Yuji; Kosuge, Atsushi; Omori, Tsunehiko; Sakaue, Kazuyuki; Takahashi, Tohru; Uesugi, Yuuki; Urakawa, Junji; Washio, Masakazu

    2016-01-01

    A power enhancement optical cavity is a compelling means of realizing a pulsed laser with a high peak power and a high repetition frequency, which is not feasible by using a simple amplifier scheme. However, a precise feedback system is necessary for maintaining the narrow resonance condition of the optical cavity, and has become a major technical issue in developing such cavities. We developed a new approach that does not require any active feedback system, by placing the cavity in the outer loop of a laser amplifier. We report on the first demonstration of a mode-locked pulse oscillation using the new system.

  2. Design of an efficient terahertz source using triply resonant nonlinear photonic crystal cavities.

    Science.gov (United States)

    Burgess, Ian B; Zhang, Yinan; McCutcheon, Murray W; Rodriguez, Alejandro W; Bravo-Abad, Jorge; Johnson, Steven G; Loncar, Marko

    2009-10-26

    We propose a scheme for efficient cavity-enhanced nonlinear THz generation via difference-frequency generation (DFG) processes using a triply resonant system based on photonic crystal cavities. We show that high nonlinear overlap can be achieved by coupling a THz cavity to a doubly-resonant, dual-polarization near-infrared (e.g. telecom band) photonic-crystal nanobeam cavity, allowing the mixing of three mutually orthogonal fundamental cavity modes through a chi((2)) nonlinearity. We demonstrate through coupled-mode theory that complete depletion of the pump frequency - i.e., quantum-limited conversion - is possible. We show that the output power at the point of optimal total conversion efficiency is adjustable by varying the mode quality (Q) factors.

  3. Optical bistability enabled control of resonant light transmission for an atom-cavity system

    CERN Document Server

    Sawant, Rahul

    2015-01-01

    The control of light transmission through a Fabry-Perot cavity containing atoms is theoretically investigated, when the cavity mode beam and an intersecting control beam are both close to specific atomic resonances. A four-level atomic system is considered and its interaction with the cavity mode is studied by solving for the time dependent cavity field and atomic state populations. The conditions for optical bistability of the atom-cavity system are obtained in steady state limit. For an ensemble of atoms in the cavity mode, the response of the intra-cavity light intensity to the intersecting resonant beam is understood for stationary atoms (closed system) and non-static atoms (open system). The open system is modelled by adjusting the atomic state populations to represent the exchange of atoms in the cavity mode, with the thermal environment. The solutions to the model are used to qualitatively explain the observed steady state and transient behaviour of the light in the cavity mode, in Sharma et. al. [1]. ...

  4. Study of low work function materials for hot cavity resonance ionization laser ion sources

    CERN Document Server

    Schwellnus, F; Crepieux, B; Fedosseev, V N; Marsh, B A; Mattolat, Ch; Menna, M; Österdahl, F K; Raeder, S; Stora, T; Wendta, K

    2009-01-01

    The selectivity of a hot cavity resonance ionization laser ion source (RILIS) is most often limited by contributions from competing surface ionization of the hot walls of the ionization cavity. In this article we present investigations on the properties of designated high temperature, low work function materials regarding their performance and suitability as cavity material for RILIS. Tungsten test cavities, impregnated with a mixture of barium oxide and strontium oxide (BaOSrO on W), or alternatively gadolinium hexaboride (GdB6) were studied in comparison to a standard tungsten RILIS cavity as being routinely used for hot cavity laser ionization at ISOLDE. Measurement campaigns took place at the off-line mass separators at ISOLDE/CERN, Geneva and RISIKO/University of Mainz.

  5. Study of Low Work Function Materials for Hot Cavity Resonance Ionization Laser Ion Sources

    CERN Document Server

    Catherall, R; Fedosseev, V; Marsh, B; Mattolat, C; Menna, Mariano; Österdahl, F; Raeder, S; Schwellnus, F; Stora, T; Wendt, K; CERN. Geneva. AB Department

    2008-01-01

    The selectivity of a hot cavity resonance ionization laser ion source (RILIS) is most often limited by contributions from competing surface ionization on the hot walls of the ionization cavity. In this article we present investigations on the properties of designated high-temperature, low-work function materials regarding their performance and suitability as cavity material for RILIS. Tungsten test cavities, impregnated with a mixture of barium oxide and strontium oxide (BaOSrO on W), or alternatively gadolinium hexaboride (GdB6) were studied in comparison to a standard tungsten RILIS cavity as being routinely used for hot cavity laser ionization at ISOLDE. Measurement campaigns took place at the off-line mass separators at ISOLDE / CERN, Geneva and RISIKO / University of Mainz.

  6. Gain enhanced Fano resonance in a coupled photonic crystal cavity-waveguide structure

    Science.gov (United States)

    Zhao, Yanhui; Qian, Chenjiang; Qiu, Kangsheng; Tang, Jing; Sun, Yue; Jin, Kuijuan; Xu, Xiulai

    2016-01-01

    Systems with coupled cavities and waveguides have been demonstrated as optical switches and optical sensors. To optimize the functionalities of these optical devices, Fano resonance with asymmetric and steep spectral line shape has been used. We theoretically propose a coupled photonic crystal cavity-waveguide structure to achieve Fano resonance by placing partially reflecting elements in waveguide. To enhance Fano resonance, optical gain material is introduced into the cavity. As the gain increases, the transmission line shape becomes steepened and the transmissivity can be six times enhanced, giving a large contrast by a small frequency shift. It is prospected that the gain enhanced Fano resonance is very useful for optical switches and optical sensors. PMID:27640809

  7. Silicon reflectors for external cavity lasers based on ring resonators

    Science.gov (United States)

    Wang, Chao; Li, Xia; Jin, Hao; Yu, Hui; Yang, Jianyi; Jiang, Xiaoqing

    2017-01-01

    We propose and experimentally investigate types of silicon ring reflectors on Silicon-On-Insulator (SOI) platform. These reflectors are used for realizing the silicon hybrid external cavity lasers. A suspended edge coupler is used to connect the reflective semiconductor optical amplifier (RSOA) chip and the reflectors. The properties of the reflectors and the hybrid external cavity lasers with these reflectors are illustrated. The experimental results show that all of those reflectors have a high reflectivity and the highest reflectivity can up to be 95%. The lowest insertion loss can be as low as 0.4 dB. The output power of the hybrid external cavity lasers with these reflectors can reach mW magnitude and the highest output power is 6.1 mW. Over 30 dB side mode suppression ratio is obtained.

  8. Optical-bistability-enabled control of resonant light transmission for an atom-cavity system

    Science.gov (United States)

    Sawant, Rahul; Rangwala, S. A.

    2016-02-01

    The control of light transmission through a standing-wave Fabry-Pérot cavity containing atoms is theoretically and numerically investigated, when the cavity mode beam and an intersecting control beam are both close to specific atomic resonances. A four-level atomic system is considered and its interaction with the cavity mode is studied by solving for the cavity field and atomic state populations. The conditions for optical bistability of the atom-cavity system are obtained. The response of the intracavity intensity to an intersecting beam on atomic resonance is understood in the presence of stationary atoms (closed system) and nonstatic atoms (open system) in the cavity. The nonstatic system of atoms is modelled by adjusting the atomic state populations to represent the exchange of atoms in the cavity mode, which corresponds to a thermal environment where atoms are moving in and out of the cavity mode volume. The control behavior with three- and two-level atomic systems is also studied, and the rich physics arising out of these systems for closed and open atomic systems is discussed. The solutions to the models are used to interpret the steady-state and transient behavior observed by Sharma et al. [Phys. Rev. A 91, 043824 (2015)], 10.1103/PhysRevA.91.043824.

  9. Towards achieving strong coupling in three-dimensional-cavity with solid state spin resonance

    Science.gov (United States)

    Le Floch, J.-M.; Delhote, N.; Aubourg, M.; Madrangeas, V.; Cros, D.; Castelletto, S.; Tobar, M. E.

    2016-04-01

    We investigate the microwave magnetic field confinement in several microwave three-dimensional (3D)-cavities, using a 3D finite-element analysis to determine the best design and achieve a strong coupling between microwave resonant cavity photons and solid state spins. Specifically, we design cavities for achieving strong coupling of electromagnetic modes with an ensemble of nitrogen vacancy (NV) defects in diamond. We report here a novel and practical cavity design with a magnetic filling factor of up to 4 times (2 times higher collective coupling) than previously achieved using one-dimensional superconducting cavities with a small mode volume. In addition, we show that by using a double-split resonator cavity, it is possible to achieve up to 200 times better cooperative factor than the currently demonstrated with NV in diamond. These designs open up further opportunities for studying strong and ultra-strong coupling effects on spins in solids using alternative systems with a wider range of design parameters. The strong coupling of paramagnetic spin defects with a photonic cavity is used in quantum computer architecture, to interface electrons spins with photons, facilitating their read-out and processing of quantum information. To achieve this, the combination of collective coupling of spins and cavity mode is more feasible and offers a promising method. This is a relevant milestone to develop advanced quantum technology and to test fundamental physics principles.

  10. The cavity resonator design: stochastic optimization of the transmission line method

    Science.gov (United States)

    Jurečka, Stanislav; Müllerová, Jarmila; Dado, Milan

    2012-02-01

    Stable cavity resonators provide an ideal solution for high quality applications in telecommunications, laser sources, sensors, oscillators and filters, instrumentation and other large area of applications. For the determination of the electromagnetic field (EMF) properties in a cavity resonator several numerical methods are widely used. In our approach we used the transmission line modeling method (TLM). It is a wide-band time-domain numerical method suitable for solution of the electromagnetic field in a studied region. TLM method is based on the isomorphism between the theory of passive electrical network and the wave equation describing the properties of the EMF. TLM method offers two important advantages over the time-domain techniques such as the finite-difference time domain methods. The electric and magnetic field are resolved synchronously in time and space and TLM in implicitly stable method due to the mapping to electrical circuits. The EMF in the rectangular cavity is in our approach determined by the TLM method and the frequency spectrum is computed by the Fourier transform of the time signal. The theoretical model of the cavity EMF power spectral density function contains information about the geometrical configuration of the resonator. In our work we use the genetic algorithm for the determination of optimal dimensions of the cavity resonator expected for the proposed output resonant frequency. The stochastic modification of the theoretical model parameters is controlled by the genetic operators of mutation, crossover and selection, leading to overall improvement of the theoretical model estimation during the optimization process.

  11. Solution of Cavity Resonance and Waveguide Scattering Problems Using the Eigenmode Projection Technique

    CERN Document Server

    Nasr, Mamdouh H; Eshrah, Islam A; Abuelfadl, Tamer M

    2016-01-01

    An eigenmode projection technique (EPT) is developed and employed to solve problems of electromagnetic resonance in closed cavities and scattering from discontinuities in guided-wave structures. The EPT invokes the eigenmodes of a canonical predefined cavity in the solution procedure and uses the expansion of these eigenmodes to solve Maxwell's equations, in conjunction with a convenient choice of port boundary conditions. For closed cavities, resonance frequencies of arbitrary-shaped cavities are accurately determined with a robust and efficient separation method of spurious modes. For waveguide scattering problems, the EPT is combined with the generalized scattering matrix approach to solve problems involving waveguide discontinuities with arbitrary dielectric profiles. Convergence studies show stable solutions for a relatively small number of expansion modes, and the proposed method shows great robustness over conventional solvers in analyzing electromagnetic problems with inhomogeneous materials.

  12. Teleportation of two-atom entangled state in resonant cavity quantum electrodynamics

    Institute of Scientific and Technical Information of China (English)

    Yang Zhen-Biao

    2007-01-01

    An alternative scheme is presented for teleportation of a two-atom entangled state in cavity quantum electrodynamics (QED). It is based on the resonant atom-cavity field interaction. In the scheme, only one cavity is involved, and the number of the atoms needed to be detected is decreased compared with the previous scheme. Since the resonant atom-cavity field interaction greatly reduces the interaction time, the decoherence effect can be effectively suppressed during the teleportation process. The experimental feasibility of the scheme is discussed. The scheme can easily be generalized to the teleportation of N-atom Greeninger-Horne-Zeilinger (GHZ) entangled states. The number of atoms needed to be detected does not increase as the number of the atoms in the GHZ state increases.

  13. Resonance suppression and electromagnetic shielding effectiveness improvement of an apertured rectangular cavity by using wall losses

    Institute of Scientific and Technical Information of China (English)

    Jiao Chong-Qing; Zhu Hong-Zhao

    2013-01-01

    The cavity-mode resonance effect could result in significant degradation of the shielding effectiveness (SE) of a shielding enclosure around its resonance frequencies.In this paper,the influence of coated wall loss on the suppression of the resonance effect is investigated.For this purpose,an equivalent circuit model is employed to analyze the SE of an apertured rectangular cavity coated with an inside layer of resistive material.The model is developed by extending Robinson's equivalent circuit model through incorporating the effect of the wall loss into both the propagation constant and the characteristic impedance of the waveguide.Calculation results show that the wall loss could lead to great improvement on the SE for frequencies near the resonance but almost no effect on the SE for frequencies far away from the resonance.

  14. Near-field coupling and resonant cavity modes in plasmonic nanorod metamaterials.

    Science.gov (United States)

    Song, Haojie; Zhang, Junxi; Fei, Guangtao; Wang, Junfeng; Jiang, Kang; Wang, Pei; Lu, Yonghua; Iorsh, Ivan; Xu, Wei; Jia, Junhui; Zhang, Lide; Kivshar, Yuri S; Zhang, Lin

    2016-10-14

    Plasmonic resonant cavities are capable of confining light at the nanoscale, resulting in both enhanced local electromagnetic fields and lower mode volumes. However, conventional plasmonic resonant cavities possess large Ohmic losses at metal-dielectric interfaces. Plasmonic near-field coupling plays a key role in a design of photonic components based on the resonant cavities because of the possibility to reduce losses. Here, we study the plasmonic near-field coupling in the silver nanorod metamaterials treated as resonant nanostructured optical cavities. Reflectance measurements reveal the existence of multiple resonance modes of the nanorod metamaterials, which is consistent with our theoretical analysis. Furthermore, our numerical simulations show that the electric field at the longitudinal resonances forms standing waves in the nanocavities due to the near-field coupling between the adjacent nanorods, and a new hybrid mode emerges due to a coupling between nanorods and a gold-film substrate. We demonstrate that this coupling can be controlled by changing the gap between the silver nanorod array and gold substrate.

  15. Near-field coupling and resonant cavity modes in plasmonic nanorod metamaterials

    Science.gov (United States)

    Song, Haojie; Zhang, Junxi; Fei, Guangtao; Wang, Junfeng; Jiang, Kang; Wang, Pei; Lu, Yonghua; Iorsh, Ivan; Xu, Wei; Jia, Junhui; Zhang, Lide; Kivshar, Yuri S.; Zhang, Lin

    2016-10-01

    Plasmonic resonant cavities are capable of confining light at the nanoscale, resulting in both enhanced local electromagnetic fields and lower mode volumes. However, conventional plasmonic resonant cavities possess large Ohmic losses at metal-dielectric interfaces. Plasmonic near-field coupling plays a key role in a design of photonic components based on the resonant cavities because of the possibility to reduce losses. Here, we study the plasmonic near-field coupling in the silver nanorod metamaterials treated as resonant nanostructured optical cavities. Reflectance measurements reveal the existence of multiple resonance modes of the nanorod metamaterials, which is consistent with our theoretical analysis. Furthermore, our numerical simulations show that the electric field at the longitudinal resonances forms standing waves in the nanocavities due to the near-field coupling between the adjacent nanorods, and a new hybrid mode emerges due to a coupling between nanorods and a gold-film substrate. We demonstrate that this coupling can be controlled by changing the gap between the silver nanorod array and gold substrate.

  16. Cavity optomechanics nano- and micromechanical resonators interacting with light

    CERN Document Server

    Kippenberg, Tobias; Marquardt, Florian

    2014-01-01

    During the last few years cavity-optomechanics has emerged as a new field of research. This highly interdisciplinary field studies the interaction between micro- and nanomechanical systems and light. Possible applications range from novel high-bandwidth mechanical sensing devices through the generation of squeezed optical or mechanical states to even tests of quantum theory itself. This is one of the first books in this relatively young field. it is aimed at scientists, engineers, and students who want to obtain a concise introduction to the state of the art in the field of cavity optomechanics. It is valuable to researchers in nanoscience, quantum optics, quantum information, gravitational wave detection and other cutting edge fields. Possible applications include biological sensing, frequency comb applications, silicon photonics etc. The technical content will be accessible to those who have familiarity with basic undergraduate physics.

  17. Two-Dimensional Cavity Resonant Modes of Si Based Bragg Reflection Ridge Waveguide

    Institute of Scientific and Technical Information of China (English)

    CHEN San; Lu Hong-Yan; CHEN Kun-Ji; XU Jun; MA Zhong-Yuan; LI Wei; HUANG Xin-Fan

    2011-01-01

    @@ Si-based ridge-waveguides with Bragg reflectors are fabricated based on our method.Three resonant peaks could be obviously identified from the photoluminescence spectra, and field patterns of these resonant peaks, simulated by the finite difference time domain (FDTD) method, confirm that these peaks originate from cavity resonances.The resonant wavelengths and spatial angular distribution are given by the resonant models, which agree well with the experimental data.Experimentally, a simple method is proposed to testify the experimental and theoretical results.Such devices based on Bragg reflectors may have potential applications in light-emitting diodes, lasers and integrated photonic circuits.%Si-based ridge-waveguides with Bragg reflectors are fabricated based on our method. Three resonant peaks could be obviously identified from the photoluminescence spectra, and field patterns of these resonant peaks, simulated by the finite difference time domain (FDTD) method, confirm that these peaks originate from cavity resonances. The resonant wavelengths and spatial angular distribution are given by the resonant models, which agree well with the experimental data. Experimentally, a simple method is proposed to testify the experimental and theoretical results. Such devices based on Bragg reflectors may have potential applications in light-emitting diodes, lasers and integrated photonic circuits.

  18. Excitation and tuning of Fano-like cavity plasmon resonances in dielectric-metal core-shell resonators

    Science.gov (United States)

    Gu, Ping; Wan, Mingjie; Wu, Wenyang; Chen, Zhuo; Wang, Zhenlin

    2016-05-01

    Fano resonances have been realized in plasmonic systems and have found intriguing applications, in which, however, precisely controlled symmetry breaking or particular arrangement of multiple constituents is usually involved. Although simple core-shell type architectures composed of a spherical dielectric core and a concentric metallic shell layer have been proposed as good candidates that support inherent Fano resonances, these theoretical predictions have rarely seen any detailed experimental investigation. Here, we report on the experimental investigation of the magnetic and electric-based multipolar plasmonic Fano resonances in the dielectric-metal core-shell resonators that are formed by wrapping a nearly perfect metal shell layer around a dielectric sphere. We demonstrate that these Fano resonances originate from the interference between the Mie cavity and sphere plasmon resonances. Moreover, we present that the variation on either the dielectric core size or core refractive index allows for easily tuning the observed Fano resonances over a wide spectral range. Our findings are supported by excellent agreement with analytical calculations, and offer unprecedented opportunities for realizing ultrasensitive bio-sensors, lasing and nonlinear optical devices.Fano resonances have been realized in plasmonic systems and have found intriguing applications, in which, however, precisely controlled symmetry breaking or particular arrangement of multiple constituents is usually involved. Although simple core-shell type architectures composed of a spherical dielectric core and a concentric metallic shell layer have been proposed as good candidates that support inherent Fano resonances, these theoretical predictions have rarely seen any detailed experimental investigation. Here, we report on the experimental investigation of the magnetic and electric-based multipolar plasmonic Fano resonances in the dielectric-metal core-shell resonators that are formed by wrapping a

  19. Exploring the distinction between experimental resonant modes and theoretical eigenmodes: From vibrating plates to laser cavities

    Science.gov (United States)

    Tuan, P. H.; Wen, C. P.; Yu, Y. T.; Liang, H. C.; Huang, K. F.; Chen, Y. F.

    2014-02-01

    Experimentally resonant modes are commonly presumed to correspond to eigenmodes in the same bounded domain. However, the one-to-one correspondence between theoretical eigenmodes and experimental observations is never reached. Theoretically, eigenmodes in numerous classical and quantum systems are the solutions of the homogeneous Helmholtz equation, whereas resonant modes should be solved from the inhomogeneous Helmholtz equation. In the present paper we employ the eigenmode expansion method to derive the wave functions for manifesting the distinction between eigenmodes and resonant modes. The derived wave functions are successfully used to reconstruct a variety of experimental results including Chladni figures generated from the vibrating plate, resonant patterns excited from microwave cavities, and lasing modes emitted from the vertical cavity.

  20. Electrical conductivity of Jupiter's shallow interior and the formation of a resonant of a resonant planetary-ionospheric cavity

    Science.gov (United States)

    Sentman, D. D.

    1990-01-01

    The present consideration of hydrogenic atmospheric reactions on Jupiter, to a depth of 4000 km, notes the primary ion constituents at these depths to be both positive and negative ions of molecular hydrogen contributing less than 20 percent to total electrical conductivity by free electrons. An electrical surface defined by the boundary beneath which the interior is electrically conducting exists at depths which vary according to EM wave frequency, from 1100 km for 1 mHz to 3000 for 1 MHz. The presence of a lower electrical boundary within the shallow interior suggests that a planetary-ionosphere resonant cavity analogous to the earth-ionosphere cavity may exist.

  1. Resonant-frequency discharge in a multi-cell radio frequency cavity

    Energy Technology Data Exchange (ETDEWEB)

    Popovic, S; Upadhyay, J; Mammosser, J; Nikolic, M; Vuskovic, L

    2014-11-07

    We are reporting experimental results on microwave discharge operating at resonant frequency in a multi-cell radio frequency (RF) accelerator cavity. Although the discharge operated at room temperature, the setup was constructed so that it could be used for plasma generation and processing in fully assembled active superconducting radio-frequency (SRF) cryomodule (in situ operation). This discharge offers an efficient mechanism for removal of a variety of contaminants, organic or oxide layers, and residual particulates from the interior surface of RF cavities through the interaction of plasma-generated radicals with the cavity walls. We describe resonant RF breakdown conditions and address the problems related to generation and sustaining the multi-cell cavity plasma, which are breakdown and resonant detuning. We have determined breakdown conditions in the cavity, which was acting as a plasma vessel with distorted cylindrical geometry. We discuss the spectroscopic data taken during plasma removal of contaminants and use them to evaluate plasma parameters, characterize the process, and estimate the volatile contaminant product removal.

  2. Properties of Optical Resonant Modes in Ⅲ-Nitride Semiconductor Micro-Cone Cavities

    Institute of Scientific and Technical Information of China (English)

    DAI Lun; ZHANG Bei; LIN Jing-Yu; JIANG Hong-Xing

    2001-01-01

    Arrays of Ⅲ-nitride semiconductor micro-cone cavities with a base diameter of 3.3μm were fabricated by ion beam etching. The micro-cones consisted of 58 nm thick multiple quantum wells of ln0.22Ga0.78N/In0.06Ga0.94N as well as a 1.5μm thick epilayer of GaN. Optical resonant modes from a single micro-cone could be clearly observed in the photoluminescence spectra at temperatures up to 200K under a pumping power density two orders of magnitude lower than that for the Ⅲ-nitride semiconductor micro-disk or micro-ring cavity. Using a novel optical ray tracing method, we have figured out four main types of optical resonant cavities inside the three-dimensional micro-cone, including two Fabry-Perot (F-P) mode types as well as two Whispering Gallery mode types. The three corresponding mode spacings among the four agree perfectly with the experimental results. The advantages of this new class of micro-cavity over the other micro-cavities are discussed. These findings are expected to have an impact on the design of the ultraviolet/blue micro-cavity laser diodes.

  3. Noise reduction in double-panel structures by cavity and panel resonance control

    NARCIS (Netherlands)

    Ho, J.-H.; Berkhoff, A.P

    2011-01-01

    This paper presents an investigation of the cavity and the panel resonance control in a double‐panel structure. The double‐panel structure, which consists of two panels with air in the gap, is widely adopted in many applications such as aerospace due to its light weight and effective transmission‐lo

  4. Cavitation tunnel analysis of radiated sound from the resonance of a propeller tip vortex cavity

    NARCIS (Netherlands)

    Pennings, P.C.; Westerweel, J.; Van Terwisga, T.J.C.

    2016-01-01

    The goal of this study is to test the hypothesis that the resonance of a tip vortex cavity is responsible for high-amplitude broadband pressure-fluctuations, typically between 40 and 70 Hz,Hz, for a full scale propeller. This is achieved with a model propeller in a cavitation tunnel. Simultaneous hi

  5. Laser and cavity cooling of a mechanical resonator with a nitrogen-vacancy center in diamond

    Science.gov (United States)

    Giannelli, Luigi; Betzholz, Ralf; Kreiner, Laura; Bienert, Marc; Morigi, Giovanna

    2016-11-01

    We theoretically analyze the cooling dynamics of a high-Q mode of a mechanical resonator, when the structure is also an optical cavity and is coupled with a nitrogen-vacancy (NV) center. The NV center is driven by a laser and interacts with the cavity photon field and with the strain field of the mechanical oscillator, while radiation pressure couples the mechanical resonator and cavity field. Starting from the full master equation we derive the rate equation for the mechanical resonator's motion, whose coefficients depend on the system parameters and on the noise sources. We then determine the cooling regime, the cooling rate, the asymptotic temperatures, and the spectrum of resonance fluorescence for experimentally relevant parameter regimes. For these parameters, we consider an electronic transition, whose linewidth allows one to perform sideband cooling, and show that the addition of an optical cavity in general does not improve the cooling efficiency. We further show that pure dephasing of the NV center's electronic transitions can lead to an improvement of the cooling efficiency.

  6. Normalization of quasinormal modes in leaky optical cavities and plasmonic resonators

    CERN Document Server

    Kristensen, Philip Trøst; Hughes, Stephen

    2015-01-01

    We discuss three formally different formulas for normalization of quasinormal modes currently in use for modeling optical cavities and plasmonic resonators and show that they are complementary and provide the same result. Regardless of the formula used for normalization, one can use the norm to define an effective mode volume for use in Purcell factor calculations.

  7. Tunable Resonant-Cavity-Enhanced Photodetector with Double High-Index-Contrast Grating Mirrors

    DEFF Research Database (Denmark)

    Learkthanakhachon, Supannee; Yvind, Kresten; Chung, Il-Sug

    2013-01-01

    In this paper, we propose a broadband-tunable resonant-cavity-enhanced photodetector (RCE-PD) structure with double high-index-contrast grating (HCG) mirrors and numerically investigate its characteristics. The detector is designed to operate at 1550-nm wavelength. The detector structure consists...

  8. Development of 400- to 450-MHz RFQ resonator-cavity mechanical designs

    Energy Technology Data Exchange (ETDEWEB)

    Hansborough, L.D.

    1982-01-01

    In the development of the radio-frequency quadrupole (RFQ) linac, the resonator cavity's mechanical design may be a challenge similar in magnitude to that of the development of the accelerator structure itself. Experience with the all-copper 425-MHz RFQ proof-of-principle linac has demonstrated that the resonator cavity must be structurally stiff and easily tunable. This experience has led to development of copper-plated steel structures having vanes that may be moved within a cylinder for tuning. Design of a flexible vane-to-cylinder radio-frequency (rf) joint, the vane, and the cylinder has many constraints dictated by the small-diameter cavities in the 400-MHz-frequency region. Two types of flexible, mechanical vane-to-cylinder rf joints are being developed at Los Alamos: the C-seal and the rf clamp-joint.

  9. Electromagnetic coupling to centimeter-scale mechanical membrane resonators via RF cylindrical cavities

    Science.gov (United States)

    Martinez, Luis A.; Castelli, Alessandro R.; Delmas, William; Sharping, Jay E.; Chiao, Raymond

    2016-11-01

    We present experimental and theoretical results for the excitation of a mechanical oscillator via radiation pressure with a room-temperature system employing a relatively low-(Q) centimeter-size mechanical oscillator coupled to a relatively low-Q standard three-dimensional radio-frequency (RF) cavity resonator. We describe the forces giving rise to optomechanical coupling using the Maxwell stress tensor and show that nanometer-scale displacements are possible and experimentally observable. The experimental system is composed of a 35 mm diameter silicon nitride membrane sputtered with a 300 nm gold conducting film and attached to the end of a RF copper cylindrical cavity. The RF cavity is operated in its {{TE}}011 mode and amplitude modulated on resonance with the fundamental drum modes of the membrane. Membrane motion is monitored using an unbalanced, non-zero optical path difference, optically filtered Michelson interferometer capable of measuring sub-nanometer displacements.

  10. Temporal coupled mode theory of standing wave resonant cavities for infrared photodetection.

    Science.gov (United States)

    Lesmanne, Emeline; De Lamaestre, Roch Espiau; Fowler, David; Boutami, Salim; Badano, Giacomo

    2015-03-23

    Standing wave resonating cavities have been proposed in the past to increase the performance of infrared detectors by minimizing the volume of photogeneration, hence the noise, while maintaining the same quantum efficiency. We present an approach based on the temporal coupled mode theory to explain their behavior and limitations. If the ratio of the imaginary part of the absorber's dielectric function to the index of the incident medium ε″(d)/n₀ is larger than 1.4, then the absorption cross section σ(a) can attain its maximum value, which for an isolated cavity is approximately 2λ/π. Besides, for σ(a) to exceed the cavity width, the incident medium refractive index must be close to unity. Metallic loss is negligible in the infrared, making those resonators suitable for integration in infrared photodetectors.

  11. Realization of cavity linewidth narrowing via interacting dark resonances in a tripod-type electromagnetically induced transparency system

    CERN Document Server

    Ying, Kang; Chen, Dijun; Cai, Haiwen; Qu, Ronghui

    2014-01-01

    Cavity linewidth narrowing via double-dark resonances has been experimentally observed using the 87Rb Zeeman splitting sublevels. With the steep dispersion led by the interacting dark resonances in the tripodtype electromagnetically induced transparency system, we narrow the cavity linewidth to 250 KHz at room temperature. Furthermore, the position of this ultranarrow cavity linewidth could be tuned in a 60 MHz coupling field detuning range.

  12. Entanglement of resonantly coupled field modes in cavities with vibrating boundaries

    CERN Document Server

    Andreata, M A; Dodonov, V V

    2002-01-01

    We study time dependence of various measures of entanglement (covariance entanglement coefficient, purity entanglement coefficient, normalized distance coefficient, entropic coefficients) between resonantly coupled modes of the electromagnetic field in ideal cavities with oscillating boundaries. Two types of cavities are considered: a three-dimensional cavity possessing eigenfrequencies $\\omega_3=3\\omega_1$, whose wall oscillates at the frequency $\\omega_w=2\\omega_1$, and a one-dimensional (Fabry--Perot) cavity with an equidistant spectrum $\\omega_n= n\\omega_1$, when the distance between perfect mirrors oscillates at the frequencies $\\omega_1$ and $2\\omega_1$. The behaviour of entanglement measures in these cases turns out to be completely different, although all three coefficients demonstrate qualitatively similar time dependences in each case (except for some specific situations, where the covariance entanglement coefficient, based on traces of covariance submatrices, seems to be essentially more sensitive ...

  13. A study of resonant-cavity and fiberglass-filled parallel baffles as duct silencers. [for wind tunnels

    Science.gov (United States)

    Soderman, P. T.

    1982-01-01

    Acoustical performance and pressure drop were measured for two types of splitters designed to attenuate sound propagating in ducts - resonant-cavity baffles and fiberglass-filled baffles. Arrays of four baffles were evaluated in the 7- by 10-foot wind tunnel number 1 at Ames Research Center at flow speeds from 0 to 41 m/sec. The baffles were 2.1 m high, 305 to 406 mm thick, and 3.1 to 4.4 m long. Emphasis was on measurements of silencer insertion loss as affected by variations of such parameters as baffle length, baffle thickness, perforated skin geometry, cavity size and shape, cavity damping, wind speed, and acoustic field directivity. An analytical method for predicting silencer performance is described and compared with measurements. With the addition of cavity damping in the form of 25-mm foam linings, the insertion loss above 250 Hz of the resonant-cavity baffles was improved 2 to 7 db compared with the undamped baffles; the loss became equal to or greater than the insertion loss of comparable size fiberglass baffles at frequencies above 250 Hz. Variations of cavity size and shape showed that a series of cavities with triangular cross-sections (i.e., variable depth) were superior to cavities with rectangular cross sections (i.e., constant depth). In wind, the undamped, resonant-cavity baffles generated loud cavity-resonance tones; the tones could be eliminated by cavity damping.

  14. A research on high-temperature permittivity and loss tangent of low-loss dielectric by resonant-cavity technique

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Resonant-cavity technique was introduced to measure the permittivity and loss tangent of low-loss dielectrics. The dielectric properties at 9-10 GHz are measured accurately at the temperature up to 800 ℃by the resonant cavity technique. The only electrical parameters that need to be measured are quality factors (Q) and resonant length (L) of resonant cavity loaded and unloaded with dielectric sample. Moreover, the error caused by thermal expansion effect was resolved by error analysis and experimental calibration.

  15. Simulation of plasma filled hemispherical cavity as dielectric resonator antenna

    Science.gov (United States)

    Trenchev, G.; Kissóvski, Zh

    2016-10-01

    Plasma antennas are becoming an increasingly interesting research topic because of their uncommon characteristics. They are highly configurable, can be turned on and off rapidly, and exhibit lower thermal noise compared to metal antennas. In recent years, research has been conducted on cylindrical plasma columns sustained by DC, RF or microwave field, and their application as leaky wave antennas or as regular monopole antennas. Dielectric resonator antennas (DRA) with high dielectric permittivity are known for their small size and excellent operating characteristics for modern mobile communications (WiMAX, LTE). Hemispherical dielectric resonator antennas are characterized by simple shape, high radiation efficiency and wide bandwidth. Hemispherical DRA with a low density weakly ionized plasma as dielectric material will combine the positive features of plasma and dielectric antennas, and is particularly interesting, as antennas of this type have not been studied yet. The hemispherical plasma antenna is simulated with Ansoft HFSS in the microwave S-band. Obtained radiation pattern and bandwidth show the advantages of hemispherical plasma antennas for future communication technology.

  16. Radiation Characteristics of 3D Resonant Cavity Antenna with Grid-Oscillator Integrated Inside

    Directory of Open Access Journals (Sweden)

    L. A. Haralambiev

    2014-01-01

    Full Text Available A three-dimensional (3D rectangular cavity antenna with an aperture size of 80 mm × 80 mm and a length of 16 mm, integrated with a four-MESFET transistor grid-oscillator, is designed and studied experimentally. It is found that the use of 3D antenna resonant cavity in case of small or medium gain microwave active cavity antenna leads to effective and stable power combining and radiation. The lack of lateral cavity diffraction and radiation helps in producing a directive gain of about 17 dB and radiation aperture efficiency bigger than 75% at a resonance frequency of 8.62 GHz. Good DC to RF oscillator efficiency of 26%, effective isotropic radiated power (EIRP of 5.2 W, and SSB spectral power density of −82 dBc/Hz are found from the measured data. The 3D antenna cavity serves also as a strong metal container for the solid-state oscillator circuitry.

  17. Resonant-Cavity Driven Alfvén Waves in a Helium-Hydrogen Plasma

    Science.gov (United States)

    Clark, Mary; Dorfman, Seth; Vincena, Steve; Zhu, Ziyan; Carter, Troy

    2016-10-01

    Alfvén waves exist in many regimes. In fusion experiments, they can disrupt fusion processes by scattering particles, and in space, they are proposed to heat the solar corona. In these environments, multiple ion species usually occur. It is therefore relevant to study Alfvén waves carried by multiple ion species in a laboratory device. Here a resonant cavity launches them in UCLA's Large Plasma Device (LaPD) in a helium/hydrogen plasma. In a two-ion species plasma, Alfvén waves propagate in two bands: below the heavy ion cyclotron frequency and between a hybrid frequency and the light ion cyclotron frequency. We observe two Alfvén waves at different frequencies (in different bands) emerge when the resonant cavity is excited at one frequency: one at the driving frequency and one at a lower frequency. The two frequencies and wavelengths agree with the dispersion relation. The resonant cavity theory predicts that the wavelengths should be 4 times the cavity's length; only the high frequency lies close to this prediction. This work was funded by UCLA's Norton Rodman Award, and was performed at the Basic Plasma Science Facility, funded by DoE and NSF.

  18. Multiple harmonic frequencies resonant cavity design and half-scale prototype measurements for a fast kicker

    Science.gov (United States)

    Huang, Yulu; Wang, Haipeng; Rimmer, Robert A.; Wang, Shaoheng; Guo, Jiquan

    2016-12-01

    Quarter wavelength resonator (QWR) based deflecting cavities with the capability of supporting multiple odd-harmonic modes have been developed for an ultrafast periodic kicker system in the proposed Jefferson Lab Electron Ion Collider (JLEIC, formerly MEIC). Previous work on the kicking pulse synthesis and the transverse beam dynamics tracking simulations show that a flat-top kicking pulse can be generated with minimal emittance growth during injection and circulation of the cooling electron bunches. This flat-top kicking pulse can be obtained when a DC component and 10 harmonic modes with appropriate amplitude and phase are combined together. To support 10 such harmonic modes, four QWR cavities are used with 5, 3, 1, and 1 modes, respectively. In the multiple-mode cavities, several slightly tapered segments of the inner conductor are introduced to tune the higher order deflecting modes to be harmonic, and stub tuners are used to fine tune each frequency to compensate for potential errors. In this paper, we summarize the electromagnetic design of the five-mode cavity, including the geometry optimization to get high transverse shunt impedance, the frequency tuning and sensitivity analysis, and the single loop coupler design for coupling to all of the harmonic modes. In particular we report on the design and fabrication of a half-scale copper prototype of this proof-of-principle five-odd-mode cavity, as well as the rf bench measurements. Finally, we demonstrate mode superposition in this cavity experimentally, which illustrates the kicking pulse generation concept.

  19. Phase Noise Enhancement of the GaAs High Electron Mobility Transistors Using Micromachined Cavity Resonators at Ka-band

    Science.gov (United States)

    Song, Insang; Kim, Chungwoo; Kwon, Youngwoo; Cheon, Changyul; Song, Cimoo

    1999-06-01

    We introduce a new structure of the micromachined cavity resonator coupled GaAs-based oscillator to enhance the phase noise and the frequency stability. The oscillator and the cavity are designed for Ka-band applications. Compared to the free running oscillator, the cavity resonator coupled oscillator showed the phase noise enhancement of about 20 dB. The phase noises of about -110 and -85 dBc/Hz are obtained at 1 MHz and 100 kHz offset frequency, respectively. The frequency pushing for the gate bias of the cavity coupled oscillator is about two order of magnitude less than that of the free running oscillator.

  20. Generation of GHZ entangled states of photons in multiple cavities via a superconucting qubit or an atom through resonant interaction

    CERN Document Server

    Yang, Chui-Ping

    2012-01-01

    We propose a method to generate a GHZ entangled state of n photons in n microwave cavities (or resonators) via resonant interaction to a single superconducting qubit. By performing local operations on a qubit (e.g., a solid-state qubit, an atom, etc.) placed in each cavity, the created GHZ states of n photons can be transferred to qubits for storage. The proposed scheme greatly reduces effect of decoherence since only resonant qubit-cavity interaction and resonant qubit-pulse interaction are involved, and no measurement is required. In addition, we show that the method can be applied to create a GHZ state of photons in multiple cavities via an atom through resonant interaction with no measurement needed.

  1. Electromagnetic Response of High-Frequency Gravitational Waves by Coupling Open Resonant Cavity

    Institute of Scientific and Technical Information of China (English)

    LI Fang-Yu; CHEN Ying; WANG Ping

    2007-01-01

    We present a new detecting scheme of high-frequency gravitational waves(HFGWs) in the GHz band,the scheme consists of a high-quality-factor open microwave cavity,a static magnetic field passing through the cavity and an electromagnetic (EM)normal mode stored in the cavity.It is found that under the resonant condition firstand second-order perturbation EM effects have almost the same detecting sensitivity to the HFGWs in the GHz band (h~10-26,v~5GHz),but the former contains more information from the HFGWs.We akso provide a very brief review for possible improving way of the sensitivity.This scheme would be Highly complementary to other schemes of detecting the HFGWs.

  2. Electrically detected magnetic resonance in a W-band microwave cavity

    Energy Technology Data Exchange (ETDEWEB)

    Lang, V.; Lo, C. C.; George, R. E.; Lyon, S. A.; Bokor, J.; Schenkel, T.; Ardavan, A.; Morton, J. J. L.

    2011-01-14

    We describe a low-temperature sample probe for the electrical detection of magnetic resonance in a resonant W-band (94 GHz) microwave cavity. The advantages of this approach are demonstrated by experiments on silicon field-effect transistors. A comparison with conventional low-frequency measurements at X-band (9.7 GHz) on the same devices reveals an up to 100-fold enhancement of the signal intensity. In addition, resonance lines that are unresolved at X-band are clearly separated in the W-band measurements. Electrically detected magnetic resonance at high magnetic fields and high microwave frequencies is therefore a very sensitive technique for studying electron spins with an enhanced spectral resolution and sensitivity.

  3. An unobtrusive liquid sensor utilizing a micromilled RF spark gap transmitter and resonant cavity

    Science.gov (United States)

    Berry, H.; Wilson, C.

    2009-09-01

    This paper reports on a new dielectric liquid sensor that utilizes an RF sparkgap transmitter coupled with an aluminum microwave resonant cavity. The transmitter is a micromilled polymer transmitter housing with patterned copper electrodes that generate micro-arcs. This transmitter which operates outside the measured liquid generates a directed ultrawideband signal which is received by the aluminum waveguide. Absorption resonances in the microwave cavity, measured with a spectrum analyzer are a function of the liquids' dielectric constant at lower frequencies, as well as from molecular vibrations/rotations at higher frequencies. In many chemical manufacturing processes, liquids being manufactured are removed, tested in a lab, and then disposed of, or else they will contaminate the full batch. In beer brewing, for instance, samples are removed, density tested for alcohol content, then disposed of. Using this sensor, the chemical process could be continuously monitored by a computerized system without risk of contamination.

  4. Resonant cavity enhanced light harvesting in flexible thin-film organic solar cells.

    Science.gov (United States)

    Sergeant, Nicholas P; Niesen, Bjoern; Liu, Albert S; Boman, Lee; Stoessel, Chris; Heremans, Paul; Peumans, Peter; Rand, Barry P; Fan, Shanhui

    2013-05-01

    Dielectric/metal/dielectric (DMD) electrodes have the potential to significantly increase the absorption efficiency and photocurrent in flexible organic solar cells. We demonstrate that this enhancement is attributed to a broadband cavity resonance. Silver-based semitransparent DMD electrodes with sheet resistances below 10 ohm/sq. are fabricated on flexible polyethylene terephthalate (PET) substrates in a high-throughput roll-to-roll sputtering tool. We carefully study the effect of the semitransparent DMD electrode (here composed of Zn(x)Sn(y)O(z)/Ag/In(x)Sn(y)O(z)) on the optical device performance of a copper phthalocyanine (CuPc)/fullerene (C60) bilayer cell and illustrate that a resonant cavity enhanced light trapping effect dominates the optical behavior of the device.

  5. Resonant cavity enhanced light harvesting in flexible thin-film organic solar cells

    KAUST Repository

    Sergeant, Nicholas P.

    2013-04-24

    Dielectric/metal/dielectric (DMD) electrodes have the potential to significantly increase the absorption efficiency and photocurrent in flexible organic solar cells. We demonstrate that this enhancement is attributed to a broadband cavity resonance. Silver-based semitransparent DMD electrodes with sheet resistances below 10 ohm/sq. are fabricated on flexible polyethylene terephthalate (PET) substrates in a high-throughput roll-to-roll sputtering tool. We carefully study the effect of the semitransparent DMD electrode (here composed of ZnxSnyOz/Ag/InxSn yOz) on the optical device performance of a copper phthalocyanine (CuPc)/fullerene (C60) bilayer cell and illustrate that a resonant cavity enhanced light trapping effect dominates the optical behavior of the device. © 2013 Optical Society of America.

  6. High-performance Refractive Index Sensor Based on Photonic Crystal Single Mode Resonant Micro-cavity

    Institute of Scientific and Technical Information of China (English)

    Shengye Huang; Junfeng Shi; Dongsheng Wang; Wei Li

    2006-01-01

    An effective refractive index sensor built with square lattice photonic crystal is proposed, which can be applicable to photonic integrated circuits. Two photonic crystal waveguides rather than conventional ridge waveguides are used as entrance/exit waveguides to the micro-cavity. Three layers of photonic lattice are set between the photonic crystal waveguides and the micro-cavity to achieve both a high transmission and a high sensitivity. The plane wave method is utilized to calculate the disperse curves and the finite difference time domain scheme is employed to simulate the light propagation. At the resonant wavelength of about 1500 nm, the resonant wavelength shifts up by 0.7 nm for each increment of △n=0.001. A transmission of more than 0.75 is observed. Although the position disorder of the photonic crystal doesn't affect the sensitivity of the sensor,the transmission reduces rapidly as the disorder increases.

  7. High-Precision Resonant Cavity Beam Position, Emittance And Third-Moment Monitors

    Energy Technology Data Exchange (ETDEWEB)

    Barov, N.; Kim, J.S.; Weidemann, A.W.; /FARTECH, San Diego; Miller, R.H.; Nantista, C.D.; /SLAC

    2006-03-14

    Linear colliders and FEL facilities need fast, nondestructive beam position and profile monitors to facilitate machine tune-up, and for use with feedback control. FAR-TECH, Inc., in collaboration with SLAC, is developing a resonant cavity diagnostic to simultaneously measure the dipole, quadrupole and sextupole moments of the beam distribution. Measurements of dipole and quadrupole moments at multiple locations yield information about beam orbit and emittance. The sextupole moment can reveal information about beam asymmetry which is useful in diagnosing beam tail deflections caused by short-range dipole wakefields. In addition to the resonance enhancement of a single-cell cavity, use of a multi-cell standing-wave structure further enhances signal strength and improves the resolution of the device. An estimated resolution is better than 1 {micro}m in rms beam size and better than 1 nm in beam position.

  8. High-efficiency degenerate four wave-mixing in triply resonant nanobeam cavities

    CERN Document Server

    Lin, Zin; Loncar, Marko; Johnson, Steven G; Rodriguez, Alejandro W

    2013-01-01

    We demonstrate high-efficiency, degenerate four-wave mixing in triply resonant Kerr $\\chi^(3)$ photonic crystal (PhC) nanobeam cavities. Using a combination of temporal coupled mode theory and nonlinear finite-difference time-domain (FDTD) simulations, we study the nonlinear dynamics of resonant four-wave mixing processes and demonstrate the possibility of observing high-efficiency limit cycles and steady-state conversion corresponding to $\\approx 100$% depletion of the pump light at low powers, even including effects due to losses, self- and cross-phase modulation, and imperfect frequency matching. Assuming operation in the telecom range, we predict close to perfect quantum efficiencies at reasonably low $\\sim$ 50 mW input powers in silicon micrometer-scale cavities.

  9. Coherent quantum state storage and transfer between two phase qubits via a resonant cavity.

    Science.gov (United States)

    Sillanpää, Mika A; Park, Jae I; Simmonds, Raymond W

    2007-09-27

    As with classical information processing, a quantum information processor requires bits (qubits) that can be independently addressed and read out, long-term memory elements to store arbitrary quantum states, and the ability to transfer quantum information through a coherent communication bus accessible to a large number of qubits. Superconducting qubits made with scalable microfabrication techniques are a promising candidate for the realization of a large-scale quantum information processor. Although these systems have successfully passed tests of coherent coupling for up to four qubits, communication of individual quantum states between superconducting qubits via a quantum bus has not yet been realized. Here, we perform an experiment demonstrating the ability to coherently transfer quantum states between two superconducting Josephson phase qubits through a quantum bus. This quantum bus is a resonant cavity formed by an open-ended superconducting transmission line of length 7 mm. After preparing an initial quantum state with the first qubit, this quantum information is transferred and stored as a nonclassical photon state of the resonant cavity, then retrieved later by the second qubit connected to the opposite end of the cavity. Beyond simple state transfer, these results suggest that a high-quality-factor superconducting cavity could also function as a useful short-term memory element. The basic architecture presented here can be expanded, offering the possibility for the coherent interaction of a large number of superconducting qubits.

  10. Low loss optical waveguide crossing based on octagonal resonant cavity coupling

    Institute of Scientific and Technical Information of China (English)

    Mohd. Zahed M. Khan

    2009-01-01

    A waveguide crossing utilizing a high index contrast material system is presented. The structure is based on coupling with an octagonal resonant cavity inscrted at the waveguide junction. It also employs four identical square metal strips placed at the four comers of the waveguide crossing. The spectral response of the structure calculated using the method of line numerical technique, in general, shows a high power transmission in the forward arm with sufficiently low crosstalk and fraction of radiated power.

  11. Resonance frequency shift in a cavity with a thin conducting film near a conducting wall

    Energy Technology Data Exchange (ETDEWEB)

    Braggio, C. [Dipartimento di Fisica, Universita di Ferrara and INFN, Via del Paradiso 12, 44100 Ferrara (Italy)]. E-mail: caterina.braggio@lnl.infn.it; Bressi, G. [INFN, Sezione di Pavia, Via Bassi 6, 27100 Pavia (Italy); Carugno, G. [INFN, Sezione di Padova, Via F. Marzolo 8, 35131 Padova (Italy); Dodonov, A.V. [Departamento de Fisica, Universidade Federal de Sao Carlos, Via Washington Luiz, Km 235, Sao Carlos 13565-905, SP (Brazil); Dodonov, V.V. [Instituto de Fisica, Universidade de Brasilia, Caixa Postal 04455, 70910-900 Brasilia, DF (Brazil)]. E-mail: vdodonov@fis.unb.br; Galeazzi, G. [INFN, LNL, Viale dell' Universita 2, 35020 Legnaro (Italy); Ruoso, G. [INFN, LNL, Viale dell' Universita 2, 35020 Legnaro (Italy); Zanello, D. [INFN, Sezione di Roma, Piazzale A. Moro 2, 00185 Roma (Italy)

    2007-03-19

    We show that a very thin conducting film (whose thickness can be much smaller than the skin depth), placed nearby a wall of an electromagnetic cavity, can produce the same shift of the resonance frequency as a bulk conducting slab, provided the displacement of the film from the wall is much bigger than the skin depth. We derive a simple analytical formula for the frequency shift and compare it with exact numerical calculations and experimental data.

  12. Pathologies of the uterine endometrial cavity: usual and unusual manifestations and pitfalls on magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Takeuchi, Mayumi; Matsuzaki, Kenji; Yoshida, Shusaku; Nishitani, Hiromu [University of Tokushima, Department of Radiology, Tokushima (Japan); Uehara, Hisanori [University of Tokushima, Department of Molecular and Environmental Pathology, Tokushima (Japan); Shimazu, Hideki [Oe Kyoudo Hospital, Department of Radiology (Japan)

    2005-11-01

    The endometrial cavity may demonstrate various imaging manifestations such as normal, reactive, inflammatory, and benign and malignant neoplasms. We evaluated usual and unusual magnetic resonance imaging (MRI) findings of the uterine endometrial cavity, and described the diagnostic clues to differential diagnoses. Surgically proven pathologies of the uterine endometrial cavity were evaluated retrospectively with pathologic correlation. The pathologies included benign endometrial neoplasms such as endometrial hyperplasia and polyp, malignant endometrial neoplasms such as endometrial carcinoma and carcinosarcoma, endometrial-myometrial neoplasm such as endometrial stromal sarcoma, pregnancy-related lesions in the endometrial cavity such as gestational trophoblastic diseases (hydatidiform mole, invasive mole and choriocarcinoma) and placental polyp, myometrial lesions simulating endometrial lesions such as submucosal leiomyoma and some adenomyosis, endometrial neoplasms simulating myometrial lesions such as adenomyomatous polyp and endometrial lesions arising in the hemicavity of a septate/bicornate uterus, and fluid collections in the uterine cavity (hydro/hemato/pyometra). It is important to recognize various imaging findings in these diseases, in order to make a correct preoperative diagnosis. (orig.)

