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Sample records for microstrip ring resonator

  1. Microstrip Ring Resonator for Soil Moisture Measurements

    NASA Technical Reports Server (NTRS)

    Sarabandi, Kamal; Li, Eric S.

    1993-01-01

    Accurate determination of spatial soil moisture distribution and monitoring its temporal variation have a significant impact on the outcomes of hydrologic, ecologic, and climatic models. Development of a successful remote sensing instrument for soil moisture relies on the accurate knowledge of the soil dielectric constant (epsilon(sub soil)) to its moisture content. Two existing methods for measurement of dielectric constant of soil at low and high frequencies are, respectively, the time domain reflectometry and the reflection coefficient measurement using an open-ended coaxial probe. The major shortcoming of these methods is the lack of accurate determination of the imaginary part of epsilon(sub soil). In this paper a microstrip ring resonator is proposed for the accurate measurement of soil dielectric constant. In this technique the microstrip ring resonator is placed in contact with soil medium and the real and imaginary parts of epsilon(sub soil) are determined from the changes in the resonant frequency and the quality factor of the resonator respectively. The solution of the electromagnetic problem is obtained using a hybrid approach based on the method of moments solution of the quasi-static formulation in conjunction with experimental data obtained from reference dielectric samples. Also a simple inversion algorithm for epsilon(sub soil) = epsilon'(sub r) + j(epsilon"(sub r)) based on regression analysis is obtained. It is shown that the wide dynamic range of the measured quantities provides excellent accuracy in the dielectric constant measurement. A prototype microstrip ring resonator at L-band is designed and measurements of soil with different moisture contents are presented and compared with other approaches.

  2. TlCaBaCuO high Tc superconducting microstrip ring resonators designed for 12 GHz

    NASA Technical Reports Server (NTRS)

    Subramanyam, G.; Kapoor, V. J.; Chorey, C. M.; Bhasin, K. B.

    1993-01-01

    Microwave properties of sputtered Tl-Ca-Ba-Cu-O thin films were investigated by designing, fabricating, and testing microstrip ring resonators. Ring resonators designed for 12 GHz fundamental resonance frequency, were fabricated and tested. From the unloaded Q values for the resonators, the surface resistance was calculated by separating the conductor losses from the total losses. The penetration depth was obtained from the temperature dependence of resonance frequency, assuming that the shift in resonance frequency is mainly due to the temperature dependence of penetration depth. The effective surface resistance at 12 GHz and 77 K was determined to be between 1.5 and 2.75 mOmega, almost an order lower than Cu at the same temperature and frequency. The effective penetration depth at 0 K is approximately 7000 A.

  3. Compact ultra wide band microstrip bandpass filter based on multiple-mode resonator and modified complementary split ring resonator.

    PubMed

    Marcotegui, J Antonio; Illescas, Jesús Miguel; Estevez, Aritz; Falcone, Francisco

    2013-01-01

    A new class of broadband microstrip filters for Ultra Wide Band (UWB) applications is proposed. In the design, different stages of parallel-coupled microstrip line and other stages with a Modified Complementary Split Ring Resonator (MCSRR)-a concept proposed here for the first time-are adjusted to obtain the desired response with broadband, sharp rejection, low insertion loss, and low return loss. Full wave simulation results as well as measurement results from fabricated prototypes are presented, showing good agreement. The proposed technique offers a new alternative to implement low-cost high-performance filter devices, applicable to a wide range of communication systems.

  4. Radiation and Resonant Frequency of Superconducting Annular Ring Microstrip Antenna on Uniaxial Anisotropic Media

    NASA Astrophysics Data System (ADS)

    Barkat, Ouarda; Benghalia, Abdelmadjid

    2009-10-01

    In this work, the full-wave method is used for computing the resonant frequency, the bandwidth, and radiation pattern of High temperature superconductor, or an imperfectly conducting annular ring microstrip, which is printed on uniaxial anisotropic substrate. Galerkin’s method is used in the resolution of the electric field integral equation. The TM set of modes issued from the cavity model theory are used to expand the unknown currents on the patch. Numerical results concerning the effect of the anisotropic substrates on the antenna performance are presented and discussed. It is found that microstrip superconducting could give high efficiency with high gain in millimeter wavelengths. Results are compared with previously published data and are found to be in good agreement.

  5. Complementary split ring resonator metamaterial to achieve multifrequency operation in microstrip-based radiating structure design

    NASA Astrophysics Data System (ADS)

    Patel, Shobhit K.; Kosta, Yogeshwar

    2014-02-01

    Following recent findings on metamaterials, a miniaturized microstrip patch antenna loaded with a complementary split ring resonator (CSRR) was investigated for multiband operation. The proposed structure has a CSRR loaded in the base of the antenna to improve its performance and to make it a metamaterial. Metamaterials exhibit qualitatively new electromagnetic response functions that cannot be found in nature. The CSRR-loaded base allows simultaneous operation over several frequencies. Here, a total of seven bands were achieved by loading the patch antenna with the CSRR. The seven bands were centered around frequencies of 4.33 GHz, 5.29 GHz, 6.256 GHz, 7.066 GHz, 7.846 GHz, 8.86 GHz, and 9.75 GHz. Design results were obtained by using a high-frequency structure simulator that is used for simulating microwave passive components.

  6. Design and Analysis of Miniaturized Microstrip Patch Antenna with Metamaterials Based on Modified Split-Ring Resonator for UWB Applications

    NASA Astrophysics Data System (ADS)

    Khedrouche, D.; Bougoutaia, T.; Hocini, A.

    2016-11-01

    In this paper, a miniaturized microstrip patch antenna using a negative index metamaterial with modified split-ring resonator (SRR) unit cells is proposed for ultra-wideband (UWB) applications. The new design of metamaterial based microstrip patch antenna has been optimized to provide an improved bandwidth and multiple frequency operations. All the antenna performance parameters are presented in response-graphs. Also it is mentioned that the physical dimensions of the metamaterial based patch antenna are very small, which is convenient to modern communication. A 130 % bandwidth, covering the frequency band of 2.9-13.5 GHz, (for return loss less than or equal -10 dB) is achieved, which allow the antenna to operate in the Federal Communication Commission (FCC) band. In addition, the antenna has a good radiation pattern in the ultra-wide band spectrum, and it is nearly omnidirectional.

  7. Tunable superconducting microstrip resonators

    NASA Astrophysics Data System (ADS)

    Adamyan, A. A.; Kubatkin, S. E.; Danilov, A. V.

    2016-04-01

    We report on a simple yet versatile design for a tunable superconducting microstrip resonator. Niobium nitride is employed as the superconducting material and aluminum oxide, produced by atomic layer deposition, as the dielectric layer. We show that the high quality of the dielectric material allows to reach the internal quality factors in the order of Qi˜104 in the single photon regime. Qi rapidly increases with the number of photons in the resonator N and exceeds 105 for N ˜10 -50 . A straightforward modification of the basic microstrip design allows to pass a current bias through the strip and to control its kinetic inductance. We achieve a frequency tuning δf =62 MHz around f0=2.4 GHz for a fundamental mode and δf =164 MHz for a third harmonic. This translates into a tuning parameter Qiδf /f0=150 . The presented design can be incorporated into essentially any superconducting circuitry operating at temperatures below 2.5 K.

  8. Square-tooth split ring resonator - a novel metamaterial for bandwidth and radiation improvement in microstrip-based radiating structure design

    NASA Astrophysics Data System (ADS)

    Patel, Shobhit K.; Kosta, Y. P.

    2013-11-01

    A square multiband truncated microstrip patch antenna was investigated using a square-tooth split ring resonator for multiband applications in both S- and C-bands. The square-tooth split ring resonator is formed from metallic inclusions in a substrate to create a metamaterial. We introduce a new square-tooth split ring resonator which increases the radiation of the antenna as well as the bandwidth. This new design creates a slow wave structure. The square-tooth addition to the split ring resonator works like a slow wave structure. The square-tooth split ring resonator design is compared with the simple split ring resonator design. The square-tooth design has four bands with center frequencies of 3.88, 4.81, 5.4, and 5.62 GHz, whereas design with the simple split ring resonator has just three bands with center frequencies of 3.88, 4.74, and 5.50 GHz. The bandwidth is increased by 20% to 30% using the square-tooth split ring resonator compared to the simple split ring resonator.

  9. A Novel Symmetrical Split Ring Resonator Based on Microstrip for Microwave Sensors

    NASA Astrophysics Data System (ADS)

    Alahnomi, Rammah A.; Zakaria, Z.; Ruslan, E.; Bahar, Amyrul Azuan Mohd

    2016-02-01

    In this paper, novel symmetrical split ring resonator (SSRR) is proposed as a suitable component for performance enhancement of microwave sensors. SSRR has been employed for enhancing the insertion loss of the microwave sensors. Using the same device area, we can achieve a high Q-factor of 141.54 from the periphery enhancement using Quasi-linear coupling SSRR, whereas loose coupling SSRR can achieve a Q-factor of 33.98 only. Using Quasi-linear coupling SSRR, the Q-factor is enhanced 4.16 times the loose coupling SSRR using the same device area. After the optimization was made, the SSRR sensor with loose coupling scheme has achieved a very high Qfactor value around 407.34 while quasi-linear scheme has achieved high Q-factor value of 278.78 at the same operating frequency with smaller insertion loss. Spurious passbands at 1st, 2nd, 3rd, and 4th harmonics have been completely suppressed well above -20 dB rejection level without visible changes in the passband filter characteristics. The most significant of using SSRR is to be used for various industrial applications such as food industry, quality control, bio-sensing medicine and pharmacy. The simulation result that Quasi-linear coupling SSRR is a viable candidate for the performance enhancement of microwave sensors has been verified.

  10. Simple analysis and design of annular ring microstrip antennas

    NASA Astrophysics Data System (ADS)

    El-Khamy, S. E.; El-Awadi, R. M.; El-Sharrawy, E.-B. A.

    1986-06-01

    A simple analysis of thin annular-ring microstrip antennas (AR-MSA), along with a design technique that yields the optimum ring dimensions which maximizes the radiation efficiency and the bandwidth, is presented in this paper. Using the cavity model, exact closed form solutions for the radiation fields are derived. The antenna fields distribution, resonance dimensions, radiation patterns, directivity, radiation conductance, quality factor and bandwidth are investigated for the different TMnm modes. AR-MSAs operated at the high order TMn2 modes are found to have better radiation properties and broader bandwidths than the corresponding disk-MSAs. A design table for the optimum ring dimensions for different types of the dielectric substrate material is also given in the paper.

  11. Optimization of Circular Ring Microstrip Antenna Using Genetic Algorithm

    NASA Astrophysics Data System (ADS)

    Sathi, V.; Ghobadi, Ch.; Nourinia, J.

    2008-10-01

    Circular ring microstrip antennas have several interesting properties that make it attractive in wireless applications. Although several analysis techniques such as cavity model, generalized transmission line model, Fourier-Hankel transform domain and the method of matched asymptotic expansion have been studied by researchers, there is no efficient design tool that has been incorporated with a suitable optimization algorithm. In this paper, the cavity model analysis along with the genetic optimization algorithm is presented for the design of circular ring microstrip antennas. The method studied here is based on the well-known cavity model and the optimization of the dimensions and feed point location of the circular ring antenna is performed via the genetic optimization algorithm, to achieve an acceptable antenna operation around a desired resonance frequency. The antennas designed by this efficient design procedure were realized experimentally, and the results are compared. In addition, these results are also compared to the results obtained by the commercial electromagnetic simulation tool, the FEM based software, HFSS by ANSOFT.

  12. Extended analysis of closed-ring microstrip antenna

    NASA Astrophysics Data System (ADS)

    Sultan, M. A.

    1989-02-01

    Gauss' hypergeometric function and Euler's transformation are employed to analyze the radiation characteristics of a closed-ring microstrip antenna. The method takes into account ohmic and dielectric losses, and it is used to determine relations between efficiency and bandwidth. It is found that at higher frequencies, narrower ring structures can have small Q-factors, high gain, and large bandwidth.

  13. Composite arrays of superconducting microstrip line resonators

    SciTech Connect

    Mohebbi, H. R. Miao, G. X.; Benningshof, O. W. B.; Taminiau, I. A. J.; Cory, D. G.

    2014-03-07

    A novel design of an array of half-wave superconductive microstrip resonators is described. The resonator is intended to be useful for electron spin resonance studies of thin film samples at cryogenic temperatures. It achieves a high quality factor, has a small mode-volume, and creates a uniform magnetic field in a plane above the resonator. The device is made of thin film Niobium on sapphire wafer and is tested with a static magnetic field. Variation of Q-factor versus the magnetic field's strength at different temperatures is reported and is in a good agreement with simulation when the loss due to the vortices is included. Also, the power-dependence response of the resonator is shown in experiments and is verified by capturing the nonlinearity associated with the surface impedance of the superconducting film into the circuit model of the device.

  14. Nonlinearity of superconducting transmission line and microstrip resonator

    SciTech Connect

    Vendik, O.G.; Vendik, I.B.; Samoilova, T.B.

    1997-02-01

    The simplest model of nonlinear response of a superconducting thin film is used for modeling the nonlinear phenomena in a superconducting transmission line and a microstrip resonator. The specified characteristic power of the transmission line is suggested to use as a fitting parameter for numerical description of the microstrip line nonlinearity at microwaves. Quantitative agreement of simulated and experimental data has been obtained for the incident power dependent transmission coefficient of a microstrip line section and a high quality microstrip resonator. Numerical results have also been obtained for the power of the third harmonic radiated from the nonlinear resonator.

  15. Comparison of Ring Resonator Relative Permittivity Measurements to Ground Penetrating Radar Data

    DTIC Science & Technology

    2014-04-01

    permittivity of the soil and the target is critical in determining the strength of the reflection from the target. In this paper, a microstrip ring resonator...is used to measure the relative permittivity of the soil and various target fill materials. For this measurement technique, a microstrip ring...The microstrip ring resonator is a tool to measure the real and imaginary permittivity of soil samples in-situ, rather than requiring samples to be

  16. A Compact Annular Ring Microstrip Antenna for WSN Applications

    PubMed Central

    Wang, Daihua; Song, Linli; Zhou, Hanchang; Zhang, Zhijie

    2012-01-01

    A compact annular ring microstrip antenna was proposed for a wireless sensor network (WSN) application in the 2.4 GHz band. In this paper the major considerations of the conformal antenna design were the compact size and the impact on antenna's performance of a steel installation base. By using a chip resistor of large resistance (120 Ω) the antenna size was reduced to 38% of that a conventional annular ring patch antenna. With the addition of the steel installation base the resonant frequency of the antenna increases about 4.2% and the bandwidth reduces from 17.5% to 11.7% by adjusting the load resistance simultaneously. Several key parameters were discussed and optimized, and the antenna was fabricated and its performance measured. The antenna is well matched at 2.4 GHz with 34.2 dB return loss and –2.5 dBi peak gain. Meanwhile, it exhibits excellent radiation patterns with very low cross-polarization levels. PMID:23012510

  17. A compact annular ring microstrip antenna for WSN applications.

    PubMed

    Wang, Daihua; Song, Linli; Zhou, Hanchang; Zhang, Zhijie

    2012-01-01

    A compact annular ring microstrip antenna was proposed for a wireless sensor network (WSN) application in the 2.4 GHz band. In this paper the major considerations of the conformal antenna design were the compact size and the impact on antenna's performance of a steel installation base. By using a chip resistor of large resistance (120 Ω) the antenna size was reduced to 38% of that a conventional annular ring patch antenna. With the addition of the steel installation base the resonant frequency of the antenna increases about 4.2% and the bandwidth reduces from 17.5% to 11.7% by adjusting the load resistance simultaneously. Several key parameters were discussed and optimized, and the antenna was fabricated and its performance measured. The antenna is well matched at 2.4 GHz with 34.2 dB return loss and -2.5 dBi peak gain. Meanwhile, it exhibits excellent radiation patterns with very low cross-polarization levels.

  18. Ringing phenomenon of the fiber ring resonator.

    PubMed

    Ying, Diqing; Ma, Huilian; Jin, Zhonghe

    2007-08-01

    A resonator fiber-optic gyro (R-FOG) is a high-accuracy inertial rotation sensor based on the Sagnac effect. A fiber ring resonator is the core sensing element in the R-FOG. When the frequency of the fiber ring resonator input laser is swept linearly with time, ringing of the output resonance curve is observed. The output field of the fiber ring resonator is derived from the superposition of the light transmitted through the directional coupler directly and the multiple light components circulated in the fiber ring resonator when the frequency of the laser is swept. The amplitude and phase of the output field are analyzed, and it is found that the difference in time for different light components in the fiber ring resonator to reach a point of destructive interference causes the ringing phenomenon. Finally the ringing phenomenon is observed in experiments, and the experimental results agree with the theoretical analysis well.

  19. YBCO superconducting ring resonators at millimeter-wave frequencies

    NASA Technical Reports Server (NTRS)

    Chorey, Christopher M.; Kong, Keon-Shik; Bhasin, Kul B.; Warner, J. D.; Itoh, Tatsuo

    1991-01-01

    Microstrip ring resonators operating at 35 GHz were fabricated from laser ablated YBCO films deposited on lanthanum aluminate substrates. They were measured over a range of temperatures and their performances compared to identical resonators made of evaporated gold. Below 60 Kelvin the superconducting strip performed better than the gold, reaching an unloaded Q approximately 1.5 times that of gold at 25 K. A shift in the resonant frequency follows the form predicted by the London equations. The Phenomenological Loss Equivalence Method is applied to the ring resonator and the theoretically calculated Q values are compared to the experimental results.

  20. Spoof localized surface plasmons on ultrathin textured MIM ring resonator with enhanced resonances.

    PubMed

    Zhou, Yong Jin; Xiao, Qian Xun; Yang, Bao Jia

    2015-09-30

    We numerically demonstrate that spoof localized surface plasmons (LSPs) resonant modes can be enhanced based on ultrathin corrugated metal-insulator-metal (MIM) ring resonator. Further enhancement of the LSPs modes has been achieved by incorporating an efficient and ease-of-integration exciting method. Quality factors of resonance peaks have become much larger and multipolar resonances modes can be easily observed on the textured MIM ring resonator excited by a microstrip line. Experimental results validate the high-efficiency excitation and resonance enhancements of spoof LSPs modes on the MIM ring resonator in the microwave frequencies. We have shown that the fabricated resonator is sensitive to the variation of both the dielectric constant and the thickness of surrounding materials under test. The spoof plasmonic resonator can be used as key elements to provide many important device functionalities such as optical communications, signal processing, and spectral engineering in the plasmonic integration platform.

  1. Spoof localized surface plasmons on ultrathin textured MIM ring resonator with enhanced resonances

    PubMed Central

    Zhou, Yong Jin; Xiao, Qian Xun; Jia Yang, Bao

    2015-01-01

    We numerically demonstrate that spoof localized surface plasmons (LSPs) resonant modes can be enhanced based on ultrathin corrugated metal-insulator-metal (MIM) ring resonator. Further enhancement of the LSPs modes has been achieved by incorporating an efficient and ease-of-integration exciting method. Quality factors of resonance peaks have become much larger and multipolar resonances modes can be easily observed on the textured MIM ring resonator excited by a microstrip line. Experimental results validate the high-efficiency excitation and resonance enhancements of spoof LSPs modes on the MIM ring resonator in the microwave frequencies. We have shown that the fabricated resonator is sensitive to the variation of both the dielectric constant and the thickness of surrounding materials under test. The spoof plasmonic resonator can be used as key elements to provide many important device functionalities such as optical communications, signal processing, and spectral engineering in the plasmonic integration platform. PMID:26420668

  2. High-frequency microstrip cross resonators for circular polarization electron paramagnetic resonance spectroscopy.

    PubMed

    Henderson, J J; Ramsey, C M; Quddusi, H M; del Barco, E

    2008-07-01

    In this article we discuss the design and implementation of a novel microstrip resonator which allows absolute control of the microwaves polarization degree for frequencies up to 30 GHz. The sensor is composed of two half-wavelength microstrip line resonators, designed to match the 50 Omega impedance of the lines on a high dielectric constant GaAs substrate. The line resonators cross each other perpendicularly through their centers, forming a cross. Microstrip feed lines are coupled through small gaps to three arms of the cross to connect the resonator to the excitation ports. The control of the relative magnitude and phase between the two microwave stimuli at the input ports of each line allows for tuning the degree and type of polarization of the microwave excitation at the center of the cross resonator. The third (output) port is used to measure the transmitted signal, which is crucial to work at low temperatures, where reflections along lengthy coaxial lines mask the signal reflected by the resonator. Electron paramagnetic resonance spectra recorded at low temperature in an S=5/2 molecular magnet system show that 82% fidelity circular polarization of the microwaves is achieved over the central area of the resonator.

  3. Sub-terahertz and terahertz microstrip resonant-tunneling-diode oscillators

    SciTech Connect

    Feiginov, Michael

    2015-09-21

    We present a theoretical analysis of traveling-wave microstrip resonant-tunneling-diode (RTD) oscillators. Such oscillators are similar to terahertz (THz) quantum-cascade lasers (QCLs) with a metal-metal waveguide and with just the active part of a single QCL period (an RTD) as their active core. Assuming realistic parameters of RTDs, we show that the microstrip RTD oscillators should be working at sub-THz and THz frequencies. Contrary to the contemporary THz QCLs, RTD microstrips are room-temperature oscillators. The major loss- and gain-enhancement mechanisms in RTD microstrips are identified.

  4. Resonance capture and Saturn's rings

    SciTech Connect

    Patterson, C.W.

    1986-05-01

    We have assigned the resonances apparently responsible for the stabilization of the Saturn's shepherd satellites and for the substructure seen in the F-ring and the ringlets in the C-ring. We show that Saturn's narrow ringlets have a substructure determined by three-body resonances with Saturn's ringmoons and the sun. We believe such resonances have important implications to satellite formation. 17 refs., 1 fig., 1 tab.

  5. Resonance splitting in gyrotropic ring resonators.

    PubMed

    Jalas, Dirk; Petrov, Alexander; Krause, Michael; Hampe, Jan; Eich, Manfred

    2010-10-15

    We present the theoretical concept of an optical isolator based on resonance splitting in a silicon ring resonator covered with a magneto-optical polymer cladding. For this task, a perturbation method is derived for the modes in the cylindrical coordinate system. A polymer magneto-optical cladding causing a 0.01 amplitude of the off-diagonal element of the dielectric tensor is assumed. It is shown that the derived resonance splitting of the clockwise and counterclockwise modes increases for smaller ring radii. For the ring with a radius of approximately 1.5μm, a 29GHz splitting is demonstrated. An integrated optical isolator with a 10μm geometrical footprint is proposed based on a critically coupled ring resonator.

  6. Optimization of substrate dielectric and mode of microstrip ring antenna for high efficiency and directivity

    NASA Astrophysics Data System (ADS)

    Vaitheeswaran Iyer, S. M.; Joshi, A. W.; Karekar, R. N.

    1993-07-01

    Fields of microstrip ring antennas are calculated using a theoretical formulation based on the Green's function in conjunction with the reflection coefficient matrix approach. The effect of surface wave excitation on the efficiency of space wave launching of an annular ring antenna is analyzed, focusing on the case when the antenna is operated at higher-order modes. It is shown that the ring antenna outperforms disk and rectangular patch antennas and exhibits optimized performance for the TM sub 12 mode, with a substrate dielectric constant of 6 with high gain, broad lobe width, and no side lobes. It is considered to be a good candidate for array synthesis even in MMIC.

  7. Ring resonant cavities for spectroscopy

    DOEpatents

    Zare, R.N.; Martin, J.; Paldus, B.A.; Xie, J.

    1999-06-15

    Ring-shaped resonant cavities for spectroscopy allow a reduction in optical feedback to the light source, and provide information on the interaction of both s- and p-polarized light with samples. A laser light source is locked to a single cavity mode. An intracavity acousto-optic modulator may be used to couple light into the cavity. The cavity geometry is particularly useful for Cavity Ring-Down Spectroscopy (CRDS). 6 figs.

  8. Ring resonant cavities for spectroscopy

    DOEpatents

    Zare, Richard N.; Martin, Juergen; Paldus, Barbara A.; Xie, Jinchun

    1999-01-01

    Ring-shaped resonant cavities for spectroscopy allow a reduction in optical feedback to the light source, and provide information on the interaction of both s- and p-polarized light with samples. A laser light source is locked to a single cavity mode. An intracavity acousto-optic modulator may be used to couple light into the cavity. The cavity geometry is particularly useful for Cavity Ring-Down Spectroscopy (CRDS).

  9. Apex-angle-dependent resonances in triangular split-ring resonators

    NASA Astrophysics Data System (ADS)

    Burnett, Max A.; Fiddy, Michael A.

    2016-02-01

    Along with other frequency selective structures (Pendry et al. in IEEE Trans Microw Theory Tech 47(11):2075-2084, 1999) (circles and squares), triangular split-ring resonators (TSRRs) only allow frequencies near the center resonant frequency to propagate. Further, TSRRs are attractive due to their small surface area (Vidhyalakshmi et al. in Stopband characteristics of complementary triangular split ring resonator loaded microstrip line, 2011), comparatively, and large quality factors ( Q) as previously investigated by Gay-Balmaz et al. (J Appl Phys 92(5):2929-2936, 2002). In this work, we examine the effects of varying the apex angle on the resonant frequency, the Q factor, and the phase shift imparted by the TSRR element within the GHz frequency regime.

  10. Performance and modeling of superconducting ring resonators at millimeter-wave frequencies

    NASA Technical Reports Server (NTRS)

    Bhasin, K. B.; Chorey, C. M.; Warner, J. D.; Romanofsky, R. R.; Heinen, V. O.; Kong, K. S.; Lee, H. Y.; Itoh, T.

    1990-01-01

    Microstrip ring resonators operating at 35 GHz were fabricated from laser ablated YBCO thin films deposited on lanthanum aluminate substrates. They were measured over a range of temperatures and their performance compared to identical resonators made of evaporated gold. Below 60 Kelvin the superconducting strip performed better than the gold, reaching an unloaded Q approximately 1.5 times that of gold at 25 K. A shift in the resonant frequency follows the form predicted by the London equations. The Phenomenological Loss Equivalence Method is applied to the ring resonator and the theoretically calculated Q values are compared to the experimental results.

  11. Swept frequency technique for dispersion measurement of microstrip lines

    NASA Technical Reports Server (NTRS)

    Lee, Richard Q.

    1987-01-01

    Microstrip lines used in microwave integrated circuits are dispersive. Because a microstrip line is an open structure, the dispersion can not be derived with pure TEM, TE, or TM mode analysis. Dispersion analysis has commonly been done using a spectral domain approach, and dispersion measurement has been made with high Q microstrip ring resonators. Since the dispersion of a microstrip line is fully characterized by the frequency dependent phase velocity of the line, dispersion measurement of microstrip lines requires the measurement of the line wavelength as a function of frequency. In this paper, a swept frequency technique for dispersion measurement is described.

  12. Analysis of Alternative Ring Resonator Designs

    DTIC Science & Technology

    2014-08-01

    the ring strip of the antenna as in the case of the original design. Both the alternative dielectric laminate and the increased thickness laminate...adjustments to the geometry parameters. 2. Ring Resonator Antenna Design The ring resonator is a two port antenna consisting of a ring strip and two...differing thicknesses for resonator antennas of the same design suggests that the RF fields penetrate slightly more or that the resonator can “see” a

  13. Wavelength-tunable optical ring resonators

    DOEpatents

    Watts, Michael R.; Trotter, Douglas C.; Young, Ralph W.; Nielson, Gregory N.

    2009-11-10

    Optical ring resonator devices are disclosed that can be used for optical filtering, modulation or switching, or for use as photodetectors or sensors. These devices can be formed as microdisk ring resonators, or as open-ring resonators with an optical waveguide having a width that varies adiabatically. Electrical and mechanical connections to the open-ring resonators are made near a maximum width of the optical waveguide to minimize losses and thereby provide a high resonator Q. The ring resonators can be tuned using an integral electrical heater, or an integral semiconductor junction.

  14. Wavelength-tunable optical ring resonators

    DOEpatents

    Watts, Michael R.; Trotter, Douglas C.; Young, Ralph W.; Nielson, Gregory N.

    2011-07-19

    Optical ring resonator devices are disclosed that can be used for optical filtering, modulation or switching, or for use as photodetectors or sensors. These devices can be formed as microdisk ring resonators, or as open-ring resonators with an optical waveguide having a width that varies adiabatically. Electrical and mechanical connections to the open-ring resonators are made near a maximum width of the optical waveguide to minimize losses and thereby provide a high resonator Q. The ring resonators can be tuned using an integral electrical heater, or an integral semiconductor junction.

  15. Circularly split-ring-resonator-based frequency-reconfigurable antenna

    NASA Astrophysics Data System (ADS)

    Rahman, M. A.; Faruque, M. R. I.; Islam, M. T.

    2017-01-01

    In this paper, an antenna with frequency configurability in light of a circularly split-ring resonator (CSRR) is introduced. The proposed reconfigurable monopole antenna consists of a microstrip-fed hook-shaped structure and a CSRR having single reconfigurable split only. A new band of radiation unlike the band radiated from monopole only is observed due to magnetic coupling between the CSRR and the monopole antenna. The resonance frequency of the CSRR can be arbitrarily chosen by varying the dimension and relative position of its gap with the monopole, which leads the antenna to become reconfigurable one. By using a single switch with perfect electric conductor at the gap of CSRR cell, the effect of CSRR can be deactivated and, hence, it is possible to suppress the corresponding resonance, resulting in a frequency-reconfigurable antenna. Commercially available Computer Simulation Technology microwave studio based on finite integration technique was adopted throughout the study.

  16. A Novel Miniaturization Technique of a Microstrip Patch Antenna using Patch Resonators

    NASA Astrophysics Data System (ADS)

    Kakita, Katsutoshi; Morita, Norihiko; Horii, Yasushi

    Microstrip patch antennas have been widely used in mobile and satellite communication systems due to their great advantages of low cost, low profile, lightweight and easy fabrication. However, the dimensions of a classical patch antenna are on the order of half a wavelength. This paper proposes a new approach to reduce the size of the antenna by embedding several patch resonators in an antenna substrate. Periodically installed resonators are expected to exhibit slow-wave effects. First of all, a microstrip delay line having a train of patch resonators in its substrate is demonstrated theoretically by the conventional FDTD method, and the slow-wave effect is discussed. Next, a 2-dimentional patch resonator array is applied to a microstrip patch antenna, and the effectiveness of the proposed structure is evaluated in the respect of antenna dimensions. Also, several experiments have been carried out to confirm the theoretical predictions. Using a prototype model fabricated on an LTCC substrate, the size reduction of more the 50% is attained.

  17. Coupled microstrip line transverse electromagnetic resonator model for high-field magnetic resonance imaging.

    PubMed

    Bogdanov, G; Ludwig, R

    2002-03-01

    The performance modeling of RF resonators at high magnetic fields of 4.7 T and more requires a physical approach that goes beyond conventional lumped circuit concepts. The treatment of voltages and currents as variables in time and space leads to a coupled transmission line model, whereby the electric and magnetic fields are assumed static in planes orthogonal to the length of the resonator, but wave-like along its longitudinal axis. In this work a multiconductor transmission line (MTL) model is developed and successfully applied to analyze a 12-element unloaded and loaded microstrip line transverse electromagnetic (TEM) resonator coil for animal studies. The loading involves a homogeneous cylindrical dielectric insert of variable radius and length. This model formulation is capable of estimating the resonance spectrum, field distributions, and certain types of losses in the coil, while requiring only modest computational resources. The boundary element method is adopted to compute all relevant transmission line parameters needed to set up the transmission line matrices. Both the theoretical basis and its engineering implementation are discussed and the resulting model predictions are placed in context with measurements. A comparison between a conventional lumped circuit model and this distributed formulation is conducted, showing significant departures in the resonance response at higher frequencies. This MTL model is applied to simulate two small-bore animal systems: one of 7.5-cm inner diameter, tuned to 200 MHz (4.7 T for proton imaging), and one of 13.36-cm inner diameter, tuned to both 200 and 300 MHz (7 T).

  18. Investigation of electromagnetic couplings between planar open-loop triangular-shaped resonators in microstrip and in multilayer technologies

    NASA Astrophysics Data System (ADS)

    Militaru, Nicolae

    2016-12-01

    The paper presents a study of the electromagnetic couplings between planar open-loop triangular-shaped resonators. Based on the proposed single-mode resonator, various couplings schemes are considered: between a single microstrip resonator and its 50Ω feeding line, between two identical triangular-shaped resonators designed in microstrip technology, and between pairs of synchronously-tuned resonators located on different metallization layers, in a multilayer configuration. In this last case, properly located slots, cut out in the common ground plane, ensure and control the coupling between resonators. The results shown in the paper can be used in the design of different miniature planar band-pass filters, including filters with cross-coupled resonators, in microstrip and in multilayer technologies.

  19. Adaptive Neuro-Fuzzy Inference System for Computing the Resonant Frequency of Circular Microstrip Antennas

    DTIC Science & Technology

    2004-11-01

    Use of Artificial Neural Networks,” Microwave and Optical Technology Letters, Vol.14, pp. 89-93, 1997. [41] S. Sagiroglu, K. Guney, and M. Erler ...Computer-Aided Engineering, Vol. 8, pp. 270- 277, 1998. [42] S. Sagiroglu, K. Guney, and M. Erler , “Calculation of Bandwidth for Electrically Thin and...S. Sagiroglu, and M. Erler , “Neural Computation of Resonant Frequency of Electrically Thin and Thick Rectangular Microstrip Antennas,” IEE. Proc

  20. Effective side length formula for resonant frequency of equilateral triangular microstrip antenna

    NASA Astrophysics Data System (ADS)

    Guney, Kerim; Kurt, Erhan

    2016-02-01

    A novel and accurate expression is obtained by employing the differential evolution algorithm for the effective side length (ESL) of the equilateral triangular microstrip antenna (ETMA). This useful formula allows the antenna engineers to accurately calculate the ESL of the ETMA. The computed resonant frequencies (RFs) show very good agreement with the experimental RFs when this accurate ESL formula is utilised for the computation of the RFs for the first five modes.

  1. Tilted microstrip phased arrays with improved electromagnetic decoupling for ultrahigh-field magnetic resonance imaging.

    PubMed

    Pang, Yong; Wu, Bing; Jiang, Xiaohua; Vigneron, Daniel B; Zhang, Xiaoliang

    2014-12-01

    One of the technical challenges in designing a dedicated transceiver radio frequency (RF) array for MR imaging in humans at ultrahigh magnetic fields is how to effectively decouple the resonant elements of the array. In this work, we propose a new approach using tilted microstrip array elements for improving the decoupling performance and potentially parallel imaging capability. To investigate and validate the proposed design technique, an 8-channel volume array with tilted straight-type microstrip elements was designed, capable for human imaging at the ultrahigh field of 7 Tesla. In this volume transceiver array, its electromagnetic decoupling behavior among resonant elements, RF field penetration to biological samples, and parallel imaging performance were studied through bench tests and in vivo MR imaging experiments. In this specific tilted element array design, decoupling among array elements changes with the tilted angle of the elements and the best decoupling can be achieved at certain tilted angle. In vivo human knee MR images were acquired using the tilted volume array at 7 Tesla for method validation. Results of this study demonstrated that the electromagnetic decoupling between array elements and the B1 field strength can be improved by using the tilted element method in microstrip RF coil array designs at the ultrahigh field of 7T.

  2. Satellite Mean Motion Resonances in Saturn's Rings

    NASA Astrophysics Data System (ADS)

    Gordon, Mitchell K.; Murray, C. D.; Showalter, M. R.

    2006-09-01

    We report on work to develop an atlas of satellite mean motion resonance locations and strengths within the rings of Saturn. Using the full literal expansion of the disturbing function, we identify locations of 1st, 2nd and selected 3rd order resonances. We show representative portions of the preliminary atlas in this paper. Our atlas allows for resonance splitting and includes weaker resonances than in the only previously available atlas (Lissauer & Cuzzi, 1982). Consequently, the new atlas will contain a substantially larger set of mean motion resonance locations within the rings. Our results are in good agreement with those of Lissauer & Cuzzi although a few resonance locations differ by a few to several kilometers. When completed, the atlas will be available through the PDS Rings Node, http://pds-rings.seti.org/.

  3. The effect of coupling line loss in microstrip to dielectric resonator coupling

    NASA Technical Reports Server (NTRS)

    Hearn, C. P.; Bradshaw, E. S.; Trew, R. J.

    1990-01-01

    The interaction between a dielectric resonator and a microstrip transmission line is fundamentally a field phenomenon. However, the model of Figure 1b widely is used to represent the arrangement in Figure 1a, and predicts the behavior encountered in practice. The microstrip line of length l = n(lambda)/4 between the input and coupling planes and the lambda/4 open-circuit stub usually is assumed to be lossless. This paper considers the effect of coupling line loss on the unloaded-Q and coupling coefficient beta of the combination. It shows that transmission line loss can cause the decrease in unloaded-Q that has been observed to occur with tight coupling, and limits the coupling coefficient to a much lower value than would be obtained with a lossless coupling line.

  4. Spoof localized surface plasmons in corrugated ring structures excited by microstrip line.

    PubMed

    Yang, Bao Jia; Zhou, Yong Jin; Xiao, Qian Xun

    2015-08-10

    We have investigated the fundamental and high-order spoof localized surface plasmons (LSPs) modes in the proposed corrugated ring resonator printed on a thin dielectric substrate with or without ground plane. An efficient and ease-of-integration method to excite spoof LSPs in the textured ring resonator has been adopted to suppress unwanted high-order modes and enhance fundamental modes. A multi-band-pass filter has been proposed and numerically demonstrated. Experimental results at the microwave frequencies verify the high performances of the corrugated ring resonator and the filter, showing great agreements with the simulation results. We have also shown that the fabricated device is sensitive to the variation of the refraction index of materials under test, even when the material is as thin as paper.

  5. Resonant elements contactless coupled to bolometric micro-stripes

    NASA Astrophysics Data System (ADS)

    Cuadrado, Alexander; Silva-López, Manuel; López-Alonso, José M.; Martínez-Antón, Juan C.; Ezquerro, José M.; González, Francisco J.; Alda, Javier

    2015-08-01

    One of the main technical difficulties in the fabrication of optical antennas working as light detectors is the proper design and manufacture of auxiliary elements as load lines and signal extraction structures. These elements need to be quite small to reach the location of the antennas and should have a minimal effect on the response of the device. Unfortunately this is not an easy task and signal extraction lines resonate along with the antenna producing a complex signal that usually masks the one given by the antenna. In order to decouple the resonance from the transduction we present in this contribution a parametric analysis of the response of a bolometric stripe that is surrounded by resonant dipoles with different geometries and orientations. We have checked that these elements should provide a signal proportional to the polarization state of the incoming light.

  6. A new design of a miniature filter on microstrip resonators with an interdigital structure of conductors

    NASA Astrophysics Data System (ADS)

    Belyaev, B. A.; Serzhantov, A. M.; Bal'va, Ya. F.; Leksikov, An. A.; Galeev, R. G.

    2015-05-01

    A microstrip bandpass filter of new design based on original resonators with an interdigital structure of conductors has been studied. The proposed filters of third to sixth order are distinguished for their high frequency-selective properties and much smaller size than analogs. It is established that a broad stop band, extending up to a sixfold central bandpass frequency, is determined by low unloaded Q of higher resonance mode and weak coupling of resonators in the pass band. It is shown for the first time that, as the spacing of interdigital stripe conductors decreases, the Q of higher resonance mode monotonically drops, while the Q value for the first operating mode remains high. A prototype fourth-order filter with a central frequency of 0.9 GHz manufactured on a ceramic substrate with dielectric permittivity ɛ = 80 has microstrip topology dimensions of 9.5 × 4.6 × 1 mm3. The electrodynamic 3D model simulations of the filter characteristics agree well with the results of measurements.

  7. A Study of Microstrip Line Balanced Filters with Attenuation Poles Based on Tapped Resonators

    NASA Astrophysics Data System (ADS)

    Kubo, Yoshiyuki; Wada, Kouji

    We propose microstrip-line balanced filters with controllable attenuation poles by using tapped resonators. These filters are basically composed of a coupled-line and tapped resonators. The coupled-line provides bandpass responses with attenuation poles and balanced filter operation. Also, the tappd resonators provide bandpass responses and attenuation poles. The position and number of the attenuation pole are controlled by the choice of the kind of the tapped resonator. In this paper, we examine a filter with an unbalanced port and a balanced port as well as a filter with a balanced port and a balanced port. The presented filters are simulated with commercial simulators and are measured with a vector network analyzer. We have confirmed that the bandpass characteristics with controllable attenuation poles and balanced characteristics(amplitude and phase balance performances) are obtained. The measured results of the fabricated filters agree well with the simulated results.

  8. Ring-Resonator/Sol-Gel Interferometric Immunosensor

    NASA Technical Reports Server (NTRS)

    Bearman, Gregory; Cohen, David

    2007-01-01

    A proposed biosensing system would be based on a combination of (1) a sensing volume containing antibodies immobilized in a sol-gel matrix and (2) an optical interferometer having a ring resonator configuration. The antibodies would be specific to an antigen species that one seeks to detect. In the ring resonator of the proposed system, light would make multiple passes through the sensing volume, affording greater interaction length and, hence, greater antibody- detection sensitivity.

  9. Investigation of New Microstrip Bandpass Filter Based on Patch Resonator with Geometrical Fractal Slot.

    PubMed

    Mezaal, Yaqeen S; Eyyuboglu, Halil T

    2016-01-01

    A compact dual-mode microstrip bandpass filter using geometrical slot is presented in this paper. The adopted geometrical slot is based on first iteration of Cantor square fractal curve. This filter has the benefits of possessing narrower and sharper frequency responses as compared to microstrip filters that use single mode resonators and traditional dual-mode square patch resonators. The filter has been modeled and demonstrated by Microwave Office EM simulator designed at a resonant frequency of 2 GHz using a substrate of εr = 10.8 and thickness of h = 1.27 mm. The output simulated results of the proposed filter exhibit 22 dB return loss, 0.1678 dB insertion loss and 12 MHz bandwidth in the passband region. In addition to the narrow band gained, miniaturization properties as well as weakened spurious frequency responses and blocked second harmonic frequency in out of band regions have been acquired. Filter parameters including insertion loss, return loss, bandwidth, coupling coefficient and external quality factor have been compared with different values of perturbation dimension (d). Also, a full comparative study of this filter as compared with traditional square patch filter has been considered.

  10. Investigation of New Microstrip Bandpass Filter Based on Patch Resonator with Geometrical Fractal Slot

    PubMed Central

    Mezaal, Yaqeen S.; Eyyuboglu, Halil T.

    2016-01-01

    A compact dual-mode microstrip bandpass filter using geometrical slot is presented in this paper. The adopted geometrical slot is based on first iteration of Cantor square fractal curve. This filter has the benefits of possessing narrower and sharper frequency responses as compared to microstrip filters that use single mode resonators and traditional dual-mode square patch resonators. The filter has been modeled and demonstrated by Microwave Office EM simulator designed at a resonant frequency of 2 GHz using a substrate of εr = 10.8 and thickness of h = 1.27 mm. The output simulated results of the proposed filter exhibit 22 dB return loss, 0.1678 dB insertion loss and 12 MHz bandwidth in the passband region. In addition to the narrow band gained, miniaturization properties as well as weakened spurious frequency responses and blocked second harmonic frequency in out of band regions have been acquired. Filter parameters including insertion loss, return loss, bandwidth, coupling coefficient and external quality factor have been compared with different values of perturbation dimension (d). Also, a full comparative study of this filter as compared with traditional square patch filter has been considered. PMID:27054755

  11. Resonant frequency of microstrip antennas calculated from TE-excitation of an infinite strip embedded in a grounded dielectric slab

    NASA Technical Reports Server (NTRS)

    Bailey, M. C.

    1979-01-01

    The calculation of currents induced by a plane wave normally incident upon an infinite strip embedded in a grounded dielectric slab is used to infer the resonant width (or frequency) of rectangular microstrip antennas. By placing the strip inside the dielectric, the effect of a dielectric cover of the same material as the substrate can be included in the calculation of resonant frequency. A comparison with measured results indicated agreement of 1 percent or better for rectangular microstrip antennas constructed on Teflon-fiberglass substrate.

  12. Clutter sensitivity test under controlled field conditions Resonant Microstrip Patch Antenna (RMPA) sensor technology

    SciTech Connect

    1996-06-27

    Theoretical research, controlled laboratory tests, and these field test results show that nonmetallic (and metallic) shallowly buried objects can be detected and imaged with the Resonant Microstrip Patch Antenna (RMPA) sensor. The sensor can be modeled as a high Q cavity which capitalizes on its resonant condition sensitivity to scattered waves from buried objects. When the RMPA sensor is swept over a shallowly buried object, the RMPA fed-point impedance (resistance), measured with a Maxwell bridge, changes by tens of percent. The significant change in unprocessed impedance data can be presented in two-dimensional and three-dimensional graphical displays over the survey area. This forms silhouette images of the objects without the application of computationally intensive data processing algorithms. Because RMPA employed electromagnetic waves to illuminate the shallowly buried object, a number of questions and issues arise in the decision to fund or deny funding of the reconfiguration of the RMPA technology into a nonmetallic (metallic) land mine detector.