  13. Optically tunable Fano resonance in a grating-based Fabry-Perot cavity-coupled microring resonator on a silicon chip.

    Science.gov (United States)

    Zhang, Weifeng; Li, Wangzhe; Yao, Jianping

    2016-06-01

    A grating-based Fabry-Perot (FP) cavity-coupled microring resonator on a silicon chip is reported to demonstrate an all-optically tunable Fano resonance. In the device, an add-drop microring resonator (MRR) is employed, and one of the two bus waveguides is replaced by an FP cavity consisting of two sidewall Bragg gratings. By choosing the parameters of the gratings, the resonant mode of the FP cavity is coupled to one of the resonant modes of the MRR. Due to the coupling between the resonant modes, a Fano resonance with an asymmetric line shape resulted. Measurement results show a Fano resonance with an extinction ratio of 22.54 dB, and a slope rate of 250.4 dB/nm is achieved. A further study of the effect of the coupling on the Fano resonance is performed numerically and experimentally. Thanks to the strong light-confinement capacity of the MRR and the FP cavity, a strong two-photon absorption induced nonlinear thermal-optic effect resulted, which is used to tune the Fano resonance optically.

  14. Non-intrusive tunable resonant microwave cavity for optical detected magnetic resonance of NV centres in nanodiamonds

    Science.gov (United States)

    Le Floch, Jean-Michel; Bradac, Carlo; Volz, Thomas; Tobar, Michael E.; Castelletto, Stefania

    2013-12-01

    Optically detected magnetic resonance (ODMR) in nanodiamond nitrogen-vacancy (NV) centres is usually achieved by applying a microwave field delivered by micron-size wires, strips or antennas directly positioned in very close proximity (~ μm) of the nanodiamond crystals. The microwave field couples evanescently with the ground state spin transition of the NV centre (2.87 GHz at zero magnetic field), which results in a reduction of the centre photoluminescence. We propose an alternative approach based on the construction of a dielectric resonator. We show that such a resonator allows for the efficient detection of NV spins in nanodiamonds without the constraints associated to the laborious positioning of the microwave antenna next to the nanodiamonds, providing therefore improved flexibility. The resonator is based on a tunable Transverse Electric Mode in a dielectric-loaded cavity, and we demonstrate that the resonator can detect single NV centre spins in nanodiamonds using less microwave power than alternative techniques in a non-intrusive manner. This method can achieve higher precision measurement of ODMR of paramagnetic defects spin transition in the micro to millimetre-wave frequency domain. Our approach would permit the tracking of NV centres in biological solutions rather than simply on the surface, which is desirable in light of the recently proposed applications of using nanodiamonds containing NV centres for spin labelling in biological systems with single spin and single particle resolution.

  15. Development of automatic impedance matching system for hyperthermia treatment using resonant cavity applicator.

    Science.gov (United States)

    Shindo, Y; Kato, K; Hirashima, T; Yabuhara, T

    2008-01-01

    In this paper, we discuss a new system to make impedance matching automatically for a re-entrant resonant cavity applicator for brain tumor hyperthermia treatment non-invasively. We have already discussed about the effectiveness of the heating method using manual type impedance matching controller, with experiments of heating an agar phantom and computer simulations. However, it becomes difficult to perform an accurate impedance matching as resonant frequency becomes high. Here, in order to make a more accurate impedance matching, we developed the automatic impedance matching system (AIMS). We noticed that the reflected power was generated when the impedance matching was not complete. In this system, therefore, to reduce the reflected power fed back, the stepping motor to turn the dial of variable capacitors is controlled by developed software. To evaluate the developed AIMS, the experiments of heating the agar phantom were performed. From these results, we found that the temperature rise of the agar phantom by using AIMS was about 180% of using manual type controller under the same heating condition. It was found that the proposed system was very effective for hyperthermia treatment using resonant cavity applicator even when the resonant frequency was high.

  16. Local thermal resonance control of GaInP photonic crystal membrane cavities using ambient gas cooling

    CERN Document Server

    Sokolov, Sergei; Yüce, Emre; Combrié, Sylvain; Lehoucq, Gaelle; De Rossi, Alfredo; Mosk, Allard P

    2015-01-01

    We perform a spatially dependent tuning of a GaInP photonic crystal cavity using a continuous wave violet laser. Local tuning is obtained by laser heating of the photonic crystal membrane. The cavity resonance shift is measured for different pump positions and for two ambient gases: helium and nitrogen. The use of high-conducting gas in combination with low-conducting semiconductor leads to a resonance control with a spatial resolution better than 4 microns.

  17. Study of Antenna Superstrates Using Metamaterials for Directivity Enhancement Based on Fabry-Perot Resonant Cavity

    Directory of Open Access Journals (Sweden)

    Haixia Liu

    2013-01-01

    Full Text Available Metamaterial superstrate is a significant method to obtain high directivity of one or a few antennas. In this paper, the characteristics of directivity enhancement using different metamaterial structures as antenna superstrates, such as electromagnetic bandgap (EBG structures, frequency selective surface (FSS, and left-handed material (LHM, are unifiedly studied by applying the theory of Fabry-Perot (F-P resonant cavity. Focusing on the analysis of reflection phase and magnitude of superstrates in presently proposed designs, the essential reason for high-directivity antenna with different superstrates can be revealed in terms of the F-P resonant theory. Furthermore, a new design of the optimum reflection coefficient of superstrates for the maximum antenna directivity is proposed and validated. The optimum location of the LHM superstrate which is based on a refractive lens model can be determined by the F-P resonant distance.

  18. A study of nasal cavity volume in patients with cleft lip and palate by magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, Kenichi [Showa Univ., Tokyo (Japan). School of Medicine

    1996-02-01

    Nasal cavity volume was studied in 11 patients with cleft lip and palate by magnetic resonance imaging. The areas of horizontal sections of the nasal cavity on the cleft and non-cleft sides were measured with the help of a personal computer and image analyzing software. Nasal cavity volume was determined by integrated volume calculation. The volume of each side was measured before and after cleft lip repair. Before cleft lip repair nasal cavity volume on the non-cleft side was larger than on the cleft side. However there was no significant difference in the volume of the cleft and non-cleft sides after cleft lip repair. (author)

  19. Surface-Plasmon-Polariton Laser based on an Open-Cavity Fabry-Perot Resonator

    CERN Document Server

    Zhu, Wenqi; Agrawal, Amit; Lezec, Henri J

    2016-01-01

    Recent years have witnessed growing interest in the development of small-footprint lasers for potential applications in small-volume sensing and on-chip optical communications. Surface-plasmons, electromagnetic modes evanescently confined to metal-dielectric interfaces, offer an effective route to achieving lasing at nanometer-scale dimensions when resonantly amplified in contact with a gain-medium. Here, we achieve visible frequency ultra-narrow linewidth lasing at room-temperature by leveraging surface plasmons propagating in an open Fabry-Perot cavity formed by a flat metal surface coated with a subwavelength-thick layer of optically-pumped gain medium and orthogonally bound by a pair of flat metal sidewalls. Low perturbation transmission-configuration sampling of the lasing plasmon mode is achieved via an evanescently coupled recessed nanoslit, opening the way to high-figure-of-merit refractive-index sensing of analytes interacting with the open cavity.

  20. Plasmonic Metasurfaces Based on Nanopin-Cavity Resonator for Quantitative Colorimetric Ricin Sensing.

    Science.gov (United States)

    Fan, Jiao-Rong; Zhu, Jia; Wu, Wen-Gang; Huang, Yun

    2017-01-01

    In view of the toxic potential of a bioweapon threat, rapid visual recognition and sensing of ricin has been of considerable interest while remaining a challenging task up to date. In this study, a gold nanopin-based colorimetric sensor is developed realizing a multicolor variation for ricin qualitative recognition and analysis. It is revealed that such plasmonic metasurfaces based on nanopin-cavity resonator exhibit reflective color appearance, due to the excitation of standing-wave resonances of narrow bandwidth in visible region. This clear color variation is a consequence of the reflective color mixing defined by different resonant wavelengths. In addition, the colored metasurfaces appear sharp color difference in a narrow refractive index range, which makes them especially well-suited for sensing applications. Therefore, this antibody-functionalized nanopin-cavity biosensor features high sensitivity and fast response, allowing for visual quantitative ricin detection within the range of 10-120 ng mL(-1) (0.15 × 10(-9) -1.8 × 10(-9) m), a limit of detection of 10 ng mL(-1) , and the typical measurement time of less than 10 min. The on-chip integration of such nanopin metasurfaces to portable colorimetric microfluidic device may be envisaged for the quantitative studies of a variety of biochemical molecules.

  1. Investigation of Fano resonances induced by higher order plasmon modes on a circular nano-disk with an elongated cavity

    KAUST Repository

    Amin, Muhammad Ruhul

    2012-08-10

    In this paper, a planar metallic nanostructure design, which supports two distinct Fano resonances in its extinction cross-section spectrum under normally incident and linearly polarized electromagnetic field, is proposed. The proposed design involves a circular disk embedding an elongated cavity; shifting and rotating the cavity break the symmetry of the structure with respect to the incident field and induce higher order plasmon modes. As a result, Fano resonances are generated in the visible spectrum due to the destructive interference between the sub-radiant higher order modes and super-radiant the dipolar mode. The Fano resonances can be tuned by varying the cavity\\'s width and the rotation angle. An RLC circuit, which is mathematically equivalent to a mass-spring oscillator, is proposed to model the optical response of the nanostructure design.

  2. A resonance shift prediction based on the Boltzmann-Ehrenfest principle for cylindrical cavities with a rigid sphere

    DEFF Research Database (Denmark)

    Orozco Santillan, Arturo; Cutanda Henríquez, Vicente

    2008-01-01

    An investigation on the resonance frequency shift for a plane-wave mode in a cylindrical cavity produced by a rigid sphere is reported in this paper. This change of the resonance frequency has been previously considered as a cause of oscillational instabilities in singlemode acoustic levitation...

  3. Device Fabrication of 60 μm Resonant Cavity Light-Emitting Diode

    Directory of Open Access Journals (Sweden)

    J. J. C. Reyes

    2004-12-01

    Full Text Available An array of 60-mm-diameter resonant cavity light-emitting diodes suited for coupling with fiber opticwere fabricated using standard device fabrication technique. I-V characterization was used to determinethe viability of the device fabricating process. Under forward bias, the turn-on voltage of the devices is1.95–2.45 V with a series resistance of 17–14 kW. Under reverse bias, the devices showed a breakdownvoltage of 35 V.

  4. Design of Transparent Anodes for Resonant Cavity Enhanced Light Harvesting in Organic Solar Cells

    KAUST Repository

    Sergeant, Nicholas P.

    2012-01-03

    The use of an ITO-free MoO 3/Ag/MoO 3 anode to control the photon harvesting in PCDTBT:PC 70BM solar cells is proposed. At first sight, the fact that these anodes possess reduced far-field transmission compared to ITO may seem to be a disadvantage. But, despite this, we show that by carefully tuning the resonant optical cavity we can enhance the external quantum efficiency close to the band edge of PCDTBT, resulting in high photocurrent and power conversion efficiency on par with ITO. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. A pulsated weak-resonant-cavity laser diode with transient wavelength scanning and tracking for injection-locked RZ transmission.

    Science.gov (United States)

    Lin, Gong-Ru; Chi, Yu-Chieh; Liao, Yu-Sheng; Kuo, Hao-Chung; Liao, Zhi-Wang; Wang, Hai-Lin; Lin, Gong-Cheng

    2012-06-18

    By spectrally slicing a single longitudinal-mode from a master weak-resonant-cavity Fabry-Perot laser diode with transient wavelength scanning and tracking functions, the broadened self-injection-locking of a slave weak-resonant-cavity Fabry-Perot laser diode is demonstrated to achieve bi-directional transmission in a 200-GHz array-waveguide-grating channelized dense-wavelength-division-multiplexing passive optical network system. Both the down- and up-stream slave weak-resonant-cavity Fabry-Perot laser diodes are non-return-to-zero modulated below threshold and coherently injection-locked to deliver the pulsed carrier for 25-km bi-directional 2.5 Gbits/s return-to-zero transmission. The master weak-resonant-cavity Fabry-Perot laser diode is gain-switched at near threshold condition and delivers an optical coherent pulse-train with its mode linewidth broadened from 0.2 to 0.8 nm by transient wavelength scanning, which facilitates the broadband injection-locking of the slave weak-resonant-cavity Fabry-Perot laser diodes with a threshold current reducing by 10 mA. Such a transient wavelength scanning induced spectral broadening greatly releases the limitation on wavelength injection-locking range required for the slave weak-resonant-cavity Fabry-Perot laser diode. The theoretical modeling and numerical simulation on the wavelength scanning and tracking effects of the master and slave weak-resonant-cavity Fabry-Perot laser diodes are performed. The receiving power sensitivity for back-to-back transmission at bit-error-rate transmission is less than 2 dB for all 16 channels.

  6. Double resonant absorption measurement of acetylene symmetric vibrational states probed with cavity ring down spectroscopy

    CERN Document Server

    Karhu, J; Vainio, M; Metsälä, M; Hoekstra, S; Halonen, L

    2016-01-01

    A novel mid-infrared/near-infrared double resonant absorption setup for studying infrared-inactive vibrational states is presented. A strong vibrational transition in the mid-infrared region is excited using an idler beam from a singly resonant continuous-wave optical parametric oscillator, to populate an intermediate vibrational state. High output power of the optical parametric oscillator and the strength of the mid-infrared transition result in efficient population transfer to the intermediate state, which allows measuring secondary transitions from this state with a high signal-to-noise ratio. A secondary, near-infrared transition from the intermediate state is probed using cavity ring down spectroscopy, which provides high sensitivity in this wavelength region. Due to the narrow linewidths of the excitation sources, the rovibrational lines of the secondary transition are measured with sub-Doppler resolution. The setup is used to access a previously unreported symmetric vibrational state of acetylene, $\

  7. Color-Tunable Resonant Photoluminescence and Cavity-Mediated Multistep Energy Transfer Cascade.

    Science.gov (United States)

    Okada, Daichi; Nakamura, Takashi; Braam, Daniel; Dao, Thang Duy; Ishii, Satoshi; Nagao, Tadaaki; Lorke, Axel; Nabeshima, Tatsuya; Yamamoto, Yohei

    2016-07-26

    Color-tunable resonant photoluminescence (PL) was attained from polystyrene microspheres doped with a single polymorphic fluorescent dye, boron-dipyrrin (BODIPY) 1. The color of the resonant PL depends on the assembling morphology of 1 in the microspheres, which can be selectively controlled from green to red by the initial concentration of 1 in the preparation process of the microspheres. Studies on intersphere PL propagation with multicoupled microspheres, prepared by micromanipulation technique, revealed that multistep photon transfer takes place through the microspheres, accompanying energy transfer cascade with stepwise PL color change. The intersphere energy transfer cascade is direction selective, where energy donor-to-acceptor down conversion direction is only allowed. Such cavity-mediated long-distance and multistep energy transfer will be advantageous for polymer photonics device application.

  8. Sensitivity of surface resistance measurement of HTS thin films by cavity resonator, dielectric resonator and microstrip line resonator

    Indian Academy of Sciences (India)

    N D Kataria; Mukul Misra; R Pinto

    2002-05-01

    Microwave surface resistance s of silver-doped YBa2Cu3O7- (YBCO) thin film, deposited by laser ablation technique on 10 mm × 10 mm LaAlO3 substrate, has been measured by resonant techniques in the frequency range from 5 GHz to 20 GHz. The geometrical factor of the sample and the resonator has been determined theoretically by the knowledge of the electromagnetic field distribution in the resonators. The microwave surface resistance of the superconducting sample is then extracted from the measured value as a function of temperature. The sensitivity of the s measurement, that is, the relative change in the value with the change in the s value is determined for each resonator.

  9. Shielding effectiveness of rectangular cavity made of a new shielding material and resonance suppression

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    New shielding material has become an alternative to traditional metal to shield boxes from electromagnetic interferences. This article introduces the theory of transmission line method to study the shield boxes made of a new sort of material, and then expands the fundamental formulas to deal with the cases of multiple holes and polarization with arbitrary angle. By means of genetic algorithms with the aid of a three dimensional simulation tool, the damping of electromagnetic resonances in enclosures is researched.The computation indicates that under resonant frequency, electromagnetic resonance results in low, even negative shielding coefficient; whereas, for the same areas, shielding effectiveness of a single hole is worse than that of multiple holes. Shielding coefficient varies when polarization angle increases, and the coupled field through the rectangular aperture with the long side parallel to the thin wire is much weaker than that with the long side vertical to the thin wire. By using the metallic-loss dielectric layer of optimized calculation on the internal surface of the cavity, the best result of resonance suppression has been realized with the same thickness of coating. Finally, according to the calculation result, suggestions for shielding are proposed.

  10. Comparison of four computational methods for computing Q factors and resonance wavelengths in photonic crystal membrane cavities

    DEFF Research Database (Denmark)

    de Lasson, Jakob Rosenkrantz; Frandsen, Lars Hagedorn; Burger, Sven

    2016-01-01

    We benchmark four state-of-the-art computational methods by computing quality factors and resonance wavelengths in photonic crystal membrane L5 and L9 line defect cavities.The convergence of the methods with respect to resolution, degrees of freedom and number ofmodes is investigated. Special...... attention is paid to the influence of the size of the computational domain. Convergence is not obtained for some of the methods, indicating that some are moresuitable than others for analyzing line defect cavities....

  11. Doubly-Resonant Fabry-Perot Cavity for Power Enhancement of Burst-Mode Picosecond Ultraviolet Pulses

    Energy Technology Data Exchange (ETDEWEB)

    Abudureyimu, Reheman [ORNL; Huang, Chunning [ORNL; Liu, Yun [ORNL

    2015-01-01

    We report on a first experimental demonstration of locking a doubly-resonant Fabry-Perot cavity to burst-mode picosecond ultraviolet (UV) pulses by using a temperature controlled dispersion compensation method. This technique will eventually enable the intra cavity power enhancement of burst-mode 402.5MHz/50ps UV laser pulses with a MW level peak power required for the laser assisted H- beam stripping experiment at the Spallation Neutron Source.

  12. Influence of left-handed material on the resonant frequency of resonant cavity%左手介质对谐振腔谐振频率的影响∗

    Institute of Scientific and Technical Information of China (English)

    李培; 王辅忠; 张丽珠; 张光璐

    2015-01-01

    The quality factor and the resonant frequency of a resonant cavity are the key factors that need to be considered in the process of resonator design. The wall of cavity is composed of conductor materials which are effective tools to generate high-frequency oscillation. The microwave cavity is widely used. From the perspective of the circuit, it has almost all the properties of LC resonance unit, such as mode selection. Therefore, it is widely used in filters, matching circuits, and antenna design. In industrial applications, the demand for high-frequency resonant cavity is relatively large. A traditional method can increase the resonant frequency of the resonant cavity by reducing the size of the cavity or using the high-order modes. However, as both approaches have their limitations, the design results are not ideal. By combining theoretical calculation and simulation, the factors that affect the resonant frequency of the resonator are analyzed. The results show the relationship between material properties of the filling medium and the resonant frequency of the cavity. Theoretical calculations show that when the left-handed materials are used as filling materials in the cavity, the resonant frequency can be increased without changing the size of the cavity. The results of high frequency structure simulator also prove the above result. Therefore, the resonant frequency of the resonator cannot be limited by the cavity size. It can be seen from the data that compared with reducing the size of the resonator or using high-order modes, filling left-handed materials can improve resonant frequency to a greater extent. The obtained conclusion shows a further progress compared with the traditional theory and provides a theoretical basis for the exploration and design of novel resonators.

  13. Design of a Novel Polarized Beam Splitter Based on a Two-Dimensional Photonic Crystal Resonator Cavity

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xuan; CHEN Shu-Wen; LIAO Qing-Hua; YU Tian-Bao; LIU Nian-Hua; HUANG Yong-Zhen

    2011-01-01

    @@ We propose and analyze a novel ultra-compact polarization beam splitter based on a resonator cavity in a two-dimensional photonic crystal.The two polarizations can be separated efficientlyby the strong coupling between the microcavities and the waveguides occurring around the resonant frequency of the cavities.The transmittance of two polarized light around 1.55 iim can be more than 98.6%, and the size of the device is less than 15 μm x 13μm,so these features will play an important role in future integrated optical circuits.

  14. Modulating resonance modes and Q value of a CdS nanowire cavity by single Ag nanoparticles.

    Science.gov (United States)

    Zhang, Qing; Shan, Xin-Yan; Feng, Xiao; Wang, Chun-Xiao; Wang, Qu-Quan; Jia, Jin-Feng; Xue, Qi-Kun

    2011-10-12

    Semiconductor nanowire (NW) cavities with tailorable optical modes have been used to develop nanoscale oscillators and amplifiers in microlasers, sensors, and single photon emitters. The resonance modes of NW could be tuned by different boundary conditions. However, continuously and reversibly adjusting resonance modes and improving Q-factor of the cavity remain a great challenge. We report a method to modulate resonance modes continuously and reversibly and improve Q-factor based on surface plasmon-exciton interaction. By placing single Ag nanoparticle (NP) nearby a CdS NW, we show that the wavelength and relative intensity of the resonance modes in the NW cavity can systematically be tuned by adjusting the relative position of the Ag NP. We further demonstrate that a 56% enhancement of Q-factor and an equivalent π-phase shift of the resonance modes can be achieved when the Ag NP is located near the NW end. This hybrid cavity has potential applications in active plasmonic and photonic nanodevices.

  15. Cavity ring-up spectroscopy for dissipative and dispersive sensing in a whispering gallery mode resonator

    CERN Document Server

    Yang, Yong; Kasumie, Sho; Ward, Jonathan M; Chormaic, Síle Nic

    2016-01-01

    In whispering gallery mode resonator sensing applications, the conventional way to detect a change in the parameter to be measured is by observing the steady state transmission spectrum through the coupling waveguide. Alternatively, cavity ring-up spectroscopy (CRUS) sensing can be achieved transiently. In this work, we investigate CRUS using coupled mode equations and find analytical solutions with a large spectral broadening approximation of the input pulse. The relationships between the frequency detuning, coupling gap and ring-up peak height are determined and experimentally verified using an ultrahigh \\textit{Q}-factor silica microsphere. This work shows that distinctive dispersive and dissipative transient sensing can be realised by simply measuring the peak height of the CRUS signal, which might improve the data collection rate.

  16. Label-Free, Single Molecule Resonant Cavity Detection: A Double-Blind Experimental Study

    Directory of Open Access Journals (Sweden)

    Maria V. Chistiakova

    2015-03-01

    Full Text Available Optical resonant cavity sensors are gaining increasing interest as a potential diagnostic method for a range of applications, including medical prognostics and environmental monitoring. However, the majority of detection demonstrations to date have involved identifying a “known” analyte, and the more rigorous double-blind experiment, in which the experimenter must identify unknown solutions, has yet to be performed. This scenario is more representative of a real-world situation. Therefore, before these devices can truly transition, it is necessary to demonstrate this level of robustness. By combining a recently developed surface chemistry with integrated silica optical sensors, we have performed a double-blind experiment to identify four unknown solutions. The four unknown solutions represented a subset or complete set of four known solutions; as such, there were 256 possible combinations. Based on the single molecule detection signal, we correctly identified all solutions. In addition, as part of this work, we developed noise reduction algorithms.

  17. Cavity-aided magnetic-resonance microscopy of atoms in optical lattices

    CERN Document Server

    Purdy, Tom P; Brooks, Daniel W C; Botter, Thierry; Stamper-Kurn, Dan M

    2010-01-01

    Magnetic resonance imaging (MRI) is a powerful technique for investigating the microscopic properties and dynamics of physical systems. In this work we demonstrate state-sensitive MRI of ultracold atoms in an optical lattice. Single-shot spatial resolution is 120 nm, well below the lattice spacing, and number sensitivity is +/-2.4 for 150 atoms on a single site, well below Poissonian atom-number fluctuations. We achieve this by combining high-spatial-resolution control over the atomic spin using an atom chip, together with nearly quantum-limited spin measurement, obtained by dispersively coupling the atoms to light in a high-finesse optical cavity. The MRI is minimally disruptive of the atoms' internal state, preserving the magnetisation of the gas for subsequent experiments. Using this technique, we observe the nonequilibrium transport dynamics of the atoms among individual lattice sites. We see the atom cloud initially expand ballistically, followed by the onset of interaction-inhibited transport.

  18. Quantification of total pigments in citrus essential oils by thermal wave resonant cavity photopyroelectric spectroscopy.

    Science.gov (United States)

    López-Muñoz, Gerardo A; Antonio-Pérez, Aurora; Díaz-Reyes, J

    2015-05-01

    A general theory of thermal wave resonant cavity photopyroelectric spectroscopy (TWRC-PPE) was recently proposed by Balderas-López (2012) for the thermo-optical characterisation of substances in a condensed phase. This theory is used to quantify the total carotenoids and chlorophylls in several folded and un-folded citrus essential oils to demonstrate the viability of using this technique as an alternative analytical method for the quantification of total pigments in citrus oils. An analysis of variance (ANOVA) reveals significant differences (p spectroscopy can be used to quantify concentrations up to five times higher of total carotenoids and chlorophylls in citrus oils than UV-Vis spectroscopy without sample preparation or dilution. The optical limits of this technique and possible interference are also described.

  19. High-quality distributed Bragg reflectors for resonant-cavity light-emitting diode applications

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, S.; Naranjo, F.B.; Calle, F.; Sanchez-Garcia, M.A.; Calleja, E. [ISOM, ETSI Telecomunicacion, Universidad Politecnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid (Spain); Departamento de Ingenieria Electronica, ETSI Telecomunicacion, Universidad Politecnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid (Spain); Vennegues, P. [CHREA-CNRS, Rue Bernard Gregory, Sophia Antipolis, 06560 Valbonne (France)

    2002-08-16

    Efficient distributed Bragg reflectors based on Al{sub x}Ga{sub 1} {sub -} {sub x}N/GaN multilayer stacks have been grown by plasma-assisted molecular-beam epitaxy on GaN/Al{sub 2}O{sub 3} templates. The final goal is to incorporate these reflectors as bottom mirrors in a backside (sapphire) resonant-cavity light-emitting diode at 510 nm. The reflectors have been characterised by atomic force microscopy, high-resolution X-ray diffraction and high-resolution transmission electron microscopy. Reflectivity measurements have also been performed, obtaining values between 30% and 50%, depending on the Al content used. The incorporation of the Al{sub x}Ga{sub 1} {sub -} {sub x}N/GaN Bragg reflector as bottom mirror in a RCLED structure improves the output power by a factor of 12 compared with conventional light-emitting diodes. (Abstract Copyright[2002], Wiley Periodicals, Inc.)

  20. Microcontroller based resonance tracking unit for time resolved continuous wave cavity-ringdown spectroscopy measurements.

    Science.gov (United States)

    Votava, Ondrej; Mašát, Milan; Parker, Alexander E; Jain, Chaithania; Fittschen, Christa

    2012-04-01

    We present in this work a new tracking servoloop electronics for continuous wave cavity-ringdown absorption spectroscopy (cw-CRDS) and its application to time resolved cw-CRDS measurements by coupling the system with a pulsed laser photolysis set-up. The tracking unit significantly increases the repetition rate of the CRDS events and thus improves effective time resolution (and/or the signal-to-noise ratio) in kinetics studies with cw-CRDS in given data acquisition time. The tracking servoloop uses novel strategy to track the cavity resonances that result in a fast relocking (few ms) after the loss of tracking due to an external disturbance. The microcontroller based design is highly flexible and thus advanced tracking strategies are easy to implement by the firmware modification without the need to modify the hardware. We believe that the performance of many existing cw-CRDS experiments, not only time-resolved, can be improved with such tracking unit without any additional modification to the experiment.

  1. A numerically efficient damping model for acoustic resonances in microfluidic cavities

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, P., E-mail: hahnp@ethz.ch; Dual, J. [Institute of Mechanical Systems (IMES), Department of Mechanical and Process Engineering, ETH Zurich, Tannenstrasse 3, CH-8092 Zurich (Switzerland)

    2015-06-15

    Bulk acoustic wave devices are typically operated in a resonant state to achieve enhanced acoustic amplitudes and high acoustofluidic forces for the manipulation of microparticles. Among other loss mechanisms related to the structural parts of acoustofluidic devices, damping in the fluidic cavity is a crucial factor that limits the attainable acoustic amplitudes. In the analytical part of this study, we quantify all relevant loss mechanisms related to the fluid inside acoustofluidic micro-devices. Subsequently, a numerical analysis of the time-harmonic visco-acoustic and thermo-visco-acoustic equations is carried out to verify the analytical results for 2D and 3D examples. The damping results are fitted into the framework of classical linear acoustics to set up a numerically efficient device model. For this purpose, all damping effects are combined into an acoustofluidic loss factor. Since some components of the acoustofluidic loss factor depend on the acoustic mode shape in the fluid cavity, we propose a two-step simulation procedure. In the first step, the loss factors are deduced from the simulated mode shape. Subsequently, a second simulation is invoked, taking all losses into account. Owing to its computational efficiency, the presented numerical device model is of great relevance for the simulation of acoustofluidic particle manipulation by means of acoustic radiation forces or acoustic streaming. For the first time, accurate 3D simulations of realistic micro-devices for the quantitative prediction of pressure amplitudes and the related acoustofluidic forces become feasible.

  2. Magnetometry with nitrogen-vacancy ensembles in diamond based on infrared absorption in a doubly resonant optical cavity

    CERN Document Server

    Dumeige, Yannick; Jacques, Vincent; Treussart, François; Roch, Jean-François; Debuisschert, Thierry; Acosta, Victor; Jarmola, Andrey; Jensen, Kasper; Kehayias, Pauli; Budker, Dmitry

    2013-01-01

    We propose to use an optical cavity to enhance the sensitivity of magnetometers relying on the detection of the spin state of high-density nitrogen-vacancy ensembles in diamond using infrared optical absorption. The role of the cavity is to obtain a contrast in the absorption-detected magnetic resonance approaching unity at room temperature. We project an increase in the photon shot-noise limited sensitivity of two orders of magnitude in comparison with a single-pass approach. Optical losses can limit the enhancement to one order of magnitude which could still enable room temperature operation. Finally, the optical cavity also allows to use smaller pumping power when it is designed to be resonant at both the pump and the signal wavelength.

  3. Nanoscale resonant-cavity-enhanced germanium photodetectors with lithographically defined spectral response for improved performance at telecommunications wavelengths.

    Science.gov (United States)

    Balram, Krishna C; Audet, Ross M; Miller, David A B

    2013-04-22

    We demonstrate the use of a subwavelength planar metal-dielectric resonant cavity to enhance the absorption of germanium photodetectors at wavelengths beyond the material's direct absorption edge, enabling high responsivity across the entire telecommunications C and L bands. The resonant wavelength of the detectors can be tuned linearly by varying the width of the Ge fin, allowing multiple detectors, each resonant at a different wavelength, to be fabricated in a single-step process. This approach is promising for the development of CMOS-compatible devices suitable for integrated, high-speed, and energy-efficient photodetection at telecommunications wavelengths.

  4. Scheme for on-resonance generation of entanglement in time-dependent asymmetric two-qubit-cavity systems

    Science.gov (United States)

    Olaya-Castro, Alexandra; Johnson, Neil F.; Quiroga, Luis

    2004-08-01

    We present an efficient scheme for the controlled generation of pure two-qubit states possessing any desired degree of entanglement and a prescribed symmetry. This is achieved in two-qubit-cavity QED systems (e.g., cold-trapped ions and flying atoms) via on-resonance ion- or atom-cavity couplings, which are time dependent and asymmetric, yielding a trapping vacuum state condition which does not arise for identical couplings. A duality in the role of the coupling ratio yields states with a given concurrence but opposing symmetries. Both the trapping state condition and the resulting entanglement power are robust against decoherence channels.

  5. Local thermal resonance control of GaInP photonic crystal membrane cavities using ambient gas cooling

    Energy Technology Data Exchange (ETDEWEB)

    Sokolov, Sergei, E-mail: s.sokolov@utwente.nl; Lian, Jin; Yüce, Emre; Mosk, Allard P. [Complex Photonic Systems (COPS), MESA+ Institute for Nanotechnology, University of Twente, 7500 AE Enschede (Netherlands); Combrié, Sylvain; Lehoucq, Gaelle; De Rossi, Alfredo [Thales Research and Technology, Route Départementale 128, 91767 Palaiseau (France)

    2015-04-27

    We perform spatially dependent tuning of a GaInP photonic crystal cavity using a continuous wave violet laser. Local tuning is obtained by laser heating of the photonic crystal membrane. The cavity resonance shift is measured for different pump positions and for two ambient gases: He and N{sub 2}. We find that the width of the temperature profile induced in the membrane depends strongly on the thermal conductivity of the ambient gas. For He gas, a narrow spatial width of the temperature profile of 2.8 μm is predicted and verified in experiment.

  6. A qubit strongly coupled to a resonant cavity: asymmetry of the spontaneous emission spectrum beyond the rotating wave approximation

    Energy Technology Data Exchange (ETDEWEB)

    Cao, X [Department of Physics and Institute of Theoretical Physics and Astrophysics, Xiamen University, Xiamen, 361005 (China); You, J Q; Nori, F [Advanced Science Institute, RIKEN, Wako-shi 351-0198 (Japan); Zheng, H, E-mail: xfcao@xmu.edu.cn [Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2011-07-15

    We investigate the spontaneous emission (SE) spectrum of a qubit in a lossy resonant cavity. We use neither the rotating-wave approximation nor the Markov approximation. For the weak-coupling case, the SE spectrum of the qubit is a single peak, with its location depending on the spectral density of the qubit environment. Then, the asymmetry (of the location and heights of the two peaks) of the two SE peaks (which are related to the vacuum Rabi splitting) changes as the qubit-cavity coupling increases. Explicitly, for a qubit in a low-frequency intrinsic bath, the height asymmetry of the splitting peaks is enhanced as the qubit-cavity coupling strength increases. However, for a qubit in an Ohmic bath, the height asymmetry of the spectral peaks is inverted compared to the low-frequency bath case. With further increasing the qubit-cavity coupling to the ultra-strong regime, the height asymmetry of the left and right peaks is slightly inverted, which is consistent with the corresponding case of a low-frequency bath. This inversion of the asymmetry arises from the competition between the Ohmic bath and the cavity bath. Therefore, after considering the anti-rotating terms, our results explicitly show how the height asymmetry in the SE spectrum peaks depends on the qubit-cavity coupling and the type of intrinsic noise experienced by the qubit.

  7. Double resonant absorption measurement of acetylene symmetric vibrational states probed with cavity ring down spectroscopy

    Science.gov (United States)

    Karhu, J.; Nauta, J.; Vainio, M.; Metsälä, M.; Hoekstra, S.; Halonen, L.

    2016-06-01

    A novel mid-infrared/near-infrared double resonant absorption setup for studying infrared-inactive vibrational states is presented. A strong vibrational transition in the mid-infrared region is excited using an idler beam from a singly resonant continuous-wave optical parametric oscillator, to populate an intermediate vibrational state. High output power of the optical parametric oscillator and the strength of the mid-infrared transition result in efficient population transfer to the intermediate state, which allows measuring secondary transitions from this state with a high signal-to-noise ratio. A secondary, near-infrared transition from the intermediate state is probed using cavity ring-down spectroscopy, which provides high sensitivity in this wavelength region. Due to the narrow linewidths of the excitation sources, the rovibrational lines of the secondary transition are measured with sub-Doppler resolution. The setup is used to access a previously unreported symmetric vibrational state of acetylene, ν 1 + ν 2 + ν 3 + ν4 1 + ν5 - 1 in the normal mode notation. Single-photon transitions to this state from the vibrational ground state are forbidden. Ten lines of the newly measured state are observed and fitted with the linear least-squares method to extract the band parameters. The vibrational term value was measured to be at 9775.0018(45) cm-1, the rotational parameter B was 1.162 222(37) cm-1, and the quartic centrifugal distortion parameter D was 3.998(62) × 10-6 cm-1, where the numbers in the parenthesis are one-standard errors in the least significant digits.

  8. Optimal dielectric and cavity configurations for improving the efficiency of electron paramagnetic resonance probes.

    Science.gov (United States)

    Elnaggar, Sameh Y; Tervo, Richard; Mattar, Saba M

    2014-08-01

    An electron paramagnetic resonance (EPR) spectrometer's lambda efficiency parameter (Λ) is one of the most important parameters that govern its sensitivity. It is studied for an EPR probe consisting of a dielectric resonator (DR) in a cavity (CV). Expressions for Λ are derived in terms of the probe's individual DR and CV components, Λ1 and Λ2 respectively. Two important cases are considered. In the first, a probe consisting of a CV is improved by incorporating a DR. The sensitivity enhancement depends on the relative rather than the absolute values of the individual components. This renders the analysis general. The optimal configuration occurs when the CV and DR modes are nearly degenerate. This configuration guarantees that the probe can be easily coupled to the microwave bridge while maintaining a large Λ. It is shown that for a lossy CV with a small quality factor Q2, one chooses a DR that has the highest filling factor, η1, regardless of its Λ1 and Q1. On the other hand, if the CV has a large Q2, the optimum DR is the one which has the highest Λ1. This is regardless of its η1 and relative dielectric constant, ɛr. When the quality factors of both the CV and DR are comparable, the lambda efficiency is reduced by a factor of 2. Thus the signal intensity for an unsaturated sample is cut in half. The second case is the design of an optimum shield to house a DR. Besides preventing radiation leakage, it is shown that for a high loss DR, the shield can actually boost Λ above the DR value. This can also be very helpful for relatively low efficiency dielectrics as well as lossy samples, such as polar liquids.

  9. Modeling and Simulation of a Resonant-Cavity-Enhanced InGaAs/GaAs Quantum Dot Photodetector

    Directory of Open Access Journals (Sweden)

    W. W. Wang

    2015-01-01

    Full Text Available We simulated and analyzed a resonant-cavity-enhancedd InGaAs/GaAs quantum dot n-i-n photodiode using Crosslight Apsys package. The resonant cavity has a distributed Bragg reflector (DBR at one side. Comparing with the conventional photodetectors, the resonant-cavity-enhanced photodiode (RCE-PD showed higher detection efficiency, faster response speed, and better wavelength selectivity and spatial orientation selectivity. Our simulation results also showed that when an AlAs layer is inserted into the device structure as a blocking layer, ultralow dark current can be achieved, with dark current densities 0.0034 A/cm at 0 V and 0.026 A/cm at a reverse bias of 2 V. We discussed the mechanism producing the photocurrent at various reverse bias. A high quantum efficiency of 87.9% was achieved at resonant wavelength of 1030 nm with a FWHM of about 3 nm. We also simulated InAs QD RCE-PD to compare with InGaAs QD. At last, the photocapacitance characteristic of the model has been discussed under different frequencies.

  10. AZO/Ag/AZO anode for resonant cavity red, blue, and yellow organic light emitting diodes

    Science.gov (United States)

    Gentle, A. R.; Yambem, S. D.; Burn, P. L.; Meredith, P.; Smith, G. B.

    2016-06-01

    Indium tin oxide (ITO) is the transparent electrode of choice for organic light-emitting diodes (OLEDs). Replacing ITO for cost and performance reasons is a major drive across optoelectronics. In this work, we show that changing the transparent electrode on red, blue, and yellow OLEDs from ITO to a multilayer buffered aluminium zinc oxide/silver/aluminium zinc oxide (AZO/Ag/AZO) substantially enhances total output intensity, with better control of colour, its constancy, and intensity over the full exit hemisphere. The thin Ag containing layer induces a resonant cavity optical response of the complete device. This is tuned to the emission spectra of the emissive material while minimizing internally trapped light. A complete set of spectral intensity data is presented across the full exit hemisphere for each electrode type and each OLED colour. Emission zone modelling of output spectra at a wide range of exit angles to the normal was in excellent agreement with the experimental data and hence could, in principle, be used to check and adjust production settings. These multilayer transparent electrodes show significant potential for both eliminating indium from OLEDs and spectrally shaping the emission.

  11. Fano-resonance induced strong-coupling of a hyperbolic cavity to a quantum emitter

    CERN Document Server

    Hasan, Mehedi; Belov, Pavel

    2015-01-01

    Light-matter interaction is studied for an open quantum system in the strong-coupling regime. A quantum dot and a hyperbolic cavity of spherical geometry is shown to couple light with large Rabi frequency and the role of Fano resonance is shown in the coupling mechanism. High Purcell factor and large Lamb shift are outlined. In the near-field spectrum, two distinct anti-crossings are evident, namely -- the one near the epsilon near zero (ENZ) frequency (from the effective medium description) which is detectable in the far-field, and the second anti-crossing is a pseudomode that does not appear in the far-field spectrum. This delineates the phenomenon `farfield propagating large Purcell factor'. Finally, we remark the fidelity of the strong-coupling, i.e. how prone the strong-coupling with respect to the loss mechanisms. This study on strong-coupling will have applications for spectroscopy, control over chemical reaction rate, microcavity, and in quantum information technology.

  12. Fano Resonance Based on Metal-Insulator-Metal Waveguide-Coupled Double Rectangular Cavities for Plasmonic Nanosensors

    Directory of Open Access Journals (Sweden)

    Zhidong Zhang

    2016-05-01

    Full Text Available A refractive index sensor based on metal-insulator-metal (MIM waveguides coupled double rectangular cavities is proposed and investigated numerically using the finite element method (FEM. The transmission properties and refractive index sensitivity of various configurations of the sensor are systematically investigated. An asymmetric Fano resonance lineshape is observed in the transmission spectra of the sensor, which is induced by the interference between a broad resonance mode in one rectangular and a narrow one in the other. The effect of various structural parameters on the Fano resonance and the refractive index sensitivity of the system based on Fano resonance is investigated. The proposed plasmonic refractive index sensor shows a maximum sensitivity of 596 nm/RIU.

  13. Controllable optical response by modifying the gain and loss of a mechanical resonator and cavity mode in an optomechanical system

    CERN Document Server

    Liu, Yu-Long; Zhang, Jing; Özdemir, Şahin Kaya; Yang, Lan; Nori, Franco; Liu, Yu-xi

    2016-01-01

    We theoretically study a strongly-driven optomechanical system which consists of a passive optical cavity and an active mechanical resonator. When the optomechanical coupling strength is varied, phase transitions, which are similar those observed in $\\mathcal{PT}$-symmetric systems, are observed. We show that the optical transmission can be controlled by changing the gain of the mechanical resonator and loss of the optical cavity mode. Especially, we find that: (i) for balanced gain and loss, optical amplification and absorption can be tuned by changing the optomechanical coupling strength through a control field; (ii) for unbalanced gain and loss, even with a tiny mechanical gain, both optomechanically-induced transparency and anomalous dispersion can be observed around a critical point, which exhibits an ultra-long group delay. The time delay $\\tau$ can be optimized by regulating the optomechanical coupling strength through the control field and improved up to several orders of magnitude ($\\tau\\sim2$ $\\math...

  14. A Photonic Crystal Magnetic Field Sensor Using a Shoulder-Coupled Resonant Cavity Infiltrated with Magnetic Fluid.

    Science.gov (United States)

    Su, Delong; Pu, Shengli; Mao, Lianmin; Wang, Zhaofang; Qian, Kai

    2016-12-16

    A kind of photonic crystal magnetic field sensor is proposed and investigated numerically. The shoulder-coupled resonant cavity is introduced in the photonic crystal, which is infiltrated with magnetic fluid. Through monitoring the shift of resonant wavelength, the magnetic field sensing is realized. According to the designed infiltration schemes, both the magnetic field sensitivity and full width at half maximum increase with the number of infiltrated air holes. The figure of merit of the structure is defined to evaluate the sensing performance comprehensively. The best structure corresponding to the optimal infiltration scheme with eight air holes infiltrated with magnetic fluid is obtained.

  15. Noninvasive Vibrational Mode Spectroscopy of Ion Coulomb Crystals through Resonant Collective Coupling to an Optical Cavity Field

    DEFF Research Database (Denmark)

    Dantan, Aurélien; Marler, Joan; Albert, Magnus

    2010-01-01

    We report on a novel noninvasive method to determine the normal mode frequencies of ion Coulomb crystals in traps based on the resonance enhanced collective coupling between the electronic states of the ions and an optical cavity field at the single photon level. Excitations of the normal modes...... are observed through a Doppler broadening of the resonance. An excellent agreement with the predictions of a zero-temperature uniformly charged liquid plasma model is found. The technique opens up for investigations of the heating and damping of cold plasma modes, as well as the coupling between them....

  16. High-Speed Widely-Tunable 90% Quantum-Efficiency Resonant Cavity Enhanced p-i-n Photodiodes

    Science.gov (United States)

    1998-12-01

    REPORT unclassified b . ABSTRACT unclassified c. THIS PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 8:45am - 9...00am WB2 High-Speed Widely-Tunable >90% Quantum-Efficiency Resonant Cavity Enhanced p-i-n Photodiodes Necmi Biyiklia. Ibrahim Kimukinb. Orhan ...Bilkent, Ankara 06533, Turkey. b Department of Physics, Bilkent University, Bilkent, Ankara 06533, Turkey. c Department of Electrical and Computer

  17. Simulation of a birdcage and a ceramic cavity HF-resonator for high magnetic fields in magnetic resonance imaging.

    Science.gov (United States)

    Eriksen, E; Golombeck, M A; Junge, S; Dössel, O

    2002-01-01

    The aim of this work was the 3D-simulation of a dielectric resonator for high-field-MRI. A 12-rod-bird-cage-resonator was simulated in a first step, in order to verify the capability of the commercial simulation software MAFIA to simulate homogeneous, transversal B-fields in resonators. The second step was the simulation of frequency-independent dielectric ceramic resonators for static magnetic field strengths of 7 T and 12 T (294 MHz and 504 MHz respectively). The results were compared to the measured results of a manufactured TiO2- and a Al2O3-resonator. Only minor deviations showed up. These results led to the conclusion that dielectric resonators for high field MRI can be optimised using numerical field calculation software.

  18. Linear and nonlinear resonance features of an erbium-doped fibre ring laser under cavity-loss modulation

    Indian Academy of Sciences (India)

    Aditi Ghosh; R Vijaya

    2014-07-01

    The continuous-wave output of a single-mode erbium-doped fibre ring laser when subjected to cavity-loss modulation is found to exhibit linear as well as nonlinear resonances. At sufficiently low driving amplitude, the system resembles a linear damped oscillator. At higher amplitudes, the dynamical study of these resonances shows that the behaviour of the system exhibits features of a nonlinear damped oscillator under harmonic modulation. These nonlinear dynamical features, including harmonic and subharmonic resonances, have been studied experimentally and analysed with the help of a simple time-domain and frequency-domain information obtained from the output of the laser. All the studies are restricted to the modulation frequency lying in a regime near the relaxation oscillation frequency.

  19. Axially uniform magnetic field-modulation excitation for electron paramagnetic resonance in rectangular and cylindrical cavities by slot cutting

    Science.gov (United States)

    Sidabras, Jason W.; Richie, James E.; Hyde, James S.

    2017-01-01

    In continuous-wave (CW) Electron Paramagnetic Resonance (EPR) a low-frequency time-harmonic magnetic field, called field modulation, is applied parallel to the static magnetic field and incident on the sample. Varying amplitude of the field modulation incident on the sample has consequences on spectral line-shape and line-height over the axis of the sample. Here we present a method of coupling magnetic field into the cavity using slots perpendicular to the sample axis where the slot depths are designed in such a way to produce an axially uniform magnetic field along the sample. Previous literature typically assumes a uniform cross-section and axial excitation due to the wavelength of the field modulation being much larger than the cavity. Through numerical analysis and insights obtained from the eigenfunction expansion of dyadic Green's functions, it is shown that evanescent standing-wave modes with complex cross-sections are formed within the cavity. From this analysis, a W-band (94 GHz) cylindrical cavity is designed where modulation slots are optimized to present a uniform 100 kHz field modulation over the length of the sample.

  20. Compact photonic crystal circulator with flat-top transmission band created by cascading magneto-optical resonance cavities.

    Science.gov (United States)

    Wang, Qiong; Ouyang, Zhengbiao; Lin, Mi; Liu, Qiang

    2015-11-20

    A new type of compact three-port circulator with flat-top transmission band (FTTB) in a two-dimensional photonic crystal has been proposed, through coupling the cascaded magneto-optical resonance cavities to waveguides. The coupled-mode theory is applied to investigate the coupled structure and analyze the condition to achieve FTTB. According to the theoretical analysis, the structure is further optimized to ensure that the condition for achieving FTTB can be satisfied for both cavity-cavity coupling and cavity-waveguide coupling. Through the finite-element method, it is demonstrated that the design can realize a high quality, nonreciprocal circulating propagation of waves with an insertion loss of 0.023 dB and an isolation of 23.3 dB, covering a wide range of operation frequency. Such a wideband circulator has potential applications in large-scale integrated photonic circuits for guiding or isolating harmful optical reflections from load elements.

  1. Efficient second harmonic generation of a diode-laser-pumped CW Nd:YAG laser using monolithic MgO:LiNbO3 external resonant cavities

    Science.gov (United States)

    Kozlovsky, William J.; Nabors, C. D.; Byer, Robert L.

    1988-01-01

    56-percent efficient external-cavity-resonant second-harmonic generation of a diode-laser pumped, CW single-axial-mode Nd:YAG laser is reported. A theory of external doubling with a resonant fundamental is presented and compared to experimental results for three monolithic cavities of nonlinear MgO:LiNbO3. The best conversion efficiency was obtained with a 12.5-mm-long monolithic ring cavity doubler, which produced 29.7 mW of CW, single-axial model 532-nm radiation from an input of 52.5 mW.

  2. Spinal cord cavities; Differential-diagnostic criteria in magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Schubeus, P.; Schoerner, W.; Hosten, N.; Felix, R. (Free University of Berlin, University Clinic Rudolf Virchow, Charlottenburg (Germany). Department of Radiology)

    MRI examinations of 30 patients with idiopathic syringomyelia and 10 patients with cavities associated with an intramedullary neoplasm were evaluated with respect to typical MRI features in both groups. Al tumor-associated cases resembled the idiopathic syringomyelias in some portions of the cavity. At the tumor site, however, tumor-associated cases demonstrated typical findings; the cavities showed abrupt changes of diameter (10/10) and position (8/10) and the surrounding spinal cord demonstrated an uneven thickness (10/10), an increased signal intensity on T2-weighted images (10/10) and pathological contrast enhancement (7/7). Displacement of cerebellar tonsils below the level of the foramen magnum (921/30) and enlargement of the spinal canal (97/29) were characteristic features of idiopathic cases. In conclusion, MRI provides valuable criteria to differentiate between idiopathic and tumor-associated cavities. (author). 19 refs.; 4 figs.; 1 tab.

  3. Determination of the quasi-TE mode (in-plane) graphene linear absorption coefficient via integration with silicon-on-insulator racetrack cavity resonators.

    Science.gov (United States)

    Crowe, Iain F; Clark, Nicholas; Hussein, Siham; Towlson, Brian; Whittaker, Eric; Milosevic, Milan M; Gardes, Frederic Y; Mashanovich, Goran Z; Halsall, Matthew P; Vijayaraghaven, Aravind

    2014-07-28

    We examine the near-IR light-matter interaction for graphene integrated cavity ring resonators based on silicon-on-insulator (SOI) race-track waveguides. Fitting of the cavity resonances from quasi-TE mode transmission spectra reveal the real part of the effective refractive index for graphene, n(eff) = 2.23 ± 0.02 and linear absorption coefficient, α(gTE) = 0.11 ± 0.01dBμm(-1). The evanescent nature of the guided mode coupling to graphene at resonance depends strongly on the height of the graphene above the cavity, which places limits on the cavity length for optical sensing applications.

  4. Coherent coupling of molecular resonators with a micro-cavity mode

    CERN Document Server

    Shalabney, Atef; Hutchison, James A; Pupillo, Guido; Genet, Cyriaque; Ebbesen, Thomas W

    2014-01-01

    Strong coupling is at the heart of optomechanics where it enables coherent quantum state transfer between light and micromechanical oscillators. Strongly coupled molecule-cavity systems have also revealed unique properties enabling even the control of chemical rates through the optical hybridization of the electronic states. Here we combine these notions to show that molecular vibrational modes of the electronic ground state can be coherently coupled with a micro-cavity mode at room temperature, given the low vibrational thermal occupation factors n_{\

  5. Triple-resonant Brillouin light scattering in magneto-optical cavities

    CERN Document Server

    Haigh, J A; Ramsay, A J; Ferguson, A J

    2016-01-01

    An enhancement in Brillouin light scattering of optical photons with magnons is demonstrated in magneto-optical whispering gallery mode resonators tuned to a triple resonance point. This occurs when both the input and output optical modes are resonant with those of the whispering gallery resonator, with a separation given by the ferromagnetic resonance (FMR) frequency. The identification and excitation of specific optical modes allows us to gain a clear understanding of the mode-matching conditions. A selection rule due to wavevector matching leads to an intrinsic single-sideband excitation. Strong suppression of one sideband is essential for one-to-one frequency mapping in coherent optical-to-microwave conversion.

  6. Tuning of Detection Wavelength in a Resonant-Cavity-Enhanced Quantum-Dot-Embedded Photodiode by Changing Detection Angle

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hao; ZHU Hui; ZHENG Hou-Zhi; XU Ping; PENG Hong-Ling; TAN Ping-Heng; YANG Fu-Hua; NI Hai-Qiao; ZENG Yu-Xin; GAN Hua-Dong

    2005-01-01

    @@ We have Fabricated a resonant-cavity-enhanced photodiode (RCE-PD) with InGaAs quantum dots (QDs) as an active medium. This sort of QD-embedded RCE-PD is capable of a peak external quantum efficiency of 32%and responsivity of 0.27 A/W at 1.058 μm with a full width at half maximum (FWHM) of 5nm. Angle-resolved photocurrent response eventually proves that with the detection angle changing from 0° to 60°, the peak-current wavelength shifts towards the short wavelength side by 37nm, while the quantum efficiency remains larger than 15%.

  7. Low cost low phase noise PLL controlled push-push VCOs in k- and ka- bands, stabilized by cavity resonator

    OpenAIRE

    Tsvelykh, I. S.; B. A. Kotserzhynskyi

    2016-01-01

    This work demonstrates push-push VCOs in K-band (with second harmonic output at 24 GHz) and in Ka-band (with third harmonic output at 36 GHz), and PLL synthesizers on their basis. Oscillators are stabilized by a rectangular resonant metallic cavity. Output signal power within the frequency tuning range changes in the limits of -11,5 -7,6 dBm and -11,8 -10,9 dBm for 24 GHz and 36 GHz oscillators respectively. Single sideband (SSB) phase noise spectral densities of -91 dBc/Hz for 24 GHz oscilla...

  8. A multi-atom and resonant interaction scheme for quantum state transfer and logical gates between two remote cavities via an optical fibre

    CERN Document Server

    Yin, Z; Yin, Zhang-qi; Li, Fu-li

    2007-01-01

    A system consisting of two single-mode cavities spatially separated and connected by an optical fibre and multi two-level atoms trapped in the cavities is considered. If the atoms resonantly and collectively interact with the local cavity fields but there is no direct interaction between the atoms, we show that an ideal quantum state transfer, and highly reliable quantum swap, entangling and controlled-Z gates can be deterministically realized between the distant cavities. We find that the operation of the state-transfer, and swap, entangling and controlled-Z gates can be greatly speeded up as number of the atoms in the cavities increases. We also notice that the effects of spontaneous emission of atoms and photon leakage out of cavity on the quantum processes can also be greatly diminished in the multi-atom case.

  9. Fano-resonance boosted cascaded field enhancement in a plasmonic nanoparticle-in-cavity nanoantenna array and its SERS application

    CERN Document Server

    Zhu, Zhendong; You, Oubo; Li, Qunqing; Fan, Shoushan

    2015-01-01

    Cascaded optical field enhancement (CFE) can be realized in some specially designed multiscale plasmonic nanostructures, where the generation of extremely strong field at nanoscale volume is crucial for many applications, for example, surface enhanced Raman spectroscopy (SERS). Here, we propose a strategy of realizing a high-quality plasmonic nanoparticle-in-cavity (PIC) nanoantenna array, where strong coupling between a nanoparticle dark mode with a high order nanocavity bright mode can produce Fano resonance at a target wavelength. The Fano resonance can effectively boost the CFE in the PIC, with a field enhancement factor up to 5X10^2. A cost-effective and reliable nanofabrication method is developed with room temperature nanoimprinting lithography to manufacture high-quality PIC arrays. This technique guarantees the generation of only one gold nanoparticle at the bottom of each nanocavity, which is crucial for the generation of the expected CFE. As a demonstration of the performance and application of the...

  10. Nonlinear resonance phenomena of a doped fibre laser under cavity-loss modulation: Experimental demonstrations

    Indian Academy of Sciences (India)

    A Ghosh; B K Goswami; R Vijaya

    2010-11-01

    Our experiments with an erbium-doped fibre ring laser (CW, single transverse mode and multiaxial mode) with an intracavity LiNbO3 electro-optic modulator (EOM) display the characteristic features of a nonlinear oscillator (e.g., harmonic and period-2 sub-harmonic resonances) when the EOM driver voltage is modulated periodically. Harmonic resonance leads to period-1 bistability and hysteresis. Inside the period-2 sub-harmonic resonance region, the laser exhibits Feigenbaum sequence and generalized bistability.

  11. Dynamic control of the asymmetric Fano resonance in side-coupled Fabry–Pérot and photonic crystal nanobeam cavities

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Tong; Chau, Fook Siong; Zhou, Guangya, E-mail: mpezgy@nus.edu.sg [Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576 (Singapore); Deng, Jie [Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602 (Singapore)

    2015-11-30

    Fano resonance is a prevailing interference phenomenon that stems from the intersection between discrete and continuum states in many fields. We theoretically and experimentally characterize the asymmetric Fano lineshape in side-coupled waveguide Fabry–Pérot and photonic crystal nanobeam cavities. The measured quality-factor of the Fano resonance before tuning is 28 100. A nanoelectromechanical systems bidirectional actuator is integrated seamlessly to control the shape of the Fano resonance through in-plane translations in two directions without sacrificing the quality-factor. The peak intensity level of the Fano resonance can be increased by 8.5 dB from 60 nW to 409 nW while the corresponding dip intensity is increased by 12.8 dB from 1 nW to 18 nW. The maximum recorded quality-factor throughout the tuning procedure is up to 32 500. Potential applications of the proposed structure include enhancing the sensitivity of sensing, reconfigurable nanophotonics devices, and on-chip intensity modulator.

  12. A case study on the ELF characterization of the Earth ionosphere cavity: Forecasting the Schumann resonance intensities

    Science.gov (United States)

    Tulunay, Y.; Altuntas, E.; Tulunay, E.; Price, C.; Ciloglu, T.; Bahadirlar, Y.; Senalp, E. T.

    2008-02-01

    Schumann Resonances (SR) are the electromagnetic (EM) phenomena which occur in the cavity formed by the conducting Earth and the ionosphere, with peak mode frequencies close to 8, 14, 20, 26, 32 Hz, etc. [Price, C., Melnikov, A., 2004. Diurnal, seasonal and inter-annual variations in the Schumann resonance parameters. Journal of Atmospheric and Solar-Terrestrial Physics 66, 1179-1185]. The spectral characteristics of the SR modes are defined by their resonant mode amplitudes, center frequencies and half-widths [Price, C., Melnikov, A., 2004. Diurnal, seasonal and inter-annual variations in the Schumann resonance parameters. Journal of Atmospheric and Solar-Terrestrial Physics 66, 1179-1185]. The objective of this work is two fold: (i) to investigate the characteristics of SR parameters obtained at Sarköy in Turkey and (ii) to model the dynamical characteristics of the SR processes by forecasting the first SR mode power values using a neural network (NN) model. The NN model is revised version of the METUNN [Tulunay, Y., Tulunay, E., Senalp, E.T., 2004a. The neural network technique--1: a general exposition. Advances in Space Research 33, 983-987].

  13. Controllable optical response by modifying the gain and loss of a mechanical resonator and cavity mode in an optomechanical system

    Science.gov (United States)

    Liu, Yu-Long; Wu, Rebing; Zhang, Jing; Özdemir, Şahin Kaya; Yang, Lan; Nori, Franco; Liu, Yu-xi

    2017-01-01

    We theoretically study a strongly driven optomechanical system which consists of a passive optical cavity and an active mechanical resonator. When the optomechanical coupling strength is varied, phase transitions, which are similar to those observed in PT -symmetric systems, are observed. We show that the optical transmission can be controlled by changing the gain of the mechanical resonator and loss of the optical cavity mode. Especially, we find that (i) for balanced gain and loss, optical amplification and absorption can be tuned by changing the optomechanical coupling strength through a control field; (ii) for unbalanced gain and loss, even with a tiny mechanical gain, both optomechanically induced transparency and anomalous dispersion can be observed around a critical point, which exhibits an ultralong group delay. The time delay τ can be optimized by regulating the optomechanical coupling strength through the control field, and it can be improved up to several orders of magnitude (τ ˜2 ms ) compared to that of conventional optomechanical systems (τ ˜1 μ s ). The presence of mechanical gain makes the group delay more robust to environmental perturbations. Our proposal provides a powerful platform to control light transport using a PT -symmetric-like optomechanical system.

  14. Linewidth broadening and emission saturation of a resonantly excited quantum dot monitored via an off-resonant cavity mode

    DEFF Research Database (Denmark)

    Ulhaq, A.; Ates, Serkan; Weiler, S.;

    2010-01-01

    We report on the robustness of a detuned mode channel for reading out the relevant s-shell properties of a resonantly excited coupled quantum dot (QD) in a pillar microcavity. The line broadening of the QD s-shell is “monitored” by the mode signal with high conformity to the directly measured QD ...

  15. Frequency dependence of the microwave surface resistance of MgB{sub 2} by coaxial cavity resonator

    Energy Technology Data Exchange (ETDEWEB)

    Agliolo Gallitto, A., E-mail: aurelio.agliologallitto@unipa.it [CNISM and Dipartimento di Fisica e Chimica, Università di Palermo, via Archirafi 36, 90123 Palermo (Italy); Camarda, P.; Li Vigni, M. [CNISM and Dipartimento di Fisica e Chimica, Università di Palermo, via Archirafi 36, 90123 Palermo (Italy); Figini Albisetti, A. [EDISON SpA Research and Development Division, Foro Buonaparte 31, 20121 Milano (Italy); Giunchi, G. [Freelance Consultant, via Teodosio 8, 20131 Milano (Italy)

    2014-08-15

    Highlights: • We investigate the microwave properties of a bulk MgB{sub 2} rod 94.3 mm long. • The MgB{sub 2} rod is used as inner conductor of a coaxial cavity. • The mw surface resistance vs. frequency is studied in the range 1–9 GHz. • R{sub s} vs. f curves follow a f{sup n} law, with n decreasing with the temperature. • Deviations from the quadratic law are highlighted at relatively low temperatures. - Abstract: We report on the microwave (mw) properties of a cylindrical MgB{sub 2} rod prepared by the reactive liquid Mg infiltration technology. The MgB{sub 2} rod, 94.3 mm long, is used as inner conductor of a coaxial cavity having a Cu tube as external conductor. By analyzing the resonance curves of the cavity in the different resonant modes and at different temperatures, we have determined the temperature dependence of the mw surface resistance, R{sub s}, of the MgB{sub 2} material, at fixed frequencies, and the frequency dependence of R{sub s}, at fixed temperatures. Our results show that the R{sub s}(f) curves follow a f{sup n} law, where n decreases on increasing the temperature, starting from n≈2, at T=4.2K, down to n≈0.7 at T⩾T{sub c}. The double-gap nature of MgB{sub 2} manifests itself in the presence of a wide low-T tail in the R{sub s}(T) curves, which can be ascribed to the quasiparticles thermally excited through the π gap even at relatively low temperatures.

  16. Fiber ring resonator with nanofiber section for chiral cavity quantum electrodynamics and multimode strong coupling

    CERN Document Server

    Schneeweiss, Philipp; Hoinkes, Thomas; Rauschenbeutel, Arno; Volz, Jürgen

    2016-01-01

    We experimentally realize an optical fiber ring resonator that includes a tapered section with subwavelength-diameter waist. In this section, the guided light exhibits a significant evanescent field which allows for efficient interfacing with optical emitters. A commercial tunable fiber beam splitter provides simple and robust coupling to the resonator. Key parameters of the resonator such as its out-coupling rate, free spectral range, and birefringence can be adjusted. Thanks to the low taper- and coupling-losses, the resonator exhibits an unloaded finesse of F=75+/-1, sufficient for reaching the regime of strong coupling for emitters placed in the evanescent field. The system is ideally suited for trapping ensembles of laser-cooled atoms along the nanofiber section. Based on measured parameters, we estimate that the system can serve as a platform for optical multimode strong coupling experiments. Finally, we discuss the possibilities of using the resonator for applications based on chiral quantum optics.

  17. Aperiodic signals processing via parameter-tuning stochastic resonance in a photorefractive ring cavity

    Directory of Open Access Journals (Sweden)

    Xuefeng Li

    2014-04-01

    Full Text Available Based on solving numerically the generalized nonlinear Langevin equation describing the nonlinear dynamics of stochastic resonance by Fourth-order Runge-Kutta method, an aperiodic stochastic resonance based on an optical bistable system is numerically investigated. The numerical results show that a parameter-tuning stochastic resonance system can be realized by choosing the appropriate optical bistable parameters, which performs well in reconstructing aperiodic signals from a very high level of noise background. The influences of optical bistable parameters on the stochastic resonance effect are numerically analyzed via cross-correlation, and a maximum cross-correlation gain of 8 is obtained by optimizing optical bistable parameters. This provides a prospective method for reconstructing noise-hidden weak signals in all-optical signal processing systems.

  18. Aperiodic signals processing via parameter-tuning stochastic resonance in a photorefractive ring cavity

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xuefeng, E-mail: lixfpost@163.com [School of Science, Xi' an University of Post and Telecommunications, Xi' an, 710121 (China); Cao, Guangzhan; Liu, Hongjun [Xi' an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi' an, 710119 (China)

    2014-04-15

    Based on solving numerically the generalized nonlinear Langevin equation describing the nonlinear dynamics of stochastic resonance by Fourth-order Runge-Kutta method, an aperiodic stochastic resonance based on an optical bistable system is numerically investigated. The numerical results show that a parameter-tuning stochastic resonance system can be realized by choosing the appropriate optical bistable parameters, which performs well in reconstructing aperiodic signals from a very high level of noise background. The influences of optical bistable parameters on the stochastic resonance effect are numerically analyzed via cross-correlation, and a maximum cross-correlation gain of 8 is obtained by optimizing optical bistable parameters. This provides a prospective method for reconstructing noise-hidden weak signals in all-optical signal processing systems.

  19. Theoretical estimates of maximum fields in superconducting resonant radio frequency cavities: Stability theory, disorder, and laminates

    CERN Document Server

    Liarte, Danilo B; Transtrum, Mark K; Catelani, Gianluigi; Liepe, Matthias; Sethna, James P

    2016-01-01

    We review our work on theoretical limits to the performance of superconductors in high magnetic fields parallel to their surfaces. These limits are of key relevance to current and future accelerating cavities, especially those made of new higher-$T_c$ materials such as Nb$_3$Sn, NbN, and MgB$_2$. We summarize our calculations of the so-called superheating field $H_{\\mathrm{sh}}$, beyond which flux will spontaneously penetrate even a perfect superconducting surface and ruin the performance. We briefly discuss experimental measurements of the superheating field, comparing to our estimates. We explore the effects of materials anisotropy and disorder. Will we need to control surface orientation in the layered compound MgB$_2$? Can we estimate theoretically whether dirt and defects make these new materials fundamentally more challenging to optimize than niobium? Finally, we discuss and analyze recent proposals to use thin superconducting layers or laminates to enhance the performance of superconducting cavities. T...

  20. An Investigation of Cavity Resonance and its Relationship to Store Force and Moment Loading

    Science.gov (United States)

    2011-03-01

    13 2.3.3 Overset Grids . . . . . . . . . . . . . . . . . . . 16 2.4 Signal Processing and Spectral Analysis ...fluctuating flow present in the region of a weapon bay. Additionally, it was common practice to use high ejector forces in order to release the store at high... ejector forces that can be used. Much of the early research in the area of cavity flows focused on the acoustic modes as it related to structural fatigue in

  1. Ground-state cooling of a nanomechanical resonator via single-polariton optomechanics in a coupled quantum-dot-cavity system

    Science.gov (United States)

    Zhou, Ben-yuan; Li, Gao-xiang

    2016-09-01

    We propose a rapid ground-state optomechanical cooling scheme in a hybrid system, where a two-level quantum dot (QD) is placed in a single-mode cavity and a nanomechanical resonator (NMR) is also coupled to the cavity via radiation pressure. The cavity is driven by a weak laser field while the QD is driven by another weak laser field. Due to the quantum destructive interference arisen from different transition channels induced by simultaneously driving the QD-cavity system in terms of the two different lasers, two-photon absorption for the cavity field can be effectively eliminated by performing an optimal quantum interference condition. Furthermore, it is demonstrated that the QD-cavity system can be unbalancedly prepared in two single-polariton states with different eigenenergies. If the frequency of the NMR is tuned to be resonant with transition between two single-polariton states, it is found that a fast ground-state cooling for the NMR can also be achieved, even when the QD-cavity system is originally in the moderate-coupling regime. Thus the present ground-state cooling scheme for the NMR may be realized with currently available experimental technology.

  2. Three-dimensional cavity nanoantennas with resonant-enhanced surface plasmons as dynamic color-tuning reflectors.

    Science.gov (United States)

    Fan, J R; Wu, W G; Chen, Z J; Zhu, J; Li, J

    2017-03-09

    As plasmonic antennas for surface-plasmon-assisted control of optical fields at specific frequencies, metallic nanostructures have recently emerged as crucial optical components for fascinating plasmonic color engineering. Particularly, plasmonic resonant nanocavities can concentrate lightwave energy to strongly enhance light-matter interactions, making them ideal candidates as optical elements for fine-tuning color displays. Inspired by the color mixing effect found on butterfly wings, a new type of plasmonic, multiresonant, narrow-band (the minimum is about 45 nm), high-reflectance (the maximum is about 95%), and dynamic color-tuning reflector is developed. This is achieved from periodic patterns of plasmonic resonant nanocavities in free-standing capped-pillar nanostructure arrays. Such cavity-coupling structures exhibit multiple narrow-band selective and continuously tunable reflections via plasmon standing-wave resonances. Consequently, they can produce a variety of dark-field vibrant reflective colors with good quality, strong color signal and fine tonal variation at the optical diffraction limit. This proposed multicolor scheme provides an elegant strategy for realizing personalized and customized applications in ultracompact photonic data storage and steganography, colorimetric sensing, 3D holograms and other plasmon-assisted photonic devices.

  3. PRODUCTION OF SOUND BY UNSTEADY THROTTLING OF FLOW INTO A RESONANT CAVITY, WITH APPLICATION TO VOICED SPEECH.

    Science.gov (United States)

    Howe, M S; McGowan, R S

    2011-04-01

    An analysis is made of the sound generated by the time-dependent throttling of a nominally steady stream of air through a small orifice into a flow-through resonant cavity. This is exemplified by the production of voiced speech, where air from the lungs enters the vocal tract through the glottis at a time variable volume flow rate Q(t) controlled by oscillations of the glottis cross-section. Voicing theory has hitherto determined Q from a heuristic, reduced complexity 'Fant' differential equation (G. Fant, Acoustic Theory of Speech Production, 1960). A new self-consistent, integro-differential form of this equation is derived in this paper using the theory of aerodynamic sound, with full account taken of the back-reaction of the resonant tract on the glottal flux Q. The theory involves an aeroacoustic Green's function (G) for flow-surface interactions in a time-dependent glottis, so making the problem non-self-adjoint. In complex problems of this type it is not usually possible to obtain G in an explicit analytic form. The principal objective of the paper is to show how the Fant equation can still be derived in such cases from a consideration of the equation of aerodynamic sound and from the adjoint of the equation governing G in the neighbourhood of the 'throttle'. The theory is illustrated by application to the canonical problem of throttled flow into a Helmholtz resonator.

  4. Ovenized microelectromechanical system (MEMS) resonator

    Science.gov (United States)

    Olsson, Roy H; Wojciechowski, Kenneth; Kim, Bongsang

    2014-03-11

    An ovenized micro-electro-mechanical system (MEMS) resonator including: a substantially thermally isolated mechanical resonator cavity; a mechanical oscillator coupled to the mechanical resonator cavity; and a heating element formed on the mechanical resonator cavity.

  5. Formation of long-lived resonances in hexagonal cavities by strong coupling of superscar modes

    Science.gov (United States)

    Song, Qinghai; Ge, Li; Wiersig, Jan; Cao, Hui

    2013-08-01

    The recent progresses in single crystalline wide bandgap hexagonal disk have stimulated intense research attention on pursuing ultraviolet (UV) laser diodes with low thresholds. While whispering-gallery modes based UV lasers have been successfully obtained in GaN, ZnO nanorods, and nanopillars, the reported thresholds are still very high, due to the low-quality (Q) factors of the hexagonal resonances. Here we demonstrate resonances whose Q factors can be more than two orders of magnitude higher than the hexagonal modes, promising the reduction of the energy consumption. The key to our finding is the avoided resonance crossing between superscar states along two sets of nearly degenerated triangle orbits, which leads to the formation of hexagram modes. The mode couplings suppress the field distributions at the corners and the deviations from triangle orbits simultaneously and therefore enhance the Q factors significantly.

  6. Circuit-tunable sub-wavelength THz resonators: hybridizing optical cavities and loop antennas.

    Science.gov (United States)

    Paulillo, B; Manceau, J M; Degiron, A; Zerounian, N; Beaudoin, G; Sagnes, I; Colombelli, R

    2014-09-08

    We demonstrate subwavelength electromagnetic resonators operating in the THz spectral range, whose spectral properties and spatial/angular patterns can be engineered in a similar way to an electronic circuit. We discuss the device concept, and we experimentally study the tuning of the resonant frequency as a function of variable capacitances and inductances. We then elucidate the optical coupling properties. The radiation pattern, obtained by angle-resolved reflectance, reveals that the system mainly couples to the outside world via a magnetic dipolar interaction.

  7. Two-Qubit Geometric Phase Gate for Quantum Dot Spins using Cavity Polariton Resonance

    CERN Document Server

    Puri, Shruti; Yamamoto, Yoshihisa

    2012-01-01

    We describe a design to implement a two-qubit geometric phase gate, by which a pair of electrons confined in adjacent quantum dots are entangled. The entanglement is a result of the Coulomb exchange interaction between the optically excited exciton-polaritons and the localized spins. This optical coupling, resembling the electron-electron Ruderman-Kittel-Kasuya-Yosida (RKKY) inter- actions, offers high speed, high fidelity two-qubit gate operation with moderate cavity quality factor Q. The errors due to the finite lifetime of the polaritons can be minimized by optimizing the optical pulse parameters (duration and energy). The proposed design, using electrostatic quantum dots, maximizes entanglement and ensures scalability.

  8. Study of thermal conductivity of magnetorheological fluids using the thermal-wave resonant cavity and its relationship with the viscosity

    Science.gov (United States)

    Forero-Sandoval, I. Y.; Vega-Flick, A.; Alvarado-Gil, J. J.; Medina-Esquivel, R. A.

    2017-02-01

    The thermal conductivity and viscosity of a magnetorheological suspension composed of carbonyl iron particles immerse in silicone oil were studied. Thermal wave resonant cavity was employed to measure the thermal diffusivity of the magnetorheological fluid as a function of an externally applied magnetic field. The dynamic viscosity was also measured and its relationship with the concentration of the particles and the magnetic field strength was investigated. The results show that higher concentrations of carbonyl iron particles as well as higher magnetic field intensities lead to a significant increase in thermal conductivity. The relationship between the thermal conductivity and the dynamic viscosity was explored. Our measurements were examined using an analytical relation between the thermal conductivity and the dynamic viscosity. The results show that by using highly viscous materials, the order induced in the micro particles can be kept for a relatively long time and therefore the increase in thermal conductivity can also be maintained.

  9. Cavity quantum electrodynamics using a near-resonance two-level system: Emergence of the Glauber state

    Energy Technology Data Exchange (ETDEWEB)

    Sarabi, B.; Ramanayaka, A. N. [Laboratory for Physical Sciences, College Park, Maryland 20740 (United States); Department of Physics, University of Maryland, College Park, Maryland 20742 (United States); Burin, A. L. [Department of Chemistry, Tulane University, New Orleans, Louisiana 70118 (United States); Wellstood, F. C. [Department of Physics, University of Maryland, College Park, Maryland 20742 (United States); Joint Quantum Institute, University of Maryland, College Park, Maryland 20742 (United States); Osborn, K. D. [Laboratory for Physical Sciences, College Park, Maryland 20740 (United States); Joint Quantum Institute, University of Maryland, College Park, Maryland 20742 (United States)

    2015-04-27

    Random tunneling two-level systems (TLSs) in dielectrics have been of interest recently because they adversely affect the performance of superconducting qubits. The coupling of TLSs to qubits has allowed individual TLS characterization, which has previously been limited to TLSs within (thin) Josephson tunneling barriers made from aluminum oxide. Here, we report on the measurement of an individual TLS within the capacitor of a lumped-element LC microwave resonator, which forms a cavity quantum electrodynamics (CQED) system and allows for individual TLS characterization in a different structure and material than demonstrated with qubits. Due to the reduced volume of the dielectric (80 μm{sup 3}), even with a moderate dielectric thickness (250 nm), we achieve the strong coupling regime as evidenced by the vacuum Rabi splitting observed in the cavity spectrum. A TLS with a coherence time of 3.2 μs was observed in a film of silicon nitride as analyzed with a Jaynes-Cummings spectral model, which is larger than seen from superconducting qubits. As the drive power is increased, we observe an unusual but explicable set of continuous and discrete crossovers from the vacuum Rabi split transitions to the Glauber (coherent) state.

  10. Electromagnetic wave properties of polymer blends of single wall carbon nanotubes using a resonant microwave cavity as a probe

    Science.gov (United States)

    Roberts, J. A.; Imholt, T.; Ye, Z.; Dyke, C. A.; Price, D. W.; Tour, J. M.

    2004-04-01

    A resonant microwave cavity operating in the TM010 mode was used to determine the microwave susceptibility of single walled carbon nanotubes (SWNT) that are blended in polymer matricies. The frequencies of the probe signal were 9.8, 11.4, and 35.93 GHz. Samples of 3%-19% blends of SWNT in polycarbonate were tested to determine the best blends for shielding of devices from microwaves at these frequencies. It appears that blends of 9%-11% are very effective in shielding the electric vector of electromagnetic waves. Both the electric vector and the magnetic vectors were probed by the process to determine the nature of coupling between the SWNTs and the applied fields. Some details are given about the apparatus design that enables computer collection and processing of the data to be achieved. An electronic differentiation technique was used to allow the second derivative of the cavity absorption profile to be displayed for precise measurement. Data are presented to show the relative microwave absorption for different blends of the SWNTs with polycarbonates.

  11. Cavity quantum electrodynamics using a near-resonance two-level system: Emergence of the Glauber state

    Science.gov (United States)

    Sarabi, B.; Ramanayaka, A. N.; Burin, A. L.; Wellstood, F. C.; Osborn, K. D.

    2015-04-01

    Random tunneling two-level systems (TLSs) in dielectrics have been of interest recently because they adversely affect the performance of superconducting qubits. The coupling of TLSs to qubits has allowed individual TLS characterization, which has previously been limited to TLSs within (thin) Josephson tunneling barriers made from aluminum oxide. Here, we report on the measurement of an individual TLS within the capacitor of a lumped-element LC microwave resonator, which forms a cavity quantum electrodynamics (CQED) system and allows for individual TLS characterization in a different structure and material than demonstrated with qubits. Due to the reduced volume of the dielectric (80 μm3), even with a moderate dielectric thickness (250 nm), we achieve the strong coupling regime as evidenced by the vacuum Rabi splitting observed in the cavity spectrum. A TLS with a coherence time of 3.2 μs was observed in a film of silicon nitride as analyzed with a Jaynes-Cummings spectral model, which is larger than seen from superconducting qubits. As the drive power is increased, we observe an unusual but explicable set of continuous and discrete crossovers from the vacuum Rabi split transitions to the Glauber (coherent) state.

  12. Resonant enhancement of the zero-phonon emission from a color center in a diamond cavity

    CERN Document Server

    Faraon, Andrei; Santori, Charles; Fu, Kai-Mei C; Beausoleil, Raymond G

    2010-01-01

    We demonstrate coupling of the zero-phonon line of individual nitrogen-vacancy centers and the modes of microring resonators fabricated in single-crystal diamond. A zero-phonon line enhancement exceeding ten-fold is estimated from lifetime measurements at cryogenic temperatures. The devices are fabricated using standard semiconductor techniques and off-the-shelf materials, thus enabling integrated diamond photonics.

  13. Multi circular-cavity surface coil for magnetic resonance imaging of monkey's brain at 4 Tesla

    Science.gov (United States)

    Osorio, A. I.; Solis-Najera, S. E.; Vázquez, F.; Wang, R. L.; Tomasi, D.; Rodriguez, A. O.

    2014-11-01

    Animal models in medical research has been used to study humans diseases for several decades. The use of different imaging techniques together with different animal models offers a great advantage due to the possibility to study some human pathologies without the necessity of chirurgical intervention. The employ of magnetic resonance imaging for the acquisition of anatomical and functional images is an excellent tool because its noninvasive nature. Dedicated coils to perform magnetic resonance imaging experiments are obligatory due to the improvement on the signal-to-noise ratio and reduced specific absorption ratio. A specifically designed surface coil for magnetic resonance imaging of monkey's brain is proposed based on the multi circular-slot coil. Numerical simulations of the magnetic and electric fields were also performed using the Finite Integration Method to solve Maxwell's equations for this particular coil design and, to study the behavior of various vector magnetic field configurations and specific absorption ratio. Monkey's brain images were then acquired with a research-dedicated magnetic resonance imaging system at 4T, to evaluate the anatomical images with conventional imaging sequences. This coil showed good quality images of a monkey's brain and full compatibility with standard pulse sequences implemented in research-dedicated imager.

  14. Resonant cavities for efficient LT-GaAs photoconductors operating at λ = 1550 nm

    Science.gov (United States)

    Billet, M.; Latzel, P.; Pavanello, F.; Ducournau, G.; Lampin, J.-F.; Peytavit, E.

    2016-10-01

    We show that photoconductors based on low-temperature-grown GaAs (LT-GaAs) can be efficiently operated by 1.55 μm telecom wavelength by using metallic mirror based optical cavities. Two different semi-transparent front mirrors are compared: the first one is a thin gold layer, whereas the second one consists of a gold grating. Light absorption in grating mirror based optical cavities is numerically, analytically, and experimentally investigated allowing for an appropriate optical design. We show a 3 times improvement of the LT-GaAs photoconductor photoresponse by using, as front mirror, the gold grating once compared with the thin gold layer. It reaches around 0.5 mA/W under continuous wave, whereas a transient photoresistivity (Ron) as low as 5 Ω is deduced from dc photocurrents measured under femtosecond pulsed laser excitation. This work paves the way to efficient and reliable optoelectronics systems for GHz or THz waves sampling driven by 1.55 μm pulsed lasers widely available.

  15. Resonant cavities for efficient LT-GaAs photoconductors operating at λ = 1550 nm

    Directory of Open Access Journals (Sweden)

    M. Billet

    2016-10-01

    Full Text Available We show that photoconductors based on low-temperature-grown GaAs (LT-GaAs can be efficiently operated by 1.55 μm telecom wavelength by using metallic mirror based optical cavities. Two different semi-transparent front mirrors are compared: the first one is a thin gold layer, whereas the second one consists of a gold grating. Light absorption in grating mirror based optical cavities is numerically, analytically, and experimentally investigated allowing for an appropriate optical design. We show a 3 times improvement of the LT-GaAs photoconductor photoresponse by using, as front mirror, the gold grating once compared with the thin gold layer. It reaches around 0.5 mA/W under continuous wave, whereas a transient photoresistivity (Ron as low as 5 Ω is deduced from dc photocurrents measured under femtosecond pulsed laser excitation. This work paves the way to efficient and reliable optoelectronics systems for GHz or THz waves sampling driven by 1.55 μm pulsed lasers widely available.

  16. Theoretical estimates of maximum fields in superconducting resonant radio frequency cavities: stability theory, disorder, and laminates

    Science.gov (United States)

    Liarte, Danilo B.; Posen, Sam; Transtrum, Mark K.; Catelani, Gianluigi; Liepe, Matthias; Sethna, James P.

    2017-03-01

    Theoretical limits to the performance of superconductors in high magnetic fields parallel to their surfaces are of key relevance to current and future accelerating cavities, especially those made of new higher-T c materials such as Nb3Sn, NbN, and MgB2. Indeed, beyond the so-called superheating field {H}{sh}, flux will spontaneously penetrate even a perfect superconducting surface and ruin the performance. We present intuitive arguments and simple estimates for {H}{sh}, and combine them with our previous rigorous calculations, which we summarize. We briefly discuss experimental measurements of the superheating field, comparing to our estimates. We explore the effects of materials anisotropy and the danger of disorder in nucleating vortex entry. Will we need to control surface orientation in the layered compound MgB2? Can we estimate theoretically whether dirt and defects make these new materials fundamentally more challenging to optimize than niobium? Finally, we discuss and analyze recent proposals to use thin superconducting layers or laminates to enhance the performance of superconducting cavities. Flux entering a laminate can lead to so-called pancake vortices; we consider the physics of the dislocation motion and potential re-annihilation or stabilization of these vortices after their entry.

  17. Optimization of a hot-cavity type resonant ionization laser ion source

    Energy Technology Data Exchange (ETDEWEB)

    Henares, J. L., E-mail: henares@ganil.fr; Lecesne, N.; Hijazi, L.; Bastin, B.; Leroy, R.; Osmond, B.; Vignet, J. L. [GANIL, BP 55027, 14076 Caen Cedex 5 (France); Kron, T.; Naubereit, P.; Wendt, K. [Johannes Gutenberg-Universität Mainz, Staudinger Weg 7, 55099 Mainz (Germany); Lassen, J. [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3 (Canada); Le Blanc, F. [IPN Orsay, BP 1-91406 Orsay (France)

    2016-02-15

    Resonant Ionization Laser Ion Source (RILIS) is nowadays an important technique in many Radioactive Ion Beam (RIB) facilities for its reliability and ability to ionize efficiently and element selectively. Grand Accélérateur National d’Ions Lourds (GANIL) Ion Source using Electron Laser Excitation (GISELE) is an off-line test bench for RILIS developed to study a fully operational resonant laser ion source at GANIL facility. The ion source body has been designed as a modular system to investigate different experimental approaches by varying the design parameters, to develop the future on-line laser ion source. The aim of this project is to determine the best technical solution which combines high selectivity and ionization efficiency with small ion beam emittance and stable long term operation. Latest results concerning emittance and time profile development as a function of the temperature for different ion source versions will be presented.

  18. Influence of Intrinsic Decoherence on Entanglement of Superconducting Charge Qubit in a Resonant Cavity

    Institute of Scientific and Technical Information of China (English)

    LIU Xiao-Nan; SHAO Bin; ZOU Jian

    2005-01-01

    @@ Taking the intrinsic decoherence effect into account, we investigate the entanglement dynamics of a superconducting charge qubit in a single-mode optical cavity. Concurrence, as the measure of entanglement of the coupled field-junction system, is calculated. In comparison, we also consider the entanglement of the system by using the entanglement parameter based on the ratio between mutual entropy and partial Von-Neumann entropy to investigate how the intrinsic decoherence affects the entanglement of the coupling system. Our results show that the evolution of the entanglement parameter has the behaviour similar to the concurrence and it is thus the well measure of entanglement for the mixed state in such a coupling system.

  19. Diagnostic value of magnetic resonance lymphography in preoperative staging of clinically negative necks in squamous cell carcinoma of the oral cavity: A pilot study

    NARCIS (Netherlands)

    Wensing, B.M.; Deserno, W.M.L.L.G.; Bondt, R.B. de; Marres, H.A.M.; Merkx, M.A.W.; Barentsz, J.O.; Hoogen, F.J. van den

    2011-01-01

    Pilot study evaluating the diagnostic value of magnetic resonance lymphography (MRL) compared with conventional imaging techniques in the preoperative staging of the clinically (palpable) negative neck (cN0) in squamous cell carcinoma of the oral cavity (SCCOC). Patients with SCCOC without clinical

  20. Standing-wave resonances in plasmonic nanoumbrella cavities for color generation and colorimetric refractive index sensor

    Science.gov (United States)

    Fan, Jiaorong; Li, Zhongyuan; Chen, Zhuojie; Wu, Wengang

    2016-10-01

    We theoretically investigate the hybridization of the elemental surface plasmons in umbrella-shape plasmonic nanostructures and experimentally demonstrate the implementation of plasmonic multicolor metasurfaces as well as their application in colorimetric sensing. The three-dimension metallic umbrella arrays consist of a periodic canopy-capped-nanopillars with metal-coated sidewall and a backplane metal-film to form vertical nanocavity of canopy and film. Plasmonic coupling and energy confinement in nanocavity induce a noticeably resonance narrowing of multispectral reflection. The metasurfaced nanostructures appeared in vibrant and tunable colors with broad gamut derived from color blending mechanism due to multiple, narrow-band resonances. Vivid colors varied from red, yellow, green, blue to violet are easily achieved. It is also shown that such plasmonic metasurfaces can work as the feasible and real-time colorimetric refractive index sensor by measuring the distinct color variation to glucose concentration changes. Our sensor scheme shows its spectral sensitivity in the periodic umbrella array with respect to the refractive index change to be 242.5 nm/RIU with a figure of merit of 7.3. Furthermore, a refractive index resolution of colorimetric sensing up to 0.025 RIU has been accomplished.

  1. Ionizing Radiation Detectors Based on Ge-Doped Optical Fibers Inserted in Resonant Cavities

    Directory of Open Access Journals (Sweden)

    Saverio Avino

    2015-02-01

    Full Text Available The measurement of ionizing radiation (IR is a crucial issue in different areas of interest, from environmental safety and industrial monitoring to aerospace and medicine. Optical fiber sensors have recently proven good candidates as radiation dosimeters. Here we investigate the effect of IR on germanosilicate optical fibers. A piece of Ge-doped fiber enclosed between two fiber Bragg gratings (FBGs is irradiated with gamma radiation generated by a 6 MV medical linear accelerator. With respect to other FBG-based IR dosimeters, here the sensor is only the bare fiber without any special internal structure. A near infrared laser is frequency locked to the cavity modes for high resolution measurement of radiation induced effects on the fiber optical parameters. In particular, we observe a variation of the fiber thermo-optic response with the radiation dose delivered, as expected from the interaction with Ge defect centers, and demonstrate a detection limit of 360 mGy. This method can have an impact in those contexts where low radiation doses have to be measured both in small volumes or over large areas, such as radiation therapy and radiation protection, while bare optical fibers are cheap and disposable.

  2. Compound cavity theory of resonant phase modulation in laser self-mixing ultrasonic vibration measurement

    Science.gov (United States)

    Tao, Yufeng; Wang, Ming; Guo, Dongmei

    2016-07-01

    The theoretical basis of self-mixing interference (SMI) employing a resonant phase modulator is explored to prove its tempting advantages. The adopted method induces a pure phase carrier without increasing system complexity. A simple time-domain signal process is used to estimate modulation depth and precisely track vibrating trail, which promises the flexibility of measuring ultrasonic vibration regardless of the constraint of the Bessel functions. The broad bandwidth, low speckle noise, compact, safe, and easy operating SMI system obtains the best resolution of a poor reflection environment. Numerical simulation discusses the spectrum broadening and errors due to multiple reflections. Experimental results agree with theory coherently and are compared with laser Doppler vibration meter showing a dynamical error better than 20 nm in ultrasonic vibration measurement.

  3. Design and Fabrication of 1.06 μm Resonant-Cavity Enhanced Reflective Modulator with GaInAs/GaAs Quantum Wells

    Institute of Scientific and Technical Information of China (English)

    YANG Xiao-Hong; HAN Qin; NI Hai-Qiao; HUANG She-Song; DU Yun; PENG Hong-Ling; XIONG Yong-Hua; NIU Zhi-Chuan; WU Rong-Han

    2006-01-01

    A resonant-cavity enhanced reflective optical modulator is designed and fabricated, with three groups of three highly strained InGaAs/GaAs quantum wells in the cavity, for low voltage and high contrast ratio operation.The quantum wells are positioned in antinodes of the optical standing wave. The modulator is grown in a single growth step in an molecular beam epitaxy system, using GaAs/AlAs distributed Bragg reflectors as both the top and bottom mirrors. Results show that the reflection device has a modulation extinction of 3 dB at -4.5 V bias.

  4. Hot-cavity studies for the Resonance Ionization Laser Ion Source

    Energy Technology Data Exchange (ETDEWEB)

    Henares, J.L., E-mail: henares@ganil.fr [GANIL, BP 55027, 14076 Caen Cedex 5 (France); Lecesne, N.; Hijazi, L.; Bastin, B. [GANIL, BP 55027, 14076 Caen Cedex 5 (France); Kron, T. [Johannes Gutenberg-Universität Mainz, Staudinger Weg 7, 55099 Mainz (Germany); Lassen, J. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, Canada V6T 2A3 (Canada); Le Blanc, F. [IPN Orsay, BP 1-91406 Orsay (France); Leroy, R.; Osmond, B. [GANIL, BP 55027, 14076 Caen Cedex 5 (France); Raeder, S. [Johannes Gutenberg-Universität Mainz, Staudinger Weg 7, 55099 Mainz (Germany); KU Leuven, Oude Markt 13, 3000 Leuven (Belgium); Schneider, F.; Wendt, K. [Johannes Gutenberg-Universität Mainz, Staudinger Weg 7, 55099 Mainz (Germany)

    2016-09-11

    The Resonance Ionization Laser Ion Source (RILIS) has emerged as an important technique in many Radioactive Ion Beam (RIB) facilities for its reliability, and ability to ionize target elements efficiently and element selectively. GISELE is an off-line RILIS test bench to study the implementation of an on-line laser ion source at the GANIL separator facility. The aim of this project is to determine the best technical solution which combines high selectivity and ionization efficiency with small ion beam emittance and stable long term operation. The ion source geometry was tested in several configurations in order to find a solution with optimal ionization efficiency and beam emittance. Furthermore, a low work function material was tested to reduce the contaminants and molecular sidebands generated inside the ion source. First results with ZrC ionizer tubes will be presented. Furthermore, a method to measure the energy distribution of the ion beam as a function of the time of flight will be discussed.

  5. Excitation of the ionospheric resonance cavity by neutral winds at middle latitudes

    Directory of Open Access Journals (Sweden)

    V. V. Surkov

    2004-09-01

    Full Text Available A new mechanism for the ionospheric Alfvén resonator (IAR excitation at middle latitudes is considered. It is shown that the ionosphere wind system in this region is capable of sustaining the generation of geomagnetic perturbations that can be detected by ground magnetometers. The general IAR dispersion relation describing the linear coupling of the shear Alfvén and fast magnetosonic/compressional modes is obtained. The dependence of the IAR eigenfrequencies and damping rates on the perpendicular wave number and on the ground conductivity during the day- and nighttime conditions is analyzed both analytically and numerically. In order to demonstrate the IAR excitation by neutral winds the power spectra of the geomagnetic perturbation on the ground surface are calculated. Furthermore, it is found that Kolmogorov spectra of the ionospheric turbulent neutral winds and the IAR eigenfrequencies lie in the same frequency range that make it possible to enhance the IAR excitation. The relevance of the developed theoretical model to the ground-based observations is stressed.

  6. Design and Performance of (Au,Yb)/ZnS/InSe/C Heterojunctions as Plasmon Resonators, Photodetectors and Microwave Cavities

    Science.gov (United States)

    Khusayfan, Najla M.; Khanfar, Hazem K.

    2016-12-01

    In this study, we concentrate on the design and characterization of the hybrid isotype (Au, Yb)/ZnS/InSe/C devices. The thin film devices that are prepared by using the vacuum deposition technique are characterized by means of x-ray diffraction, energy dispersive x-ray analysis, optical and dielectric spectroscopy, current-voltage characteristics and impedance spectroscopy techniques. The techniques allow determining the preferred crystallinity at the interfaces, the lattice match/mismatch ratios, the atomic compositions, the energy band gap shifts, the valence and conduction band offsets, the barrier heights at the Schottky shoulders (Au/ZnS and InSe/C) of the hybrid structure and the plasmonic interaction at the ZnS/InSe and (Au, Yb)/ZnS/InSe interfaces. The hybrid isotype device is found to exhibit photosensing features presented by a responsivity of ˜2.0 A/W, external quantum efficiencies (EQE) and internal quantum efficiencies (IQE) of 395% and 2493%, at basing voltage of 0.3 V, respectively. In addition, the dielectric spectra modeling reveals a plasmon-electron interaction of resonance frequencies in the range of 0.31-5.26 GHz and drift mobility of ˜212 cm2/Vs and 106 cm2/Vs for the Au/ZnS/InSe and Yb/ZnS/InSe, respectively. Moreover, the impedance spectroscopy studies confirm the correctness of the dielectric modeling nominating the Yb/ZnS/InSe/C devices as photodetectors, plasmon resonators and microwave cavities.

  7. Design and Performance of (Au,Yb)/ZnS/InSe/C Heterojunctions as Plasmon Resonators, Photodetectors and Microwave Cavities

    Science.gov (United States)

    Khusayfan, Najla M.; Khanfar, Hazem K.

    2017-03-01

    In this study, we concentrate on the design and characterization of the hybrid isotype (Au, Yb)/ZnS/InSe/C devices. The thin film devices that are prepared by using the vacuum deposition technique are characterized by means of x-ray diffraction, energy dispersive x-ray analysis, optical and dielectric spectroscopy, current-voltage characteristics and impedance spectroscopy techniques. The techniques allow determining the preferred crystallinity at the interfaces, the lattice match/mismatch ratios, the atomic compositions, the energy band gap shifts, the valence and conduction band offsets, the barrier heights at the Schottky shoulders (Au/ZnS and InSe/C) of the hybrid structure and the plasmonic interaction at the ZnS/InSe and (Au, Yb)/ZnS/InSe interfaces. The hybrid isotype device is found to exhibit photosensing features presented by a responsivity of ˜2.0 A/W, external quantum efficiencies (EQE) and internal quantum efficiencies (IQE) of 395% and 2493%, at basing voltage of 0.3 V, respectively. In addition, the dielectric spectra modeling reveals a plasmon-electron interaction of resonance frequencies in the range of 0.31-5.26 GHz and drift mobility of ˜212 cm2/Vs and 106 cm2/Vs for the Au/ZnS/InSe and Yb/ZnS/InSe, respectively. Moreover, the impedance spectroscopy studies confirm the correctness of the dielectric modeling nominating the Yb/ZnS/InSe/C devices as photodetectors, plasmon resonators and microwave cavities.

  8. Retrieving the spatial distribution of cavity modes in dielectric resonators by near-field imaging and electrodynamics simulations.

    Science.gov (United States)

    Goñi, Alejandro R; Güell, Frank; Pérez, Luis A; López-Vidrier, Julian; Ossó, J Oriol; Coronado, Eduardo A; Morante, Joan R

    2012-03-01

    For good performance of photonic devices whose working principle is based on the enhancement of electromagnetic fields obtained by confining light into dielectric resonators with dimensions in the nanometre length scale, a detailed knowledge of the optical mode structure becomes essential. However, this information is usually lacking and can only be indirectly obtained by conventional spectroscopic techniques. Here we unraveled the influence of wire size, incident wavelength, degree of polarization and the presence of a substrate on the optical near fields generated by cavity modes of individual hexagonal ZnO nanowires by combining scanning near-field optical microscopy (SNOM) with electrodynamics calculations within the discrete dipole approximation (DDA). The near-field patterns obtained with very high spatial resolution, better than 50 nm, exhibit striking size and spatial-dispersion effects, which are well accounted for within DDA, using a wavevector-dependent dipolar interaction and considering the dielectric anisotropy of ZnO. Our results show that both SNOM and DDA simulations are powerful tools for the design of optoelectronic devices able to manipulate light at the nanoscale.

  9. Coupled cavity QED for coherent control of photon transmission (II): Slowing light in coupled resonator waveguide doped with $\\Lambda $ Atoms

    CERN Document Server

    Zhou, L; Sun, C P; Lu, Jing; Zhou, Lan

    2006-01-01

    In the first paper of our series of articles on photon transmission in the coupled resonator optical waveguide (CROW), we used the two time Green function approach to study the physical mechanism for the coherent control by doping two-level atoms. In present paper, we propose and study a hybrid mechanism for photon transmission in the CROW by incorporating the electromagnetically induced transparency (EIT) effect in the doping artificial atoms and the band structure of the CROW. Here, the configuration setup of system, similar to that in the first paper, consists of a CROW with homogeneous couplings and the artificial atoms with $\\Lambda$-type three levels doped in each cavity. Unlike the stimulated Raman process used in the first paper to reduce the three level systems into the two level ones, the roles of three levels are completely considered based on a kind of mean field approach where the collection of three-level atoms collectively behave as two-mode spin waves. Then the total system is reduced into an ...

  10. Using active resonator impedance matching for shot-noise limited, cavity enhanced amplitude modulated laser absorption spectroscopy.

    Science.gov (United States)

    Chow, Jong H; Littler, Ian C M; Rabeling, David S; McClelland, David E; Gray, Malcolm B

    2008-05-26

    We introduce a closed-loop feedback technique to actively control the coupling condition of an optical cavity, by employing amplitude modulation of the interrogating laser. We show that active impedance matching of the cavity facilitates optimal shot-noise sensing performance in a cavity enhanced system, while its control error signal can be used for intra-cavity absorption or loss signal extraction. We present the first demonstration of this technique with a fiber ring cavity, and achieved shot-noise limited loss sensitivity. We also briefly discuss further use of impedance matching control as a tool for other applications.

  11. From ultraviolet to green InGaN-based conventional and resonant-cavity light-emitting diodes grown by molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Naranjo, F.B.; Fernandez, S.; Calle, F.; Sanchez-Garcia, M.A.; Calleja, E. [ISOM, ETSI Telecomunicacion, Universidad Politecnica de Madrid, Ciudad Universitaria, 28040 Madrid (Spain); Dpto. Ingenieria Electronica, ETSI Telecomunicacion, Universidad Polittecnica de Madrid (Spain)

    2002-08-16

    InGaN/GaN multiple quantum wells grown by molecular beam epitaxy were used as the active layer of standard and resonant-cavity light emitting diodes. Varying the In content in the wells from 1% to 35% and the well thickness from 1 to 2.5 nm, the room temperature electroluminescence can be tuned from 370 nm (ultraviolet) to 510 nm (green). The main factor that determines the emission energy in the well is the exciton localization for narrow wells, whereas for well thicknesses larger than 3 nm the piezoelectric field is the key factor, even for high In contents. Green resonant-cavity light emitting diodes have been successfully fabricated with a semitransparent AlGaN/GaN-based distributed bragg reflector as bottom mirror and an Al coating as top mirror. The external efficiency of those devices is increased by a factor of 10 compared to standard light emitting diodes. (Abstract Copyright[2002], Wiley Periodicals, Inc.)