  13. Ring Laser Gyro Resonator Design

    DTIC Science & Technology

    1994-06-20

    vibration environment could cause errors in measured RLG rotation rates due to vibration (tilt) of the resonator mirrors . Vibration-induced mirror tilt...the RLG resonator design theoretically and calculated pertinent parameters such as the beam diameter at the aperture, cavity mirror alignment...sensitivities, and power loss due to aperture occlusion. The mirror vibration levels required to significantly affect the laser power were then calculated for

  14. Tunable Superconducting Split Ring Resonators

    DTIC Science & Technology

    2012-09-19

    devices and the associated dissipative losses therein. This way an almost dissipationless active supercon- ducting circuit with magnetic control...capacitance of the gap to form a resonator circuit . The advantage of such a circuit is its quite low resonance frequency compared to other structures...of similar size. Figure 1: A schematic SSRR (left) and an equivalent circuit (right). C is the gap and surface capacitance, LGC is the magnetic

  15. Method and apparatus for magnetic resonance imaging and spectroscopy using microstrip transmission line coils

    DOEpatents

    Zhang, Xiaoliang; Ugurbil, Kamil; Chen, Wei

    2006-04-04

    Apparatus and method for MRI imaging using a coil constructed of microstrip transmission line (MTL coil) are disclosed. In one method, a target is positioned to be imaged within the field of a main magnetic field of a magnet resonance imaging (MRI) system, a MTL coil is positioned proximate the target, and a MRI image is obtained using the main magnet and the MTL coil. In another embodiment, the MRI coil is used for spectroscopy. MRI imaging and spectroscopy coils are formed using microstrip transmission line. These MTL coils have the advantageous property of good performance while occupying a relatively small space, thus allowing MTL coils to be used inside restricted areas more easily than some other prior art coils. In addition, the MTL coils are relatively simple to construct of inexpensive components and thus relatively inexpensive compared to other designs. Further, the MTL coils of the present invention can be readily formed in a wide variety of coil configurations, and used in a wide variety of ways. Further, while the MTL coils of the present invention work well at high field strengths and frequencies, they also work at low frequencies and in low field strengths as well.

  16. Chemical Sensors Based on Optical Ring Resonators

    NASA Technical Reports Server (NTRS)

    Homer, Margie; Manfreda, Allison; Mansour, Kamjou; Lin, Ying; Ksendzov, Alexander

    2005-01-01

    Chemical sensors based on optical ring resonators are undergoing development. A ring resonator according to this concept is a closed-circuit dielectric optical waveguide. The outermost layer of this waveguide, analogous to the optical cladding layer on an optical fiber, is a made of a polymer that (1) has an index of refraction lower than that of the waveguide core and (2) absorbs chemicals from the surrounding air. The index of refraction of the polymer changes with the concentration of absorbed chemical( s). The resonator is designed to operate with relatively strong evanescent-wave coupling between the outer polymer layer and the electromagnetic field propagating along the waveguide core. By virtue of this coupling, the chemically induced change in index of refraction of the polymer causes a measurable shift in the resonance peaks of the ring. In a prototype that has been used to demonstrate the feasibility of this sensor concept, the ring resonator is a dielectric optical waveguide laid out along a closed path resembling a racetrack (see Figure 1). The prototype was fabricated on a silicon substrate by use of standard techniques of thermal oxidation, chemical vapor deposition, photolithography, etching, and spin coating. The prototype resonator waveguide features an inner cladding of SiO2, a core of SixNy, and a chemical-sensing outer cladding of ethyl cellulose. In addition to the ring Chemical sensors based on optical ring resonators are undergoing development. A ring resonator according to this concept is a closed-circuit dielectric optical waveguide. The outermost layer of this waveguide, analogous to the optical cladding layer on an optical fiber, is a made of a polymer that (1) has an index of refraction lower than that of the waveguide core and (2) absorbs chemicals from the surrounding air. The index of refraction of the polymer changes with the concentration of absorbed chemical( s). The resonator is designed to operate with relatively strong

  17. Configurations of Splitter/Combiner Microstrip Sections Loaded with Stepped Impedance Resonators (SIRs) for Sensing Applications

    PubMed Central

    Su, Lijuan; Mata-Contreras, Javier; Vélez, Paris; Martín, Ferran

    2016-01-01

    In this paper, several configurations of splitter/combiner microstrip sections loaded with stepped impedance resonators (SIRs) are analyzed. Such structures are useful as sensors and comparators, and the main aim of the paper is to show that the proposed configurations are useful for the optimization of sensitivity and discrimination. Specifically, for comparison purposes, i.e., to determine anomalies, abnormalities or defects of a sample under test (SUT) in comparison to a reference sample, it is shown that up to three samples can be simultaneously tested. Simple models of the proposed structures are presented, and these models are validated through electromagnetic simulation and experiment. Finally, the principle of operation is validated through a proof-of-concept demonstrator. PMID:27999399

  18. Configurations of Splitter/Combiner Microstrip Sections Loaded with Stepped Impedance Resonators (SIRs) for Sensing Applications.

    PubMed

    Su, Lijuan; Mata-Contreras, Javier; Vélez, Paris; Martín, Ferran

    2016-12-20

    In this paper, several configurations of splitter/combiner microstrip sections loaded with stepped impedance resonators (SIRs) are analyzed. Such structures are useful as sensors and comparators, and the main aim of the paper is to show that the proposed configurations are useful for the optimization of sensitivity and discrimination. Specifically, for comparison purposes, i.e., to determine anomalies, abnormalities or defects of a sample under test (SUT) in comparison to a reference sample, it is shown that up to three samples can be simultaneously tested. Simple models of the proposed structures are presented, and these models are validated through electromagnetic simulation and experiment. Finally, the principle of operation is validated through a proof-of-concept demonstrator.

  19. DNA sensing using split-ring resonator alone at microwave regime

    NASA Astrophysics Data System (ADS)

    Lee, Hee-Jo; Lee, Hyun-Seok; Yoo, Kyung-Hwa; Yook, Jong-Gwan

    2010-07-01

    In this paper, the feasibility of utilization of a single element double split-ring resonator as a biosensing device has been demonstrated. The compact resonator has been excited by time-varying magnetic fields generated from the 50 Ω microstrip transmission line. In this work, DNA hybridization is recognized with shift in S21 resonant frequency. When thiol-linked single stranded-DNA is immobilized onto a gold (Au) surface and is then coupled with complementary-DNA, the frequency changes by Δfss-DNA=20 MHz and Δfhybridization=60 MHz, respectively. Thus, it is clear that the resonator can be utilized as a DNA sensing element in the microwave regime.

  20. An inverted-microstrip resonator for human head proton MR imaging at 7 tesla.

    PubMed

    Zhang, Xiaoliang; Ugurbil, Kamil; Sainati, Robert; Chen, Wei

    2005-03-01

    As an extension of the previously developed microstrip transmission line (MTL) RF coil design, a high-frequency RF volume coil using multiple inverted MTL (iMTL) resonators for human head imaging at high magnetic field strength of 7 tesla (T) is reported. Compared to conventional MTL resonators, iMTL resonators can operate at higher frequency with lower losses and, thus, are suitable for designs of high-frequency RF volume coils with large coil size for human MR imaging and spectroscopy at high fields. An approach using capacitive terminations was analyzed and applied to the design of the iMTL volume coil for improving RF field homogeneity and broadening frequency-tuning range. A performance-comparison study was conducted between the prototype iMTL volume coil and a custom-built TEM volume coil at 7 T. The iMTL volume coil presents a comparable SNR and intrinsic B1 homogeneity to the TEM volume coil. Phantom and the human head images acquired using the iMTL volume coil are also presented. The proposed iMTL volume coil provides an efficient and alternative solution to design high-frequency and large-size volume coils for human MR applications at very high fields.

  1. Ring waveguide resonator on surface acoustic waves

    NASA Astrophysics Data System (ADS)

    Biryukov, S. V.; Martin, G.; Weihnacht, M.

    2007-04-01

    A simple regular electrode structure for surface acoustic wave (SAW) devices is proposed. The structure consists of an interdigital transducer in the form of a ring placed on the Z cut of a hexagonal piezoelectric crystal. Finite thickness electrodes produce the known slowing effect for a SAW in comparison with this SAW on a free surface. The closed "slow" electrode region with the "fast" surrounding region forms an open waveguide resonator structure with the acoustic field concentrated in the electrode region. If the radius of the structure is large enough for a given wavelength, an acceptable level of radiation losses can be reached. The electrical admittance of such resonator does not have sidelobes.

  2. Coupling Between Split-Ring Resonators

    SciTech Connect

    Koenig, Michael; Stannigel, Kai; Niegemann, Jens; Busch, Kurt

    2009-10-07

    Numerical methods have become invaluable tools for research in the field of photonics and plasmonics. The Discontinuous Galerkin Time-Domain (DGTD) method, complemented by numerous extensions, allows us to solve Maxwell's equations on unstructured grids while maintaining an efficient, explicit time-stepping scheme. In this contribution we employ our DGTD computer code to analyse dimers of split-ring resonators (SRRs), metallic nano-structures often used as building blocks for metamaterials. We find that electromagnetic coupling between two SRRs heavily influences the dimers' resonances. Results for two SRRs facing each other are presented and the influence of the particle spacing is investigated.

  3. Reverse wave suppression in unstable ring resonator

    NASA Astrophysics Data System (ADS)

    Mirels, H.; Chodzko, R. A.; Bernard, J. M.; Giedt, R. R.; Coffer, J. G.

    1984-12-01

    Criteria for effective reverse-wave suppression (RWS) in CW and pulsed unstable ring lasers with inhomogeneously broadened media are determined theoretically, and the performance of a CW HF linear ring resonator (Chodzko et al., 1976) and of two configurations of a pulsed CO2 annular beam-rotation/internal-axicon (BRIA) resonator (Bullock et al., 1979) without and with an RWS mirror is evaluated experimentally. In the CW laser, the average forward-wave (FW) and RW power values are shown to be 61 and 39 W without RWS and 110 and 2.7 W with RWS, corresponding to a FW/RW power ratio of 41; in the pulsed BRIA lasers, power ratios of about 20 are achieved, but the RWS effectiveness is found to be highly sensitive to RWS-mirror and cavity misalignment. Graphs, drawings, tables, and photographs of typical waveforms are included.

  4. Automated synthesis of transmission lines loaded with complementary split ring resonators (CSRRs) and open complementary split ring resonators (OCSRRs) through aggressive space mapping (ASM)

    NASA Astrophysics Data System (ADS)

    Selga, Jordi; Rodríguez, Ana; Orellana, Marco; Boria, Vicente; Martín, Ferran

    2014-09-01

    This paper is focused on the application of space mapping optimization to the automated synthesis of transmission lines loaded with complementary split ring resonators (CSRRs) and open complementary split ring resonators (OCSRRs). These structures are of interest for the implementation of resonant-type metamaterial transmission lines and for the design of planar microwave circuits based on such complementary resonators. The paper presents a method to generate the layouts of CSRR- and OCSRR-loaded microstrip lines from the elements of their equivalent circuit models. Using the so-called aggressive space mapping, a specific implementation that uses quasi-Newton type iteration, we have developed synthesis algorithms that are able to provide the topology of these CSRR- and OCSRR-loaded lines in few steps. The most relevant aspect, however, is that this synthesis process is completely automatic, i.e., it does not require any action from the designers, other than initiating the algorithm. Moreover, this technique can be translated to other electrically small planar elements described by lumped element equivalent circuit models.

  5. Protein Sensors Based on Optical Ring Resonators

    NASA Technical Reports Server (NTRS)

    Lin, Ying; Ksendzov, Alexander

    2006-01-01

    Prototype transducers based on integrated optical ring resonators have been demonstrated to be useful for detecting the protein avidin in extremely dilute solutions. In an experiment, one of the transducers proved to be capable of indicating the presence of avidin at a concentration of as little as 300 pM in a buffer solution a detection sensitivity comparable to that achievable by previously reported protein-detection techniques. These transducers are serving as models for the further development of integrated-optics sensors for detecting small quantities of other proteins and protein-like substances. The basic principle of these transducers was described in Chemical Sensors Based on Optical Ring Resonators (NPO-40601), NASA Tech Briefs, Vol. 29, No. 10 (October 2005), page 32. The differences between the present transducers and the ones described in the cited prior article lie in details of implementation of the basic principle. As before, the resonator in a transducer of the present type is a closed-circuit dielectric optical waveguide. The outermost layer of this waveguide, analogous to the optical cladding layer on an optical fiber, consists of a layer comprising sublayers having indices of refraction lower than that of the waveguide core. The outermost sublayer absorbs the chemical of interest (in this case, avidin). The index of refraction of the outermost sublayer changes with the concentration of absorbed avidin. The resonator is designed to operate with relatively strong evanescent-wave coupling between the outer sublayer and the electromagnetic field propagating along the waveguide core. By virtue of this coupling, the chemically induced change in the index of refraction of the outermost sublayer causes a measurable change in the spectrum of the resonator output.

  6. Integrated micro ring resonator displacement sensor for scanning probe microscopies

    NASA Astrophysics Data System (ADS)

    Kiyat, Isa; Kocabas, Coskun; Aydinli, Atilla

    2004-03-01

    We describe a novel displacement sensor for scanning probe microscopies using an integrated optical micro ring resonator. This device operates by means of monitoring the changes in the transmission spectrum of a high finesse micro ring resonator. Finite element method simulations were carried out to obtain the optimum sensor design and finite difference time domain simulation was used to obtain the transfer characteristics of micro ring resonators. Operation principles and sensitivity calculations are discussed in detail. To achieve high sensitivity, we have studied different types of ring resonator. The highest sensitivity is obtained in a race-track resonator. This new design should provide sensitivities as high as ~10-4 Å-1.

  7. VUV optical ring resonator for Duke storage ring free electron laser

    SciTech Connect

    Park, S.H.; Litvinenko, V.N.; Madey, J.M.J.

    1995-12-31

    The conceptual design of the multifaceted-mirror ring resonator for Duke storage ring VUV FEL is presented. The expected performance of the OK-4 FEL with ring resonator is described. We discuss in this paper our plans to study reflectivity of VUV mirrors and their resistivity to soft X-ray spontaneous radiation from OK-4 undulator.

  8. Semiconductor single crystal external ring resonator cavity laser and gyroscope

    SciTech Connect

    Spitzer, M.P.

    1993-08-31

    A ring laser is described comprising: a semiconductor single crystal external ring resonator cavity having a plurality of reflecting surfaces defined by the planes of the crystal and establishing a closed optical path; and a discrete laser medium disposed in said semiconductor single crystal external ring resonator cavity for generating coherent light in said cavity, wherein said resonator cavity is decoupled from the laser medium.

  9. An Archetype Semi-Ring Fabry-Perot (SRFP) Resonator

    NASA Technical Reports Server (NTRS)

    Taghavi-Larigani, Shervin; VanZyl, Jakob

    2009-01-01

    We introduce and demonstrate the generation of a novel resonator, termed Semi-Ring Fabry-Perot (SRFP), that exhibits unique features, such as, its use of one plane mirror, allowing the SRFP to be easily fabricated as a symmetrical device. In addition to its unique features, it exhibits advantages of ring and Fabry-Perot resonators: 1) compared to a ring resonator that only allows a transmitted intensity, the Semi-Ring Fabry-Perot (SRFP) supports standing waves, allowing both a reflected and transmitted intensity; 2) the reflected light spectrum of the SRFP resonator is much narrower than similar Fabry-Perot, implying higher finesse.

  10. Swept frequency technique for dispersion measurement of microstrip lines

    NASA Technical Reports Server (NTRS)

    Lee, R. Q.

    1986-01-01

    Microstrip lines used in microwave integrated circuits are dispersive. Because a microstrip line is an open structure, the dispersion can not be derived with pure TEM, TE, or TM mode analysis. Dispersion analysis has commonly been done using a spectral domain approach, and dispersion measurement has been made with high Q microstrip ring resonators. Since the dispersion of a microstrip line is fully characterized by the frequency dependent phase velocity of the line, dispersion measurement of microstrip lines requires the measurement of the line wavelength as a function of frequency. In this paper, a swept frequency technique for dispersion measurement is described. The measurement was made using an automatic network analyzer with the microstrip line terminated in a short circuit. Experimental data for two microstrip lines on 10 and 30 mil Cuflon substrates were recorded over a frequency range of 2 to 20 GHz. Agreement with theoretical results computed by the spectral domain approach is good. Possible sources of error for the discrepancy are discussed.

  11. Differential Resonant Ring YIG Tuned Oscillator

    NASA Technical Reports Server (NTRS)

    Parrott, Ronald A.

    2010-01-01

    A differential SiGe oscillator circuit uses a resonant ring-oscillator topology in order to electronically tune the oscillator over multi-octave bandwidths. The oscillator s tuning is extremely linear, because the oscillator s frequency depends on the magnetic tuning of a YIG sphere, whose resonant frequency is equal to a fundamental constant times the DC magnetic field. This extremely simple circuit topology uses two coupling loops connecting a differential pair of SiGe bipolar transistors into a feedback configuration using a YIG tuned filter creating a closed-loop ring oscillator. SiGe device technology is used for this oscillator in order to keep the transistor s 1/f noise to an absolute minimum in order to achieve minimum RF phase noise. The single-end resonant ring oscillator currently has an advantage in fewer parts, but when the oscillation frequency is greater than 16 GHz, the package s parasitic behavior couples energy to the sphere and causes holes and poor phase noise performance. This is because the coupling to the YIG is extremely low, so that the oscillator operates at near the unloaded Q. With the differential resonant ring oscillator, the oscillation currents are just in the YIG coupling mechanisms. The phase noise is even better, and the physical size can be reduced to permit monolithic microwave integrated circuit oscillators. This invention is a YIG tuned oscillator circuit making use of a differential topology to simultaneously achieve an extremely broadband electronic tuning range and ultra-low phase noise. As a natural result of its differential circuit topology, all reactive elements, such as tuning stubs, which limit tuning bandwidth by contributing excessive open loop phase shift, have been eliminated. The differential oscillator s open-loop phase shift is associated with completely non-dispersive circuit elements such as the physical angle of the coupling loops, a differential loop crossover, and the high-frequency phase shift of the n

  12. Mode Orientation Control For Sapphire Dielectric Ring Resonator

    NASA Technical Reports Server (NTRS)

    Santiago, David G.; Dick, G. John; Prata, Aluizio

    1996-01-01

    Small sapphire tuning wedge used in technique for solving mode-purity problem associated with sapphire dielectric-ring resonator part of cryogenic microwave frequency discriminator. Breaks quasi-degeneracy of two modes and allows selective coupling to just one mode. Wedge mounted on axle entering resonator cavity and rotated while resonator cryogenically operating in vacuum. Furthermore, axle moved vertically to tune resonant frequency.

  13. A compact 5.5 GHz band-rejected UWB antenna using complementary split ring resonators.

    PubMed

    Islam, M M; Faruque, M R I; Islam, M T

    2014-01-01

    A band-removal property employing microwave frequencies using complementary split ring resonators (CSRRs) is applied to design a compact UWB antenna wishing for the rejection of some frequency band, which is meanwhile exercised by the existing wireless applications. The reported antenna comprises optimization of a circular radiating patch, in which slotted complementary SRRs are implanted. It is printed on low dielectric FR4 substrate material fed by a partial ground plane and a microstrip line. Validated results exhibit that the reported antenna shows a wide bandwidth covering from 3.45 to more than 12 GHz, with a compact dimension of 22 × 26 mm(2), and VSWR < 2, observing band elimination of 5.5 GHz WLAN band.

  14. A Compact 5.5 GHz Band-Rejected UWB Antenna Using Complementary Split Ring Resonators

    PubMed Central

    Islam, M. M.; Faruque, M. R. I.; Islam, M. T.

    2014-01-01

    A band-removal property employing microwave frequencies using complementary split ring resonators (CSRRs) is applied to design a compact UWB antenna wishing for the rejection of some frequency band, which is meanwhile exercised by the existing wireless applications. The reported antenna comprises optimization of a circular radiating patch, in which slotted complementary SRRs are implanted. It is printed on low dielectric FR4 substrate material fed by a partial ground plane and a microstrip line. Validated results exhibit that the reported antenna shows a wide bandwidth covering from 3.45 to more than 12 GHz, with a compact dimension of 22 × 26 mm2, and VSWR < 2, observing band elimination of 5.5 GHz WLAN band. PMID:24971379

  15. Analysis and design of ring-resonator integrated hemi-elliptical lens antenna at terahertz frequency

    NASA Astrophysics Data System (ADS)

    Jha, Kumud Ranjan; Singh, G.

    2012-07-01

    In this paper, a novel lens integrated ring-resonator microstrip antenna is analyzed and simulated at 600 GHz. A mathematical model to compute the directivity of this kind of the antenna has been developed and the directivity of the antenna has been computed which is 18 dBi. The proposed model has been simulated by using CST Microwave Studio a commercially available simulator based on finite integral technique and similar result has been obtained. Further, the directivity of the antenna has also been computed by using the techniques reported in the literature and in this case also we have obtained the similar result. Later, a probe-fed patch integrated lens antenna has also been investigated to validate the correctness of the numerical method. To find the potential advantages of this kind of the structure, the - 10 dB impedance bandwidth of the antenna has been compared to a lens-integrated probe-fed microstrip patch antenna and a significant enhancement in the bandwidth has been observed.

  16. Design and implementation of dual-band antennas based on a complementary split ring resonators

    NASA Astrophysics Data System (ADS)

    Ortiz, Noelia; Iriarte, Juan Carlos; Crespo, Gonzalo; Falcone, Francisco

    2015-07-01

    A simple dual-band antenna design and implementation method is proposed in this work, based on the equivalent media properties inspired by resonant metamaterial elements. The equivalent circuit model of dual-band patch antennas based on a complementary split ring resonator (CSRR) is presented and validated. The dual-band patch antenna is designed etching a CSRR in the patch of a conventional rectangular microstrip patch antenna. The first resonance is governed by the quasi-static resonance of the CSRR while the second resonance is originated by the rectangular patch. The fact of etching a CSRR on a rectangular patch antenna also produces a miniaturization of a conventional patch antenna. The equivalent circuit model proposed in this letter is sound in order to understand the functionality of dual-band patch antennas based on a CSRR. Good agreement between simulation, equivalent circuit model and experimental results is shown and discussed. These results lead the equivalent circuit model to become a simple and straightforward tool for the design of this type of multiband antennas, of low cost and versatile operation for a broad range of wireless communication systems.

  17. Digital crossbar switch using nonlinear optical ring resonator

    NASA Astrophysics Data System (ADS)

    McAulay, Alastair D.

    2009-08-01

    Optical elements are preferred to electronic ones for military computing and communications to reduce vulnerability to electromagnetic pulses from nuclear explosion, electromagnetic bombs or lightning. Equations are derived for an optical micro ring resonator and for a nonlinear ring resonator that uses Kerr material so that the resonant frequency changes with light intensity in the ring. The switch can be modulated at faster than 10 Gbps for compatibility with electronic switches and equipment. A two-by-two switch is described based on the nonlinear ring resonator. A Benes network is constructed using the two-by-two switches. This allows full permutations of the inputs by means of an algorithm for setting the switches. Several rings are used for each frequency with slightly different frequencies to allow switching of wavelength division multiplexed signals.

  18. 225-255-GHz InP DHBT Frequency Tripler MMIC Using Complementary Split-Ring Resonator

    NASA Astrophysics Data System (ADS)

    Li, Xiao; Zhang, Yong; Li, Oupeng; Sun, Yan; Lu, Haiyan; Cheng, Wei; Xu, Ruimin

    2017-02-01

    In this paper, a novel design of frequency tripler monolithic microwave integrated circuit (MMIC) using complementary split-ring resonator (CSRR) is proposed based on 0.5-μm InP DHBT process. The CSRR-loaded microstrip structure is integrated in the tripler as a part of impedance matching network to suppress the fundamental harmonic, and another frequency tripler based on conventional band-pass filter is presented for comparison. The frequency tripler based on CSRR-loaded microstrip generates an output power between -8 and -4 dBm from 228 to 255 GHz when the input power is 6 dBm. The suppression of fundamental harmonic is better than 20 dBc at 77-82 GHz input frequency within only 0.15 × 0.15 mm2 chip area of the CSRR structure on the ground layer. Compared with the frequency tripler based on band-pass filter, the tripler using CSRR-loaded microstrip obtains a similar suppression level of unwanted harmonics and higher conversion gain within a much smaller chip area. To our best knowledge, it is the first time that CSRR is used for harmonic suppression of frequency multiplier at such high frequency band.

  19. Analysis of rectangular microstrip antennas

    NASA Technical Reports Server (NTRS)

    Bailey, M. C.; Deshpande, M. D.

    1984-01-01

    The problem of microstrip antennas covered by a dielectric substrate is formulated in terms of coupled integro-differential equations with the current distribution on the conducting patch as an unknown quantity. The Galerkin method is used to solve for the unknown patch current. Using the present formulation, the radiation pattern, the resonant frequency, and the bandwidth of a rectangular microstrip antenna are computed. Design data for a rectangular microstrip antenna are also presented.

  20. An Aligned-Gap and Centered-Gap Rectangular Multiple Split Ring Resonator for dielectric sensing applications.

    PubMed

    Rusni, Izyani Mat; Ismail, Alyani; Alhawari, Adam Reda Hasan; Hamidon, Mohd Nizar; Yusof, Nor Azah

    2014-07-21

    This paper presents the design and development of a planar Aligned-Gap and Centered-Gap Rectangular Multiple Split Ring Resonator (SRR) for microwave sensors that operates at a resonance frequency around 5 GHz. The sensor consists of a microstrip transmission line loaded with two elements of rectangular SRR on both sides. The proposed metamaterial sensors were designed and fabricated on Rogers RT5880 substrate having dielectric constant of 2.2 and thickness of 0.787 mm. The final dimension of the proposed sensor was measured at 35 × 14 mm2. Measured results show good agreement with simulated ones as well as exhibiting high Q-factor for use in sensing application. A remarkably shift of resonance frequency is observed upon introduction of several sample with different dielectric value.

  1. An Aligned-Gap and Centered-Gap Rectangular Multiple Split Ring Resonator for Dielectric Sensing Applications

    PubMed Central

    Rusni, Izyani Mat; Ismail, Alyani; Alhawari, Adam Reda Hasan; Hamidon, Mohd Nizar; Yusof, Nor Azah

    2014-01-01

    This paper presents the design and development of a planar Aligned-Gap and Centered-Gap Rectangular Multiple Split Ring Resonator (SRR) for microwave sensors that operates at a resonance frequency around 5 GHz. The sensor consists of a microstrip transmission line loaded with two elements of rectangular SRR on both sides. The proposed metamaterial sensors were designed and fabricated on Rogers RT5880 substrate having dielectric constant of 2.2 and thickness of 0.787 mm. The final dimension of the proposed sensor was measured at 35 × 14 mm2. Measured results show good agreement with simulated ones as well as exhibiting high Q-factor for use in sensing application. A remarkably shift of resonance frequency is observed upon introduction of several sample with different dielectric value. PMID:25051036

  2. Ten Ghz YBa2Cu3O(7-Delta) Superconducting Ring Resonators on NdGaO3 Substrates

    NASA Technical Reports Server (NTRS)

    To, H. Y.; Valco, G. J.; Bhasin, K. B.

    1993-01-01

    YBa2Cu3O(7-delta) thin films were formed on NdGaO3 substrates by laser ablation. Critical temperatures greater than 89 K and critical current densities exceeding 2 x 10(exp 8) Acm(sub -2) at 77 K were obtained. The microwave performance of films patterned into microstrip ring resonators with gold ground planes was measured. An unloaded quality factor six times larger than that of a gold resonator of identical geometry was achieved. The unloaded quality factor decreased below 70 K for both the superconducting and gold resonators due to increasing dielectric losses in the substrate. The temperature dependence of the loss tangent of NdGaO3 was extracted from the measurements.

  3. Porous silicon ring resonator for compact, high sensitivity biosensing applications

    DOE PAGES

    Rodriguez, Gilberto A.; Hu, Shuren; Weiss, Sharon M.

    2015-01-01

    A ring resonator is patterned on a porous silicon slab waveguide to produce a compact, high quality factor biosensor with a large internal surface area available for enhanced recognition of biological and chemical molecules. The porous nature of the ring resonator allows molecules to directly interact with the guided mode. Quality factors near 10,000 were measured for porous silicon ring resonators with a radius of 25 μm. A bulk detection sensitivity of 380 nm/RIU was measured upon exposure to salt water solutions. Specific detection of nucleic acid molecules was demonstrated with a surface detection sensitivity of 4 pm/nM.

  4. Ring resonator based narrow-linewidth semiconductor lasers

    NASA Technical Reports Server (NTRS)

    Ksendzov, Alexander (Inventor)

    2005-01-01

    The present invention is a method and apparatus for using ring resonators to produce narrow linewidth hybrid semiconductor lasers. According to one embodiment of the present invention, the narrow linewidths are produced by combining the semiconductor gain chip with a narrow pass band external feedback element. The semi conductor laser is produced using a ring resonator which, combined with a Bragg grating, acts as the external feedback element. According to another embodiment of the present invention, the proposed integrated optics ring resonator is based on plasma enhanced chemical vapor deposition (PECVD) SiO.sub.2 /SiON/SiO.sub.2 waveguide technology.

  5. Dynamic nonlinear thermal optical effects in coupled ring resonators

    NASA Astrophysics Data System (ADS)

    Huang, Chenguang; Fan, Jiahua; Zhu, Lin

    2012-09-01

    We investigate the dynamic nonlinear thermal optical effects in a photonic system of two coupled ring resonators. A bus waveguide is used to couple light in and out of one of the coupled resonators. Based on the coupling from the bus to the resonator, the coupling between the resonators and the intrinsic loss of each individual resonator, the system transmission spectrum can be classified by three different categories: coupled-resonator-induced absorption, coupled-resonator-induced transparency and over coupled resonance splitting. Dynamic thermal optical effects due to linear absorption have been analyzed for each category as a function of the input power. The heat power in each resonator determines the thermal dynamics in this coupled resonator system. Multiple "shark fins" and power competition between resonators can be foreseen. Also, the nonlinear absorption induced thermal effects have been discussed.

  6. Modeling a Large Ring Resonator Gyroscope.

    DTIC Science & Technology

    2014-09-26

    quantum noise and low frequency noise b) Basic modeling of the ring with Gaussian beam and ray matrices c) Technical design: Effect of residual gas in...ring on quality factor and light drag, scanning of beam, effect of misalignment and mismatch of source to ring, calibration procedures. The results show...Frequencies of Hermite-Gaussian modes in a ringlaser 64 II. F. Injection errors: Misalignment and mismatching of an injected 77 Gaussian beam. Effects of offset

  7. Asymmetric split ring resonators for optical sensing of organic materials.

    PubMed

    Lahiri, Basudev; Khokhar, Ali Z; De La Rue, Richard M; McMeekin, Scott G; Johnson, Nigel P

    2009-01-19

    Asymmetric Split Ring Resonators are known to exhibit resonant modes where the optical electric field is strongest near the ends of the arms, thereby increasing the sensitivity of spectral techniques such as surface enhanced Raman scattering (SERS). By producing asymmetry in the structures, the two arms of the ring produce distinct plasmonic resonances related to their lengths - but are also affected by the presence of the other arm. This combination leads to a steepening of the slope of the reflection spectrum between the resonances that increases the sensitivity of the resonant behavior to the addition of different molecular species. We describe experimental results, supported by simulation, on the resonances of a series of circular split ring resonators with different gap and section lengths--at wavelengths in the mid-infra red regions of the spectrum--and their utilization for highly sensitive detection of organic compounds. We have used thin films of PMMA with different thicknesses, resulting in characteristic shifts from the original resonance. We also demonstrate matching of asymmetric split ring resonators to a molecular resonance of PMMA.

  8. Monolithic optofluidic ring resonator lasers created by femtosecond laser nanofabrication.

    PubMed

    Chandrahalim, Hengky; Chen, Qiushu; Said, Ali A; Dugan, Mark; Fan, Xudong

    2015-05-21

    We designed, fabricated, and characterized a monolithically integrated optofluidic ring resonator laser that is mechanically, thermally, and chemically robust. The entire device, including the ring resonator channel and sample delivery microfluidics, was created in a block of fused-silica glass using a 3-dimensional femtosecond laser writing process. The gain medium, composed of Rhodamine 6G (R6G) dissolved in quinoline, was flowed through the ring resonator. Lasing was achieved at a pump threshold of approximately 15 μJ mm(-2). Detailed analysis shows that the Q-factor of the optofluidic ring resonator is 3.3 × 10(4), which is limited by both solvent absorption and scattering loss. In particular, a Q-factor resulting from the scattering loss can be as high as 4.2 × 10(4), suggesting the feasibility of using a femtosecond laser to create high quality optical cavities.

  9. Waveguide ring resonator as integrated optics for rotation sensor

    NASA Astrophysics Data System (ADS)

    Tang, Quan'an; Zheng, Ludi; Ma, Xinyu; Zhang, Yanshen

    1996-09-01

    To obtain a micro optic rotation sensor (MORS), a passive ring resonator (PRR) based on channel waveguide was designed and investigated. The waveguide structure of the resonator includes a ring waveguide as well as two directional couplers. The theoretical resolution and transfer functions of the MORS are discussed, and the PRR parameters are determined. According to the sensitivity requirement, the PRR frequency detecting system is discussed, and different detecting schemes are compared.

  10. Preparation of ring resonator based on PDMS using laser lithography

    NASA Astrophysics Data System (ADS)

    Jandura, D.; Pudis, D.; Gaso, P.

    2016-12-01

    In this paper we present preparation process of ring resonator in racetrack configuration based on polydimethylsiloxane (PDMS). 3D laser lithography in combination with imprinting technique was used to pattern photoresist layer as a master for imprinting process. In the next step, PDMS ring resonator was imprinted and filled with core PDMS. Finally, morphological properties of prepared device were investigated by scanning electron microscope (SEM) and confocal microscope and transmission spectrum measurements were performed.

  11. Analysis of Double Ring Resonators using Method of Equating Fields

    NASA Astrophysics Data System (ADS)

    Althaf, Shahana

    Optical ring resonators have the potential to be integral parts of large scale photonic circuits. My thesis theoretically analyzes parallel coupled double ring resonators (DRRs) in detail. The analysis is performed using the method of equating fields (MEF) which provides an in depth understanding about the transmitted and reflected light paths in the structure. Equations for the transmitted and reflected fields are derived; these equations allow for unequal ring lengths and coupling coefficients. Sanity checks including comparison with previously studied structures are performed in the final chapter in order to prove the correctness of the obtained results.

  12. High quality factor etchless silicon photonic ring resonators.

    PubMed

    Luo, Lian-Wee; Wiederhecker, Gustavo S; Cardenas, Jaime; Poitras, Carl; Lipson, Michal

    2011-03-28

    We demonstrate high quality factor etchless silicon photonic ring resonators fabricated by selective thermal oxidation of silicon without the silicon layer being exposed to any plasma etching throughout the fabrication process. We achieve a high intrinsic quality factor of 510,000 in 50 µm-radius ring resonators, corresponding to a ring loss of 0.8 dB/cm. The device has a total chip insertion loss of 2.5 dB, achieved by designing etchless silicon inverse nanotapers at both the input and output of the chip.

  13. MEMS tunable optical filter based on multi-ring resonator

    SciTech Connect

    Dessalegn, Hailu E-mail: tsrinu@ece.iisc.ernet.in; Srinivas, T. E-mail: tsrinu@ece.iisc.ernet.in

    2014-10-15

    We propose a novel MEMS tunable optical filter with a flat-top pass band based on multi-ring resonator in an electrostatically actuated microcantilever for communication application. The filter is basically structured on a microcantilever beam and built in optical integrated ring resonator which is placed in one end of the beam to gain maximum stress on the resonator. Thus, when a DC voltage is applied, the beam will bend, that induces a stress and strain in the ring, which brings a change in refractive index and perimeter of the rings leading to change in the output spectrum shift, providing the tenability as high as 0.68nm/μN and it is capable of tuning up to 1.7nm.

  14. Rings of Uranus as resonances with unseen satellites

    SciTech Connect

    Gorkavyi, N.N.; Fridman, A.M.

    1985-10-01

    The pattern of rings in the Uranus system is described, and previous hypothesis seeking to explain that pattern are reviewed. It is proposed that the ring pattern is produced by resonances from five undiscovered satellites located beyond the outer boundary of the rings. The satellite orbit radii would be 66,450, 62,470, 58,600, 55,380, and 51,580 km. This hypothesis is supported by the clearly nonrandom placement of the rings, enabling an accurate determination of the presumed satellite orbits. 12 references.

  15. Experimental study of resonance fiber optic gyroscope employing a dual-ring resonator

    NASA Astrophysics Data System (ADS)

    Fan, Yue; Wang, Wei

    2016-09-01

    A dual-ring resonator which is available to alter the full width at half maximum (FWHM) without altering the free spectrum range (FSR) for practice applications is analyzed theoretically and set up in practice. The parameters of the dual-ring resonator have been optimized in simulation, the resonance depth and the dynamic range are enhanced. The prototype is set up with single mode fiber of 8 meter and two 95 : 5 couplers for open loop experiment. The FWHM of the dual-ring resonator is demonstrated less than 1.5MHz and the fineness is calculated to be 37 during the frequency sweeping experiment. The frequency locking experiment with demodulation curve method has been accomplished, and the locking time achieves less than 40ms. All these provide a basic reference for optimizing the resonance fiber optic gyro based on dual-ring resonator.

  16. High performance patch antenna using circular split ring resonators and thin wires employing electromagnetic coupling improvement

    NASA Astrophysics Data System (ADS)

    Abdelrehim, Adel A. A.; Ghafouri-Shiraz, H.

    2016-09-01

    In this paper, three dimensional periodic structure composed of circular split ring resonators and thin wires is used to improve the performance of a microstrip patch antenna. The three dimensional periodic structure is placed at the top of the patch within a specific separation distance to construct the proposed antenna. The radiated electromagnetic waves intensity of the proposed antenna is improved compared with the conventional patch antenna due to the electric and magnetic coupling enhancements. These enhancements occur between the patch and the periodic structure resonators and between the different resonator pairs of the periodic structure. As a result, the electric and the magnetic fields at the top of the patch are improved, the radiated electromagnetic beam size reduces which results in a highly focused beam and hence the antenna directivity and gain are improved, while the beam are is reduced. The proposed antenna has been designed and simulated using CST microwave studio at 10 GHz. An infinite two dimensional periodicity unit cell of circular split ring resonator and thin wire is designed to resonate at a 10 GHz and simulated in CST software, the scattering parameters are extracted, the results showed that the infinite periodicity two dimensional structure has a pass band frequency response of good transmission and reflection characteristics around 10 GHz. The infinite periodicity of the two dimensional periodic structure is then truncated and multi layers of such truncated structure is used to construct a three dimensional periodic structure. A parametric analysis has been performed on the proposed antenna incorporated with the three dimensional periodic structure. The impacts of the separation distance between the patch and three dimensional periodic structures and the size of the three dimensional periodic structure on the radiation and impedance matching parameters of the proposed antenna are studied. For experimental verification, the proposed

  17. Nonlinear ring resonator: spatial pattern generation

    NASA Astrophysics Data System (ADS)

    Ivanov, Vladimir Y.; Lachinova, Svetlana L.; Irochnikov, Nikita G.

    2000-03-01

    We consider theoretically spatial pattern formation processes in a unidirectional ring cavity with thin layer of Kerr-type nonlinear medium. Our method is based on studying of two coupled equations. The first is a partial differential equation for temporal dynamics of phase modulation of light wave in the medium. It describes nonlinear interaction in the Kerr-type lice. The second is a free propagation equation for the intracavity field complex amplitude. It involves diffraction effects of light wave in the cavity.

  18. Antiferromagnetic resonance excitation by terahertz magnetic field resonantly enhanced with split ring resonator

    SciTech Connect

    Mukai, Y.; Hirori, H.; Yamamoto, T.; Kageyama, H.; Tanaka, K.

    2014-07-14

    Excitation of antiferromagnetic resonance (AFMR) in a HoFeO{sub 3} crystal combined with a split ring resonator (SRR) is studied using terahertz (THz) electromagnetic pulses. The magnetic field in the vicinity of the SRR is induced by the incident THz electric field component and excites spin oscillations that correspond to the AFMR, which are directly probed by the Faraday rotation of the polarization of a near-infrared probe pulse. The good agreement of the temperature-dependent magnetization dynamics with the calculation using the two-lattice Landau-Lifshitz-Gilbert equation confirms that the AFMR is excited by the THz magnetic field, which is enhanced at the SRR resonance frequency by a factor of 20 compared to the incident magnetic field.

  19. Fano resonances in a multimode waveguide coupled to a high-Q silicon nitride ring resonator.

    PubMed

    Ding, Dapeng; de Dood, Michiel J A; Bauters, Jared F; Heck, Martijn J R; Bowers, John E; Bouwmeester, Dirk

    2014-03-24

    Silicon nitride (Si3N4) optical ring resonators provide exceptional opportunities for low-loss integrated optics. Here we study the transmission through a multimode waveguide coupled to a Si3N4 ring resonator. By coupling single-mode fibers to both input and output ports of the waveguide we selectively excite and probe combinations of modes in the waveguide. Strong asymmetric Fano resonances are observed and the degree of asymmetry can be tuned through the positions of the input and output fibers. The Fano resonance results from the interference between modes of the waveguide and light that couples resonantly to the ring resonator. We develop a theoretical model based on the coupled mode theory to describe the experimental results. The large extension of the optical modes out of the Si3N4 core makes this system promising for sensing applications.

  20. Ultrasonic Resonance Spectroscopy of Composite Rings for Flywheel Rotors

    NASA Technical Reports Server (NTRS)

    Harmon, Laura M.; Baaklini, George Y.

    2001-01-01

    Flywheel energy storage devices comprising multilayered composite rotor systems are being studied extensively for utilization in the International Space Station. These composite material systems were investigated with a recently developed ultrasonic resonance spectroscopy technique. The system employs a swept frequency approach and performs a fast Fourier transform on the frequency spectrum of the response signal. In addition. the system allows for equalization of the frequency spectrum, providing all frequencies with equal amounts of energy to excite higher order resonant harmonics. Interpretation of the second fast Fourier transform, along with equalization of the frequency spectrum, offers greater assurance in acquiring and analyzing the fundamental frequency, or spectrum resonance spacing. The range of frequencies swept in a pitch-catch mode was varied up to 8 MHz, depending on the material and geometry of the component. Single and multilayered material samples, with and without known defects, were evaluated to determine how the constituents of a composite material system affect the resonant frequency. Amplitude and frequency changes in the spectrum and spectrum resonance spacing domains were examined from ultrasonic responses of a flat composite coupon, thin composite rings, and thick composite rings. Also, the ultrasonic spectroscopy responses from areas with an intentional delamination and a foreign material insert, similar to defects that may occur during manufacturing malfunctions, were compared with those from defect-free areas in thin composite rings. A thick composite ring with varying thickness was tested to investigate the full-thickness resonant frequency and any possible bulk interfacial bond issues. Finally, the effect on the frequency response of naturally occurring single and clustered voids in a composite ring was established.

  1. Electrodynamics of a ring-shaped spiral resonator

    NASA Astrophysics Data System (ADS)

    Maleeva, N.; Fistul, M. V.; Karpov, A.; Zhuravel, A. P.; Averkin, A.; Jung, P.; Ustinov, A. V.

    2014-02-01

    We present analytical, numerical, and experimental investigations of electromagnetic resonant modes of a compact monofilar Archimedean spiral resonator shaped in a ring, with no central part. Planar spiral resonators are interesting as components of metamaterials for their compact deep-subwavelength size. Such resonators couple primarily to the magnetic field component of the incident electromagnetic wave, offering properties suitable for magnetic meta-atoms. Surprisingly, the relative frequencies of the resonant modes follow the sequence of the odd numbers as f1:f2:f3:f4… = 1:3:5:7…, despite the nearly identical boundary conditions for electromagnetic fields at the extremities of the resonator. In order to explain the observed spectrum of resonant modes, we show that the current distribution inside the spiral satisfies a particular Carleman type singular integral equation. By solving this equation, we obtain a set of resonant frequencies. The analytically calculated resonance frequencies and the current distributions are in good agreement with experimental data and the results of numerical simulations. By using low-temperature laser scanning microscopy of a superconducting spiral resonator, we compare the experimentally visualized ac current distributions over the spiral with the calculated ones. Theory and experiment agree well with each other. Our analytical model allows for calculation of a detailed three-dimensional magnetic field structure of the resonators.

  2. Detection of surface and subsurface cracks in metallic and non-metallic materials using a complementary split-ring resonator.

    PubMed

    Albishi, Ali; Ramahi, Omar M

    2014-10-16

    Available microwave techniques for crack detection have some challenges, such as design complexity and working at a high frequency. These challenges make the sensing apparatus design complex and relatively very expensive. This paper presents a simple method for surface and subsurface crack detection in metallic and non-metallic materials based on complementary split-ring resonators (CSRRs). A CSRR sensor can be patterned on the ground plane of a microstrip line and fabricated using printed circuit board technology. Compared to available microwave techniques for sub-millimeter crack detection, the methods presented here show distinct advantages, such as high spatial resolution, high sensitivity and design simplicity. The response of the CSRR as a sensor for crack detection is studied and analysed numerically. Experimental validations are also presented.