  12. Methods of Measuring Lock-In Strength and their Application to the Case of Flow over a Cavity Locking into a Single Side Branch Resonator

    Energy Technology Data Exchange (ETDEWEB)

    Richard S. Mendelson

    2003-04-16

    Lock-in is a non-linear interaction between a flow induced noise source and a resonator when their respective frequencies are near each other. Lock-in has been reported under many different labels and for many different applications. There is a need however for a consistent community wide method to measure the strength of lock-in so that data from different tests and different source/resonator combinations can be compared. This paper discusses three methods for measuring lock-in strength. The first, Resonant Response Method, (RRM) subtracts (in the decibel scale) the linear modal response of the resonator to broadband (BB) flow noise from the resonant response when lock-in occurs. The second, Quality Factor Method (QFM) tracks the change in quality factor of the resonant response. The third defines the strength in terms of the difference between peak response and the local BB levels. The RRM is applied to a fundamental test in water of a weak source from grazing flow over a cavity locking into acoustic resonant modes of a single side branch resonator. The major velocity effects are captured in the resonant response to BB flow and not in lock-in strength. However, Strouhal stage number and modal damping is shown to have a significant impact on strength. For two modes, strength versus flow rate using the RRM is compared to strengths obtained using the QFM; on a decibel scale the results are shown to be within experimental uncertainty. However, the QFM is noticeably more difficult to apply. The author recommends the use of the Resonant Response Method as the most tractable measure of lock-in strength.

  13. Optical characterization and selective addressing of the resonant modes of a micropillar cavity with a white light beam

    NARCIS (Netherlands)

    Ctistis, Georgios; Hartsuiker, Alex; Pol, van der Edwin; Claudon, Julien; Vos, Willem L.; Gérard, Jean-Michel

    2010-01-01

    We have performed white light reflectivity measurements on GaAs/AlAs micropillar cavities with diameters ranging from 1 μm up to 20 μm. We are able to resolve the spatial field distribution of each cavity mode in real space by scanning a small-sized beam across the top facet of each micropillar. We

  14. The effect of cavity tuning on oxygen beam currents of an A-ECR type 14 GHz electron cyclotron resonance ion source.

    Science.gov (United States)

    Tarvainen, O; Orpana, J; Kronholm, R; Kalvas, T; Laulainen, J; Koivisto, H; Izotov, I; Skalyga, V; Toivanen, V

    2016-09-01

    The efficiency of the microwave-plasma coupling plays a significant role in the production of highly charged ion beams with electron cyclotron resonance ion sources (ECRISs). The coupling properties are affected by the mechanical design of the ion source plasma chamber and microwave launching system, as well as damping of the microwave electric field by the plasma. Several experiments attempting to optimize the microwave-plasma coupling characteristics by fine-tuning the frequency of the injected microwaves have been conducted with varying degrees of success. The inherent difficulty in interpretation of the frequency tuning results is that the effects of microwave coupling system and the cavity behavior of the plasma chamber cannot be separated. A preferable approach to study the effect of the cavity properties of the plasma chamber on extracted beam currents is to adjust the cavity dimensions. The results of such cavity tuning experiments conducted with the JYFL 14 GHz ECRIS are reported here. The cavity properties were adjusted by inserting a conducting tuner rod axially into the plasma chamber. The extracted beam currents of oxygen charge states O(3+)-O(7+) were recorded at various tuner positions and frequencies in the range of 14.00-14.15 GHz. It was observed that the tuner position affects the beam currents of high charge state ions up to several tens of percent. In particular, it was found that at some tuner position / frequency combinations the plasma exhibited "mode-hopping" between two operating regimes. The results improve the understanding of the role of plasma chamber cavity properties on ECRIS performances.

  15. The effect of cavity tuning on oxygen beam currents of an A-ECR type 14 GHz electron cyclotron resonance ion source

    Science.gov (United States)

    Tarvainen, O.; Orpana, J.; Kronholm, R.; Kalvas, T.; Laulainen, J.; Koivisto, H.; Izotov, I.; Skalyga, V.; Toivanen, V.

    2016-09-01

    The efficiency of the microwave-plasma coupling plays a significant role in the production of highly charged ion beams with electron cyclotron resonance ion sources (ECRISs). The coupling properties are affected by the mechanical design of the ion source plasma chamber and microwave launching system, as well as damping of the microwave electric field by the plasma. Several experiments attempting to optimize the microwave-plasma coupling characteristics by fine-tuning the frequency of the injected microwaves have been conducted with varying degrees of success. The inherent difficulty in interpretation of the frequency tuning results is that the effects of microwave coupling system and the cavity behavior of the plasma chamber cannot be separated. A preferable approach to study the effect of the cavity properties of the plasma chamber on extracted beam currents is to adjust the cavity dimensions. The results of such cavity tuning experiments conducted with the JYFL 14 GHz ECRIS are reported here. The cavity properties were adjusted by inserting a conducting tuner rod axially into the plasma chamber. The extracted beam currents of oxygen charge states O3+-O7+ were recorded at various tuner positions and frequencies in the range of 14.00-14.15 GHz. It was observed that the tuner position affects the beam currents of high charge state ions up to several tens of percent. In particular, it was found that at some tuner position / frequency combinations the plasma exhibited "mode-hopping" between two operating regimes. The results improve the understanding of the role of plasma chamber cavity properties on ECRIS performances.

  16. Malignant tumors of the nasal cavity: computed tomography and magnetic resonance imaging; Tumores malignos da cavidade nasal: tomografia computadorizada e ressonancia magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Ricardo Pires de; Paes Junior, Ademar Jose de Oliveira; Gonzalez, Fabio Mota; Cordeiro, Flamarion de Barros; Yamashiro, Ilka [Complexo Hospitalar Heliopolis, Sao Paulo, SP (Brazil). Programa de Residencia Medica em Radiologia e Diagnostico por Imagem]. E-mail: ricapires@ig.com.br; Lenh, Carlos Neutzling [Complexo Hospitalar Heliopolis, Sao Paulo, SP (Brazil). Servico de Cirurgia de Cabeca e Pescoco; Rapoport, Abrao [Complexo Hospitalar Heliopolis, Sao Paulo, SP (Brazil). Curso de Pos-graduacao em Ciencias da Saude

    2004-10-01

    The aim of this study is to evaluate the role of computed tomography and magnetic resonance imaging in the characterization of deep tissue extension of malignant tumors of the nasal cavity. Twelve patients diagnosed with malignant tumors of the nasal cavity were retrospectively evaluated at the Departments of Diagnostic Imaging and Head and Neck Surgery of the 'Complexo Hospitalar Heliopolis', Sao Paulo, Brazil, between 1990 and 2000. All cases were confirmed by histopathologic examination. The results were: extension to the maxillary and ethmoid sinuses was identified in six patients, extension to contralateral nasal cavity, orbit and lamina cribosa in five patients, extension to nasal pharynx and masticator space in two patients, extension to cavernous sinus, anterior/middle cranial fossa, pterygomaxillary fossa, inferior/superior orbital fissure, frontal sinus, contralateral ethmoid sinus, contralateral lamina cribosa, hard palate and pterygopalatine fossa in one patient. Conclusion: It is important to precisely assess the local extension and spread of tumor by computed tomography and magnetic resonance imaging in order to plan the approach to treatment, which will influence the prognosis. (author)

  17. Approximate Teleportation of an Unknown Atomic-Entangled State with Dissipative Atom-Cavity Resonant Jaynes-Cummings Model

    Institute of Scientific and Technical Information of China (English)

    LIU Zong-Liang; LI Shao-Hua; CHEN Chang-Yong

    2008-01-01

    We propose a scheme for approximately and conditionally teleporting an unknown atomic-entangled state in dissipative cavity QED.It is the further development of the scheme of [Phys.Rev.A 69 (2004) 064302],where the cavity mode decay has not been considered and the state teleportated is an unknown atomic state.In this paper,we investigate the influence of the decay on the approximate and conditional teleportation of the unknown atomic-entangled state,which is different from that teleportated in [Phys.Rev.A 69 (2004) 064302] and then give the fidelity of the teleportation,which depends on the cavity mode decay.The scheme may be generalized to not only the teleportation of the cavity-mode-entangled-state by means of a single atom but also the teleportation of the unknown trapped-ion-entangled-state in a linear ion trap.

  18. A Design of Constant Temperature Heating Circuit for a Resonant Cavity%一种谐振腔体的恒温加热电路设计

    Institute of Scientific and Technical Information of China (English)

    钦华

    2015-01-01

    For resonant cavity method is used to analyze cigarette density and humidity detection process,the stability of the resonant frequency accuracy of the test is very important.In this paper,a design scheme of con-stant temperature heating circuit for a resonant cavity in microwave density and humidity detector is presented, first introduces the measuring principle and architecture of the circuit,and then introduces the design and im-plementation,final y,experiments show that the design can meet the microwave detector testing requirements for measuring accuracy and stability.%对于利用谐振腔法对烟支进行湿密度检测过程中,谐振频率的稳定对测试精度至关重要。该文提出了一种微波密度湿度检测仪中谐振腔体恒温加热电路的设计方案,先介绍了该电路构成和原理,然后介绍了电路设计与实现,最后通过实验表明该电路可以满足微波密度湿度检测仪对测量精度和稳定性的要求。

  19. HF power couplers for pulsed superconducting cavity resonators; Coupleurs de puissance HF pour cavites supraconductrices en mode pulse

    Energy Technology Data Exchange (ETDEWEB)

    Jenhani, Hassen [Laboratoire de l' Accelerateur Lineaire, IN2P3-CNRS et Universite de Paris-Sud, BP 34, F-91898 Orsay Cedex (France)

    2006-11-15

    Recent years have seen an impressive improvement in the accelerating gradients obtained in superconducting cavities. Consequently, such cavities have become attractive candidates for large superconducting linear accelerator projects such as the European XFEL and the International Linear Collider (ILC). As a result, there is a strong interest in reducing RF conditioning time and improving the performance of the input power couplers for these cavities. The so-called TTF-III input power coupler, adopted for the XFEL superconducting RF cavities are complex components. In order to better understand the behavior of this component we have performed a series of experiments on a number of such couplers. Initially, we developed a fully automated RF high power test stand for coupler conditioning procedure. Following this, we performed a series of coupler conditioning tests. This has allowed the study of the coupler behavior during processing. A number of experiments were carried out to evaluate the in-situ baking effect on the conditioning time. Some of the conditioned couplers were sent to DESY in order to be tested on 9-cells TESLA cavities under cryogenic conditions. These tests have shown that the couplers in no way limit the cavity performance, even up to gradients of 35 MV/m. The main objective of our coupler studies was the reduction of their conditioning time, which represents one of the most important criteria in the choice of coupler for high energy linacs. Excellent progress in reducing the conditioning time has been demonstrated by making appropriate modifications to the conditioning procedure. Furthermore, special attention was paid to electron generation processes in the couplers, via multipacting. Simulations of this process were made on both the TTF-III coupler and on a new coupler prototype, TTF-V. Experiments aimed at suppressing multipacting were also successfully achieved by using a DC bias on the inner conductor of the co-axial coupler. (author)

  20. Maintenance of the resonance in a cavity filled with a variable density plasma; Entretien de la resonance d'une cavite chargee par un plasma de densite variable

    Energy Technology Data Exchange (ETDEWEB)

    Melin, G. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-07-01

    A study has been made of the possibility of keeping in resonance a cavity filled with a plasma of variable density; only the low HF power zone has been examined (less than a few dozen W). A calculation is first made, for the chosen experimental conditions, of the slipping of the resonance frequency of a cavity as a function of the plasma parameters (density, temperature), with a view to obtaining an idea of its importance. A description is then given of the experimental set-up: the S band cavity (3000 Mc/sec) is supplied by a carcinotron type generator; use is made of the plasma of a positive column whose density ({approx}10{sup 11} cm{sup -3}) can easily be controlled so as to obtain slipping of the cavity frequency ({delta}F{sub max} {approx} 50 Mc/s). The zone of automatic agreement thus obtained for the S band is 3 per cent continuously ({approx}100 Mc/s) and 1 per cent ({approx}30 Mc/s) with a response time of 10 {mu}s (sudden changes in density, {delta}n {approx} 5.10{sup 10} cm{sup 3}). These characteristics already compare very favorably with existing systems, and can easily be improved. (author) [French] On etudie une possibilite de maintenir a la resonance une cavite chargee par un plasma dont la densite varie; on se limite au domaine des puissances HF faibles (< quelques dizaines de W). On calcule tout d'abord, pour les conditions experimentales choisies, le glissement de la frequence de resonance d'une cavite en fonction des parametres du plasma, densite, temperature, pour en evaluer les ordres de grandeur. On decrit ensuite la realisation experimentale: la cavite bande S (3000 Mc/s) est alimentee par un generateur du type carcinotron; on utilise le plasma d'une colonne positive, dont on controle facilement la densite ({approx}10{sup 11} cm{sup -3}) pour faire glisser en frequence la cavite ({delta}F{sub max} {approx} 50 Mc/s). La zone d'accord automatique obtenue ainsi pour la bande S est de 3 pour cent en continu ({approx}100 Mc

  1. Cavity spin optodynamics

    CERN Document Server

    Brahms, N

    2010-01-01

    The dynamics of a large quantum spin coupled parametrically to an optical resonator is treated in analogy with the motion of a cantilever in cavity optomechanics. New spin optodynamic phenonmena are predicted, such as cavity-spin bistability, optodynamic spin-precession frequency shifts, coherent amplification and damping of spin, and the spin optodynamic squeezing of light.

  2. Spontaneous creation and persistence of ground-state coherence in a resonantly driven intra-cavity atomic ensemble

    CERN Document Server

    Norris, D G; Orozco, L A; Barberis-Blostein, P; Carmichael, H J; 10.1103/PhysRevA.86.053816

    2012-01-01

    The spontaneous creation and persistence of ground-state coherence in an ensemble of intracavity Rb atoms has been observed as a quantum beat. Our system realizes a quantum eraser, where the detection of a first photon prepares a superposition of ground-state Zeeman sublevels, while detection of a second erases the stored information. Beats appear in the time-delayed photon-photon coincidence rate (intensity correlation function). We study the beats theoretically and experimentally as a function of system parameters, and find them remarkably robust against perturbations such as spontaneous emission. Although beats arise most simply through single-atom-mediated quantum interference, scattering pathways involving pairs of atoms interfere also in our intracavity experiment. We present a detailed model which identifies all sources of interference and accounts for experimental realities such as imperfect pre-pumping of the atomic beam, cavity birefringence, and the transit of atoms across the cavity mode.

  3. Cavity-enhanced spectroscopies

    CERN Document Server

    van Zee, Roger

    2003-01-01

    ""Cavity-Enhanced Spectroscopy"" discusses the use of optical resonators and lasers to make sensitive spectroscopic measurements. This volume is written by the researcchers who pioneered these methods. The book reviews both the theory and practice behind these spectroscopic tools and discusses the scientific discoveries uncovered by these techniques. It begins with a chapter on the use of optical resonators for frequency stabilization of lasers, which is followed by in-depth chapters discussing cavity ring-down spectroscopy, frequency-modulated, cavity-enhanced spectroscopy, intracavity spectr

  4. RESONANCE CONTROL FOR THE COUPLED CAVITY LINAC AND DRIFT TUBE LINAC STRUCTURES OF THE SPALLATION NEUTRON SOURCE LINAC USING A CLOSED-LOOP WATER COOLING SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Bernardin, J. D. (John D.); Brown, R. L. (Richard L.); Brown, S. K. (Stanley K.); Bustos, G. R. (Gerald R.); Crow, M.L. (Martin L.); Gregory, W. S.; Hood, M. E. (Michael E.); Jurney, J. D. (James D.); Medalen, I. (Ivan); Owen, A. C. (Albert C.); Weiss, Robert E.

    2001-01-01

    The Spallation Neutron Source (SNS) is a facility being designed for scientific and industrial research and development. SNS will generate and use neutrons as a diagnostic tool for medical purposes, material science, etc. The neutrons will be produced by bombarding a heavy metal target with a high-energy beam of protons, generated and accelerated with a linear particle accelerator, or linac. The low energy end of the linac consists of two room temperature copper structures, the drift tube linac (DTL), and the coupled cavity linac (CCL). Both of these accelerating structures use large amounts of electrical energy to accelerate the protons to an energy of 185 MeV. Approximately 60-80% of the electrical energy is dissipated in the copper structure and must be removed. This is done using specifically designed water cooling passages within the linac's copper structure. Cooling water is supplied to these cooling passages by specially designed resonance control and water cooling systems.

  5. Investigating the electron density of multi-MeV X-ray-induced air plasmas at low pressures based on electromagnetic resonant cavity analysis

    Science.gov (United States)

    Ribière, M.; d'Almeida, T.; Cessenat, O.; Maulois, M.; Pouzalgues, R.; Crabos, B.; Delbos, C.; Garrigues, A.; Azaïs, B.

    2016-12-01

    We investigate air plasmas generated by multi-MeV pulsed X-rays at pressures ranging from 10-5 to 10-1 mbar. The experimental approach used for these studies is based on measurements of resonant frequencies damping and shift for different electromagnetic modes within a cylindrical cavity. Time-integrated electron densities in X-ray-induced air plasmas are inferred from the damping rate of the measured magnetic fields and their corresponding frequency shifts. In the present study, electron densities ranging from 108 to 109 cm-3 at pressures ranging from 10-3 to 10-1 mbar have been measured. Experimental results were confronted to 3D Maxwell-Vlasov Particle-In-Cell simulations incorporating a radiation-induced electric conductivity model. The method used in this work enables determining microscopic and macroscopic physical quantities within low pressure air plasmas generated by pulsed X-ray.

  6. Development of Control System for Fast Frequency Tuners of Superconducting Resonant Cavities for FLASH and XFEL Experiments

    CERN Document Server

    Przygoda, K

    2011-01-01

    This dissertation covers the recent research and development (R&D) activities of control systems for the fast frequency tuners of TESLA cavities and predicts the implications foreseen for large scale machines such as the FLASH and the planned XFEL. In particular, the framework of the presented activities is the effort toward the: 1. R&D of the driving circuit, 2. R&D of the control algorithm, 3. R&D of the control system. The main result of these activities is the permanent installation of the target piezo control system and its commissioning for 40 cavities divided into 5 accelerating modules at the DESY FLASH facility. The author’s contribution was the study of possible designs of high-voltage, high-current power amplifiers, used for driving the fast frequency tuners, shows that several parameters of such a device needs to be considered. The most important parameter is the input and output power estimation. This arises from the fact that the estimation is the most crucial issue for both po...

  7. Tumores malignos da cavidade nasal: tomografia computadorizada e ressonância magnética Malignant tumors of the nasal cavity: computed tomography and magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Ricardo Pires de Souza

    2004-10-01

    Full Text Available OBJETIVO: Este estudo propõe-se a avaliar o papel da tomografia computadorizada e da ressonância magnética na caracterização da extensão profunda dos tumores malignos da cavidade nasal. MATERIAIS E MÉTODOS: Entre 1990 e 2000 foram avaliados, retrospectivamente, 12 pacientes com diagnóstico de tumores malignos da cavidade nasal atendidos nos Departamentos de Diagnóstico por Imagem e Cirurgia de Cabeça e Pescoço do Complexo Hospitalar Heliópolis, São Paulo, SP. Todos os casos foram confirmados com exame anatomopatológico. RESULTADOS: Foi identificada extensão para os seios maxilares e etmoidal em seis pacientes, para a cavidade nasal contralateral, órbita e lâmina crivosa em cinco pacientes, para a nasofaringe e espaço mastigatório em dois pacientes, e para o seio cavernoso, fossas cranianas anterior e média, fossa pterigomaxilar, fissuras orbitárias superior e inferior, seio frontal, seio etmoidal contralateral, lâmina crivosa contralateral, palato duro e fossa pterigopalatina em um paciente. CONCLUSÃO: A análise precisa da extensão local e disseminação tumoral dada pela tomografia computadorizada e ressonância magnética desempenha papel importante no planejamento terapêutico, influenciando também o prognóstico.OBJECTIVE: The aim of this study is to evaluate the role of computed tomography and magnetic resonance imaging in the characterization of deep tissue extension of malignant tumors of the nasal cavity. MATERIALS AND METHODS: Twelve patients diagnosed with malignant tumors of the nasal cavity were retrospectively evaluated at the Departments of Diagnostic Imaging and Head and Neck Surgery of the "Complexo Hospitalar Heliópolis", São Paulo, Brazil, between 1990 and 2000. All cases were confirmed by histopathologic examination. RESULTS: Extension to the maxillary and ethmoid sinuses was identified in six patients, extension to contralateral nasal cavity, orbit and lamina cribosa in five patients, extension to

  8. Reduction in Depth for a Radiating Flange Backed by a Rectangular Resonant Cavity Using High Index Materials: Preliminary Report

    Science.gov (United States)

    2013-09-01

    All simulations have been run using the time domain solver of CST Studio Suite 2012, and adaptive meshing has been used to verify convergence in the...figures 6 and 7 in. a0 b a1 fc (MHz) d δ PW 30.68 13.64 9.7 192.5 4.1 0.27 0.7 7 3.1 Isotropic Materials When εr > 1 and μr > 1 this...μx = 10, μy = 1, and μz = 1. 13 Table 4. Cavity dimensions for figure 8 in inches. a0 b a1 fc (MHz) d δ PW L 26.25 11.7 8.3 225 4.2 0.29

  9. A resonance Raman enhancement mechanism for axial vibrational modes in the pyridine adduct of myoglobin proximal cavity mutant (H93G).

    Science.gov (United States)

    Franzen, Stefan; Brown, Derek; Gaff, John; Delley, B

    2012-09-06

    The proximal cavity mutant of myoglobin consists of a mutation of the proximal histidine to glycine (H93G), which permits exogenous ligands to bind to the heme iron. A non-native pyridine ligand can ligate to the heme to yield a five-coordinate adduct, H93G(Pyr), that cannot be formed freely in solution since the six-coordinate bis-pyridine adduct is more stable than the five-coordinate adduct. We have used resonance Raman spectroscopy in the Soret band region of the heme to study the enhancement of axial vibrations of bound pyridine in the H93G(Pyr) adduct. The observation that the pyridine ring breathing mode (ν(1)) and the symmetric ring stretching (ν(3)) modes are enhanced under these conditions is explained by a computational approach that shows that coupling of the π-system of the heme with the p-orbitals of the pyridine is analogous to π-backbonding in diatomic ligand adducts of heme proteins. The result has the broader significance that it suggests that the resonance enhancement of pyridine modes could be an important aspect of Raman scattering of pyridine on conducting surfaces such as those studied in surface enhanced Raman scattering experiments.

  10. Resonances

    DEFF Research Database (Denmark)

    an impetus or drive to that account: change, innovation, rupture, or discontinuity. Resonances: Historical Essays on Continuity and Change explores the historiographical question of the modes of interrelation between these motifs in historical narratives. The essays in the collection attempt to realize...... theoretical consciousness through historical narrative ‘in practice’, by discussing selected historical topics from Western cultural history, within the disciplines of history, literature, visual arts, musicology, archaeology, philosophy, and theology. The title Resonances indicates the overall perspective...

  11. Cavity magnomechanics

    Science.gov (United States)

    Zou, Chang-Ling; Zhang, Xufeng; Jiang, Liang; Tang, Hong

    2016-05-01

    Recently, cavity magnonics has attracted much attention for potential applications of coherent information transduction and hybrid quantum devices. The magnon is a collective spin wave excitation in ferromagnetic material. It is magnetically tunability, with long coherence time and non-reciprocical interaction with electro-magnetic fields. We report the coherent coupling between magnon, microwave photon and phonon. First, we demonstrate strong coupling and ultrastrong coupling between the magnon in YIG sphere and microwave photon in three-dimensional cavity. Then, based on the hybridized magnon-photon modes, we observe the triply resonant magnon-mcirowave photon-phonon coupling, where the ultrahigh-Q mechanical vibration of YIG sphere is dispersively coupled with the magnon via magnetostrictive interaction. We observe interesting phenomena, including electromagnetically induced transparency/absorption and parametric amplification. In particular, benefit from the large tunability of the magnon, we demonstrate a tunable microwave amplifier with gain as high as 30 dB. The single crystal YIG also has excellent optical properties, and thus provide a unique platform bridging MHz, GHz and THz information carriers. Finally, we present the latest progress towards coherent magnon to optical photon conversion.

  12. Regenerative feedback resonant circuit

    Science.gov (United States)

    Jones, A. Mark; Kelly, James F.; McCloy, John S.; McMakin, Douglas L.

    2014-09-02

    A regenerative feedback resonant circuit for measuring a transient response in a loop is disclosed. The circuit includes an amplifier for generating a signal in the loop. The circuit further includes a resonator having a resonant cavity and a material located within the cavity. The signal sent into the resonator produces a resonant frequency. A variation of the resonant frequency due to perturbations in electromagnetic properties of the material is measured.

  13. Improvement of the matching speed of AIMS for development of an automatic totally tuning system for hyperthermia treatment using a resonant cavity applicator.

    Science.gov (United States)

    Shindo, Y; Kato, K; Tsuchiya, K; Hirashima, T; Suzuki, M

    2009-01-01

    In this paper, we discuss the improvement of the speed of AIMS (Automatic Impedance Matching System) to automatically make impedance matching for a re-entrant resonant cavity applicator for non-invasive deep brain tumors hyperthermia treatments. We have already discussed the effectiveness of the heating method using the AIMS, with experiments of heating agar phantoms. However, the operating time of AIMS was about 30 minutes. To develop the ATT System (Automatic Totally Tuning System) including the automatic frequency tuning system, we must improve this problem. Because, when using the ATTS, the AIMS is used repeatedly to find the resonant frequency. In order to improve the speed of impedance matching, we developed the new automatic impedance matching system program (AIMS2). In AIMS, the stepping motors were connected to the impedance matching unit's dials. These dials were turned to reduce the reflected power. AIMS consists of two phases: all range searching and detailed searching. We focused on the three factors affecting the operating speed and improved them. The first factor is the interval put between the turning of the motors and AD converter. The second factor is how the steps of the motor when operating all range searching. The third factor is the starting position of the motor when detail searching. We developed the simple ATT System (ATT-beta) based on the AIMS2. To evaluate the developed AIMS2 and ATT- beta, experiments with an agar phantom were performed. From these results, we found that the operating time of the AIMS2 is about 4 minutes, which was approximately 12% of AIMS. From ATT-beta results, it was shown that it is possible to tune frequency and automatically match impedance with the program based on the AIMS2.

  14. 铁路混凝土箱梁箱内空腔共鸣噪声及其影响研究%Study on Cavity Resonance Noise of Railway Concrete Box-Girder and Its Influence

    Institute of Scientific and Technical Information of China (English)

    张迅; 王党雄; 李小珍

    2015-01-01

    为探讨铁路混凝土箱梁箱内空腔共鸣噪声及其影响,以某客运专线32 m预应力混凝土简支箱梁为研究对象,开展实桥振动与噪声试验,分析箱梁振动与噪声的时域特性及频谱特性。采用有限元法建立三维空腔声模型,分析箱内空腔声模态与腔内噪声峰值的关联性。采用边界元法分别建立两端封闭与两端开口的箱梁声学模型,验证箱内空腔共鸣噪声的来源及其影响。结果表明:在特定行车速度下,箱内噪声出现“拍”现象,显著增大箱内噪声,瞬时最大声压可达40 Pa,峰值频率为75.0 Hz;箱内噪声的“拍”现象来源于顶板的振动噪声,顶板的振动峰值频率与箱内空腔垂向声模态频率吻合时,箱内噪声显著增大;由于梁缝的声泄漏特性,箱内空腔共鸣噪声在梁缝处衰减较大,但其对桥梁两侧总体噪声的影响不可忽略。%In order to study the cavity resonance noise of concrete box-girder and its influence,a field test con-cerning vibration and noise of a 32 m PC simply-supported box-girder was carried out,to investigate the time-domain characteristics and frequency spectrum characteristics of vibration and noise of the box-girder.A 3D cavity acoustical model was established based on FEM to analyze the correlation between cavity acoustic mode and cavity noise peak.Two acoustical models for box-girders with closed ends and open ends,were built based on BEM,respectively,to verify the source and influence of cavity resonance noise.Results showed that the“beat”wave phenomenon of cavity noise appeared under a specific train speed,significantly increasing the cavi-ty noise,with the transient maximum sound pressure of cavity noise reaching 40 Pa and the noise peak frequen-cy being 75.0 Hz;The “beat”wave phenomenon of cavity noise derived from the vibration of deck.When the peak vibration frequency of deck matched with the frequency of vertical acoustic modal of the cavity

  15. Entanglement swapping between atom and cavity and generation of entangled state of cavity fields

    Institute of Scientific and Technical Information of China (English)

    Chen Ai-Xi; Deng Li

    2007-01-01

    This paper proposes a scheme where entanglement swapping between atom and cavity can be realized. A-type three-level atoms interacting resonantly with cavity field are considered. By detecting atom and cavity field, it realizes entanglement swapping between atom and cavity. It uses the technique of entanglement swapping to generate an entangled state of two cavity fields by measuring on atoms. It discusses the experimental feasibility of the proposed scheme and application of entangled state of cavity fields.

  16. Dielectric properties of oil sands at 2.45 GHz with TE1,0,11 mode determined by a rectangular cavity resonator.

    Science.gov (United States)

    Erdogan, Levent; Akyel, Cevdet; Ghannouchi, Fadhel M

    2011-01-01

    Oil obtained from oil sands resources constitute an important portion of the oil industry in Canada. Extraction of the bitumen from oil sands is very crucial process because of its cost and environmental impact. Microwave energy applicators by heating oil sands at microwave frequencies can be an excellent alternative to extract bitumen with the advantages of being potentially cost-effective and environmentally friendly method of extraction. In order to design and manufacture a microwave energy applicator, its dielectric properties must be known. In this study, as the first part of our ultimate microwave energy applicator project, in advance, the complex permittivity of oil sands was measured by using rectangular cavity resonator, designed and fabricated in Ecole Polytechnique de Montréal laboratories, at 2.45 GHz with TE1,0,1 mode. The accuracy of the permittivity measurement results obtained with the developed system was verified against those obtained using a commercial open-ended probe system as well the values of well known materials documented in open literature. Since there is no study found in the literature about the complex permittivity values of oil sands at 2.45 GHz, the present study would be of great help and important guide for those who plan to design and manufacture microwave energy applicators in order to extract the bitumen from the oil sands.

  17. Ultraintense short-wavelength emission from ZnO-sheathed MgO nanorods induced by subwavelength optical resonance cavity formation: verification of previous hypothesis.

    Science.gov (United States)

    Jin, Changhyun; Kim, Hyunsu; Lee, Chongmu

    2012-03-01

    A recent paper reported that intense emissions with a range of wavelengths over a wide spectral range, from ultraviolet to infrared light, might be possible by sheathing MgO nanorods with a semiconducting material with an optimal sheath thickness. In addition, the paper hypothesized that an ultraintense short-wavelength emission could be obtained by sheathing MgO nanorods with a ~17 nm ZnO thin film in the paper. In this study, we found that the intensity ratio of the near-band edge emission to the deep level emission (I(NBE)/I(DL)) of the MgO-core/ZnO-shell nanorods with a mean shell layer thickness of 17 nm was as high as ~30, whereas the I(NBE)/I(DL) ratio of the bare-MgO nanorods was 0. This near-band edge emission intensity enhancement by sheathing the MgO nanorods with ZnO is by far more significant than that by sheathing the ZnO nanorods with other materials including MgO. This is because subwavelength optical resonance cavities form in the MgO-core/ZnO-shell nanorods with faceted surfaces, whereas they do not form in the ZnO-core/MgO (or other material)-shell nanorods with no faceted surfaces.

  18. GaInNAs/GaAs Multiple-Quantum Well Resonant-Cavity-Enhanced Photodetectors at 1.3μm

    Institute of Scientific and Technical Information of China (English)

    潘钟; 李联合; 徐应强; 张伟; 林耀望; 张瑞康; 钟源; 任晓敏

    2001-01-01

    A GaInNAs/GaAs multiple quantum well (MQW) resonant-cavity enhanced photodetector (RCE-PD) operated at a wavelength of 1.3μm with the full width at half maximum of 4nm has been demonstrated. The GaInNAs RCE-PD was grown by molecular beam epitaxy using a homemade ion-removed dc plasma cell as a nitrogen source. GaInNAs/GaAs MQW shows a strong exciton peak at room temperature, which is very beneficial for applications in long-wavelength absorption devices. For a 100μm diameter RCE-PD, the dark current is 20 and 32 pA at biases of 0 and 6 V, respectively, and the breakdown voltage is -18 V. The measured 3 dB bandwidth is 308 MHz, which is limited by the resistance of p-type distributed Bragg reflector mirror. The tunable wavelength in a range of 18nm with the angle of incident light was observed.

  19. Experimental research on cavity resonance based on sound card and MMUSE software%基于声卡和MMUSE软件的空腔共振实验研究

    Institute of Scientific and Technical Information of China (English)

    吴肖; 熊建文

    2016-01-01

    This paper introduces the application of a free and open-source software called MMUSE in researching cavity resonance based on the computer sound card.This experimental method can measure the resonant frequency accurately and test the resonance frequency formula according to the theory of Helmholtz resonance.%介绍了以科学教育多媒体软件 MMUSE(multimedia utilities for science education)为平台,基于声卡为采集系统进行的空腔共振实验研究,精确地测量了烧杯等空腔的共振频率,对赫姆霍兹共振子理论下的空腔共振频率公式进行了验证。

  20. Spectral investigation of hot-spot and cavity resonance effects on the terahertz radiation emitted from high-Tc superconducting Bi2Sr2CaCu2O8+δ single crystal mesa structures

    Science.gov (United States)

    Kadowaki, Kazuo; Watanabe, Chiharu; Minami, Hidetoshi; Yamamoto, Takashi; Kashiwagi, Takanari; Klemm, Richard

    2014-03-01

    Terahertz (THz) electromagnetic radiation emitted from high-Tc superconducting Bi2Sr2CaCu2O8+δ mesa structures in the case of single mesa and series-connected mesas is investigated by the FTIR spectroscopic technique while observing its temperature distribution simultaneously by a SiC photoluminescence technique. Changing the bias level, sudden jumps of the hot-spot position were clearly observed. Although the radiation intensity changes drastically associated with the jump of the hot spot position, the frequency is unaffected as long as the voltage per junction is kept constant. Since the frequency of the intense radiation satisfies the cavity resonance condition, we confirmed that the cavity resonance is of primarily importance for the synchronization of whole intrinsic Josephson junctions in the mesa for high power radiation. This work was supported in part by the Grant-in-Aid for challenging Exploratory Research, the Ministry of Education, Culture, Sports, Science & Technology (MEXT).

  1. Single and Coupled Nanobeam Cavities

    DEFF Research Database (Denmark)

    Ivinskaya, Aliaksandra; Lavrinenko, Andrei; Shyroki, Dzmitry M.

    2013-01-01

    for analysis and design of photonic crystal devices, such as 2D ring resonators for filters, single and coupled nanobeam cavities, birefringence in photonic crystal cavities, threshold analysis in photonic crystal lasers, gap solitons in photonic crystals, novel photonic atolls, dynamic characteristics...

  2. PREPARATION OF MANY-ATOM ENTANGLED STATE VIA THE QUANTIZED CAVITY FIELD RESONANT INTERACTION WITH ATOM%利用原子-腔场共振相互作用制备多原子缠结态(英)

    Institute of Scientific and Technical Information of China (English)

    陈昌永

    2002-01-01

    A scheme for preparation of the many-atom entangled state via the resonant interaction of quantized cavity with atom is presented.It is injected an two-level atom initially prepared in the superposition of the ground state and excited state through the cavity prepared in the vacuum state.The atom passing through the cavity creates atom-field entanglement.The other two-level atoms prepared in the ground states are injected into the cavity at different angles,respectively.After the interaction with the cavity field,the many-atom entangled state is produced and the cavity field is still in the vacuum state.Comparing with the existing schemes,ours is easier to realize experimently.%提出了一个利用量子腔场与原子的共振相互作用制备多原子缠结态的方案.首先将一个初态制备在基态和激发态的叠加态的二能级原子注入一个真空态腔场中.原子通过腔时产生原子-场缠结.制备于基态的其它二能级原子分别以不同角度注入腔场,在与腔场相互作用时可制得多原子缠结态,而空腔仍然保持在真空态.与现存的方案比较,该方案在实验上更容易实现.

  3. 采用谐振腔微扰法的NiZn铁氧体介电常数测量%Measurement of complex permittivity of NiZn-ferrite by resonant cavity perturbation method

    Institute of Scientific and Technical Information of China (English)

    王翠平; 叶柳; 李爱侠; 张子云; 刘晨; 张利飞

    2012-01-01

    The cavity perturbation technique has been widely used for microwave dielectric properties measurements. It has the great advantages of convenient experimental measurement, small sample dimension, and simple computation formulas. It has a good application value in approximate calculation frequency and the quality factor of resonant cavity, material dielectric constant. The complex permittivity within microwave frequency band of NiZn ferrite was measured by resonator cavity perturbation method. The imaginary part e" and the real part e' of the dielectric constant were obtained, and the effects of content of Ni and Zn on complex permittivity were analyzed.%谐振腔微扰法广泛用于材料微波介电性能的测量,它与常规的测量方法相比,具有样品尺寸小、计算公式简单的优点,在近似计算频率、谐振腔品质因数、材料的介电常数等方面具有较高的应用价值.采用谐振腔微扰法,测量不同配方NiZn铁氧体在微波频段的复介电常数,计算得到介电常数的虚部ε″和实部ε′,进而分析Ni和Zn的含量对NiZn铁氧体材料介电常数的影响.

  4. L-Band Relative Permittivity of Organic Soil Surface Layers—A New Dataset of Resonant Cavity Measurements and Model Evaluation

    Directory of Open Access Journals (Sweden)

    Simone Bircher

    2016-12-01

    Full Text Available Global surface soil moisture products are derived from passive L-band microwave satellite observations. The applied retrieval algorithms include dielectric models (relating soil water content to relative permittivity developed for mineral soils. First efforts to generate equivalent models for areas where organic surface layers are present such as in the high-latitude regions have recently been undertaken. The objective of this study was to improve our still insufficient understanding of L-band emission of organic substrates in prospect of enhancing soil moisture estimations in the high latitudes undergoing most rapid climatic changes. To this end, L-band relative permittivity measurements using a resonant cavity were carried out on a wide range of organic surface layer types collected at different sites. This dataset was used to evaluate two already existing models for organic substrates. Some samples from underlying mineral layers were considered for comparison. In agreement with theory the bulk relative permittivity measured in organic substrate was decreased due to an increased bound water fraction (where water molecules are rotationally hindered compared to the measured mineral material and corresponding output of the dielectric model for mineral soils used in satellite algorithms. No distinct differences in dielectric response were detected in the measurements from various organic layer types, suggesting a generally uniform L-band emission behavior. This made it possible to fit a simple empirical model to the data obtained from all collected organic samples. Outputs of the two existing models both based on only one organic surface layer type were found to lie within the spread of our measured data, and in close proximity to the derived simple model. This general consensus strengthened confidence in the validity of all these models. The simple model should be suitable for satellite soil moisture retrieval applications as it is calibrated on

  5. Ray splitting in paraxial optical cavities

    CERN Document Server

    Puentes, G; Woerdman, J P

    2003-01-01

    We present a numerical investigation of the ray dynamics in a paraxial optical cavity when a ray splitting mechanism is present. The cavity is a conventional two-mirror stable resonator and the ray splitting is achieved by inserting an optical beam splitter perpendicular to the cavity axis. We show that depending on the position of the beam splitter the optical resonator can become unstable and the ray dynamics displays a positive Lyapunov exponent.

  6. Continuously tunable, split-cavity gyrotrons

    Science.gov (United States)

    Brand, G. F.; Gross, M.

    1985-12-01

    Attention is given to a gyrotron cavity configuration which is split in halves longitudinally, to allow any frequency lying between the fixed cavity resonance to be assessed by mechanically changing the separation of the two halves. Experimental results are presented which demonstrate that the rate-of-change in resonant frequency with separation is greatest if the minor axis of the cavity cross section is the one undergoing change. Excellent agreement with theory is noted for these results.

  7. A micropillar for cavity optomechanics

    CERN Document Server

    Kuhn, A G; Ducloux, O; Chartier, C; Traon, O Le; Briant, T; Cohadon, P -F; Heidmann, A; Michel, C; Pinard, L; Flaminio, R

    2011-01-01

    We present a new micromechanical resonator designed for cavity optomechanics. We have used a micropillar geometry to obtain a high-frequency mechanical resonance with a low effective mass and a very high quality factor. We have coated a 60-$\\mu$m diameter low-loss dielectric mirror on top of the pillar and are planning to use this micromirror as part of a high-finesse Fabry-Perot cavity, to laser cool the resonator down to its quantum ground state and to monitor its quantum position fluctuations by quantum-limited optical interferometry.

  8. Subwavelength rectangular cavity partially filled with left-handed materials

    Institute of Scientific and Technical Information of China (English)

    Jiang Tian; Chen Yan; Feng Yi-Jun

    2006-01-01

    In this paper, we present the electromagnetic analysis of a rectangular cavity partially filled with a left-handed material slab. Our theoretical investigation shows that there exist novel resonant modes in the cavity, and such a cavity becomes a subwavelength cavity. The eigenvalue equation of the cavity is derived and the resonant frequencies of the novel modes are calculated by using numerical simulation. We also discuss the stability of the novel resonant modes and show the best condition under which a useful rectangular cavity of subwavelength dimensions with tolerable stability is obtained.

  9. Controlled coupling of photonic crystal cavities using photochromic tuning

    CERN Document Server

    Cai, Tao; Solomon, Glenn S; Waks, Edo

    2013-01-01

    We present a method to control the resonant coupling interaction in a coupled-cavity photonic crystal molecule by using a local and reversible photochromic tuning technique. We demonstrate the ability to tune both a two-cavity and a three-cavity photonic crystal molecule through the resonance condition by selectively tuning the individual cavities. Using this technique, we can quantitatively determine important parameters of the coupled-cavity system such as the photon tunneling rate. This method can be scaled to photonic crystal molecules with larger numbers of cavities, which provides a versatile method for studying strong interactions in coupled resonator arrays.

  10. Folded waveguide resonator

    DEFF Research Database (Denmark)

    2013-01-01

    A waveguide resonator comprising a number of side walls defining a cavity enclosed by said sidewalls defining the cavity; and two or more conductive plates extending into the cavity, each conductive plate having a first side and a second side opposite the first side, and wherein the conductive...

  11. Teleportation of atomic states with a weak coherent cavity field

    Institute of Scientific and Technical Information of China (English)

    Zheng Shi-Biao

    2005-01-01

    A scheme is proposed for the teleportation of an unknown atomic state. The scheme is based on the resonant interaction of atoms with a coherent cavity field. The mean photon-number of the cavity field is much smaller than one and thus the cavity decay can be effectively suppressed. Another adwntage of the scheme is that only one cavity is required.

  12. 基于SOI衬底的谐振腔结构对锗直接带发光增强的研究%A Study on the Enhancement of Ge Direct Bandgap Photoluminescence Based on SOI Resonant Cavity

    Institute of Scientific and Technical Information of China (English)

    陈城钊

    2012-01-01

    SOI-based resonant cavity was theoretically designed basing on the transition matrix method. High-quality Ge and Ge/SiGe multiple quantum wells were grown on SOI-based germanium virtual substrates by ultrahigh vacuum chemical vapor deposition. The room temperature photoluminescence of the samples indi- cates that the SOI-based resonant cavity can effectively enhance the photoluminescence originated from the Ge direct bandgap, which is in good agreement with the theoretical prediction.%基于散射矩阵法对SOI衬底的谐振腔结构进行了理论设计.采用超高真空化学气相沉积系统,在SOI基的Ge虚衬底上制备出高质量的Ge和Ge/SiGe多量子阱材料.室温下样品的光致发光谱表明SOI衬底的谐振腔结构对锗直接带发光起有效的强度增强作用,实验结果与理论预期符合得很好.

  13. Nanofriction in Cavity Quantum Electrodynamics.

    Science.gov (United States)

    Fogarty, T; Cormick, C; Landa, H; Stojanović, Vladimir M; Demler, E; Morigi, Giovanna

    2015-12-01

    The dynamics of cold trapped ions in a high-finesse resonator results from the interplay between the long-range Coulomb repulsion and the cavity-induced interactions. The latter are due to multiple scatterings of laser photons inside the cavity and become relevant when the laser pump is sufficiently strong to overcome photon decay. We study the stationary states of ions coupled with a mode of a standing-wave cavity as a function of the cavity and laser parameters, when the typical length scales of the two self-organizing processes, Coulomb crystallization and photon-mediated interactions, are incommensurate. The dynamics are frustrated and in specific limiting cases can be cast in terms of the Frenkel-Kontorova model, which reproduces features of friction in one dimension. We numerically recover the sliding and pinned phases. For strong cavity nonlinearities, they are in general separated by bistable regions where superlubric and stick-slip dynamics coexist. The cavity, moreover, acts as a thermal reservoir and can cool the chain vibrations to temperatures controlled by the cavity parameters and by the ions' phase. These features are imprinted in the radiation emitted by the cavity, which is readily measurable in state-of-the-art setups of cavity quantum electrodynamics.

  14. RRR Characteristics for SRF Cavities

    CERN Document Server

    Jung, Yoochul; Joung, Mijoung

    2015-01-01

    The first heavy ion accelerator is being constructed by the rare isotope science project (RISP) launched by the Institute of Basic Science (IBS) in South Korea. Four different types of superconducting cavities were designed, and prototypes were fabricated such as a quarter wave resonator (QWR), a half wave resonator (HWR) and a single spoke resonator (SSR). One of the critical factors determining performances of the superconducting cavities is a residual resistance ratio (RRR). The RRR values essentially represent how much niobium is pure and how fast niobium can transmit heat as well. In general, the RRR degrades during electron beam welding due to the impurity incorporation. Thus it is important to maintain RRR above a certain value at which a niobium cavity shows target performance. In this study, RRR degradation related with electron beam welding conditions, for example, welding power, welding speed, and vacuum level will be discussed.

  15. radiofrequency cavity

    CERN Multimedia

    1988-01-01

    The pulse of a particle accelerator. 128 of these radio frequency cavities were positioned around CERN's 27-kilometre LEP ring to accelerate electrons and positrons. The acceleration was produced by microwave electric oscillations at 352 MHz. The electrons and positrons were grouped into bunches, like beads on a string, and the copper sphere at the top stored the microwave energy between the passage of individual bunches. This made for valuable energy savings as it reduced the heat generated in the cavity.

  16. Cavity spatial mode-locking and high controllability of radial output coupling for circular/square plasmonic nano-resonator lasers.

    Science.gov (United States)

    Chen, Xi; Huang, Yingyan; Ho, Seng-Tiong

    2015-02-01

    We proposed and investigated a novel output coupling scheme for a circular and a square plasmonic nano-ring laser based on a T-shaped radial coupler that is easier to realize than a tangential coupler. The amount of coupling efficiency is shown to be highly controllable from a few percent to tens of percents. This is due to the fact that the standing-wave lasing mode pattern will rotate to give the minimal cavity loss at the T-coupler's location, making the amount of output coupling surprisingly low and hence, controllable. For a non-circular cavity, other symmetry-breaking and geometry-induced scattering could result in separate mode-pattern locking. These give a few main ways to control and optimize the coupling efficiency: via widening/narrowing or rotating the T-coupler's waveguide, or, for the case of a non-circular cavity, via shifting the location of the T-coupler. We observed increased unidirectional lasing induced by either rotating the waveguide or shifting it (for non-circular cases). We simulated the coupling using Maxwell's equations based on the multi-level multi-electron FDTD (MLME-FDTD) method to realistically model the lasing and output coupling behaviors of such plasmonic semiconductor lasers.

  17. Entanglement distillation for atomic states via cavity QED

    Science.gov (United States)

    Yang, Ming; Song, Wei; Cao, Zhuo-Liang

    2004-10-01

    Following a recent proposal (Phys. Rev. Lett. 85 (2000) 2392) about quantum information processing using dispersive atom-cavity interaction, in this paper, we proposed a physical scheme to concentrate the pure non-maximally entangled atomic states via cavity QED by using atomic collision in a far-off-resonant cavity. The most distinctive advantage of our scheme is that there is no excitation of cavity mode during the distillation procedure. Therefore the requirement on the quality of cavity is greatly loosened.

  18. accelerating cavity

    CERN Multimedia

    On the inside of the cavitytThere is a layer of niobium. Operating at 4.2 degrees above absolute zero, the niobium is superconducting and carries an accelerating field of 6 million volts per metre with negligible losses. Each cavity has a surface of 6 m2. The niobium layer is only 1.2 microns thick, ten times thinner than a hair. Such a large area had never been coated to such a high accuracy. A speck of dust could ruin the performance of the whole cavity so the work had to be done in an extremely clean environment.

  19. Note: theoretical study on the gas pressure dependence of x-ray yield in TE(111) cavity based electron cyclotron resonance x-ray source.

    Science.gov (United States)

    Selvakumaran, T S; Sen, Soubhadra; Baskaran, R

    2014-11-01

    Adopting Langevin methodology, a pressure dependent frictional force term which represents the collisional effect is added to the Lorentz equation. The electrons are assumed to be starting from the uniformly distributed co-ordinates on the central plane. The trajectory of each electron is numerically simulated by solving the modified Lorentz equation for a given pressure. The Bremsstrahlung x-ray energy spectrum for each electron crossing the cavity wall boundary is obtained using the Duane-Hunt law. The total x-ray yield is estimated by adding the spectral contribution of each electron. The calculated yields are compared with the experimental results and a good agreement is found.

  20. Cavity-enhanced absorption for optical refrigeration

    CERN Document Server

    Seletskiy, Denis V; Sheik-Bahae, Mansoor

    2009-01-01

    A 20-fold increase over the single path optical absorption is demonstrated with a low loss medium placed in a resonant cavity. This has been applied to laser cooling of Yb:ZBLAN glass resulting in 90% absorption of the incident pump light. A coupled-cavity scheme to achieve active optical impedance matching is analyzed.

  1. Methods for precisely controlling the residual stress and temperature coefficient of the frequency of a MEMS resonator based on an AlN cavity silicon-on-insulator platform

    Science.gov (United States)

    Wang, Nan; Xu, Jinghui; Zhang, Xiaolin; Wu, Guoqiang; Zhu, Yao; Li, Wei; Gu, Yuandong

    2016-07-01

    In this paper, we report an experimentally verified numerical model developed for precisely predicting and controlling the initial bending of a multi-layer-stack composite cantilever structure which is caused by the residual stress of the individual constituting layers, as well as the cantilever’s thermal coefficient of frequency (TCF). The developed model is exemplified using a flexural-mode cantilever resonator according to the process flow of the aluminium nitride (AlN) cavity silicon-on-insulator (SOI) platform. The same AlN cavity SOI platform is also utilized to fabricate the exemplified cantilever, which is then used to experimentally verify the accuracy and consistency of the numerical model. The experimental results show a difference of less than 3.5% is observed in terms of the deflection at the tip of the cantilever as compared with the numerical model, demonstrating the accuracy of the developed numerical model and the feasibility to optimize the cantilever’s initial deflection and TCF simultaneously, achieving minimum values for both parameters at the same time.

  2. CHECHIA cavity driving with FPGA controller

    Energy Technology Data Exchange (ETDEWEB)

    Czarski, T.; Koprek, W.; Pozniak, K.T.; Romaniuk, R.S. [Technical Univ. Warsaw (Poland). ELHEP Laboratory, ISE; Simrock, S. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). TESLA

    2005-07-01

    The initial control of the superconductive cavity has recently been performed by applying the FPGA (Field Programmable Gate Array) technology system in DESY Hamburg. This first experiment turned attention to the general recognition of the cavity features and projected control methods. The electrical model of the cavity is taken as a consideration origin. The calibration of the signal channel is considered as a key preparation for an efficient cavity driving. The cavity parameters identification is confirmed as a proper approach for the required performance: driving on resonance during filling and field stabilization during flattop time with reasonable power consumption. The feed-forward and feedback modes were applied successfully for the CHECHIA cavity driving. Representative results of experiments are presented for different levels of the cavity field gradient. (orig.)

  3. Cavity Optomechanical Magnetometer

    CERN Document Server

    Forstner, S; Knittel, J; van Ooijen, E D; Swaim, J D; Harris, G I; Szorkovszky, A; Bowen, W P; Rubinsztein-Dunlop, H

    2011-01-01

    A cavity optomechanical magnetometer is demonstrated where the magnetic field induced expansion of a magnetostrictive material is transduced onto the physical structure of a highly compliant optical microresonator. The resulting motion is read out optically with ultra-high sensitivity. Detecting the magnetostrictive deformation of Terfenol-D with a toroidal whispering gallery mode (TWGM) resonator a peak sensitivity of 400 nT/Hz^.5 was achieved with theoretical modelling predicting that sensitivities of up to 500 fT/Hz^.5 may be possible. This chip-based magnetometer combines high-sensitivity and large dynamic range with small size and room temperature operation.

  4. Cavity optomechanical magnetometer.

    Science.gov (United States)

    Forstner, S; Prams, S; Knittel, J; van Ooijen, E D; Swaim, J D; Harris, G I; Szorkovszky, A; Bowen, W P; Rubinsztein-Dunlop, H

    2012-03-23

    A cavity optomechanical magnetometer is demonstrated. The magnetic-field-induced expansion of a magnetostrictive material is resonantly transduced onto the physical structure of a highly compliant optical microresonator and read out optically with ultrahigh sensitivity. A peak magnetic field sensitivity of 400  nT  Hz(-1/2) is achieved, with theoretical modeling predicting the possibility of sensitivities below 1  pT  Hz(-1/2). This chip-based magnetometer combines high sensitivity and large dynamic range with small size and room temperature operation.

  5. Interaction between dual cavity modes in a planar photonic microcavity

    Science.gov (United States)

    Noble, Elizabeth; Nair, Rajesh V.; Jagatap, B. N.

    2016-10-01

    We theoretically study the interaction between dual cavity modes in a planar photonic microcavity structure in the optical communication wavelength range. The merging and splitting of cavity mode is analysed with realistic microcavity structures. The merging of dual cavity resonance into a single cavity resonance is achieved by changing the number of layers between the two cavities. The splitting of single cavity resonance into dual cavity resonance is obtained with an increase in the reflectivity of mirrors in the front and rear side of the microcavity structure. The threshold condition for the merging and splitting of cavity mode is established in terms of structural parameters. The physical origin of the merging of dual cavity modes into a single cavity resonance is discussed in terms of the electric field intensity distribution in the microcavity structure. The microcavity structure with dual cavity modes is useful for the generation of entangled photon pairs, for achieving the strong-coupling regime between exciton and photon and for high-resolution multi-wavelength filters in optical communication.

  6. Simulation study on resonant cavity perturbation method to detectmoisture content of crude oil%谐振腔微扰法测量原油含水率仿真研究

    Institute of Scientific and Technical Information of China (English)

    郭文阁; 马文涛; 雍振; 张旋

    2016-01-01

    In comparison with the traditional on⁃line detecting method of moisture content of crude oil,the high⁃frequency microwave resonant cavity perturbation method is seldom influenced by the external environment and never influenced by the mineralization,and has high detecting accuracy. Since the permittivity of water and crude oil is significantly different,and the small change of water content can change the permittivity greatly,the crude oil with different moisture contents may result in the different losses of microwave field. The change of resonant frequency and quality factor of the microwave resonant cavity contain⁃ing perturbation source (sample crude oil) are detected by means of software simulation. The permittivity of sample crude oil can be obtained according the perturbation formula of rectangle resonant cavity. And then the obtained result is substituted into the relation formula reflecting crude oil moisture content and permittivity to get the permittivity of the sample moisture content of crude oil. The crude oil permittivity data detected in aluminum and copper boundary conditions is analyzed with the theoretical value,and the relative percentage error is found out. A simple,practical,fast and accurate method to detect the crude oil with medium and low moisture content is obtained.%与传统在线测量原油含水率的方法相比,高频微波谐振腔微扰法具有受外界环境影响小,不受矿化度影响,测量精度高的特点。由于原油和水的介电常数相差较大,微小的含水率变化会引起介电常数较大变化,使得不同含水率原油对微波场的损耗不同。通过软件仿真的方法可以测量出含微扰源(样品原油)的微波谐振腔的谐振频率和品质因数变化情况,根据矩形谐振腔微扰公式可得出样品原油的介电常数,然后将所得结果代入原油含水率和介电常数关系公式求得原油含水率。并且将铝制边界条件和铜制边界

  7. Mechanical Properties of Ingot Nb Cavities

    Energy Technology Data Exchange (ETDEWEB)

    Ciovati, Gianluigi; Dhakal, Pashupati; Kneisel, Peter; Mammosser, John; Matalevich, Joseph; Rao Myneni, Ganapati

    2014-07-01

    This contribution presents the results of measurements of the resonant frequency and of strain along the contour of a single-cell cavity made of ingot Nb subjected to increasing uniform differential pressure, up to 6 atm. The data were used to infer mechanical properties of this material after cavity fabrication, by comparison with the results from simulation calculations done with ANSYS. The objective is to provide useful information about the mechanical properties of ingot Nb cavities which can be used in the design phase of SRF cavities intended to be built with this material.

  8. Resonant MEMS tunable VCSEL

    DEFF Research Database (Denmark)

    Ansbæk, Thor; Chung, Il-Sug; Semenova, Elizaveta;

    2013-01-01

    We demonstrate how resonant excitation of a microelectro-mechanical system can be used to increase the tuning range of a vertical-cavity surface-emitting laser two-fold by enabling both blue- and red-shifting of the wavelength. In this way a short-cavity design enabling wide tuning range can be r...

  9. Tailoring the negative-refractive-index metamaterials composed of semiconductor-metal-semiconductor gold ring/disk cavity heptamers to support strong Fano resonances in the visible spectrum.

    Science.gov (United States)

    Ahmadivand, Arash; Pala, Nezih

    2015-02-01

    In this study, we investigated numerically the plasmon response of a planar negative-index metamaterial composed of symmetric molecular orientations of Au ring/disk nanocavities in a heptamer cluster. Using the plasmon hybridization theory and considering the optical response of an individual nanocluster, we determined the accurate geometrical sizes for a ring/disk nanocavity heptamer. It is shown that the proposed well-organized nanocluster can be tailored to support strong and sharp Fano resonances in the visible spectrum. Surrounding and filling the heptamer clusters by various metasurfaces with different chemical characteristics, and illuminating the structure with an incident light source, we proved that this configuration reflects low losses and isotropic features, including a pronounced Fano dip in the visible spectrum. Technically, employing numerical methods and tuning the geometrical sizes of the structure, we tuned and induced the Fano dip in the visible range, while the dark and bright plasmon resonance extremes are blueshifted to shorter wavelengths dramatically. Considering the calculated transmission window, we quantified the effective refractive index for the structure, while the substance of the substrate material was varied. Using Si, GaP, and InP semiconductors as substrate materials, we calculated and compared the corresponding figure of merit (FOM) for different regimes. The highest possible FOM was obtained for the GaP-Au-GaP negative-refractive-index metamaterial composed of ring/disk nanocavity heptamers as 62.4 at λ∼690  nm (arounnd the position of the Fano dip). Despite the outstanding symmetric nature of the suggested heptamer array, we provided sharp Fano dips by the appropriate tuning of the geometrical and chemical parameters. This study yields a method to employ ring/disk nanocavity heptamers as a negative-refractive-index metamaterial in designing highly accurate localization of surface plasmon resonance sensing devices and

  10. Geometric Stochastic Resonance

    CERN Document Server

    Ghosh, Pulak Kumar; Savel'ev, Sergey E; Nori, Franco

    2015-01-01

    A Brownian particle moving across a porous membrane subject to an oscillating force exhibits stochastic resonance with properties which strongly depend on the geometry of the confining cavities on the two sides of the membrane. Such a manifestation of stochastic resonance requires neither energetic nor entropic barriers, and can thus be regarded as a purely geometric effect. The magnitude of this effect is sensitive to the geometry of both the cavities and the pores, thus leading to distinctive optimal synchronization conditions.

  11. Frequency combs for cavity cascades: OPO combs and graphene-coupled cavities

    Science.gov (United States)

    Lee, Kevin F.; Kowzan, Grzegorz; Lee, C.-C.; Mohr, C.; Jiang, Jie; Schunemann, Peter G.; Schibli, T. R.; Maslowski, Piotr; Fermann, M. E.

    2017-01-01

    Frequency combs can be used directly, for example as a highly precise spectroscopic light source. They can also be used indirectly, as a bridge between devices whose high precision requirements would normally make them incompatible. Here, we demonstrate two ways that a frequency comb enables new technologies by matching optical cavities. One cavity is the laser oscillator. A second cavity is a low-threshold doubly-resonant optical parametric oscillator (OPO). Extending optical referencing to the doubly-resonant OPO turns the otherwise unstable device into an extremely precise midinfrared frequency comb. Another cavity is an optical enhancement cavity for amplifying spectral absorption in a gas. With the high speed of a graphene-modulated frequency comb, we can couple a frequency comb directly into a high-finesse cavity for trace gas detection.

  12. Circuit QED with 3D cavities

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Edwar; Baust, Alexander; Zhong, Ling; Gross, Rudolf [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany); Physik-Department, TU Muenchen, Garching (Germany); Nanosystems Initiative Munich (NIM), Muenchen (Germany); Anderson, Gustav; Wang, Lujun; Eder, Peter; Fischer, Michael; Goetz, Jan; Haeberlein, Max; Schwarz, Manuel; Wulschner, Karl Friedrich; Deppe, Frank; Fedorov, Kirill; Huebl, Hans; Menzel, Edwin [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany); Physik-Department, TU Muenchen, Garching (Germany); Marx, Achim [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany)

    2015-07-01

    In typical circuit QED systems on-chip superconducting qubits are coupled to integrated coplanar microwave resonators. Due to the planar geometry, the resonators are often a limiting factor regarding the total coherence of the system. Alternatively, similar hybrid systems can be realized using 3D microwave cavities. Here, we present design considerations for the 3D microwave cavity as well as the superconducting transmon qubit. Moreover, we show experimental data of a high purity aluminum cavity demonstrating quality factors above 1.4 .10{sup 6} at the single photon level and a temperature of 50 mK. Our experiments also demonstrate that the quality factor is less dependent on the power compared to planar resonator geometries. Furthermore, we present strategies for tuning both the cavity and the qubit individually.

  13. Plasmonic Coupled Cavities on Moire Surfaces

    Science.gov (United States)

    Balci, Sinan; Kocabas, Askin; Karabiyik, Mustafa; Kocabas, Coskun; Aydinli, Atilla

    2010-03-01

    We investigate surface plasmon polariton (SPP) coupled cavity modes on Moire surfaces. An experimental study has been made of the propagation of SPPs on a thin silver surface that is textured with Moire surface pattern using interference lithography. The Moire surface contains periodic array of one dimensional cavities. The distance between the cavities can be controlled by changing the periodicities of Moire surface. When the SPP cavity separation is sufficiently small, we show splitting of strongly coupled plasmonic cavity modes through numerical simulations. Conversely, when the SPP cavity separation is sufficiently large, SPP cavity modes are found to be localized and do not show splitting of SPP cavity modes . This splitting of SPP cavity modes are well explained with a tight binding model that has been succesfully applied in photonic coupled cavities. Reflection measurements and numerical simulation of a large number of adjacent SPP cavities have shown a coupled resonator optical waveguide (CROW) type plasmonic waveguide band formation within the band gap region of unperturbed uniform grating.

  14. The emission properties of an atom inside a cavity when manipulating the atoms outside the cavity

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wen; YE Liu; XIONG Kuang-wei; ZHANG Jin

    2003-01-01

    Considering three two-level atoms initially in the GHZ state, then one atom of them is put into an initially empty cavity and made resonant interaction. It is shown that the emission properties of the atom inside the cavity can be affected only when both of the atoms outside the cavity have been manipulated. This conclusion can also be generalized to n two-level atoms.

  15. Nanozeolite-LTL with Gd(III) deposited in the large and Eu(III) in the small cavities as a magnetic resonance optical imaging probe.

    Science.gov (United States)

    Mayer, Florian; Zhang, Wuyuan; Brichart, Thomas; Tillement, Olivier; Bonnet, Célia S; Tóth, Éva; Peters, Joop A; Djanashvili, Kristina

    2014-03-17

    The immense structural diversity of more than 200 known zeolites is the basis for the wide variety of applications of these fascinating materials ranging from catalysis and molecular filtration to agricultural uses. Despite this versatility, the potential of zeolites in medical imaging has not yet been much exploited. In this work a novel strategy is presented to selectively deposit different ions into distinct framework locations of zeolite-LTL (Linde type L) and it is demonstrated that the carefully ion-exchanged Gd/Eu-containing nanocrystals acquire exceptional magnetic properties in combination with enhanced luminescence. This smart exploitation of the framework structure yields the highest relaxivity density (13.7 s(-1)  L g(-1) at 60 MHz and 25 °C) reported so far for alumosilicates, rendering these materials promising candidates for the design of dual magnetic resonance/optical imaging probes, as demonstrated in preliminary phantom studies.

  16. Efficient generation of Bell-cat states in remote cavities

    Institute of Scientific and Technical Information of China (English)

    LI Xing; ZHANG Ying-Jie; XIA Yun-Jie

    2008-01-01

    In the context of cavity quantum electrodynamics (QED), a potential scheme is proposed to generate entangled coherentstates. The scheme includes twice interactions of two-level atoms with cavities. In the first interaction, two atoms are sentinto a microwave cavity with the large detuning respectively. And then the second interaction is that the two atoms enteranother microwave cavity and are driven by a resonant classical field meantime. When we choose the proper interactiontime and make measurement on the two atoms, the two microwave cavity mode fields are determinatively entangled. Inaddition, it is easy to generalize the scheme to multi-cavity and multi-atom.

  17. A micropillar for cavity optomechanics

    Energy Technology Data Exchange (ETDEWEB)

    Kuhn, Aurélien; Neuhaus, Leonhard; Deléglise, Samuel; Briant, Tristan; Cohadon, Pierre-François; Heidmann, Antoine [Laboratoire Kastler Brossel, UPMC-ENS-CNRS, Paris (France); Van Brackel, Emmanuel [Département de Physique, ENS, Paris (France); Chartier, Claude; Ducloux, Olivier; Le Traon, Olivier [Département Mesures Physiques, ONERA, Châtillon (France); Michel, Christophe; Pinard, Laurent; Flaminio, Raffaele [Laboratoire des Matériaux Avancés, IN2P3-CNRS, Lyon (France)

    2014-12-04

    Demonstrating the quantum ground state of a macroscopic mechanical object is a major experimental challenge in physics, at the origin of the rapid emergence of cavity optomechanics. We have developed a new generation of optomechanical devices, based on a microgram quartz micropillar with a very high mechanical quality factor. The structure is used as end mirror in a Fabry-Perot cavity with a high optical finesse, leading to ultra-sensitive interferometric measurement of the resonator displacement. We expect to reach the ground state of this optomechanical resonator by combining cryogenic cooling in a dilution fridge at 30 mK and radiation-pressure cooling. We have already carried out a quantum-limited measurement of the micropillar thermal noise at low temperature.

  18. The ADMX Microwave Cavity: Present and future

    Science.gov (United States)

    Woollett, Nathan; ADMX Collaboration

    2017-01-01

    The Axion Dark Matter eXperiment (ADMX), a direct-detection axion search, uses a tunable resonant cavity to enhance axion to photon conversion rates to a detectable level when the cavity resonance matches the mass of the axion. It has successfully taken data in the 460 - 890 MHz frequency range and is now probing a similar range with much higher sensitivity. However the axion mass is unknown and may be at higher frequencies than the currently operating system. In anticipation of future runs with an increased mass range, ADMX is conducting extensive research and development of microwave cavities. These developments include photonic band-gap cavities, multi-vane cavities, partitioned cavities, in-phase coupled cavities, and superconducting hybrid cavities. Many of these projects are in different stages between simulations and testing of physical prototypes. The status and current objectives of these projects will be presented. Supported by DOE Grants DE-SC0010280, DE-FG02-96ER40956, DE-AC52-07NA27344, DE-AC03-76SF00098, the Heising-Simons Foundation and the LLNL, FNAL and PNNL LDRD program.

  19. Dynamical tunneling in optical cavities

    CERN Document Server

    Hackenbroich, G; Hackenbroich, Gregor; Noeckel, Jens U.

    1998-01-01

    The lifetime of whispering gallery modes in a dielectric cavity with a metallic inclusion is shown to fluctuate by orders of magnitude when size and location of the inclusion are varied. We ascribe these fluctuations to tunneling transitions between resonances quantized in different regions of phase space. This interpretation is confirmed by a comparison of the classical phase space structure with the Husimi distribution of the resonant modes. A model Hamiltonian is introduced that describes the phenomenon and shows that it can be expected in a more general class of systems.

  20. R-matrix theory of driven electromagnetic cavities.

    Science.gov (United States)

    Beck, F; Dembowski, C; Heine, A; Richter, A

    2003-06-01

    The resonances of cylindrical symmetric microwave cavities are analyzed in R-matrix theory, which transforms the input channel conditions to the output channels. Single and interfering double resonances are studied and compared with experimental results obtained with superconducting microwave cavities. Because of the equivalence of the two-dimensional Helmholtz and the stationary Schrödinger equations, the results give insight into the resonance structure of regular and chaotic quantum billiards.

  1. Composite Resonator Surface Emitting Lasers

    Energy Technology Data Exchange (ETDEWEB)

    FISCHER,ARTHUR J.; CHOQUETTE,KENT D.; CHOW,WENG W.; ALLERMAN,ANDREW A.; GEIB,KENT M.

    2000-05-01

    The authors have developed electrically-injected coupled-resonator vertical-cavity lasers and have studied their novel properties. These monolithically grown coupled-cavity structures have been fabricated with either one active and one passive cavity or with two active cavities. All devices use a selectively oxidized current aperture in the lower cavity, while a proton implant was used in the active-active structures to confine current in the top active cavity. They have demonstrated optical modulation from active-passive devices where the modulation arises from dynamic changes in the coupling between the active and passive cavities. The laser intensity can be modulated by either forward or reverse biasing the passive cavity. They have also observed Q-switched pulses from active-passive devices with pulses as short as 150 ps. A rate equation approach is used to model the Q-switched operation yielding good agreement between the experimental and theoretical pulseshape. They have designed and demonstrated the operation of active-active devices which la.se simultaneously at both longitudinal cavity resonances. Extremely large bistable regions have also been observed in the light-current curves for active-active coupled resonator devices. This bistability can be used for high contrast switching with contrast ratios as high as 100:1. Coupled-resonator vertical-cavity lasers have shown enhanced mode selectivity which has allowed devices to lase with fundamental-mode output powers as high as 5.2 mW.

  2. Cavity Mode Frequencies and Large Optomechanical Coupling in Two-Membrane Cavity Optomechanics

    CERN Document Server

    Li, J; Malossi, N; Vitali, D

    2015-01-01

    We study the cavity mode frequencies of a Fabry-Perot cavity containing two vibrating dielectric membranes and the corresponding optomechanical coupling. Due to optical interference, extremely large optomechanical coupling of the membrane relative motion is achieved when the two membranes are placed very close to a resonance of the inner cavity formed by the two membranes, and in the limit of highly reflective membranes. The upper bound of the coupling strength is given by the optomechanical coupling associated with the much shorter inner cavity, consistently with the analysis of A. Xuereb et al., Phys. Rev. Lett. 109, 223601 (2012).

  3. Effects of mode degeneracy in the LIGO Livingston Observatory recycling cavity

    CERN Document Server

    Gretarsson, Andri M; Frolov, Valery; O'Reilly, Brian; Fritschel, Peter K

    2007-01-01

    We analyze the electromagnetic fields in a Pound-Drever-Hall locked, marginally unstable, Fabry-Perot cavity as a function of small changes in the cavity length during resonance. More specifically, we compare the results of a detailed numerical model with the behavior of the recycling cavity of the Laser Interferometer Gravitational-wave Observatory (LIGO) detector that is located in Livingston, Louisiana. In the interferometer's normal mode of operation, the recycling cavity is stabilized by inducing a thermal lens in the cavity mirrors with an external CO2 laser. During the study described here, this thermal compensation system was not operating, causing the cavity to be marginally optically unstable and cavity modes to become degenerate. In contrast to stable optical cavities, the modal content of the resonating beam in the uncompensated recycling cavity is significantly altered by very small cavity length changes. This modifies the error signals used to control the cavity length in such a way that the zer...

  4. Structural design of microwave coaxial resonant cavity sensor for liquid film thickness measurement%用于液膜厚度测量的开式同轴腔传感器结构设计

    Institute of Scientific and Technical Information of China (English)

    钱江波; 严晓哲; 韩中合

    2015-01-01

    Dragged by high speed steam flow,the water film at wet-steam region in steam turbine low pressure cylin-der will form large droplets,causing serious water erosion of rotor blade.Real-time monitoring on liquid film thick-ness has great significance on rotor blade protection and unit safe operation.Thus,equivalent circuit of resonant cav-ity was built up.On this basis,the mathematical model of water film thickness measurement was established and the thickness measurement equation was deduced.The opening coaxial resonant cavity with good electromagnetic per-formance was designed.By using the HFSS software,the relationship between water film thickness and resonance frequency was analyzed,and the undetermined coefficients of thickness measurement equation were determined. Simulation on distilled water film whose dielectric constant is 81 shows that,when the water film thickness increases from 0 mm to 1 mm (with step of 0.02),the fitting similarity is 0.995 and the mean square error is 0.022.There-fore,this measurement formula has high reliability,which can be used to measure the liquid film thickness for static blades,cylinder walls,guide rings and other places.%汽轮机低压缸的湿蒸汽区液膜在高速汽流拖拽撕裂下形成较大水滴,会造成动叶片的严重水蚀,实时监测液膜厚度对于叶片防护及机组的安全运行具有重要意义。对此,搭建了谐振腔等效电路,并推导液膜厚度的测量关系式,设计了电磁性能良好的开式同轴谐振腔传感器,仿真分析了同轴腔的谐振频率随水膜厚度的变化关系,确定了测量关系式中的待定系数;选择蒸馏水为液膜材料,介电常数为81,利用电磁仿真软件 HFSS 计算水膜厚度 h 从0变化到1 mm,单位增加0.02 mm 时进行拟合仿真,结果表明:拟合相似度0.995,均方根误差0.022。可见,该测量关系式可靠性较高,该测量技术可用于测量汽轮机静叶片、汽缸壁、

  5. A Scanning Cavity Microscope

    CERN Document Server

    Mader, Matthias; Hänsch, Theodor W; Hunger, David

    2014-01-01

    Imaging of the optical properties of individual nanosystems beyond fluorescence can provide a wealth of information. However, the minute signals for absorption and dispersion are challenging to observe, and only specialized techniques requiring sophisticated noise rejection are available. Here we use signal enhancement in a scanning optical microcavity to demonstrate ultra-sensitive imaging. Harnessing multiple interactions of probe light with a sample within an optical resonator, we achieve a 1700-fold signal enhancement compared to diffraction-limited microscopy. We demonstrate quantitative imaging of the extinction cross section of gold nanoparticles with a sensitivity below 1 nm2, we show a method to improve spatial resolution potentially below the diffraction limit by using higher order cavity modes, and we present measurements of the birefringence and extinction contrast of gold nanorods. The demonstrated simultaneous enhancement of absorptive and dispersive signals promises intriguing potential for opt...

  6. Cavity-enhanced spectroscopy and sensing

    CERN Document Server

    Loock, Hans-Peter

    2014-01-01

    The book reviews the dramatic recent advances in the use of optical resonators for high sensitivity and high resolution molecular spectroscopy as well as for chemical, mechanical and physical sensing.  It encompasses a variety of cavities including those made of two or more mirrors, optical fiber loops, fiber gratings and spherical cavities. The book focuses on novel techniques and their applications. Each chapter is written by an expert and/or pioneer in the field. These experts also provide the theoretical background in optics and molecular physics where needed. Examples of recent breakthroughs include the use of frequency combs (Nobel prize 2005) for cavity enhanced sensing and spectroscopy, the use of novel cavity materials and geometries, the development of optical heterodyne detection techniques combined to active frequency-locking schemes. These methods allow the use and interrogation of optical resonators with a variety of coherent light sources for trace gas detection and sensing of strain, temperat...

  7. Applications of cavity optomechanics

    Energy Technology Data Exchange (ETDEWEB)

    Metcalfe, Michael [Booz Allen Hamilton, 3811 Fairfax Drive, Arlington, Virginia 22203 (United States)

    2014-09-15

    Cavity-optomechanics” aims to study the quantum properties of mechanical systems. A common strategy implemented in order to achieve this goal couples a high finesse photonic cavity to a high quality factor mechanical resonator. Then, using feedback forces such as radiation pressure, one can cool the mechanical mode of interest into the quantum ground state and create non-classical states of mechanical motion. On the path towards achieving these goals, many near-term applications of this field have emerged. After briefly introducing optomechanical systems and describing the current state-of-the-art experimental results, this article summarizes some of the more exciting practical applications such as ultra-sensitive, high bandwidth accelerometers and force sensors, low phase noise x-band integrated microwave oscillators and optical signal processing such as optical delay-lines, wavelength converters, and tunable optical filters. In this rapidly evolving field, new applications are emerging at a fast pace, but this article concentrates on the aforementioned lab-based applications as these are the most promising avenues for near-term real-world applications. New basic science applications are also becoming apparent such as the generation of squeezed light, testing gravitational theories and for providing a link between disparate quantum systems.

  8. Applications of cavity optomechanics

    Science.gov (United States)

    Metcalfe, Michael

    2014-09-01

    "Cavity-optomechanics" aims to study the quantum properties of mechanical systems. A common strategy implemented in order to achieve this goal couples a high finesse photonic cavity to a high quality factor mechanical resonator. Then, using feedback forces such as radiation pressure, one can cool the mechanical mode of interest into the quantum ground state and create non-classical states of mechanical motion. On the path towards achieving these goals, many near-term applications of this field have emerged. After briefly introducing optomechanical systems and describing the current state-of-the-art experimental results, this article summarizes some of the more exciting practical applications such as ultra-sensitive, high bandwidth accelerometers and force sensors, low phase noise x-band integrated microwave oscillators and optical signal processing such as optical delay-lines, wavelength converters, and tunable optical filters. In this rapidly evolving field, new applications are emerging at a fast pace, but this article concentrates on the aforementioned lab-based applications as these are the most promising avenues for near-term real-world applications. New basic science applications are also becoming apparent such as the generation of squeezed light, testing gravitational theories and for providing a link between disparate quantum systems.

  9. Fabrication of elliptical SRF cavities

    Science.gov (United States)

    Singer, W.

    2017-03-01

    The technological and metallurgical requirements of material for high-gradient superconducting cavities are described. High-purity niobium, as the preferred metal for the fabrication of superconducting accelerating cavities, should meet exact specifications. The content of interstitial impurities such as oxygen, nitrogen, and carbon must be below 10 μg g-1. The hydrogen content should be kept below 2 μg g-1 to prevent degradation of the quality factor (Q-value) under certain cool-down conditions. The material should be free of flaws (foreign material inclusions or cracks and laminations) that can initiate a thermal breakdown. Traditional and alternative cavity mechanical fabrication methods are reviewed. Conventionally, niobium cavities are fabricated from sheet niobium by the formation of half-cells by deep drawing, followed by trim machining and electron beam welding. The welding of half-cells is a delicate procedure, requiring intermediate cleaning steps and a careful choice of weld parameters to achieve full penetration of the joints. A challenge for a welded construction is the tight mechanical and electrical tolerances. These can be maintained by a combination of mechanical and radio-frequency measurements on half-cells and by careful tracking of weld shrinkage. The main aspects of quality assurance and quality management are mentioned. The experiences of 800 cavities produced for the European XFEL are presented. Another cavity fabrication approach is slicing discs from the ingot and producing cavities by deep drawing and electron beam welding. Accelerating gradients at the level of 35-45 MV m-1 can be achieved by applying electrochemical polishing treatment. The single-crystal option (grain boundary free) is discussed. It seems that in this case, high performance can be achieved by a simplified treatment procedure. Fabrication of the elliptical resonators from a seamless pipe as an alternative is briefly described. This technology has yielded good

  10. Injection-controlled laser resonator

    Science.gov (United States)

    Chang, J.J.

    1995-07-18

    A new injection-controlled laser resonator incorporates self-filtering and self-imaging characteristics with an efficient injection scheme. A low-divergence laser signal is injected into the resonator, which enables the injection signal to be converted to the desired resonator modes before the main laser pulse starts. This injection technique and resonator design enable the laser cavity to improve the quality of the injection signal through self-filtering before the main laser pulse starts. The self-imaging property of the present resonator reduces the cavity induced diffraction effects and, in turn, improves the laser beam quality. 5 figs.

  11. Different optical properties in different periodic slot cavity geometrical morphologies

    Science.gov (United States)

    Zhou, Jing; Shen, Meng; Du, Lan; Deng, Caisong; Ni, Haibin; Wang, Ming

    2016-09-01

    In this paper, optical properties of two-dimensional periodic annular slot cavity arrays in hexagonal close-packing on a silica substrate are theoretically characterized by finite difference time domain (FDTD) simulation method. By simulating reflectance spectra, electric field distribution, and charge distribution, we confirm that multiple cylindrical surface plasmon resonances can be excited in annular inclined slot cavities by linearly polarized light, in which the four reflectance dips are attributed to Fabry-Perot cavity resonances in the coaxial cavity. A coaxial waveguide mode TE11 will exist in these annular cavities, and the wavelengths of these reflectance dips are effectively tailored by changing the geometrical pattern of slot cavity and the dielectric materials filled in the cavities. These resonant wavelengths are localized in annular cavities with large electric field enhancement and dissipate gradually due to metal loss. The formation of an absorption peak can be explained from the aspect of phase matching conditions. We observed that the proposed structure can be tuned over the broad spectral range of 600-4000 nm by changing the outer and inner radii of the annular gaps, gap surface topography. Meanwhile, different lengths of the cavity may cause the shift of resonance dips. Also, we study the field enhancement at different vertical locations of the slit. In addition, dielectric materials filling in the annular gaps will result in a shift of the resonance wavelengths, which make the annular cavities good candidates for refractive index sensors. The refractive index sensitivity of annular cavities can also be tuned by the geometry size and the media around the cavity. Annular cavities with novel applications can be implied as surface enhanced Raman spectra substrates, refractive index sensors, nano-lasers, and optical trappers. Project supported by the National Natural Science Foundation of China (Grant No. 61178044), the Natural Science Foundation

  12. Cavity QED with Multiple Hyperfine Levels

    CERN Document Server

    Birnbaum, K M; Kimble, H J

    2006-01-01

    We calculate the weak-driving transmission of a linearly polarized cavity mode strongly coupled to the D2 transition of a single Cesium atom. Results are relevant to future experiments with microtoroid cavities, where the single-photon Rabi frequency g exceeds the excited-state hyperfine splittings, and photonic bandgap resonators, where g is greater than both the excited- and ground-state splitting.

  13. Manipulating nanoscale atom-atom interactions with cavity QED

    CERN Document Server

    Pal, Arpita; Deb, Bimalendu

    2016-01-01

    We theoretically explore manipulation of interactions between excited and ground state atoms at nanoscale separations by cavity quantum electrodynamics (CQED). We develop an adiabatic molecular dressed state formalism and show that it is possible to generate Fano-Feshbach resonances between ground and long-lived excited-state atoms inside a cavity. The resonances are shown to arise due to non-adiabatic coupling near a pseudo-crossing between the dressed state potentials. We illustrate our results with a model study using fermionic $^{171}$Yb atoms in a two-modal cavity. Our study is important for manipulation of interatomic interactions at low energy by cavity field.

  14. Nylon Sleeve for Cavity Amplifier Holds Tuning Despite Heat

    Science.gov (United States)

    Derr, Lloyd

    1964-01-01

    The problem: Detuning of cavity amplifiers with change in temperature. This results in deterioration of the performance of the amplifier at its design frequency. In cavity amplifiers and filters it is desirable that constant performance be maintained regardless of thermal changes. These changes often cause an "off resonance shift" in a cavity filter and a deterioration of performance in a cavity amplifier. The solution: Mount the tuning probe in a nylon sleeve. Thermal expansion and contraction of the nylon nullifies unwanted capacitive and inductive changes in the resonant elements.

  15. Cavity cooling below the recoil limit.

    Science.gov (United States)

    Wolke, Matthias; Klinner, Julian; Keßler, Hans; Hemmerich, Andreas

    2012-07-06

    Conventional laser cooling relies on repeated electronic excitations by near-resonant light, which constrains its area of application to a selected number of atomic species prepared at moderate particle densities. Optical cavities with sufficiently large Purcell factors allow for laser cooling schemes, avoiding these limitations. Here, we report on an atom-cavity system, combining a Purcell factor above 40 with a cavity bandwidth below the recoil frequency associated with the kinetic energy transfer in a single photon scattering event. This lets us access a yet-unexplored regime of atom-cavity interactions, in which the atomic motion can be manipulated by targeted dissipation with sub-recoil resolution. We demonstrate cavity-induced heating of a Bose-Einstein condensate and subsequent cooling at particle densities and temperatures incompatible with conventional laser cooling.

  16. Optomechanical photon shuttling between photonic cavities

    CERN Document Server

    Li, Huan

    2014-01-01

    Mechanical motion of photonic devices driven by optical forces provides a profound means of coupling between optical fields. The current focus of these optomechanical effects has been on cavity optomechanics systems in which co-localized optical and mechanical modes interact strongly to enable wave-mixing between photons and phonons and backaction cooling of mechanical modes. Alternatively, extended mechanical modes can also induce strong nonlocal effects on propagating optical fields or multiple localized optical modes at distances. Here, we demonstrate a novel multi-cavity optomechanical device: a "photon see-saw", in which torsional optomechanical motion can shuttle photons between two photonic crystal nanocavities. The resonance frequencies of the two cavities, one on each side of the see-saw, are modulated anti-symmetrically by the device's rotation. Pumping photons into one cavity excites optomechanical self-oscillation which strongly modulates the inter-cavity coupling and shuttles photons to the other...

  17. Optomechanical photon shuttling between photonic cavities.

    Science.gov (United States)

    Li, Huan; Li, Mo

    2014-11-01

    Mechanical motion of photonic devices driven by optical forces provides a profound means of coupling between optical fields. The current focus of these optomechanical effects has been on cavity optomechanics systems in which co-localized optical and mechanical modes interact strongly to enable wave mixing between photons and phonons, and backaction cooling of mechanical modes. Alternatively, extended mechanical modes can also induce strong non-local effects on propagating optical fields or multiple localized optical modes at distances. Here, we demonstrate a multicavity optomechanical device in which torsional optomechanical motion can shuttle photons between two photonic crystal nanocavities. The resonance frequencies of the two cavities, one on each side of this 'photon see-saw', are modulated antisymmetrically by the device's rotation. Pumping photons into one cavity excites optomechanical self-oscillation, which strongly modulates the inter-cavity coupling and shuttles photons to the other empty cavity during every oscillation cycle in a well-regulated fashion.

  18. Dispersion of coupled mode-gap cavities

    CERN Document Server

    Lian, Jin; Yüce, Emre; De Rossi, Sylvain Combrié Alfredo; Mosk, Allard P

    2015-01-01

    The dispersion of a CROW made of photonic crystal mode-gap cavities is pronouncedly asymmetric. This asymmetry cannot be explained by the standard tight binding model. We show that the fundamental cause of the asymmetric dispersion is the fact that the cavity mode profile itself is dispersive, i.e., the mode wave function depends on the driving frequency, not the eigenfrequency. This occurs because the photonic crystal cavity resonances do not form a complete set. By taking into account the dispersive mode profile, we formulate a mode coupling model that accurately describes the asymmetric dispersion without introducing any new free parameters.

  19. LHC Crab Cavity Coupler Test Boxes

    CERN Document Server

    Mitchell, James; Burt, Graeme; Calaga, Rama; Macpherson, Alick; Montesinos, Eric; Silva, Subashini; Tutte, Adam; Xiao, Binping

    2016-01-01

    The LHC double quarter wave (DQW) crab cavities have two different types of Higher Order Mode (HOM) couplers in addition to a fundamental power coupler (FPC). The FPC requires conditioning, so to achieve this we have designed a radio-frequency (RF) quarter wave resonator to provide high transmission between two opposing FPCs. For the HOM couplers we must ensure that the stop-band filter is positioned at the cavity frequency and that peak transmission occurs at the same frequencies as the strongest HOMs. We have designed two test boxes which preserve the cavity spectral response in order to test the couplers.

  20. Crab Cavity Development

    CERN Document Server

    Calaga, R; Burt, G; Ratti, A

    2015-01-01

    The HL-LHC upgrade will use deflecting (or crab) cavities to compensate for geometric luminosity loss at low β* and non-zero crossing angle. A local scheme with crab cavity pairs across the IPs is used employing compact crab cavities at 400 MHz. Design of the cavities, the cryomodules and the RF system is well advanced. The LHC crab cavities will be validated initially with proton beam in the SPS.

  1. Quantum Dot-Photonic Crystal Cavity QED Based Quantum Information Processing

    Science.gov (United States)

    2012-08-14

    Physical Review A, 2012] 3. Study of the off-resonant quantum dot-cavity coupling in solid-state cavity QED system, and the phonon mediated off...resonant interaction between two quantum dots [Majumdar et al., Physical Review B , 2012] 4. Coherent optical spectroscopy of a single quantum dot via an off...Resonant cavity - much simpler than in conventional approaches [Majumdar et al, Physical Review B, 2011; Papageorge et al., New. Journal of Physics

  2. Seismic wave interaction with underground cavities

    Science.gov (United States)

    Schneider, Felix M.; Esterhazy, Sofi; Perugia, Ilaria; Bokelmann, Götz

    2016-04-01

    Realization of the future Comprehensive Nuclear Test Ban Treaty (CTBT) will require ensuring its compliance, making the CTBT a prime example of forensic seismology. Following indications of a nuclear explosion obtained on the basis of the (IMS) monitoring network further evidence needs to be sought at the location of the suspicious event. For such an On-Site Inspection (OSI) at a possible nuclear test site the treaty lists several techniques that can be carried out by the inspection team, including aftershock monitoring and the conduction of active seismic surveys. While those techniques are already well established, a third group of methods labeled as "resonance seismometry" is less well defined and needs further elaboration. A prime structural target that is expected to be present as a remnant of an underground nuclear explosion is a cavity at the location and depth the bomb was fired. Originally "resonance seismometry" referred to resonant seismic emission of the cavity within the medium that could be stimulated by an incident seismic wave of the right frequency and observed as peaks in the spectrum of seismic stations in the vicinity of the cavity. However, it is not yet clear which are the conditions for which resonant emissions of the cavity could be observed. In order to define distance-, frequency- and amplitude ranges at which resonant emissions could be observed we study the interaction of seismic waves with underground cavities. As a generic model for possible resonances we use a spherical acoustic cavity in an elastic full-space. To solve the forward problem for the full elastic wave field around acoustic spherical inclusions, we implemented an analytical solution (Korneev, 1993). This yields the possibility of generating scattering cross-sections, amplitude spectrums and synthetic seismograms for plane incident waves. Here, we focus on the questions whether or not we can expect resonant responses in the wave field scattered from the cavity. We show

  3. Optomechanical damping of a nanomembrane inside an optical ring cavity

    CERN Document Server

    Yilmaz, Arzu; Wolf, Philip; Schmidt, Dag; Eisele, Max; Zimmermann, Claus; Slama, Sebastian

    2016-01-01

    We experimentally and theoretically investigate mechanical nanooscillators coupled to the light in an optical ring resonator made of dielectric mirrors. We identify an optomechanical damping mechanism that is fundamentally different to the well known cooling in standing wave cavities. While, in a standing wave cavity the mechanical oscillation shifts the resonance frequency of the cavity in a ring resonator the frequency does not change. Instead the position of the nodes is shifted with the mechanical excursion. We derive the damping rates and test the results experimentally with a silicon-nitride nanomembrane. It turns out that scattering from small imperfections of the dielectric mirror coatings has to be taken into account to explain the value of the measured damping rate. We extend our theoretical model and regard a second reflector in the cavity that captures the effects of mirror back scattering. This model can be used to also describe the situation of two membranes that both interact with the cavity fi...

  4. Squeezing-enhanced measurement sensitivity in a cavity optomechanical system

    DEFF Research Database (Denmark)

    Kerdoncuff, Hugo; Hoff, Ulrich Busk; Harris, Glen I.;

    2015-01-01

    We determine the theoretical limits to squeezing-enhanced measurement sensitivity of mechanical motion in a cavity optomechanical system. The motion of a mechanical resonator is transduced onto quadrature fluctuations of a cavity optical field and a measurement is performed on the optical field e...

  5. Quantum search via superconducting quantum interference devices in a cavity

    Institute of Scientific and Technical Information of China (English)

    Lu Yan; Dong Ping; Xue Zheng-Yuan; Cao Zhuo-Liang

    2007-01-01

    We propose a scheme for implementing the Grover search algorithm with two superconducing quantum interference devices (SQUIDs) in a cavity. Our scheme only requires single resonant interaction of the SQUID-cavity system and the required interaction time is very short. The simplicity of the process and the reduction of the interaction time are important for restraining decoherence.

  6. Coherent acoustic excitation of cavity polaritons

    DEFF Research Database (Denmark)

    Poel, Mike van der; de Lima, M. M.; Hey, R.

    and highly nonlinear optical response.Our sample consists of epitaxially grown GaAs/AlGaAs QWs located at the anti-node ofa high Q lambda cavity, which is resonant with the QW excitonic transition3. The SAWfield, which is excited by an interdigital transducer on the piezoelectric GaAs samplesurface...

  7. All-optical tunable photonic crystal cavity

    DEFF Research Database (Denmark)

    Pu, Minhao; Liu, Liu; Ou, Haiyan;

    2010-01-01

    We demonstrate an ultra-small photonic crystal cavity with two resonant modes. An all-optical tuning operation based on the free-carrier plasma effect is, for the first time, realized utilizing a continuous wave light source. The termo-optical effect is minimized by isoproponal infiltration...... of the photonic crystal structure....

  8. Plasmonic coaxial waveguide-cavity devices.

    Science.gov (United States)

    Mahigir, Amirreza; Dastmalchi, Pouya; Shin, Wonseok; Fan, Shanhui; Veronis, Georgios

    2015-08-10

    We theoretically investigate three-dimensional plasmonic waveguide-cavity structures, built by side-coupling stub resonators that consist of plasmonic coaxial waveguides of finite length, to a plasmonic coaxial waveguide. The resonators are terminated either in a short or an open circuit. We show that the properties of these waveguide-cavity systems can be accurately described using a single-mode scattering matrix theory. We also show that, with proper choice of their design parameters, three-dimensional plasmonic coaxial waveguide-cavity devices and two-dimensional metal-dielectric-metal devices can have nearly identical transmission spectra. Thus, three-dimensional plasmonic coaxial waveguides offer a platform for practical implementation of two-dimensional metal-dielectric-metal device designs.

  9. Coupled external cavity photonic crystal enhanced fluorescence.

    Science.gov (United States)

    Pokhriyal, Anusha; Lu, Meng; Ge, Chun; Cunningham, Brian T

    2014-05-01

    We report a fundamentally new approach to enhance fluorescence in which surface adsorbed fluorophore-tagged biomolecules are excited on a photonic crystal surface that functions as a narrow bandwidth and tunable mirror of an external cavity laser. This scheme leads to ∼10× increase in the electromagnetic enhancement factor compared to ordinary photonic crystal enhanced fluorescence. In our experiments, the cavity automatically tunes its lasing wavelength to the resonance wavelength of the photonic crystal, ensuring optimal on-resonance coupling even in the presence of variable device parameters and variations in the density of surface-adsorbed capture molecules. We achieve ∼10(5) × improvement in the limit of detection of a fluorophore-tagged protein compared to its detection on an unpatterned glass substrate. The enhanced fluorescence signal and easy optical alignment make cavity-coupled photonic crystals a viable approach for further reducing detection limits of optically-excited light emitters that are used in biological assays.

  10. Two simple schemes for implementing Toffoli gate via atom-cavity field interaction in cavity quantum electrodynamics

    Institute of Scientific and Technical Information of China (English)

    Shao Xiao-Qiang; Chen Li; Zhang Shou

    2009-01-01

    This paper proposes two schemes for implementing three-qubit Toffoli gate with an atom (as target qubit) sent through a two-mode cavity (as control qubits). The first scheme is based on the large-detuning atom-cavity field interaction and the second scheme is based on the resonant atom-field interaction. Both the situations with and without cavity decay and atomic spontaneous emission are considered. The advantages and the experimental feasibility of these two schemes are discussed.

  11. Fluid phase thermodynamics : I) nucleate pool boiling of oxygen under magnetically enhanced gravity and II) superconducting cavity resonators for high-stability frequency references and precision density measurements of helium-4 gas

    Science.gov (United States)

    Corcovilos, Theodore Allen

    Although fluids are typically the first systems studied in undergraduate thermodynamics classes, we still have only a rudimentary phenomenological understanding of these systems outside of the classical and equilibrium regimes. Two experiments will be presented. First, we present progress on precise measurements of helium-4 gas at low temperatures (1 K-5 K). We study helium because at low densities it is an approximately ideal gas but at high densities the thermodynamic properties can be predicted by numerical solutions of Schroedinger's equation. By utilizing the high resolution and stability in frequency of a superconducting microwave cavity resonator we can measure the dielectric constant of helium-4 to parts in 109, corresponding to an equivalent resolution in density. These data will be used to calculate the virial coefficients of the helium gas so that we may compare with numerical predictions from the literature. Additionally, our data may allow us to measure Boltzmann's constant to parts in 108, a factor of 100 improvement over previous measurements. This work contains a description of the nearly-completed apparatus and the methods of operation and data analysis for this experiment. Data will be taken by future researchers.The second experiment discussed is a study of nucleate pool boiling. To date, no adequate quantitative model exists of this everyday phenomenon. In our experiment, we vary one parameter inaccessible to most researchers, gravity, by applying a magnetic force to our test fluid, oxygen. Using this technique, we may apply effective gravities of 0-80 times Earth's gravitational acceleration (g). In this work we present heat transfer data for the boiling of oxygen at one atmosphere ambient pressure for effective gravity values between 1g and 16g . Our data describe two relationships between applied heat flux and temperature differential: at low heat flux the system obeys a power law and at high heat flux the behavior is linear. We find that the

  12. 1.3μm GaInNAs 量子阱RCE光探测器%1.3μm GaInNAs/GaAs QUANTUM WELL RESONANT CAVITY ENHANCED PHOTODETECTOR

    Institute of Scientific and Technical Information of China (English)

    张瑞康; 钟源; 徐应强; 张纬; 黄永清; 任晓敏; 潘钟; 林耀望

    2002-01-01

    采用配有dc-N plasma N源的分子束外延(MBE)技术在GaAs衬底上生长制作了工作波长为1,3μm的GaInNAs量子阱RCE探测器.采用传输矩阵法对器件结构进行优化.吸收区由三个GaInNAs量子阱构成,并用湿法刻蚀和聚酰亚胺对器件进行隔离.在零偏压下,器件最大的量子效率为12%,半峰值全宽(FWHM)为5.8nm,3dB带宽为30MHz,暗电流为2×10-11A.通过对MBE生长条件和器件结构的优化,将进一步提高该器件的性能.%A 1.3μm GaInNAs resonant cavity enhanced (RCE) photodetector (PD) has been grown by molecular beam epitaxy(MBE) monolithically on (100) GaAs substrate using a home-made ion-removed dc-plasma cell as nitrogen source.A transfer matrix method was used to optimize the device structure.The absorption region is composed of three GaInNAs quantum wells separated by GaAs layers.Devices were isolated by etching 130μm-diameter mesas and filling polyamide into grooves.The maximal quantum efficiency of the device is about 12% at 1.293μm.Full width at half maximum (FWHM) is 5.8nm and 3dB bandwidth is 304MHz.Dark current is 2×10-11A at zero bias voltage.Further improvement of the performance of the RCE PD can be obtained by optimizing of the structure design and MBE growth conditions.

  13. Development of rebunching cavities at IAP

    CERN Document Server

    Welsch, C P; Schempp, A

    2000-01-01

    A focus of work at IAP has been the development and optimization of spiral loaded cavities since the 1970s [A. Schempp et al, NIM 135, 409 (1976)]. These cavities feature a high efficiency, a compact design and a big variety of possible fields of application. They find use both as bunchers and post accelerators to vary the final energy of the beam. In comparison to other available designs, the advantage of these structures lies in their small size. Furthermore they can easily be tuned to the required resonance frequency by varying the length of the spiral. Due to the small size of the cavities the required budget can also be kept low. Here, two slightly different types of spiral loaded cavities, which were built for the REX-ISOLDE project at CERN and the intensity upgrade program at GSI are being discussed.

  14. Cavity loss induced generation of W states

    Institute of Scientific and Technical Information of China (English)

    Wu Huai-Zhi; Yang Zhen-Biao; Su Wan-Jun; Zhong Zhi-Rong; Zheng Shi-Biao

    2008-01-01

    The existence of decoherence-free subspace (DFS) has been discussed widely.In this paper,we propose an alternative scheme for generating the four-atom W states by manipulating DF qubits.The atoms are divided into two pairs and trapped in two separate optical cavities.Manipulation of atoms within DFS may generate a two-atom maximally entangled state in an individual cavity,which is a stable state.After driving the system out of DFS,the atoms will interact resonantly with the cavity field.The photons leaking from the cavities interfere at the beamsplitter,which destroys which-path information,and are finally detected by one of the detectors,leading to the generation of a W state.In addition,the numerical simulation indicates that the fidelity of the prepared state can,for a very wide parameter regime,be very close to unity.

  15. Preparation of entangled W state via resonant interaction of V-type three-level atoms and two-mode cavity-field%利用V-型三能级原子与双模腔场的共振相互作用制备纠缠W态

    Institute of Scientific and Technical Information of China (English)

    胡明亮; 田东平; 柳海

    2007-01-01

    提出了一种利用V-型三能级原子与双模腔场的共振相互作用制备多原子及多腔场纠缠W态的新方案,并用共生纠缠度研究了该模型中的纠缠演化和热纠缠现象.%A new scheme for the preparation of multi-atom and nulti-cavity entangled W state via resonant interaction of V-type three-level atoms and two-mode cavity- field is proposed. Also the time evolution and the thermal entanglement of this model will be studied by the concept of concurrence in this paper.

  16. Dawn of Cavity Spintronics

    OpenAIRE

    Hu, Can-Ming

    2015-01-01

    Merging the progress of spintronics with the advancement in cavity quantum electrodynamics and cavity polaritons, a new field of Cavity Spintronics is forming, which connects some of the most exciting modern physics, such as quantum information and quantum optics, with one of the oldest science on the earth, the magnetism.

  17. Coherently Opening a High-Q Cavity

    Science.gov (United States)

    Tufarelli, Tommaso; Ferraro, Alessandro; Serafini, Alessio; Bose, Sougato; Kim, M. S.

    2014-04-01

    We propose a general framework to effectively "open" a high-Q resonator, that is, to release the quantum state initially prepared in it in the form of a traveling electromagnetic wave. This is achieved by employing a mediating mode that scatters coherently the radiation from the resonator into a one-dimensional continuum of modes such as a waveguide. The same mechanism may be used to "feed" a desired quantum field to an initially empty cavity. Switching between an open and "closed" resonator may then be obtained by controlling either the detuning of the scatterer or the amount of time it spends in the resonator. First, we introduce the model in its general form, identifying (i) the traveling mode that optimally retains the full quantum information of the resonator field and (ii) a suitable figure of merit that we study analytically in terms of the system parameters. Then, we discuss two feasible implementations based on ensembles of two-level atoms interacting with cavity fields. In addition, we discuss how to integrate traditional cavity QED in our proposal using three-level atoms.