  3. Detection of Surface and Subsurface Cracks in Metallic and Non-Metallic Materials Using a Complementary Split-Ring Resonator

    PubMed Central

    Albishi, Ali; Ramahi, Omar M.

    2014-01-01

    Available microwave techniques for crack detection have some challenges, such as design complexity and working at a high frequency. These challenges make the sensing apparatus design complex and relatively very expensive. This paper presents a simple method for surface and subsurface crack detection in metallic and non-metallic materials based on complementary split-ring resonators (CSRRs). A CSRR sensor can be patterned on the ground plane of a microstrip line and fabricated using printed circuit board technology. Compared to available microwave techniques for sub-millimeter crack detection, the methods presented here show distinct advantages, such as high spatial resolution, high sensitivity and design simplicity. The response of the CSRR as a sensor for crack detection is studied and analysed numerically. Experimental validations are also presented. PMID:25325340

  4. Progress On 58m2 Passive Resonant Ring Laser Gyroscope

    NASA Astrophysics Data System (ADS)

    Shaw, G. L.; Rotge, J.; Simmons, B. J.

    1986-01-01

    An update of the large area (now 60m2) Passive Resonant Ring Laser Gyro (PRRLG) is given. Some aspects of last year's design have changed; but performance is still predicted to be in the 10-10 earth rate unit (ERU) range. This is of interest for a number of geophysical applications.

  5. Thomson’s ring experiment with resonant LC circuit

    NASA Astrophysics Data System (ADS)

    Haidar, Sajjad

    2016-01-01

    Thomson’s jumping ring experiment is conducted using a low voltage (24 V) electronic circuit. A coil (L) is connected with a capacitor (C) in parallel and is driven at its resonant frequency to obtain a high current in the coil. A circuit sends current pulses to the LC tank circuit at around its resonant frequency. The oscillating current in the coil induces a voltage in a copper-loop on top of it. The induced current interacts with the radial part of the coil-magnetic field; the resulting force levitates the loop. In a separate coil, a ferrite core and a copper ring are used to demonstrate the jumping-ring effect. The levitation and the jumping effect can be controlled by changing the duty cycle and frequency. In this report simple formulae and approximations are used to calculate the levitating force on the loop.

  6. Complex permittivity measurement using metamaterial split ring resonators

    NASA Astrophysics Data System (ADS)

    Chakyar, Sreedevi P.; Simon, Sikha K.; Bindu, C.; Andrews, Jolly; Joseph, V. P.

    2017-02-01

    A direct and efficient method for determining the complex permittivity of materials at microwave frequencies using a Split Ring Resonator (SRR) metamaterial structure is presented. A single SRR unit fabricated on a substrate arranged between transmitting and receiving probes acts as a test probe. Dielectric samples having at least one flat surface of area greater than or equal to the area of SRR structure are used as test samples. The relative permittivity and the loss tangent of the dielectric are evaluated from the resonant frequency shift and the bandwidth of the SRR resonator, by placing the sample over it. The LC resonance of the SRR test probe is theoretically related to the permittivity by considering its equivalent circuit in terms of the dielectric filled capacitances formed on the upper and lower surfaces of the SRR. The permittivity measurements are performed using test probes of different resonant frequencies, and the results are compared with the values obtained by the cavity perturbation method.

  7. Damping of Resonantly Forced Density Waves in Dense Planetary Rings

    NASA Astrophysics Data System (ADS)

    Lehmann, Marius; Schmidt, Jürgen; Salo, Heikki

    2016-10-01

    We address the stability of resonantly forced density waves in dense planetary rings.Already by Goldreich and Tremaine (1978) it has been argued that density waves might be unstable, depending on the relationship between the ring's viscosity and the surface mass density. In the recent paper (Schmidt et al. 2016) we have pointed out that when - within a fluid description of the ring dynamics - the criterion for viscous overstability is satisfied, forced spiral density waves become unstable as well. In this case, linear theory fails to describe the damping.We apply the multiple scale formalism to derive a weakly nonlinear damping relation from a hydrodynamical model.This relation describes the resonant excitation and nonlinear viscous damping of spiral density waves in a vertically integrated fluid disk with density dependent transport coefficients. The model consistently predicts linear instability of density waves in a ring region where the conditions for viscous overstability are met. In this case, sufficiently far away from the Lindblad resonance, the surface mass density perturbation is predicted to saturate to a constant value due to nonlinear viscous damping. In general the model wave damping lengths depend on a set of input parameters, such as the distance to the threshold for viscous overstability and the ground state surface mass density.Our new model compares reasonably well with the streamline model for nonlinear density waves of Borderies et al. 1986.Deviations become substantial in the highly nonlinear regime, corresponding to strong satellite forcing.Nevertheless, we generally observe good or at least qualitative agreement between the wave amplitude profiles of both models. The streamline approach is superior at matching the total wave profile of waves observed in Saturn's rings, while our new damping relation is a comparably handy tool to gain insight in the evolution of the wave amplitude with distance from resonance, and the different regimes of

  8. The microstrip filters based on electromagnetic crystal of resonators 2d disposition

    NASA Astrophysics Data System (ADS)

    Belyaev, B. A.; Khodenkov, S. A.; Balva, Ya F.; Aplesnin, S. S.; Bandurina, O. N.

    2016-11-01

    Filters of the 6th order, based on 2D electromagnetic crystals were developed. Application in structures of resonators with convolved and earthed on its base with strip conductors enables the implementation of filters having high frequency-selective properties and demanded in the aerospace equipment.

  9. Optical Characterization of Properties of Split Ring Resonators

    NASA Astrophysics Data System (ADS)

    de Alba, Roberto; Wang, Kai; Kim, Kyongwan; Bassett, Robert; Trendafilova, Cynthia; Burzo, Andrea; Lyuksyutov, Igor; Sokolov, Alexei

    2008-10-01

    Negative index materials (NIMs) are artificially made structures with unit cells smaller than the wavelength of incident light. Conceptually, these materials have the potential to revolutionize current technologies -- from allowing us to resolve structures smaller than the wavelength of light, to paving the path towards `invisibility cloaks'. In the past, these structures have been demonstrated to exhibit a negative index of refraction for microwave frequencies. Today, the goal is to develop structures with these properties in the visible wavelength range, and state-of-the-art research has already led to NIMs with resonances near infrared wavelengths. In this work we investigate the influence of different parameters, including size, material, and substrate on the resonant properties of the split ring resonator structures (SRR). In particular, the use of semiconductor substrates could lead to control of the resonant frequencies due to changes in carrier concentration.

  10. An antenna-coupled split-ring resonator for biosensing

    NASA Astrophysics Data System (ADS)

    Torun, H.; Cagri Top, F.; Dundar, G.; Yalcinkaya, A. D.

    2014-09-01

    An antenna-coupled split-ring resonator-based microwave sensor is introduced for biosensing applications. The sensor comprises a metallic ring with a slit and integrated monopole antennas on top of a dielectric substrate. The backside of the substrate is attached to a metallic plate. Integrated antennas are used to excite the device and measure its electromagnetic characteristics. The resonant frequency of the device is measured as 2.12 GHz. The characteristics of the device with dielectric loading at different locations across its surface are obtained experimentally. The results indicate that dielectric loading reduces the resonant frequency of the device, which is in good agreement with simulations. The shift in resonant frequency is employed as the sensor output for biomolecular experiments. The device is demonstrated as a resonant biomolecular sensor where the interactions between heparin and fibroblast growth factor 2 are probed. The sensitivity of the device is obtained as 3.7 MHz/(μg/ml) with respect to changes in concentration of heparin.

  11. Gradient index plasmonic ring resonator with high extinction ratio

    NASA Astrophysics Data System (ADS)

    Zhou, Zidong; He, Pengbin; Xu, Jinyou; Zhuang, Xiujuan; Li, Yunyun; Pan, Anlian

    2014-02-01

    We propose and investigate a compact gradient index plasmonic ring resonator (Grin PRR) with strong light confinement and extinction ratio based on finite element method (FEM). Theoretical simulation reveals that the change of index gradient influences the resonant frequency, Q factor and the mode volume. Significantly, it is demonstrated that the extinction ratio of Grin PRR can be optimized by varying the index gradient for any radius. Index gradient can enhance extinction ratio at settled size, so this structure has both high extinction ratio and smaller size footprint. It could be very promising for the high-density optical integration.

  12. Influence of the Biasing Scheme on the Performance of Au/SrTiO3/LaAlO3 Thin Film Conductor/Ferroelectric Tunable Ring Resonators

    NASA Technical Reports Server (NTRS)

    VanKeuls, F. W.; Romanofsky, R. R.; Bohman, D. Y.; Miranda, F. A.

    1998-01-01

    The performance of gold/SrTio3 /LaAlO3 conductor/ferroelectric/dielectric side-coupled, tunable ring resonators at K-band frequencies is presented. The tunability of these rings arises from the sensitivity of the relative dielectric constant (Er) of SrTiO 3 to changes in temperature and dc electric fields (E). We observed that the change in F-, which takes place by biasing the ring up to 450 V alters the effective dielectric constant (e-eff) of the circuit resulting in a 3k resonant frequency shift of nearly 12 % at 77 K. By applying a separate dc bias between the microstrip line and the ring, one can optimize their coupling to obtain bandstop resonators with unloaded quality factors (Q(sub o)) as high as 12,000. The 31 resonance was tuned from 15.75 to 17.41 GHz while keeping Q. above 768 over this range. The relevance of these results for practical microwave components will be discussed.

  13. Integrated optics ring-resonator sensors for protein detection.

    PubMed

    Ksendzov, A; Lin, Y

    2005-12-15

    Using an integrated optics ring-resonator biosensor, we have demonstrated the detection of protein in low concentrations. We detected 0.3 nM of avidin in a buffered saline solution; the calculated detection limit is 0.1 nM (6.8 ng/ml) for avidin, which compares favorably with those of other optical protein detection techniques. Further improvement is possible. Our ring resonator utilizes Si(x)N(y)/SiO2 waveguides, which, owing to evanescent field interaction, change the effective refractive index when target molecules are immobilized on their surfaces. The selectivity of the sensor depends on the biotin surface coating, which causes the specific binding and immobilization of avidin.

  14. High-Power Ka-Band Window and Resonant Ring

    SciTech Connect

    Jay L. Hirshfield

    2006-11-29

    A stand-alone 200 MW rf test station is needed for carrying out development of accelerator structures and components for a future high-gradient multi-TeV collider, such as CLIC. A high-power rf window is needed to isolate the test station from a structure element under test. This project aimed to develop such a window for use at a frequency in the range 30-35 GHz, and to also develop a high-power resonant ring for testing the window. During Phase I, successful conceptual designs were completed for the window and the resonant ring, and cold tests of each were carried out that confirmed the designs.

  15. Integrated optics ring-resonator sensors for protein detection

    NASA Astrophysics Data System (ADS)

    Ksendzov, A.; Lin, Y.

    2005-12-01

    Using an integrated optics ring-resonator biosensor, we have demonstrated the detection of protein in low concentrations. We detected 0.3 nM of avidin in a buffered saline solution; the calculated detection limit is 0.1 nM (6.8ng/ml) for avidin, which compares favorably with those of other optical protein detection techniques. Further improvement is possible. Our ring resonator utilizes SixNy/SiO2 waveguides, which, owing to evanescent field interaction, change the effective refractive index when target molecules are immobilized on their surfaces. The selectivity of the sensor depends on the biotin surface coating, which causes the specific binding and immobilization of avidin.

  16. Efficiently heralded silicon ring resonator photon-pair source

    NASA Astrophysics Data System (ADS)

    Steidle, Jeffrey A.; Fanto, Michael L.; Tison, Christopher C.; Wang, Zihao; Alsing, Paul M.; Preble, Stefan F.

    2016-05-01

    Presented here are results on a silicon ring resonator photon pair source with a high heralding efficiency. Previous ring resonator sources suffered from an effective 50% loss because, in order to generate the photons, the pump must be able to couple into the resonator which is an effective loss channel. However, in practice the optical loss of the pump can be traded off for a dramatic increase in heralding efficiency. This research found theoretically that the heralding efficiency should increase by a factor of ~ 3:75 with a factor of 10 increase in the required pump power. This was demonstrated experimentally by varying the separation (gap) between the input waveguide and the ring while maintaining a constant drop port gap. The ring (R = 18:5μm, W = 500nm, and H = 220nm) was pumped by a tunable laser (λ ≍ 1550nm). The non-degenerate photons, produced via spontaneous four wave mixing, exited the ring and were coupled to fiber upon which they were filtered symmetrically about the pump. Coincidence counts were collected for all possible photon path combinations (through and drop port) and the ratio of the drop port coincidences to the sum of the drop port and cross term coincidences (one photon from the drop port and one from the through port) was calculated. With a 350nm pump waveguide gap (2:33 times larger than the drop port gap) we confirmed our theoretical predictions, with an observed improvement in heralding efficiency by a factor of ~ 2:61 (96:7% of correlated photons coupled out of the drop port). These results will enable increased photon flux integrated photon sources which can be utilized for high performance quantum computing and communication systems.

  17. Ultra-Small Dualband Dualmode Microstrip Antenna Based on Novel Hybrid Resonator

    NASA Astrophysics Data System (ADS)

    Zhu, Ji-Xu; Bai, Peng; Zheng, Hao-Zhong

    2016-11-01

    A novel hybrid resonator consists of right handed patch+composite right and left handed transmission line (RH+CRLH) is proposed for the first time aiming at both compactness and frequency manipulation. A demonstration with theoretical dispersion relations and EM simulation is provided for the correctness and efficiency. According to the new method, an ultra-small and dualband antenna operating around 2.4 GHz (n=0, Bluetooth band) and 3.5 GHz (n=+1, Wimax band) is designed, fabricated and measured, whose occupied area is only of 0.158 λ_0. Numerical and experimental results indicate that the antenna exhibits a good impendence match, low cross-polarization and comparable radiation gains in both bands. Excellent performances of the antennas based on hybrid resonators predict promising applications in multifunction wireless communication systems.

  18. SERS-based detection in an optofluidic ring resonator platform.

    PubMed

    White, Ian M; Gohring, John; Fan, Xudong

    2007-12-10

    The development of surface enhanced Raman scattering (SERS) detection has made Raman spectroscopy relevant for highly sensitive labon- a-chip bio/chemical sensors. Despite the tremendous benefit in specificity that a Raman-based sensor can deliver, development of a lab-on-a- chip SERS tool has been limited thus far. In this work, we utilize an optofluidic ring resonator (OFRR) platform to develop a SERS-based detection tool with integrated microfluidics. The liquid core optical ring resonator (LCORR) serves both as the microfluidic sample delivery mechanism and as a ring resonator, exciting the metal nanoclusters and target analytes as they pass through the channel. Using this OFRR approach and R6G as the analyte, we have achieved a measured detection limit of 400 pM. The measured Raman signal in this case is likely generated by only a few hundred R6G molecules, which foreshadows the development of a SERS-based lab-on-a-chip bio/chemical sensor capable of detecting a low number of target analyte molecules.

  19. All-optical nonlinear plasmonic ring resonator switches

    NASA Astrophysics Data System (ADS)

    Nozhat, N.; Granpayeh, N.

    2014-11-01

    In this paper, all-optical nonlinear plasmonic ring resonator (PRR) switches containing 90o sharp and smooth bends have been proposed and numerically analyzed by the finite-difference time-domain method. Kerr nonlinear self-phase modulation (SPM) and cross-phase modulation (XPM) effects on the switching performance of the device have been studied. By applying a high-power lightwave, the signal can switch from one port to the other port due to the ON/OFF resonant states of the ring. We have shown that by utilizing the XPM effect, the output power ratio is improved by a factor of 2.5 and the required switching power is 31% of that of the case with only the SPM effect. Moreover, by utilizing sharp bend square-shaped ring resonators, the switching power is 10.4% lower than that of the smooth ones. The nonlinear PRR switches are suitable for application in photonic-integrated circuits as all-optical switches because of their nanoscale size and low required switching power.

  20. Temperature Dependence of the Surface Resistance of a Bi-Sr-Ca-Cu-O Whisker Measured by the Probe-Coupled Microstrip Resonator Method

    NASA Astrophysics Data System (ADS)

    Okai, Daisuke; Ohshima, Shigetoshi; Kishida, Satoru; Hatano, Takeshi

    2001-07-01

    The temperature dependence of the surface resistance of Bi-Sr-Ca-Cu-O whiskers measured by the probe-coupled microstrip resonator method was examined. Two kinds of whiskers were measured: plate-like and wire-like. The surface resistances of the plate-like and wire-like whiskers were 0.65 mΩ and 1.6 mΩ at 53 K and 6.9 GHz, respectively. These values were approximately 4 ˜ 10 times larger than that of a high-quality Bi2Sr2CaCu2Ox (Bi-2212) single crystal.

  1. The microstrip SQUID amplifier

    NASA Astrophysics Data System (ADS)

    Therrien, Roy

    A Superconducting Quantum Interference Devices (SQUIDS) can operate at frequencies up to several GHz and can be cooled to less than 100 mK. Such characteristics make the SQUID---a flux-to-voltage transducer---an excellent candidate for use as a low-noise rf amplifier. Coupling of input signals of frequencies larger than 200 MHz, however, has been limited by the parasitic capacitance between the input coil and SQUID body. We present experimental observations of a do SQUID-based rf amplifier which circumvents this problem by incorporating the input coil as a microstrip resonator. The microstrip input configuration uses the capacitance and inductance of the input coil to form a resonant cavity capable of operating up to several GHz. The input signal is applied between the SQUID body and one end of the input coil, while the other end of the coil is left open. We present data from microstrip SQUID amplifiers with gains of up to 22 dB at 900 MHz. In order to understand the gain and input impedance of the microstrip SQUID in greater detail, we made and studied a 1:190 scale analog patterned on a double-sided printed circuit board consisting of copper deposited on a kapton sheet. The measured input impedance of the analog SQUID is successfully modeled by describing the microstrip input as a low-loss transmission line. When operated with the slit in the copper washer ground plane shorted, the input coil behaves exactly like a linear resonator with the resonant frequency given by f = 1/2ℓ(L 0C0)1/2, where L0 and C0 are the inductance and capacitance per unit length and ℓ is the coil length. With the slit in the washer left open, the inductance of the input coil is significantly altered in a manner partially consistent with the Ketchen-Jaycox model in which the reflected inductance of the input coil is Li = n2L, where L is the inductance of the washer loop and n is the number of turns in the coil. We present input impedance measurements on microstrip SQUIDs cooled to 4

  2. F Ring Core Stability: Corotation Resonance Plus Antiresonance

    NASA Astrophysics Data System (ADS)

    Cuzzi, Jeffrey N.; Marouf, Essam; French, Richard; Jacobson, Robert

    2014-11-01

    The decades-or-longer stability of the narrow F Ring core in a sea of orbital chaos appears to be due to an unusual combination of traditional corotation resonance and a novel kind of “antiresonance”. At a series of specific locations in the F Ring region, apse precession between synodic encounters with Prometheus allows semimajor axis perturbations to promptly cancel before significant orbital period changes can occur (Cuzzi et al. 2014, Icarus 232, 157-175). This cancellation fails for particles that encounter Prometheus when it is near its apoapse, especially during periods of antialignment of its apse with that of the F Ring. At these times, the strength of the semimajor axis perturbation is large (tens of km) and highly nonsinusoidal in encounter longitude, making it impossible to cancel promptly on a subsequent encounter and leading to chaotic orbital diffusion. Only particles that consistently encounter Prometheus away from its apoapse can use antiresonance to maintain stable orbits, implying that the true mean motion nF of the stable core must be defined by a corotational resonance of the form nF = nP-κP/m, where (nP, κP) are Prometheus’ mean motion and epicycle frequency. To test this hypothesis we used the fact that Cassini RSS occultations only sporadically detect a “massive” F Ring core, composed of several-cm-and-larger particles. We regressed the inertial longitudes of 24 Cassini RSS (and VGR) detections and 43 nondetections to a common epoch, using a comb of candidate nP, and then folded them modulo the anticipated m-number of the corotational resonance (Prometheus m=110 outer CER), to see if clustering appears. We find the “true F Ring core” is actually arranged in a series of short longitudinal arcs separated by nearly empty longitudes, orbiting at a well determined semimajor axis of 140222.4km (from 2005-2012 at least). Small particles seen by imaging and stellar occultations spread quickly in azimuth and obscure this clumpy

  3. F Ring Core Stability: Corotation Resonance Plus Antiresonance

    NASA Technical Reports Server (NTRS)

    Cuzzi, Jeffrey N.; Marouf, Essam; French, Richard; Jacobson, Robert

    2014-01-01

    The decades-or-longer stability of the narrow F Ring core in a sea of orbital chaos appears to be due to an unusual combination of traditional corotation resonance and a novel kind of "antiresonance". At a series of specific locations in the F Ring region, apse precession between synodic encounters with Prometheus allows semimajor axis perturbations to promptly cancel before significant orbital period changes can occur. This cancellation fails for particles that encounter Prometheus when it is near its apoapse, especially during periods of antialignment of its apse with that of the F Ring. At these times, the strength of the semimajor axis perturbation is large (tens of km) and highly nonsinusoidal in encounter longitude, making it impossible to cancel promptly on a subsequent encounter and leading to chaotic orbital diffusion. Only particles that consistently encounter Prometheus away from its apoapse can use antiresonance to maintain stable orbits, implying that the true mean motion nF of the stable core must be defined by a corotational resonance of the form nF = nP(-kappa)P/m, where (nP, kappaP) are Prometheus' mean motion and epicycle frequency. To test this hypothesis we used the fact that Cassini RSS occultations only sporadically detect a "massive" F Ring core, composed of several-cm-and-larger particles. We regressed the inertial longitudes of 24 Cassini RSS (and VGR) detections and 43 nondetections to a common epoch, using a comb of candidate nP, and then folded them modulo the anticipated m-number of the corotational resonance (Prometheus m = 110 outer CER), to see if clustering appears. We find the "true F Ring core" is actually arranged in a series of short longitudinal arcs separated by nearly empty longitudes, orbiting at a well determined semimajor axis of 140222.4 km (from 2005-2012 at least). Small particles seen by imaging and stellar occultations spread quickly in azimuth and obscure this clumpy structure. Small chaotic variations in the mean

  4. A study of the main resonances outside the geostationary ring

    NASA Astrophysics Data System (ADS)

    Celletti, Alessandra; Galeş, Cătălin

    2015-08-01

    We investigate the dynamics of satellites and space debris in external resonances, namely in the region outside the geostationary ring. Precisely, we focus on the 1:2, 1:3, 2:3 resonances, which are located at about 66 931.4 km, 87 705.0 km, 55 250.7 km, respectively. Some of these resonances have been already exploited in space missions, like XMM-Newton and Integral. Our study is mainly based on a Hamiltonian approach, which allows us to get fast and reliable information on the dynamics in the resonant regions. Significative results are obtained even by considering just the effect of the geopotential in the Hamiltonian formulation. For objects (typically space debris) with high area-to-mass ratio the Hamiltonian includes also the effect of the solar radiation pressure. In addition, we perform a comparison with the numerical integration in Cartesian variables, including the geopotential, the gravitational attraction of Sun and Moon, and the solar radiation pressure. We implement some simple mathematical tools that allows us to get information on the terms which are dominant in the Fourier series expansion of the Hamiltonian around a given resonance, on the amplitude of the resonant islands and on the location of the equilibrium points. We also compute the Fast Lyapunov Indicators, which provide a cartography of the resonant regions, yielding the main dynamical features associated to the external resonances. We apply these techniques to analyze the 1:2, 1:3, 2:3 resonances; we consider also the case of objects with large area-to-mass ratio and we provide an application to the case studies given by XMM-Newton and Integral.

  5. Crossed ring anchored disk resonator for self-alignment of the anchor

    PubMed Central

    Baghelani, Masoud; Ghavifekr, Habib Badri; Ebrahimi, Afshin

    2013-01-01

    Misalignment is a problematic challenge in RF MEMS resonators. It causes asymmetry in the ultra symmetric radial contour mode disk resonators and degrades their performance by increasing the insertion loss and decreasing their quality factors (Q). Self-alignment method seems to be a good solution for misalignment problem, but it cannot be directly applied on high performance ring shape anchored resonators. This paper discusses misalignment effects for the ring shape anchored resonators and proposes a method for reconfiguring its anchor to be compatible with self-alignment process. Simulation results validate that the crossed ring anchor structure has the same resonance characteristics with the complete ring shape anchored resonator. PMID:25685477

  6. Numerical study of opto-fluidic ring resonators for biosensor applications.

    PubMed

    Cho, Han Keun; Han, Jinwoo

    2012-10-22

    The opto-fluidic ring resonator (OFRR) biosensor is numerically characterized in whispering gallery mode (WGM). The ring resonator includes a ring, a waveguide and a gap separating the ring and the waveguide. Dependence of the resonance characteristics on the resonator size parameters such as the ring diameter, the ring thickness, the waveguide width, and the gap width between the ring and the waveguide are investigated. For this purpose, we use the finite element method with COMSOL Multiphysics software to solve the Maxwell's equations. The resonance frequencies, the free spectral ranges (FSR), the full width at half-maximum (FWHM), finesse (F), and quality factor of the resonances (Q) are examined. The resonant frequencies are dominantly affected by the resonator diameter while the gap width, the ring thickness and the waveguide width have negligible effects on the resonant frequencies. FWHM, the quality factor Q and the finesse F are most strongly affected by the gap width and moderately influenced by the ring diameter, the waveguide width and the ring thickness. In addition, our simulation demonstrates that there is an optimum range of the waveguide width for a given ring resonator and this value is between ~2.25 μm and ~2.75 μm in our case.

  7. Transmission of asymmetric coupling double-ring resonator

    NASA Astrophysics Data System (ADS)

    Zhao, C. Y.; Tan, W. H.

    2015-02-01

    Based on the asymmetry between waveguide and double ring, the transmission and phase characteristics of coupled double-ring resonators are analyzed systemically. It is shown that the initial detuning determines the shape of transmission spectrum. The transmission spectrum of all-optical analog to electromagnetic inducted transparency (EIT) is controlled by tuning the asymmetric coupled parameter and loss. With the increasing of asymmetric coupled parameter, the transmission spectrum changes from EIT-like profile to Lorenz profile. The EIT-like transmission spectrum results from the interference between two Lorenz profiles. With the increasing of the loss, the transmission spectrum full frequency width at half-maximum broadens and its peak declines. The detuning and loss also make significant influences on the phase profile.

  8. A 58 sq m Passive Resonant Ring Laser Gyroscope

    NASA Astrophysics Data System (ADS)

    Shaw, G. L.; Simmons, B. J.

    1984-01-01

    A 7.62 x 7.62 m Passive Ring Resonator Laser Gyro (PRRLG) is analyzed. Each element of the PRRLG is consistent with the requirements for geophysical applications, which would include precision measurements of earth rotation and polar wobble. The shot noise limit was calculated to be about 3 x 10 to the -8th ERU (tau = 1 sec), and, with a predicted transition Fourier frequency between white noise and 1/f noise at about 200 microHz, a resolution on the order of about 4 x 10 to the -10th ERU is feasible.

  9. Chariklo's ring system 3. Exploration of possible Chariklo spin/ring orbit resonances

    NASA Astrophysics Data System (ADS)

    Sicardy, Bruno; El Moutamid, Maryame; Leiva, Rodrigo; Berard, Diane; Renner, Stéfan

    2016-10-01

    Two dense and narrow rings orbit the Centaur object Chariklo at respective radii of 391±3 and 405±3 km (Braga-Ribas et al., Nature 508, 72, 2014).With a rotation period of PC = 7.004 ± 0.036 h (Fornasier et al. A.&A. 568, L11, 2014), Chariklo may adopt either a MacLaurin spheroid or a Jacobi ellipsoid shape, depending on density (and assuming hydrostatic equilibrium). Moreover, being a small icy body, Chariklo is prone to topographic features at several-kilometer scales.Meanwhile, scarce information on Chariklo's size and shape is presently available from occultation works, as only five chords have been obtained during three occultations that have been observed in 2013 and 2014. Those data are consistent with a MacLaurin shape with axes a, b, c ~ 133x133x110 km and mass MC ~ (1-2)x1019 kg, or with a Jacobi shape with a, b, c ~ 167x133x124 km and MC ~ 0.6-0.7x1019 kg, see the companion paper by Leiva et al.Those values imply a corotation radius between 190 and 280 km, depending on the adopted value of MC. This is well inside the ring radii, ruling out the corotation resonance as the main driver for the ring orbital dynamics.The ring orbital period could lie between Pr ~12 and 22 h, depending on MC, thus allowing possible resonances with Chariklo's spin rate ΩC. Two models will be explored. One model assumes a MacLaurin shape with a topographic feature of mass m that acts as perturbing satellites with orbital radius and period a and PC, respectively. This creates 1st order Linblad-type resonances of the kind Pr/PC = m+1/m (m integer) whose possible effects on the ring structure will be evaluated.The other model assumes a Jacobi shape that creates a perturbing potential GMc/r3 [(A+B-2C)2 + (3/2)(A-B).cos(2θ)] with θ= λ-ΩC.t in Chariklo's equatorial plane, where A, B, C are the moments of inertia around a, b, c, respectively, and λ is the mean longitude. This creates qth order Linblad-type resonances of the kind Pr/PC = q+2/q (q integer) that will also be

  10. Coupling thermal atomic vapor to an integrated ring resonator

    NASA Astrophysics Data System (ADS)

    Ritter, R.; Gruhler, N.; Pernice, W. H. P.; Kübler, H.; Pfau, T.; Löw, R.

    2016-10-01

    Strongly interacting atom-cavity systems within a network with many nodes constitute a possible realization for a quantum internet which allows for quantum communication and computation on the same platform. To implement such large-scale quantum networks, nanophotonic resonators are promising candidates because they can be scalably fabricated and interconnected with waveguides and optical fibers. By integrating arrays of ring resonators into a vapor cell we show that thermal rubidium atoms above room temperature can be coupled to photonic cavities as building blocks for chip-scale hybrid circuits. Although strong coupling is not yet achieved in this first realization, our approach provides a key step towards miniaturization and scalability of atom-cavity systems.

  11. Plasmon coupling in vertical split-ring resonator metamolecules.

    PubMed

    Wu, Pin Chieh; Hsu, Wei-Lun; Chen, Wei Ting; Huang, Yao-Wei; Liao, Chun Yen; Liu, Ai Qun; Zheludev, Nikolay I; Sun, Greg; Tsai, Din Ping

    2015-06-05

    The past decade has seen a number of interesting designs proposed and implemented to generate artificial magnetism at optical frequencies using plasmonic metamaterials, but owing to the planar configurations of typically fabricated metamolecules that make up the metamaterials, the magnetic response is mainly driven by the electric field of the incident electromagnetic wave. We recently fabricated vertical split-ring resonators (VSRRs) which behave as magnetic metamolecules sensitive to both incident electric and magnetic fields with stronger induced magnetic dipole moment upon excitation in comparison to planar SRRs. The fabrication technique enabled us to study the plasmon coupling between VSRRs that stand up side by side where the coupling strength can be precisely controlled by varying the gap in between. The resulting wide tuning range of these resonance modes offers the possibility of developing frequency selective functional devices such as sensors and filters based on plasmon coupling with high sensitivity.

  12. Microwave microstrip resonator measurements of Y1Ba2Cu3O(7-x) and Bi2Sr2Ca1Cu2O(8-y) thin films

    NASA Technical Reports Server (NTRS)

    Lichtenberg, Christopher L.; Wosik, Jaroslaw; Davis, Matthew; Wolfe, J. C.

    1989-01-01

    Radio frequency (RF) surface resistance measurement experiments on high T(sub c) thin films were performed. The method uses a microstrip resonator comprising a top gold conductor strip, an alumina dielectric layer, and a separate superconductivity ground plane. The surface resistance of the superconducting ground plane can be determined, with reference to a gold calibration standard, from the measured quality factor of the half-wave resonator. Initial results near 7 GHz over the temperature range from 25 to 300 K are presented for YBa2Cu3O(7-x) and Bi2Sr2CaCu2O(8-y) thin film samples deposited by an electron beam flash evaporation process. The RF surface resistance at 25 K for both materials in these samples was found to be near 25 milliohms.

  13. Resonance control of mid-infrared metamaterials using arrays of split-ring resonator pairs.

    PubMed

    Yue, Weisheng; Wang, Zhihong; Whittaker, John; Schedin, Fredrik; Wu, Zhipeng; Han, Jiaguang

    2016-02-05

    We present our design, fabrication and characterization of resonance-controllable metamaterials operating at mid-infrared wavelengths. The metamaterials are composed of pairs of back-to-back or face-to-face U-shape split-ring resonators (SRRs). Transmission spectra of the metamaterials are measured using Fourier-transform infrared spectroscopy. The results show that the transmission resonance is dependent on the distance between the two SRRs in each SRR pair. The dips in the transmission spectrum shift to shorter wavelengths with increasing distance between the two SRRs for both the back-to-back and face-to-face SRR pairs. The position of the resonance dips in the spectrum can hence be controlled by the relative position of the SRRs. This mechanism of resonance control offers a promising way of developing metamaterials with tunability for optical filters and bio/chemical sensing devices in integrated nano-optics.

  14. 3D simulation of silicon micro-ring resonator with Comsol

    NASA Astrophysics Data System (ADS)

    Degtyarev, S. A.; Podlipnov, V. V.; Verma, Payal; Khonina, S. N.

    2016-12-01

    In this paper we provide 3d full-vector static electromagnetic simulation of silicon micro-ring resonator operating. We show that geometrical and scalar approaches are not sufficiently accurate for calculating resonator parameters. Quite strong dependence of ring resonator radius on waveguide width is revealed.

  15. A compact symmetric microstrip filter based on a rectangular meandered-line stepped impedance resonator with a triple-band bandstop response.

    PubMed

    Dhakal, Rajendra; Kim, Nam-Young

    2013-01-01

    This paper presents a symmetric-type microstrip triple-band bandstop filter incorporating a tri-section meandered-line stepped impedance resonator (SIR). The length of each section of the meandered line is 0.16, 0.15, and 0.83 times the guided wavelength (λ g ), so that the filter features three stop bands at 2.59 GHz, 6.88 GHz, and 10.67 GHz, respectively. Two symmetric SIRs are employed with a microstrip transmission line to obtain wide bandwidths of 1.12, 1.34, and 0.89 GHz at the corresponding stop bands. Furthermore, an equivalent circuit model of the proposed filter is developed, and the model matches the electromagnetic simulations well. The return losses of the fabricated filter are measured to be -29.90 dB, -28.29 dB, and -26.66 dB while the insertion losses are 0.40 dB, 0.90 dB, and 1.10 dB at the respective stop bands. A drastic reduction in the size of the filter was achieved by using a simplified architecture based on a meandered-line SIR.

  16. Ring-resonator-integrated tunable external cavity laser employing EAM and SOA.

    PubMed

    Yoon, Ki-Hong; Kwon, O-Kyun; Kim, Ki Soo; Choi, Byung-Seok; Oh, Su Hwan; Kim, Hyun Su; Sim, Jae-Sik; Kim, Chul Soo

    2011-12-05

    We propose and demonstrate a tunable external cavity laser (ECL) composed of a polymer Bragg reflector (PBR) and integrated gain chip with gain, a ring resonator, an electro-absorption modulator (EAM), and a semiconductor optical amplifier (SOA). The cavity of the laser is composed of the PBR, gain, and ring resonator. The ring resonator reflects the predetermined wavelengths into the gain region and transmits the output signal into integrated devices such as the EAM and SOA. The output wavelength of the tunable laser is discretely tuned in steps of about 0.8 nm through the thermal-optic effect of the PBR and predetermined mode spacing of the ring resonator.

  17. Hamiltonian optics formalism for microring resonator structures with varying ring resonances.

    PubMed

    Sun, Xiaolan; Yang, Zhenshan; Liu, Xiaohong; Li, Chao; Dong, Yanhua; Xie, Libin; Sipe, J E

    2011-04-11

    We develop a Hamiltonian optics formalism to quantitatively analyze a recently proposed scheme for increasing the delay-time-bandwidth product for microring resonator structures with varying ring resonances [Yang and Sipe, Opt. Lett. 32, 918 (2007)]. This theory is formally compact, simple and physically intuitive. We compare this formalism with the more rigorous transfer matrix method, and conclude that the Hamiltonian optics formalism correctly gives the average dispersion, which essentially determines the group delay as well as the dispersive distortion for pulses in the ps regime or longer.

  18. Microwave memristive behavior in split-ring resonator metamaterials

    NASA Astrophysics Data System (ADS)

    Wu, H. Y.; Shi, S. K.; Wang, C. H.; Jiang, X. J.; Yu, G.; Qin, G. Q.; Fu, H.; Zhou, J.

    2016-07-01

    Photonic memristors, which behave as memristors operating with electromagnetic fields, present an effective means to achieve all-optical networking, and can promote the development of optical communications and computer technology. In this paper, we report a microwave memristive phenomenon at room temperature in metamaterials consisting of negative temperature coefficient thermistor ceramic disk and split-ring resonator (SRR). Hysteretic transmission-incident field power loops, the area of which varies with the scan rate of power, (similar to the fingerprint of memristors) were observed in the metamaterials. These effects are attributed to the increasing conductivity of the ceramic disk with increasing temperature generated by the interaction between electromagnetic waves and metamaterials. This work offers new opportunities for the development of photonic memristors.

  19. Optofluidic ring resonator sensors for rapid DNT vapor detection.

    PubMed

    Sun, Yuze; Liu, Jing; Frye-Mason, Greg; Ja, Shiou-jyh; Thompson, Aaron K; Fan, Xudong

    2009-07-01

    We demonstrated rapid 2,4-dinitrotoluene (DNT) vapor detection at room temperature based on an optofluidic ring resonator (OFRR) sensor. With the unique on-column separation and detection features of OFRR vapor sensors, DNT can be identified from other interferences coexisting in the analyte sample mixture, which is especially useful in the detection of explosives from practical complicated vapor samples usually containing more volatile analytes. The DNT detection limit is approximately 200 pg, which corresponds to a solid phase microextraction (SPME) sampling time of only 1 second at room temperature from equilibrium headspace. A theoretical analysis was also performed to account for the experimental results. Our study shows that the OFRR vapor sensor is a promising platform for the development of a rapid, low-cost, and portable analytical device for explosive detection and monitoring.

  20. Tunable polarization beam splitter based on optofluidic ring resonator.

    PubMed

    Zhu, Song; Liu, Yang; Shi, Lei; Xu, Xinbiao; Yuan, Shixing; Liu, Ningyu; Zhang, Xinliang

    2016-07-25

    An efficient polarization beam splitter (PBS) based on an optofluidic ring resonator (OFRR) is proposed and experimentally demonstrated. The PBS relies on the large effective refractive index difference between transverse-electric (TE) and transverse-magnetic (TM) polarization states, since the silica-microcapillary-based OFRR possesses a slab-like geometry configuration in the cross section through which the circulating light travels. To the best of our knowledge, this is the first OFRR-based PBS. In our work, the maximum polarization splitting ratio of up to 30 dB is achieved. Besides, water and ethanol are pumped into the core of the silica microcapillary respectively, and the maximum wavelength tuning range of 7.02 nm is realized when ethanol flows through the core, verifing the tuning principle of the PBS effectively. With such a good performance and simple scheme, this OFRR-based PBS is promising for applications such as tunable optical filters, demultiplexers, and routers.

  1. Electron Spectroscopy In Heavy-Ion Storage Rings: Resonant and Non-Resonant Electron Transfer Processes

    SciTech Connect

    Hagmann, S.; Stoehlker, Th.; Trotsenko, S.; Kozhuharov, Ch.; Spillmann, U.; Bosch, F.; Liesen, D.; Winters, D.; Hillenbrand, P.-M.; Shabaev, V.; Tupitsyn, I.; Kozhedub, Y.; Rothard, H.; Reuschl, R.; Ullrich, J.; Moshammer, R.; Voitkiv, A.; Surzhykov, A.; Fischer, D.; Doerner, R.

    2011-06-01

    Whereas our understanding of total cross sections for ionization and capture processes in ion-atom collisions is widely viewed as having arrived at a state of adequate maturity, the same cannot be said at all about the dynamics of collisions, multi-electron processes or the electron continua (in target and projectile) which are at the origin of total cross sections. We depict how these processes can be studied favourably in storage ring environments. We present examples of resonant and non-resonant electron transfer processes, radiative and non-radiative. This is elucidated via the relation of the electron nucleus bremsstrahlung at the high energy tip of the bremsstrahlung spectrum to the radiative electron capture cusp (RECC) and a new approach to determining molecular orbital binding energies in superheavy quasi-molecules in resonant KK charge transfer.

  2. Versatile optofluidic ring resonator lasers based on microdroplets.

    PubMed

    Lee, Wonsuk; Luo, Yunhan; Zhu, Qiran; Fan, Xudong

    2011-09-26

    We develop a novel nL-sized microdroplet laser based on the capillary optofluidic ring resonator (OFRR). The microdroplet is generated in a microfluidic channel using two immiscible fluids and is subsequently delivered to the capillary OFRR downstream. Despite the presence of the high refractive index (RI) carrier fluid, the lasing emission can still be achieved for the droplet formed by low RI solution. The lasing threshold of 1.54 µJ/mm(2) is achieved, >6 times lower than the state-of-the-art, thanks to the high Q-factor of the OFRR. Furthermore, the lasing emission can be conveniently coupled into an optical fiber. Finally, tuning of the lasing wavelength is achieved via highly efficient fluorescence resonance energy transfer processes by merging two different dye droplets in the microfluidic channel. Versatility combined with improved lasing characteristics makes our OFRR droplet laser an attractive platform for high performance optofluidic lasers and bio/chemical sensing with small sample volumes.

  3. Multiple magnetic mode-based Fano resonance in split-ring resonator/disk nanocavities.

    PubMed

    Zhang, Qing; Wen, Xinglin; Li, Guangyuan; Ruan, Qifeng; Wang, Jianfang; Xiong, Qihua

    2013-12-23

    Plasmonic Fano resonance, enabled by the weak interaction between a bright super-radiant and a subradiant resonance mode, not only is fundamentally interesting, but also exhibits potential applications ranging from extraordinary optical transmission to biosensing. Here, we demonstrate strong Fano resonances in split-ring resonators/disk (SRR/D) nanocavities. The high-order magnetic modes are observed in SRRs by polarization-resolved transmission spectroscopy. When a disk is centered within the SRRs, multiple high-order magnetic modes are coupled to a broad electric dipole mode of SRR/D, leading to significant Fano resonance spectral features in near-IR regime. The strength and line shape of the Fano resonances are tuned through varying the SRR split-angle and interparticle distance between SRR and disk. Finite-difference-time-domain (FDTD) simulations are conducted to understand the coupling mechanism, and the results show good agreement with experimental data. Furthermore, the coupled structure gives a sensitivity of ∼282 nm/RIU with a figure of merit ∼4.

  4. Finite Difference Time Domain (FDTD) Analysis of a Leaky Traveling Wave Microstrip Antenna

    DTIC Science & Technology

    2007-11-02

    aviobj = avifile([name,’.avi’],’ fps ’,12,’quality’,100); end; %*********************************************************************** % FREQUENCY...Joachim and Rolf H. Jansen . “Spectral Domain Investigation of Surface Wave Excitation and Radiation by Microstrip Lines and Microstrip Disk Resonators

  5. Low-power microelectromechanically tunable silicon photonic ring resonator add-drop filter.

    PubMed

    Errando-Herranz, Carlos; Niklaus, Frank; Stemme, Göran; Gylfason, Kristinn B

    2015-08-01

    We experimentally demonstrate a microelectromechanically (MEMS) tunable photonic ring resonator add-drop filter, fabricated in a simple silicon-on-insulator (SOI) based process. The device uses electrostatic parallel plate actuation to perturb the evanescent field of a silicon waveguide, and achieves a 530 pm resonance wavelength tuning, i.e., more than a fourfold improvement compared to previous MEMS tunable ring resonator add-drop filters. Moreover, our device has a static power consumption below 100 nW, and a tuning rate of -62  pm/V, i.e., the highest reported rate for electrostatic tuning of ring resonator add-drop filters.

  6. Reducing support loss in micromechanical ring resonators using phononic band-gap structures

    NASA Astrophysics Data System (ADS)

    Hsu, Feng-Chia; Hsu, Jin-Chen; Huang, Tsun-Che; Wang, Chin-Hung; Chang, Pin

    2011-09-01

    In micromechanical resonators, energy loss via supports into the substrates may lead to a low quality factor. To eliminate the support loss, in this paper a phononic band-gap structure is employed. We demonstrate a design of phononic-crystal (PC) strips used to support extensional wine-glass mode ring resonators to increase the quality factor. The PC strips are introduced to stop elastic-wave propagation by the band-gap and deaf-band effects. Analyses of resonant characteristics of the ring resonators and the dispersion relations, eigenmodes, and transmission properties of the PC strips are presented. With the proposed resonator architecture, the finite-element simulations show that the leaky power is effectively reduced and the stored energy inside the resonators is enhanced simultaneously as the operating frequencies of the resonators are within the band gap or deaf bands. Realization of a high quality factor micromechanical ring resonator with minimized support loss is expected.