  18. Beam cavity interaction

    CERN Document Server

    Gamp, A

    2011-01-01

    We begin by giving a description of the rf generator-cavity-beam coupled system in terms of basic quantities. Taking beam loading and cavity detuning into account, expressions for the cavity impedance as seen by the generator and as seen by the beam are derived. Subsequently methods of beam-loading compensation by cavity detuning, rf feedback, and feed-forward are described. Examples of digital rf phase and amplitude control for the special case of superconducting cavities are also given. Finally, a dedicated phase loop for damping synchrotron oscillations is discussed.

  19. Supersonic flows over cavities

    Institute of Scientific and Technical Information of China (English)

    Tianwen FANG; Meng DING; Jin ZHOU

    2008-01-01

    The characteristics of supersonic cold flows over cavities were investigated experimentally and numer-ically, and the effects of cavities of different sizes on super-sonic flow field were analyzed. The results indicate that the ratio of length to depth L/D within the range of 5-9 has little relevance to integral structures of cavity flow. The bevel angle of the rear wall does not alter the overall structure of the cavity flow within the range of 30°-60°, but it can exert obvious effect on the evolvement of shear layer and vortexes in cavities.

  20. Analytic Solution of the Electromagnetic Eigenvalues Problem in a Cylindrical Resonator

    CERN Document Server

    Checchin, Mattia

    2016-01-01

    Resonant accelerating cavities are key components in modern particles accelerating facilities. These take advantage of electromagnetic fields resonating at microwave frequencies to accelerate charged particles. Particles gain finite energy at each passage through a cavity if in phase with the resonating field, reaching energies even of the order of $TeV$ when a cascade of accelerating resonators are present. In order to understand how a resonant accelerating cavity transfers energy to charged particles, it is important to determine how the electromagnetic modes are exited into such resonators. In this paper we present a complete analytical calculation of the resonating fields for a simple cylindrical-shaped cavity.

  1. Cavity turnover and equilibrium cavity densities in a cottonwood bottomland

    Science.gov (United States)

    Sedgwick, James A.; Knopf, Fritz L.

    1992-01-01

    A fundamental factor regulating the numbers of secondary cavity nesting (SCN) birds is the number of extant cavities available for nesting. The number of available cavities may be thought of as being in an approximate equilibrium maintained by a very rough balance between recruitment and loss of cavities. Based on estimates of cavity recruitment and loss, we ascertained equilibrium cavity densities in a mature plains cottonwood (Populus sargentii) bottomland along the South Platte River in northeastern Colorado. Annual cavity recruitment, derived from density estimates of primary cavity nesting (PCN) birds and cavity excavation rates, was estimated to be 71-86 new cavities excavated/100 ha. Of 180 active cavities of 11 species of cavity-nesting birds found in 1985 and 1986, 83 were no longer usable by 1990, giving an average instantaneous rate of cavity loss of r = -0.230. From these values of cavity recruitment and cavity loss, equilibrium cavity density along the South Platte is 238-289 cavities/100 ha. This range of equilibrium cavity density is only slightly above the minimum of 205 cavities/100 ha required by SCN's and suggests that cavity availability may be limiting SCN densities along the South Platte River. We submit that snag management alone does not adequately address SCN habitat needs, and that cavity management, expressed in terms of cavity turnover and cavity densities, may be more useful.

  2. Cavity Optomechnics with 150nm-thick GaAs Membrane

    DEFF Research Database (Denmark)

    Usami, K.; Melholt Nielsen, B.; Naesby, A.

    2010-01-01

    -coupled to a Fabry-P´erot cavity formed between the membrane and a mirror (Finesse: 24) inside a vacuum chamber (10 7Torr), is used to lock the cavity length at the cavity resonant slope and to induce mechanical oscillations by modulating the intensity from the offset level for ring down measurements. We observe...

  3. Chaotic ray dynamics in an optical cavity with a beam splitter

    CERN Document Server

    Puentes, G; Woerdman, J P

    2003-01-01

    We investigate the ray dynamics in an optical cavity when a ray splitting mechanism is present. The cavity is a conventional two-mirror stable resonator and the ray splitting is achieved by inserting an optical beam splitter perpendicular to the cavity axis. Using Hamiltonian optics, we show that such a simple device presents a surprisingly rich chaotic ray dynamics.

  4. Cavity design for high-frequency axion dark matter detectors.

    Science.gov (United States)

    Stern, I; Chisholm, A A; Hoskins, J; Sikivie, P; Sullivan, N S; Tanner, D B; Carosi, G; van Bibber, K

    2015-12-01

    In an effort to extend the usefulness of microwave cavity detectors to higher axion masses, above ∼8 μeV (∼2 GHz), a numerical trade study of cavities was conducted to investigate the merit of using variable periodic post arrays and regulating vane designs for higher-frequency searches. The results show that both designs could be used to develop resonant cavities for high-mass axion searches. Multiple configurations of both methods obtained the scanning sensitivity equivalent to approximately 4 coherently coupled cavities with a single tuning rod.

  5. Multipacting Analysis of the Superconducting Parallel-bar Cavity

    Energy Technology Data Exchange (ETDEWEB)

    S.U. De Silva, J.R. Delayen,

    2011-03-01

    The superconducting parallel-bar cavity is a deflecting/crabbing cavity with attractive properties, compared to other conventional designs, that is being considered for a number of applications. Multipacting can be a limiting factor to the performance of in any superconducting structure. In the parallel-bar cavity the main contribution to the deflection is due to the transverse deflecting voltage, between the parallel bars, making the design potentially prone to multipacting. This paper presents the results of analytical calculations and numerical simulations of multipacting in the parallel-bar cavity with resonant voltage, impact energies and corresponding particle trajectories.

  6. Strong-Driving-Assisted Probabilistic State Preparation in Cavity QED

    Institute of Scientific and Technical Information of China (English)

    YANG Zhen-Biao

    2006-01-01

    An alternative scheme is proposed for preparing the superpositions of coherent states with controllable weighting factors along a straight line for a cavity field. The scheme is based on the interaction of a single-mode cavity field with a resonant two-level atom driven by a strong classical field. It is in contrast to the previous methods used in cavity QED of injecting a coherent state into a cavity via a microwave source. In the scheme, the interaction between the cavity mode and atoms is fully resonant, thus the required interaction time is greatly shortened. Moreover, the present scheme requires smaller numbers of operations. In view of decoherence, a reduction of interaction time and numbers of operations for the state preparation is very important for experimental implementation of quantum state engineering.

  7. The role of mode match in fiber cavities

    Energy Technology Data Exchange (ETDEWEB)

    Bick, A.; Staarmann, C.; Christoph, P. [ZOQ (Zentrum für Optische Quantentechnologien) Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany); Hellmig, O.; Heinze, J. [ILP (Institut für Laserphysik) Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany); Sengstock, K.; Becker, C., E-mail: cbecker@physnet.uni-hamburg.de [ZOQ (Zentrum für Optische Quantentechnologien) Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany); ILP (Institut für Laserphysik) Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany)

    2016-01-15

    We study and realize asymmetric fiber-based cavities with optimized mode match to achieve high reflectivity on resonance. This is especially important for mutually coupling two physical systems via light fields, e.g., in quantum hybrid systems. Our detailed theoretical and experimental analysis reveals that on resonance, the interference effect between the directly reflected non-modematched light and the light leaking back out of the cavity can lead to large unexpected losses due to the mode filtering of the incoupling fiber. Strong restrictions for the cavity design result out of this effect and we show that planar-concave cavities are clearly best suited. We validate our analytical model using numerical calculations and demonstrate an experimental realization of an asymmetric fiber Fabry-Pérot cavity with optimized parameters.

  8. The Role of Mode Match in Asymmetric Fiber Cavities

    CERN Document Server

    Bick, Andreas; Christoph, Philipp; Hellmig, Ortwin; Heinze, Jannes; Sengstock, Klaus; Becker, Christoph

    2015-01-01

    We study and realize asymmetric fiber-based cavities with optimized mode match to achieve high reflectivity on resonance. This is especially important for mutually coupling two physical systems via light fields, e.g. in quantum hybrid systems. Our detailed theoretical and experimental analysis reveals that on resonance the interference effect between the directly reflected non-modematched light and the light leaking back out of the cavity can lead to large unexpected losses due to the mode filtering of the incoupling fiber. Strong restrictions for the cavity design result out of this effect and we show that planar-concave cavities are clearly best suited. We validate our analytical model using numerical calculations and demonstrate an experimental realization of an asymmetric fiber Fabry-P\\'erot cavity with optimized parameters.

  9. Complex envelope control of pulsed accelerating fields in superconducting cavities

    CERN Document Server

    Czarski, T

    2010-01-01

    A digital control system for superconducting cavities of a linear accelerator is presented in this work. FPGA (Field Programmable Gate Arrays) based controller, managed by MATLAB, was developed to investigate a novel firmware implementation. The LLRF - Low Level Radio Frequency system for FLASH project in DESY is introduced. Essential modeling of a cavity resonator with signal and power analysis is considered as a key approach to the control methods. An electrical model is represented by the non-stationary state space equation for the complex envelope of the cavity voltage driven by the current generator and the beam loading. The electromechanical model of the superconducting cavity resonator including the Lorentz force detuning has been developed for a simulation purpose. The digital signal processing is proposed for the field vector detection. The field vector sum control is considered for multiple cavities driven by one klystron. An algebraic, complex domain model is proposed for the system analysis. The c...

  10. Coherent Dynamics of Quantum Dots in Photonic-Crystal Cavities

    DEFF Research Database (Denmark)

    Madsen, Kristian Høeg

    deviations. Similar measurements on a quantum dot in a photonic-crystal cavity sow a Rabi splitting on resonance, while time-resolved measurements prove that the system is in the weak coupling regime. Whle tuning the quantum dot through resonance of the high-Q mode we observe a strong and surprisingly...... Successfully model the decay rates with a microscopic model that allows us to for the first time extract the effective phonon density of states, which we can model with bulk phonons. Studies on a quantum dot detuned from a low-Q mode of a photonic-crystal cavity show a high collection efficiency at the first......In this thesis we have performed quantum-electrodynamics experiments on quantum dots embedded in photonic-crystal cavities. We perform a quantitative comparison of the decay dynamics and emission spectra of quantum dots embedded in a micropillar cavity and a photonic-crystal cavity. The light...

  11. Advanced configuration of gravitational-wave interferometer on the base of "sensitive mode" in "white-light cavity"

    OpenAIRE

    Karapetyan, G. G.

    2002-01-01

    A novel conception of "sensitive mode" (SM) is proposed to apply in gravitational-wave advanced interferometer configuration. The SM is resonant oscillation of electromagnetic field in "white-light cavity", where the resonance line is broadened without decreasing cavity quality. The frequency of the SM is greatly susceptible to the change of cavity length, and the SM is established in a cavity with time constant smaller than a conventional mode. Due to these advantages the sensitivity and ban...

  12. Mechanical stability study of capture cavity II at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    McGee, M.W.; Pischalnikov, Y.; /Fermilab

    2007-06-01

    Problematic resonant conditions at both 18 Hz and 180 Hz were encountered and identified early during the commissioning of Capture Cavity II (CC2) at Fermilab. CC2 consists of an external vacuum vessel and a superconducting high gradient (close to 25 MV/m) 9-cell 1.3 GHz niobium cavity, transported from DESY for use in the A0 Photoinjector at Fermilab. An ANSYS modal finite element analysis (FEA) was performed in order to isolate the source of the resonance and directed the effort towards stabilization. Using a fast piezoelectric tuner to excite (or shake) the cavity at different frequencies (from 5 Hz to 250 Hz) at a low-range sweep for analysis purposes. Both warm (300 K) and cold (1.8 K) accelerometer measurements at the cavity were taken as the resonant ''fix'' was applied. FEA results, cultural and technical noise investigation, and stabilization techniques are discussed.

  13. Observation of Transparency of Erbium-doped Silicon nitride in photonic crystal nanobeam cavities

    CERN Document Server

    Gong, Yiyang; Yerci, Selcuk; Li, Rui; Stevens, Martin J; Baek, Burm; Nam, Sae Woo; Negro, Luca Dal; Vuckovic, Jelena

    2010-01-01

    One-dimensional nanobeam photonic crystal cavities are fabricated in an Er-doped amorphous silicon nitride layer. Photoluminescence from the cavities around 1.54 um is studied at cryogenic and room temperatures at different optical pump powers. The resonators demonstrate Purcell enhanced absorption and emission rates, also confirmed by time-resolved measurements. Resonances exhibit linewidth narrowing with pump power, signifying absorption bleaching and the onset of stimulated emission in the material at both 5.5 K and room temperature. We estimate from the cavity linewidths that Er has been pumped to transparency at the cavity resonance wavelength.

  14. Niobium coaxial quarter-wave cavities for the New Delhi booster linac

    Energy Technology Data Exchange (ETDEWEB)

    Shepard, K.W. [Argonne National Lab., IL (United States); Roy, A.; Potukuchi, P.N. [Nuclear Science Centre, New Delhi (India)

    1993-07-01

    This paper reports the design and construction status of a prototype superconducting niobium accelerating structure consisting of a pair of quarter-wave coaxial-line cavities which are strongly coupled with a superconducting loop. Quarter-wave resonators are two-gap accelerating structures and are relatively short, so that a large number of independently-phased cavities is required for a linac. Strongly coupling several cavities can reduce the number of independently-phased elements, but at the cost of reducing the range of useful velocity acceptance for each element. Coupling two cavities splits the accelerating rf eigenmode into two resonant modes each of which covers a portion of the full velocity acceptance range of the original single cavity mode. Using both of these resonant modes makes feasible the use of coupled cavity pairs for a linac with little loss m velocity acceptance. Design details for the niobium cavity pair and the results of preliminary tests of multipacting behavior are discussed.

  15. Ultra-high Q sphere-like cavities for cascaded stimulated Brillouin lasing

    Science.gov (United States)

    Che, Kaijun; Zhang, Pan; Guo, Changlei; Tang, Deyu; Ren, Changyan; Xu, Huiying; Luo, Zhengqian; Cai, Zhiping

    2017-03-01

    High Q microsphere optical cavity is usually fabricated from a single mode fiber. Here, we propose a new method to fabricate sphere-like cavity by melting the tip of rotating quartz-rod with a CO2 laser. The cavities with diameter from 200 μm to 700 μm and resonant Q factors above 108 are obtained. Due to the rich resonances of the sphere-like cavity, up to 15-order cascaded stimulated Brillouin lasings(SBL) near 1.55 μm are observed in a cavity with a diameter of 760 μm by simply tuning the pump wavelength to a finely-selected resonance. We wish the ultra-high Q cavities with rich resonances and bulk rod mount can have practical applications in nonlinear optics and microwave photonics as an optical component.

  16. 0.5W CW single frequency blue at 486 nm via SHG with net conversion of 81.5% from the NIR using a 30mm PPMgO:SLT crystal in a resonant cavity

    Science.gov (United States)

    Khademian, Ali; Jadhav, Shilpa; Shiner, David

    2015-02-01

    A single frequency fiber Bragg grating (FBG) stabilized laser at 972 nm is coupled into a doubling ring cavity with an optical length of 138 mm, a 91% input coupler, a 30 mm long Brewster cut magnesium doped periodically poled lithium tantalate (PPMgO:SLT) crystal and a high reflector. The cavity buildup is 37 and loss is 0.63%. The cavity is monitored, controlled and locked with a single chip processor. With IR power of 572 mW in the input fiber, 466 mW blue output is obtained, giving 81.5% net efficiency. The blue and IR beams are separated by refraction at the crystal's Brewster surface with negligible loss and without the need for dichroic optics.

  17. Energy Levels of Coupled Plasmonic Cavities

    Institute of Scientific and Technical Information of China (English)

    Chuan-Pu Liu; Xin-Li Zhu; Jia-Sen Zhang; Jun Xu; Yamin Leprince-Wang; Da-Peng Yu

    2016-01-01

    We demonstrate the hybridization of the plasmonic modes in directly coupled whispering gallery cavities fabricated on silver films and present the mode patterns and energy levels using cathodoluminescence spectroscopy.Although the energy of the most antisymmetrically coupled modes is higher than that of the corresponding symmetrically coupled ones,the contrary cases happen for small quantum number modes.We attribute the phenomenon to the different surface plasmon polariton paths between the symmetrically and antisymmetrically coupled modes.These results provide an understanding of the resonant properties in coupled plasmonic cavities,which have potential applications in nanophotonic devices.

  18. Accelerating RF cavity of the Booster

    CERN Multimedia

    1983-01-01

    Each of the 4 PS Booster rings has a single accelerating cavity.It consists of 2 quarter-wave ferrite-loaded resonators. 2 figure-of-eight loops tune the frequency throughout the accelerating cycle, from 3 to 8 MHz (from 50 MeV at injection to the original Booster energy of 800 MeV, 2 GeV today). The cavities have a flat design, to fit the ring-to-ring distance of 36 cm, and are forced-air cooled. The 2 round objects in the front-compartments are the final-stage power-tetrodes. See also 8111095.

  19. Accelerating RF cavity of the Booster

    CERN Multimedia

    CERN PhotoLab

    1981-01-01

    Each of the 4 PS Booster rings has a single accelerating cavity. It consists of 2 quarter-wave ferrite-loaded resonators. There are 2 figure-of-eight loops on the ferrite loads for tuning the frequency throughout the acceleration cycle, from 3 to 8 MHz (from 50 MeV at injection to the original Booster energy of 800 MeV, 2 GeV today). The cavities have a flat design, to fit the ring-to-ring distance of 36 cm. The tube for forced-air cooling is visible in the left front. See also 8301084.

  20. Cavity Loss Induced Generation of Entangled Atoms

    CERN Document Server

    Plenio, M B; Beige, A; Knight, P L

    1999-01-01

    We discuss the generation of entangled states of two two-level atoms inside an optical resonator. When the cavity decay is continuously monitored, the absence of photon-counts is associated with the presence of an atomic entangled state. In addition to being conceptually simple, this scheme could be demonstrated with presently available technology. We describe how such a state is generated through conditional dynamics, using quantum jump methods, including both cavity damping and spontaneous emission decay, and evaluate the fidelity and relative entropy of entanglement of the generated state compared with the target entangled state.

  1. Open Microwave Cavity for use in a Purcell Enhancement Cooling Scheme

    CERN Document Server

    Evetts, N; Bizzotto, D; Longuevergne, D; Hardy, W N

    2016-01-01

    A microwave cavity is described which can be used to cool lepton plasmas for potential use in synthesis of antihydrogen. The cooling scheme is an incarnation of the Purcell Effect: when plasmas are coupled to a microwave cavity, the plasma cooling rate is resonantly enhanced through increased spontaneous emission of cyclotron radiation. The cavity forms a three electrode section of a Penning-Malmberg trap and has a bulged cylindrical geometry with open ends aligned with the magnetic trapping axis. This allows plasmas to be injected and removed from the cavity without the need for moving parts while maintaining high quality factors for resonant modes. The cavity includes unique surface preparations for adjusting the cavity quality factor and achieving anti-static shielding using thin layers of nichrome and colloidal graphite respectively. Geometric design considerations for a cavity with strong cooling power and low equilibrium plasma temperatures are discussed. Cavities of this weak-bulge design will be appli...

  2. LEP copper accelerating cavities

    CERN Multimedia

    Laurent Guiraud

    1999-01-01

    These copper cavities were used to generate the radio frequency electric field that was used to accelerate electrons and positrons around the 27-km Large Electron-Positron (LEP) collider at CERN, which ran from 1989 to 2000. The copper cavities were gradually replaced from 1996 with new superconducting cavities allowing the collision energy to rise from 90 GeV to 200 GeV by mid-1999.

  3. The first operation of 56 MHz SRF cavity in RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Q. [Brookhaven National Lab. (BNL), Upton, NY (United States); Belomestnykh, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ben-Zvi, I. [Brookhaven National Lab. (BNL), Upton, NY (United States); Blaskiewicz, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); DeSanto, L. [Brookhaven National Lab. (BNL), Upton, NY (United States); Goldberg, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Harvey, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Hayes, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); McIntyre, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Mernick, K. [Brookhaven National Lab. (BNL), Upton, NY (United States); Orfin, P. [Brookhaven National Lab. (BNL), Upton, NY (United States); Seberg, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Severino, F. [Brookhaven National Lab. (BNL), Upton, NY (United States); Smith, K. [Brookhaven National Lab. (BNL), Upton, NY (United States); Than, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Zaltsman, A. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-05-03

    A 56 MHz superconducting RF cavity has been designed, fabricated and installed in the Relativistic Heavy Ion Collider (RHIC). The cavity operates at 4.4 K with a “quiet helium source” to isolate the cavity from environmental acoustic noise. The cavity is a beam driven quarter wave resonator. It is detuned and damped during injection and acceleration cycles and is brought to operation only at store energy. For a first test operation, the cavity voltage was stabilized at 300 kV with full beam current. Within both Au + Au and asymmetrical Au + He3 collisions, luminosity improvement was detected from direct measurement, and the hourglass effect was reduced. One higher order mode (HOM) coupler was installed on the cavity. We report in this paper on our measurement of a broadband HOM spectrum excited by the Au beam.

  4. Scheme for implementing the Deutsch-Jozsa algorithm in cavity QED

    Science.gov (United States)

    Zheng, Shi-Biao

    2004-09-01

    We propose a scheme for realizing the Deutsch-Jozsa algorithm in cavity QED. The scheme is based on the resonant interaction of atoms with a cavity mode. The required experimental techniques are within the scope of what can be obtained in the microwave cavity QED setup. The experimental implementation of the scheme would be an important step toward more complex quantum computation in cavity QED.

  5. All-solid-state ultraviolet laser based on frequency doubling in an external ring cavity

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    An all-solid-state ultraviolet laser based on frequency doubling in an external ring cavity with low input pump power is reported. Both second harmonic generation (SHG) and fourth harmonic generation (FHG) occurred in an external threemirrors ring cavity. The need for impedance matching of this cavity to the input radiation was eliminated and the cavity adaptation was simplified, because the mirrors were not highly reflecting at 1064 nm and the cavity resonates only at 532 nm. Experiment results demonstrate that the conversion efficiency of this external cavity is higher than that of the singlepass condition.

  6. Demonstration of superconducting micromachined cavities

    Energy Technology Data Exchange (ETDEWEB)

    Brecht, T., E-mail: teresa.brecht@yale.edu; Reagor, M.; Chu, Y.; Pfaff, W.; Wang, C.; Frunzio, L.; Devoret, M. H.; Schoelkopf, R. J. [Department of Applied Physics, Yale University, New Haven, Connecticut 06511 (United States)

    2015-11-09

    Superconducting enclosures will be key components of scalable quantum computing devices based on circuit quantum electrodynamics. Within a densely integrated device, they can protect qubits from noise and serve as quantum memory units. Whether constructed by machining bulk pieces of metal or microfabricating wafers, 3D enclosures are typically assembled from two or more parts. The resulting seams potentially dissipate crossing currents and limit performance. In this letter, we present measured quality factors of superconducting cavity resonators of several materials, dimensions, and seam locations. We observe that superconducting indium can be a low-loss RF conductor and form low-loss seams. Leveraging this, we create a superconducting micromachined resonator with indium that has a quality factor of two million, despite a greatly reduced mode volume. Inter-layer coupling to this type of resonator is achieved by an aperture located under a planar transmission line. The described techniques demonstrate a proof-of-principle for multilayer microwave integrated quantum circuits for scalable quantum computing.

  7. SPS accelerating cavity

    CERN Multimedia

    1980-01-01

    One of the SPS acceleration cavities (200 MHz, travelling wave structure). On the ceiling one sees the coaxial transmission line which feeds the power from the amplifier, located in a surface building above, to the upstream end of the cavity. See 7603195 for more details, 7411032 for the travelling wave structure, and also 8104138, 8302397.

  8. Superconducting cavities for LEP

    CERN Multimedia

    1983-01-01

    Above: a 350 MHz superconducting accelerating cavity in niobium of the type envisaged for accelerating electrons and positrons in later phases of LEP. Below: a small 1 GHz cavity used for investigating the surface problems of superconducting niobium. Albert Insomby stays on the right. See Annual Report 1983 p. 51.

  9. SPS accelerating cavity

    CERN Multimedia

    CERN PhotoLab

    1981-01-01

    One of the SPS accelerating cavities (200 MHz, travelling wave structure). The power that is fed into the upstream end of the cavity is extracted at the downstream end and sent into a dump load. See 7603195 for more details, 7411032 for the travelling wave structure, and also 8011289, 8302397.

  10. Improving nanocavity switching using Fano resonances in photonic crystal structures

    DEFF Research Database (Denmark)

    Heuck, Mikkel; Kristensen, Philip Trøst; Elesin, Yuriy;

    2013-01-01

    We present a simple design for achieving Fano resonances in photonic crystal coupled waveguide-cavity structures. A coupled mode theory analysis shows an order of magnitude reduction in switching energy compared to conventional Lorentz resonances.......We present a simple design for achieving Fano resonances in photonic crystal coupled waveguide-cavity structures. A coupled mode theory analysis shows an order of magnitude reduction in switching energy compared to conventional Lorentz resonances....

  11. A coupled microwave-cavity system in the Rydberg-atom cavity detector for dark matter axions

    CERN Document Server

    Tada, M; Shibata, M; Kominato, K; Ogawa, I; Funahashi, H; Yamamoto, K; Matsuki, S

    2001-01-01

    A coupled microwave-cavity system of cylindrical TM$_{010}$ single-mode has been developed to search for dark matter axions around 10 $\\mu {\\rm eV}$(2.4 GHz) with the Rydberg-atom cavity detector at 10 mK range temperature. One component of the coupled cavity (conversion cavity) made of oxygen-free high-conductivity copper is used to convert an axion into a single photon with the Primakoff process in the strong magnetic field, while the other component (detection cavity) made of Nb is utilized to detect the converted photons with Rydberg atoms passed through it without magnetic field. Top of the detection cavity is attached to the bottom flange of the mixing chamber of a dilution refrigerator, thus the whole cavity is cooled down to 10 mK range to reduce the background thermal blackbody-photons in the cavity. The cavity resonant frequency is tunable over $\\sim$ 15% by moving dielectric rods inserted independently into each part of the cavities along the cylindrical axis. In order to reduce the heat load from ...

  12. High Finesse Fiber Fabry-Perot Cavities: Stabilization and Mode Matching Analysis

    CERN Document Server

    Gallego, Jose; Alavi, Seyed Khalil; Alt, Wolfgang; Martinez-Dorantes, Miguel; Meschede, Dieter; Ratschbacher, Lothar

    2015-01-01

    Fiber Fabry-Perot cavities, formed by micro-machined mirrors on the end-facets of optical fibers, are used in an increasing number of technical and scientific applications, where they typically require precise stabilization of their optical resonances. Here, we study two different approaches to construct fiber Fabry-Perot resonators and stabilize their length for experiments in cavity quantum electrodynamics with neutral atoms. A piezo-mechanically actuated cavity with feedback based on the Pound-Drever-Hall locking technique is compared to a novel rigid cavity design that makes use of the high passive stability of a monolithic cavity spacer and employs thermal self-locking and external temperature tuning. Furthermore, we present a general analysis of the mode matching problem in fiber Fabry-Perot cavities, which explains the asymmetry in their reflective line shapes and has important implications for the optimal alignment of the fiber resonators. Finally, we discuss the issue of fiber-generated background ph...

  13. Leaky Modes of Dielectric Cavities

    CERN Document Server

    Mansuripur, Masud; Jakobsen, Per

    2016-01-01

    In the absence of external excitation, light trapped within a dielectric medium generally decays by leaking out (and also by getting absorbed within the medium). We analyze the leaky modes of a parallel-plate slab, a solid glass sphere, and a solid glass cylinder, by examining those solutions of Maxwell's equations (for dispersive as well as non-dispersive media) which admit of a complex-valued oscillation frequency. Under certain circumstances, these leaky modes constitute a complete set into which an arbitrary distribution of the electromagnetic field residing inside a dielectric body can be expanded. We provide completeness proofs, and also present results of numerical calculations that illustrate the relationship between the leaky modes and the resonances of dielectric cavities formed by a simple parallel-plate slab, a glass sphere, and a glass cylinder.

  14. SPS RF Accelerating Cavity

    CERN Multimedia

    1979-01-01

    This picture shows one of the 2 new cavities installed in 1978-1979. The main RF-system of the SPS comprises four cavities: two of 20 m length and two of 16.5 m length. They are all installed in one long straight section (LSS 3). These cavities are of the travelling-wave type operating at a centre frequency of 200.2 MHz. They are wideband, filling time about 700 ns and untuned. The power amplifiers, using tetrodes are installed in a surface building 200 m from the cavities. Initially only two cavities were installed, a third cavity was installed in 1978 and a forth one in 1979. The number of power amplifiers was also increased: to the first 2 MW plant a second 2 MW plant was added and by end 1979 there were 8 500 kW units combined in pairs to feed each of the 4 cavities with up to about 1 MW RF power, resulting in a total accelerating voltage of about 8 MV. See also 7412016X, 7412017X, 7411048X

  15. SPS RF Cavity

    CERN Multimedia

    1975-01-01

    The picture shows one of the two initially installed cavities. The main RF-system of the SPS comprises four cavities: two of 20 m length and two of 16.5 m length. They are all installed in one long straight section (LSS 3). These cavities are of the travelling-wave type operating at a centre frequency of 200.2 MHz. They are wideband, filling time about 700 ns and untuned. The power amplifiers, using tetrodes are installed in a surface building 200 m from the cavities. Initially only two cavities were installed, a third cavity was installed in 1978 and a forth one in 1979. The number of power amplifiers was also gradually increased: by end 1980 there were 8 500 kW units combined in pairs to feed each of the 4 cavities with up to about 1 MW RF power, resulting in a total accelerating voltage of about 8 MV. See also 7412017X, 7411048X, 7505074.

  16. Long Wave Infrared Cavity Enhanced Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Taubman, Matthew S.; Scott, David C.; Cannon, Bret D.; Myers, Tanya L.; Bonebrake, Christopher A.; Aker, Pam M.; Wojcik, Michael D.; Munley, John T.; Nguyen, Vinh T.; Schultz, John F.

    2004-10-01

    The principal goal of Pacific Northwest National Laboratory's (PNNL's) long wave infrared (LWIR) cavity enhanced sensor (CES) project is to explore ultra-sensitive spectroscopic techniques and apply them to the development of LWIR chemical sensors needed for detecting weapons proliferation. This includes detecting not only the weapons of mass destruction (WMDs) themselves, but also signatures of their production and/or detonation. The LWIR CES project is concerned exclusively with developing point sensors; other portions of PNNL's IR Sensors program address stand off detection. PNNL's LWIR CES research is distinguished from that done by others by the use quantum cascade lasers (QCLs) as the light source. QCLs are novel devices, and a significant fraction of our research has been devoted to developing the procedures and hardware required to implement them most effectively for chemical sensing. This report details the progress we have made on our LWIR CES sensor development. During FY02, PNNL investigated three LWIR CES implementations beginning with the easiest to implement, direct cavity-enhanced detection (simple CES), including a technique of intermediate difficulty, cavity-dithered phase-sensitive detection (FM recovery CES) through to the most complex technique, that of resonant sideband cavity-enhanced detection also known as noise-immune cavity-enhanced optical heterodyne molecular spectroscopy, or NICE-OHMS.

  17. Plasmonic band gap cavities on biharmonic gratings

    Science.gov (United States)

    Kocabas, Askin; Seckin Senlik, S.; Aydinli, Atilla

    2008-05-01

    In this paper, we have experimentally demonstrated the formation of plasmonic band gap cavities in infrared and visible wavelength range. The cavity structure is based on a biharmonic metallic grating with selective high dielectric loading. A uniform metallic grating structure enables strong surface plasmon polariton (SPP) excitation and a superimposed second harmonic component forms a band gap for the propagating SPPs. We show that a high dielectric superstructure can dramatically perturb the optical properties of SPPs and enables the control of the plasmonic band gap structure. Selective patterning of the high index superstructure results in an index contrast in and outside the patterned region that forms a cavity. This allows us to excite the SPPs that localize inside the cavity at specific wavelengths, satisfying the cavity resonance condition. Experimentally, we observe the formation of a localized state in the band gap and measure the dispersion diagram. Quality factors as high as 37 have been observed in the infrared wavelength. The simplicity of the fabrication and the method of testing make this approach attractive for applications requiring localization of propagating SPPs.

  18. Dynamical Casimir Effect in a Leaky Cavity at Finite Temperature

    CERN Document Server

    Schaller, G; Plunien, G; Soff, G

    2002-01-01

    The phenomenon of particle creation within an almost resonantly vibrating cavity with losses is investigated for the example of a massless scalar field at finite temperature. A leaky cavity is designed via the insertion of a dispersive mirror into a larger ideal cavity (the reservoir). In the case of parametric resonance the rotating wave approximation allows for the construction of an effective Hamiltonian. The number of produced particles is then calculated using response theory as well as a non-perturbative approach. In addition we study the associated master equation and briefly discuss the effects of detuning. The exponential growth of the particle numbers and the strong enhancement at finite temperatures found earlier for ideal cavities turn out to be essentially preserved. The relevance of the results for experimental tests of quantum radiation via the dynamical Casimir effect is addressed. Furthermore the generalization to the electromagnetic field is outlined.

  19. Mechanically Amplified Piezoelectric Tunable 3D Microwave Superconducting Cavity

    CERN Document Server

    Carvalho, N C; Tobar, M E

    2016-01-01

    In the context of hybrid quantum systems, there is a demand for superconducting tunable devices able to operate in the single-photon regime. In this work, we developed a 3D microwave reentrant cavity with such characteristics ready to provide a very fine-tuning of a high-Q resonant mode over a large dynamic range. This system has an electronic tuning mechanism based on a mechanically amplified piezoelectric actuator, which can set the cavity resonance with a large dynamic range of order 1 GHz at 10 mK. At elevated microwave power, nonlinear thermal e effects were observed to destroy the superconductivity of the cavity due to the large electric fields generated in the small gap of the reentrant cavity.

  20. Tuned optical cavity magnetometer

    Science.gov (United States)

    Okandan, Murat; Schwindt, Peter

    2010-11-02

    An atomic magnetometer is disclosed which utilizes an optical cavity formed from a grating and a mirror, with a vapor cell containing an alkali metal vapor located inside the optical cavity. Lasers are used to magnetically polarize the alkali metal vapor and to probe the vapor and generate a diffracted laser beam which can be used to sense a magnetic field. Electrostatic actuators can be used in the magnetometer for positioning of the mirror, or for modulation thereof. Another optical cavity can also be formed from the mirror and a second grating for sensing, adjusting, or stabilizing the position of the mirror.

  1. Tuning Leaky Nanocavity Resonances - Perturbation Treatment

    CERN Document Server

    Shlafman, Michael; Salzman, Joseph

    2010-01-01

    Adiabatic frequency tuning of finite-lifetime-nanocavity electromagnetic modes affects also their quality-factor (Q). Perturbative Q change resulting from (real) frequency tuning, is a controllable parameter. Here, the influence of dielectric constant modulation (DCM) on cavity resonances is presented, by first order perturbation analysis for a 3D cavity with radiation losses. Semi-analytical expressions for DCM induced cavity mode frequency and Q changes are derived. The obtained results are in good agreement with numerical calculations.

  2. Photonic Crystal Cavities in Cubic Polytype Silicon Carbide Films

    CERN Document Server

    Radulaski, Marina; Buckley, Sonia; Rundquist, Armand; Provine, J; Alassaad, Kassem; Ferro, Gabriel; Vučković, Jelena

    2013-01-01

    We present the design, fabrication, and characterization of high quality factor and small mode volume planar photonic crystal cavities from cubic (3C) thin films (thickness ~ 200 nm) of silicon carbide (SiC) grown epitaxially on a silicon substrate. We demonstrate cavity resonances across the telecommunications band, with wavelengths from 1250 - 1600 nm. Finally, we discuss possible applications in nonlinear optics, optical interconnects, and quantum information science.

  3. A high resolution cavity BPM for the CLIC Test Facility

    CERN Document Server

    Chritin, N; Soby, L; Lunin, A; Solyak, N; Wendt, M; Yakovlev, V

    2012-01-01

    In frame of the development of a high resolution BPM system for the CLIC Main Linac we present the design of a cavity BPM prototype. It consists of a waveguide loaded dipole mode resonator and a monopole mode reference cavity, both operating at 15 GHz, to be compatible with the bunch frequencies at the CLIC Test Facility. Requirements, design concept, numerical analysis, and practical considerations are discussed.

  4. Generation of a Dark Hollow Beam inside a Cavity

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lei; LU Xuan-Hui; CHEN Xu-Min; HE Sai-Ling

    2004-01-01

    @@ A new method is introduced to generate a hollow beam inside a cavity. Using a matrix eigenvalue method, the laser resonator with optical diffraction elements is theoretically analysed and simulated. The hollow beam can be obtained theoretically by controlling the parameters of the diffraction functions. After designed the diffraction components in the cavity, a hollow beam of good quality is realized experimentally using a YAG solid state laser.

  5. High-Q cavity-induced synchronization in oscillator arrays

    DEFF Research Database (Denmark)

    Filatrella, Giovanni; Pedersen, Niels Falsig; Wiesenfeld, Kurt

    2000-01-01

    A model for a large number of Josephson junctions coupled to a cavity is presented. The system displays synchronization behavior very similar to that reported in recent experiments [P. Barbara ct al., Phys. Rev. Lett. 82, 1963 (1999)]. The essential dynamical mechanism responsible for coherence...... should be generic in nonlinear oscillator systems where the interactions are mediated by a highly resonant cavity, in analogy with gas lasers....

  6. Local tuning of photonic crystal cavities using chalcogenide glasses

    CERN Document Server

    Faraon, Andrei; Bulla, Douglas; Luther-Davies, Barry; Eggleton, Benjamin J; Stoltz, Nick; Petroff, Pierre; Vuckovic, Jelena

    2007-01-01

    We demonstrate a method to locally change the refractive index in planar optical devices by photodarkening of a thin chalcogenide glass layer deposited on top of the device. The method is used to tune the resonance of GaAs-based photonic crystal cavities by up to 3 nm at 940 nm, with only 5% deterioration in cavity quality factor. The method has broad applications for postproduction tuning of photonic devices.

  7. A high resolution cavity BPM for the CLIC Test Facility

    Energy Technology Data Exchange (ETDEWEB)

    Chritin, N.; Schmickler, H.; Soby, L.; /CERN; Lunin, A.; Solyak, N.; Wendt, M.; Yakovlev, V.; /Fermilab

    2010-08-01

    In frame of the development of a high resolution BPM system for the CLIC Main Linac we present the design of a cavity BPM prototype. It consists of a waveguide loaded dipole mode resonator and a monopole mode reference cavity, both operating at 15 GHz, to be compatible with the bunch frequencies at the CLIC Test Facility. Requirements, design concept, numerical analysis, and practical considerations are discussed.

  8. Low-dissipation cavity optomechanics in single-crystal diamond

    CERN Document Server

    Mitchell, Matthew; Lake, David P; Barclay, Paul E

    2015-01-01

    Single-crystal diamond cavity optomechanical devices are a promising example of a hybrid quantum system: by coupling mechanical resonances to both light and electron spins, they can enable new ways for photons to control solid state qubits. However, creating devices from high quality bulk diamond chips is challenging. Here we demonstrate single-crystal diamond cavity optomechanical devices that can enable photon-phonon-spin coupling. Cavity optomechanical coupling to $2\\,\\text{GHz}$ frequency ($f_\\text{m}$) mechanical resonances is observed. In room temperature ambient conditions, the resonances have a record combination of low dissipation ($Q_\\text{m} > 9000$) and high frequency, with $Q_\\text{m}\\cdot f_\\text{m} \\sim 1.9\\times10^{13}$ sufficient for room temperature single phonon coherence. The system is nearly sideband resolved, and radiation pressure is used to excite $\\sim 31\\,\\text{pm}$ amplitude mechanical self-oscillations that can drive diamond color centre electron spin transitions.

  9. Resonance fluorescence of a cold atom in a high-finesse resonator

    CERN Document Server

    Bienert, M; Torres, J M; Zippilli, S; Bienert, Marc; Morigi, Giovanna; Zippilli, Stefano

    2007-01-01

    We study the spectra of emission of a system composed by an atom, tightly confined inside a high-finesse resonator, when the atom is driven by a laser and is at steady state of the cooling dynamics induced by laser and cavity field. In general, the spectrum of resonance fluorescence and the spectrum at the cavity output contain complementary information about the dynamics undergone by the system. In certain parameter regimes, quantum interference effects between the scattering processes induced by cavity and laser field lead to the selective suppression of features of the resonance fluorescence spectrum, which are otherwise visible in the spectrum of laser-cooled atoms in free space.

  10. Cooperative effects of two optical dipole antennas coupled to plasmonic Fabry-Pérot cavity.

    Science.gov (United States)

    Yang, Zhong-Jian; Wang, Qu-Quan; Lin, Hai-Qing

    2012-09-07

    We investigate the cooperative effects of two optical dipole antennas that are coupled to a finite Au nanowire acting as plasmonic Fabry-Pérot (F-P) cavity. The coherent coupling between one single antenna and the F-P cavity can result in Fano resonance, and the coupling strength is antenna position dependent. For two antennas coupled to the F-P cavity, constructive or destructive interference between antennas could be achieved by adjusting their positions along the F-P cavity. Consequently, the Fano resonance will become stronger or weaker correspondingly.

  11. accelerating cavity from LEP

    CERN Multimedia

    This is an accelerating cavity from LEP, with a layer of niobium on the inside. Operating at 4.2 degrees above absolute zero, the niobium is superconducting and carries an accelerating field of 6 million volts per metre with negligible losses. Each cavity has a surface of 6 m2. The niobium layer is only 1.2 microns thick, ten times thinner than a hair. Such a large area had never been coated to such a high accuracy. A speck of dust could ruin the performance of the whole cavity so the work had to be done in an extremely clean environment. These challenging requirements pushed European industry to new achievements. 256 of these cavities are now used in LEP to double the energy of the particle beams.

  12. SPS accelerating cavity

    CERN Multimedia

    1976-01-01

    The SPS started up with 2 accelerating cavities (each consisting of 5 tank sections) in LSS3. They have a 200 MHz travelling wave structure (see 7411032 and 7802190) and 750 kW of power is fed to each of the cavities from a 1 MW tetrode power amplifier, located in a surface building above, via a coaxial transmission line. Clemens Zettler, builder of the SPS RF system, is standing at the side of one of the cavities. In 1978 and 1979 another 2 cavities were added and entered service in 1980. These were part of the intensity improvement programme and served well for the new role of the SPS as proton-antiproton collider. See also 7411032, 8011289, 8104138, 8302397.

  13. Apparatus and method for plasma processing of SRF cavities

    CERN Document Server

    Upadhyay, J; Peshl, J; Bašović, M; Popović, S; Valente-Feliciano, A -M; Phillips, L; Vuškovića, L

    2015-01-01

    An apparatus and a method are described for plasma etching of the inner surface of superconducting radio frequency (SRF) cavities. Accelerator SRF cavities are formed into a variable-diameter cylindrical structure made of bulk niobium, for resonant generation of the particle accelerating field. The etch rate non-uniformity due to depletion of the radicals has been overcome by the simultaneous movement of the gas flow inlet and the inner electrode. An effective shape of the inner electrode to reduce the plasma asymmetry for the coaxial cylindrical rf plasma reactor is determined and implemented in the cavity processing method. The processing was accomplished by moving axially the inner electrode and the gas flow inlet in a step-wise way to establish segmented plasma columns. The test structure was a pillbox cavity made of steel of similar dimension to the standard SRF cavity. This was adopted to experimentally verify the plasma surface reaction on cylindrical structures with variable diameter using the segment...

  14. Benchmarking Microwave Cavity Dark Matter Searches using a Radioactive Source

    CERN Multimedia

    Caspers, F

    2014-01-01

    A radioactive source is proposed as a calibration device to verify the sensitivity of a microwave dark matter search experiment. The interaction of e.g., electrons travelling in an arbitrary direction and velocity through an electromagnetically “empty” microwave cavity can be calculated numerically. We give an estimation of the energy deposited by a charged particle into a particular mode. Numerical examples are given for beta emitters and two particular cases: interaction with a field free cavity and interaction with a cavity which already contains an electromagnetic field. Each particle delivers a certain amount of energy related to the modal R/Q value of the cavity. The transferred energy is a function of the particles trajectory and its velocity. It results in a resonant response of the cavity, which can be observed using a sensitive microwave receiver, provided that the deposited energy is significantly above the single photon threshold.

  15. Hybrid vertical cavity laser

    DEFF Research Database (Denmark)

    Chung, Il-Sug; Mørk, Jesper

    2010-01-01

    A new hybrid vertical cavity laser structure for silicon photonics is suggested and numerically investigated. It incorporates a silicon subwavelength grating as a mirror and a lateral output coupler to a silicon ridge waveguide.......A new hybrid vertical cavity laser structure for silicon photonics is suggested and numerically investigated. It incorporates a silicon subwavelength grating as a mirror and a lateral output coupler to a silicon ridge waveguide....

  16. Observation of Three Mode Parametric Interactions in Long Optical Cavities

    CERN Document Server

    Zhao, C; Fan, Y; Slagmolen, S Gras B J J; Miao, H; Blair, P Barriga D G; Hosken, D J; Brooks, A F; Veitch, P J; Mudge, D; Munch, J

    2008-01-01

    We report the first observation of three-mode opto-acoustic parametric interactions of the type predicted to cause parametric instabilities in an 80 m long, high optical power cavity that uses suspended sapphire mirrors. Resonant interaction occurs between two distinct optical modes and an acoustic mode of one mirror when the difference in frequency between the two optical cavity modes is close to the frequency of the acoustic mode. Experimental results validate the theory of parametric instability in high power optical cavities.

  17. Design of the Advanced Virgo non-degenerate recycling cavities

    Energy Technology Data Exchange (ETDEWEB)

    Granata, M; Barsuglia, M [Laboratoire Astroparticule et Cosmologie (APC) 10 rue Alice Domon et Leonie Duquet, 75013 Paris (France); Flaminio, R [Laboratoire des Materiaux Avances (LMA), IN2P3/CNRS F-69622 Villeurbanne, Lyon (France); Freise, A [School of Physics and Astronomy, University of Birmingham Birmingham, B15 2TT (United Kingdom); Hild, S [Institute for Gravitational Research, Department of Physics and Astronomy University of Glasgow, Glasgow, G12 8QQ (United Kingdom); Marque, J, E-mail: granata@apc.univ-paris7.f [European Gravitational Observatory (EGO) I-56021 Cascina (Italy)

    2010-05-01

    Advanced Virgo is the project to upgrade the interferometric gravitational wave detector Virgo, and it foresees the implementation of power and signal non-degenerate recycling cavities. Such cavities suppress the build-up of high order modes of the resonating sidebands, with some advantage for the commissioning of the detector and the build-up of the gravitational signal. Here we present the baseline design of the Advanced Virgo non-degenerate recycling cavities, giving some preliminary results of simulations about the tolerances of this design to astigmatism, mirror figure errors and thermal lensing.

  18. HFSS Simulation on Cavity Coupling for Axion Detecting Experiment

    CERN Document Server

    Yeo, Beomki

    2015-01-01

    In the resonant cavity experiment, it is vital maximize signal power at detector with the minimized reflection from source. Return loss is minimized when the impedance of source and cavity are matched to each other and this is called impedance matching. Establishing tunable antenna on source is required to get a impedance matching. Geometry and position of antenna is varied depending on the electromagnetic eld of cavity. This research is dedicated to simulation to nd such a proper design of coupling antenna, especially for axion dark matter detecting experiment. HFSS solver was used for the simulation.

  19. Deformable two-dimensional photonic crystal slab for cavity optomechanics

    CERN Document Server

    Antoni, T; Briant, T; Cohadon, P -F; Heidmann, A; Braive, R; Beveratos, A; Abram, I; Gatiet, L Le; Sagnes, I; Robert-Philip, I

    2011-01-01

    We have designed photonic crystal suspended membranes with optimized optical and mechanical properties for cavity optomechanics. Such resonators sustain vibration modes in the megahertz range with quality factors of a few thousand. Thanks to a two-dimensional square lattice of holes, their reflectivity at normal incidence at 1064 nm reaches values as high as 95%. These two features, combined with the very low mass of the membrane, open the way to the use of such periodic structures as deformable end-mirrors in Fabry-Perot cavities for the investigation of cavity optomechanical effects

  20. The Superconducting TESLA Cavities

    CERN Document Server

    Aune, B.; Bloess, D.; Bonin, B.; Bosotti, A.; Champion, M.; Crawford, C.; Deppe, G.; Dwersteg, B.; Edwards, D.A.; Edwards, H.T.; Ferrario, M.; Fouaidy, M.; Gall, P-D.; Gamp, A.; Gössel, A.; Graber, J.; Hubert, D.; Hüning, M.; Juillard, M.; Junquera, T.; Kaiser, H.; Kreps, G.; Kuchnir, M.; Lange, R.; Leenen, M.; Liepe, M.; Lilje, L.; Matheisen, A.; Möller, W-D.; Mosnier, A.; Padamsee, H.; Pagani, C.; Pekeler, M.; Peters, H-B.; Peters, O.; Proch, D.; Rehlich, K.; Reschke, D.; Safa, H.; Schilcher, T.; Schmüser, P.; Sekutowicz, J.; Simrock, S.; Singer, W.; Tigner, M.; Trines, D.; Twarowski, K.; Weichert, G.; Weisend, J.; Wojtkiewicz, J.; Wolff, S.; Zapfe, K.

    2000-01-01

    The conceptional design of the proposed linear electron-positron colliderTESLA is based on 9-cell 1.3 GHz superconducting niobium cavities with anaccelerating gradient of Eacc >= 25 MV/m at a quality factor Q0 > 5E+9. Thedesign goal for the cavities of the TESLA Test Facility (TTF) linac was set tothe more moderate value of Eacc >= 15 MV/m. In a first series of 27industrially produced TTF cavities the average gradient at Q0 = 5E+9 wasmeasured to be 20.1 +- 6.2 MV/m, excluding a few cavities suffering fromserious fabrication or material defects. In the second production of 24 TTFcavities additional quality control measures were introduced, in particular aneddy-current scan to eliminate niobium sheets with foreign material inclusionsand stringent prescriptions for carrying out the electron-beam welds. Theaverage gradient of these cavities at Q0 = 5E+9 amounts to 25.0 +- 3.2 MV/mwith the exception of one cavity suffering from a weld defect. Hence only amoderate improvement in production and preparation technique...

  1. Porous photonic crystal external cavity laser biosensor

    Science.gov (United States)

    Huang, Qinglan; Peh, Jessie; Hergenrother, Paul J.; Cunningham, Brian T.

    2016-08-01

    We report the design, fabrication, and testing of a photonic crystal (PC) biosensor structure that incorporates a porous high refractive index TiO2 dielectric film that enables immobilization of capture proteins within an enhanced surface-area volume that spatially overlaps with the regions of resonant electromagnetic fields where biomolecular binding can produce the greatest shifts in photonic crystal resonant wavelength. Despite the nanoscale porosity of the sensor structure, the PC slab exhibits narrowband and high efficiency resonant reflection, enabling the structure to serve as a wavelength-tunable element of an external cavity laser. In the context of sensing small molecule interactions with much larger immobilized proteins, we demonstrate that the porous structure provides 3.7× larger biosensor signals than an equivalent nonporous structure, while the external cavity laser (ECL) detection method provides capability for sensing picometer-scale shifts in the PC resonant wavelength caused by small molecule binding. The porous ECL achieves a record high figure of merit for label-free optical biosensors.

  2. Controlling spin relaxation with a cavity

    Science.gov (United States)

    Bienfait, A.; Pla, J. J.; Kubo, Y.; Zhou, X.; Stern, M.; Lo, C. C.; Weis, C. D.; Schenkel, T.; Vion, D.; Esteve, D.; Morton, J. J. L.; Bertet, P.