  7. Photon antibunching and bunching in a ring-resonator waveguide quantum electrodynamics system.

    PubMed

    Chen, Zihao; Zhou, Yao; Shen, Jung-Tsung

    2016-07-15

    We numerically investigate the photonic state generation and its nonclassical correlations in a ring-resonator waveguide quantum electrodynamics system. Specifically, we discuss photon antibunching and bunching in various scenarios, including the imperfect resonator with backscattering and dissipations. Our numerical results indicate that an imperfect ring resonator with backscattering can enhance the quality of antibunching. In addition, we also identify the quantum photonic halo phenomenon in the photon scattering dynamics and the shoulder effect in the second-order correlation function.

  8. Multidimensional Purcell effect in an ytterbium-doped ring resonator

    NASA Astrophysics Data System (ADS)

    Ding, Dapeng; Pereira, Lino M. C.; Bauters, Jared F.; Heck, Martijn J. R.; Welker, Gesa; Vantomme, André; Bowers, John E.; de Dood, Michiel J. A.; Bouwmeester, Dirk

    2016-06-01

    Rare-earth ions in solids are of particular interest for quantum information storage and processing because of the long coherence times of the 4f states. In the past few years, substantial progress has been made by using ensembles of ions and single ions. However, the weak optical transitions within the 4f manifold pose a great challenge to the optical interaction with a single rare-earth ion on a single-photon level. Here, we demonstrate a ninefold enhanced ion-light interaction (Purcell effect) in an integrated-optics-based, fibre-coupled silicon nitride (Si3N4) ring resonator with implanted ytterbium ions (Yb3+). We unveil the one-, two- and three-dimensional contributions to the Purcell factor as well as the temperature-dependent decoherence and depolarization of the ions. The results indicate that this cavity quantum electrodynamics (QED) system has the potential of interfacing single rare-earth ions with single photons on a chip.

  9. A band-pass plasmonic filter with dual-square ring resonator

    NASA Astrophysics Data System (ADS)

    Duan, Gaoyan; Lang, Peilin; Wang, Lulu; Yu, Li; Xiao, Jinghua

    2014-09-01

    In this paper, we show the simulation of a plasmonic band-pass filter which consists of two surface plasmon polaritons (SPPs) waveguides and a resonator in metal-insulator-metal (MIM) structure. The resonator is formed by two square rings and a patch between them. The patch is a tiny rectangle cavity in order to transfer the SPPs from one ring to the other. The finite element method (FEM) method is employed in simulation. The results show that the dual-ring resonator performs better than a single ring does. The 3 dB bandwidth near the peak wavelength λ = 1054 nm is merely 31.7 nm. The resonant wavelength can be shifted by changing the side length of the square ring. This narrow band-pass filter is easy to fabricate and has potential applications in future integrated optical circuits.

  10. Sequentially evaporated thin film YBa2Cu3O(7-x) superconducting microwave ring resonator

    NASA Technical Reports Server (NTRS)

    Rohrer, Norman J.; To, Hing Y.; Valco, George J.; Bhasin, Kul B.; Chorey, Chris; Warner, Joseph D.

    1990-01-01

    There is great interest in the application of thin film high temperature superconductors in high frequency electronic circuits. A ring resonator provides a good test vehicle for assessing the microwave losses in the superconductor and for comparing films made by different techniques. Ring resonators made of YBa2Cu3O(7-x) have been investigated on LaAlO3 substrates. The superconducting thin films were deposited by sequential electron beam evaporation of Cu, Y, and BaF2 with a post anneal. Patterning of the superconducting film was done using negative photolithography. A ring resonator was also fabricated from a thin gold film as a control. Both resonators had a gold ground plane on the backside of the substrate. The ring resonators' reflection coefficients were measured as a function of frequency from 33 to 37 GHz at temperatures ranging from 20 K to 68 K. The resonator exhibited two resonances which were at 34.5 and 35.7 GHz at 68 K. The resonant frequencies increased with decreasing temperature. The magnitude of the reflection coefficients was in the calculation of the unloaded Q-values. The performance of the evaporated and gold resonator are compared with the performance of a laser ablated YBa2Cu3O(7-x) resonator. The causes of the double resonance are discussed.

  11. Effect of I-shaped metamaterial on microstrip antenna

    NASA Astrophysics Data System (ADS)

    Wang, JiJun; Gong, LeiLei; Zhang, YanRong

    2015-05-01

    In this paper, a near-zero-index metamaterial is proposed by the composite I-shaped unit cell and the refraction index of this metamaterial is close to zero from 6.12GHz to 6.19 GHz. To study the characteristics and application of this near-zero-index metamaterial, especially the ability of focusing energy, a microstrip antenna is designed. According to the formulations for designing microstrip patch antenna, the conventional microstrip antenna, which resonance at 6.19GHz, is designed and optimized. This metamaterial is placed right above the conventional microstrip antenna and this system is tested by the finite element method (FEM). Simulation results show that the maximum radiation gain in H-plane of the microstrip antenna with this near-zero-index metamaterial is 9.24dB, while the maximum radiation gain in H-plane of the conventional microstrip antenna is 2.63dB, improving about 6.61dB than conventional microstrip antenna; the maximum radiation gain in E-plane of the microstrip antenna with this near-zero-index metamaterial is 9.24dB, while the maximum radiation gain in E-plane of the conventional microstrip antenna is 5.12dB, improving about 4.12dB than conventional microstrip antenna. Simulation results also show that the directivity of the microstrip antenna with this near-zero-index metamaterial is much higher, compared with the conventional microstrip antenna. Radiation gain at other frequencies, from 6.12GHz to 6.19GHz, is also obtained, the value is much higher than the conventional microstrip antenna at the corresponding frequency. The results indicate that near-zero-index metamaterials can improve the radiation gain and the directivity of the conventional microstrip antenna.

  12. Integrated optics ring-resonator chemical sensor with polymer transduction layer

    NASA Technical Reports Server (NTRS)

    Ksendzov, A.; Homer, M. L.; Manfreda, A. M.

    2004-01-01

    An integrated optics chemical sensor based on a ring resonator with an ethyl cellulose polymer coating has been demonstrated. The measured sensitivity to isopropanol in air is 50 ppm-the level immediately useful for health-related air quality monitoring. The resonator was fabricated using SiO2 and SixNy materials. The signal readout is based on tracking the wavelength of a resonance peak. The resonator layout optimisation for sensing applications is discussed.

  13. Ultra-high quality factor planar Si3N4 ring resonators on Si substrates.

    PubMed

    Tien, Ming-Chun; Bauters, Jared F; Heck, Martijn J R; Spencer, Daryl T; Blumenthal, Daniel J; Bowers, John E

    2011-07-04

    We demonstrate planar Si3N4 ring resonators with ultra-high quality factors (Q) of 19 million, 28 million, and 7 million at 1060 nm, 1310 nm, and 1550 nm, respectively. By integrating the ultra-low-loss Si3N4 ring resonators with laterally offset planar waveguide directional couplers, optical add-drop and notch filters are demonstrated to have ultra-narrow bandwidths of 16 MHz, 38 MHz, and 300 MHz at 1060 nm, 1310 nm, and 1550 nm, respectively. These are the highest Qs reported for ring resonators with planar directional couplers, and ultra-narrowband microwave photonic filters can be realized based on these high-Q ring resonators.

  14. Investigation of frequency response of microwave active ring resonator based on ferrite film

    NASA Astrophysics Data System (ADS)

    Martynov, M. I.; Nikitin, A. A.; Ustinov, A. B.; Kalinikos, B. A.

    2016-11-01

    The complex transmission coefficient of active ring resonators based on ferrite-film delay lines was investigated both theoretically and experimentally. Influence of the parameters of the delay line on the transmission coefficients was investigated. It was shown that the resonant frequencies of the ring depend on the ferrite film thickness and the distance between spin-wave antennae. These dependences give possibility to control the shape of the transmission coefficient that in combination with magnetic tuning provide flexibility for microwave applications.

  15. Electrode Placement for Active Tuning of Silicon-on-Insulator (SOI) Ring Resonator Structure Clad in Nematic Liquid Crystals

    DTIC Science & Technology

    2014-08-01

    their electromagnetic spectrum and find applications in optical switching, filtering, buffering , lasers, and biosensors. Photonic resonances are... coupler ring resonators [1–3]. Combining dielectric resonators with nematic liquid crystals (LC) enables easily tunable devices where the tuning is

  16. Entangled Photons Generation and Regeneration Using a Nonlinear Fiber Ring Resonator

    NASA Astrophysics Data System (ADS)

    Suchat, S.; Khunnam, W.; Yupapin, P. P.

    2008-11-01

    A new technique of an entangled photon pair generation and regeneration characterization using an all fiber optic scheme is investigated. The proposed system is consisted of a fiber optic ring resonator. The Kerr nonlinearity effect in the fiber ring resonator is exploited for the generation of two independent beams. The advantage of such a system is that it requires a simple arrangement without any optical pumping part and bulky optical components. Polarized light pulse trains are launched randomly into a nonlinear fiber optic ring resonator. Where the superpositions of light pulses in a nonlinear fiber optics ring resonator are randomly occurred which is formed the entangled photon pairs. A polarization controller controls polarization states of light pulses while circulating in the ring resonator. The entangled photons are seen on the avalanche photo-detector. Then the output of the entangled photon states recovery by using a fiber ring resonator incorporating an erbium-doped fiber (EDF) has been investigated. We have shown that the weak entangled photon states can be recovered after circulating in the amplified fiber optic medium. The results obtained have shown that this system can be used to achieve the recovered polarization entangled states with the obtained high gain. The amplifying noise has also been detected and seen on the spectrum output. This is affected to the entangled photon visibility, which is discussed.

  17. Tuning a racetrack ring resonator by an integrated dielectric MEMS cantilever.

    PubMed

    Abdulla, S M C; Kauppinen, L J; Dijkstra, M; de Boer, M J; Berenschot, E; Jansen, H V; de Ridder, R M; Krijnen, G J M

    2011-08-15

    The principle, fabrication and characterization of a dielectric MEMS cantilever located a few 100 nm above a racetrack ring resonator are presented. After fabrication of the resonators on silicon-on-insulator (SOI) wafers in a foundry process, the cantilevers were integrated by surface micromachining techniques. Off-state deflections of the cantilevers have been optimized to appropriately position them near the evanescent field of the resonator. Using electrostatic actuation, moving the cantilevers into this evanescent field, the propagation properties of the ring waveguide are modulated. We demonstrate 122 pm tuning of the resonance wavelength of the optical ring resonator (in the optical C-band) without change of the optical quality factor, on application of 9 V to a 40 µm long cantilever. This compact integrated device can be used for tuning/switching a specific wavelength, with very little energy for operation and negligible cross talk with surrounding devices.

  18. Fabrication of Nanopillar-Based Split Ring Resonators for Displacement Current Mediated Resonances in Terahertz Metamaterials.

    PubMed

    Liu, Chao; Schauff, Joseph; Lee, Seokhyeong; Cho, Jeong-Hyun

    2017-03-23

    Terahertz (THz) split ring resonator (SRR) metamaterials (MMs) has been studied for gas, chemical, and biomolecular sensing applications because the SRR is not affected by environmental characteristics such as the temperature and pressure surrounding the resonator. Electromagnetic radiation in THz frequencies is biocompatible, which is a critical condition especially for the application of the biomolecular sensing. However, the quality factor (Q-factor) and frequency responses of traditional thin-film based split ring resonator (SRR) MMs are very low, which limits their sensitivities and selectivity as sensors. In this work, novel nanopillar-based SRR MMs, utilizing displacement current, are designed to enhance the Q-factor up to 450, which is around 45 times higher than that of traditional thin-film-based MMs. In addition to the enhanced Q-factor, the nanopillar-based MMs induce a larger frequency shifts (17 times compared to the shift obtained by the traditional thin-film based MMs). Because of the significantly enhanced Q-factors and frequency shifts as well as the property of biocompatible radiation, the THz nanopillar-based SRR are ideal MMs for the development of biomolecular sensors with high sensitivity and selectivity without inducing damage or distortion to biomaterials. A novel fabrication process has been demonstrated to build the nanopillar-based SRRs for displacement current mediated THz MMs. A two-step gold (Au) electroplating process and an atomic layer deposition (ALD) process are used to create sub-10 nm scale gaps between Au nanopillars. Since the ALD process is a conformal coating process, a uniform aluminum oxide (Al2O3) layer with nanometer-scale thickness can be achieved. By sequentially electroplating another Au thin film to fill the spaces between Al2O3 and Au, a close-packed Au-Al2O3-Au structure with nano-scale Al2O3 gaps can be fabricated. The size of the nano-gaps can be well defined by precisely controlling the deposition cycles of the

  19. A high efficiency label-free photonic biosensor based on vertically stacked ring resonators

    NASA Astrophysics Data System (ADS)

    Campanella, C. E.; Campanella, C. M.; De Leonardis, F.; Passaro, V. M. N.

    2014-09-01

    In this paper we propose an optical biosensor based on two vertically stacked Silicon on Insulator (SOI) micro-ring resonators interacting with a microfluidic ring channel. This device behaves as a resonant optical coupler and it is very sensitive to the variation of the coupling coefficient between the two vertically stacked ring resonators. A ring microfluidic channel is proposed in the coupling region between the two vertically stacked ring resonators. The inner walls of the channel are funzionalized in order to the trap a specific biological species. Assuming a biotin-streptavidin system, the straptividin trapping gives rise to a change of the biological thickness of about 3 nm. This thickness increase of the deposited layer leads to a consequent change in the coupling strength between the two rings. These theoretical predictions have been validated by using both 3D Finite-Difference Time-Domain (FDTD) and 3D full-vectorial Finite Element Method (FEM) approaches. Moreover, by appropriately choosing the design parameters of the micro-resonant structure, we evaluate a sensitivity of the spectral response to the streptavidin adlayer variation of about 20% nm-1 for TE polarization and 34% nm-1 for TM polarization, which represents an important achievement to obtain selective SOI bio-sensors with ultra-high resolution.

  20. Analysis of ringing effects due to magnetic core materials in pulsed nuclear magnetic resonance circuits

    SciTech Connect

    Prabhu Gaunkar, N. Bouda, N. R. Y.; Nlebedim, I. C.; Hadimani, R. L.; Mina, M.; Jiles, D. C.; Bulu, I.; Ganesan, K.; Song, Y. Q.

    2015-05-07

    This work presents investigations and detailed analysis of ringing in a non-resonant pulsed nuclear magnetic resonance (NMR) circuit. Ringing is a commonly observed phenomenon in high power switching circuits. The oscillations described as ringing impede measurements in pulsed NMR systems. It is therefore desirable that those oscillations decay fast. It is often assumed that one of the causes behind ringing is the role of the magnetic core used in the antenna (acting as an inductive load). We will demonstrate that an LRC subcircuit is also set-up due to the inductive load and needs to be considered due to its parasitic effects. It is observed that the parasitics associated with the inductive load become important at certain frequencies. The output response can be related to the response of an under-damped circuit and to the magnetic core material. This research work demonstrates and discusses ways of controlling ringing by considering interrelationships between different contributing factors.

  1. Research on transmission characteristics of side-coupled rectangular-ring resonator

    NASA Astrophysics Data System (ADS)

    Cui, Luna; Yu, Li

    2016-11-01

    We investigate the characteristics of resonant modes in the side-coupled rectangular-ring resonator (SRR). The results show we can manipulate the resonant wavelengths of TMa mode and TMs mode by adjusting the outer wall width (Lx1) or the inner wall width (Lx2) of the ring resonators, and the effects of coupling distance on the full-width at half-maximum (FWHM) of resonant spectra are discussed. In sensing application, the proposed structure can work as a highly sensitive plasmonic nanosensor with a sensitivity of 1000 nm/RIU and a figure of merit (FOM) of 67. The values are comparable to periodic structures and the structures based on Fano resonance.

  2. Omnidirectional magnetic-resonance transmission and its elimination in a metallic metamaterial comprising rings and plates.

    PubMed

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

    2008-12-01

    Magnetic resonance is numerically investigated in a metallic metamaterial comprising rings and plates. It is found that a transmission band, instead of a stop band, results from the magnetic resonance as long as the electric field of the incident wave is polarized parallel to the ring plane, and thus it is an omnidirectional magnetic resonance transmission. We also observe an elimination phenomenon of the magnetic resonance transmission by tailoring the size of the plate, which implies a magnitude modulation of magnetic resonance. In addition, the equivalent LC circuit model is applied to analyze the geometry dependence of the magnetic resonance frequency, which is consistent with the numerical results by parametric simulations on the structural variations.

  3. Frequency scanning microstrip antenna (S-band)

    NASA Astrophysics Data System (ADS)

    Jayachandran, M.; Gupta, S. C.

    1983-10-01

    A frequency-scanning microstrip antenna using microstrip radiating resonators is described. The resonators are cascade-coupled. The experimental results in the S-band are in good agreement with the theory, showing that it is possible to scan the main lobe at an angle of + or - 30 deg by variation of frequency of + or - 125 MHz, where 3-dB beam width is less than 30 deg. Directivity of 12.8 dB and gain of 8.5 dB were observed.

  4. Electromagnetic interaction of split-ring resonators: The role of separation and relative orientation.

    PubMed

    Feth, Nils; König, Michael; Husnik, Martin; Stannigel, Kai; Niegemann, Jens; Busch, Kurt; Wegener, Martin; Linden, Stefan

    2010-03-29

    Extinction cross-section spectra of split-ring-resonator dimers have been measured at near-infrared frequencies with a sensitive spatial modulation technique. The resonance frequency of the dimer's coupled mode as well as its extinction cross-section and its quality factor depend on the relative orientation and separation of the two split-ring resonators. The findings can be interpreted in terms of electric and magnetic dipole-dipole interaction. Numerical calculations based on a Discontinuous Galerkin Time-Domain approach are in good agreement with the experiments and support our physical interpretation.

  5. Polymer ring resonators for high density photonic and electronic-photonic integration

    NASA Astrophysics Data System (ADS)

    Sun, Haishan

    2009-12-01

    Electrical interconnect based on the copper wires will be the bottleneck for the future performance improvement of multi-core CPUs. Chip scale optical interconnect based on high density photonic and electronic-photonic integration is one of the feasible solutions. Ring resonators are promising photonic components serving as building blocks. High density integration of ring resonators is also important for high throughput lab-on-a-chip biosensors and opto-microwave integrated circuits. Polymer materials are compatible with most semiconductor fabrication processes. Polymers can be easily doped with rare earth ions, quantum dots etc. to make active optical devices. Especially, over several hundreds pm/V electro-optic (EO) coefficients and femtosecond scale response time of EO polymers enables photonic devices with sub 1V to millivolt drive voltages and terahertz bandwidth. This dissertation describes several technologies about design, simulation, fabrication, integration with electronic circuits and fiber optics of polymer ring resonators, and demonstrates three application examples of polymer ring resonators in communications and biochemical sensing. First the Beam Propagation Method (BPM) and the matrix analysis are combined to provide a fast circuit level simulation and design procedure of polymer ring resonators. Several low cost fabrication techniques based on electron beam irradiation effects on EO polymers are introduced. For the practical electronicphotonic integration, a hybrid integration scheme of EO polymer waveguide devices with Si integrated circuits is developed. One application is an all-dielectric RF sensor or receiver with sensitivity of 100 V/m and theoretical bandwidth over 100 GHz. This device is based on a novel structure with polymer ring resonator directly coupled to a side polished optical fiber. The other two examples are biochemical sensors based on multi-slot waveguide and ring resonator reflector structures.

  6. Shielded microstrip array for 7T human MR imaging.

    PubMed

    Wu, Bing; Wang, Chunsheng; Kelley, Douglas A C; Xu, Duan; Vigneron, Daniel B; Nelson, Sarah J; Zhang, Xiaoliang

    2010-01-01

    The high-frequency transceiver array based on the microstrip transmission line design is a promising technique for ultrahigh field magnetic resonance imaging (MRI) signal excitation and reception. However, with the increase of radio-frequency (RF) channels, the size of the ground plane in each microstrip coil element is usually not sufficient to provide a perfect ground. Consequently, the transceiver array may suffer from cable resonance, lower Q-factors, and imaging quality degradations. In this paper, we present an approach to improving the performance of microstrip transceiver arrays by introducing RF shielding outside the microstrip array and the feeding coaxial cables. This improvement reduced interactions among cables, increased resonance stability, and Q-factors, and thus improved imaging quality. An experimental method was also introduced and utilized for quantitative measurement and evaluation of RF coil resonance stability or "cable resonance" behavior.

  7. A reconfigurable subwavelength plasmonic fano nano-antenna based on split ring resonator

    NASA Astrophysics Data System (ADS)

    Hosseinbeig, Ahmad; Pirooj, Azadeh; Zarrabi, Ferdows B.

    2017-02-01

    In this article, a reconfigurable subwavelength plasmonic nano-antenna with Fano resonance effect is presented based on the dual ring structure. In order to achieve reconfigurable characteristics, the interaction of gold with graphene is studied. SiN substrate with refractive index of 1.98 and gold with Palik optical characteristic modified for metal layer are utilized in the design of the proposed nano-antenna. Simulations are performed by using CST Microwave Studio. The biasing effect on extinction cross section is studied for 0 to 0.8 eV. It is shown that the gap method is useful for exciting the Fano resonance in the dual ring nano-antenna and there is only a plasmonic resonance in the simple dual ring antenna. The proposed nano-antenna is useful for THz medical spectroscopy due to its simple design and the ability to control the second resonance frequency by changing the bias of the graphene.

  8. Output switching in a semiconductor circular ring resonator due to solitons wave formation

    NASA Astrophysics Data System (ADS)

    Shih, Ming Chang; Yen, Chun Liang

    2014-01-01

    Here we demonstrated the phenomena of switching of the coupling in an InGaAlP multiple-quantum-well semiconductor circular ring resonator due to the generation of solitons wave guiding. The fabricated device is consisted of a circular ridge waveguide ring resonator with diameter range from 150 to 250 µm with two Y-junction directional couplers for output coupling of clockwise/counter clockwise (CW/CCW) modes. Ridge waveguide of 1.1 and 0.8 µm depth were fabricated to study the effect in solitons generation. It showed that for the 1.1 µm etched depth waveguide, CW and CCW modes in the ring resonator were coupled out through each Y-junction couplers respectively. However, for the 0.8 µm depth waveguide when spatial solitons was formed, coupling of the CCW modes in the circular ring resonator was switched from Y-junction coupler to the spatial solitons guiding terminal. Measurements of light-current (L-I) and spectral characteristics were studied to enunciate the mechanism of output modes switching in circular ring resonator.

  9. Flexible microstrip antennas

    NASA Astrophysics Data System (ADS)

    Cano Barrera, Camilo Antonio

    2013-05-01

    Actually the technological community has an interest in developing flexible circuits and antennas with particular characteristics e.g. robust, flexible, lightweight load-bearing, economical and efficient antennas for integrated millimeter wave systems. Microstrip antennas are an excellent solution because those have all the characteristics before mentioned, but they have the problem of being rigid antennas and this makes impossible that those antennas can be use in portable devices. A practical solution is developing flexible microstrip antennas that can be integrated to different devices. One axis of work is the analysis of the electromagnetic field to the microstrip antennas using Bessel function and after generalize for application inflexible microstrip antennas.

  10. Ultraclean wafer-level vacuum-encapsulated silicon ring resonators for timing and frequency references

    NASA Astrophysics Data System (ADS)

    Xereas, George; Chodavarapu, Vamsy P.

    2016-07-01

    We present the design and development of breath-mode silicon ring resonators fabricated using a commercial pure-play microfabrication process that provides ultraclean wafer-level vacuum-encapsulation. The micromechanical resonators are fabricated in MEMS integrated design for inertial sensors process that is developed by Teledyne DALSA Semiconductor Inc. The ring resonators are designed to operate with a relatively low DC polarization voltage, starting at 5 V, while providing a high frequency-quality factor product. We study the quality of the vacuum packaging using an automated testing setup over an extended time period. We study the effect of motional resistance on the performance of MEMS resonators. The fabricated devices had a resonant frequency of 10 MHz with the quality factor exceeding 8.4×104.

  11. Multi-gap individual and coupled split-ring resonator structures.

    PubMed

    Penciu, R S; Aydin, K; Kafesaki, M; Koschny, Th; Ozbay, E; Economou, E N; Soukoulis, C M

    2008-10-27

    We present a systematic numerical study, validated by accompanied experimental data, of individual and coupled split ring resonators (SRRs) of a single rectangular ring with one, two and four gaps. We discuss the behavior of the magnetic resonance frequency, the magnetic field and the currents in the SRRs, as one goes from a single SRR to strongly interacting SRR pairs in the SRR plane. We show that coupling of the SRRs along the E direction results to shift of the magnetic resonance frequency to lower or higher values, depending on the capacitive or inductive nature of the coupling. Strong SRR coupling along propagation direction usually results to splitting of the single SRR resonance into two distinct resonances, associated with peculiar field and current distributions.

  12. Resonant Transmission of Electron Spin States through Multiple Aharonov-Bohm Rings

    NASA Astrophysics Data System (ADS)

    Cutright, Jim; Hedin, Eric; Joe, Yong

    2011-10-01

    An Aharonov-Bohm (AB) ring with embedded quantum dots (QD) in each arm and one -dimensional nanowires attached as leads acts as a primitive cell in this analysis. When a tunable, external magnetic field is parallel to the surface area of the ring it causes Zeeman splitting in the energy levels of the QDs. An electron that traverses these energy levels has the potential to interfere with other electrons and to produce spin polarized output. It is already known that upon output the transmission of the electrons through this system will have a resonant peak at each Zeeman split energy level. A system where multiple AB rings are connected in series is studied, to see how having the electrons pass through multiple, identical rings effects the resonant peaks in the transmission and the degree of spin polarization.

  13. Strong diamagnetic response in split-ring-resonator metamaterials: Numerical study and two-loop model

    SciTech Connect

    Economou, E.; Koschny, T.; Souloulis, C.

    2008-03-03

    We demonstrate that there is a strong diamagnetic response of metamaterials, consisting of open or closed split-ring resonators (SRRs). Detailed numerical work shows that for densely packed SRRs, the magnetic permeability {mu}({omega}) does not approach unity, as expected for frequencies lower and higher than the resonance frequency {omega}{sub 0}. Below {omega}{sub 0}, {mu}({omega}) gives values ranging from 0.9 to 0.6 depending of the width of the metallic ring, while above {omega}{sub 0}, {mu}({omega}) is close to 0.5. Closed rings have {mu} {approx} 0.5 over a wide frequency range independently of the width of the ring. A simple model that uses the inner and outer current loops of the SRRs can easily explain theoretically this strong diamagnetic response, which can be used in magnetic levitation.

  14. Strong diamagnetic response in split-ring-resonator metamaterials: Numerical study and two-loop model

    NASA Astrophysics Data System (ADS)

    Economou, E. N.; Koschny, Th.; Soukoulis, C. M.

    2008-03-01

    We demonstrate that there is a strong diamagnetic response of metamaterials, consisting of open or closed split-ring resonators (SRRs). Detailed numerical work shows that for densely packed SRRs, the magnetic permeability μ(ω) does not approach unity, as expected for frequencies lower and higher than the resonance frequency ω0 . Below ω0 , μ(ω) gives values ranging from 0.9 to 0.6 depending of the width of the metallic ring, while above ω0 , μ(ω) is close to 0.5. Closed rings have μ≈0.5 over a wide frequency range independently of the width of the ring. A simple model that uses the inner and outer current loops of the SRRs can easily explain theoretically this strong diamagnetic response, which can be used in magnetic levitation.

  15. Resonant condition for storage ring short wavelength FEL with power exceeding Renieri limit

    SciTech Connect

    Litvinenko, V.N.; Burnham, B.; Wu, Y.

    1995-12-31

    In this paper we discuss the possibility of operating a storage ring FEL with resonant conditions providing for preservation of electron beam structure on an optical wave scale. We suggest tuning the storage ring betatron and synchrotron tunes on one of the high (N-th) order resonances to compensate dynamic diffusion of optical phase. This mode of operation does not require isochronicity of the ring lattice. In these conditions optical phase will be restored after N turns around the ring and stochastic conditions used in the derivation of Renieri limit are no longer applicable. We discuss the influence of high order terms in electron motion, RF frequency stability, and synchrotron radiation effects on preservation of optical phase.

  16. Triband phase shifter design using split-ring resonator and complementary split-ring resonator-loaded ground plane for wireless applications

    NASA Astrophysics Data System (ADS)

    Kulandhaisamy, Indhumathi; Shrivastav, Arun Kumar; Kanagasabai, Malathi; Kizhekke Pakkathillam, Jayaram

    2015-10-01

    This paper presents the design of a novel linear analog planar phase shifter deploying split-ring resonator (SRR) and complementary split-ring resonator (CSRR) structures. Based on the advantages of these structures, a triband phase shifter is designed for multiple target systems to operate at 0.85, 1.69, and 2.46 GHz bands finding applications for European RFIDs, Satellite Radio Broadcast System, Mobile Services, and ISM Band, respectively. The effect of SRR and CSRR coupling with host transmission line is also analyzed on the basis of Bloch mode theory and the modes are validated through Eigen mode analysis. The proposed phase shifter design shows a good agreement between simulated and measured results. A 90° ± 8° shift in phase is observed at lower and upper bands, and a 135° ± 8° shift is observed in center band with reasonable group delay components.

  17. Causal information velocity in fast and slow pulse propagation in an optical ring resonator

    SciTech Connect

    Tomita, Makoto; Uesugi, Hiroyuki; Sultana, Parvin; Oishi, Tohru

    2011-10-15

    We examined the propagation of nonanalytical points encoded on temporally Gaussian-shaped optical pulses in fast and slow light in an optical ring resonator at {lambda} = 1.5 {mu}m. The temporal peak of the Gaussian pulse was either advanced or delayed, reflecting anomalous or normal dispersions in the ring resonator, relevant to under- or overcoupling conditions, respectively. The nonanalytical points were neither advanced nor delayed but appeared as they entered the ring resonator. The nonanalytical points could be interpreted as information; therefore, the experimental results suggested that information velocity is equal to the light velocity in vacuum or the background medium, independent of the group velocity. The transient behaviors at the leading and trailing edges of the nonanalytical points are discussed in terms of optical precursors.

  18. Fiber ring laser for intracavity sensing using a whispering-gallery-mode resonator.

    PubMed

    Nunzi Conti, G; Berneschi, S; Barucci, A; Cosi, F; Soria, S; Trono, C

    2012-07-01

    Whispering-gallery-mode (WGM) microresonators are used as optical transducers for sensing applications. The typical detection scheme is based on tracking the WGM resonance shift, by scanning with a tunable laser, when a change of the refractive index in the region probed by the WGM takes place. We propose a sensing approach based instead on monitoring the position of the laser line of a fiber ring laser having a WGM microsphere in its loop. We have demonstrated that the induced shift is the same for the ring laser line and for the microsphere resonance. The proposed method requires simpler, cheaper equipment and may also improve the sensor resolution because the ring laser line is much narrower than the microsphere WGM resonance.

  19. Compensating thermal drift of hybrid silicon and lithium niobate ring resonances.

    PubMed

    Chen, Li; Wood, Michael G; Reano, Ronald M

    2015-04-01

    We present low-power compensation of thermal drift of resonance wavelengths in hybrid silicon and lithium niobate ring resonators based on the linear electro-optic effect. Fabricated devices demonstrate a resonance wavelength tunability of 12.5  pm/V and a tuning range of 1 nm. A capacitive geometry and low thermal sensitivity result in the compensation of 17°C of temperature variation using tuning powers at sub-nanowatt levels. The method establishes a route for stabilizing high-quality factor resonators in chip-scale integrated photonics subject to temperature variations.

  20. Design and characterization of a novel toroidal split-ring resonator

    NASA Astrophysics Data System (ADS)

    Bobowski, J. S.; Nakahara, Hiroko

    2016-02-01

    The design and characterization of a novel toroidal split-ring resonator (SRR) are described in detail. In conventional cylindrical SRRs, there is a large magnetic flux within the bore of the resonator. However, there also exists a non-negligible magnetic flux in the free space surrounding the resonator. The energy losses associated with this radiated power diminish the resonator's quality factor. In the toroidal SRR, on the other hand, the magnetic field lines are strongly confined within the bore of the resonator resulting in high intrinsic quality factors and stable resonance frequencies without requiring additional electromagnetic shielding. This paper describes the design and construction of a toroidal SRR as well as an experimental investigation of its cw response in the frequency-domain and its time-domain response to a rf pulse. Additionally, the dependence of the toroidal SRR's resonant frequency and quality factor on the strength of inductive coupling to external circuits is investigated both theoretically and experimentally.

  1. Tuneable Meta-Material Split-Ring Resonators for Impedance Matching Antennas for Broadband Applications

    DTIC Science & Technology

    2008-12-01

    used in the design of antennas in order to miniaturize antenna size while preserving its frequency of operation, by way of inductively loading the...modified to a single ring configuration as shown in Fig. 1(a). The SRRs are in-plane with the loop antenna for miniaturization and tuning of the antenna ...1 TUNEABLE META-MATERIAL SPLIT-RING RESONATORS FOR IMPEDANCE MATCHING ANTENNAS FOR BROADBAND APPLICATIONS Chunchen Lin, Iftekhar O. Mirza

  2. Analysis of microstrip lines with alternative implementation of conductors and superconductors

    NASA Technical Reports Server (NTRS)

    Kong, K.-S.; Lee, H.-Y.; Itoh, T.; Chorey, C. M.; Bhasin, K. B.

    1990-01-01

    An analysis of microstrip line structures in which either the strip or the ground plane or both are made of a high Tc superconductor is presented. The effect of implementation of a superconductor to the strip and the ground plane is explained with the calculation of a conductor loss of the structure by the Phenomenological Loss Equivalence Method (PEM). The theoretical values are compared with the experimental results from a ring resonator which is made of a gold ground plane and a high Tc superconductor, YBa2Cu3O(7-x), strip.

  3. Label-free detection with the liquid core optical ring resonator sensing platform

    PubMed Central

    White, Ian M.; Zhu, Hongying; Suter, Jonathan D.; Fan, Xudong; Zourob, Mohammed

    2009-01-01

    Optical label-free detection avoids the cost and complexity of fluorescence and radio labeling while providing accurate quantitative and kinetic results. We have developed a new optical label-free sensor called the liquid core optical ring resonator (LCORR). The LCORR integrates optical ring resonator sensors into the microfluidic delivery system by using glass capillaries with a thin wall. The LCORR is capable of performing refractive index detection on liquid samples, as well as bio/chemical analyte detection down to detection limits on the scale of pg/mm2. PMID:19151939

  4. Transient radiation from a ring resonant medium excited by an ultrashort superluminal pulse

    SciTech Connect

    Arkhipov, R M; Arkhipov, M V; Tolmachev, Yu A; Babushkin, I V

    2015-06-30

    We report some specific features of transient radiation from a periodic spatially modulated one-dimensional medium with a resonant response upon excitation by an ultrashort pulse. The case of ring geometry (with particle density distributed along the ring according to the harmonic law) is considered. It is shown that the spectrum of scattered radiation contains (under both linear and nonlinear interaction), along with the frequency of intrinsic resonance of the medium, a new frequency, which depends on the pulse velocity and the spatial modulation period. The case of superluminal motion of excitation, when the Cherenkov effect manifests itself, is also analysed. (laser applications and other topics in quantum electronics)

  5. Ring Resonator for Detection of Melting Brine Under Shallow Subsurface of Mars

    NASA Technical Reports Server (NTRS)

    Ponchak, George E.; Jordan, Jennifer L.; Scardelletti, Maximillian C.

    2016-01-01

    Laboratory experimental evidence using Raman spectroscopy has shown that liquid brine may form below the shallow subsurface of Mars. A simpler experimental method to verify the presence of liquid brine or liquid water below Mars surface is needed. In this paper, a ring resonator is used to detect the phase change between frozen water and liquid water below a sandy soil that simulates the Mars surface. Experimental data shows that the ring resonator can detect the melting of thin layers of frozen brine or water up to 15 mm below the surface.

  6. Ultra-low power generation of twin photons in a compact silicon ring resonator.

    PubMed

    Azzini, Stefano; Grassani, Davide; Strain, Michael J; Sorel, Marc; Helt, L G; Sipe, J E; Liscidini, Marco; Galli, Matteo; Bajoni, Daniele

    2012-10-08

    We demonstrate efficient generation of correlated photon pairs by spontaneous four wave mixing in a 5 μm radius silicon ring resonator in the telecom band around 1550 nm. By optically pumping our device with a 200 μW continuous wave laser, we obtain a pair generation rate of 0.2 MHz and demonstrate photon time correlations with a coincidence-to-accidental ratio as high as 250. The results are in good agreement with theoretical predictions and show the potential of silicon micro-ring resonators as room temperature sources for integrated quantum optics applications.

  7. Overview of novel integrated optical ring resonator bio/chemical sensors

    NASA Astrophysics Data System (ADS)

    Fan, Xudong; White, Ian M.; Zhu, Hongying; Suter, Jonanthan D.; Oveys, Hesam

    2007-02-01

    In parallel to a stand-alone microsphere resonator and a planar ring resonator on a wafer, the liquid core optical ring resonator (LCORR) is regarded as the third type of ring resonator that integrates microfluidics with state-of-the-art photonics. The LCORR employs a micro-sized glass capillary with a wall thickness of a few microns. The circular cross section of the capillary forms a ring resonator that supports the whispering gallery modes (WGMs), which has the evanescent field in the core, allowing for repetitive interaction with the analytes carried inside the capillary. Despite the small physical size of the LCORR and sub-nanoliter sensing volume, the effective interaction length can exceed 10 cm due to high Q-factor (10 6), significantly improving the LCORR detection limit. The LCORR is a versatile system that exhibits excellent fluid handling capability inherent to capillaries and permits non-invasive and quantitative measurement at any location along the capillary. Furthermore, the LCORR uses the refractive index change as a transduction signal, which enables label-free detection. Therefore, the LCORR is a promising technology platform for future sensitive, miniaturized, lab-on-a-chip type sensors. In this paper, we will introduce the concept of the LCORR and present the theoretical analysis and the experimental results related to the LCORR sensor development.

  8. Generating and manipulating higher order Fano resonances in dual-disk ring plasmonic nanostructures.

    PubMed

    Fu, Yuan Hsing; Zhang, Jing Bo; Yu, Ye Feng; Luk'yanchuk, Boris

    2012-06-26

    In this article, we investigate higher order (quadrupolar, octupolar, hexadecapolar, and triakontadipolar) Fano resonances generated in disk ring (DR) silver plasmonic nanostructures. We find that the higher order Fano resonances are generated when the size of the disk is reduced and falls into a certain range. With dual-disk ring (DDR) nanostructures, a rich set of tunable Fano line shapes is provided. More specifically, we report our observations on the optical behavior of the DDRs including asymmetric cases either in two disks with different sizes or their asymmetric locations inside the ring. In the case of symmetric dual-disk ring (SDDR) nanostructures, we demonstrate that the quadrupolar and the hexadecapolar Fano resonances are suppressed, which can reduce the cross-talk in spectroscopic measurements, while the octupolar and the triakontadipolar Fano resonances are enhanced. The potential of using the studied plasmonic nanostructures as biochemical sensors is evaluated with the figure of merit (FOM) and the contrast ratio (CR). The values of the FOM and the CR achieved using the triakontadipolar Fano resonance in the SDDR are 17 and 57%, respectively. These results indicate that the SDDRs could be developed into a high-performance biochemical sensor in the visible wavelength range.

  9. Rotation sensing with Er3+-doped active ring resonator slow light structure

    NASA Astrophysics Data System (ADS)

    Gu, Hong; Liu, Xiaoqin

    2016-10-01

    An optical gyroscope, which is constituted by Er3+-doped active ring resonator (EDARR) slow light structure, is presented for the first time. The principle of improving the sensitivity of the detection of angular velocity is analysed in detail. The expression of the rotation phase difference of EDARR between the counter-propagating waves is derived and discussed. At the resonant frequency, the phase shift difference has the maximum value when the light power in the cavity is far greater than the input light power. We designed an experimental scheme of Er3+-doped active ring resonator slow light system. Two additional bias phases ϕb = ±π/2 were introduced in the optical path, by recording the light intensity difference ? and I0 at the resonant frequency ?, the input angular velocity can be obtained. The slow light structure based on EDARR can enhance the sensitivity of the detection of the angular velocity by three orders of magnitude.

  10. Retarded long-range interaction in split-ring-resonator square arrays

    NASA Astrophysics Data System (ADS)

    Decker, Manuel; Feth, Nils; Soukoulis, Costas M.; Linden, Stefan; Wegener, Martin

    2011-08-01

    We systematically investigate the optical extinction spectra of planar gold split-ring-resonator square arrays operating at ˜200-THz frequency versus the lattice constant and versus angle of incidence. We find a strong dependence of the resonance damping on the in-plane wave vector, namely, the resonance damping increases (decreases) versus the in-plane wave vector for small lattice constants (large lattice constants). By comparison with two simple one-dimensional models as well as with more complete numerical calculations, this behavior is interpreted in terms of a long-range retarded interaction among the split-ring resonators. In contrast, the assumptions of only nearest-neighbor interaction and/or of an instantaneous interaction lead to a striking disagreement with the overall experimental facts.

  11. High-order micro-ring resonator with perfect transmission using symmetrical Fibonacci structures.

    PubMed

    Tsao, C W; Cheng, Y H; Hsueh, W J

    2015-09-15

    A symmetrical Fibonacci micro-ring resonator (SFMR) has been presented to avoid the coupled resonator optical waveguide (CROW) bottle, which is a bottle-shaped distribution for high orders in transmission spectra. The SFMR features three advantages that improve filtering quality compared to that provided by traditional periodic micro-ring resonators. First, sharper resonances are obtained by eliminating the CROW bottle from the mini gaps that appear in the major-band region. Second, peaks with perfect transmission are always obtained without a radius and coupling modulation in the mini-band regions and major-band regions. Third, the full width at half-maximum of the band-edge peak decreases with the increasing generation order.

  12. Observation of Magnetic Resonances in Electron Clouds in a Positron Storage Ring

    SciTech Connect

    Pivi, M.T.F.; Ng, J.S.T.; Cooper, F.; Kharakh, D.; King, F.; Kirby, R.E.; Kuekan, B.; Spencer, Cherrill M.; Raubenheimer, T.O.; Wang, L.F.; /SLAC

    2011-08-24

    The first experimental observation of magnetic resonances in electron clouds is reported. The resonance was observed as a modulation in cloud intensity for uncoated as well as TiN-coated aluminum surfaces in the positron storage ring of the PEP-II collider at SLAC. Electron clouds frequently arise in accelerators of positively charged particles, and severely impact the machines performance. The TiN coating was found to be an effective remedy, reducing the cloud intensity by three orders of magnitude.

  13. Microstrip antennas and arrays on chiral substrates

    NASA Astrophysics Data System (ADS)

    Pozar, David M.

    1992-10-01

    Results are presented for isolated microstrip antennas and infinite arrays of microstrip antennas printed on chiral substrates, computed from full-wave spectral domain moment method solutions. Data for resonant length, impedance, directivity, efficiency, cross-polarization level, and scan performance are given, and compared to results obtained for a dielectric substrate of the same thickness and permittivity. It is concluded that, from the point of view of antenna characteristics, there does not seem to be any advantage to using chiral antenna substrates, while there are disadvantages in terms of increased cross-pol levels and losses due to surface wave excitation.

  14. Achieving a multi-band metamaterial perfect absorber via a hexagonal ring dielectric resonator

    NASA Astrophysics Data System (ADS)

    Li, Li-Yang; Wang, Jun; Du, Hong-Liang; Wang, Jia-Fu; Qu, Shao-Bo

    2015-06-01

    A multi-band absorber composed of high-permittivity hexagonal ring dielectric resonators and a metallic ground plate is designed in the microwave band. Near-unity absorptions around 9.785 GHz, 11.525 GHz, and 12.37 GHz are observed for this metamaterial absorber. The dielectric hexagonal ring resonator is made of microwave ceramics with high permittivity and low loss. The mechanism for the near-unity absorption is investigated via the dielectric resonator theory. It is found that the absorption results from electric and magnetic resonances where enhanced electromagnetic fields are excited inside the dielectric resonator. In addition, the resonance modes of the hexagonal resonator are similar to those of standard rectangle resonators and can be used for analyzing hexagonal absorbers. Our work provides a new research method as well as a solid foundation for designing and analyzing dielectric metamaterial absorbers with complex shapes. Project supported by the National Natural Science Foundation of China (Grant Nos. 61331005, 11204378, 11274389, 11304393, and 61302023), the Aviation Science Foundation of China (Grant Nos. 20132796018 and 20123196015), the Natural Science Foundation for Post-Doctoral Scientists of China (Grant Nos. 2013M532131 and 2013M532221), the Natural Science Foundation of Shaanxi Province, China (Grant No. 2013JM6005), and the Special Funds for Authors of Annual Excellent Doctoral Degree Dissertations of China (Grant No. 201242).

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

    NASA Astrophysics Data System (ADS)

    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.

  16. Analysis of microstrip antennas using magnetic substrates

    NASA Astrophysics Data System (ADS)

    Vakati, Venkata Jagadish Prasad

    The substrate materials play a major role in the design, production and, most importantly, the performance of the Microstrip antennas. The main goal of this thesis lies in performing a comprehensive and exhaustive study as well as an analysis of how magnetic substrates affect the performance indices of the Microstrip antennas. This project takes into consideration the fact that study of magnetic materials as substrates is a relatively uncharted territory and that a few studies into this field have shown many potential facts. This project narrows the antenna under study to a rectangular Microstrip antenna, due to both the simplicity and the versatility of this structure and the scalability of the study. The project was performed using simulation of Microstrip antenna in CST Microwave Studio with magnetic substrates, over a range of mur, and recording the performance indices of the antenna. The performance indices that were considered for the study were Directivity, Efficiency, Gain, Bandwidth, Resonant frequency and VSWR. The method followed in this study can be easily scaled further to accommodate more performance indices, if needed. The observations were later used to draw practical inferences. Also as an extension, wide band 2x2 Microstrip antenna is designed with an additional degree of freedom where changing the feed distance can cover different bands in GSM frequency.

  17. Chiral metamaterials with negative refractive index based on four “U” split ring resonators

    SciTech Connect

    Li, Zhaofeng; Zhao, Rongkuo; Koschny, Thomas; Kafesaki, Maria; Alici, Kamil Boratay; Colak, Evrim; Caglayan, Humeyra; Ozbay, Ekmel; Soukoulis, C.M.

    2010-08-23

    A uniaxial chiral metamaterial is constructed by double-layered four 'U' split ring resonators mutually twisted by 90{sup o}. It shows a giant optical activity and circular dichroism. The retrieval results reveal that a negative refractive index is realized for circularly polarized waves due to the large chirality. The experimental results are in good agreement with the numerical results.

  18. Fusion of Renewable Ring Resonator Lasers and Ultrafast Laser Inscribed Photonic Waveguides

    NASA Astrophysics Data System (ADS)

    Chandrahalim, Hengky; Rand, Stephen C.; Fan, Xudong

    2016-09-01

    We demonstrated the monolithic integration of reusable and wavelength reconfigurable ring resonator lasers and waveguides of arbitrary shapes to out-couple and guide laser emission on the same fused-silica chip. The ring resonator hosts were patterned by a single-mask standard lithography, whereas the waveguides were inscribed in the proximity of the ring resonator by using 3-dimensional femtosecond laser inscription technology. Reusability of the integrated ring resonator – waveguide system was examined by depositing, removing, and re-depositing dye-doped SU-8 solid polymer, SU-8 liquid polymer, and liquid solvent (toluene). The wavelength reconfigurability was validated by employing Rhodamine 6G (R6G) and 3,3‧-Diethyloxacarbocyanine iodide (CY3) as exemplary gain media. In all above cases, the waveguide was able to couple out and guide the laser emission. This work opens a door to reconfigurable active and passive photonic devices for on-chip coherent light sources, optical signal processing, and the investigation of new optical phenomena.

  19. Reconfigurable Solid-state Dye-doped Polymer Ring Resonator Lasers

    NASA Astrophysics Data System (ADS)

    Chandrahalim, Hengky; Fan, Xudong

    2015-12-01

    This paper presents wavelength configurable on-chip solid-state ring lasers fabricated by a single-mask standard lithography. The single- and coupled-ring resonator hosts were fabricated on a fused-silica wafer and filled with 3,3‧-Diethyloxacarbocyanine iodide (CY3), Rhodamine 6G (R6G), and 3,3‧-Diethylthiadicarbocyanine iodide (CY5)-doped polymer as the reconfigurable gain media. The recorded lasing threshold was ~220 nJ/mm2 per pulse for the single-ring resonator laser with R6G, marking the lowest threshold shown by solid-state dye-doped polymer lasers fabricated with a standard lithography process on a chip. A single-mode lasing from a coupled-ring resonator system with the lasing threshold of ~360 nJ/mm2 per pulse was also demonstrated through the Vernier effect. The renewability of the dye-doped polymer was examined by removing and redepositing the dye-doped polymer on the same resonator hosts for multiple cycles. We recorded consistent emissions from the devices for all trials, suggesting the feasibility of employing this technology for numerous photonic and biochemical sensing applications that entail for sustainable, reconfigurable, and low lasing threshold coherent light sources on a chip.

  20. Demonstration of polarization mode selection and coupling efficiency of optofluidic ring resonator lasers.

    PubMed

    Zhang, Yuanxian; Meng, Weidong; Yang, Hongyue; Chu, Yufei; Pu, Xiaoyun

    2015-11-01

    We demonstrate the polarization mode selection and the dependence of coupling efficiency on polarization state of pump light for an optofluidic ring resonator (OFRR) laser. An optical fiber is chosen to serve as the ring resonator and surrounded by rhodamine 6G dye solution of lower refractive index as the fluidic gain medium. When the ring resonator is pumped by a linearly s-polarized laser, the emitted whispering gallery mode (WGM) lasing is of parallel polarization (TM mode), while p-polarized laser excitation generates a vertically polarized lasing emission (TE mode), both TM and TE mode lasing emission coexist simultaneously if the ring resonator is pumped by the s- and p-mixed polarized light. Further investigation reveals that the lasing intensity of the TM mode is approximately twice that of the TE mode for the same pump energy density, meaning an obvious difference of coupling efficiency on the polarization state of pump light; the experimental results of coupling efficiency are well explained by an induced dipole model.

  1. Reconfigurable Solid-state Dye-doped Polymer Ring Resonator Lasers.

    PubMed

    Chandrahalim, Hengky; Fan, Xudong

    2015-12-17

    This paper presents wavelength configurable on-chip solid-state ring lasers fabricated by a single-mask standard lithography. The single- and coupled-ring resonator hosts were fabricated on a fused-silica wafer and filled with 3,3'-Diethyloxacarbocyanine iodide (CY3), Rhodamine 6G (R6G), and 3,3'-Diethylthiadicarbocyanine iodide (CY5)-doped polymer as the reconfigurable gain media. The recorded lasing threshold was ~220 nJ/mm(2) per pulse for the single-ring resonator laser with R6G, marking the lowest threshold shown by solid-state dye-doped polymer lasers fabricated with a standard lithography process on a chip. A single-mode lasing from a coupled-ring resonator system with the lasing threshold of ~360 nJ/mm(2) per pulse was also demonstrated through the Vernier effect. The renewability of the dye-doped polymer was examined by removing and redepositing the dye-doped polymer on the same resonator hosts for multiple cycles. We recorded consistent emissions from the devices for all trials, suggesting the feasibility of employing this technology for numerous photonic and biochemical sensing applications that entail for sustainable, reconfigurable, and low lasing threshold coherent light sources on a chip.

  2. Reconfigurable Solid-state Dye-doped Polymer Ring Resonator Lasers

    PubMed Central

    Chandrahalim, Hengky; Fan, Xudong

    2015-01-01

    This paper presents wavelength configurable on-chip solid-state ring lasers fabricated by a single-mask standard lithography. The single- and coupled-ring resonator hosts were fabricated on a fused-silica wafer and filled with 3,3′-Diethyloxacarbocyanine iodide (CY3), Rhodamine 6G (R6G), and 3,3′-Diethylthiadicarbocyanine iodide (CY5)-doped polymer as the reconfigurable gain media. The recorded lasing threshold was ~220 nJ/mm2 per pulse for the single-ring resonator laser with R6G, marking the lowest threshold shown by solid-state dye-doped polymer lasers fabricated with a standard lithography process on a chip. A single-mode lasing from a coupled-ring resonator system with the lasing threshold of ~360 nJ/mm2 per pulse was also demonstrated through the Vernier effect. The renewability of the dye-doped polymer was examined by removing and redepositing the dye-doped polymer on the same resonator hosts for multiple cycles. We recorded consistent emissions from the devices for all trials, suggesting the feasibility of employing this technology for numerous photonic and biochemical sensing applications that entail for sustainable, reconfigurable, and low lasing threshold coherent light sources on a chip. PMID:26674508

  3. Fusion of Renewable Ring Resonator Lasers and Ultrafast Laser Inscribed Photonic Waveguides

    PubMed Central

    Chandrahalim, Hengky; Rand, Stephen C.; Fan, Xudong

    2016-01-01

    We demonstrated the monolithic integration of reusable and wavelength reconfigurable ring resonator lasers and waveguides of arbitrary shapes to out-couple and guide laser emission on the same fused-silica chip. The ring resonator hosts were patterned by a single-mask standard lithography, whereas the waveguides were inscribed in the proximity of the ring resonator by using 3-dimensional femtosecond laser inscription technology. Reusability of the integrated ring resonator – waveguide system was examined by depositing, removing, and re-depositing dye-doped SU-8 solid polymer, SU-8 liquid polymer, and liquid solvent (toluene). The wavelength reconfigurability was validated by employing Rhodamine 6G (R6G) and 3,3′-Diethyloxacarbocyanine iodide (CY3) as exemplary gain media. In all above cases, the waveguide was able to couple out and guide the laser emission. This work opens a door to reconfigurable active and passive photonic devices for on-chip coherent light sources, optical signal processing, and the investigation of new optical phenomena. PMID:27600872

  4. Ultra-sensitive silicon photonic current sensor using a ring resonator

    NASA Astrophysics Data System (ADS)

    Wei, Bing; Zhao, Changyun; Wang, Gencheng; Dai, Tingge; Wang, Yuehai; Yang, Jianyi; Li, Yubo

    2016-08-01

    We proposed and experimentally investigated a compact and ultra-sensitive integrated photonic current sensor based on a silicon ring resonator in this paper. The current flowing through the integrated resistive TiN heater produces the Joule’s heat and changes the temperature, which results in the change of refractive index and physical dimensions of the ring. An optical spectrum analyzer is used to monitor the resonant wavelength shift of the ring. The experiment results show that the sensor achieves an ultra-high sensitivity of 6.8 × 104 nm A-2 and good linearity between real-time current and wavelength shift in the test range of 0-10 mA.

  5. Tunable band notch filters by manipulating couplings of split ring resonators.

    PubMed

    Sun, Haibin; Wen, Guangjun; Huang, Yongjun; Li, Jian; Zhu, Weiren; Si, Li-Ming

    2013-11-01

    The couplings between single/dual split ring resonators (SRRs) and their mirror images in a rectangular waveguide are systematically investigated through theoretical analysis and experimental measurements. Such couplings can be manipulated mechanically by rotating the SRRs along a dielectric rod and/or shifting the SRRs up/down along the sidewall of the rectangular waveguide, resulting in shifts of the resonant frequencies and modulations of the resonant magnitudes. These controllable properties of SRRs pave the routers toward designing tunable band notch filters. In particular, it is experimentally demonstrated that the designed filters possess 7.5% tuning range in the X-band.

  6. Tunable and flat optical delay line based on double rings resonators

    NASA Astrophysics Data System (ADS)

    Qi, Kaiyue; Zhang, Yundong; Wu, Yongfeng; Li, Hui; Yuan, Ping

    2016-11-01

    We theoretically investigate a basic structure that the series-coupled double ring resonator coupled two straight waveguide. We calculate the transmission function and phase shift through transfer matrix theory .The system consists of two rings, three straight waveguide and four couplers which the drop port and the though port are coupled to a bus waveguide .We obtain a tunable flat delay line which mitigates the deleterious effects of group delay dispersion in this structure through adjusting 4 coupling coefficient of the couplers, the attenuation factor of ring waveguide and the perimeter of 2 rings. The ability to realize the phenomenon is important for applications such as optical switching, and tunable bandwidth filter applications.

  7. Flexible printed chipless RFID tag using metamaterial-split ring resonator

    NASA Astrophysics Data System (ADS)

    Jalil, M. E.; Rahim, M. K. A.; Samsuri, N. A.; Dewan, R.

    2016-04-01

    An 8-bit passive chipless RFID using metamaterial structure with dimension of 25 × 50 mm which operates between 3.4 and 7.4 GHz is proposed. The chipless RFID is designed using complementary split ring resonator (SRR) with a transmission line feeding network of 50 Ω. The modified complementary split ring resonator (MCSRR) is located at the backside of the substrate. The MCSRR has narrow bandwidth which can maximize the amount of bit capacity. To enhance the bit capacity, the frequency shifting is introduced by the allocation of bit conditions (00, 01, 10 and 11) at the specific resonance frequency. The polyethylene terephthalate material with ɛ r = 3.0 and tan δ = 0.002 is a suitable candidate for body identification due to the flexibility and the robustness of the material.

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

    NASA Astrophysics Data System (ADS)

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

    2017-01-01

    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.

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

    PubMed

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

    2017-01-01

    We experimentally realize an optical fiber ring resonator that includes a tapered section with a 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 the 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.

  10. A new model for broadband waveguide to microstrip transition design

    NASA Technical Reports Server (NTRS)

    Ponchak, George E.; Downey, Alan N.

    1986-01-01

    A new model is presented which permits the prediction of the resonant frequencies created by antipodal finline waveguide to microstrip transitions. The transition is modeled as a tapered transmission line in series with an infinite set of coupled resonant circuits. The resonant circuits are modeled as simple microwave resonant cavities of which the resonant frequencies are easily determined. The model is developed and the resonant frequencies determined for several different transitions. Experimental results are given to confirm the models.

  11. A switchable microstrip antenna

    NASA Astrophysics Data System (ADS)

    Khitrov, Iu. A.

    1992-03-01

    A switchable microstrip antenna is proposed which maintains nondirected radiation in the horizontal plane for all combinations of states of the switched elements. Theoretical and experimental results of studies of the directivity characteristics are presented.

  12. Resonant excitation of black holes by massive bosonic fields and giant ringings

    NASA Astrophysics Data System (ADS)

    Décanini, Yves; Folacci, Antoine; Ould El Hadj, Mohamed

    2014-04-01

    We consider the massive scalar field, the Proca field, and the Fierz-Pauli field in the Schwarzschild spacetime and we focus more particularly on their long-lived quasinormal modes. We show numerically that the associated excitation factors have a strong resonant behavior and we confirm this result analytically from semiclassical considerations based on the properties of the unstable circular geodesics on which a massive particle can orbit the black hole. The conspiracy of (i) the long-lived behavior of the quasinormal modes and (ii) the resonant behavior of their excitation factors induces intrinsic giant ringings, i.e., ringings of a huge amplitude. Such ringings, which are moreover slowly decaying, are directly constructed from the retarded Green function. If we describe the source of the black hole perturbation by an initial value problem with Gaussian initial data, i.e., if we consider the excitation of the black hole from an extrinsic point of view, we can show that these extraordinary ringings are still present. This suggests that physically realistic sources of perturbations should generate giant and slowly decaying ringings and that their existence could be used to constrain ultralight bosonic field theory interacting with black holes.

  13. Stochastic charging of dust grains in planetary rings: Diffusion rates and their effects on Lorentz resonances

    NASA Technical Reports Server (NTRS)

    Schaffer, L.; Burns, J. A.

    1995-01-01

    Dust grains in planetary rings acquire stochastically fluctuating electric charges as they orbit through any corotating magnetospheric plasma. Here we investigate the nature of this stochastic charging and calculate its effect on the Lorentz resonance (LR). First we model grain charging as a Markov process, where the transition probabilities are identified as the ensemble-averaged charging fluxes due to plasma pickup and photoemission. We determine the distribution function P(t;N), giving the probability that a grain has N excess charges at time t. The autocorrelation function tau(sub q) for the strochastic charge process can be approximated by a Fokker-Planck treatment of the evolution equations for P(t; N). We calculate the mean square response to the stochastic fluctuations in the Lorentz force. We find that transport in phase space is very small compared to the resonant increase in amplitudes due to the mean charge, over the timescale that the oscillator is resonantly pumped up. Therefore the stochastic charge variations cannot break the resonant interaction; locally, the Lorentz resonance is a robust mechanism for the shaping of etheral dust ring systems. Slightly stronger bounds on plasma parameters are required when we consider the longer transit times between Lorentz resonances.

  14. Artificial permeability and antibonding magnetic resonance in a copper-structured metamaterial with symmetry-broken ring-plate resonators.

    PubMed

    Wang, Y K; Dong, Z G; Zhai, Y

    2012-08-01

    We numerically investigate the antibonding magnetic resonance in a metamaterial composed of rings and plates, with a particular attention to the influence of broken structural symmetry on the Fano-type transmission spectrum as well as the resonant artificial permeability. From the simulation results, it is obvious that the antibonding magnetic resonance with strong magnetic-dipole coupling is responsible for the Fano-type profile, since an increase of the structural asymmetry extent to reduce the magnetic field confinement in one of the gaps will form, in contrary, a Lorentzian resonance dip. The dual excitation pathways, i.e., electric and magnetic resonances, at destructive interference are the underlying reason of the Fano-type transmission response. Additionally, the structural-asymmetry dependence of the artificial permeability shows that the broken symmetry can strongly modify the effective permeability due to the altering magnetic-dipole interactions. It is found that an anti-resonant curve of permeability versus frequency will be resulted in if significant symmetry-broken structure is introduced.

  15. Plasmonic devices based on the dual coupled graphene-integrated ring resonators

    NASA Astrophysics Data System (ADS)

    Wang, Jicheng; Xia, Xiushan; Liang, Xiuye; Chen, Jing; Liu, Dongdong

    2015-08-01

    We have proposed a couple of plasmonic devices based on graphene sheets and ring resonators. The highly frequency-tunable multi-mode plasmonically induced transparency (PIT) device based on monolayer graphene and rings for the mid-IR region is presented in theory firstly. The multi-mode transparency windows in the spectral responses and slow light effects can be achieved in plasmonic configuration composed of two graphene resonators coupled with single-layer graphene waveguide. By varying the Fermi energy of the graphene, the multi-mode PIT resonance can be dynamic controlled without reoptimizing the geometric parameters of the structures. Based on the coupled mode theory (CMT) and Fabry-Perot (FP), we numerically investigated direct coupling and indirect coupling in the graphene-integrated PIT systems. In addition, the theoretical plasmonic devices based on graphene sheets and ring resonators are also proposed to perform as 1×2 optical spatial switch or ultra -compact Mach-Zehnder interferometer. The finite element method (FEM) is carried on to verify our designs. Those designs may pave the ways for the further development of the compact high-performance plasmonic communication devices.

  16. A universal label-free biosensing platform based on opto-fluidic ring resonators

    NASA Astrophysics Data System (ADS)

    Zhu, Hongying; White, Ian M.; Suter, Jonathan D.; Gohring, John; Fan, Xudong

    2009-02-01

    Rapid and accurate detection of biomolecules is important for medical diagnosis, pharmaceuticals, homeland security, food quality control, and environmental protection. A simple, low cost and highly sensitive label-free optical biosensor based on opto-fluidic ring resonator (OFRR) has been developed that naturally integrates microfluidics with ring resonators. The OFRR employs a piece of fused silica capillary with a diameter around 100 micrometers. The circular cross section of the capillary forms the ring resonator and light repeatedly travels along the resonator circumference in the form of whispering gallery modes (WGMs) through total internal reflection. When the capillary wall is as thin as a couple of micrometers (< 4 μm), an evanescent field of the WGMs exists at the OFRR inner surface and interacts with the sample when it flows through the OFRR. In order to detect the target molecules with high specificity, the OFRR inner surface is functionalized with receptors, such as antibodies, peptide-displayed bacteriophage or oligonucleotide DNA probes. The WGM spectral position shifts when biomolecules bind to the OFRR inner surface and change the local refractive index, which provides quantitative and kinetic information about the biomolecule interaction near the OFRR inner surface. The OFRR has been successfully demonstrated for detection of various types of biomoelcuels. Here, we will first introduce the basic operation principle of the OFRR as a sensor and then application examples of the OFRR in the detection of proteins, disease biomarkers, virus, DNA molecules, and cells with high sensitivities will be presented.

  17. Real-time label-free biosensing with integrated planar waveguide ring resonators

    NASA Astrophysics Data System (ADS)

    Sohlström, Hans; Gylfason, Kristinn B.; Hill, Daniel

    2010-05-01

    We review the use of planar integrated optical waveguide ring resonators for label free bio-sensing and present recent results from two European biosensor collaborations: SABIO and InTopSens. Planar waveguide ring resonators are attractive for label-free biosensing due to their small footprint, high Q-factors, and compatibility with on-chip optics and microfluidics. This enables integrated sensor arrays for compact labs-on-chip. One application of label-free sensor arrays is for point-of-care medical diagnostics. Bringing such powerful tools to the single medical practitioner is an important step towards personalized medicine, but requires addressing a number of issues: improving limit of detection, managing the influence of temperature, parallelization of the measurement for higher throughput and on-chip referencing, efficient light-coupling strategies to simplify alignment, and packaging of the optical chip and integration with microfluidics. From the SABIO project we report refractive index measurement and label-free biosensing in an 8-channel slotwaveguide ring resonator sensor array, within a compact cartridge with integrated microfluidics. The sensors show a volume sensing detection limit of 5 x 10-6 RIU and a surface sensing detection limit of 0.9 pg/mm2. From the InTopSens project we report early results on silicon-on-insulator racetrack resonators.

  18. Tunable THz wave absorption by graphene-assisted plasmonic metasurfaces based on metallic split ring resonators

    NASA Astrophysics Data System (ADS)

    Ahmadivand, Arash; Sinha, Raju; Karabiyik, Mustafa; Vabbina, Phani Kiran; Gerislioglu, Burak; Kaya, Serkan; Pala, Nezih

    2017-01-01

    Graphene plasmonics has been introduced as a novel platform to design various nano- and microstructures to function in a wide range of spectrum from optical to THz frequencies. Herein, we propose a tunable plasmonic metamaterial in the THz regime by using metallic (silver) concentric microscale split ring resonator arrays on a multilayer metasurface composed of silica and silicon layers. We obtained an absorption percentage of 47.9% including two strong Fano resonant dips in THz regime for the purely plasmonic metamaterial without graphene layer. Considering the data of an atomic graphene sheet (with the thickness of 0.35 nm) in both analytical and experimental regimes obtained by prior works, we employed a graphene layer under concentric split ring resonator arrays and above the multilayer metasurface to enhance the absorption ratio in THz bandwidth. Our numerical and analytical results proved that the presence of a thin graphene layer enhances the absorption coefficient of MM to 64.35%, at the highest peak in absorption profile that corresponds to the Fano dip position. We also have shown that changing the intrinsic characteristics of graphene sheet leads to shifts in the position of Fano dips and variations in the absorption efficiency. The maximum percentage of absorption ( 67%) was obtained for graphene-based MM with graphene layer with dissipative loss factor of 1477 Ω. Employing the antisymmetric feature of the split ring resonators, the proposed graphene-based metamaterial with strong polarization dependency is highly sensitive to the polarization angle of the incident THz beam.

  19. Transmission performance of one waveguide and double micro-ring resonator using 3×3 optical fiber coupler

    NASA Astrophysics Data System (ADS)

    Zhao, Chao Ying; Tan, Wei Han

    2016-09-01

    This paper investigates theoretically the transmission characteristics of one waveguide and double micro-ring resonator using 3 × 3 optical fibre coupler. Our analytical solution of transmittance is suitable for either linearly distributed coupler or circularly symmetric distributed coupler. The all-optical analogue to electromagnetic inducted transparency spectrum of one waveguide and double micro-ring resonators can be controlled by changing the coupling strength between waveguide and micro-rings, the absorption coefficient around micro-rings, as well as the asymmetric coupling coefficients between non-adjacent waveguides. The curves show that the transitions of transmission spectra sensitively depend on asymmetric coupling coefficients.

  20. Thermo-optically tunable switching in an electro-microtube ring resonator

    NASA Astrophysics Data System (ADS)

    Zeng, Jing; Zhu, Tao; Deng, Ming

    2015-07-01

    We propose a tunable optical switching based on thermo-optic nonlinear effect in an electro-microtube ring resonator (EMRR) made by a capillary embedded with a heating wire. The significant modes shift in the EMRR for nonlinear switching are attributed to a huge joule heat generated by the heating wire, leading to the resonant wavelength shifts over 0.9nm when using 250mA current. In our viewpoints, with such a significant performance, the EMRR may be practically applied to switching, optical filter, sensing and optical network process.

  1. Series-coupled double-ring resonators with asymmetric radii for use in channelizer

    NASA Astrophysics Data System (ADS)

    Gu, Xiaowen; Zhu, Dan; Zhao, Yongjiu; Pan, Shilong

    2014-10-01

    A series-coupled double-ring resonator with asymmetric radii is analyzed to achieve a filter response with a large free spectral range (FSR), a narrow passband of tens of MHz and a small shape factor simultaneously for use in microwave photonic channelizer. By introducing difference to the two radii, based on the vernier effect, the FSR of the resonator filter can be extended while maintaining the narrow passband and the small shape factor. A filter response with a FSR of 29.444 GHz, a 3-dB bandwidth of 96 MHz and a shape factor of 3.17 is realized by numerical analysis.

  2. Magneto-optic transmittance modulation observed in a hybrid graphene–split ring resonator terahertz metasurface

    SciTech Connect

    Zanotto, Simone; Pitanti, Alessandro; Lange, Christoph; Maag, Thomas; Huber, Rupert; Miseikis, Vaidotas; Coletti, Camilla; Degl'Innocenti, Riccardo; Baldacci, Lorenzo; Tredicucci, Alessandro

    2015-09-21

    By placing a material in close vicinity of a resonant optical element, its intrinsic optical response can be tuned, possibly to a wide extent. Here, we show that a graphene monolayer, spaced a few tenths of nanometers from a split ring resonator metasurface, exhibits a magneto-optical response which is strongly influenced by the presence of the metasurface itself. This hybrid system holds promises in view of thin optical modulators, polarization rotators, and nonreciprocal devices, in the technologically relevant terahertz spectral range. Moreover, it could be chosen as the playground for investigating the cavity electrodynamics of Dirac fermions in the quantum regime.

  3. Angular-resolved electron energy loss spectroscopy on a split-ring resonator

    NASA Astrophysics Data System (ADS)

    von Cube, F.; Niegemann, J.; Irsen, S.; Bell, D. C.; Linden, S.

    2014-03-01

    We investigate the plasmonic near field of a lithographically defined split-ring resonator with angular-resolved electron energy loss spectroscopy in a scanning transmission electron microscope. By tilting the sample, different electric field components of the plasmonic modes can be probed with the electron beam. The electron energy loss spectra recorded under oblique incidence can feature plasmonic resonances that are not observable under normal incidence. Our experimental findings are supported by full numerical calculations based on the discontinuous Galerkin time-domain method.

  4. Lorentz resonances and the vertical structure of dusty rings - Analytical and numerical results

    NASA Astrophysics Data System (ADS)

    Schaffer, Les; Burns, Joseph A.

    1992-03-01

    The Schaffer and Burns (1987) linear theory of Lorentz resonances (LRs) in planetary rings is extended in order to accurately compute LR locations and to elucidate the nature of grain trajectories within the LR zones. Using the perturbation theory and energy arguments, it is shown that an increase in the inclination or eccentricity of a grain must be accompanied by a shift in the mean orbital radius of the particle. This shift alters the epicyclic frequencies in such a way that the infinite response of the linear resonance theory is suppressed. Chaotic motion is found for the range of charge-to-mass ratios that cause the vertical and horizontal LRs to overlap.

  5. Fault diagnosis for wind turbine planetary ring gear via a meshing resonance based filtering algorithm.

    PubMed

    Wang, Tianyang; Chu, Fulei; Han, Qinkai

    2017-03-01

    Identifying the differences between the spectra or envelope spectra of a faulty signal and a healthy baseline signal is an efficient planetary gearbox local fault detection strategy. However, causes other than local faults can also generate the characteristic frequency of a ring gear fault; this may further affect the detection of a local fault. To address this issue, a new filtering algorithm based on the meshing resonance phenomenon is proposed. In detail, the raw signal is first decomposed into different frequency bands and levels. Then, a new meshing index and an MRgram are constructed to determine which bands belong to the meshing resonance frequency band. Furthermore, an optimal filter band is selected from this MRgram. Finally, the ring gear fault can be detected according to the envelope spectrum of the band-pass filtering result.

  6. New design of a triplexer using ring resonator integrated with directional coupler based on photonic crystals

    NASA Astrophysics Data System (ADS)

    Wu, Yaw-Dong; Shih, Tien-Tsorng; Lee, Jian-Jang

    2009-11-01

    In this paper, we proposed the design of directional coupler integrated with ring resonator based on two-dimensional photonic crystals (2D PCs) to develop a triplexer filter. It can be widely used as the fiber access network element for multiplexer-demultiplexer wavelength selective in fiber-to-the-home (FTTH) communication systems. The directional coupler is chosen to separate the wavelengths of 1490nm and 1310nm. The ring resonator separates the wavelength of 1550nm. The transmission efficiency is larger than 90%. Besides, the total size of propose triplexer is only 19μm×12μm. We present simulation results using the finite-difference time-domain (FDTD) method for the proposed structure.

  7. Highly sensitive detection of glucose concentration with opto-fluidics ring resonator

    NASA Astrophysics Data System (ADS)

    Luo, Yunhan; Khaing Oo, Maung Kyaw; Ge, Jia; Chen, Zhe; Fan, Xudong

    2012-06-01

    Noninvasive detection of glucose has been heavily researched in their roles of offering cost-effective, painless, and bloodless monitoring of glucose concentration. In this work, we describe a novel, label-free, and sensitive approach for detecting the glucose concentration in human interstitial fluid samples using the opto-fluidic ring resonator (OFRR). The OFRR incorporates microfluidics and optical ring resonator sensing technology to achieve rapid label-free detection in a small and low-cost platform. In this study, bulk refractive index measurements are presented. Results show that the OFRR is able to detect glucose at medically relevant concentrations in interstitial fluid ranging from 0 to 25 mM, with a detection limit of 0.32 mM, which is lower than clinical requirement by one order of magnitude. Our work is believed to lead to a device that can be used to frequently monitor glucose concentration in a low-cost and painless manner.

  8. Novel ultrasound detector based on small slot micro-ring resonator with ultrahigh Q factor

    NASA Astrophysics Data System (ADS)

    Zhang, Senlin; Chen, Jian; He, Sailing

    2017-01-01

    An ultrasound detector based on a novel slot micro-ring resonator (SMRR) with ultrahigh Q factor and small size is proposed in this study. The theoretical Q factor of SMRR can be approximately 8.34×108 with bending radius of merely 12 μm. The ultrahigh Q factor leads to an enhanced sensitivity that is approximately two orders of that of state-of-the-art ultrasound detector based on polymer micro-ring resonator. Moreover, the 3 dB bandwidth of the ultrasound detector is approximately 540 MHz, thereby leading to an ultrahigh axial resolution of 1.2 μm. The proposed detector is also CMOS compatible and can be easily and extensively integrated to be maximized in photoacoustic microscopy.

  9. Self-generation of dissipative solitons in magnonic quasicrystal active ring resonator

    NASA Astrophysics Data System (ADS)

    Grishin, S. V.; Beginin, E. N.; Morozova, M. A.; Sharaevskii, Yu. P.; Nikitov, S. A.

    2014-02-01

    Self-generation of dissipative solitons in the magnonic quasicrystal (MQC) active ring resonator is studied theoretically and experimentally. The developed magnonic crystal has quasiperiodic Fibonacci type structure. Frequency selectivity of the MQC together with the parametric three-wave decay of magnetostatic surface spin wave (MSSW) leads to the dissipative soliton self-generation. The transfer matrix method is used to describe MQC transmission responses. Besides, the model of MQC active ring resonator is suggested. The model includes three coupled differential equations describing the parametric decay of MSSW and two differential equations of linear oscillators describing the frequency selectivity of MQC. Numerical simulation results of dissipative soliton self-generation are in a fair agreement with experimental data.

  10. Self-generation of dissipative solitons in magnonic quasicrystal active ring resonator

    SciTech Connect

    Grishin, S. V. Beginin, E. N.; Morozova, M. A.; Sharaevskii, Yu. P.; Nikitov, S. A.

    2014-02-07

    Self-generation of dissipative solitons in the magnonic quasicrystal (MQC) active ring resonator is studied theoretically and experimentally. The developed magnonic crystal has quasiperiodic Fibonacci type structure. Frequency selectivity of the MQC together with the parametric three-wave decay of magnetostatic surface spin wave (MSSW) leads to the dissipative soliton self-generation. The transfer matrix method is used to describe MQC transmission responses. Besides, the model of MQC active ring resonator is suggested. The model includes three coupled differential equations describing the parametric decay of MSSW and two differential equations of linear oscillators describing the frequency selectivity of MQC. Numerical simulation results of dissipative soliton self-generation are in a fair agreement with experimental data.

  11. Molecular buffer using a PANDA ring resonator for drug delivery use.

    PubMed

    Suwanpayak, N; Jalil, M A; Aziz, M S; Ali, J; Yupapin, P P

    2011-01-01

    A novel design of molecular buffer for molecule storage and delivery using a PANDA ring resonator is proposed. The optical vortices can be generated and controlled to form the trapping tools in the same way as the optical tweezers. In theory, the trapping force is formed by the combination between the gradient field and scattering photons, which is reviewed. By using the intense optical vortices generated within the PANDA ring resonator, the required molecules can be trapped and moved (transported) dynamically within the wavelength router or network, ie, a molecular buffer. This can be performed within the wavelength router before reaching the required destination. The advantage of the proposed system is that a transmitter and receiver can be formed within the same system, which is available for molecule storage and transportation.

  12. Tissue culture system using a PANDA ring resonator and wavelength router for hydroponic plant.

    PubMed

    Kamoldilok, Surachart; Suwanpayak, Nathaporn; Suttirak, Saisudawan; Yupapin, Preecha P

    2012-06-01

    A novel system of nanofluidics trapping and delivery, which is known as a tissue culture system is proposed. By using the intense optical pulse(i.e., a soliton pulse) and a system constructed by a liquid core waveguide, the optical vortices (gradient optical fields/wells) can be generated, where the trapping tools in the same way as the optical tweezers in the PANDA ring resonator can be formed. By controlling the suitable parameters, the intense optical vortices can be generated within the PANDA ring resonator, in which the nanofluidics can be trapped and moved (transported) dynamically within the Tissue culture system(a wavelength router), which can be used for tissue culture and delivery in the hydroponic plant system.

  13. Topological phononic states of underwater sound based on coupled ring resonators

    SciTech Connect

    He, Cheng; Li, Zheng; Ni, Xu; Sun, Xiao-Chen; Yu, Si-Yuan; Lu, Ming-Hui Liu, Xiao-Ping; Chen, Yan-Feng

    2016-01-18

    We report a design of topological phononic states for underwater sound using arrays of acoustic coupled ring resonators. In each individual ring resonator, two degenerate acoustic modes, corresponding to clockwise and counter-clockwise propagation, are treated as opposite pseudospins. The gapless edge states arise in the bandgap resulting in protected pseudospin-dependent sound transportation, which is a phononic analogue of the quantum spin Hall effect. We also investigate the robustness of the topological sound state, suggesting that the observed pseudospin-dependent sound transportation remains unless the introduced defects facilitate coupling between the clockwise and counter-clockwise modes (in other words, the original mode degeneracy is broken). The topological engineering of sound transportation will certainly promise unique design for next generation of acoustic devices in sound guiding and switching, especially for underwater acoustic devices.

  14. Tunable Plasmonic Band-Pass Filter with Dual Side-Coupled Circular Ring Resonators

    PubMed Central

    Liu, Dongdong; Wang, Jicheng; Zhang, Feng; Pan, Yuewu; Lu, Jian; Ni, Xiaowu

    2017-01-01

    A wavelength band-pass filter with asymmetric dual circular ring resonators in a metal-insulator-metal (MIM) structure is proposed and numerically simulated. For the interaction of the local discrete state and the continuous spectrum caused by the side-coupled resonators and the baffle, respectively, the transmission spectrum exhibits a sharp and asymmetric profile. By adjusting the radius and material imbedded in one ring cavity, the off-to-on plasmon-induced absorption (PIA) optical response can be tunable achieved. In addition, the structure can be easily extended to other similar compact structures to realize the filtering task. Our structures have important potential applications for filters and sensors at visible and near-infrared regions. PMID:28335398

  15. High quality factor trapezoidal subwavelength grating waveguide micro-ring resonator

    NASA Astrophysics Data System (ADS)

    Wang, Zheng; Xu, Xiaochuan; Fan, D. L.; Wang, Yaguo; Chen, Ray T.

    2016-03-01

    In recent decades, silicon photonics has attracted intensive research interest in optical communications due to its advantageous compact dimensions and high-volume manufacturability. Particularly, micro-ring resonators on silicon-oninsulator (SOI) platform have been widely exploited as a basic building block for a vast range of applications such as switches, modulators, and sensors. A majority of these applications involve light-matter interaction, which can be substantially enhanced by the high quality factor micro-ring resonators. However, conventional strip waveguide based micro-ring resonators suffer from the intrinsic dilemma in achieving high light confinement and strong light-matter interaction simultaneously. Subwavelength grating (SWG) waveguides, comprised of periodically interleaved high and low refractive index materials with a pitch less than one wavelength, have been demonstrated as a promising alternative. For SWG waveguides built on SOI wafers, the ratio of silicon and cladding materials can be engineered microscopically to achieve desired macroscopic properties. The control of these properties could potentially lead to significant performance improvements compared with conventional micro-ring resonators based photonic devices, such as filters and sensors. However, SWG waveguide based micro-ring resonators (SWGMRs) that have been demonstrated so far can only provide a moderate quality factor (~5600) with a large radius (e.g. 15 μm), which greatly jeopardize the wide spread research efforts in this area. In this paper, we propose to use trapezoidal silicon pillars to reduce the bend loss of SWGMRs to improve the quality factor. For the first time, we experimentally demonstrate the smallest SWGMR (the micro-ring radius equals to 5 μm) with an applicable quality factor as high as 11,500. This approach also can be applied to SWGMRs with larger radii for higher quality factors. We also experimentally demonstrated a 10 μm radius SWGMR that can provide

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

    PubMed Central

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

    2016-01-01

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

  17. Optimization of optical filter using triple coupler ring resonators structure based on polyimide substrate

    NASA Astrophysics Data System (ADS)

    Mahmudin, D.; Estu, T. T.; Fathnan, A. A.; Maulana, Y. Y.; Daud, P.; Sugandhi, G.; Wijayanto, Y. N.

    2016-11-01

    Optical filter is very important components in WDM network. MRR is a basic structure to design the optical filter because of easy to design for improving its performance. This paper discusses an innovative structure of the MRR, which is Triple Coupler Ring Resonators (TCRR) for optical filter applications. Values of width between bus and ring and values of radius of the ring in the structure TCRR were analyzed and optimized for several variations for obtaining coupling coefficient values. Therefore, wide Free Spectral Range (FSR) and high crosstalk suppression bandwidth can be obtained. As results, at the optimized width of gap of 100 nm and the optimized radiation of 8 μm, FSR of 2.85 THz and crosstalk suppression bandwidth of 60 GHz were achieved. Based on the results, this structure can be used for filtering optical signals in optical fiber communication.

  18. Stable and wavelength-tunable silicon-micro-ring-resonator based erbium-doped fiber laser.

    PubMed

    Yang, L G; Yeh, C H; Wong, C Y; Chow, C W; Tseng, F G; Tsang, H K

    2013-02-11

    In this work, we propose and demonstrate a stable and wavelength-tunable erbium-doped fiber (EDF) ring laser. Here, a silicon-on-insulator (SOI)-based silicon-micro-ring-resonator (SMRR) is used as the wavelength selective element inside the fiber ring cavity. A uniform period grating coupler (GC) is used to couple between the SMRR and single mode fiber (SMF) and serves also as a polarization dependent element in the cavity. The output lasing wavelength of the proposed fiber laser can be tuned at a tuning step of 2 nm (defined by the free spectral range (FSR) of the SMRR) in a bandwidth of 35.2 nm (1532.00 to 1567.20 nm), which is defined by the gain of the EDF. The optical-signal-to-noise-ratio (OSNR) of each lasing wavelength is larger than 42.0 dB. In addition, the output stabilities of power and wavelength are also discussed.

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

    NASA Astrophysics Data System (ADS)

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

    2016-12-01

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

  20. Photoacoustic probe using a micro-ring resonator ultrasonic sensor for endoscopic applications

    PubMed Central

    Dong, Biqin; Chen, Siyu; Zhang, Zhen; Sun, Cheng; Zhang, Hao F.

    2015-01-01

    We designed an all-optical photoacoustic probe for endoscopic applications by employing an optically-transparent, coverslip-type, polymeric micro-ring resonator ultrasonic sensor. We experimentally quantified the axial, tangential, and radial resolutions and angular sensitive stability of this probe. Using this probe, we achieved volumetric imaging of several phantoms. Our all-optical probe design offers clear benefit in integrating photoacoustic endoscope with other optical endoscopic imaging modalities to facilitate the transformation from bench to bedside. PMID:25078180

  1. Dispersion engineering of thick high-Q silicon nitride ring-resonators via atomic layer deposition.

    PubMed

    Riemensberger, Johann; Hartinger, Klaus; Herr, Tobias; Brasch, Victor; Holzwarth, Ronald; Kippenberg, Tobias J

    2012-12-03

    We demonstrate dispersion engineering of integrated silicon nitride based ring resonators through conformal coating with hafnium dioxide deposited on top of the structures via atomic layer deposition. Both, magnitude and bandwidth of anomalous dispersion can be significantly increased. The results are confirmed by high resolution frequency-comb-assisted-diode-laser spectroscopy and are in very good agreement with the simulated modification of the mode spectrum.

  2. Dissipative soliton generation in an active ring resonator based on magnonic quasicrystal with Fibonacci type structure

    NASA Astrophysics Data System (ADS)

    Grishin, S. V.; Beginin, E. N.; Sharaevskii, Yu. P.; Nikitov, S. A.

    2013-07-01

    This study reports on the experimental investigations of a magnetostatic surface wave (MSSW) propagation in a magnonic quasicrystal (MQC) with Fibonacci type structure. It is shown that such structure has a greater number of band gaps and narrower pass bands located between them than a periodic structure. These features of the MQC and three-wave decay of the MSSW are used in a MQC active ring resonator for the eigenmode selection and dissipative soliton self-generation.

  3. Near-field coupling and second-harmonic generation in split-ring resonator arrays

    NASA Astrophysics Data System (ADS)

    Grynko, Yevgen; Meier, Torsten; Linden, Stefan; Niesler, Fabian B. P.; Wegener, Martin; Förstner, Jens

    2012-09-01

    We simulate the linear and nonlinear optical response from split-ring resonator (SRR) arrays to study collective effects between the constituent SRRs that determine spectral properties of the second harmonic generation (SHG). We apply the Discontinuous Galerkin Time Domain (DGTD) method and the hydrodynamic Maxwell-Vlasov model to calculate the SHG emission. Our model is able to qualitatively reproduce and explain the non-monotonic dependence of the spectral SHG transmission measured experimentally for SRR arrays with different lattice constants [1].

  4. A Weakly Nonlinear Model for the Damping of Resonantly Forced Density Waves in Dense Planetary Rings

    NASA Astrophysics Data System (ADS)

    Lehmann, Marius; Schmidt, Jürgen; Salo, Heikki

    2016-10-01

    In this paper, we address the stability of resonantly forced density waves in dense planetary rings. Goldreich & Tremaine have already argued that density waves might be unstable, depending on the relationship between the ring’s viscosity and the surface mass density. In the recent paper Schmidt et al., we have pointed out that when—within a fluid description of the ring dynamics—the criterion for viscous overstability is satisfied, forced spiral density waves become unstable as well. In this case, linear theory fails to describe the damping, but nonlinearity of the underlying equations guarantees a finite amplitude and eventually a damping of the wave. We apply the multiple scale formalism to derive a weakly nonlinear damping relation from a hydrodynamical model. This relation describes the resonant excitation and nonlinear viscous damping of spiral density waves in a vertically integrated fluid disk with density dependent transport coefficients. The model consistently predicts density waves to be (linearly) unstable in a ring region where the conditions for viscous overstability are met. Sufficiently far away from the Lindblad resonance, the surface mass density perturbation is predicted to saturate to a constant value due to nonlinear viscous damping. The wave’s damping lengths of the model depend on certain input parameters, such as the distance to the threshold for viscous overstability in parameter space and the ground state surface mass density.

  5. On-column micro gas chromatography detection with capillary-based optical ring resonators.

    PubMed

    Shopova, Siyka I; White, Ian M; Sun, Yuze; Zhu, Hongying; Fan, Xudong; Frye-Mason, Greg; Thompson, Aaron; Ja, Shiou-jyh

    2008-03-15

    We developed a novel on-column micro gas chromatography (microGC) detector using capillary based optical ring resonators (CBORRs). The CBORR is a thin-walled fused silica capillary with an inner diameter ranging from a few tens to a few hundreds of micrometers. The interior surface of the CBORR is coated with a layer of stationary phase for gas separation. The circular cross section of the CBORR forms a ring resonator and supports whispering gallery modes (WGMs) that circulate along the ring resonator circumference hundreds of times. The evanescent field extends into the core and is sensitive to the refractive index change induced by the interaction between the gas sample and the stationary phase. The WGM can be excited and monitored at any location along the CBORR by placing a tapered optical fiber against the CBORR, thus enabling on-column real-time detection. Rapid separation of both polar and nonpolar samples was demonstrated with subsecond detection speed. Theoretical work was also established to explain the CBORR detection mechanism. While low-nanogram detection limits are observed in these preliminary tests, many methods for improvements are under investigation. The CBORR is directly compatible with traditional capillary GC columns without any dead volumes. Therefore, the CBORR-based muGC is a very promising technology platform for rapid, sensitive, and portable analytical devices.