    2016-03-01

    Spontaneous emission of radiation is one of the fundamental mechanisms by which an excited quantum system returns to equilibrium. For spins, however, spontaneous emission is generally negligible compared to other non-radiative relaxation processes because of the weak coupling between the magnetic dipole and the electromagnetic field. In 1946, Purcell realized that the rate of spontaneous emission can be greatly enhanced by placing the quantum system in a resonant cavity. This effect has since been used extensively to control the lifetime of atoms and semiconducting heterostructures coupled to microwave or optical cavities, and is essential for the realization of high-efficiency single-photon sources. Here we report the application of this idea to spins in solids. By coupling donor spins in silicon to a superconducting microwave cavity with a high quality factor and a small mode volume, we reach the regime in which spontaneous emission constitutes the dominant mechanism of spin relaxation. The relaxation rate is increased by three orders of magnitude as the spins are tuned to the cavity resonance, demonstrating that energy relaxation can be controlled on demand. Our results provide a general way to initialize spin systems into their ground state and therefore have applications in magnetic resonance and quantum information processing. They also demonstrate that the coupling between the magnetic dipole of a spin and the electromagnetic field can be enhanced up to the point at which quantum fluctuations have a marked effect on the spin dynamics; as such, they represent an important step towards the coherent magnetic coupling of individual spins to microwave photons.

  3. Multilongitudinal-mode model for cleaved coupled-cavity lasers

    Science.gov (United States)

    van de Capelle, J. P.; Baets, R.; Lagasse, P. E.

    1987-02-01

    The multilongitudinal-mode model for the analysis of cleaved coupled-cavity lasers proposed by Van de Capelle et al. (1984) is described in full detail. The model includes the optical interactions between the two cavities as well as the noise (spontaneous emission) in each of the resonators. It takes several longitudinal modes into account simultaneously and solves the nonlinear field equations self-consistently, together with a nonlinear resonance condition for each longitudinal mode. These conditions are coupled with each other through the nonlinearity of the laser medium. The results of this model are compared with those from an analytic model based on an effective mirror concept.

  4. High-sensitivity and high-Q-factor glass photonic crystal cavity and its applications as sensors.

    Science.gov (United States)

    Siraji, Ashfaqul Anwar; Zhao, Yang

    2015-04-01

    We investigate the properties of a planar photonic crystal cavity on glass and its applications as sensors. An airbridged twofold defect cavity on Schott glass background and Gorilla glass substrate has been designed for high Q-factor up to 4459. The average sensitivity of the cavity resonance to background refractive index is 388 nm/Refractive Index Unit. The resonant wavelength is sensitive to background temperature by 18.5 pm/°C. The designed sensors show much higher sensitivity than those based on waveguide interferometers or photonic bandgap structures without cavity resonance. The results are also useful for experimental studies of glass photonic devices.

  5. Engineering three-dimensional maximally entangled states for two modes in a bimodal cavity

    Institute of Scientific and Technical Information of China (English)

    Yang Zhen-Biao; Su Wan-Jun

    2007-01-01

    An alternative scheme is proposed for engineering three-dimensional maximally entangled states for two modes of a superconducting microwave cavity. In this scheme, an appropriately prepared four-level atom is sent through a bimodal cavity. During its passing through the cavity, the atom is coupled resonantly with two cavity modes simultaneously and addressed by a classical microwave pulse tuned to the required transition. Then the atomic states are detected to collapse two modes onto a three-dimensional maximally entangled state. The scheme is different from the previous one in which two nonlocal cavities are used. A comparison between them is also made.

  6. Interference control of nonlinear excitation in a multiatom cavity QED system

    CERN Document Server

    Yang, Guoqing; Zou, Bichen; Zhu, Yifu

    2014-01-01

    We show that by manipulating quantum interference in a multi-atom cavity QED system, the nonlinear excitation of the cavity-atom polariton can be resonantly enhanced while the linear excitation is suppressed. Under appropriate conditions, it is possible to selectively enhance or suppress the polariton excitation with two free-pace laser fields. We report an experiment with cold Rb atoms in an optical cavity and present experimental results that demonstrate such interference control of the cavity QED excitation and its direct applications for studies of all-optical switching and cross-phase modulation of the cavity transmitted light.

  7. Cavity-enhanced ultrafast two-dimensional spectroscopy using higher order modes

    Science.gov (United States)

    Allison, Thomas K.

    2017-02-01

    We describe methods using frequency combs and optical resonators for recording two-dimensional (2D) ultrafast spectroscopy signals with high sensitivity. By coupling multiple frequency combs to higher-order modes of one or more optical cavities, background-free, cavity-enhanced 2D spectroscopy signals are naturally generated via phase cycling. As in cavity-enhanced ultrafast transient absorption spectroscopy, the signal to noise is enhanced by a factor proportional to the cavity finesse squared, so even using cavities of modest finesse, a very high sensitivity is expected, enabling ultrafast 2D spectroscopy experiments in dilute molecular beams.

  8. Cavity-enhanced ultrafast two-dimensional spectroscopy using higher-order modes

    CERN Document Server

    Allison, Thomas K

    2016-01-01

    We describe methods using frequency combs and optical resonators for recording two-dimensional (2D) ultrafast spectroscopy signals with high sensitivity. By coupling multiple frequency combs to higher-order modes of one or more optical cavities, background-free, cavity-enhanced 2D spectroscopy signals are naturally generated via phase cycling. As in cavity-enhanced ultrafast transient absorption spectroscopy (CE-TAS), the signal to noise is enhanced by a factor proportional to the cavity finesse squared, so even using cavities of modest finesse, a very high sensitivity is expected, enabling ultrafast 2D spectroscopy experiments in dilute molecular beams.

  9. Passive Infrared Sensing Using Plasmonic Resonant Dust Particles

    Directory of Open Access Journals (Sweden)

    Mark Mirotznik

    2012-01-01

    Full Text Available We present computational and experimental results of dust particles that can be tuned to preferentially reflect or emit IR radiation within the 8–14 μm band. The particles consist of thin metallic subwavelength gratings patterned on the surface of a simple quarter wavelength cavity. This design creates distinct IR absorption resonances by combining the plasmonic resonance of the grating with the natural resonance of the cavity. We show that the resonance peaks are easily tuned by varying either the geometry of the grating or the thickness of the cavity. Here, we present a computational design algorithm along with experimental results that validate the design methodology.

  10. Selective oxidization cavity confinement for low threshold vertical cavity transistor laser

    Science.gov (United States)

    Wu, M. K.; Liu, M.; Tan, F.; Feng, M.; Holonyak, N.

    2013-07-01

    Data are presented for a low threshold n-p-n vertical cavity transistor laser (VCTL) with improved cavity confinement by trench opening and selective oxidation. The oxide-confined VCTL with a 6.5 × 7.5 μm2 oxide aperture demonstrates a threshold base current of 1.6 mA and an optical power of 150 μW at IB = 3 mA operating at -80 °C due to the mismatch between the quantum well emission peak and the resonant cavity optical mode. The VCTL operation switching from spontaneous to coherent stimulated emission is clearly observed in optical output power L-VCE characteristics. The collector output IC-VCE characteristics demonstrate the VCTL can lase in transistor's forward-active mode with a collector current gain β = 0.48.

  11. Flow-acoustic Characterisation of a Cavity-based Combustor Configuration

    Directory of Open Access Journals (Sweden)

    Krishna Kant Agarwal

    2011-10-01

    Full Text Available This study concerns the flow-acoustic characterisation of a cavity-based combustor configuration. A well-validated numerical tool has been used to simulate the unsteady, two-dimensional reacting flow. Initially, a conventional flow over a cavity with dimensions and conditions corresponding to a compact cavity combustor was studied. Cavity mass injections in the form of fuel and air injections required for trapped vortex formation were then employed and the resonance features of this configuration were studied. The results indicate that the cavity depth mode resonance mechanism is dominant at the conditions studied in this work and that the oscillation frequencies do not change with cavity air injection. This observation is important since it implies that the only important variable which can alter resonant frequencies is the cavity depth. With combustion, the pressure oscillation amplitude was observed to increases significantly due to periodic entrainment of the cavity air jet and fluctuation of fuel-air mixture composition to produce highly fluctuating heat-release rates. The underlying mechanisms of the unsteady flow in the cavity combustor identified in this study indicate the strong dependence of the acoustics on the cavity injection strategies.Defence Science Journal, 2011, 61(6, pp.523-528, DOI:http://dx.doi.org/10.14429/dsj.61.870

  12. Resonance in Bottles with Different Shapes

    Directory of Open Access Journals (Sweden)

    Amy Elliott

    2012-01-01

    Full Text Available The Helmholtz Resonance equation derived in the 1800’s describes the nature of resonance in narrow-necked vessels, known as Helmholtz Resonators. It is commonly accepted that when air is blown across the opening of a bottle, the resonance can be modeled by the Helmholtz equation. Resonance was studied in two differently shaped bottles as the volume of the air cavity was varied. It was found that resonance in one of the bottles was accurately modeled by the Helmholtz equation but not in the other.

  13. Three-dimensional self-consistent simulations of multipacting in superconducting radio frequency cavities

    Energy Technology Data Exchange (ETDEWEB)

    Chet Nieter

    2010-12-01

    Superconducting radio frequency (SRF) cavities are a popular choice among researchers designing new accelerators because of the reduced power losses due to surface resistance. However, SRF cavities still have unresolved problems, including the loss of power to stray electrons. Sources of these electrons are field emission from the walls and ionization of background gas, but the predominant source is secondary emission yield (SEY) from electron impact. When the electron motion is in resonance with the cavity fields the electrons strike the cavity surface repeatedly creating a resonant build up of electrons referred to as multipacting. Cavity shaping has successfully reduced multipacting for cavities used in very high energy accelerators. However, multipacting is still a concern for the cavity power couplers, where shaping is not possible, and for cavities used to accelerate particles at moderate velocities. This Phase II project built upon existing models in the VORPAL simulation framework to allow for simulations of multipacting behavior in SRF cavities and their associated structures. The technical work involved allowed existing models of secondary electron generation to work with the complex boundary conditions needed to model the cavity structures. The types of data produced by VORPAL were also expanded to include data common used by cavity designers to evaluate cavity performance. Post-processing tools were also modified to provide information directly related to the conditions that produce multipacting. These new methods were demonstrated by running simulations of a cavity design being developed by researchers at Jefferson National Laboratory to attempt to identify the multipacting that would be an issue for the cavity design being considered. These simulations demonstrate that VORPAL now has the capabilities to assist researchers working with SRF cavities to understand and identify possible multipacting issues with their cavity designs.

  14. A cavity-Cooper pair transistor scheme for investigating quantum optomechanics in the ultra-strong coupling regime

    Science.gov (United States)

    Rimberg, A. J.; Blencowe, M. P.; Armour, A. D.; Nation, P. D.

    2014-05-01

    We propose a scheme involving a Cooper pair transistor (CPT) embedded in a superconducting microwave cavity, where the CPT serves as a charge tunable quantum inductor to facilitate ultra-strong coupling between photons in the cavity and a nano- to meso-scale mechanical resonator. The mechanical resonator is capacitively coupled to the CPT, such that mechanical displacements of the resonator cause a shift in the CPT inductance and hence the cavity's resonant frequency. The amplification provided by the CPT is sufficient for the zero point motion of the mechanical resonator alone to cause a significant change in the cavity resonance. Conversely, a single photon in the cavity causes a shift in the mechanical resonator position on the order of its zero point motion. As a result, the cavity-Cooper pair transistor coupled to a mechanical resonator will be able to access a regime in which single photons can affect single phonons and vice versa. Realizing this ultra-strong coupling regime will facilitate the creation of non-classical states of the mechanical resonator, as well as the means to accurately characterize such states by measuring the cavity photon field.

  15. A Detection Scheme for Cavity-based Dark Matter Searches

    CERN Document Server

    Bukhari, M H S

    2016-01-01

    We present here proposal of a scheme and some useful ideas for resonant cavity-based detection of cold dark matter axions with hope to improve the existing endeavors. The scheme is based upon our idea of a detector, which incorporates an integrated tunnel diode and a GaAs HEMT or HFET, High Electron Mobility Transistor or Heterogenous FET, for resonance detection and amplification from a resonant cavity (in a strong transverse magnetic field from a cylindrical array of halbach magnets). The idea of a TD-oscillator-amplifier combination could possibly serve as a more sensitive and viable resonance detection regime while maintaining an excellent performance with low noise temperature, whereas the halbach magnets array may offer a compact and permanent solution replacing the conventional electromagnets scheme. We believe that all these factors could possibly increase the sensitivity and accuracy of axion detection searches and reduce complications (and associated costs) in the experiments, in addition to help re...

  16. Isotopic gas analysis through Purcell cavity enhanced Raman scattering

    Science.gov (United States)

    Petrak, B.; Cooper, J.; Konthasinghe, K.; Peiris, M.; Djeu, N.; Hopkins, A. J.; Muller, A.

    2016-02-01

    Purcell enhanced Raman scattering (PERS) by means of a doubly resonant Fabry-Perot microcavity (mode volume ≈ 100 μm3 and finesse ≈ 30 000) has been investigated as a technique for isotopic ratio gas analysis. At the pump frequency, the resonant cavity supports a buildup of circulating power while simultaneously enabling Purcell spontaneous emission rate enhancement at the resonant Stokes frequency. The three most common isotopologues of CO2 gas were quantified, and a signal was obtained from 13C16O2 down to a partial pressure of 2 Torr. Due to its small size and low pump power needed (˜10 mW) PERS lends itself to miniaturization. Furthermore, since the cavity is resonant with the emission frequency, future improvements could allow it to serve as its own spectral analyzer and no separate spectroscopic device would be needed.

  17. Acoustic mode coupling of two facing, shallow cylindrical cavities

    Science.gov (United States)

    McCarthy, Philip; Ekmekci, Alis

    2016-11-01

    Cavity mode excitation by grazing flows is a well-documented source for noise generation. Similarly to their rectangular equivalents, single cylindrical cavities have been shown to exhibit velocity dependent self-sustaining feedback mechanisms that produce significant tonal noise. The present work investigates the effect of cavity mode coupling on the tonal noise generation for two facing, shallow cylindrical cavities. This geometric arrangement may occur for constrained flows, such as those within ducts, silencers or between aircraft landing gear wheels. For the latter configuration, the present study has observed that the tonal frequency dependence upon the freestream Mach number, associated with the single cavity feedback mechanism, no longer holds true. Instead, two simultaneously present and distinct large amplitude tones that are independent (in frequency) of speed, propagate to the far field. These two, fixed frequency tones are attributable to the first order transverse mode, and the first order transverse and azimuthal modes for the two combined cavities and the volume between them. Altering either the cavity aspect ratio or the inter-cavity spacing thus changes the acoustic resonant volume and translates the centre frequencies of the observed tones correspondingly. The authors would like to thank Bombardier and Messier-Bugatti-Dowty for their continued support.

  18. Metasurface external cavity laser

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Luyao, E-mail: luyaoxu.ee@ucla.edu; Curwen, Christopher A.; Williams, Benjamin S. [Department of Electrical Engineering, University of California, Los Angeles, California 90095 (United States); California NanoSystems Institute, University of California, Los Angeles, California 90095 (United States); Hon, Philip W. C.; Itoh, Tatsuo [Department of Electrical Engineering, University of California, Los Angeles, California 90095 (United States); Chen, Qi-Sheng [Northrop Grumman Aerospace Systems, Redondo Beach, California 90278 (United States)

    2015-11-30

    A vertical-external-cavity surface-emitting-laser is demonstrated in the terahertz range, which is based upon an amplifying metasurface reflector composed of a sub-wavelength array of antenna-coupled quantum-cascade sub-cavities. Lasing is possible when the metasurface reflector is placed into a low-loss external cavity such that the external cavity—not the sub-cavities—determines the beam properties. A near-Gaussian beam of 4.3° × 5.1° divergence is observed and an output power level >5 mW is achieved. The polarized response of the metasurface allows the use of a wire-grid polarizer as an output coupler that is continuously tunable.

  19. Cavity tests of parity-odd Lorentz violations in electrodynamics

    Science.gov (United States)

    Mewes, Matthew; Petroff, Alexander

    2007-03-01

    Electromagnetic resonant cavities form the basis for a number modern tests of Lorentz invariance. The geometry of most of these experiments implies unsuppressed sensitivities to parity-even Lorentz violations only. Parity-odd violations typically enter through suppressed boost effects, causing a reduction in sensitivity by roughly 4 orders of magnitude. Here we discuss possible techniques for achieving unsuppressed sensitivities to parity-odd violations using asymmetric resonators.

  20. Multipacting phenomenon at high electric fields of superconducting cavities

    Institute of Scientific and Technical Information of China (English)

    Zhu Feng; D.Proch; Hao Jian-Kui

    2005-01-01

    Recently multipacting(MP) recalculation of the TeV Energy Superconductiong Linear Accelerator (TESLA)resonator was performed. In addition to the normal MP which occurs at a peak electric field of around 40MV/m for the TESLA cavity, another type of multipacting with resonant electron trajectory that is far from the equator is also seen.It occurs at a gradient around 60MV/m to 70MV/m. This result seems to explain some experimental observations.

  1. Novel deflecting cavity design for eRHIC

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Q.; Belomestnykh, S.; Ben-Zvi, I.

    2011-07-25

    To prevent significant loss of the luminosity due to large crossing angle in the future ERL based Electron Ion Collider at BNL (eRHIC), there is a demand for crab cavities. In this article, we will present a novel design of the deflecting/crabbing 181 MHz superconducting RF cavity that will fulfil the requirements of eRHIC. The quarter-wave resonator structure of the new cavity possesses many advantages, such as compact size, high R{sub t}/Q, the absence of the same order mode and lower order mode, and easy higher order mode damping. We will present the properties and characteristics of the new cavity in detail. As the accelerator systems grow in complexity, developing compact and efficient deflecting cavities is of great interest. Such cavities will benefit situations where the beam line space is limited. The future linac-ring type electron-ion collider requires implementation of a crab-crossing scheme for both beams at the interaction region. The ion beam has a long bunches and high rigidity. Therefore, it requires a low frequency, large kicking angle deflector. The frequency of the deflecting mode for the current collider design is 181 MHz, and the deflecting angle is {approx}5 mrad for each beam. At such low frequency, the previous designs of the crab cavities will have very large dimensions, and also will be confronted by typical problems of damping the Lower Order Mode (LOM), the Same Order Mode (SOM), and as usual, the Higher Order Modes (HOM). In this paper we describe how one can use the concept of a quarter-wave (QW) resonator for a deflecting/crabbing cavity, and use its fundamental mode to deflect the beam. The simplicity of the cavity geometry and the large separation between its fundamental mode and the first HOM make it very attractive.

  2. Experimental investigation of cavity flows

    Energy Technology Data Exchange (ETDEWEB)

    Loeland, Tore

    1998-12-31

    This thesis uses LDV (Laser Doppler Velocimetry), PIV (Particle Image Velocimetry) and Laser Sheet flow Visualisation to study flow inside three different cavity configurations. For sloping cavities, the vortex structure inside the cavities is found to depend upon the flow direction past the cavity. The shape of the downstream corner is a key factor in destroying the boundary layer flow entering the cavity. The experimental results agree well with numerical simulations of the same geometrical configurations. The results of the investigations are used to find the influence of the cavity flow on the accuracy of the ultrasonic flowmeter. A method to compensate for the cavity velocities is suggested. It is found that the relative deviation caused by the cavity velocities depend linearly on the pipe flow. It appears that the flow inside the cavities should not be neglected as done in the draft for the ISO technical report on ultrasonic flowmeters. 58 refs., 147 figs., 2 tabs.

  3. Dispersive radiation induced by shock waves in passive resonators.

    Science.gov (United States)

    Malaguti, Stefania; Conforti, Matteo; Trillo, Stefano

    2014-10-01

    We show that passive Kerr resonators pumped close to zero dispersion wavelengths on the normal dispersion side can develop the resonant generation of linear waves driven by cavity (mixed dispersive-dissipative) shock waves. The resonance mechanism can be successfully described in the framework of the generalized Lugiato-Lefever equation with higher-order dispersive terms. Substantial differences with radiation from cavity solitons and purely dispersive shock waves dispersion are highlighted.

  4. Cavity techniques for holographic data storage recording.

    Science.gov (United States)

    Miller, Bo E; Takashima, Yuzuru

    2016-03-21

    Conventionally, reading and writing of data holograms utilizes a fraction of the light power because of a trade off in write and read efficiencies. This system constraint can be mitigated by applying a resonator cavity. Cavities enable more efficient use of the available light leading to enhanced read and write data rates with no additional energy cost. This enhancement is inversely related to diffraction efficiency, so these techniques work well for large capacity holographic data storage having low diffraction efficiency. The enhancement in write data transfer rate is evaluated by writing plane wave holograms and image bearing holograms in Fe:LiNbO3 with a 532 nm wavelength laser. We confirmed 1.2 times enhancement in write data rate, out of a 1.4 theoretical maximum for materials absorption of 16%.

  5. HOM Couplers for CERN SPL Cavities

    CERN Document Server

    Papke, Kai; Van Rienen, U

    2013-01-01

    Higher-Order-Modes (HOMs) may affect beam stability and refrigeration requirements of superconducting proton linacs such as the SPL, which is studied at CERN as the driver for future neutrino facilities. In order to limit beam-induced HOM effects, CERN considers the use of HOM couplers on the cut-off tubes of the 5-cell superconducting cavities. These couplers consist of resonant antennas shaped as loops or probes, which are designed to couple to modes of a specific frequency range. In this paper the design process is presented and a comparison is made between various design options for the medium and high-beta SPL cavities, both operating at 704.4 MHz. The RF characteristics and thermal behaviour of the various designs are discussed.

  6. Modeling of Coupled Nano-Cavity Lasers

    DEFF Research Database (Denmark)

    Skovgård, Troels Suhr

    Modeling of nanocavity light emitting semiconductor devices is done using the semiconductor laser rate equations with spontaneous and stimulated emission terms modified for Purcell enhanced recombination. The modified terms include details about the optical and electronic density......, coupled photonic crystal nanocavity structures are simulated. The resonance frequencies of in-phase and out-of-phase coupled quadrupole modes in rectangular photonic crystal H1 cavities are extracted and are found to vary non-trivially with the intercavity separation. A qualitative explanation is given...... in terms of the in-plane mode profiles. Fareld emission patterns for the structures are calculated based on the finite-dierence time-domain simulations. It is found that only systems with an even number of holes separating the cavities show clear signs of being coupled. This non-trivial coupling behavior...

  7. Interference control of perfect photon absorption in cavity quantum electrodynamics

    CERN Document Server

    Wang, Liyong; Zhu, Yifu; Agarwal, G S

    2016-01-01

    We propose and analyze a scheme for controlling coherent photon transmission and reflection in a cavity-quantum-electrodynamics (CQED) system consisting of an optical resonator coupled with three-level atoms coherently prepared by a control laser from free space. When the control laser is off and the cavity is excited by two identical light fields from two ends of the cavity, the two input light fields can be completely absorbed by the CQED system and the light energy is converted into the excitation of the polariton states, but no light can escape from the cavity. Two distinct cases of controlling the perfect photon absorption are analyzed: (a) when the control laser is tuned to the atomic resonance and creates electromagnetically induced transparency, the prefect photon absorption is suppressed and the input light fields are nearly completely transmitted through the cavity; (b) when the control laser is tuned to the polariton state resonance and inhibits the polariton state excitation, the perfect photon ab...

  8. Design and prototyping of HL-LHC double quarter wave crab cavities for SPS test

    Energy Technology Data Exchange (ETDEWEB)

    Verdu-Andres, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Skaritka, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Wu, Q. [Brookhaven National Lab. (BNL), Upton, NY (United States); Xiao, B. [Brookhaven National Lab. (BNL), Upton, NY (United States); Belomestnykh, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., NY (United States); Ben-Zvi, I. [Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., NY (United States); Alberty, L. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Artoos, K. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Calaga, R. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Capatina, O. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Capelli, T. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Carra, F. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Leuxe, R. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Kuder, N. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Zanoni, C. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Li, Z. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Ratti, A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-05-03

    The LHC high luminosity project envisages the use of the crabbing technique for increasing and levelling the LHC luminosity. Double Quarter Wave (DQW) resonators are compact cavities especially designed to meet the technical and performance requirements for LHC beam crabbing. Two DQW crab cavities are under fabrication and will be tested with beam in the Super Proton Synchrotron (SPS) at CERN by 2017. This paper describes the design and prototyping of the DQW crab cavities for the SPS test.

  9. Design and Prototyping of HL-LHC Double Quarter Wave Crab Cavities for SPS Test

    CERN Document Server

    Verdú-Andrés, S; Wu, Q; Xiao, B P; Belomestnykh, S; Ben-Zv, I; Alberty, L; Artoos, Kurt; Calaga, Rama; Capatina, Ofelia; Capelli, Teddy; Carra, Federico; Leuxe, Raphael; Kuder, Norbert; Zanoni, Carlo; Li, Z; Ratti, A

    2015-01-01

    The LHC high luminosity project envisages the use of the crabbing technique for increasing and levelling the LHC luminosity. Double Quarter Wave (DQW) resonators are compact cavities especially designed to meet the technical and performance requirements for LHC beam crabbing. Two DQW crab cavities are under fabrication and will be tested with beam in the Super Proton Synchrotron (SPS) at CERN by 2017. This paper describes the design and prototyping of the DQW crab cavities for the SPS test.

  10. Entanglement swapping without joint measurement via a Λ-type atom interacting with bimodal cavity field

    Institute of Scientific and Technical Information of China (English)

    Lin Xiu; Li Hong-Cai; Yang Rong-Can; Huang Zhi-Ping

    2007-01-01

    This paper proposes a scheme for realizing entanglement swapping in cavity QED. The scheme is based on the resonant interaction of a two-mode cavity field with a A-type three-level atom. In contrast with the previously proposed schemes, the present scheme is ascendant, since the fidelity is 1.0 and the joint measurement isn't needed. And the scheme is experimentally feasible based on the current cavity QED technique.

  11. Plasmonic external cavity laser refractometric sensor.

    Science.gov (United States)

    Zhang, Meng; Lu, Meng; Ge, Chun; Cunningham, Brian T

    2014-08-25

    Combining the high sensitivity properties of surface plasmon resonance refractive index sensing with a tunable external cavity laser, we demonstrate a plasmonic external cavity laser (ECL) for high resolution refractometric sensing. The plasmonic ECL utilizes a plasmonic crystal with extraordinary optical transmission (EOT) as the wavelength-selective element, and achieves single mode lasing at the transmission peak of the EOT resonance. The plasmonic ECL refractometric sensor maintains the high sensitivity of a plasmonic crystal sensor, while simultaneously providing a narrow spectral linewidth through lasing emission, resulting in a record high figure of merit for refractometric sensing with an active or passive optical resonator. We demonstrate single-mode and continuous-wave operation of the electrically-pumped laser system, and show the ability to measure refractive index changes with a 3σ detection limit of 1.79 × 10(-6) RIU. The demonstrated approach is a promising path towards label-free optical biosensing with enhanced signal-to-noise ratios for challenging applications in small molecule drug discovery and pathogen sensing.

  12. Magneto-induced Fano-like cavity interference in three-dimensional metamaterials

    Science.gov (United States)

    Pan, Xun-Yong; Wang, Gaofeng

    2016-08-01

    Fano-like cavity interference due to magneto-inductive coupling in metamaterial structure is demonstrated via a double Fabry-Perot cavity (DFPC) that consists of stacked multi-layered resonators. The induced magnetic field based destructive interference is observed in the transmission response of the DFPC system, which exhibits the Fano line shaped resonance. The retrieved real and imaginary parts of effective permeability and permittivity indicate strong magneto-induced dispersion with a group delay leading to the slow light effect. This finding provides an interesting mechanism to excite Fano resonances in metamaterial systems via magnetic interaction between resonators, which may enable new devices for slow light and sensing applications.

  13. Niobium superconducting cavity

    CERN Multimedia

    1980-01-01

    This 5-cell superconducting cavity, made from bulk-Nb, stems from the period of general studies, not all directed towards direct use at LEP. This one is dimensioned for 1.5 GHz, the frequency used at CEBAF and also studied at Saclay (LEP RF was 352.2 MHz). See also 7908227, 8007354, 8209255, 8210054, 8312339.

  14. Vertical cavity laser

    DEFF Research Database (Denmark)

    2016-01-01

    The present invention provides a vertical cavity laser comprising a grating layer comprising an in-plane grating, the grating layer having a first side and having a second side opposite the first side and comprising a contiguous core grating region having a grating structure, wherein an index...

  15. LEP superconducting cavity

    CERN Multimedia

    1995-01-01

    Engineers work in a clean room on one of the superconducting cavities for the upgrade to the LEP accelerator, known as LEP-2. The use of superconductors allow higher electric fields to be produced so that higher beam energies can be reached.

  16. Melatonin and oral cavity.

    Science.gov (United States)

    Cengiz, Murat İnanç; Cengiz, Seda; Wang, Hom-Lay

    2012-01-01

    While initially the oral cavity was considered to be mainly a source of various bacteria, their toxins and antigens, recent studies showed that it may also be a location of oxidative stress and periodontal inflammation. Accordingly, this paper focuses on the involvement of melatonin in oxidative stress diseases of oral cavity as well as on potential therapeutic implications of melatonin in dental disorders. Melatonin has immunomodulatory and antioxidant activities, stimulates the proliferation of collagen and osseous tissue, and acts as a protector against cellular degeneration associated with aging and toxin exposure. Arising out of its antioxidant actions, melatonin protects against inflammatory processes and cellular damage caused by the toxic derivates of oxygen. As a result of these actions, melatonin may be useful as a coadjuvant in the treatment of certain conditions of the oral cavity. However, the most important effect of melatonin seems to result from its potent antioxidant, immunomodulatory, protective, and anticancer properties. Thus, melatonin could be used therapeutically for instance, locally, in the oral cavity damage of mechanical, bacterial, fungal, or viral origin, in postsurgical wounds caused by tooth extractions and other oral surgeries. Additionally, it can help bone formation in various autoimmunological disorders such as Sjorgen syndrome, in periodontal diseases, in toxic effects of dental materials, in dental implants, and in oral cancers.

  17. Melatonin and Oral Cavity

    Directory of Open Access Journals (Sweden)

    Murat İnanç Cengiz

    2012-01-01

    Full Text Available While initially the oral cavity was considered to be mainly a source of various bacteria, their toxins and antigens, recent studies showed that it may also be a location of oxidative stress and periodontal inflammation. Accordingly, this paper focuses on the involvement of melatonin in oxidative stress diseases of oral cavity as well as on potential therapeutic implications of melatonin in dental disorders. Melatonin has immunomodulatory and antioxidant activities, stimulates the proliferation of collagen and osseous tissue, and acts as a protector against cellular degeneration associated with aging and toxin exposure. Arising out of its antioxidant actions, melatonin protects against inflammatory processes and cellular damage caused by the toxic derivates of oxygen. As a result of these actions, melatonin may be useful as a coadjuvant in the treatment of certain conditions of the oral cavity. However, the most important effect of melatonin seems to result from its potent antioxidant, immunomodulatory, protective, and anticancer properties. Thus, melatonin could be used therapeutically for instance, locally, in the oral cavity damage of mechanical, bacterial, fungal, or viral origin, in postsurgical wounds caused by tooth extractions and other oral surgeries. Additionally, it can help bone formation in various autoimmunological disorders such as Sjorgen syndrome, in periodontal diseases, in toxic effects of dental materials, in dental implants, and in oral cancers.

  18. Finemet cavity impedance studies

    CERN Document Server

    Persichelli, S; Migliorati, M; Salvant, B

    2013-01-01

    The aim of the study is to evaluate the impedance of the Finemet kicker cavity to be installed in the PS straight section 02 during LS1, under realistic assumptions of bunch length. Time domain simulations with CST Particle Studio have been performed in order to get the impedance of the cavity and make a comparison with the longitudinal impedance measured for a single cell prototype. The study has been performed on simplified 3D geometries imported from a mechanical CATIA drawing, assuming that the simplications have small impact on the nal results. Simulations confirmed that the longitudinal impedance observed with measurements can be excited by bunches circulating in the PS. In the six-cells Finemet cavity, PS bunches circulating in the center can excite a longitudinal impedance, the real part of which has a maximum of 2 kOhm at 4 MHz. This mode does not seem to have any transverse component. All the eigenmodes of the cavity are strongly damped by the Finemet rings: we predict to have no issues regarding tr...

  19. Statistical electromagnetics: Complex cavities

    NARCIS (Netherlands)

    Naus, H.W.L.

    2008-01-01

    A selection of the literature on the statistical description of electromagnetic fields and complex cavities is concisely reviewed. Some essential concepts, for example, the application of the central limit theorem and the maximum entropy principle, are scrutinized. Implicit assumptions, biased choic

  20. Filling a Conical Cavity

    Science.gov (United States)

    Nye, Kyle; Eslam-Panah, Azar

    2016-11-01

    Root canal treatment involves the removal of infected tissue inside the tooth's canal system and filling the space with a dense sealing agent to prevent further infection. A good root canal treatment happens when the canals are filled homogeneously and tightly down to the root apex. Such a tooth is able to provide valuable service for an entire lifetime. However, there are some examples of poorly performed root canals where the anterior and posterior routes are not filled completely. Small packets of air can be trapped in narrow access cavities when restoring with resin composites. Such teeth can cause trouble even after many years and lead the conditions like acute bone infection or abscesses. In this study, the filling of dead-end conical cavities with various liquids is reported. The first case studies included conical cavity models with different angles and lengths to visualize the filling process. In this investigation, the rate and completeness at which a variety of liquids fill the cavity were observed to find ideal conditions for the process. Then, a 3D printed model of the scaled representation of a molar with prepared post spaces was used to simulate the root canal treatment. The results of this study can be used to gain a better understanding of the restoration for endodontically treated teeth.

  1. Middle ear cavity morphology is consistent with an aquatic origin for testudines.

    Directory of Open Access Journals (Sweden)

    Katie L Willis

    Full Text Available The position of testudines in vertebrate phylogeny is being re-evaluated. At present, testudine morphological and molecular data conflict when reconstructing phylogenetic relationships. Complicating matters, the ecological niche of stem testudines is ambiguous. To understand how turtles have evolved to hear in different environments, we examined middle ear morphology and scaling in most extant families, as well as some extinct species, using 3-dimensional reconstructions from micro magnetic resonance (MR and submillimeter computed tomography (CT scans. All families of testudines exhibited a similar shape of the bony structure of the middle ear cavity, with the tympanic disk located on the rostrolateral edge of the cavity. Sea Turtles have additional soft tissue that fills the middle ear cavity to varying degrees. When the middle ear cavity is modeled as an air-filled sphere of the same volume resonating in an underwater sound field, the calculated resonances for the volumes of the middle ear cavities largely fell within testudine hearing ranges. Although there were some differences in morphology, there were no statistically significant differences in the scaling of the volume of the bony middle ear cavity with head size among groups when categorized by phylogeny and ecology. Because the cavity is predicted to resonate underwater within the testudine hearing range, the data support the hypothesis of an aquatic origin for testudines, and function of the middle ear cavity in underwater sound detection.

  2. High-Q cavity-induced fluxon bunching in inductively coupled Josephson junctions

    DEFF Research Database (Denmark)

    Madsen, S.; Grønbech-Jensen, Niels; Pedersen, Niels Falsig;

    2008-01-01

    We consider fluxon dynamics in a stack of inductively coupled long Josephson junctions connected capacitively to a common resonant cavity at one of the boundaries. We study, through theoretical and numerical analyses, the possibility for the cavity to induce a transition from the energetically...

  3. Phonon-dressed Mollow triplet in the regime of cavity quantum electrodynamics: excitation-induced dephasing and nonperturbative cavity feeding effects.

    Science.gov (United States)

    Roy, C; Hughes, S

    2011-06-17

    We study the resonance fluorescence spectra of a driven quantum dot placed inside a high-Q semiconductor cavity and interacting with an acoustic phonon bath. The dynamics is calculated using a time-convolutionless master equation in the polaron frame. We predict pronounced spectral broadening of the Mollow sidebands through off-resonant cavity emission which, for small cavity-coupling rates, increases quadratically with the Rabi frequency in direct agreement with recent experiments using semiconductor micropillars [S. M. Ulrich et al., preceding Letter, Phys. Rev. Lett. 106, 247402 (2011)]. We also demonstrate that, surprisingly, phonon coupling actually helps resolve signatures of the elusive second rungs of the Jaynes-Cummings ladder states via off-resonant cavity feeding. Both multiphonon and multiphoton effects are shown to play a qualitatively important role on the fluorescence spectra.

  4. Cavity flow. Citations from the NTIS data base

    Science.gov (United States)

    Habercom, G. E., Jr.

    1980-05-01

    Reports are cited on shallow and deep configurations, holes, cutouts, hollows, notches, gaps, orifices, flaps, and steps. Applications include bomb bays, aerodynamic windows, microwave cavitites, resonators, diffusers, laser cavities, and jets. This updated bibliography contains 260 abstracts, 29 of which are new entries to the previous edition.

  5. Long Josephson Junction Stack Coupled to a Cavity

    DEFF Research Database (Denmark)

    Madsen, Søren Peder; Pedersen, Niels Falsig; Groenbech-Jensen, N.

    2007-01-01

    A stack of inductively coupled long Josephson junctions are modeled as a system of coupled sine-Gordon equations. One boundary of the stack is coupled electrically to a resonant cavity. With one fluxon in each Josephson junction, the inter-junction fluxon forces are repulsive. We look at a possible...

  6. Cavity quantum electrodynamics with a Rydberg-blocked atomic ensemble

    DEFF Research Database (Denmark)

    Guerlin, Christine; Brion, Etienne; Esslinger, Tilman

    2010-01-01

    The realization of a Jaynes-Cummings model in the optical domain is proposed for an atomic ensemble. The scheme exploits the collective coupling of the atoms to a quantized cavity mode and the nonlinearity introduced by coupling to high-lying Rydberg states. A two-photon transition resonantly...... effective Jaynes-Cummings model. We use numerical simulations to show that the cavity transmission can be used to reveal detailed properties of the Jaynes-Cummings ladder of excited states and that the atomic nonlinearity gives rise to highly nontrivial photon emission from the cavity. Finally, we suggest...... couples the single-atom ground state |g> to a Rydberg state |e>via a nonresonant intermediate state |i>, but due to the interaction between Rydberg atoms only a single atom can be resonantly excited in the ensemble. This restricts the state space of the ensemble to the collective ground state |G...

  7. Higher Order Reentrant Post Modes in Cylindrical Cavities

    CERN Document Server

    McAllister, Ben T; Parker, Stephen R; Tobar, Michael E

    2016-01-01

    Reentrant cavities are microwave resonant devices employed in a number of different areas of physics. They are appealing due to their simple frequency tuning mechanism, which offers large tuning ranges. Reentrant cavities are, in essence, 3D lumped LC circuits consisting of a conducting central post embedded in a resonant cavity. The lowest order reentrant mode (which transforms from the TM010 mode) has been extensively studied in past publications. In this work we show the existence of higher order reentrant post modes (which transform from the TM01n mode family). We characterize these new modes in terms of their frequency tuning, filling factors and quality factors, as well as discuss some possible applications of these modes in fundamental physics tests.

  8. All-Optical Switching in Photonic Crystal Cavities

    DEFF Research Database (Denmark)

    Heuck, Mikkel

    All-Optical switching in photonic crystal waveguide-cavity structures is studied predominantly theoretically and numerically, but also from an experimental point of view. We have calculated the first order perturbations to the resonance frequency and decay rate of cavity modes, using a mathematical...... separated. This device was fabricated and characterized by colleagues within the group, and it was shown to perform very well in terms of cross-talk between the signal and pump. Theoretical investigations as well as practical design proposals have resulted from a study of waveguide-cavity structures...... exhibiting Fano resonances. These devices were predicted to be superior to structures with the more well-known Lorentzian line shape in terms of energy consumption and switching contrast. Finally, the mathematical framework of optimal control theory was employed as a general setting, in which the optical...

  9. Statistical Properties of Antenna Impedance in an Electrically Large Cavity

    Energy Technology Data Exchange (ETDEWEB)

    WARNE,LARRY K.; LEE,KELVIN S.H.; HUDSON,H. GERALD; JOHNSON,WILLIAM A.; JORGENSON,ROY E.; STRONACH,STEPHEN L.

    2000-12-13

    This paper presents models and measurements of antenna input impedance in resonant cavities at high frequencies.The behavior of input impedance is useful in determining the transmission and reception characteristics of an antenna (as well as the transmission characteristics of certain apertures). Results are presented for both the case where the cavity is undermoded (modes with separate and discrete spectra) as well as the over moded case (modes with overlapping spectra). A modal series is constructed and analyzed to determine the impedance statistical distribution. Both electrically small as well as electrically longer resonant and wall mounted antennas are analyzed. Measurements in a large mode stirred chamber cavity are compared with calculations. Finally a method based on power arguments is given, yielding simple formulas for the impedance distribution.

  10. Comparison of Different Numerical Methods for Quality Factor Calculation of Nano and Micro Photonic Cavities

    DEFF Research Database (Denmark)

    Taghizadeh, Alireza; Mørk, Jesper; Chung, Il-Sug

    2014-01-01

    Four different numerical methods for calculating the quality factor and resonance wavelength of a nano or micro photonic cavity are compared. Good agreement was found for a wide range of quality factors. Advantages and limitations of the different methods are discussed.......Four different numerical methods for calculating the quality factor and resonance wavelength of a nano or micro photonic cavity are compared. Good agreement was found for a wide range of quality factors. Advantages and limitations of the different methods are discussed....

  11. PM noise of a 40 GHz air-dielectric cavity oscillator

    OpenAIRE

    Hati, Archita; Nelson, Craig W.; Riddle, B.; Howe, David A.

    2014-01-01

    We describe the design of a low-phase-modulated (PM) noise, 40 GHz oscillator that uses a conventional air-dielectric cavity resonator as a frequency discriminator to improve the PM noise of a commercial 10 GHz dielectric resonator oscillator (DRO) frequency multiplied by four. The main features of this design incorporate (1) unloaded cavity quality factor (Q) of 30,000, (2) high coupling coefficient, (3) large carrier suppression by use of interferometric signal processing, (4) large operati...

  12. Resonance vector mode locking

    CERN Document Server

    Kolpakov, Stanislav A; Loika, Yuri; Tarasov, Nikita; Kalashnikov, Vladimir; Agrawal, Govind P

    2015-01-01

    A mode locked fibre laser as a source of ultra-stable pulse train has revolutionised a wide range of fundamental and applied research areas by offering high peak powers, high repetition rates, femtosecond range pulse widths and a narrow linewidth. However, further progress in linewidth narrowing seems to be limited by the complexity of the carrier-envelope phase control. Here for the first time we demonstrate experimentally and theoretically a new mechanism of resonance vector self-mode locking where tuning in-cavity birefringence leads to excitation of the longitudinal modes sidebands accompanied by the resonance phase locking of sidebands with the adjacent longitudinal modes. An additional resonance with acoustic phonons provides the repetition rate tunability and linewidth narrowing down to Hz range that drastically reduces the complexity of the carrier-envelope phase control and so will open the way to advance lasers in the context of applications in metrology, spectroscopy, microwave photonics, astronomy...

  13. Teleportation of Cavity Field States via Cavity QED

    CERN Document Server

    Guerra, E S

    2004-01-01

    In this article we discuss two schemes of teleportation of cavity field states. In the first scheme we consider cavities prepared in a coherent state and in the second scheme we consider cavities prepared in a superposition of zero and one Fock states.

  14. Critical coupling in plasmonic resonator arrays

    Science.gov (United States)

    Balci, Sinan; Kocabas, Coskun; Aydinli, Atilla

    2011-08-01

    We report critical coupling of electromagnetic waves to plasmonic cavity arrays fabricated on Moiré surfaces. Dark field plasmon microscopy imaging and polarization dependent spectroscopic reflection measurements reveal the critical coupling conditions of the cavities. The critical coupling conditions depend on the superperiod of the Moiré surface, which also defines the coupling between the cavities. Complete transfer of the incident power can be achieved for traveling wave plasmonic resonators, which have a relatively short superperiod. When the superperiod of the resonators increases, the coupled resonators become isolated standing wave resonators in which complete transfer of the incident power is not possible. Analytical and finite difference time domain calculations support the experimental observations.

  15. Nonlinear behavior of Helmholtz resonators

    Science.gov (United States)

    Hersh, A. S.

    1990-10-01

    A semi-empirical fluid mechanical model has been derived to predict the nonlinear acoustic behavior of thin-walled, single-orifice Helmholtz resonators. The model assumed that the sound particle velocity field approaches the resonator in a spherically symmetric manner. The incident and cavity sound pressure fields are connected in terms of an orifice discharge coefficient and an end correction parameter whose values are determined empirically. The accuracy of the model was verified by comparing predicted with measured impedance over a wide range of sound amplitudes and frequencies for two different resonator geometries and with measurements conducted by Ingard and Ising.

  16. Sound-resonance hydrogen sensor

    OpenAIRE

    Dong, Shuxiang; Bai, Feiming; Li, Jiefang; Viehland, Dwight D.

    2003-01-01

    A hydrogen sensor is reported in which a small piezoelectric-sound-resonance-cavity (PSRC) is used as the sensing element. Detection utilizes sound resonance and acoustic property differences between H-2 and air as a sensing mechanism. Changes in H-2 concentration result in a shift of the sound-resonance state of the PSRC. Preliminary experiments have demonstrated a sensitivity limit of 8 ppm, a fast response time similar to1.5 second, and detection capabilities over a broad concentration ran...

  17. Controllable coupling of distributed qubits within a microtoroidal cavity network

    Science.gov (United States)

    Hu, C.; Xia, Y.; Song, J.

    2012-05-01

    We propose a scheme to control the coupling between two arbitrary atoms scattered within a quantum network composed of microtoroidal cavities linked by a ring-fibre. The atom-atom effective couplings are induced by pairing of off-resonant Raman transitions. The couplings can be arbitrarily controlled by adjusting classical fields. Compared with the previous scheme [S.B. Zheng, C.P. Yang, F. Nori, Phys. Rev. A 82, 042327 (2010)], the present scheme uses microtoroidal cavities with higher coupling efficiency than Fabry-Perot cavities. Furthermore, the scheme is not only suitable for the short-fibre limit, but also for multiple fibre modes. The added fibre modes can play a positive role, especially when the coupling rate between cavity-mode and fibre-mode is not large. In addition, a wider frequency domain of fibre modes can be used in this scheme.

  18. Bunching of temporal cavity solitons via forward Brillouin scattering

    CERN Document Server

    Erkintalo, Miro; Jang, Jae K; Coen, Stéphane; Murdoch, Stuart G

    2015-01-01

    We report on the experimental observation of bunching dynamics with temporal cavity solitons in a continuously-driven passive fibre resonator. Specifically, we excite a large number of ultrafast cavity solitons with random temporal separations, and observe in real time how the initially random sequence self-organizes into regularly-spaced aggregates. To explain our experimental observations, we develop a simple theoretical model that allows long-range acoustically-induced interactions between a large number of temporal cavity solitons to be simulated. Significantly, results from our simulations are in excellent agreement with our experimental observations, strongly suggesting that the soliton bunching dynamics arise from forward Brillouin scattering. In addition to confirming prior theoretical analyses and unveiling a new cavity soliton self-organization phenomenon, our findings elucidate the manner in which sound interacts with large ensembles of ultrafast pulses of light.

  19. Entanglement dynamics of two distant atoms in two detuning cavities

    Institute of Scientific and Technical Information of China (English)

    Ji Xin; L(u) Tian-Quan; Zhang Shou

    2010-01-01

    We investigate the entanglement dynamics via the concurrence of two distant atoms interacting off-resonantly with two cavity fields in Fock states, respectively. We find that the evolution of entanglement has sudden death and sudden birth phenomena, that with the increase of photon numbers in the two cavities, the alternate frequency of sudden death and sudden birth turns fast, and that the amplitude of concurrence oscillates regularly with oscillation frequency becoming slow when the cavity fields have the same photon numbers. While, the maximum of concurrence declines and the amplitude of concurrence oscillates irregularly when the two cavity fields have different photon numbers. In addition, we find the length of death time is dependent on the initial entanglement.

  20. Hie-Isolde High Beta Cavity Study and Measurements

    CERN Document Server

    D'Elia, A; Pasini, M

    2009-01-01

    The upgrade of the ISOLDE machine at CERN foresees a superconducting linac based on two gap independently phased Nb sputtered Quarter Wave Resonators (QWRs) working at 101.28MHz and producing an accelerating field of 6MV/m on axis. A careful study of the fields in the cavity has been carried out in order to pin down the crucial e-m parameters of the structure such as peak fields, quality factor and e-m power dissipated on the cavity wall. A tuning system with about 200kHz frequency range has been developed in order to cope with fabrication tolerances. In this paper we will report on the cavity simulations. The tuning plate design will be described. Finally the frequency measurements on a cavity prototype at room temperature will be presented.

  1. Transverse Field Perturbation For PIP-II SRF Cavities

    Energy Technology Data Exchange (ETDEWEB)

    Berrutti, Paolo [Fermilab; Khabiboulline, Timergali N. [Fermilab; Lebedev, Valeri [Fermilab; Yakovlev, Vyacheslav P. [Fermilab

    2015-06-01

    Proton Improvement Plan II (PIP-II) consists in a plan for upgrading the Fermilab proton accelerator complex to a beam power capability of at least 1 MW delivered to the neutrino production target. A room temperature section accelerates H⁻ ions to 2.1 MeV and creates the desired bunch structure for injection into the superconducting (SC) linac. Five cavity types, operating at three different frequencies 162.5, 325 and 650 MHz, provide acceleration to 800 MeV. This paper presents the studies on transverse field perturbation on particle dynamic for all the superconducting cavities in the linac. The effects studied include quadrupole defocusing for coaxial resonators, and dipole kick due to couplers for elliptical cavities. A multipole expansion has been performed for each of the cavity designs including effects up to octupole.

  2. The Test of LLRF control system on superconducting cavity

    CERN Document Server

    Zhu, Zhenglong; Wen, Lianghua; Chang, Wei; Zhang, Ruifeng; Gao, Zheng; Chen, Qi

    2014-01-01

    The first generation Low-Level radio frequency(LLRF) control system independently developed by IMPCAS, the operating frequency is 162.5MHz for China ADS, which consists of superconducting cavity amplitude stability control, phase stability control and the cavity resonance frequency control. The LLRF control system is based on four samples IQ quadrature demodulation technique consisting an all-digital closed-loop feedback control. This paper completed the first generation of ADS LLRF control system in the low-temperature superconducting cavities LLRF stability and performance online tests. Through testing, to verify the performance of LLRF control system, to analysis on emerging issues, and in accordance with the experimental data, to summarize LLRF control system performance to accumulate experience for the future control of superconducting cavities.

  3. Multiphysics Analysis of Frequency Detuning in Superconducting RF Cavities for Proton Particle Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Awida, M. H. [Fermilab; Gonin, I. [Fermilab; Passarelli, D. [Fermilab; Sukanov, A. [Fermilab; Khabiboulline, T. [Fermilab; Yakovlev, V. [Fermilab

    2016-01-22

    Multiphysics analyses for superconducting cavities are essential in the course of cavity design to meet stringent requirements on cavity frequency detuning. Superconducting RF cavities are the core accelerating elements in modern particle accelerators whether it is proton or electron machine, as they offer extremely high quality factors thus reducing the RF losses per cavity. However, the superior quality factor comes with the challenge of controlling the resonance frequency of the cavity within few tens of hertz bandwidth. In this paper, we investigate how the multiphysics analysis plays a major role in proactively minimizing sources of frequency detuning, specifically; microphonics and Lorentz Force Detuning (LFD) in the stage of RF design of the cavity and mechanical design of the niobium shell and the helium vessel.