  6. Quantum nonlinear resonance and quantum chaos in Aharonov-Bohm oscillations in mesoscopic semiconductor rings

    SciTech Connect

    Berman, G.P.; Bulgakov, E.N.; Campbell, D.K.; Krive, I.V.

    1997-10-01

    We consider Aharonov-Bohm oscillations in a mesoscopic semiconductor ring threaded by both a constant magnetic flux and a time-dependent, resonant magnetic field with one or two frequencies. Working in the ballistic regime, we establish that the theory of {open_quotes}quantum nonlinear resonance{close_quotes} applies, and thus that this system represents a possible solid-state realization of {open_quotes}quantum nonlinear resonance{close_quotes} and {open_quotes}quantum chaos.{close_quotes} In particular, we investigate the behavior of the time-averaged electron energy at zero temperature in the regimes of (i) an isolated quantum nonlinear resonance and (ii) the transition to quantum chaos, when two quantum nonlinear resonances overlap. The time-averaged energy exhibits sharp resonant behavior as a function of the applied constant magnetic flux, and has a staircase dependence on the amplitude of the external time-dependent field. In the chaotic regime, the resonant behavior exhibits complex structure as a function of flux and frequency. We compare and contrast the quantum chaos expected in these mesoscopic {open_quotes}solid-state atoms{close_quotes} with that observed in Rydberg atoms in microwave fields, and discuss the prospects for experimental observation of the effects we predict. {copyright} {ital 1997} {ital The American Physical Society}

  7. Air-mode photonic crystal ring resonator on silicon-on-insulator

    PubMed Central

    Gao, Ge; Zhang, Yong; Zhang, He; Wang, Yi; Huang, Qingzhong; Xia, Jinsong

    2016-01-01

    In this report, we propose and demonstrate an air-mode photonic crystal ring resonator (PhCRR) on silicon-on-insulator platform. Air mode is utilized to confine the optical field into photonic crystal (PhC) air holes, which is confirmed by the three-dimensional finite-difference time-domain simulation. PhCRR structure is employed to enhance the light-matter interaction through combining the whispering-gallery mode resonance of ring resonator with the slow-light effect in PhC waveguide. In the simulated and measured transmission spectra of air-mode PhCRR, nonuniform free spectral ranges are observed near the Brillouin zone edge of PhC, indicating the presence of the slow-light effect. A maximum group index of 27.3 and a highest quality factor of 14600 are experimentally obtained near the band edge. Benefiting from the strong optical confinement in the PhC holes and enhanced light-matter interaction in the resonator, the demonstrated air-mode PhCRR is expected to have potential applications in refractive index sensing, on-chip light emitting and nonlinear optics by integration with functional materials. PMID:26818430

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

    PubMed Central

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

    2016-01-01

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

  9. Extraordinary terahertz transmission through a double-layer metal array with closed ring resonators

    NASA Astrophysics Data System (ADS)

    Guo, Yadong; Yuan, Zongheng; Yuan, Yuyang; Wang, Sheng; Zhang, Wentao

    2016-07-01

    In this paper, we numerically investigate the transmission properties of a terahertz metamaterial. This metamaterial is composed of metal-dielectric-metal, which consists of metallic layers with an air hole array and one coaxial closed ring resonator in the air hole. The metamaterial in the THz range of 0.2-1 THz has three transmission peaks. We provide an explanation of the transmission peaks by means of the surface plasmon polaritons and magnetic polaritons resonance based on the distribution of the surface current. Then according to the magnetic polaritons resonance, the equivalent circuit model of the metamaterial is established. The effects of geometric parameters on the transmission peaks are discussed and studied by an equivalent circuit model and surface plasmon polaritons dispersion relation. Our metamaterial promises dual-band potential applications such as filters.

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

    NASA Astrophysics Data System (ADS)

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

    2016-02-01

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

  11. Time-domain measurement of optical transport in silicon micro-ring resonators.

    PubMed

    Pernice, Wolfram H P; Li, Mo; Tang, Hong X

    2010-08-16

    We perform time-domain measurements of optical transport dynamics in silicon nano-photonic devices. Using pulsed optical excitation the thermal and carrier induced optical nonlinearities of micro-ring resonators are investigated, allowing for identification of their individual contributions. Under pulsed excitation build-up of free carriers and heat in the waveguides leads to a beating oscillation of the cavity resonance frequency. When employing a burst of pulse trains shorter than the carrier life-time, the slower heating effect can be separated from the faster carrier effect. Our scheme provides a convenient way to thermally stabilize optical resonators for high-power time-domain applications and nonlinear optical conversion.

  12. Narrow band wavelength selective filter using grating assisted single ring resonator

    SciTech Connect

    Prabhathan, P. Murukeshan, V. M.

    2014-09-15

    This paper illustrates a filter configuration which uses a single ring resonator of larger radius connected to a grating resonator at its drop port to achieve single wavelength selectivity and switching property with spectral features suitable for on-chip wavelength selection applications. The proposed configuration is expected to find applications in silicon photonics devices such as, on-chip external cavity lasers and multi analytic label-free biosensors. The grating resonator has been designed for a high Q-factor, high transmittivity, and minimum loss so that the wavelength selectivity of the device is improved. The proof-of-concept device has been demonstrated on a Silicon-on-Insulator (SOI) platform through electron beam lithography and Reactive Ion Etching (RIE) process. The transmission spectrum shows narrow band single wavelength selection and switching property with a high Free Spectral Range (FSR) ∼60 nm and side band rejection ratio >15 dB.

  13. Design and characterization of a novel toroidal split-ring resonator

    SciTech Connect

    Bobowski, J. S. Nakahara, Hiroko

    2016-02-15

    The design and characterization of a novel toroidal split-ring resonator (SRR) are described in detail. In conventional cylindrical SRRs, there is a large magnetic flux within the bore of the resonator. However, there also exists a non-negligible magnetic flux in the free space surrounding the resonator. The energy losses associated with this radiated power diminish the resonator’s quality factor. In the toroidal SRR, on the other hand, the magnetic field lines are strongly confined within the bore of the resonator resulting in high intrinsic quality factors and stable resonance frequencies without requiring additional electromagnetic shielding. This paper describes the design and construction of a toroidal SRR as well as an experimental investigation of its cw response in the frequency-domain and its time-domain response to a rf pulse. Additionally, the dependence of the toroidal SRR’s resonant frequency and quality factor on the strength of inductive coupling to external circuits is investigated both theoretically and experimentally.

  14. The microstrip proportional counter

    NASA Technical Reports Server (NTRS)

    Ramsey, B. D.

    1992-01-01

    Microstrip detectors in which the usual discrete anode and cathode wires are replaced by conducting strips on an insulating or partially insulating substrate are fabricated using integrated circuit-type photolithographic techniques and hence offer very high spatial accuracy and uniformity, together with the capability of producing extremely fine electrode structures. Microstrip proportional counters have now been variously reported having an energy resolution of better than 11 percent FWHM at 5.9 keV. They have been fabricated with anode bars down to 2 microns and on a variety of substrate materials including thin films which can be molded to different shapes. This review will examine the development of the microstrip detector with emphasis on the qualities which make this detector particularly interesting for use in astronomy.

  15. Influence of film thickness in THz active metamaterial devices: A comparison between superconductor and metal split-ring resonators

    NASA Astrophysics Data System (ADS)

    Singh, Ranjan; Roy Chowdhury, Dibakar; Xiong, Jie; Yang, Hao; Azad, Abul K.; Taylor, Antoinette J.; Jia, Q. X.; Chen, Hou-Tong

    2013-08-01

    We experimentally demonstrate thickness-dependent resonance tuning in planar terahertz superconducting metamaterials. Inductive-capacitive resonance of arrays of split-ring resonators fabricated from 50, 100, and 200 nm thick YBa2Cu3O7-δ (YBCO) and gold films were characterized and compared as a function of temperature. In the YBCO metamaterials the resonance frequency strongly depends on the thickness, and they show high thermal tunability in both resonance strength and frequency below the superconducting transition temperature, where the imaginary conductivity varies by three orders of magnitude. In contrast, the resonance in the gold metamaterials exhibits little thickness-dependence and very small tunability.

  16. Demonstration of a liquid core optical ring resonator sensor coupled with an ARROW waveguide array

    NASA Astrophysics Data System (ADS)

    White, Ian M.; Oveys, Hesam; Fan, Xudong; Smith, Terry L.; Zhang, Junying

    2007-02-01

    The liquid core optical ring resonator (LCORR) sensor is a newly developed capillary-based ring resonator that integrates microfluidics with photonic sensing technology. The circular cross-section of the capillary forms a ring resonator that supports whispering gallery modes (WGM). The WGM evanescent field is exposed to the capillary core and detects the aqueous samples conducted by the capillary using a label-free protocol. The high-Q of the WGM allows for repetitive light-analyte interaction, resulting in excellent sensitivity. Recently a detection limit of the LCORR on the order of 10 -6 refractive index units was reported. In this work, we have further integrated the LCORR with an anti-resonant reflective optical waveguide (ARROW) array for multiplexed sensor development. The ARROW, with an array of 8 waveguides separated by 250 microns each, consists of a core and a lower reflective double-layer with alternating high and low refractive index, and thus has a significant evanescent field above the waveguide. The WGM is excited at each LCORR/ARROW junction simultaneously when the LCORR is brought into contact with the ARROW array. We experimentally investigated the optimal waveguide geometry for WGM excitation using a range of waveguide heights from 2 to 5 microns. Furthermore, the LCORR/ARROW system is utilized for a biomolecule sensing demonstration. The LCORR/ARROW system is not only essential for assembling a robust, practical, and densely multiplexed sensor array, but also enables on-capillary flow analysis that has broad applications in capillary electrophoresis, chromatography, and lab-on-a-chip development.

  17. Tunable plasmon resonance in the nanobars and split ring resonator(SRR) composite structure

    NASA Astrophysics Data System (ADS)

    Xu, Haiqing; Li, Hongjian; Xiao, Gang; Chen, Qiao

    2016-10-01

    We have proposed a multi-band metamaterials composed of bars and planer SRR. There are three sharp peaks in the transmission spectra in the visible and near-infrared region, we find that the transmission spectra are highly tunable as the coupling and geometric parameters modifying, especially the third peak in the near-infrared region. When the gap distance between the two nanobar g1<14 nm, the original first peak will split, a new dip and peak will exist, which is results from the high-order plasmon resonance. When introducing asymmetry to the planer SRR, a new sharp peak accompany with a new sharp dip exists in the original second peak, which is originated from the strong electric field resonance. We also find that the proposed structures with sensing sensitivity of ~467 nm/RIU, which can be used for plasmonic sensor.

  18. Multiplexed infrared photodetection using resonant radio-frequency circuits

    SciTech Connect

    Liu, R.; Lu, R.; Gong, S.; Wasserman, D.; Roberts, C.; Allen, J. W.; Allen, M. S.; Wenner, B. R.

    2016-02-08

    We demonstrate a room-temperature semiconductor-based photodetector where readout is achieved using a resonant radio-frequency (RF) circuit consisting of a microstrip split-ring resonator coupled to a microstrip busline, fabricated on a semiconductor substrate. The RF resonant circuits are characterized at RF frequencies as function of resonator geometry, as well as for their response to incident IR radiation. The detectors are modeled analytically and using commercial simulation software, with good agreement to our experimental results. Though the detector sensitivity is weak, the detector architecture offers the potential for multiplexing arrays of detectors on a single read-out line, in addition to high speed response for either direct coupling of optical signals to RF circuitry, or alternatively, carrier dynamics characterization of semiconductor, or other, material systems.

  19. Multiplexed infrared photodetection using resonant radio-frequency circuits

    NASA Astrophysics Data System (ADS)

    Liu, R.; Lu, R.; Roberts, C.; Gong, S.; Allen, J. W.; Allen, M. S.; Wenner, B. R.; Wasserman, D.

    2016-02-01

    We demonstrate a room-temperature semiconductor-based photodetector where readout is achieved using a resonant radio-frequency (RF) circuit consisting of a microstrip split-ring resonator coupled to a microstrip busline, fabricated on a semiconductor substrate. The RF resonant circuits are characterized at RF frequencies as function of resonator geometry, as well as for their response to incident IR radiation. The detectors are modeled analytically and using commercial simulation software, with good agreement to our experimental results. Though the detector sensitivity is weak, the detector architecture offers the potential for multiplexing arrays of detectors on a single read-out line, in addition to high speed response for either direct coupling of optical signals to RF circuitry, or alternatively, carrier dynamics characterization of semiconductor, or other, material systems.

  20. Slow light in mass-produced, dispersion-engineered photonic crystal ring resonators.

    PubMed

    McGarvey-Lechable, Kathleen; Hamidfar, Tabassom; Patel, David; Xu, Luhua; Plant, David V; Bianucci, Pablo

    2017-02-20

    We present experimental results of photonic crystal ring resonators (PhCRRs) fabricated on the CMOS-compatible, silicon-on-insulator platform via 193-nm deep-UV lithography. Our dispersion-engineering design approach is compared to experimental results, showing very good agreement between theory and measurements. Specifically, we report a mean photonic band-edge wavelength of 1546.2 ± 5.8 nm, a 0.2% variation from our targeted band-edge wavelength of 1550 nm. Methods for the direct calculation of the experimental, discrete dispersion relation and extraction of intrinsic quality factors for a highly-dispersive resonator are discussed. A maximum intrinsic quality factor of ≈83,800 is reported, substantiating our design method and indicating that high-throughput optical lithography is a viable candidate for PhCRR fabrication. Finally, through comparison of the mean intrinsic quality and slowdown factors of the PhCRRs and standard ring resonators, we present evidence of an increase in light-matter interaction strength with simultaneous preservation of microcavity lifetimes.

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

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

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

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

    PubMed Central

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

    2015-01-01

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

  3. All-optical tuning of a magnetic-fluid-filled optofluidic ring resonator.

    PubMed

    Liu, Yang; Shi, Lei; Xu, Xinbiao; Zhao, Ping; Wang, Zheqi; Pu, Shengli; Zhang, Xinliang

    2014-08-21

    An all-optical tunable optofluidic ring resonator (OFRR) is proposed and experimentally demonstrated. The all-optical control of a silica microresonator is highly attractive, but it is difficult to realize because of the relatively weak Kerr effect and the absence of a plasma dispersion effect of silica. Here, we infuse a silica microcapillary-based optofluidic ring resonator with a magnetic fluid, into which pump light is injected by a fiber taper. Iron oxide nanoparticles dispersed in the magnetic fluid produce a strong pump light absorption, and this leads to a resonance shift of the silica microresonator due to the photothermal effect. To the best of our knowledge, this is the first scheme for all-optical tuning of an OFRR. A tuning sensitivity of up to 0.15 nm mW(-1) and a tuning range of 3.3 nm are achieved. With such excellent performance, the magnetic-fluid-filled OFRR has great potential in filtering, sensing, and signal processing applications.

  4. Graphene-Gold Nano-ring antenna for Dual-resonance optical application

    NASA Astrophysics Data System (ADS)

    Zarrabi, Ferdows B.; Mohaghegh, Mojtaba; Bazgir, Maryam; Arezoomand, Afsaneh Saee

    2016-01-01

    To achieve dual resonance qualification, we are suggested a sub-wavelength dual-ring Nano-antenna based on combination of Graphene and gold where Nano-Antenna with dual-resonance is attractive for spectroscopy and bio-sensing applications. The result shows that with these structures, we could be achieved dual-resonance characteristic of Infra red (IR) and optical regime. In addition, by biasing of the Graphene, we are attained a reconfigurable characteristic for our second resonance. Therefore, in this current research, the extinction, reflection and absorption cross section are studied for every structure and formation. For modeling the prototype Nano-antenna, SiN Substrate is selected with refractive index of 1.98 and silver with Palik optical characteristic for metal layer is modified. Simulation has been done with FDTD method. Of course, because of symmetry of the structure, the prototype Nano-antenna has similar manner for vertical or horizontal polarization. As a result, proposed Nano-antenna is useful for THz medical spectroscopy with simple method of designing and second frequency controlling only with graphene biasing. Here, we are debated about graphene placement and biasing interaction on the bonding and anti-bonding mode where we show that the gold and graphene interaction will affect on E-field distribution by making dipole or quad resonance.

  5. Symmetric and Asymmetric Split Ring Resonators for Biosensing at Terahertz Frequencies

    NASA Astrophysics Data System (ADS)

    Naranjo, Guillermo; Peralta, Xomalin

    2015-03-01

    Food allergies have become a major health concern around the world. Peanut allergies are particularly important because they affect over 5 million people in the United States. We are proposing to develop a metamaterial-based sensor for peanut allergens. The detection mechanism we will tap into is the change in a metamaterial's resonant response due to the presence of a biomolecule in the gap region. Using a commercial-grade simulator based on the finite-difference time-domain method, we have simulated the terahertz transmission and reflection spectra of three different split-ring resonator designs with and without a biomolecule present. By modifying the overall symmetry of the resonator and the geometry of the gap region, we have modified the resonant response and increased its sensitivity. The increased sensitivity is demonstrated by repeating the simulations with a layer of peroxidase conjugated immunoglobulin G (PX-IgG) in the gap region and quantifying the resulting resonant shift. These results are the basis for the proposed allergen sensors. UTSA MBRS-RISE Research Training Program.

  6. Optical waveguide biosensor based on cascaded Mach-Zehnder interferometer and ring resonator with Vernier effect

    NASA Astrophysics Data System (ADS)

    Jiang, Xianxin; Tang, Longhua; Song, Jinyan; Li, Mingyu; He, Jian-Jun

    2014-03-01

    Optical waveguide biosensors based on silicon-on-insulator (SOI) have been extensively investigated owing to its various advantages and many potential applications. In this article, we demonstrate a novel highly sensitive biosensor based on cascaded Mach-Zehnder interferometer (MZI) and ring resonator with the Vernier effect using wavelength interrogation. The experimental results show that the sensitivity reached 1,960 nm/RIU and 19,100 nm/RIU for sensors based on MZI alone and cascaded MZI-ring with Vernier effect, respectively. A biosensing application was also demonstrated by monitoring the interaction between goat and antigoat immunoglobulin G (IgG) pairs. This integrated high sensitivity biosensor has great potential for medical diagnostic applications.

  7. Lost in Jupiter's Shadow: Can Resonant Charge Variations Explain Dust Grain Sizes in the Main Ring?

    NASA Astrophysics Data System (ADS)

    Jontof-Hutter, Daniel; Hamilton, D. P.

    2012-10-01

    Interplanetary impacts onto the tiny moons Metis and Adrastea replenish Jupiter's main ring with dusty ejecta of all sizes. The equilibrium size distribution present in the rings at a given time is a function of production and loss mechanisms, both of which may be vary with particle size. Loss mechanisms include collisions and dynamical processes. Here we explore some of the latter. Grains tend to pick up negative electric charges due to motion through Jupiter's plasma environment, and positive charges from the photoelectric effect of sunlight. The periodic interruption of sunlight in Jupiter's shadow causes the equilibrium electric charge, and hence the Lorentz force, to resonate with the Kepler orbital frequency. The eccentricity increases for grains moving radially inwards during the shadow transit, and decreases when grains move outward in the shadow, hence the azimuthal location of pericenter is important. For smaller grains, the eccentricity increases monotonically until they collide with Jupiter. For much larger grains, precession due to both the Lorentz force and planetary oblateness causes the eccentricity to oscillate periodically. We explore the shadow instability in the main ring for a variety of uniform plasma density models, comparing numerical data with a semi-analytic approximation. We find that the effect of the shadow dwindles in importance for plasma that is either too sparse or too dense. In sparse plasma, the charging timescale slows, limiting the change in electric potential from sunlight to shadow. In dense plasma, charging currents from the plasma overwhelm the photoelectric effect in sunlight, also resulting in a small change in electric potential. Between these two regimes, the shadow resonance efficiently removes grains up to a particular size threshold in the main ring. This size-dependent loss mechanism may contribute to the observed flattening in the size distribution index for smaller grains.

  8. All-optical XNOR gate based on 2D photonic-crystal ring resonators

    NASA Astrophysics Data System (ADS)

    Moniem, Tamer A.

    2017-02-01

    A novel all-optical XNOR gate is proposed, which combines the nonlinear Kerr effect with photonic-crystal ring resonators (PCRRs). The total size of the proposed optical XNOR gate based on photonic crystals with a square lattice of silicon rods is equal to 35 × 21 μm. The proposed structure has a bandgap in the range from 0.32 to 0.44. To confirm the operation and feasibility of the overall system use is made of analytical and numerical simulation using the dimensional finite difference time domain (FDTD) and plane wave expansion (PWE) methods.

  9. Characterization on the effect of linear stress birefringence in a total reflection prism (TRP) ring resonator

    NASA Astrophysics Data System (ADS)

    Li, Dong; Bi, Chao; Jiang, Yajun; Zhao, Jianlin

    2016-10-01

    Based on the theory of Jones matrix and the condition of eigenmode self-consistency, we analyze the effect of linear stress birefringence of prismon the beam polarization (described with the ellipticity and loss of the eigenmodes) and null drift (described with the output frequency difference of the eigenmodes) in a TRP resonator. It is found that the linear stress birefringence of prisms can cause larger polarization ellipticity for both CW (clockwise) and CCW (counterclockwise) beams. The results may be useful for designing and optimizing the structure of super high precision TRP ring laser gyroscopes.

  10. Coupling of two counterpropagating modes in nonlinear split-ring resonators' chain

    NASA Astrophysics Data System (ADS)

    Cui, Wei-na; Lu, Wen; Li, Hong-xia; Sun, Min; Zhu, Yong-yuan

    2016-05-01

    The two coupled counterpropagating nonlinear magnetoinductive wave modes are analyzed theoretically in split ring resonator chain with Kerr nonlinear interaction. Starting from a general nonlinear lattice equation based on a quasi-discreteness approach we derive two coupled nonlinear Schrödinger equations governing the evolution of the slowly varying envelopes of these modes. It is shown that this system supports backward- and forward-propagating vector solitons of the bright-bright and dark-dark type through a cross-phase modulation.

  11. Fine golden rings: Tunable surface plasmon resonance from assembled nanorods in topological defects of liquid crystals

    SciTech Connect

    Lee, Elaine; Xia, Yu; Ferrier, Jr., Robert C.; Kim, Hye -Na; Gharbi, Mohamed A.; Stebe, Kathleen J.; Kamien, Randall D.; Composto, Russell J.; Yang, Shu

    2016-02-08

    Unprecedented, reversible, and dynamic control over an assembly of gold nanorods dispersed in liquid crystals (LC) is demonstrated. The LC director field is dynamically tuned at the nanoscale using microscale ring confinement through the interplay of elastic energy at different temperatures, thus fine-tuning its core replacement energy to reversibly sequester nanoscale inclusions at the microscale. As a result, this leads to shifts of 100 nm or more in the surface plasmon resonance peak, an order of magnitude greater than any previous work with AuNR composites.

  12. Ultra-sensitive Chip-based Photonic Temperature Sensor Using Ring Resonator Structures

    DTIC Science & Technology

    2014-02-10

    Sensor, Sensors Technology (Momentum Press LLC, 2009). 7. R. Price, “The Platinum resistance Thermometer ,” Platin. Met. Rev. 3, 78–87 (1959). 8. G...F. Strouse, “Standard Platinum Resistance Thermometer Calibrations fromthe Ar TP to the Ag FP,” NIST Special Publication 250–250–81 (2008). 9. S. J...Strouse, “Sapphire whispering gallery thermometer ,” Int. J. Thermophys. 28(6), 1812–1821 (2007). 16. W. W. Rigrod, “The optical ring resonator,” Bell

  13. Ultra-sensitive chip-based photonic temperature sensor using ring resonator structures.

    PubMed

    Xu, Haitan; Hafezi, Mohammad; Fan, J; Taylor, J M; Strouse, G F; Ahmed, Zeeshan

    2014-02-10

    Resistance thermometry provides a time-tested method for taking temperature measurements. However, fundamental limits to resistance-based approaches has produced considerable interest in developing photonic temperature sensors to leverage advances in frequency metrology and to achieve greater mechanical and environmental stability. Here we show that silicon-based optical ring resonator devices can resolve temperature differences of 1 mK using the traditional wavelength scanning methodology. An even lower noise floor of 80 μK for measuring temperature difference is achieved in the side-of-fringe, constant power mode measurement.

  14. An efficient optical biochemical sensor based on a polyatomic photonic crystal ring resonator

    NASA Astrophysics Data System (ADS)

    Wang, Daobin; Liu, Yanjun; Yuan, Lihua; Lei, Jingli; Li, Xiaoxiao; wu, Gang; Hou, Shanglin

    2016-08-01

    In this paper, we introduce and investigate a design concept for a polyatomic photonic crystal ring resonator (PCRR). In contrast to conventional sensors, this PCRR comprises two different branching waveguides (WG), which are all oriented in the same lattice direction, but with different optical propagation properties due to the binary nature of the diatomic square lattice. Based on this new scheme, an on-chip biochemical sensor is proposed. Electromagnetic analysis, PWE and FDTD numerical techniques, were used to investigate the sensing performance. Our results show that such a sensor can efficiently detect small changes in the refractive index within the sensing area.

  15. Investigation of a Fiberoptic Device Based on a Long Period Grating in a Ring Resonator

    PubMed Central

    Corcione, Cinzia; Troia, Benedetto; De Leonardis, Francesco; Passaro, Vittorio M. N.

    2016-01-01

    A fiberoptic architecture based on a ring resonator (RR) including a typical long period grating (LPG) was investigated. The interactions between the fundamental core mode (LP01 or HE11) coupled to the RR and the cladding mode (LP08), excited into the cavity by means of the LPG, allow a peculiar spectral response characterized by two splitting resonances to be achieved. The new LPGRR architecture is investigated theoretically and a mathematical modelling based on the transfer matrix method (TMM) is proposed. The theoretical results are compared with the experiments measured by an open-loop LPG, while the performance of the relative LPGRR was estimated by a theoretical parametric analysis. Finally, an overview of the possible LPGRR sensing applications is provided by investigating the features of a strain sensor operating in different environmental conditions. PMID:27563910

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

    PubMed Central

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

    2016-01-01

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

  17. Magnetically tunable negative permeability metamaterial composed by split ring resonators and ferrite rods.

    PubMed

    Kang, Lei; Zhao, Qian; Zhao, Hongjie; Zhou, Ji

    2008-06-09

    We experimentally demonstrate a tunable negative permeability metamaterial (NPM) at microwave frequencies by introducing yttrium iron garnet (YIG) rods into a periodic array of split ring resonators (SRRs). Different from those tuned by controlling the capacitance of equivalent LC circuit of SRR, this metamaterial is based on a mechanism of magnetically tuning the inductance via the active ambient effective permeability. For magnetic fields from 0 to 2000 Oe and from 3200 to 6000 Oe, the resonance frequencies of the metamaterial can blueshift about 350 MHz and redshift about 315 MHz, respectively. Both shifts are completely continuous and reversible. Correspondingly, the tunable negative permeabilities are widened by about 360 MHz and 200 MHz compared to that without YIG rods.

  18. Circuit model optimization of a nano split ring resonator dimer antenna operating in infrared spectral range

    SciTech Connect

    Gneiding, N.; Zhuromskyy, O.; Peschel, U.; Shamonina, E.

    2014-10-28

    Metamaterials are comprised of metallic structures with a strong response to incident electromagnetic radiation, like, for example, split ring resonators. The interaction of resonator ensembles with electromagnetic waves can be simulated with finite difference or finite elements algorithms, however, above a certain ensemble size simulations become inadmissibly time or memory consuming. Alternatively a circuit description of metamaterials, a well developed modelling tool at radio and microwave frequencies, allows to significantly increase the simulated ensemble size. This approach can be extended to the IR spectral range with an appropriate set of circuit element parameters accounting for physical effects such as electron inertia and finite conductivity. The model is verified by comparing the coupling coefficients with the ones obtained from the full wave numerical simulations, and used to optimize the nano-antenna design with improved radiation characteristics.

  19. Chaotic parametric soliton-like pulses in ferromagnetic-film active ring resonators

    SciTech Connect

    Grishin, S. V. Golova, T. M.; Morozova, M. A.; Romanenko, D. V.; Seleznev, E. P.; Sysoev, I. V.; Sharaevskii, Yu. P.

    2015-10-15

    The generation of quasi-periodic sequences of parametric soliton-like pulses in an active ring resonator with a ferromagnetic film via the three-wave parametric instability of a magnetostatic surface wave is studied theoretically and experimentally. These dissipative structures form in time due to the competition between the cubic nonlinearity caused by parametric coupling between spin waves and the time dispersion caused by the resonant cavity that is present in a self-oscillatory system. The development of dynamic chaos due to the parametric instability of a magnetostatic surface wave results in irregular behavior of a phase. However, this behavior does not break a quasi-periodic pulse sequence when the gain changes over a wide range. The generated soliton-like pulses have a chaotic nature, which is supported by the maximum Lyapunov exponent estimated from experimental time series.

  20. Split-Ring Resonator-Based Strain Sensor on Flexible Substrates for Glaucoma Detection

    NASA Astrophysics Data System (ADS)

    Ekinci, Gizem; Deniz Yalcinkaya, Arda; Dundar, Gunhan; Torun, Hamdi

    2016-10-01

    This paper presents split-ring resonator-based strain sensors designed and characterized for glaucoma detection application. The geometry of the sensor is optimized such that it can be embedded in a contact lens. Silver conductive paint is to form the sensors realized on flexible substrates made of cellulose acetate and latex rubber. The devices are excited and interrogated using a pair of monopole antennas and the characteristics of devices with different curvature profiles are obtained. The sensitivity of the device, i.e. the change in resonant frequency for a unit change in radius of curvature, on acetate film is calculated as -4.73 MHz/mm and the sensitivity of the device on latex is 33.2 MHz/mm. The results indicate that the demonstrated device is suitable for glaucoma diagnosis.

  1. Fiber Bragg grating ring resonators under rotation for angular velocity sensing.

    PubMed

    Campanella, C E; De Leonardis, F; Passaro, V M N

    2015-05-20

    In this paper we investigate the possibility of using hybrid resonators based on fiber Bragg grating ring resonators (FBGRRs) and π-shifted FBGRRs (i.e., defective FBGRRs) as rotation sensitive elements for gyroscope applications. In particular, we model the conventional fiber Bragg grating (FBG) with the coupled mode theory by taking into account how the Sagnac effect, induced by the rotation, modifies the eigenvalues, the photonic band gap, and the spectral response of the FBG. Then, on the basis of the FBG model under rotation conditions, the spectral responses of the FBGRR and π-FBGRR have been evaluated, confirming that the Sagnac effect manifests itself with a spectral shift of the eigensolutions. This physical investigation can be exploited for opening new ways in the optical gyroscope platforms.

  2. The superconducting quantum interference device microstrip amplifier: Computer models

    SciTech Connect

    Mu''ck, Michael; Clarke, John

    2000-12-01

    Computer models are presented for a microstrip amplifier based on a dc superconducting quantum interference device (SQUID). In this device, the signal is applied between one end of the spiral input coil and the square washer on which it is deposited. The amplifier exhibits substantial power gain when the signal frequency is such that a half wavelength is approximately equal to the length of the microstrip formed by the coil and the groundplane. The resonant frequency is lowered significantly by the inductance of the square washer transformed into the input coil; this reduction is consistent with predictions of a simple model and with analog simulations. With the washer grounded, the gain of the amplifier peaks at a frequency that is lowered from the unloaded resonant frequency by the damping of the resistance associated with the source. The position and magnitude of the peak are in good agreement with both a lumped circuit model and with a model representing the microstrip as a transmission line. When the counter electrode of the SQUID is grounded and the washer floats, feedback from the output of the SQUID to the input via the capacitance of the microstrip plays a major role and is well described by simulations using the transmission line model. Measurements of the input impedance of the microstrip amplifier show that the return loss can be positive or negative, depending on the sign of the feedback and whether the frequency is above or below the resonant frequency. This behavior is in good accord with simulations.

  3. Planar Microwave Sensor for Theranostic Therapy of Organic Tissue Based on Oval Split Ring Resonators

    PubMed Central

    Reimann, Carolin; Puentes, Margarita; Maasch, Matthias; Hübner, Frank; Bazrafshan, Babak; Vogl, Thomas J.; Damm, Christian; Jakoby, Rolf

    2016-01-01

    Microwave sensors in medical environments play a significant role due to the contact-less and non-invasive sensing mechanism to determine dielectric properties of tissue. In this work, a theranostic sensor based on Split Ring Resonators (SRRs) is presented that provides two operation modes to detect and treat tumor cells, exemplary in the liver. For the detection mode, resonance frequency changes due to abnormalities are evaluated, and in the treatment mode, microwave ablation is performed. The planar sensor structure can be integrated into a needle like a surgery tool that evokes challenges concerning size limitations and biocompatibility. To meet the size requirements and provide a reasonable operating frequency, properties of oval shaped SRRs are investigated. By elongating the radius of the SRR in one direction, the resonance frequency can be decreased significantly compared to circular SRR by a factor of two below 12 GHz. In order to validate the detection and treatment characteristics of the sensor, full wave simulations and measurements are examined. Clear resonance shifts are detected for loading the sensor structures with phantoms mimicking healthy and malignant tissue. For treatment mode evaluation, ex vivo beef liver tissue was ablated leading to a lesion zone 1.2 cm × 1 cm × 0.3 cm with a three minute exposure of maximum 2.1 W. PMID:27618050

  4. Resonance hybridization and near field properties of strongly coupled plasmonic ring dimer-rod nanosystem

    SciTech Connect

    Koya, Alemayehu Nana; Ji, Boyu; Hao, Zuoqiang; Lin, Jingquan

    2015-09-21

    Combined effects of polarization, split gap, and rod width on the resonance hybridization and near field properties of strongly coupled gold dimer-rod nanosystem are comparatively investigated in the light of the constituent nanostructures. By aligning polarization of the incident light parallel to the long axis of the nanorod, introducing small split gaps to the dimer walls, and varying width of the nanorod, we have simultaneously achieved resonance mode coupling, huge near field enhancement, and prolonged plasmon lifetime. As a result of strong coupling between the nanostructures and due to an intense confinement of near fields at the split and dimer-rod gaps, the extinction spectrum of the coupled nanosystem shows an increase in intensity and blueshift in wavelength. Consequently, the near field lifespan of the split-nanosystem is prolonged in contrast to the constituent nanostructures and unsplit-nanosystem. On the other hand, for polarization of the light perpendicular to the long axis of the nanorod, the effect of split gap on the optical responses of the coupled nanosystem is found to be insignificant compared to the parallel polarization. These findings and such geometries suggest that coupling an array of metallic split-ring dimer with long nanorod can resolve the huge radiative loss problem of plasmonic waveguide. In addition, the Fano-like resonances and immense near field enhancements at the split and dimer-rod gaps imply the potentials of the nanosystem for practical applications in localized surface plasmon resonance spectroscopy and sensing.

  5. Ultraviolet Signposts of Resonant Dynamics in the Starburst-ringed SAB Galaxy M94 (NGC 4736)

    NASA Astrophysics Data System (ADS)

    Waller, William H.; Fanelli, Michael N.; Keel, William C.; Bohlin, Ralph; Collins, Nicholas R.; Madore, Barry F.; Marcum, Pamela M.; Neff, Susan G.; O'Connell, Robert W.; Offenberg, Joel D.; Roberts, Morton S.; Smith, Andrew M.; Stecher, Theodore P.

    2001-03-01

    The dynamic orchestration of star-birth activity in the starburst-ringed galaxy M94 (NGC 4736) is investigated using images from the Ultraviolet Imaging Telescope (UIT; far-ultraviolet [FUV] band), Hubble Space Telescope (HST; near-ultraviolet [NUV] band), Kitt Peak 0.9 m telescope (Hα, R, and I bands), and Palomar 5 m telescope (B band), along with spectra from the International Ultraviolet Explorer (IUE) and the Lick 1 m telescope. The wide-field UIT image shows FUV emission from (1) an elongated nucleus, (2) a diffuse inner disk, where Hα is observed in absorption, (3) a bright inner ring of H II regions at the perimeter of the inner disk (R=48"=1.1 kpc), and (4) two 500 pc size knots of hot stars exterior to the ring on diametrically opposite sides of the nucleus (R=130"=2.9 kpc). The HST Faint Object Camera image resolves the NUV emission from the nuclear region into a bright core and a faint 20" long ``minibar'' at a position angle of 30°. Optical and IUE spectroscopy of the nucleus and diffuse inner disk indicates a ~107-108 yr old stellar population from low-level star-birth activity blended with some LINER activity. Analysis of the Hα-, FUV-, NUV-, B-, R-, and I-band emissions, along with other observed tracers of stars and gas in M94, indicates that most of the star formation is being orchestrated via ring-bar dynamics, involving the nuclear minibar, inner ring, oval disk, and outer ring. The inner starburst ring and bisymmetric knots at intermediate radius, in particular, argue for bar-mediated resonances as the primary drivers of evolution in M94 at the present epoch. Similar processes may be governing the evolution of the ``core-dominated'' galaxies that have been observed at high redshift. The gravitationally lensed ``Pretzel Galaxy'' (0024+1654) at a redshift of ~1.5 provides an important precedent in this regard.

  6. Design and fabrication of a 20 MHz pn-diode silicon ring resonator with in-plane vibration mode

    NASA Astrophysics Data System (ADS)

    Asahi, Yoichi; Tanigawa, Hiroshi; Nishino, Tomoki; Furutsuka, Takashi; Suzuki, Kenichiro

    2016-06-01

    In this paper, we report a new microelectromechanical system (MEMS) resonator based on the pn-diode principle. The pn-diode-based resonator can eliminate the narrow gap that conventional electrostatic MEMS resonators need between driving electrodes. This is expected to solve several serious problems related to fabrication, packaging, and lifetime. However, the resonators previously reported had pn-diodes formed in the vertical direction. Because the resonant frequency is determined by the thickness of the resonator plate, the resonant frequency in formed resonators cannot be changed in the same chip. To solve this problem, we newly design a pn-diode resonator with a lateral vibration. Because the resonant frequency is determined by plate width, this new resonator can provide various resonators with different frequencies in a chip, which is most suitable for the integration of MEMS resonators with electronic circuits. Our research objective at present is related to design and fabrication. By using a simulator, we design a ring resonator of 20 MHz. In the fabrication, we develop a technique of using ion implantation to form a 3-µm-thick pn-diode. The results shown here are very useful for improving the MEMS resonators.

  7. Harmonic Resonant Kicker Design for the MEIC Electron Circular Cooler Ring

    SciTech Connect

    Huang, Yulu; Wang, Haipeng; Rimmer, Robert A.

    2015-09-01

    Bunched-beam electron cooling of the high-energy ion beam emittance may be a crucial technology for the proposed Medium energy Electron Ion Collider (MEIC) to achieve its design luminosity. A critical component is a fast kicker system in the Circular Ring (CR) that periodically switches electron bunches in and out of the ring from and to the driver Energy Recovery Linac (ERL). Compared to a conventional strip-line type kicker, a quarter-wave resonator (QWR)-based deflecting structure has a much higher shunt impedance and so requires much less RF power. The cavity has been designed to resonate simultaneously at many harmonic modes that are integer multiples of the fundamental mode. In this way the resulting waveform will kick only a subset of the circulating bunches. In this paper, analytical shunt impedance optimization, the electromagnetic simulations of this type of cavity, as well as tuner and coupler concept designs to produce 5 odd and 5 even harmonics of 47.63MHz will be presented, in order to kick every 10th bunch in a 476.3 MHz bunch train.

  8. Selective and reversible ammonia gas detection with nanoporous film functionalized silicon photonic micro-ring resonator.

    PubMed

    Yebo, Nebiyu A; Sree, Sreeprasanth Pulinthanathu; Levrau, Elisabeth; Detavernier, Christophe; Hens, Zeger; Martens, Johan A; Baets, Roel

    2012-05-21

    Portable, low cost and real-time gas sensors have a considerable potential in various biomedical and industrial applications. For such applications, nano-photonic gas sensors based on standard silicon fabrication technology offer attractive opportunities. Deposition of high surface area nano-porous coatings on silicon photonic sensors is a means to achieve selective, highly sensitive and multiplexed gas detection on an optical chip. Here we demonstrate selective and reversible ammonia gas detection with functionalized silicon-on-insulator optical micro-ring resonators. The micro-ring resonators are coated with acidic nano-porous aluminosilicate films for specific ammonia sensing, which results in a reversible response to NH(3)with selectivity relative to CO(2). The ammonia detection limit is estimated at about 5 ppm. The detectors reach a steady response to NH(3) within 30 and return to their base level within 60 to 90 seconds. The work opens perspectives on development of nano-photonic sensors for real-time, non-invasive, low cost and light weight biomedical and industrial sensing applications.

  9. Self-oscillation of standing spin wave in ring resonator with proportional-integral-derivative control

    SciTech Connect

    Peng, B.; Urazuka, Y.; Chen, H.; Oyabu, S.; Otsuki, H.; Tanaka, T. Matsuyama, K.

    2014-05-07

    We report on numerical analysis on self-oscillation of standing spin wave excited in a nanostructured active ring resonator, consists of a ferromagnetic nanowire with perpendicular anisotropy. The confined resonant modes are along the nanowire length. A positive feedback with proportional-integral-derivative gain control was adopted in the active ring. Stable excitation of the 1st order standing spin wave has been demonstrated with micromagnetic simulations, taking into account the thermal effect with a random field model. The stationary standing spin wave with a pre-determined set variable of precession amplitude was attained within 20 ns by optimizing the proportional-integral-derivative gain control parameters. The result indicates that a monochromatic oscillation frequency f{sub osc} is extracted from the initial thermal fluctuation state and selectively amplified with the positive feedback loop. The obtained f{sub osc} value of 5.22 GHz practically agrees with the theoretical prediction from dispersion relation of the magneto static forward volume wave. It was also confirmed that the f{sub osc} change due to the temperature rise can be compensated with an external perpendicular bias field H{sub b}. The observed quick compensation time with an order of nano second suggests the fast operation speed in the practical device application.

  10. High temperature spin dynamics in linear magnetic chains, molecular rings, and segments by nuclear magnetic resonance

    SciTech Connect

    Adelnia, Fatemeh; Lascialfari, Alessandro; Mariani, Manuel; Ammannato, Luca; Caneschi, Andrea; Rovai, Donella; Winpenny, Richard; Timco, Grigore; Corti, Maurizio Borsa, Ferdinando

    2015-05-07

    We present the room temperature proton nuclear magnetic resonance (NMR) nuclear spin-lattice relaxation rate (NSLR) results in two 1D spin chains: the Heisenberg antiferromagnetic (AFM) Eu(hfac){sub 3}NITEt and the magnetically frustrated Gd(hfac){sub 3}NITEt. The NSLR as a function of external magnetic field can be interpreted very well in terms of high temperature spin dynamics dominated by a long time persistence of the decay of the two-spin correlation function due to the conservation of the total spin value for isotropic Heisenberg chains. The high temperature spin dynamics are also investigated in Heisenberg AFM molecular rings. In both Cr{sub 8} closed ring and in Cr{sub 7}Cd and Cr{sub 8}Zn open rings, i.e., model systems for a finite spin segment, an enhancement of the low frequency spectral density is found consistent with spin diffusion but the high cut-off frequency due to intermolecular anisotropic interactions prevents a detailed analysis of the spin diffusion regime.

  11. Resonance and phase shift in an open Aharonov-Bohm ring with an embedded quantum dot.

    PubMed

    Hedin, Eric R; Joe, Yong S; Satanin, Arkady M

    2009-01-07

    The transmission and phase properties of electron transport through a quantum dot (QD) with variable coupling to a third-terminal probe are investigated analytically for the case of the QD connected directly to source and drain reservoirs and when the QD is embedded in one arm of an Aharonov-Bohm (AB) ring. Using the tight-binding model, explicit analytical expressions of the transmission through the QD for each case are given. Expressions for the conductance with coupling to the third terminal, which breaks unitarity and phase-locking, are also given. It is shown that in a three-terminal interferometer the zero of the Fano resonance in the transmission moves off the real energy axis for finite values of the coupling parameter. The zero orbits around the pole in the complex energy plane as a function of magnetic flux through the ring, and can be returned to the real energy axis unless the coupling parameter exceeds a critical value. With the QD embedded in one arm of the AB ring, the electron transmission and the transmission phase, and the phase of the AB oscillations, are described in relation to the degree of coupling to the third-terminal probe which opens the interferometer. By tuning the degree of coupling to the probe, it is shown that the phase of the AB oscillations can be made to match the intrinsic phase of the QD, facilitating experimental characterization of the phase response of the QD.

  12. Novel microwave photonic fractional Hilbert transformer using a ring resonator-based optical all-pass filter.

    PubMed

    Zhuang, Leimeng; Khan, Muhammad Rezaul; Beeker, Willem; Leinse, Arne; Heideman, René; Roeloffzen, Chris

    2012-11-19

    We propose and demonstrate a novel wideband microwave photonic fractional Hilbert transformer implemented using a ring resonator-based optical all-pass filter. The full programmability of the ring resonator allows variable and arbitrary fractional order of the Hilbert transformer. The performance analysis in both frequency and time domain validates that the proposed implementation provides a good approximation to an ideal fractional Hilbert transformer. This is also experimentally verified by an electrical S21 response characterization performed on a waveguide realization of a ring resonator. The waveguide-based structure allows the proposed Hilbert transformer to be integrated together with other building blocks on a photonic integrated circuit to create various system-level functionalities for on-chip microwave photonic signal processors. As an example, a circuit consisting of a splitter and a ring resonator has been realized which can perform on-chip phase control of microwave signals generated by means of optical heterodyning, and simultaneous generation of in-phase and quadrature microwave signals for a wide frequency range. For these functionalities, this simple and on-chip solution is considered to be practical, particularly when operating together with a dual-frequency laser. To our best knowledge, this is the first-time on-chip demonstration where ring resonators are employed to perform phase control functionalities for optical generation of microwave signals by means of optical heterodyning.

  13. Electrically Conductive Photopatternable Silver Paste for High-Frequency Ring Resonator and Band-Pass Filter

    NASA Astrophysics Data System (ADS)

    Umarji, Govind; Qureshi, Nilam; Gosavi, Suresh; Mulik, Uttam; Kulkarni, Atul; Kim, Taesung; Amalnerkar, Dinesh

    2017-02-01

    In conventional thick-film technology, there are often problems associated with poor edges, rough surfaces, and reproducibility due to process limitations, especially for high-frequency applications. These difficulties can be circumvented by using thin-film technology, but process cost and complexity remain major concerns. In this context, photopatternable thick-film technology can offer a viable alternative due to its Newtonian rheology, which can facilitate formation of the required sharp edges. We present herein a unique attempt to formulate a photopatternable silver paste with organic (photosensitive polymer) to inorganic (silver and glass) ratio of 30:70, developed in-house by us for fabrication of thick-film-based ring resonator and band-pass filter components. The ring resonator and band-pass component structures were realized by exposing screen-printed film to ultraviolet light at wavelength of 315 nm to 400 nm for 30 s to crosslink the photosensitive polymer. The pattern was subsequently developed using 1% sodium carbonate aqueous solution. For comparison, conventional silver and silver-palladium thick films were produced using in-house formulations. The surface topology and microstructural features were examined by stereomicroscopy and scanning electron microscopy. The smoothness and edge definition of the film were assessed by profilometry. The resistivity of the samples was observed and remained in the range from 3.4 μΩ cm to 3.6 μΩ cm. The electrical properties were compared by measuring the insertion loss characteristics. The results revealed that the ring resonator fabricated using the photopatternable silver paste exhibited better high-frequency properties compared with components based on conventional silver or silver-palladium paste, especially in terms of the resonant frequency of 10.1 GHz (versus 10 GHz designed) with bandwidth of 80 MHz. Additionally, the band-pass filter fabricated using the photopatternable silver paste displayed better

  14. Finite-Element Electromagnetic Simulation of a Volume Coil with Slotted End-Rings for Magnetic Resonance Imaging

    NASA Astrophysics Data System (ADS)

    Vazquez, J. F.; Rodriguez, A. O.

    2008-08-01

    Radiofrequency volume coils are still a vital part to detect the magnetic resonance signal. This is mainly due to its highly uniform field over large regions of interest at expense of a relatively low signal-to-noise ratio. In this work, a new volume coil design with slotted end-rings is proposed for high field magnetic resonance imaging applications and, its electromagnetic properties studied via a numerical study. The slotted end-rings avoid breaking the coil structure into small segments degrading the coil performance and, improving the poor signal at the end-rings usually found in the traditional birdcage coil. Numerical simulations were evaluated by solving Maxwell's equations with the finite element method. Hence, both the electric and magnetic fields were evaluated and presented in the form of bi-dimensional images for the slotted end-ring coil and the birdcage coil for comparison purposes. From the magnetic field images of both coil designs, uniformity profiles were calculated at the midsection and the end-rings of the coil and compared. A substantial improvement can be appreciated at the end-rings for the slotted end-ring coil whereas for the midsection it had an acceptable enhancement. These encouraging results suggest that the slotted end-ring coil have an improved performance compared to the birdcage coil.

  15. Coupling effect combined with incident polarization to modulate double split-ring-resonator in terahertz frequency range

    NASA Astrophysics Data System (ADS)

    Zhu, Mei; Lin, Yu-Sheng; Lee, Chengkuo

    2014-11-01

    This work examines the coupling effect in concentric double split-ring-resonator devices in terahertz (THz) range when the inner ring changes its relative orientation to the outer ring. Through detailed analysis on the simulation results of surface current and electrical field distributions, we look into the changes of inductance and capacitance in the system caused by structural layouts, and present a set of coherent theory that is solely rooted in the inductance-capacitance circuit analogy to systematically account for the resonance change. Such coupling effect combined with polarization of the incident wave is further explored to demonstrate continuous modulation of THz resonances. A variation range of transmission intensity from 20% to 80% has been successfully achieved. These experimental results demonstrate the promise of realizing future tunable THz filters by means of rotating sub-structures of the device only.

  16. Complementary Split-Ring Resonator-Loaded Microfluidic Ethanol Chemical Sensor

    PubMed Central

    Salim, Ahmed; Lim, Sungjoon

    2016-01-01

    In this paper, a complementary split-ring resonator (CSRR)-loaded patch is proposed as a microfluidic ethanol chemical sensor. The primary objective of this chemical sensor is to detect ethanol’s concentration. First, two tightly coupled concentric CSRRs loaded on a patch are realized on a Rogers RT/Duroid 5870 substrate, and then a microfluidic channel engraved on polydimethylsiloxane (PDMS) is integrated for ethanol chemical sensor applications. The resonant frequency of the structure before loading the microfluidic channel is 4.72 GHz. After loading the microfluidic channel, the 550 MHz shift in the resonant frequency is ascribed to the dielectric perturbation phenomenon when the ethanol concentration is varied from 0% to 100%. In order to assess the sensitivity range of our proposed sensor, various concentrations of ethanol are tested and analyzed. Our proposed sensor exhibits repeatability and successfully detects 10% ethanol as verified by the measurement set-up. It has created headway to a miniaturized, non-contact, low-cost, reliable, reusable, and easily fabricated design using extremely small liquid volumes. PMID:27801842

  17. Highly tunable hybrid metamaterials employing split-ring resonators strongly coupled to graphene surface plasmons

    NASA Astrophysics Data System (ADS)

    Liu, Peter Q.; Luxmoore, Isaac J.; Mikhailov, Sergey A.; Savostianova, Nadja A.; Valmorra, Federico; Faist, Jérôme; Nash, Geoffrey R.

    2015-11-01

    Metamaterials and plasmonics are powerful tools for unconventional manipulation and harnessing of light. Metamaterials can be engineered to possess intriguing properties lacking in natural materials, such as negative refractive index. Plasmonics offers capabilities of confining light in subwavelength dimensions and enhancing light-matter interactions. Recently, the technological potential of graphene-based plasmonics has been recognized as the latter features large tunability, higher field-confinement and lower loss compared with metal-based plasmonics. Here, we introduce hybrid structures comprising graphene plasmonic resonators coupled to conventional split-ring resonators, thus demonstrating a type of highly tunable metamaterial, where the interaction between the two resonances reaches the strong-coupling regime. Such hybrid metamaterials are employed as high-speed THz modulators, exhibiting ~60% transmission modulation and operating speed in excess of 40 MHz. This device concept also provides a platform for exploring cavity-enhanced light-matter interactions and optical processes in graphene plasmonic structures for applications including sensing, photo-detection and nonlinear frequency generation.

  18. Highly tunable hybrid metamaterials employing split-ring resonators strongly coupled to graphene surface plasmons.

    PubMed

    Liu, Peter Q; Luxmoore, Isaac J; Mikhailov, Sergey A; Savostianova, Nadja A; Valmorra, Federico; Faist, Jérôme; Nash, Geoffrey R

    2015-11-20

    Metamaterials and plasmonics are powerful tools for unconventional manipulation and harnessing of light. Metamaterials can be engineered to possess intriguing properties lacking in natural materials, such as negative refractive index. Plasmonics offers capabilities of confining light in subwavelength dimensions and enhancing light-matter interactions. Recently, the technological potential of graphene-based plasmonics has been recognized as the latter features large tunability, higher field-confinement and lower loss compared with metal-based plasmonics. Here, we introduce hybrid structures comprising graphene plasmonic resonators coupled to conventional split-ring resonators, thus demonstrating a type of highly tunable metamaterial, where the interaction between the two resonances reaches the strong-coupling regime. Such hybrid metamaterials are employed as high-speed THz modulators, exhibiting ∼60% transmission modulation and operating speed in excess of 40 MHz. This device concept also provides a platform for exploring cavity-enhanced light-matter interactions and optical processes in graphene plasmonic structures for applications including sensing, photo-detection and nonlinear frequency generation.

  19. Highly tunable hybrid metamaterials employing split-ring resonators strongly coupled to graphene surface plasmons

    PubMed Central

    Liu, Peter Q.; Luxmoore, Isaac J.; Mikhailov, Sergey A.; Savostianova, Nadja A.; Valmorra, Federico; Faist, Jérôme; Nash, Geoffrey R.

    2015-01-01

    Metamaterials and plasmonics are powerful tools for unconventional manipulation and harnessing of light. Metamaterials can be engineered to possess intriguing properties lacking in natural materials, such as negative refractive index. Plasmonics offers capabilities of confining light in subwavelength dimensions and enhancing light–matter interactions. Recently, the technological potential of graphene-based plasmonics has been recognized as the latter features large tunability, higher field-confinement and lower loss compared with metal-based plasmonics. Here, we introduce hybrid structures comprising graphene plasmonic resonators coupled to conventional split-ring resonators, thus demonstrating a type of highly tunable metamaterial, where the interaction between the two resonances reaches the strong-coupling regime. Such hybrid metamaterials are employed as high-speed THz modulators, exhibiting ∼60% transmission modulation and operating speed in excess of 40 MHz. This device concept also provides a platform for exploring cavity-enhanced light–matter interactions and optical processes in graphene plasmonic structures for applications including sensing, photo-detection and nonlinear frequency generation. PMID:26584781

  20. Suppression of Nonlinear Interactions in Resonant Macroscopic Quantum Devices: The Example of the Solid-State Ring Laser Gyroscope

    SciTech Connect

    Schwartz, Sylvain; Feugnet, Gilles; Pocholle, Jean-Paul; Gutty, Francois; Bouyer, Philippe

    2008-05-09

    We report fine-tuning of nonlinear interactions in a solid-state ring laser gyroscope by vibrating the gain medium along the cavity axis. We demonstrate both experimentally and theoretically that nonlinear interactions vanish for some values of the vibration parameters, leading to quasi-ideal rotation sensing. We eventually point out that our conclusions can be mapped onto other subfields of physics such as ring-shaped superfluid configurations, where nonlinear interactions could be tuned by using Feshbach resonance.

  1. Formation of Janus and Epimetheus from Saturn's rings as coorbitals, thanks to Mimas' 2:3 inner Mean Motion Resonances

    NASA Astrophysics Data System (ADS)

    Crida, Aurelien; El Moutamid, Maryame

    2016-10-01

    Janus and Epimetheus orbit Saturn at 151461 km on average, on mutual horseshoe orbits with orbital separation 50 km, exchanging position every 4 years. This configuration is unique and intriguing : Lissauer et al. (1985) have shown that their orbital separation should converge to zero in about 20 Myrs only, and no satisfactory model for the origin of this co-orbital resonance exists yet.Charnoz et al. (2010) have shown that Janus and Epimetheus probably formed from the spreading of the rings beyond the Roche radius. Here, we show that this happened when Mimas' 2:3 Lindblad Resonance, which used to confine the rings, receded past the Roche radius. This first explains the gap in mass and distance between Janus and Mimas, which is unexpected in the pyramidal regime of the ring spreading model (Crida & Charnoz 2012). Furthermore, at this time, the two capture sites of Mimas's 2:3 Corotation Resonance were full of ring material. We suggest that as the two capture sites were brought beyond the Roche radius, the captured material agglomerated into two bodies of ~1015 kg on the exact same orbit. These bodies then migrated outwards together due to their interaction with the rings, in mutual horseshoe orbits. The rings then spawn new small satellites, eventually accreted by the proto-Janus and the proto-Epimetheus. This excites their orbital separation, leading to today's configuration.

  2. Real-time and label-free ring-resonator monitoring of solid-phase recombinase polymerase amplification.

    PubMed

    Sabaté del Río, Jonathan; Steylaerts, Tim; Henry, Olivier Y F; Bienstman, Peter; Stakenborg, Tim; Van Roy, Wim; O'Sullivan, Ciara K

    2015-11-15

    In this work we present the use of a silicon-on-insulator (SOI) chip featuring an array of 64 optical ring resonators used as refractive index sensors for real-time and label-free DNA detection. Single ring functionalisation was achieved using a click reaction after precise nanolitre spotting of specific hexynyl-terminated DNA capture probes to link to an azido-silanised chip surface. To demonstrate detectability using the ring resonators and to optimise conditions for solid-phase amplification, hybridisation between short 25-mer single stranded DNA (ssDNA) fragments and a complementary capture probe immobilised on the surface of the ring resonators was carried out and detected through the shift in the resonant wavelength. Using the optimised conditions demonstrated via the solid-phase hybridisation, a 144-bp double stranded DNA (dsDNA) was then detected directly using recombinase and polymerase proteins through on-chip target amplification and solid-phase elongation of immobilised forward primers on specific rings, at a constant temperature of 37°C and in less than 60min, achieving a limit of detection of 7.8·10(-13)M (6·10(5) copies in 50µL). The use of an automatic liquid handler injection instrument connected to an integrated resealable chip interface (RCI) allowed programmable multiple injection protocols. Air plugs between different solutions were introduced to prevent intermixing and a proportional-integral-derivative (PID) temperature controller minimised temperature based drifts.

  3. Microstrip superconducting quantum interference device radio-frequency amplifier: Scattering parameters and input coupling

    SciTech Connect

    Kinion, D; Clarke, J

    2008-01-24

    The scattering parameters of an amplifier based on a dc Superconducting QUantum Interference Device (SQUID) are directly measured at 4.2 K. The results can be described using an equivalent circuit model of the fundamental resonance of the microstrip resonator which forms the input of the amplifier. The circuit model is used to determine the series capacitance required for critical coupling of the microstrip to the input circuit.

  4. Tunable Room Temperature THz Sources Based on Nonlinear Mixing in a Hybrid Optical and THz Micro-Ring Resonator

    NASA Astrophysics Data System (ADS)

    Sinha, Raju; Karabiyik, Mustafa; Al-Amin, Chowdhury; Vabbina, Phani K.; Güney, Durdu Ö.; Pala, Nezih

    2015-03-01

    We propose and systematically investigate a novel tunable, compact room temperature terahertz (THz) source based on difference frequency generation in a hybrid optical and THz micro-ring resonator. We describe detailed design steps of the source capable of generating THz wave in 0.5-10 THz with a tunability resolution of 0.05 THz by using high second order optical susceptibility (χ(2)) in crystals and polymers. In order to enhance THz generation compared to bulk nonlinear material, we employ a nonlinear optical micro-ring resonator with high-Q resonant modes for infrared input waves. Another ring oscillator with the same outer radius underneath the nonlinear ring with an insulation of SiO2 layer supports the generated THz with resonant modes and out-couples them into a THz waveguide. The phase matching condition is satisfied by engineering both the optical and THz resonators with appropriate effective indices. We analytically estimate THz output power of the device by using practical values of susceptibility in available crystals and polymers. The proposed source can enable tunable, compact THz emitters, on-chip integrated spectrometers, inspire a broader use of THz sources and motivate many important potential THz applications in different fields.

  5. Tunable Room Temperature THz Sources Based on Nonlinear Mixing in a Hybrid Optical and THz Micro-Ring Resonator

    PubMed Central

    Sinha, Raju; Karabiyik, Mustafa; Al-Amin, Chowdhury; Vabbina, Phani K.; Güney, Durdu Ö.; Pala, Nezih

    2015-01-01

    We propose and systematically investigate a novel tunable, compact room temperature terahertz (THz) source based on difference frequency generation in a hybrid optical and THz micro-ring resonator. We describe detailed design steps of the source capable of generating THz wave in 0.5–10 THz with a tunability resolution of 0.05 THz by using high second order optical susceptibility (χ(2)) in crystals and polymers. In order to enhance THz generation compared to bulk nonlinear material, we employ a nonlinear optical micro-ring resonator with high-Q resonant modes for infrared input waves. Another ring oscillator with the same outer radius underneath the nonlinear ring with an insulation of SiO2 layer supports the generated THz with resonant modes and out-couples them into a THz waveguide. The phase matching condition is satisfied by engineering both the optical and THz resonators with appropriate effective indices. We analytically estimate THz output power of the device by using practical values of susceptibility in available crystals and polymers. The proposed source can enable tunable, compact THz emitters, on-chip integrated spectrometers, inspire a broader use of THz sources and motivate many important potential THz applications in different fields. PMID:25800287

  6. Planar ring-shaped phononic crystal anchoring boundaries for enhancing the quality factor of Lamb mode resonators

    NASA Astrophysics Data System (ADS)

    Binci, L.; Tu, C.; Zhu, H.; Lee, J. E.-Y.

    2016-11-01

    We report the use of planar ring-shaped phononic crystals (PnCs) as anchor boundaries of very-high-frequency band piezoelectric-on-silicon Lamb mode resonators for the purpose of enhancing their quality factor (Q). Here, we exploit the acoustic bandgap associated with the PnC anchoring boundaries to reduce acoustic energy leakage out of the micromechanical resonator. The proposed approach provides greater mechanical robustness (by merit of interlocking the cells in a matrix) and the possibility of electrical routing through the PnC cells. We experimentally show enhancements in Q by a factor of three using the proposed approach of hybridizing planar ring-shaped PnCs with micromechanical resonators. The effect of these PnCs on resonator Q is further corroborated by their effects in suppressing transmission when incorporated into a delay line.

  7. Characteristic impedance of microstrip lines

    NASA Technical Reports Server (NTRS)

    Bailey, M. C.; Deshpande, M. D.

    1989-01-01

    The dyadic Green's function for a current embedded in a grounded dielectric slab is used to analyze microstrip lines at millimeter wave frequencies. The dyadic Green's function accounts accurately for fringing fields and dielectric cover over the microstrip line. Using Rumsey's reaction concept, an expression for the characteristic impedance is obtained. The numerical results are compared with other reported results.

  8. Vertical split-ring resonator based anomalous beam steering with high extinction ratio

    PubMed Central

    Hsu, Wei-Lun; Wu, Pin Chieh; Chen, Jia-Wern; Chen, Ting-Yu; Cheng, Bo Han; Chen, Wei Ting; Huang, Yao-Wei; Liao, Chun Yen; Sun, Greg; Tsai, Din Ping

    2015-01-01

    Metasurfaces created artificially with metal nanostructures that are patterned on surfaces of different media have shown to possess “unusual” abilities to manipulate light. Limited by nanofabrication difficulties, so far most reported works have been based on 2D metal structures. We have recently developed an advanced e-beam process that allowed for the deposition of 3D nanostructures, namely vertical split-ring resonators (VSRRs), which opens up another degree of freedom in the metasurface design. Here we explore the functionality of beam steering with phase modulation by tuning only the vertical dimension of the VSRRs and show that anomalous steering reflection of a wide range of angles can be accomplished with high extinction ratio using the finite-difference-time-domain simulation. We also demonstrate that metasurfaces made of 3D VSRRs can be made with roughly half of the footprint compared to that of 2D nano-rods, enabling high density integration of metal nanostructures. PMID:26054048

  9. Vertical split-ring resonator based anomalous beam steering with high extinction ratio.

    PubMed

    Hsu, Wei-Lun; Wu, Pin Chieh; Chen, Jia-Wern; Chen, Ting-Yu; Cheng, Bo Han; Chen, Wei Ting; Huang, Yao-Wei; Liao, Chun Yen; Sun, Greg; Tsai, Din Ping

    2015-06-08

    Metasurfaces created artificially with metal nanostructures that are patterned on surfaces of different media have shown to possess "unusual" abilities to manipulate light. Limited by nanofabrication difficulties, so far most reported works have been based on 2D metal structures. We have recently developed an advanced e-beam process that allowed for the deposition of 3D nanostructures, namely vertical split-ring resonators (VSRRs), which opens up another degree of freedom in the metasurface design. Here we explore the functionality of beam steering with phase modulation by tuning only the vertical dimension of the VSRRs and show that anomalous steering reflection of a wide range of angles can be accomplished with high extinction ratio using the finite-difference-time-domain simulation. We also demonstrate that metasurfaces made of 3D VSRRs can be made with roughly half of the footprint compared to that of 2D nano-rods, enabling high density integration of metal nanostructures.

  10. Infrared cloaking based on the electric response of split ring resonators.

    PubMed

    Kanté, Boubacar; de Lustrac, André; Lourtioz, Jean-Michel; Burokur, Shah N

    2008-06-09

    Electromagnetic cloak was recently demonstrated in the microwave domain using a metamaterial structure made of metallic split ring resonators (SRR) arranged in a cylindrical geometry. The SRRs were designed to provide a magnetic response that varied in an appropriate manner with the radial coordinate. In the present work, we propose an electromagnetic cloak, which exploits the electric response of gold SRRs instead of their magnetic response. Numerical simulations performed at infrared frequencies (~100 THz) reveal low loss and weak impedance mismatch, thereby proving the interest in using SRRs as ???universal??? atoms in the design of metamaterials. We also show that SRRs can be ultimately replaced by simple cut wires for the construction of approximate electromagnetic cloaks whose dielectric permittivity is the only parameter varying with space coordinates.

  11. Asymmetric split-ring resonator-based biosensor for detection of label-free stress biomarkers

    NASA Astrophysics Data System (ADS)

    Lee, Hee-Jo; Lee, Jung-Hyun; Choi, Suji; Jang, Ik-Soon; Choi, Jong-Soon; Jung, Hyo-Il

    2013-07-01

    In this paper, an asymmetric split-ring resonator, metamaterial element, is presented as a biosensing transducer for detection of highly sensitive and label-free stress biomarkers. In particular, the two biomarkers, cortisol and α-amylase, are used for evaluating the sensitivity of the proposed biosensor. In case of cortisol detection, the competitive reaction between cortisol-bovine serum albumin and free cortisol is employed, while alpha-amylase is directly detected by its antigen-antibody reaction. From the experimental results, we find that the limit of detection and sensitivity of the proposed sensing device are about 1 ng/ml and 1.155 MHz/ng ml-1, respectively.

  12. Multi-channel silicon photonic receiver based on ring-resonators.

    PubMed

    Fang, Qing; Phang, Yu Ting; Tan, Chee Wei; Liow, Tsung-Yang; Yu, Ming Bin; Lo, Guo Qiang; Kwong, Dim Lee

    2010-06-21

    We demonstrated a high performance monolithically integrated multi-channel receiver fabricated on the SOI platform. This receiver is composed of a 1 x 8 Si-based ring-resonators filter and an array of high speed waveguided Ge-on-Si photodetectors. The optical channel spacing is about 1.5 nm. The responsivity of Ge-on-Si photodetector is about 1.0 A/W at the wavelength range of 1554 nm to 1564 nm. Each channel is capable of operating at a data rate of 20 Gbps, resulting in an aggregate data rate of 160 Gbps. At a BER of 1 x 10(-11), the receiver showed an optical input sensitivity of between -20 dBm and -21 dBm for each channel at 10 Gbps data rate.

  13. Four-channel optical add-drop multiplexer based on dual racetrack micro-ring resonators

    NASA Astrophysics Data System (ADS)

    Wu, Danning; Wu, Yuanda; Wang, Yue; An, Junming; Hu, Xiongwei

    2015-11-01

    In this paper we report on a four-channel optical add-drop multiplexer based on dual racetrack micro-ring resonators in submicron SOI rib waveguides. The free spectral range (FSR) is about 18.6 nm. The device can add/drop four optical channels in half C-band. When the device acts as an optical drop multiplexer, the channel spacing is about 1.5 nm, maximum extinction ratio is 23.75 dB, the minimum insertion loss 9.94 dB and the maximum adjacent channels crosstalk is -12.12 dB. When the device acts as an optical add multiplexer, the maximum extinction ratio is 28.72 dB and the minimum insertion loss 7.35 dB. The fabricated device has effectively and perfectly realized the signals upload and download.

  14. Photonic crystal ring resonator based optical filters for photonic integrated circuits

    SciTech Connect

    Robinson, S.

    2014-10-15

    In this paper, a two Dimensional (2D) Photonic Crystal Ring Resonator (PCRR) based optical Filters namely Add Drop Filter, Bandpass Filter, and Bandstop Filter are designed for Photonic Integrated Circuits (PICs). The normalized output response of the filters is obtained using 2D Finite Difference Time Domain (FDTD) method and the band diagram of periodic and non-periodic structure is attained by Plane Wave Expansion (PWE) method. The size of the device is minimized from a scale of few tens of millimeters to the order of micrometers. The overall size of the filters is around 11.4 μm × 11.4 μm which is highly suitable of photonic integrated circuits.

  15. Optimal second-harmonic generation in split-ring resonator arrays

    NASA Astrophysics Data System (ADS)

    Grynko, Yevgen; Meier, Torsten; Linden, Stefan; Niesler, Fabian B. P.; Wegener, Martin; Förstner, Jens

    2013-03-01

    Previous experimental measurements and numerical simulations give evidence of strong electric and magnetic field interaction between split-ring resonators in dense arrays. One can expect that such interactions have an influence on the second harmonic generation. We apply the Discontinuous Galerkin Time Domain method and the hydrodynamic Maxwell-Vlasov model to simulate the linear and nonlinear optical response from SRR arrays. The simulations show that dense placement of the constituent building blocks appears not always optimal and collective effects can lead to a significant suppression of the near fields at the fundamental frequency and, consequently, to the decrease of the SHG intensity. We demonstrate also the great role of the symmetry degree of the array layout which results in the variation of the SHG efficiency in range of two orders of magnitude.

  16. Photonic compressive sensing with a micro-ring-resonator-based microwave photonic filter

    NASA Astrophysics Data System (ADS)

    Chen, Ying; Ding, Yunhong; Zhu, Zhijing; Chi, Hao; Zheng, Shilie; Zhang, Xianmin; Jin, Xiaofeng; Galili, Michael; Yu, Xianbin

    2016-08-01

    A novel approach to realize photonic compressive sensing (CS) with a multi-tap microwave photonic filter is proposed and demonstrated. The system takes both advantages of CS and photonics to capture wideband sparse signals with sub-Nyquist sampling rate. The low-pass filtering function required in the CS is realized in a photonic way by using a frequency comb and a dispersive element. The frequency comb is realized by shaping an amplified spontaneous emission (ASE) source with an on-chip micro-ring resonator, which is beneficial to the integration of photonic CS. A proof-of-concept experiment for a two-tone signal acquisition with frequencies of 350 MHz and 1.25 GHz is experimentally demonstrated with a compression factor up to 16.

  17. On-chip modulation for rotating sensing of gyroscope based on ring resonator coupled with Mach-Zehnder interferometer.

    PubMed

    Zhang, Hao; Chen, Jiayang; Jin, Junjie; Lin, Jian; Zhao, Long; Bi, Zhuanfang; Huang, Anping; Xiao, Zhisong

    2016-01-22

    An improving structure for resonance optical gyro inserting a Mach-Zehnder Interferomete (MZI) into coupler region between ring resonator and straight waveguide was proposed. The different reference phase shift parameters in the MZI arms are tunable by thermo-optic effect and can be optimized at every rotation angular rate point without additional phase bias. Four optimum paths are formed to make the gyroscope to work always at the highest sensitivity.

  18. Demonstration of composite signal enhancement from surface enhanced Raman spectroscopy in a liquid core optical ring resonator

    NASA Astrophysics Data System (ADS)

    White, Ian M.; Gohring, John; Fan, Xudong

    2007-09-01

    Surface enhanced Raman spectroscopy (SERS) utilizing silver colloids for localized plasmonic enhancement has been heavily researched due to its tremendous increase in the Raman signal of bio/chemical molecules. We demonstrate further enhancement by multiplying the SERS effect by the resonant enhancement of a ring resonator microcavity. The liquid core optical ring resonator (LCORR) offers a high-performance and practical design to obtain this composite enhancement for bio/chemical molecule detection. The LCORR integrates an array of optical ring resonators into a capillary-based microfluidic channel to form a novel bio/chemical sensing platform. The circular cross-section of the glass capillary acts as an optical ring resonator, with the evanescent field of the resonant light interacting with the sample passing through the capillary. The LCORR has already been well-studied for applications in label free biomolecule sensing. In this work, we utilize a silver colloid solution inside the capillary to perform SERS-based detection. In contrast to a typical SERS system where the incident light interacts with the colloid and target molecules only once, in the LCORR system, the tightly confined light resonates around the capillary wall, repeatedly interacting with the SERS system. Our experimental results show the increased enhancement due to the composite effect of the cavity resonance and the localized plasmonic effect of the nanoparticles inside the cavity. We have achieved detection of 3.3 nM R6G inside the LCORR. In addition to the excellent sensitivity, this detection system represents an advancement in the development of practical SERS bio/chemical sensors due to the arrayed nature of the sensors combined with the integrated microfluidics of the LCORR.

  19. On-chip modulation for rotating sensing of gyroscope based on ring resonator coupled with Mach-Zehnder interferometer

    PubMed Central

    Zhang, Hao; Chen, Jiayang; Jin, Junjie; Lin, Jian; Zhao, Long; Bi, Zhuanfang; Huang, Anping; Xiao, Zhisong

    2016-01-01

    An improving structure for resonance optical gyro inserting a Mach-Zehnder Interferomete (MZI) into coupler region between ring resonator and straight waveguide was proposed. The different reference phase shift parameters in the MZI arms are tunable by thermo-optic effect and can be optimized at every rotation angular rate point without additional phase bias. Four optimum paths are formed to make the gyroscope to work always at the highest sensitivity. PMID:26796334

  20. How to remove the spurious resonances from ring polymer molecular dynamics

    SciTech Connect

    Rossi, Mariana; Manolopoulos, David E.; Ceriotti, Michele

    2014-06-21

    Two of the most successful methods that are presently available for simulating the quantum dynamics of condensed phase systems are centroid molecular dynamics (CMD) and ring polymer molecular dynamics (RPMD). Despite their conceptual differences, practical implementations of these methods differ in just two respects: the choice of the Parrinello-Rahman mass matrix and whether or not a thermostat is applied to the internal modes of the ring polymer during the dynamics. Here, we explore a method which is halfway between the two approximations: we keep the path integral bead masses equal to the physical particle masses but attach a Langevin thermostat to the internal modes of the ring polymer during the dynamics. We justify this by showing analytically that the inclusion of an internal mode thermostat does not affect any of the established features of RPMD: thermostatted RPMD is equally valid with respect to everything that has actually been proven about the method as RPMD itself. In particular, because of the choice of bead masses, the resulting method is still optimum in the short-time limit, and the transition state approximation to its reaction rate theory remains closely related to the semiclassical instanton approximation in the deep quantum tunneling regime. In effect, there is a continuous family of methods with these properties, parameterised by the strength of the Langevin friction. Here, we explore numerically how the approximation to quantum dynamics depends on this friction, with a particular emphasis on vibrational spectroscopy. We find that a broad range of frictions approaching optimal damping give similar results, and that these results are immune to both the resonance problem of RPMD and the curvature problem of CMD.

  1. Small-Scale Gaps Near Resonance Locations in Saturn's A Ring

    NASA Astrophysics Data System (ADS)

    Brown, Zarah; Rehnberg, Morgan; Esposito, Larry W.; Albers, Nicole

    2016-10-01

    High-resolution Cassini stellar occultation data has allowed for the direct investigation of self-gravity wakes and other disturbances in ring-particle density that cause an observed azimuthal brightness asymmetry. Using Cassini UVIS occultation data collected between May 19 2005 and June 2 2013 (Cassini revolutions 8 - 191), we investigate small-scale gaps in Saturn's A ring, which may form between adjacent self-gravity wakes. Factors that affect the radial width and observation frequency of tenuous gap regions are investigated, including a discussion of how various occultation parameters alter gap detection. Here we show that gaps are wider within the wave trains than in surrounding unperturbed regions of the following inner Lindblad resonances (ILR): Janus 4:3, Janus 5:4, Janus 6:5 and Mimas 5:3. These trends are compared to those found at the Mimas 5:3 bending wave. Radial gap width and number density are compared in the peak and trough regions of the ILR wave trains.

  2. Design of multi-band microstrip polygonal contour filter for microwaves

    NASA Astrophysics Data System (ADS)

    Gavriloaia, Bogdan; Vizireanu, Radu; Fratu, Octavian; Halunga, Simona; Barca, Cristian; Mara, Constantin

    2016-12-01

    The rapid growth of wireless communications requires a new generation of multifunction devices operating simultaneously under multiple communication standards, in several bands, small, robust and low cost. Microstrip technology can provide these features. An original topological structure is presented in this paper. It integrates several microstrip lines and lumped components in an asymmetric network, and has three ports. A lot of resonance frequencies occur as a result of combination between normal and degenerate propagation modes. Dual-band and three-bands can be selected, depending on the ports used. The originality of this work is to investigate a pentagonal pattern microstrip and introduces two types of perturbations given by two capacitors and a microstrip line section between the corners of the pentagon. The electric field patterns and insertion loss are calculated and provide the possibility of implementing microstrip and larger flexibility for choosing different frequency bands for wireless applications.

  3. MEMS-based electrostatically tunable microstrip patch antenna using flexible polyimide film

    NASA Astrophysics Data System (ADS)

    Goteti, Raghav Venkat; Ramadoss, Ramesh

    2005-05-01

    This paper reports a MEMS-based electrostatically tunable microstrip patch antenna fabricated using printed circuit processing techniques. The microstrip patch is patterned on the top side of the flexible kapton polyimide film, which is suspended above the fixed ground plane using a spacer. The air gap between the microstrip patch and the ground plane is decreased by applying a DC bias voltage between the patch and the ground plane. A decrease in air gap increases the effective permittivity of the antenna resulting in a downward shift in the resonant frequency. The microstrip patch is excited by a slot in the ground plane, which is inductively coupled by a coplanar waveguide (CPW) feed line. A 6 mm x 6 mm microstrip patch antenna tunable from 18.34 GHz at 0 V to 17.95 GHz at 268 V (with a tuning range of 390 MHz) is discussed.

  4. Design of a loop resonator with a split-ring-resonator (SRR) for a human-body coil in 3 T MRI systems

    NASA Astrophysics Data System (ADS)

    Son, Hyeok Woo; Cho, Young Ki; Kim, Byung Mun; Back, Hyun Man; Yoo, Hyoungsuk

    2016-04-01

    A new radio-frequency (RF) resonator for Nuclear Magnetic Resonance (NMR) imaging at clinical magnetic resonance imaging (MRI) systems is proposed in this paper. An approach based on the effects of the properties of metamaterials in split-ring resonators (SRRs) is used to design a new loop resonator with a SRR for NMR imaging. This loop resonator with a SRR is designed for NMR imaging at 3 T MRI systems. The 3D electromagnetic simulation was used to optimize the design of the proposed RF resonator and analyze it's performance at 3 T MRI systems. The proposed RF resonator provides strong penetrating magnetic fields at the center of the human phantom model, approximately 10%, as compared to the traditional loop-type RF resonator used for NMR imaging at clinical MRI systems. We also designed an 8-channel body coil for human-body NMR imaging by using the proposed loop resonator with a SRR. This body coil also produces more homogeneous and highly penetrating magnetic fields into the human phantom model.

  5. Study of photon–magnon coupling in a YIG-film split-ring resonant system

    SciTech Connect

    Bhoi, B.; Aiyar, R.; Cliff, T.; Maksymov, I. S.; Kostylev, M.; Venkataramani, N.; Prasad, S.; Stamps, R. L.

    2014-12-28

    By using the stripline Microwave Vector–Network Analyser Ferromagnetic Resonance and Time Domain spectroscopy techniques, we study a strong coupling regime of magnons to microwave photons in the planar geometry of a lithographically formed split-ring resonator (SRR) loaded by a single-crystal epitaxial yttrium–iron–garnet (YIG) film. Strong anti-crossing of the photon modes of SRR and of the magnon modes of the YIG film is observed in the applied-magnetic-field resolved measurements. The coupling strength extracted from the experimental data reaches 9% at 3 GHz. Theoretically, we propose an equivalent circuit model of the SRR loaded by a magnetic film. This model follows from the results of our numerical simulations of the microwave field structure of the SRR and of the magnetisation dynamics in the YIG film driven by the microwave currents in the SRR. The results obtained with the equivalent-circuit model are in good agreement with the experiment. This model provides a simple physical explanation of the process of mode anti-crossing. Our findings are important for future applications in microwave quantum photonic devices as well as in nonlinear and magnetically tuneable metamaterials exploiting the strong coupling of magnons to microwave photons.

  6. Ultra-high-Q thin-silicon nitride strip-loaded ring resonators.

    PubMed

    Stefan, L; Bernard, M; Guider, R; Pucker, G; Pavesi, L; Ghulinyan, M

    2015-07-15

    We report on the design, fabrication, and characterization of thin Si3N4 ultra-high-quality (UHQ) factor ring resonators monolithically integrated on a silicon chip. The devices are based on a strip-loaded configuration and operate at both near-infrared (NIR) and third-telecom wavelengths. This approach allows us to use a guiding Si3N4 core that is one order of magnitude thinner than what has been reported in the past for obtaining similar device performances. Our strip-loaded devices benefit from the absence of physically etched lateral boundaries to show minute light scattering and, therefore, reducing significantly scattering-related losses. Consequently, UHQs of 3.7×10(6) in the NIR and high-quality factors of up to 9×10(5) in the C-band were measured for the guiding material thickness of 80 nm and 115 nm, respectively. These first results are subject to further improvements that may allow employing strip-loaded resonators in nonlinear frequency conversion or quantum computing schemes within the desired spectral range provided by the material transparency.

  7. An advanced EPR stopped-flow apparatus based on a dielectric ring resonator

    NASA Astrophysics Data System (ADS)

    Lassmann, Günter; Schmidt, Peter Paul; Lubitz, Wolfgang

    2005-02-01

    A novel EPR stopped-flow accessory is described which allows time-dependent cw-EPR measurements of rate constants of reactions involving paramagnetic species after rapid mixing of two liquid reagents. The EPR stopped-flow design represents a state-of-the-art, computer controlled fluid driving system, a miniresonant EPR structure with an integrated small ball mixer, and a stopping valve. The X-band EPR detection system is an improved version of that reported by Sienkiewicz et al. [Rev. Sci. Instr. 65 (1994) 68], and utilizes a resonator with two stacked ceramic dielectric rings separated by a variable spacer. The resonator with the mode TE( H) 011 is tailored particularly for conditions of fast flowing and rapidly stopped aqueous solutions, and for a high time resolution. The short distance between the ball mixer and the small EPR active volume (1.8 μl) yields a measured dead time of 330 μs. A compact assembly of all parts results in minimization of disturbing microphonics. The computer controlled driving system from BioLogic with two independent stepping motors was optimized for EPR stopped-flow with a hard-stop valve. Performance tests on the EPR spectrometer ESP 300E from BRUKER using redox reactions of nitroxide radicals revealed the EPR stopped-flow accessory as an advanced, versatile, and reliable instrument with high reproducibility.

  8. Efficient Radiation by Electrically Small Antennas made of Coupled Split-ring Resonators

    PubMed Central

    Peng, Liang; Chen, Peiwei; Wu, Aiting; Wang, Gaofeng

    2016-01-01

    In this paper, coupled split-ring resonators (SRRs) are used to construct the electrically small antennas. We show that through strong magnetic coupling, the coupled SRRs composite can oscillate at a wavelength much larger than its total size. Due to its magnetic dipole feature, the coupled SRRs composite allows the electromagnetic (EM) power to radiate and hence forms the electrically small antenna (ESA). Because of the high-Q resonance, the ESA could be easily matched to the driving circuit in the microwave region, through mutual induction approach. We also demonstrate that the radiation efficiency of such ESAs can be drastically improved if the current distribution on individual SRRs is similar, which is achievable by carefully designing the ESAs. From our simulations and experimental measurements, the ESAs’ radiation efficiency can reach up to 41%, with relative footprint of 0.05λ0 × 0.05λ0. Our approach would be an effective way to realize ESAs with high efficiency, which can be implemented on chip through the standard planar lithography. PMID:27630076

  9. A Microwave Ring-Resonator Sensor for Non-Invasive Assessment of Meat Aging.

    PubMed

    Jilnai, Muhammad Taha; Wen, Wong Peng; Cheong, Lee Yen; ur Rehman, Muhammad Zaka

    2016-01-20

    The assessment of moisture loss from meat during the aging period is a critical issue for the meat industry. In this article, a non-invasive microwave ring-resonator sensor is presented to evaluate the moisture content, or more precisely water holding capacity (WHC) of broiler meat over a four-week period. The developed sensor has shown significant changes in its resonance frequency and return loss due to reduction in WHC in the studied duration. The obtained results are also confirmed by physical measurements. Further, these results are evaluated using the Fricke model, which provides a good fit for electric circuit components in biological tissue. Significant changes were observed in membrane integrity, where the corresponding capacitance decreases 30% in the early aging (0D-7D) period. Similarly, the losses associated with intracellular and extracellular fluids exhibit changed up to 42% and 53%, respectively. Ultimately, empirical polynomial models are developed to predict the electrical component values for a better understanding of aging effects. The measured and calculated values are found to be in good agreement.

  10. A Microwave Ring-Resonator Sensor for Non-Invasive Assessment of Meat Aging

    PubMed Central

    Jilani, Muhammad Taha; Wen, Wong Peng; Cheong, Lee Yen; ur Rehman, Muhammad Zaka

    2016-01-01

    The assessment of moisture loss from meat during the aging period is a critical issue for the meat industry. In this article, a non-invasive microwave ring-resonator sensor is presented to evaluate the moisture content, or more precisely water holding capacity (WHC) of broiler meat over a four-week period. The developed sensor has shown significant changes in its resonance frequency and return loss due to reduction in WHC in the studied duration. The obtained results are also confirmed by physical measurements. Further, these results are evaluated using the Fricke model, which provides a good fit for electric circuit components in biological tissue. Significant changes were observed in membrane integrity, where the corresponding capacitance decreases 30% in the early aging (0D-7D) period. Similarly, the losses associated with intracellular and extracellular fluids exhibit changed up to 42% and 53%, respectively. Ultimately, empirical polynomial models are developed to predict the electrical component values for a better understanding of aging effects. The measured and calculated values are found to be in good agreement. PMID:26805828

  11. Qubit entanglement between ring-resonator photon-pair sources on a silicon chip

    PubMed Central

    Silverstone, J. W.; Santagati, R.; Bonneau, D.; Strain, M. J.; Sorel, M.; O'Brien, J. L.; Thompson, M. G.

    2015-01-01

    Entanglement—one of the most delicate phenomena in nature—is an essential resource for quantum information applications. Scalable photonic quantum devices must generate and control qubit entanglement on-chip, where quantum information is naturally encoded in photon path. Here we report a silicon photonic chip that uses resonant-enhanced photon-pair sources, spectral demultiplexers and reconfigurable optics to generate a path-entangled two-qubit state and analyse its entanglement. We show that ring-resonator-based spontaneous four-wave mixing photon-pair sources can be made highly indistinguishable and that their spectral correlations are small. We use on-chip frequency demultiplexers and reconfigurable optics to perform both quantum state tomography and the strict Bell-CHSH test, both of which confirm a high level of on-chip entanglement. This work demonstrates the integration of high-performance components that will be essential for building quantum devices and systems to harness photonic entanglement on the large scale. PMID:26245267

  12. Polycrystalline silicon ring resonator photodiodes in a bulk complementary metal-oxide-semiconductor process.

    PubMed

    Mehta, Karan K; Orcutt, Jason S; Shainline, Jeffrey M; Tehar-Zahav, Ofer; Sternberg, Zvi; Meade, Roy; Popović, Miloš A; Ram, Rajeev J

    2014-02-15

    We present measurements on resonant photodetectors utilizing sub-bandgap absorption in polycrystalline silicon ring resonators, in which light is localized in the intrinsic region of a p+/p/i/n/n+ diode. The devices, operating both at λ=1280 and λ=1550  nm and fabricated in a complementary metal-oxide-semiconductor (CMOS) dynamic random-access memory emulation process, exhibit detection quantum efficiencies around 20% and few-gigahertz response bandwidths. We observe this performance at low reverse biases in the range of a few volts and in devices with dark currents below 50 pA at 10 V. These results demonstrate that such photodetector behavior, previously reported by Preston et al. [Opt. Lett. 36, 52 (2011)], is achievable in bulk CMOS processes, with significant improvements with respect to the previous work in quantum efficiency, dark current, linearity, bandwidth, and operating bias due to additional midlevel doping implants and different material deposition. The present work thus offers a robust realization of a fully CMOS-fabricated all-silicon photodetector functional across a wide wavelength range.