  4. Self-formed cavity quantum electrodynamics in coupled dipole cylindrical-waveguide systems.

    Science.gov (United States)

    Afshar V, S; Henderson, M R; Greentree, A D; Gibson, B C; Monro, T M

    2014-05-01

    An ideal optical cavity operates by confining light in all three dimensions. We show that a cylindrical waveguide can provide the longitudinal confinement required to form a two dimensional cavity, described here as a self-formed cavity, by locating a dipole, directed along the waveguide, on the interface of the waveguide. The cavity resonance modes lead to peaks in the radiation of the dipole-waveguide system that have no contribution due to the skew rays that exist in longitudinally invariant waveguides and reduce their Q-factor. Using a theoretical model, we evaluate the Q-factor and modal volume of the cavity formed by a dipole-cylindrical-waveguide system and show that such a cavity allows access to both the strong and weak coupling regimes of cavity quantum electrodynamics.

  5. Cavity-QED entangled photon source based on two truncated Rabi oscillations

    CERN Document Server

    Garcia-Maraver, R; Corbalán, R; Mompart, J

    2006-01-01

    We discuss a cavity-QED scheme to deterministically generate entangled photons pairs by using a three-level atom successively coupled to two single longitudinal mode high-Q cavities presenting polarization degeneracy. The first cavity is prepared in a well defined Fock state with two photons with opposite circular polarizations while the second cavity remains in the vacuum state. A half-of-a-resonant Rabi oscillation in each cavity transfers one photon from the first to the second cavity, leaving the photons entangled in their polarization degree of freedom. The feasibility of this implementation and some practical considerations are discussed for both, microwave and optical regimes. In particular, Monte Carlo wave function simulations have been performed with state-of-the-art parameter values to evaluate the success probability of the cavity-QED source in producing entangled photon pairs as well as its entanglement capability.

  6. Influence of selective atomic measurement on the entanglement properties of a two-atom outside cavity

    Institute of Scientific and Technical Information of China (English)

    Lu Dao-Ming

    2011-01-01

    Considering three two-level atoms initially in the W or Greenberger-Horne-Zeilinger (GHZ) state, one of the three atoms is put into an initially coherent light cavity and made to resonantly interact with the cavity. The two-atom entanglement evolution outside the cavity is investigated. The influences of state-selective measurement of the atom inside the cavity and strength of the light field on the two-atom entanglement evolution outside the cavity are discussed. The results obtained from the numerical method show that the two-atom entanglement outside the cavity is strengthened through state-selective measurement of the atom inside the cavity. In addition, the strength of the light field also influences the two-atom entanglement properties.

  7. Resonant interaction modified by the atomic environment

    Energy Technology Data Exchange (ETDEWEB)

    Sainz, I; Klimov, A B; Chumakov, S M [Departamento de Fisica, Universidad de Guadalajara, Revolucion 1500, 44410, Guadalajara, Jal. (Mexico)

    2003-04-01

    The dynamics of a resonant atom interacting with a quantum cavity field in the presence of many off-resonant atoms is studied. In the framework of the effective Hamiltonian approach we show that the results of elimination of non-resonant transitions are (a) a dynamical Stark shift of the field frequency, dependent on the populations of non-resonant atoms, (b) dependence of the coupling constant between the resonant atom and the field on the populations of non-resonant atoms, and (c) an effective dipole-dipole interaction between non-resonant atoms. Two effects (the coherent influence and dephasing) of the off-resonant environment on the dynamics of the resonant atom are discussed.

  8. Hollow waveguide cavity ringdown spectroscopy

    Science.gov (United States)

    Dreyer, Chris (Inventor); Mungas, Greg S. (Inventor)

    2012-01-01

    Laser light is confined in a hollow waveguide between two highly reflective mirrors. This waveguide cavity is used to conduct Cavity Ringdown Absorption Spectroscopy of loss mechanisms in the cavity including absorption or scattering by gases, liquid, solids, and/or optical elements.

  9. Mechanical properties of niobium radio-frequency cavities

    Energy Technology Data Exchange (ETDEWEB)

    Ciovati, G., E-mail: gciovati@jlab.org [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Dhakal, P.; Matalevich, J.; Myneni, G. [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States); Schmidt, A.; Iversen, J.; Matheisen, A.; Singer, W. [Deutsches Elektronen-Synchrotron, Notkestraße 85, 22607 Hamburg (Germany)

    2015-08-26

    Radio-frequency cavities made of bulk niobium are one of the components used in modern particle accelerators. The mechanical stability is an important aspect of cavity design, which typically relies on finite-element analysis simulations using material properties from tensile tests on sample. This contribution presents the results of strain and resonant frequency measurements as a function of a uniform pressure up to 620 kPa, applied to single-cell niobium cavities with different crystallographic structure, purity and treatments. In addition, burst tests of high-purity multi-cell cavities with different crystallographic structures have been conducted up to the tensile strength of the material. Finite-element analysis of the single-cell cavity geometry is in good agreement with the observed behavior in the elastic regime assuming a Young’s modulus value of 88.5 GPa and a Poisson’s ratio of 0.4, regardless of crystallographic structure, purity or treatment. However, the measured yield strength and tensile strength depend on crystallographic structure, material purity and treatment. In particular, the results from this study show that the mechanical properties of niobium cavities made from ingot material with large crystals are comparable to those of cavities made of fine-grain niobium.

  10. Sensitive Detection of Individual Neutral Atoms in a Strong Coupling Cavity QED System

    Institute of Scientific and Technical Information of China (English)

    ZHANG Peng-Fei; ZHANG Yu-Chi; LI Gang; DU Jin-Jin; ZHANG Yan-Feng; GUO Yan-Qiang; WANG Jun-Min; ZHANG Tian-Cai; LI Wei-Dong

    2011-01-01

    We experimentally demonstrate real-time detection of individual cesium atoms by using a high-finesse optical micro-cavity in a strong coupling regime.A cloud of cesium atoms is trapped in a magneto-optical trap positioned at 5 mm above the micro-cavity center.The atoms fall down freely in gravitation after shutting off the magnetooptical trap and pass through the cavity.The cavity transmission is strongly affected by the atoms in the cavity, which enables the micro-cavity to sense the atoms individually.We detect the single atom transits either in the resonance or various detunings.The single atom vacuum-Rabi splitting is directly measured to be Ω = 2π × 23.9 MHz.The average duration of atom-cavity coupling of about 110μs is obtained according to the probability distribution of the atom transits.%@@ We experimentally demonstrate real-time detection of individual cesium atoms by using a high-finesse optical micro-cavity in a strong coupling regime.A cloud of cesium atoms is trapped in a magneto-optical trap positioned at 5mm above the micro-cavity center.The atoms fall down freely in gravitation after shutting off the magnetooptical trap and pass through the cavity.The cavity transmission is strongly affected by the atoms in the cavity, which enables the micro-cavity to sense the atoms individually.We detect the single atom transits either in the resonance or various detunings.The single atom vacuum-Rabi splitting is directly measured to be Ω=2π×23.9 MHz.The average duration of atom-cavity coupling of about 110μs is obtained according to the probability distribution of the atom transits.

  11. Colloquium: cavity optomechanics

    CERN Multimedia

    2011-01-01

    Monday 14 November 2011, 17:00 Ecole de Physique, Auditoire Stueckelberg Université de Genève Cavity optomechanics: controlling micro mechanical oscillators with laser light Prof. Tobias Kippenberg EPFL, Lausanne Laser light can be used to cool and to control trapped ions, atoms and molecules at the quantum level. This has lead to spectacular advances such as the most precise atomic clocks. An outstanding frontier is the control with lasers of nano- and micro-mechancial systems. Recent advances in cavity optomechanics have allowed such elementary control for the first time, enabling mechanical systems to be ground state cooled leading to readout with quantum limited sensitivity and permitting to explore new device concepts resulting from radiation pressure.  

  12. Access cavity preparation.

    Science.gov (United States)

    Adams, N; Tomson, P L

    2014-03-01

    Each stage of root canal treatment should be carried out to the highest possible standard. The access cavity is arguably the most important technical stage, as subsequent preparation of the root canal(s) can be severely comprised if this is not well executed. Inadequate access can lead to canals being left untreated, poorly disinfected, difficult to shape and obturate, and may ultimately lead to the failure of the treatment. This paper highlights common features in root canal anatomy and outlines basic principles for locating root canals and producing a good access cavity. It also explores each phase of the preparation in detail and offers suggestions of instruments that have been specifically designed to overcome potential difficulties in the process. Good access design and preparation will result in an operative environment which will facilitate cleaning, shaping and obturation of the root canal system in order to maximise success.

  13. Cavity enhanced atomic magnetometry

    CERN Document Server

    Crepaz, Herbert; Dumke, Rainer

    2015-01-01

    Atom sensing based on Faraday rotation is an indispensable method for precision measurements, universally suitable for both hot and cold atomic systems. Here we demonstrate an all-optical magnetometer where the optical cell for Faraday rotation spectroscopy is augmented with a low finesse cavity. Unlike in previous experiments, where specifically designed multipass cells had been employed, our scheme allows to use conventional, spherical vapour cells. Spherical shaped cells have the advantage that they can be effectively coated inside with a spin relaxation suppressing layer providing long spin coherence times without addition of a buffer gas. Cavity enhancement shows in an increase in optical polarization rotation and sensitivity compared to single-pass configurations.

  14. Cavity enhanced atomic magnetometry.

    Science.gov (United States)

    Crepaz, Herbert; Ley, Li Yuan; Dumke, Rainer

    2015-10-20

    Atom sensing based on Faraday rotation is an indispensable method for precision measurements, universally suitable for both hot and cold atomic systems. Here we demonstrate an all-optical magnetometer where the optical cell for Faraday rotation spectroscopy is augmented with a low finesse cavity. Unlike in previous experiments, where specifically designed multipass cells had been employed, our scheme allows to use conventional, spherical vapour cells. Spherical shaped cells have the advantage that they can be effectively coated inside with a spin relaxation suppressing layer providing long spin coherence times without addition of a buffer gas. Cavity enhancement shows in an increase in optical polarization rotation and sensitivity compared to single-pass configurations.

  15. Cavity cooling of an ensemble spin system.

    Science.gov (United States)

    Wood, Christopher J; Borneman, Troy W; Cory, David G

    2014-02-07

    We describe how sideband cooling techniques may be applied to large spin ensembles in magnetic resonance. Using the Tavis-Cummings model in the presence of a Rabi drive, we solve a Markovian master equation describing the joint spin-cavity dynamics to derive cooling rates as a function of ensemble size. Our calculations indicate that the coupled angular momentum subspaces of a spin ensemble containing roughly 10(11) electron spins may be polarized in a time many orders of magnitude shorter than the typical thermal relaxation time. The described techniques should permit efficient removal of entropy for spin-based quantum information processors and fast polarization of spin samples. The proposed application of a standard technique in quantum optics to magnetic resonance also serves to reinforce the connection between the two fields, which has recently begun to be explored in further detail due to the development of hybrid designs for manufacturing noise-resilient quantum devices.

  16. Cavity-Enhanced Ultrafast Transient Absorption Spectroscopy

    CERN Document Server

    Reber, Melanie A R; Allison, Thomas K

    2015-01-01

    We present a new technique using a frequency comb laser and optical cavities for performing ultrafast transient absorption spectroscopy with improved sensitivity. Resonantly enhancing the probe pulses, we demonstrate a sensitivity of $\\Delta$OD $ = 1 \\times 10^{-9}/\\sqrt{\\mbox{Hz}}$ for averaging times as long as 30 s per delay point ($\\Delta$OD$_{min} = 2 \\times 10^{-10}$). Resonantly enhancing the pump pulses allows us to produce a high excitation fraction at high repetition-rate, so that signals can be recorded from samples with optical densities as low as OD $\\approx 10^{-8}$, or column densities $< 10^{10}$ molecules/cm$^2$. This high sensitivity enables new directions for ultrafast spectroscopy.

  17. Single atoms on demand for cavity QED experiments

    Energy Technology Data Exchange (ETDEWEB)

    Dotsenko, I.

    2007-09-06

    Cavity quantum electrodynamics (cavity QED) describes electromagnetic fields in a confined space and the radiative properties of atoms in such fields. The simplest example of such system is a single atom interacting with one mode of a high-finesse resonator. Besides observation and exploration of fundamental quantum mechanical effects, this system bears a high potential for applications quantum information science such as, e.g., quantum logic gates, quantum communication and quantum teleportation. In this thesis I present an experiment on the deterministic coupling of a single neutral atom to the mode of a high-finesse optical resonator. In Chapter 1 I describe our basic techniques for trapping and observing single cesium atoms. As a source of single atoms we use a high-gradient magneto-optical trap, which captures the atoms from background gas in a vacuum chamber and cools them down to millikelvin temperatures. The atoms are then transferred without loss into a standing-wave dipole trap, which provides a conservative potential required for experiments on atomic coherence such as quantum information processing and metrology on trapped atoms. Moreover, shifting the standing-wave pattern allows us to deterministically transport the atoms (Chapter 2). In combination with nondestructive fluorescence imaging of individual trapped atoms, this enables us to control their position with submicrometer precision over several millimeters along the dipole trap. The cavity QED system can distinctly display quantum behaviour in the so-called strong coupling regime, i.e., when the coherent atom-cavity coupling rate dominates dissipation in the system. This sets the main requirements on the resonator's properties: small mode volume and high finesse. Chapter 3 is devoted to the manufacturing, assembling, and testing of an ultra-high finesse optical Fabry-Perot resonator, stabilized to the atomic transition. In Chapter 4 I present the transportation of single atoms into the

  18. Cryogenic resonant microwave compressors with energy extraction through "warm" interference switches

    Science.gov (United States)

    Artemenko, S. N.; Samoilenko, G. M.; Shlapakovski, A. S.; Yushkov, Yu. G.

    2016-01-01

    A method of switching cryogenic resonant microwave compressors from the energy accumulation mode to the energy release mode is proposed and analyzed. The switching process is based on the resonant transfer of the microwave energy from a cryogenic storage cavity to a room temperature commutation cavity. The transfer can be realized using a cascade interference microwave switch weakly coupled to the storage cavity and consisting of two H-plane waveguide tees connected in series. The tees are made of a normally conducting material, located outside the cryostat, and contain commuting units in shorted side arms. The length of the cascade input arm (from the storage cavity to the first tee) is non-resonant, while the space between the storage cavity and the second tee is resonant. The weak coupling of the storage cavity to the cascade and the non-resonant length of its input arm allow one to minimize losses during the energy accumulation phase. When the commuting unit in the first tee is ignited, the tee opens, and the non-resonant volume of the cascade input arm is transformed into the volume of the resonant commutation cavity. The microwave energy is then transferred in a resonant way from the storage cavity to the commutation cavity, and when the transfer is complete, the commuting unit in the second tee is ignited to extract the energy into a load. It is shown analytically that, at a certain value of the coupling (the cryogenic storage cavity to the normally conducting cascade of tees) and length of the cascade input arm, the power gain in the storage cavity can be kept high. It is also shown that the energy accumulated in the storage cavity can be effectively transferred to the commutation cavity and from the commutation cavity to the load.

  19. Cavity enhanced atomic magnetometry

    OpenAIRE

    Herbert Crepaz; Li Yuan Ley; Rainer Dumke

    2015-01-01

    Atom sensing based on Faraday rotation is an indispensable method for precision measurements, universally suitable for both hot and cold atomic systems. Here we demonstrate an all-optical magnetometer where the optical cell for Faraday rotation spectroscopy is augmented with a low finesse cavity. Unlike in previous experiments, where specifically designed multipass cells had been employed, our scheme allows to use conventional, spherical vapour cells. Spherical shaped cells have the advantage...

  20. Generalized cavity model and nonlocal effects in nanoslit arrays

    CERN Document Server

    Dechaux, Mathieu; Ciracì, Cristian; Benedicto, Jessica; Pollès, Rémi; Centeno, Emmanuel; Smith, David R; Moreau, Antoine

    2016-01-01

    Gap-plasmon resonators are a class of nanogap-based plasmonic structures presenting unprecedented optical properties despite a size that can be smaller than the skin depth of metals. In the case of extremely narrow slit arrays, these ultra-small resonators are better described by a generalized cavity model. Moreover, such structures are sensitive to the nonlocal response of the metals arising from interactions between free electrons inside the jellium. This phenomenon actually influences the necessarily intense plasmonic slowdown (very low phase and group velocities) experienced by the gap-plasmon in such tiny cavities. Accurately describing the optical response of this class of structures requires to take all of these effects into account, and will undoubtedly be necessary to design or characterize future gap-plasmon resonators.

  1. Multimode Strong Coupling in Superconducting Cavity Piezo-electromechanics

    CERN Document Server

    Han, Xu; Tang, Hong X

    2016-01-01

    High frequency mechanical resonators subjected to low thermal phonon occupancy are easier to be prepared to the ground state by direct cryogenic cooling. Their extreme stiffness, however, poses a significant challenge for external interrogations. Here we demonstrate a superconducting cavity piezo-electromechanical system in which multiple modes of a bulk acoustic resonator oscillating at $10\\,\\textrm{GHz}$ are coupled to a planar microwave superconducting resonator with a cooperativity exceeding $2\\times10^{3}$, deep in the strong coupling regime. By implementation of the non-contact coupling scheme to reduce mechanical dissipation, the system exhibits excellent coherence characterized by a frequency-quality factor product of $7.5\\times10^{15}\\,\\textrm{Hz}$. Interesting dynamics of temporal oscillations of the microwave energy is observed, implying the coherent conversion between phonons and photons. The demonstrated high frequency cavity piezo-electromechanics is compatible with superconducting qubits, repre...

  2. Toroid cavity/coil NMR multi-detector

    Science.gov (United States)

    Gerald, II, Rex E.; Meadows, Alexander D.; Gregar, Joseph S.; Rathke, Jerome W.

    2007-09-18

    An analytical device for rapid, non-invasive nuclear magnetic resonance (NMR) spectroscopy of multiple samples using a single spectrometer is provided. A modified toroid cavity/coil detector (TCD), and methods for conducting the simultaneous acquisition of NMR data for multiple samples including a protocol for testing NMR multi-detectors are provided. One embodiment includes a plurality of LC resonant circuits including spatially separated toroid coil inductors, each toroid coil inductor enveloping its corresponding sample volume, and tuned to resonate at a predefined frequency using a variable capacitor. The toroid coil is formed into a loop, where both ends of the toroid coil are brought into coincidence. Another embodiment includes multiple micro Helmholtz coils arranged on a circular perimeter concentric with a central conductor of the toroid cavity.

  3. Cavity QED by the Numbers

    Science.gov (United States)

    Kimble, H. J.; Boca, A.; Boozer, A. D.; Bowen, W. P.; Buck, J. R.; Chou, C. W.; Duan, L.-M.; Kuzmich, A.; McKeever, J.

    2004-12-01

    Observations of cooling and trapping of N = 1,2,3,... atoms inside a small optical cavity are described. The atom-cavity system operates in a regime of strong coupling for which single photons are sufficient to saturate the atomic response. New theoretical protocols for the efficient engineering of multi-atom entanglement within the setting of cavity QED are described. By trapping a single atom within the cavity mode, a one-atom laser is experimentally realized in a regime of strong coupling. Beyond the setting of cavity QED, quantum correlations have been observed for photon pairs emitted from an atomic ensemble and with a programmable time offset.

  4. The influence of an external cavity on the emission spectrum of a mercury germicidal lamp

    Science.gov (United States)

    Solomonov, V. I.; Surkov, Yu. S.; Gorbunkov, V. I.

    2016-09-01

    The spectrum of emission from the cylindrical duralumin cavity of a TUV 8wG8 T5 UV industrial germicidal mercury lamp is studied. It is shown that, due to reflection from the inner surface of the cavity and reabsorption in the gas discharge, the resonance line of a mercury atom is significantly weakened. The dependence of the resonance line intensity on the discharge current has a maximum, and the discharge current corresponding to the intensity maximum depends on the reflection coefficient of the inner surface of the cavity.

  5. Two-photon gateway in one-atom cavity quantum electrodynamics

    OpenAIRE

    2008-01-01

    Single atoms absorb and emit light from a resonant laser beam photon by photon. We show that a single atom strongly coupled to an optical cavity can absorb and emit resonant photons in pairs. The effect is observed in a photon correlation experiment on the light transmitted through the cavity. We find that the atom-cavity system transforms a random stream of input photons into a correlated stream of output photons, thereby acting as a two-photon gateway. The phenomenon has its origin in the q...

  6. Crab Cavities for Linear Colliders

    Energy Technology Data Exchange (ETDEWEB)

    Burt, G.; Ambattu, P.; Carter, R.; Dexter, A.; Tahir, I.; /Cockcroft Inst. Accel. Sci. Tech. /Lancaster U.; Beard, C.; Dykes, M.; Goudket, P.; Kalinin, A.; Ma, L.; McIntosh, P.; /Daresbury; Shulte, D.; /CERN; Jones, Roger M.; /Cockcroft Inst. Accel. Sci. Tech. /Manchester U.; Bellantoni, L.; Chase, B.; Church, M.; Khabouline, T.; Latina, A.; /Fermilab; Adolphsen, C.; Li, Z.; Seryi, Andrei; /SLAC

    2011-11-08

    Crab cavities have been proposed for a wide number of accelerators and interest in crab cavities has recently increased after the successful operation of a pair of crab cavities in KEK-B. In particular crab cavities are required for both the ILC and CLIC linear colliders for bunch alignment. Consideration of bunch structure and size constraints favour a 3.9 GHz superconducting, multi-cell cavity as the solution for ILC, whilst bunch structure and beam-loading considerations suggest an X-band copper travelling wave structure for CLIC. These two cavity solutions are very different in design but share complex design issues. Phase stabilisation, beam loading, wakefields and mode damping are fundamental issues for these crab cavities. Requirements and potential design solutions will be discussed for both colliders.

  7. Crab cavities for linear colliders

    CERN Document Server

    Burt, G; Carter, R; Dexter, A; Tahir, I; Beard, C; Dykes, M; Goudket, P; Kalinin, A; Ma, L; McIntosh, P; Shulte, D; Jones, Roger M; Bellantoni, L; Chase, B; Church, M; Khabouline, T; Latina, A; Adolphsen, C; Li, Z; Seryi, Andrei; Xiao, L

    2008-01-01

    Crab cavities have been proposed for a wide number of accelerators and interest in crab cavities has recently increased after the successful operation of a pair of crab cavities in KEK-B. In particular crab cavities are required for both the ILC and CLIC linear colliders for bunch alignment. Consideration of bunch structure and size constraints favour a 3.9 GHz superconducting, multi-cell cavity as the solution for ILC, whilst bunch structure and beam-loading considerations suggest an X-band copper travelling wave structure for CLIC. These two cavity solutions are very different in design but share complex design issues. Phase stabilisation, beam loading, wakefields and mode damping are fundamental issues for these crab cavities. Requirements and potential design solutions will be discussed for both colliders.

  8. Inverse-problem approach to designing photonic crystals for cavity QED experiments.

    Science.gov (United States)

    Geremia, J M; Williams, Jon; Mabuchi, Hideo

    2002-12-01

    Photonic band gap (PBG) materials are attractive for cavity QED experiments because they provide extremely small mode volumes and are monolithic, integratable structures. As such, PBG cavities are a promising alternative to Fabry-Perot resonators. However, the cavity requirements imposed by QED experiments, such as the need for high Q (low cavity damping) and small mode volumes, present significant design challenges for photonic band gap materials. Here, we pose the PBG design problem as a mathematical inversion and provide an analytical solution for a two-dimensional (2D) crystal. We then address a planar (2D crystal with finite thickness) structure using numerical techniques.

  9. Interference control of nonlinear excitation in a multi-atom cavity quantum electrodynamics system.

    Science.gov (United States)

    Yang, Guoqing; Tan, Zheng; Zou, Bichen; Zhu, Yifu

    2014-12-01

    We show that by manipulating quantum interference in a multi-atom cavity quantum electrodynamics (CQED) system, the nonlinear excitation of the cavity-atom polariton can be resonantly enhanced while the linear excitation is suppressed. Under the appropriate conditions, it is possible to selectively enhance or suppress the polariton excitation with two free-pace laser fields. We report on an experiment with cold Rb atoms in an optical cavity and present experimental results that demonstrate such interference control of the CQED excitation and its direct application to studies of all-optical switching and cross-phase modulation of the cavity-transmitted light.

  10. Imaging Finding of Malignant Melanoma of Eustachian Tube with Extension to Middle Ear Cavity: Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Km Hong Chul [Dept. of Radiology, Yeungnam University College of Medicine, Daegu (Korea, Republic of); Jang, Han Won [Daekyung Radiologic Clinics, Daegu (Korea, Republic of); Lee, Hui Joong [Dept. of Radiology, Kyungpook National University Hospital, Daegu (Korea, Republic of)

    2012-11-15

    We report a case of malignant melanoma of Eustachian tube with extension to the middle ear cavity and nasopharynx in a 51-year-old woman who presented with right ear fullness. Computed tomography showed a soft tissue mass in the middle ear cavity and caused the widening and eroding of the bony eustachian tube. Magnetic resonance imaging showed well enhancing mass in eustachian tube extending nasopharynx to middle ear cavity. A biopsy of the middle ear cavity mass revealed a malignant amelanotic melanoma.

  11. Imaging Finding of Malignant Melanoma of Eustachian Tube with Extension to Middle Ear Cavity: Case Report

    Science.gov (United States)

    Kim, Hong Chul; Jang, Han Won

    2012-01-01

    We report a case of malignant melanoma of Eustachian tube with extension to the middle ear cavity and nasopharynx in a 51-year-old woman who presented with right ear fullness. Computed tomography showed a soft tissue mass in the middle ear cavity and causedthe widening and eroding of the bony eustachian tube. Magnetic resonance imaging showed well enhancing mass in eustachian tube extending nasopharynx to middle ear cavity. A biopsy of the middle ear cavity mass revealed a malignant amelanotic melanoma. PMID:23118582

  12. 利用V型三能级原子与单模光场的非共振相互作用制备压缩相干态的叠加态%Generation of Superpositions of Squeezed Coherent States through Non-resonant Interaction of Degenerate V-type Three-level Atoms with Single-mode Cavity Field

    Institute of Scientific and Technical Information of China (English)

    戴宏毅; 李承祖; 陈平形; 梁林梅

    2003-01-01

    介绍了单模压缩相干态及其基本性质,根据简并V型三能级原子与单模光场的改进型有效哈密顿量,通过矩阵方法推导出原子-光场系统的态矢量.提出利用简并V型三能级原子与单模光场的非共振相互作用制备压缩相干态的叠加态的一种新方案,讨论了怎样进行控制单模压缩相干态光场中的压缩方向问题.%The single-mode squeezed coherent states and their fundamental properties are discussed. Based on the modified effective Hamiltonian for the atom-field system, the state of the system is derived by means of matrix. A new scheme is presented to generate superposition of squeezed coherent states through non-resonant of degenerate V-type three-level atoms with single-mode cavity field. Controls of the squeezing direction of single-mode squeezed coherent states in the light field are also discussed.

  13. Flat sources for active acoustic shielding based on distributed control of a vibrating plate coupled with a thin cavity

    NARCIS (Netherlands)

    Berkhoff, A.P.; Ho, J.H.

    2013-01-01

    Air cavities between plates are often used to improve noise insulation by passive means, especially at high frequencies. Such configurations may suffer from resonances, such as due to the mass-air-mass resonance. Lightweight structures, which tend to be undamped, may suffer from structural resonance

  14. Boundary-Layer Effects on Acoustic Transmission Through Narrow Slit Cavities

    Science.gov (United States)

    Ward, G. P.; Lovelock, R. K.; Murray, A. R. J.; Hibbins, A. P.; Sambles, J. R.; Smith, J. D.

    2015-07-01

    We explore the slit-width dependence of the resonant transmission of sound in air through both a slit array formed of aluminum slats and a single open-ended slit cavity in an aluminum plate. Our experimental results accord well with Lord Rayleigh's theory concerning how thin viscous and thermal boundary layers at a slit's walls affect the acoustic wave across the whole slit cavity. By measuring accurately the frequencies of the Fabry-Perot-like cavity resonances, we find a significant 5% reduction in the effective speed of sound through the slits when an individual viscous boundary layer occupies only 5% of the total slit width. Importantly, this effect is true for any airborne slit cavity, with the reduction being achieved despite the slit width being on a far larger scale than an individual boundary layer's thickness. This work demonstrates that the recent prevalent loss-free treatment of narrow slit cavities within acoustic metamaterials is unrealistic.

  15. Cavity Cooling for Ensemble Spin Systems

    Science.gov (United States)

    Cory, David

    2015-03-01

    Recently there has been a surge of interest in exploring thermodynamics in quantum systems where dissipative effects can be exploited to perform useful work. One such example is quantum state engineering where a quantum state of high purity may be prepared by dissipative coupling through a cold thermal bath. This has been used to great effect in many quantum systems where cavity cooling has been used to cool mechanical modes to their quantum ground state through coupling to the resolved sidebands of a high-Q resonator. In this talk we explore how these techniques may be applied to an ensemble spin system. This is an attractive process as it potentially allows for parallel remove of entropy from a large number of quantum systems, enabling an ensemble to achieve a polarization greater than thermal equilibrium, and potentially on a time scale much shorter than thermal relaxation processes. This is achieved by the coupled angular momentum subspaces of the ensemble behaving as larger effective spins, overcoming the weak individual coupling of individual spins to a microwave resonator. Cavity cooling is shown to cool each of these subspaces to their respective ground state, however an additional algorithmic step or dissipative process is required to couple between these subspaces and enable cooling to the full ground state of the joint system.

  16. Numerical Investigation of Vertical Cavity Lasers with Subwavelength Gratings Using the Fourier Modal Method

    CERN Document Server

    Taghizadeh, Alireza; Chung, Il-Sug

    2016-01-01

    We show the strength of the Fourier modal method (FMM) for numerically investigating the optical properties of vertical cavities including subwavelength gratings. Three different techniques for determining the resonance frequency and Q-factor of a cavity mode are compared. Based on that, the Fabry-Perot approach has been chosen due to its numerical efficiency. The computational uncertainty in determining the resonance frequency and Q-factor is investigated, showing that the uncertainty in the Q-factor calculation can be a few orders of magnitude larger than that in the resonance frequency calculation. Moreover, a method for reducing 3D simulations to lower-dimensional simulations is suggested, and is shown to enable approximate and fast simulations of certain device parameters. Numerical calculation of the cavity dispersion, which is an important characteristic of vertical cavities, is illustrated. By employing the implemented FMM, it is shown that adiabatic heterostructures designs are advantageous compared ...

  17. Super-Resonant Intracavity Coherent Absorption

    CERN Document Server

    Malara, P; Giorgini, A; Avino, S; De Natale, P; Gagliardi, G

    2016-01-01

    The capability of optical resonators to extend the effective radiation-matter interaction length originates from a multipass effect, hence is intrinsically limited by the resonator quality factor. Here, we show that this constraint can be overcome by combining the concepts of resonant interaction and coherent perfect absorption. We demonstrate and investigate super-resonant coherent absorption in a coupled Fabry-Perot-ring cavity structure. At the FP resonant wavelengths, the described phenomenon gives rise to split modes with a nearly-transparent peak and a peak whose transmission is exceptionally sensitive to the intracavity loss. For small losses, the effective interaction pathlength of these modes is proportional respectively to the ratio and the product of the individual finesse coefficients of the two resonators. The results presented extend the conventional definition of resonant absorption and point to a way of circumventing the technological limitations of ultrahigh-quality resonators in spectroscopy...

  18. Optical resonance of metal-coated nanoshell

    Institute of Scientific and Technical Information of China (English)

    Diao Jia-Jie(刁佳杰); Chen Guang-De(陈光德); Xi Cong(席聪); Z Y Fan; Yuan Jin-She(苑进社)

    2003-01-01

    Metal-coated nanoshell, the nanoparticle consisting of a nanometre-scale dielectric core coated with a thin metallic shell, exhibits three distinct optical resonant forms, the sphere cavity resonance (SCR), plasmon resonance (PR), and concentric dielectric sphere resonance (CDSR). The SCR, PR and CDSR of the metal-coated nanoshell reveal a geometric tunability controlled by the core radius and by the ratio of the core radius to the total radius. Classical electrodynamics and Mie scattering theory are used to treat the resonant forms and the transition state between the resonant forms. Based on previous experimental research, we present a group of resonant equations for all the resonant forms, which depend on the geometric structure of the metal-coated nanoshell.

  19. An improved equivalent circuit model of a four rod deflecting cavity

    Science.gov (United States)

    Apsimon, R.; Burt, G.

    2017-03-01

    In this paper we present an improved equivalent circuit model for a four rod deflecting cavity which calculates the frequencies of the first four modes of the cavity as well as the RT/Q for the deflecting mode. Equivalent circuit models of RF cavities give intuition and understanding about how the cavity operates and what changes can be made to modify the frequency, without the need for RF simulations, which can be time-consuming. We parameterise a generic four rod deflecting cavity into a geometry consisting of simple shapes. Equations are derived for the line impedance of the rods and the capacitance between the rods and these are used to calculate the resonant frequency of the deflecting dipole mode as well as the lower order mode and the model is bench-marked against two test cases; the CEBAF separator and the HL-LHC 4-rod LHC crab cavity. CST and the equivalent circuit model agree within 4% for both cavities with the LOM frequency and within 1% for the deflecting frequency. RT/Q differs between the model and CST by 37% for the CEBAF separator and 25% for the HL-LHC 4-rod crab cavity; however this is sufficient for understanding how to optimise the cavity design. The model has then been utilised to suggest a method of separating the modal frequencies in the HL-LHC crab cavity and to suggest design methodologies to optimise the cavity geometries.

  20. Purcell effect in Hyperbolic Metamaterial Resonators

    CERN Document Server

    Slobozhanyuk, Alexey P; Powell, David A; Iorsh, Ivan; Shalin, Alexander S; Segovia, Paulina; Krasavin, Alexey V; Wurtz, Gregory A; Podolskiy, Viktor A; Belov, Pavel A; Zayats, Anatoly V

    2015-01-01

    The radiation dynamics of optical emitters can be manipulated by properly designed material structures providing high local density of photonic states, a phenomenon often referred to as the Purcell effect. Plasmonic nanorod metamaterials with hyperbolic dispersion of electromagnetic modes are believed to deliver a significant Purcell enhancement with both broadband and non-resonant nature. Here, we have investigated finite-size cavities formed by nanorod metamaterials and shown that the main mechanism of the Purcell effect in these hyperbolic resonators originates from the cavity hyperbolic modes, which in a microscopic description stem from the interacting cylindrical surface plasmon modes of the finite number of nanorods forming the cavity. It is found that emitters polarized perpendicular to the nanorods exhibit strong decay rate enhancement, which is predominantly influenced by the rod length. We demonstrate that this enhancement originates from Fabry-Perot modes of the metamaterial cavity. The Purcell fa...

  1. Stimulated Cavity-Optomechanics

    CERN Document Server

    Bahl, Gaurav; Tomes, Matthew; Carmon, Tal

    2011-01-01

    Stimulated Brillouin interaction between sound and light, known to be the strongest optical nonlinearity common to all amorphous and crystalline dielectrics, has been widely studied in fibers and bulk materials but rarely in optical microresonators. The possibility of experimentally extending this principle to excite mechanical resonances in photonic microsystems, for sensing and frequency reference applications, has remained largely unexplored. The challenge lies in the fact that microresonators inherently have large free spectral range, while the phase matching considerations for the Brillouin process require optical modes of nearby frequencies but with different wavevectors. We rely on high-order transverse optical modes to relax this limitation. Here we report on the experimental excitation of mechanical resonances ranging from 49 to 1400 MHz by using forward Brillouin scattering. These natural mechanical resonances are excited in ~100 um silica microspheres, and are of a surface-acoustic whispering-galle...

  2. Determination of the dipole moment of OCS with a microwave absorption cavity

    NARCIS (Netherlands)

    Dijkerman, H.A.; Ruitenberg, G.

    1969-01-01

    The electric dipole moment of OCS has been measured with a resonance cavity as a Stark absorption cell. The result: μOCS = 0.7149 ± 0.0003. Debye agrees well with the dipole moment data obtained with an electric resonance beam experiment.

  3. ISR RF cavities

    CERN Multimedia

    1983-01-01

    In each ISR ring the radiofrequency cavities were installed in one 9 m long straight section. The RF system of the ISR had the main purpose to stack buckets of particles (most of the time protons)coming from the CPS and also to accelerate the stacked beam. The installed RF power per ring was 18 kW giving a peak accelerating voltage of 20 kV. The system had a very fine regulation feature allowing to lower the voltage down to 75 V in a smooth and well controlled fashion.

  4. A Monolithic Filter Cavity for Experiments in Quantum Optics

    CERN Document Server

    Palittapongarnpim, Pantita; Lvovsky, A I

    2012-01-01

    By applying a high-reflectivity dielectric coating on both sides of a commercial plano-convex lens, we produce a stable monolithic Fabry-Perot cavity suitable for use as a narrow band filter in quantum optics experiments. The resonant frequency is selected by means of thermal expansion. Owing to the long term mechanical stability, no optical locking techniques are required. We characterize the cavity performance as an optical filter, obtaining a 45 dB suppression of unwanted modes while maintaining a transmission of 60%.

  5. RF Characterization of Niobium Films for Superconducting Cavities

    CERN Document Server

    Aull† , S; Doebert, S; Junginger, T; Ehiasarian, AP; Knobloch, J; Terenziani, G

    2013-01-01

    The surface resistance RS of superconductors shows a complex dependence on the external parameters such as temperature, frequency or radio-frequency (RF) field. The Quadrupole Resonator modes of 400, 800 and 1200 MHz allow measurements at actual operating frequencies of superconducting cavities. Niobium films on copper substrates have several advantages over bulk niobium cavities. HIPIMS (High-power impulse magnetron sputtering) is a promising technique to increase the quality and therefore the performance of niobium films. This contribution will introduce CERNs recently developed HIPIMS coating apparatus. Moreover, first results of niobium coated copper samples will be presented, revealing the dominant loss mechanisms.

  6. Fluidic vortices generated from optical vortices in a microdroplet cavity

    CERN Document Server

    Bar-David, Daniel; Martin, Leoplodo L; Carmon, Tal

    2016-01-01

    We harness the momentum of light resonating inside a micro-droplet cavity, to experimentally generate micro-flows within the envelope of the drop. We 3D map these optically induced flows by using fluorescent nanoparticles; which reveals circular micro-streams. The flows are parametrically studied and, as expected, exhibit an increase of rotation speed with optical power. The flow is non-circular only when we intentionally break the axial symmetry of the droplet. Besides the fundamental interest in light-flow interactions including in opto-fluidic cavities, the optically controlled flows can serve in bringing analytes into the maximum-power region of the microcavity.

  7. CAVITY BEAM POSITION MONITOR SYSTEM FOR ATF2

    CERN Document Server

    Boogert, S T; Cullinan, F; Joshi, N; Lyapin, A; Aryshev, A; Honda, Y; Naito, T; Terunuma, N; Urakara, J; Heo, A; Kim, E-S; Kim, Y I; McCormick, D; Frisch, J; Nelson, J; Smith, T; White, G R

    2011-01-01

    The Accelerator Test Facility 2 (ATF2) in KEK, Japan, is a prototype scaled demonstrator system for the final focus required for a future high energy lepton linear collider. The ATF2 beam-line is instrumented with a total of 41 high resolution C and S band resonant cavity beam position monitors (BPM) with associated mixer electronics and digitisers. In addition 4 high resolution BPMs have been recently installed at the interaction point, we briefly describe the first operational experience of these cavities in the ATF2 beam-line. The current status of the overall BPM system is also described, with a focus on operational techniques and performance.

  8. Cavity QED based tuneable, delayed-choice quantum eraser

    Science.gov (United States)

    Imran, Muhammad; Abbas, Tasawar; -ul-Islam, Rameez; Ikram, Manzoor

    2016-01-01

    We propose an experimentally feasible idea for the delayed-choice quantum eraser, having adjustable path distinguishability/fringe visibility. The schematics are based on resonant, dispersive and Ramsey interactions of atoms under cavity QED scenario. The option for tuneability of the fringes in a delayed-choice setup stringently marks the conception of the time in the quantum theory, operational meanings of the state vector reduction and raises questions about Ψ-ontic models while helping to shed out the controversies surrounding the quantum eraser theme. The proposal can be efficiently executed experimentally within the prevailing cavity QED experimental research scenario with good overall success probability and fidelity.

  9. Negative differential resistance in Josephson junctions coupled to a cavity

    DEFF Research Database (Denmark)

    Pedersen, Niels Falsig; Filatrella, G.; Pierro, V.

    2014-01-01

    or external – is often used. A cavity may also induce a negative differential resistance region at the lower side of the resonance frequency. We investigate the dynamics of Josephson junctions with a negative differential resistance in the quasi particle tunnel current, i.e. in the McCumber curve. We find......Regions with negative differential resistance can arise in the IV curve of Josephson junctions and this phenomenon plays an essential role for applications, in particular for THz radiation emission. For the measurement of high frequency radiation from Josephson junctions, a cavity – either internal...

  10. Performance of a dual Fabry-Perot cavity refractometer.

    Science.gov (United States)

    Egan, Patrick F; Stone, Jack A; Hendricks, Jay H; Ricker, Jacob E; Scace, Gregory E; Strouse, Gregory F

    2015-09-01

    We have built and characterized a refractometer that utilizes two Fabry-Perot cavities formed on a dimensionally stable spacer. In the typical mode of operation, one cavity is held at vacuum, and the other cavity is filled with nitrogen gas. The differential change in length between the cavities is measured as the difference in frequency between two helium-neon lasers, one locked to the resonance of each cavity. This differential change in optical length is a measure of the gas refractivity. Using the known values for the molar refractivity and virial coefficients of nitrogen, and accounting for cavity length distortions, the device can be used as a high-resolution, multi-decade pressure sensor. We define a reference value for nitrogen refractivity as n-1=(26485.28±0.3)×10(-8) at p=100.0000  kPa, T=302.9190  K, and λ(vac)=632.9908  nm. We compare pressure determinations via the refractometer and the reference value to a mercury manometer.

  11. An RF input coupler for a superconducting single cell cavity

    Energy Technology Data Exchange (ETDEWEB)

    Fechner, B.; Ouchi, Nobuo; Kusano, Joichi; Mizumoto, Motoharu; Mukugi, Ken [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Krawczyk, F.

    1999-03-01

    Japan Atomic Energy Research Institute proposes a high intensity proton accelerator for the Neutron Science Project. A superconducting linac is a main option for the high energy part of the accelerator. Design and development work for the superconducting accelerating cavities (resonant frequency of 600 MHz) is in progress. Superconducting cavities have an advantage of very high accelerating efficiency because RF wall loss is very small and much of the RF power fed to the cavity is consumed for the beam acceleration. On the other hand, an RF input coupler for the superconducting cavity has to be matched to the beam loading. Therefore, estimation of coupling coefficient or external quality factor (Qext) of the RF input coupler is important for the design of the couplers. In this work, Qext`s were calculated by the electromagnetic analysis code (MAFIA) and were compared with those by the measurements. A {beta} (ratio of the particle velocity to the light velocity) = 0.5 single-cell cavity with either axial coupler or side coupler was used in this work. In the experiments, a model cavity made by copper is applied. Both 2- and 3-dimensional calculations were performed in the axial coupler geometry and the results were compared. The agreements between calculated and measured values are good and this method for calculation of Qext is confirmed to be proper for the design of the RF input couplers. (author)

  12. Molecular-Resonance Fiber Optic Gas Sensors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Aspen systems proposes to develop an innovative and smart sensors to continuously monitor ambient air compositions by utilizing a resonating tunable micro-cavity...

  13. Cavity as a source of conformational fluctuation and high-energy state: High-pressure NMR study of a cavity-enlarged mutant of T4 lysozyme

    CERN Document Server

    Maeno, Akihiro; Hirata, Fumio; Otten, Renee; Dahlquist, Frederick W; Yokoyama, Shigeyuki; Akasaka, Kazuyuki; Mulder, Frans A A; Kitahara, Ryo

    2014-01-01

    Although the structure, function, conformational dynamics, and controlled thermodynamics of proteins are manifested by their corresponding amino acid sequences, the natural rules for molecular design and their corresponding interplay remain obscure. In this study, we focused on the role of internal cavities of proteins in conformational dynamics. We investigated the pressure-induced responses from the cavity-enlarged L99A mutant of T4 lysozyme, using high-pressure NMR spectroscopy. The signal intensities of the methyl groups in the 1H/13C HSQC spectra, particularly those around the enlarged cavity, decreased with the increasing pressure, and disappeared at 200 MPa, without the appearance of new resonances, thus indicating the presence of heterogeneous conformations around the cavity within the ground state ensemble. Above 200 MPa, the signal intensities of more than 20 methyl groups gradually decreased with the increasing pressure, without the appearance of new resonances. Interestingly, these residues closel...

  14. Deterministic coupling of delta-doped nitrogen vacancy centers to a nanobeam photonic crystal cavity

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jonathan C.; Cui, Shanying; Zhang, Xingyu; Russell, Kasey J.; Magyar, Andrew P.; Hu, Evelyn L., E-mail: ehu@seas.harvard.edu [School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138 (United States); Bracher, David O. [Department of Physics, Harvard University, Cambridge, Massachusetts 02138 (United States); Ohno, Kenichi; McLellan, Claire A.; Alemán, Benjamin; Bleszynski Jayich, Ania [Department of Physics, University of California, Santa Barbara, Santa Barbara, California 93106 (United States); Andrich, Paolo; Awschalom, David [Department of Physics, University of California, Santa Barbara, Santa Barbara, California 93106 (United States); Institute for Molecular Engineering, University of Chicago, Chicago, Illinois 60637 (United States); Aharonovich, Igor [School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138 (United States); School of Physics and Advanced Materials, University of Technology Sydney, Ultimo, New South Wales 2007 (Australia)

    2014-12-29

    The negatively charged nitrogen vacancy center (NV) in diamond has generated significant interest as a platform for quantum information processing and sensing in the solid state. For most applications, high quality optical cavities are required to enhance the NV zero-phonon line (ZPL) emission. An outstanding challenge in maximizing the degree of NV-cavity coupling is the deterministic placement of NVs within the cavity. Here, we report photonic crystal nanobeam cavities coupled to NVs incorporated by a delta-doping technique that allows nanometer-scale vertical positioning of the emitters. We demonstrate cavities with Q up to ∼24 000 and mode volume V ∼ 0.47(λ/n){sup 3} as well as resonant enhancement of the ZPL of an NV ensemble with Purcell factor of ∼20. Our fabrication technique provides a first step towards deterministic NV-cavity coupling using spatial control of the emitters.

  15. Entanglements in a coupled cavity-array with one oscillating end-mirror

    Institute of Scientific and Technical Information of China (English)

    吴琴; 肖银; 张智明

    2015-01-01

    We theoretically investigate the entanglement properties in a hybrid system consisting of an optical cavity–array coupled to a mechanical resonator. We show that the steady state of the system presents bipartite continuous variable entanglement in an experimentally accessible parameter regime. The effects of the cavity–cavity coupling strength on the bipartite entanglements in the field–mirror subsystem and in the field–field subsystem are studied. We further find that the entanglement between the adjacent cavity and the movable mirror can be entirely transferred to the distant cavity and mirror by properly choosing the cavity detunings and the coupling strength in the two-cavity case. Surprisingly, such a remote macroscopic entanglement tends to be stable in the large coupling regime and persists for environment temperatures at above 25 K in the three-cavity case. Such optomechanical systems can be used for the realization of continuous variable quantum information interfaces and networks.

  16. Operation of the 56 MHz superconducting RF cavity in RHIC during run 14

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Q. [Brookhaven National Lab. (BNL), Upton, NY (United States); Belomestnykh, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., NY (United States); Ben-Zvi, I. [Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., NY (United States); Blaskiewicz, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Hayes, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Mernick, K. [Brookhaven National Lab. (BNL), Upton, NY (United States); Severino, F. [Brookhaven National Lab. (BNL), Upton, NY (United States); Smith, K. [Brookhaven National Lab. (BNL), Upton, NY (United States); Zaltsman, A. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-09-11

    A 56 MHz superconducting RF cavity was designed and installed in the Relativistic Heavy Ion Collider (RHIC). It is the first superconducting quarter wave resonator (QWR) operating in a high-energy storage ring. We discuss herein the cavity operation with Au+Au collisions, and with asymmetrical Au+He3 collisions. The cavity is a storage cavity, meaning that it becomes active only at the energy of experiment, after the acceleration cycle is completed. With the cavity at 300 kV, an improvement in luminosity was detected from direct measurements, and the bunch length has been reduced. The uniqueness of the QWR demands an innovative design of the higher order mode dampers with high-pass filters, and a distinctive fundamental mode damper that enables the cavity to be bypassed during the acceleration stage.

  17. Ultracompact optical circulator based on a uniformly magnetic magnetophotonic annular Bragg cavity

    CERN Document Server

    Śmigaj, Wojciech; Romero-Vivas, Javier; Guenneau, Sébastien; Dagens, Béatrice; Gralak, Boris; Vanwolleghem, Mathias

    2011-01-01

    We have developed a theoretical framework that allows an efficient design of integrated optical circulators based on non-reciprocal magneto-optical cavities. Using this approach we have analysed different possible layouts for nonreciprocal resonant cavities. This investigation has allowed us to propose a new class of miniaturized integrated optical circulators that achieve simultaneously strong optical circulation while maintaining reasonable technological feasibility. Their layout is based on a radial Bragg cavity formed by arranging centrosymmetric annular magneto-optic rings. The circulator ports are standard rib waveguides, butt-coupled to the ring cavity by possibly cutting the outer cavity rings. Using a coupled mode description of the complete cavity/waveguide-port system, it is shown that it is indispensable to take possible direct port-to-port coupling into account for a proper optimization of the device. Including these optimization parameters in finite element simulations has led us to propose a st...

  18. Nonradiating and radiating modes excited by quantum emitters in open epsilon-near-zero cavities

    CERN Document Server

    Liberal, Iñigo

    2015-01-01

    Controlling the emission and interaction properties of quantum emitters (QEs) embedded within an optical cavity is a key technique in engineering light-matter interactions at the nanoscale, as well as in the development of quantum information processing. State-of-the-art optical cavities are based on high Q photonics crystals and dielectric resonators. However, wealthier responses might be attainable with cavities carved in more exotic materials. Here, we theoretically investigate the emission and interaction properties of QEs embedded in open epsilon-near-zero (ENZ) cavities. Using analytical methods and numerical simulations, it is demonstrated that open ENZ cavities present the unique property of supporting nonradiating modes independently of the geometry of the external boundary of the cavity (shape, size, topology...). Moreover, the possibility of switching between radiating and nonradiating modes enables a dynamic control of both the emission by, and the interaction between, QEs. These phenomena provide...

  19. Theoretical and experimental researches on C-band three-cavity transit-time effect oscillator

    Institute of Scientific and Technical Information of China (English)

    FAN Zhikai; LIU Qingxiang; CHEN Daibing; TAN Jie; ZHOU Haijing

    2004-01-01

    The C-band three-cavity transit-time effect oscillator (3C TTTO) is a novel high power microwave device based on the transit-time effect of the three-cavity (3C) resonator. The operational principle of this device is briefly expounded in this paper, and the theoretical and experimental researches on the radial insulation diode, the 3C resonator, the double-gap output cavity and the circular waveguide bevel cut radiation antenna are presented in detail. By using the analytic method, the eigen modes and their field distributions of the 3C resonator are developed, and some basic laws of the transit-time effect are obtained in non-( mode field of the 3C resonator. At last, the experimental results are given. This device generated RF peak power in excess of 400MW with 15ns FWHM, and its beam-wave power conversion efficiency is about 17%.

  20. Graphene photonics for resonator-enhanced electro-optic devices and all-optical interactions

    Energy Technology Data Exchange (ETDEWEB)

    Englund, Dirk R.; Gan, Xuetao

    2017-03-21

    Techniques for coupling light into graphene using a planar photonic crystal having a resonant cavity characterized by a mode volume and a quality factor and at least one graphene layer positioned in proximity to the planar photonic crystal to at least partially overlap with an evanescent field of the resonant cavity. At least one mode of the resonant cavity can couple into the graphene layer via evanescent coupling. The optical properties of the graphene layer can be controlled, and characteristics of the graphene-cavity system can be detected. Coupling light into graphene can include electro-optic modulation of light, photodetection, saturable absorption, bistability, and autocorrelation.