  13. Gold asymmetric-split ring resonators (A-SRRs) for proteins sensing

    NASA Astrophysics Data System (ADS)

    Paul, Jharna; De La Rue, Richard M.; Johnson, Nigel P.

    2016-04-01

    In this paper, gold asymmetric-split ring resonators (A-SRRs) are used for proteins sensing in the mid-infrared (IR) spectral region. Self-assembled monolayers (SAMs) of octadecanethiol (ODT) in ethanolic solution were deposited on the resonator surfaces to immobilise protein molecules for their detection. Different diameters ASRRs were fabricated on zinc selenide (ZnSe) substrates using electron-beam lithography technique. Their plasmonic responses appear in the mid-IR spectral region and match with the vibrational responses of many organic molecules. After the formation of SAMs layer, one sample was immersed in bovine serum albumin (BSA) solution for proteins adsorption while other sample was immersed in hydroxyl terminated hexa-ethylene glycol (EG6-OH) solution to modify SAMs surfaces to resist immobilisation of proteins. The vibrational responses of these organic molecules, all samples were excited using an incident broadband mid-IR light source and their reflectance spectra were measured at normal incidence using a microscope coupled Fourier Transform Infrared (FTIR) spectrometer. This study highlights the capability of plasmonic structures (A-SRRs) fabricated on transparent and high refractive index ZnSe substrates allows the detection of BSA proteins with enhanced detection in the mid-IR spectral range, demonstrating their potential for a wide range of sensing applications, e.g. in biomedical engineering and food industries.

  14. Active noise control using noise source having adaptive resonant frequency tuning through variable ring loading

    NASA Technical Reports Server (NTRS)

    Pla, Frederic G. (Inventor); Rajiyah, Harindra (Inventor); Renshaw, Anthony A. (Inventor); Hedeen, Robert A. (Inventor)

    1995-01-01

    A noise source for an aircraft engine active noise cancellation system in which the resonant frequency of noise radiating structure is tuned to permit noise cancellation over a wide range of frequencies. The resonant frequency of the noise radiating structure is tuned by a plurality of drivers arranged to contact the noise radiating structure. Excitation of the drivers causes expansion or contraction of the drivers, thereby varying the edge loading applied to the noise radiating structure. The drivers are actuated by a controller which receives input of a feedback signal proportional to displacement of the noise radiating element and a signal corresponding to the blade passage frequency of the engine's fan. In response, the controller determines a control signal which is sent to the drivers, causing them to expand or contract. The noise radiating structure may be either the outer shroud of the engine or a ring mounted flush with an inner wall of the shroud or disposed in the interior of the shroud.

  15. Detection of HER2 breast cancer biomarker using the optofluidic ring resonator biosensor

    NASA Astrophysics Data System (ADS)

    Gohring, John T.; Dale, Paul S.; Fan, Xudong

    2010-04-01

    In this work, we describe a novel approach for detecting the HER2/neu extra-cellular domain (ECD) protein in human serum samples using the opto-fluidic ring resonator (OFRR). OFRR sensing technology that incorporates microfluidics and optical sensing methods to achieve rapid label free detection in a small and low cost platform. In this study, HER2 proteins were spiked in PBS running buffer and serum at varying concentrations. Concentrations of the HER2 protein were adjusted in serum to levels typical of breast cancer patients that show over-expression of this particular beast cancer biomarker. The OFRR was modified with a biologically functional layer to efficiently capture the HER2 biomarker and produce a sensing signal through interaction with the evanescent field of the optical resonator. Results show effective capture of HER2 at medically relevant concentrations in serum and was achieved for concentrations as low as 13 ng/mL and ranged to above 100 ng/mL. This work will lead to a device that can be used as a tool for monitoring disease progression in a low cost sensing setup.

  16. Efficient Radiation by Electrically Small Antennas made of Coupled Split-ring Resonators

    NASA Astrophysics Data System (ADS)

    Peng, Liang; Chen, Peiwei; Wu, Aiting; Wang, Gaofeng

    2016-09-01

    In this paper, coupled split-ring resonators (SRRs) are used to construct the electrically small antennas. We show that through strong magnetic coupling, the coupled SRRs composite can oscillate at a wavelength much larger than its total size. Due to its magnetic dipole feature, the coupled SRRs composite allows the electromagnetic (EM) power to radiate and hence forms the electrically small antenna (ESA). Because of the high-Q resonance, the ESA could be easily matched to the driving circuit in the microwave region, through mutual induction approach. We also demonstrate that the radiation efficiency of such ESAs can be drastically improved if the current distribution on individual SRRs is similar, which is achievable by carefully designing the ESAs. From our simulations and experimental measurements, the ESAs’ radiation efficiency can reach up to 41%, with relative footprint of 0.05λ0 × 0.05λ0. Our approach would be an effective way to realize ESAs with high efficiency, which can be implemented on chip through the standard planar lithography.

  17. Series-fed circularly polarized microstrip antennas with broad bandwidth

    NASA Astrophysics Data System (ADS)

    Mao, Shau-Gang; Chen, Shiou-Li; Yeh, Jen-Chun; Lin, Tien-Min

    2007-08-01

    A new series-fed circularly polarized antenna (SFCPA) in microstrip configuration, which consists of a traveling-wave-type crank-line antenna (CLA) and a resonant-type square-ring slot antenna (SRSA), is developed. Unlike the conventional crank-line (CL) antenna array with an open end or a resistive load, the proposed SFCPA uses the SRSA at the termination of the CLA and thus exhibits not only a broad circularly polarized (CP) bandwidth but also a large antenna gain. The characteristics of the SFCPA, including the leaky-wave radiation and the circular polarization, are examined in terms of the dispersion diagram and the current distribution. The SFCPA with the two-cell CLA and the terminated SRSA is fabricated and measured to demonstrate the 10-dB return loss and 3-dB axial ratio (AR) bandwidths of 34.3% and 30.5%, respectively. The frequency-scanning radiation patterns with a 5-7 dBi antenna gain are also presented in the operating band.

  18. The simulation and improved design of tunable channel drop filter using hexagonal photonic crystal ring resonator

    SciTech Connect

    Chhipa, Mayur Kumar

    2014-10-15

    In this paper, we have proposed a new design of tunable two dimensional (2D) photonic crystal (PhC) channel drop filter (CDF) using ring resonators. The increasing interest in photonic integrated circuits (PIC's) and the increasing use of all-optical fiber networks as backbones for global communication systems have been based in large part on the extremely wide optical transmission bandwidth provided by dielectric materials. Based on the analysis we present novel photonic crystal channel drop filters. Simulations demonstrate that these filters exhibit ideal transfer characteristics. Channel dropping filters (CDF's) that access one channel of a wavelength division multiplexed (WDM) signal while leaving other channels undisturbed are essential components of PIC's and optical communication systems. In this paper we have investigated such parameters which have an effect on resonant wavelength in this Channel Drop Filter, such as dielectric constant of inner, coupling, adjacent and whole rods of the structure. The dimensions of these structures are taken as 20a×19a and the area of the proposed structure is about 125.6μm{sup 2}; therefore this structure can be used in the future photonic integrated circuits. While using this design the dropping efficiency at the resonance of single ring are 100%. The spectrum of the power transmission is obtained with finite difference time domain (FDTD) method. FDTD method is the most famous method for PhC analysis. In this paper the dielectric rods have a dielectric constant of 10.65, so the refractive index is 3.26 and radius r=0.213a is located in air, where a is a lattice constant. In this we have used five scatter rods for obtaining more coupling efficiency; radius of scatter rods is set to 0.215a. The proposed structure is simulated with OptiFDTD.v.8.0 software, the different dielectric constant of rods equal to ε{sub r}−0.4, ε{sub r} and ε{sub r}+0.4 at wavelength of 1570 nm.

  19. Multiplicity of transmission coefficients in photonic crystal and split ring resonator waveguides with Kerr nonlinear impurities

    NASA Astrophysics Data System (ADS)

    Rai, Buddhi; McGurn, Arthur R.

    2015-02-01

    Photonic crystal and split ring resonator (SRR) metamaterial waveguides with Kerr nonlinear dielectric impurities are studied. The transmission coefficients for two guided modes of different frequencies scattering from the Kerr impurities are computed. The systems are shown to exhibit multiple transmission coefficient solutions arising from the Kerr nonlinearity. Multiple transmission coefficients occur when different input intensities into a waveguide result in the same transmitted output intensities past its nonlinear impurities. (In the case of a single incident guided mode the multiplicity of transmission coefficients is known as optical bistability.) The analytical conditions under which the transmission coefficients are single and multiple valued are determined, and specific examples of both single and multiple valued transmission coefficient scattering are presented. Both photonic crystal and split ring resonator systems are studied as the Kerr nonlinearity enters the photonic crystal and SRR systems in different ways. This allows for an interesting comparison of the differences in behaviors of these two types of system which are described by distinctly different mathematical structures. Both the photonic crystal and SRR models used in the calculations are based on a difference equation approach to the system dynamics. The difference equation approach has been extensively employed in previous papers to model the basic properties of these systems. The paper is a continuation of work on the optical bistability of single guided modes interacting with Kerr impurities in photonic crystals originally considered by McGurn [Chaos 13, 754 (2003), 10.1063/1.1568691] and work on the resonant scattering from Kerr impurities in photonic crystal waveguides considered by McGurn [J. Phys.: Condens. Matter 16, S5243 (2004), 10.1088/0953-8984/16/44/021]. It generalizes this work making the extension to the more complex interaction of two guided modes at different frequencies

  20. Lab-on-a-chip bio/chemical sensing system based on the liquid core optical ring resonator

    NASA Astrophysics Data System (ADS)

    White, Ian M.; Suter, Jonathan D.; Zhu, Hongying; Oveys, Hesam; Brewington, Lee; Gohring, John; Fan, Xudong

    2007-04-01

    The liquid core optical ring resonator (LCORR) sensor is a newly developed capillary-based ring resonator that integrates microfluidics with photonic sensing technology. The circular cross-section of the capillary forms a ring resonator that supports whispering gallery modes (WGM), which interact with the sample as it passes through the capillary. As in previous ring resonator sensor implementations, the interaction between the WGM evanescent field and the sample enables label-free detection. With a prototype of an LCORR sensor, we have achieved a refractive index detection limit of 10-6 RIU and a detection limit for protein of 2 pg/mm2. Several engineering developments have been accomplished as well, including a thermal noise characterization, a thermal stabilization implementation, integration of the LCORR with a planar waveguide array, and electro-kinetic sample delivery. In the near future, the LCORR will be integrated into a dense 2-dimensional sensing array by integrating multiple capillaries with a chip-based waveguide array. This lab-on-a-chip sensing system will have a number of applications, including environmental sensing for defense purposes, disease diagnostics for medical purposes, and as a lab tool for analytical chemistry and molecular analysis.

  1. Beam position controlling method for 3D optical system and its application in non-planar ring resonators.

    PubMed

    Yuan, Jie; Chen, Meixiong; Long, Xingwu; Tan, Yanyang; Kang, Zhenglong; Li, Yingying

    2012-08-13

    A novel theoretical beam position controlling method for 3D optical system has been proposed in this paper. Non-planar ring resonator, which is a typical 3D optical system, has been chosen as an example to show its application. To the best of our knowledge, the generalized ray matrices, augmented 5 × 5 ray matrices for paraxial dielectric interface transmission and paraxial optical-wedge transmission, and their detailed deducing process have been proposed in this paper for the first time. By utilizing the novel coordinate system for Gaussian beam reflection and the generalized ray matrix of paraxial optical-wedge transmission, the rules and some novel results of the optical-axis perturbations of non-planar ring resonators have been obtained. Wedge angle-induced mismatching errors of non-planar ring resonators have been found out and two experimental beam position controlling methods to effectively eliminate the wedge angle-induced mismatching errors have been proposed. All those results have been confirmed by related alignment experiments and the experimental results have been described with diagrammatic representation. These findings are important to the beam control, cavity design, and cavity alignment of high precision non-planar ring laser gyroscopes. Those generalized ray matrices and their deducing methods are valuable for ray analysis of various kinds of paraxial optical-elements and resonators. This novel theoretical beam position controlling method for 3D optical system is valuable for the controlling of various kinds of 3D optical systems.

  2. A Cryogenic Waveguide Mount for Microstrip Circuit and Material Characterization

    NASA Technical Reports Server (NTRS)

    U-yen, Kongpop; Brown, Ari D.; Moseley, Samuel H.; Noroozian, Omid; Wollack, Edward J.

    2016-01-01

    A waveguide split-block fixture used in the characterization of thin-film superconducting planar circuitry at millimeter wavelengths is described in detail. The test fixture is realized from a pair of mode converters, which transition from rectangular-waveguide to on-chip microstrip-line signal propagation via a stepped ridge-guide impedance transformer. The observed performance of the W-band package at 4.2K has a maximum in-band transmission ripple of 2dB between 1.53 and 1.89 times the waveguide cutoff frequency. This metrology approach enables the characterization of superconducting microstrip test structures as a function temperature and frequency. The limitations of the method are discussed and representative data for superconducting Nb and NbTiN thin film microstrip resonators on single-crystal Si dielectric substrates are presented.

  3. Quasi-phase-matched second harmonic generation in silicon nitride ring resonators controlled by static electric field.

    PubMed

    de Oliveira, Rafael E P; de Matos, Christiano J S

    2013-12-30

    Actively-controlled second harmonic generation in a silicon nitride ring resonator is proposed and simulated. The ring was designed to resonate at both pump and second harmonic wavelengths and quasi-phase-matched frequency conversion is induced by a periodic static electric field generated by voltage applied to electrodes arranged along the ring. Nonlinear propagation simulations were undertaken and an efficiency of -21.67 dB was calculated for 60 mW of pump power at 1550 nm and for a 30V applied voltage, which compares favorably with demonstrated all-optical second harmonic generation in integrated microresonators. Transient effects were also evaluated. The proposed design can be exploited for the construction of electro-optical devices based on nonlinear effects in CMOS compatible circuits.

  4. Ultra-compact microwave filters using kinetic inductance microstrip

    SciTech Connect

    Pond, J.M.; Carroll, K.R.; Cukauskas, E.J. )

    1991-03-01

    This paper reports on multi-pole microwave filters designed and fabricated using microstrip transmission line sections which consist of two very thin films of sputtered niobium nitride (NbN) separated by another very thin film of sputtered Si. Since the thicknesses of all three films are much less than the superconducting penetration depth, the kinetic inductance is significantly greater than the magnetic inductance. As a result, the phase velocity of a microstrip transmission line is much less than the free space speed of light. Since resonant structures are reduced in size proportionately, the size and weight of microstrip circuits can be greatly reduced. Prototype filters consisting of four open circuit half-wavelength microstrip stubs separated by full-wavelength microstrip sections have been measured. The circuits are connected to 34 mil diameter coaxial cable via an intermediate coplanar waveguide section. Passbands of 4 GHz separated by 3 GHz reject bands have been measured in a structure which occupies less than 0.5 cm{sup 2} including the coplanar waveguide transitions. Higher-order passbands, although possessing an increased insertion loss, maintain filter passband characteristics through 20.0 GHz.

  5. Electro-optic switching based on a waveguide-ring resonator made of dielectric-loaded graphene plasmon waveguides

    NASA Astrophysics Data System (ADS)

    Qi, Zhe; Zhu, Zhi Hong; Xu, Wei; Zhang, Jian Fa; Cai Guo, Chu; Liu, Ken; Yuan, Xiao Dong; Qiao Qin, Shi

    2016-09-01

    We numerically demonstrate that electro-optic switching in the mid-infrared range can be realized using a waveguide-ring resonator made of dielectric-loaded graphene plasmon waveguides (DLGPWs). The numerical results are in good agreement with the results of physical analysis. The switching mechanism is based on dynamic modification of the resonant wavelengths of the ring resonator, achieved by varying the Fermi energy of a graphene sheet. The results reveal that a switching ratio of ∼24 dB can be achieved with only a 0.01 eV change in the Fermi energy. Such electrically controlled switching operation may find use in actively tunable integrated photonic circuits.

  6. Ultra-high sensitivity optical biosensor based on Vernier effect in triangular ring resonators (TRRs) with SPR

    NASA Astrophysics Data System (ADS)

    Kim, Tae-Ryong; Kim, Hong-Seung; Li, Jun; Oh, Geum-Yoon; Kim, Doo-Gun; Choi, Young-Wan

    2015-03-01

    In this paper, surface plasmon resonance triangular ring resonator (SPR-TRR) Vernier structure based on InP is simulated for index variation from 1.33 to 1.35. Sensing area of SPR-TRR is achieved to make an ultra-compact SPR mirror by deposition of Au film layer which is designed to deposit on vertex of TRR. The possibility of mass production is shown by a deposition of SPR mirror on the triangular ring resonator (TRR). Also, the sensitivity enhancement of an envelope signal for Vernier effect is confirmed by FDTD simulation compared to SPR-TRR. As simulation results, the sensitivity is enhanced 20 nm / RIU to 480 nm / RIU. Thus, SPR-TRR Vernier structure is used for a biosensor to enhance the sensitivity of biosensor.

  7. A new model for broadband waveguide-to-microstrip transition design

    NASA Technical Reports Server (NTRS)

    Ponchak, George E.; Downey, Alan N.

    1988-01-01

    A new model is presented which permits the prediction of the resonant frequencies created by antipodal finline waveguide to microstrip transitions. The transition is modeled as a tapered transmission line in series with an infinite set of coupled resonant circuits. The resonant circuits are modeled as simple microwave resonant cavities of which the resonant frequencies are easily determined. The model is developed and the resonant frequencies determined for several different transitions. Experimental results are given to confirm the models.

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

    NASA Astrophysics Data System (ADS)

    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.

  9. Dielectric loss in microstrip lines

    NASA Technical Reports Server (NTRS)

    Simpson, T. L.; Tseng, B.

    1976-01-01

    A technique is presented for calculating dielectric loss in microstrip lines. Numerical results for several different substrates are included. These are compared with other available results and experimental data.

  10. Improved Gain Microstrip Patch Antenna

    DTIC Science & Technology

    2015-08-06

    08-2015 Publication Improved Gain Microstrip Patch Antenna David A. Tonn Naval Under Warfare Center Division, Newport 1176 Howell St., Code 00L...Distribution A An antenna for mounting on a ground plane includes a dielectric substrate for mounting on the ground plane. A conductive patch...GAIN MICROSTRIP PATCH ANTENNA STATEMENT OF GOVERNMENT INTEREST [0001] The invention described herein may be manufactured and used by or for the

  11. Left-handed and right-handed metamaterials composed of split ring resonators and strip wires

    NASA Astrophysics Data System (ADS)

    Woodley, J. F.; Wheeler, M. S.; Mojahedi, M.

    2005-06-01

    The behavior of two structures composed of split ring resonators (SRRs) and strip wires (SWs) is examined through full wave simulations. It is shown that both structures exhibit a transmission peak in the region where the real parts of the electric permittivity and magnetic permeability are presumed to be negative, a property which is usually assumed to imply a negative index of refraction. However, an analysis of the dispersion characteristics and insertion phase of the two structures shows that the first structure, in which the SRRs and SWs are printed on opposite sides of a dielectric substrate, is a left-handed medium in the passband, whereas the second structure, in which SRRs and SWs are printed on the same side, is a right-handed medium in the passband. Hence the transmission magnitude alone does not provide sufficient evidence of a negative index of refraction. To determine the sign of the index correctly, the insertion phase for propagation through several lengths of the structure or calculations of dispersion diagrams are necessary. The impact of the unit cell size on the “handedness” of the structure is also examined.

  12. Chip-integrated optical power limiter based on an all-passive micro-ring resonator.

    PubMed

    Yan, Siqi; Dong, Jianji; Zheng, Aoling; Zhang, Xinliang

    2014-10-20

    Recent progress in silicon nanophotonics has dramatically advanced the possible realization of large-scale on-chip optical interconnects integration. Adopting photons as information carriers can break the performance bottleneck of electronic integrated circuit such as serious thermal losses and poor process rates. However, in integrated photonics circuits, few reported work can impose an upper limit of optical power therefore prevent the optical device from harm caused by high power. In this study, we experimentally demonstrate a feasible integrated scheme based on a single all-passive micro-ring resonator to realize the optical power limitation which has a similar function of current limiting circuit in electronics. Besides, we analyze the performance of optical power limiter at various signal bit rates. The results show that the proposed device can limit the signal power effectively at a bit rate up to 20 Gbit/s without deteriorating the signal. Meanwhile, this ultra-compact silicon device can be completely compatible with the electronic technology (typically complementary metal-oxide semiconductor technology), which may pave the way of very large scale integrated photonic circuits for all-optical information processors and artificial intelligence systems.

  13. Chip-integrated optical power limiter based on an all-passive micro-ring resonator

    PubMed Central

    Yan, Siqi; Dong, Jianji; Zheng, Aoling; Zhang, Xinliang

    2014-01-01

    Recent progress in silicon nanophotonics has dramatically advanced the possible realization of large-scale on-chip optical interconnects integration. Adopting photons as information carriers can break the performance bottleneck of electronic integrated circuit such as serious thermal losses and poor process rates. However, in integrated photonics circuits, few reported work can impose an upper limit of optical power therefore prevent the optical device from harm caused by high power. In this study, we experimentally demonstrate a feasible integrated scheme based on a single all-passive micro-ring resonator to realize the optical power limitation which has a similar function of current limiting circuit in electronics. Besides, we analyze the performance of optical power limiter at various signal bit rates. The results show that the proposed device can limit the signal power effectively at a bit rate up to 20 Gbit/s without deteriorating the signal. Meanwhile, this ultra-compact silicon device can be completely compatible with the electronic technology (typically complementary metal-oxide semiconductor technology), which may pave the way of very large scale integrated photonic circuits for all-optical information processors and artificial intelligence systems. PMID:25327538

  14. Combined pressure and flow sensor integrated in a split-ring resonator microplasma source

    NASA Astrophysics Data System (ADS)

    Snögren, P.; Berglund, M.; Persson, A.

    2016-10-01

    Monitoring and control of the principal properties of a discharge or plasma is vital in many applications, and sensors for measuring them must be integrated close to the plasma source in order to deliver reliable results. This is particularly important, and challenging, in miniaturized systems, where different compatibility issues set the closest level of integration. In this paper, a sensor for simultaneous measurement of the pressure and flow through a stripline split-ring resonator microplasma source is presented. The sensor utilized the fully integrated electrodes positioned upstream and downstream of the microplasma source to study these parameters and was found to deliver uniform and unambiguous results in the pressure and flow range of 1-6 Torr and 1-15 sccm, respectively. Furthermore, hysteresis and drift in the measurements were found to be mitigated by introducing a resistor in parallel with the plasma, in order to facilitate the discharging of the electrodes. Together, the results show that the sensor is fully compatible with the miniaturized microfluidic systems in general and a system for optogalvanic spectroscopy in particular.

  15. Terahertz Response of a Microfabricated Rod Split-Ring-Resonator Electromagnetic Metamaterial

    NASA Astrophysics Data System (ADS)

    Moser, H. O.; Casse, B. D.; Wilhelmi, O.; Saw, B. T.

    2005-02-01

    The first electromagnetic metamaterials (EM3) produced by microfabrication are reported. They are based on the rod split-ring-resonator design as proposed by Pendry et al. [

    IEEE Trans. Microwave Theory Tech. 47, 2075 (1999)IETMAB0018-948010.1109/22.798002
    ] and experimentally confirmed by Smith et al. [
    Phys. Rev. Lett.PRLTAO0031-9007 84, 4184 (2000)10.1103/PhysRevLett.84.4184
    ] in the GHz frequency range. Numerical simulation and experimental results from far infrared (FIR) transmission spectroscopy support the conclusion that the microfabricated composite material is EM3 in the range 1 2.7 THz. This extends the frequency range in which EM3 are available by about 3 orders of magnitude well into the FIR, thereby widely opening up opportunities to verify the unusual physical implications on electromagnetic theory as well as to build novel electromagnetic and optical devices.

  16. Design of photonic crystal based ring resonator for detection of different blood constituents

    NASA Astrophysics Data System (ADS)

    Sharma, Poonam; Sharan, Preeta

    2015-08-01

    In this paper a photonic crystal based ring resonator structure (PCRR) which can sense different bio-constituents in blood in the wavelength range of 1530-1565 nm for biomedical applications has been successfully demonstrated. Simulation and analysis has been done for Biotin-Streptavidin, Bovine Serum Albumin, Cytop (polymer), Ethanol, Glucose solution (40gm/100 ml), Hemoglobin, Blood Plasma, Polyacrylamide and Sylgard184. Finite Difference Time Domain (FDTD) method has been used for the analysis. MEEP (MIT Electromagnetic Equation Propagation) and MPB (MIT Photonic Bands) simulation tools have been used for modeling and designing of PCRR and IPKISS software framework has been used for generation of mask design which can be used for the fabrication of the PCRR sensor. The optical properties of different bio-constituents are studied and the normalized transmitted output power, transmission wavelength and Q factor have been observed for different blood-constituents which can be used for blood analysis.It has been observed that for little change in dielectric constant (ɛ) according to the blood-constituent taken there will be a moderate shift in the transmitted output power, transmission wavelength and quality factor and hence it acts as a sensor. This indicates that it is highly sensitive even for little change in refractive index. Our designed sensor has achieved sensitivity of 343 nm/RIU.

  17. Ultrathin Terahertz Quarter-wave plate based on Split Ring Resonator and Wire Grating hybrid Metasurface

    PubMed Central

    Nouman, Muhammad Tayyab; Hwang, Ji Hyun; Jang, Jae-Hyung

    2016-01-01

    Planar metasurface based quarter-wave plates offer various advantages over conventional waveplates in terms of compactness, flexibility and simple fabrication; however they offer very narrow bandwidth of operation. Here, we demonstrate a planar terahertz (THz) metasurface capable of linear to circular polarization conversion and vice versa in a wide frequency range. The proposed metasurface is based on horizontally connected split ring resonators and is realized on an ultrathin (0.05λ) zeonor substrate. The fabricated quarter waveplate realizes linear to circular polarization conversion in two broad frequency bands comprising 0.64–0.82 THz and 0.96–1.3 THz with an insertion loss ranging from −3.9 to −10 dB. By virtue of ultrathin sub wavelength thickness, the proposed waveplate design is well suited for application in near field THz optical systems. Additionally, the proposed metasurface design offers novel transmission phase characteristics that present further opportunities to realize dynamic polarization control of incident waves. PMID:27958358

  18. A transparent broadband ultrasonic detector based on an optical micro-ring resonator for photoacoustic microscopy

    PubMed Central

    Li, Hao; Dong, Biqin; Zhang, Zhen; Zhang, Hao F.; Sun, Cheng

    2014-01-01

    Photoacoustic microscopy (PAM) does not rely on contrast agent to image the optical absorption contrast in biological tissue. It is uniquely suited for measuring several tissue physiological parameters, such as hemoglobin oxygen saturation, that would otherwise remain challenging. Researchers are designing new clinical diagnostic tools and multimodal microscopic systems around PAM to fully unleash its potential. However, the sizeable and opaque piezoelectric ultrasonic detectors commonly used in PAM impose a serious constraint. Our solution is a coverslip-style optically transparent ultrasound detector based on a polymeric optical micro-ring resonator (MRR) with a total thickness of 250 μm. It enables highly-sensitive ultrasound detection over a wide receiving angle with a bandwidth of 140 MHz, which corresponds to a photoacoustic saturation limit of 287 cm−1, at an estimated noise-equivalent pressure (NEP) of 6.8 Pa. We also established a theoretical framework for designing and optimizing the MRR for PAM. PMID:24675547

  19. Ultrathin Terahertz Quarter-wave plate based on Split Ring Resonator and Wire Grating hybrid Metasurface

    NASA Astrophysics Data System (ADS)

    Nouman, Muhammad Tayyab; Hwang, Ji Hyun; Jang, Jae-Hyung

    2016-12-01

    Planar metasurface based quarter-wave plates offer various advantages over conventional waveplates in terms of compactness, flexibility and simple fabrication; however they offer very narrow bandwidth of operation. Here, we demonstrate a planar terahertz (THz) metasurface capable of linear to circular polarization conversion and vice versa in a wide frequency range. The proposed metasurface is based on horizontally connected split ring resonators and is realized on an ultrathin (0.05λ) zeonor substrate. The fabricated quarter waveplate realizes linear to circular polarization conversion in two broad frequency bands comprising 0.64–0.82 THz and 0.96–1.3 THz with an insertion loss ranging from ‑3.9 to ‑10 dB. By virtue of ultrathin sub wavelength thickness, the proposed waveplate design is well suited for application in near field THz optical systems. Additionally, the proposed metasurface design offers novel transmission phase characteristics that present further opportunities to realize dynamic polarization control of incident waves.

  20. A photonic analog of Möbius strips using coupled optical ring resonators

    NASA Astrophysics Data System (ADS)

    Wu, Li-Ting; Guo, Rui-Peng; Cui, Tie-Jun; Chen, Jing

    2017-02-01

    A Möbius strip has an intriguing topological property in that it only has one non-orientable side. Here we propose to utilize coupled optical ring resonators (ORRs) to simulate the topological effect of Möbius strips. This scheme is based on the fact that the counter-clockwise mode in an ORR only couples to the clockwise mode of an adjacent ORR. We show that if an odd number of ORRs form a closed loop, after a round trip the handedness of the excited mode does not return to the initial one. Only after a double round trip does the mode come back to its initial state. Such a kind of Möbius-type coupling topology can be observed from the strong backward reflection in a common bus that provides the initial excitation. Eigenmodes, reflection and transmission spectra, and field distributions are calculated and analyzed. We also study the situation without Möbius-type coupling. The difference between these two categories is discussed. COMSOL simulations verify our analysis. The importance of this investigation and potential applications are briefly discussed.

  1. Complementary split-ring resonator antenna coupled quantum dot infrared photodetector

    NASA Astrophysics Data System (ADS)

    Cerulo, Giancarlo; Liverini, Valeria; Fedoryshyn, Yuriy; Faist, Jérôme

    2017-02-01

    We present a study of the performance enhancement of a quantum dot infrared photodetector (QDIP), by means of complementary split-ring resonator (CSRR) nano-antennae. The QDIP is based on an asymmetric heterostructure containing a single layer of self-assembled InAs/GaAs quantum dots (QDs). The proximity of the QD plane to the top contact layer is exploited for the coupling with the near-field of the CSRR modes. The co-existence of the CSRR LC mode, at λLC = 7.4 μm, and of non-localized Bragg-like modes, is observed for the two-dimensional array of nano-antennae implemented on the QDIP. At λLC and a temperature T = 10 K, the antenna coupled device is characterized by a responsivity of 44 μA/W and a specific detectivity D* = 1.5 × 108Jones. For the highly localized LC mode, enhancements of a factor 1.7 in responsivity and 2.1 in specific detectivity are observed. Within the sub-wavelength LC mode effective surface, normalizing the overall response to the active surface of the detector, a responsivity enhancement of ˜19 is estimated, showing the potentiality of this approach for the realization of high-performance QDIPs working at normal incidence.

  2. Compact, lower-power-consumption wavelength tunable laser fabricated with silicon photonic-wire waveguide micro-ring resonators.

    PubMed

    Chu, Tao; Fujioka, Nobuhide; Ishizaka, Masashige

    2009-08-03

    A wavelength tunable laser with an SOA and external double micro-ring resonator, which is fabricated with silicon photonic-wire waveguides, is demonstrated. To date, it is the first wavelength tunable laser fabricated with silicon photonic technology. The device is ultra compact, and its external resonator footprint is 700 x 450 microm, which is about 1/25 that of conventional tunable lasers fabricated with SiON waveguides. The silicon resonator shows a wide tuning range covering the C or L bands for DWDM optical communication. We obtained a maximum tuning span of 38 nm at a tuning power consumption of 26 mW, which is about 1/8 that of SiON-type resonators.

  3. Ab initio study of the influence of resonance stabilization on intramolecular ring closure reactions of hydrocarbon radicals.

    PubMed

    Wang, Kun; Villano, Stephanie M; Dean, Anthony M

    2016-03-28

    The intramolecular ring closure reactions of unsaturated hydrocarbon radicals potentially play an important role for the formation of molecular weight growth species, especially during the pyrolysis and oxidation of alkenes under low to intermediate temperatures. In this work we investigated a series of intramolecular cycloaddition reactions of both allylic- and alkyl-type dienyl radicals. In the first set of reactions, a resonant linear radical is converted into a non-resonant cyclic radical. In the second set, a non-resonant linear alkenyl radical isomerizes to either a resonant cyclic radical or a cyclic carbinyl radical. In both cases, three different reaction schemes are examined based on the location of the partially-formed resonance structure in the cyclic transition state. For each reaction scheme, both the endo- and exo-pathways were investigated. High pressure rate parameters are obtained from the results of CBS-QB3 electronic structure calculations combined with canonical transition state theory calculations. The results are discussed in the context of a Benson-type model to examine the impact of the partially-formed resonance stabilization on both the activation energies and pre-exponential factors. The results are compared to previously reported rate parameters for cycloaddition reactions of alkenyl radicals. The differences in the activation energies are primarily due to the bimolecular component of the activation energy. However, in some cases, the presence of the partial resonance structure significantly increases the strain energy for the ring that is formed in the transition state. The pre-exponential factors are also impacted by the formation of a partial resonance structure in the transition state. Lastly, the C6H9 potential energy surface is examined to show how the trends that are outlined here can be used to estimate rate parameters, which are needed to analyze pressure-dependent reaction systems.

  4. Zero-conductance resonances and spin polarizations in three-terminal rings in the presence of spin-orbit coupling

    SciTech Connect

    Zhai, Li-Xue; Wang, Yan; Liu, Jian-Jun

    2014-11-28

    Spin dependent transport in one-dimensional (1D) three-terminal rings is investigated in the presence of the Rashba spin-orbit coupling (RSOC). We focus on zero-conductance resonances and spin polarizations. For these purposes, the transmission functions are derived analytically. The total conductances are analyzed in the complex energy plane with a focus on the zero-pole structure characteristic of transmission (anti)resonances. The spin polarizations in symmetrically and asymmetrically coupled three-terminal rings are studied as a function of the incident electron energy. It is found that in the absence of the RSOC there are three kinds of conductance zeros. In the presence of the RSOC, the zeros of the first and the third kinds are lifted, while some of the second kind persist. The lifting of the conductance zeros is related to the breaking of the spin-reversal symmetry, and the lifted conductance zeros evolve into spin polarization zeros.

  5. Kondo Resonance in a Mesoscopic Ring Coupled to a Quantum Dot: Exact Results for the Aharonov-Bohm-Casher Effects

    SciTech Connect

    Eckle, H.-P.; Johannesson, H.; Stafford, C. A.

    2001-07-02

    We study the persistent currents induced by both the Aharonov-Bohm and Aharonov-Casher effects in a one-dimensional mesoscopic ring coupled to a sidebranch quantum dot at Kondo resonance. For privileged values of the Aharonov-Bohm-Casher fluxes, the problem can be mapped onto an integrable model, exactly solvable by a Bethe ansatz. In the case of a pure magnetic Aharonov-Bohm flux, we find that the presence of the quantum dot has no effect on the persistent current. In contrast, the Kondo resonance interferes with the spin-dependent Aharonov-Casher effect to induce a current which, in the strong-coupling limit, is independent of the number of electrons in the ring.

  6. Kondo resonance in a mesoscopic ring coupled to a quantum dot: exact results for the Aharonov-Bohm-Casher effects.

    PubMed

    Eckle, H P; Johannesson, H; Stafford, C A

    2001-07-02

    We study the persistent currents induced by both the Aharonov-Bohm and Aharonov-Casher effects in a one-dimensional mesoscopic ring coupled to a sidebranch quantum dot at Kondo resonance. For privileged values of the Aharonov-Bohm-Casher fluxes, the problem can be mapped onto an integrable model, exactly solvable by a Bethe ansatz. In the case of a pure magnetic Aharonov-Bohm flux, we find that the presence of the quantum dot has no effect on the persistent current. In contrast, the Kondo resonance interferes with the spin-dependent Aharonov-Casher effect to induce a current which, in the strong-coupling limit, is independent of the number of electrons in the ring.

  7. An optic fiber sensor for multiple gases based on fiber loop ring-down spectroscopy and microring resonator arrays

    NASA Astrophysics Data System (ADS)

    Zhang, Xin; Jian, Jia-wen; Zheng, Yan-gong; Jin, Han; Zou, Jie

    2016-07-01

    A high-sensitivity sensor for multiple gases based on microring array filter and fiber loop ring-down spectroscopy system is proposed and demonstrated. The parameters of the resonators are designed so that the filtered signal from a broadband light source can be tuned with an absorption spectral line of gas. Therefore, through adding microring resonators horizontally and vertically, the number of target gases and filter range are increased. In this research, in the broad spectral range of about 0.9 μm, only the absorption spectral lines of target gases are filtered. The simulation results show that three target gases, CH4, CO2 and HF, can be simultaneously detected by the sensing system. Owing to the fiber loop ring-down spectroscopy, the whole system is optimized in mini-size and sensitivity, and we can choose different sensing methods to enhance the measurement accuracy for high and low concentration conditions.

  8. High-sensitivity optical biosensor based on cascaded Mach-Zehnder interferometer and ring resonator using Vernier effect.

    PubMed

    Jiang, Xianxin; Chen, Yangqing; Yu, Fang; Tang, Longhua; Li, Mingyu; He, Jian-Jun

    2014-11-15

    We demonstrate an ultrahigh sensitivity silicon photonic biosensor based on cascaded Mach-Zehnder interferometer (MZI) and ring resonator with the Vernier effect using wavelength interrogation. Experimental results show that the sensitivities reached 2870 nm/RIU and 21,500 nm/RIU for MZI sensor and MZI-ring sensor, respectively. A biosensing application was demonstrated by monitoring the interaction between goat and antigoat immunoglobulin G (IgG) pairs. The measured results show that 1 ng/ml IgG resulted in 0.035 nm and 0.5 nm wavelength shift for MZI sensor and MZI-ring sensor, respectively. This high performance sensor is promising for medical diagnostic applications.

  9. Strong orbital expansion of Saturn’s inner ice-rich moons through ring torques and mutual resonances during their accretion from a massive ring

    NASA Astrophysics Data System (ADS)

    Salmon, Julien; Canup, Robin M.

    2015-11-01

    Saturn has a diversity of moons with possibly diverse origins. Titan likely formed in Saturn’s sub-nebula (e.g., Canup & Ward 2006). The small moons interior to Mimas are likely recent aggregates of ring’s material spreading through the Roche limit (Charnoz et al. 2010). The origin of the mid-size moons, Mimas through Rhea, is debated. Charnoz et al. (2011) considered a massive ice-rock ring and strong tidal dissipation in Saturn (Q ~ 103), and found that moons out to Rhea could be spawned from such a ring. However such a small value for Q for Saturn is debated. In addition, capture into mutual Mean Motion Resonances (MMR) and resulting eccentricity growth (not included in the Charnoz et al. (2011) model) could lead to orbital destabilization as the moons tidally expand over such large distances (Peale & Canup 2015).Here we consider weak planetary tides (Q ≥ 104) and investigate whether Mimas, Enceladus and Tethys could have been spawned from a massive ice ring (Canup 2010). In this scenario, the rock in these moons would be delivered by material from outside the rings, e.g. by heliocentric impactors during the LHB (Canup 2013). We have expanded a numerical model developed to study the Moon’s accretion (Salmon and Canup 2012, 2014), which couples an analytic Roche-interior disk model to the N-body code SyMBA (Duncan et al. 1998) for satellites, so that we can directly track their accretion and mutual interactions (including MMRs), as well as their tidal interaction with the planet. We consider an initially large Saturn (Fortney et al. 2007) and its progressive contraction, which impacts the strength of tides and the location of the corotation resonance. We perform simulations with and without Dione and Rhea, and study the influence of tidal dissipation into the moons.We find that recoil of the moons due to ring torques, together with capture of moons into MMRs, can produce a distribution similar to that observed. If tidal dissipation in the moons was weak

  10. Input Impedance of the Microstrip SQUID Amplifier

    NASA Astrophysics Data System (ADS)

    Kinion, Darin; Clarke, John

    2008-03-01

    We present measurements of the complex scattering parameters of microstrip SQUID amplifiers (MSA) cooled to 4.2 K. The input of the MSA is a microstrip transmission line in the shape of a square spiral coil surrounding the hole in the SQUID washer that serves as the ground plane. The input impedance is found by measuring the reverse scattering parameter (S11) and is described well by a low-loss transmission line model. We map the low-loss transmission line model into an equivalent parallel RLC circuit in which a resistance R, inductance L, and capacitance C are calculated from the resonant frequency, characteristic impedance and attenuation factor. Using this equivalent RLC circuit, we model the MSA and input network with a lumped circuit model that accurately predicts the observed gain given by the forward scattering parameter (S21). We will summarize results for different coil geometries and terminations as well as SQUID bias conditions. A portion of this work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory in part under Contract W-7405-Eng-48 and in part under Contract DE-AC52-07NA27344 and by Lawrence Berkeley National Laboratory under Contract No. DE-AC02-05CH11231.

  11. High Performance Circularly Polarized Microstrip Antenna

    NASA Technical Reports Server (NTRS)

    Bondyopadhyay, Probir K. (Inventor)

    1997-01-01

    A microstrip antenna for radiating circularly polarized electromagnetic waves comprising a cluster array of at least four microstrip radiator elements, each of which is provided with dual orthogonal coplanar feeds in phase quadrature relation achieved by connection to an asymmetric T-junction power divider impedance notched at resonance. The dual fed circularly polarized reference element is positioned with its axis at a 45 deg angle with respect to the unit cell axis. The other three dual fed elements in the unit cell are positioned and fed with a coplanar feed structure with sequential rotation and phasing to enhance the axial ratio and impedance matching performance over a wide bandwidth. The centers of the radiator elements are disposed at the corners of a square with each side of a length d in the range of 0.7 to 0.9 times the free space wavelength of the antenna radiation and the radiator elements reside in a square unit cell area of sides equal to 2d and thereby permit the array to be used as a phased array antenna for electronic scanning and is realizable in a high temperature superconducting thin film material for high efficiency.

  12. Wavelength division multiplexed and double-port pumped time-bin entangled photon pair generation using Si ring resonator.

    PubMed

    Fujiwara, Mikio; Wakabayashi, Ryota; Sasaki, Masahide; Takeoka, Masahiro

    2017-02-20

    We report a wavelength division multiplexed time-bin entangled photon pair source in telecom wavelength using a 10 μm radius Si ring resonator. This compact resonator has two add ports and two drop ports. By pumping one add port by a continuous laser, we demonstrate an efficient generation of two-wavelength division multiplexed time-bin entangled photon pairs in the telecom C-band, which come out of one drop port, and are then split into the signal and idler photons via a wavelength filter. The resonator structure enhances four-wave mixing for pair generation. Moreover, we demonstrate the double-port pumping where two counter propagating pump lights are injected to generate entanglement from the two drop ports simultaneously. We successfully observe the highly entangled outputs from both two drop ports. Surprisingly, the count rate at each drop port is even increased by twice that of the single-port pumping. Possible mechanisms of this observation are discussed. Our technique allows for the efficient use of the Si ring resonator and widens its functionality for variety of applications.

  13. Magic-T Junction using Microstrip/Slotline Transitions

    NASA Technical Reports Server (NTRS)

    U-yen, Kongpop; Wollack, Edward J.; Doiron, Terence

    2008-01-01

    among all four ports, and to strong parasitic couplings at the microstrip/slotline T junction, where four microstrip lines and a slotline are combined. The present improved broadband magic-T junction (see figure) includes a microstrip ring structure and two microstrip- to-slotline transitions. One of the microstrip/slotline transitions is a small T junction between the ring and a slotline; the other microstrip/slotline transition effects coupling between the slotline and port E. The smallness of the T junction and the use of minimum-size slotline terminations help to minimize radiation loss. An impedance-transformation network that includes multiple quarter-wavelength sections is used to increase the operating bandwidth and minimize the parasitic coupling around the microstrip/slotline T junction. As a result, the improved junction has greater bandwidth and lower phase imbalance at the sum and difference ports than did the prior junction.

  14. Highly adaptive RF excitation scheme based on conformal resonant CRLH metamaterial ring antennas for 7-Tesla traveling-wave magnetic resonance imaging.

    PubMed

    Erni, Daniel; Liebig, Thorsten; Rennings, Andreas; Koster, Norbert H L; Fröhlich, Jürg

    2011-01-01

    We propose an adaptive RF antenna system for the excitation (and manipulation) of the fundamental circular waveguide mode (TE(11)) in the context of high-field (7T) traveling-wave magnetic resonance imaging (MRI). The system consists of composite right-/left-handed (CRLH) meta-material ring antennas that fully conforms to the inner surface of the MRI bore. The specific use of CRLH metamaterials is motivated by its inherent dispersion engineering capabilities, which is needed when designing resonant ring structures for virtually any predefined diameter operating at the given Larmor frequency (i.e. 298 MHz). Each functional group of the RF antenna system consists of a pair of subsequently spaced and correspondingly fed CRLH ring antennas, allowing for the unidirectional excitation of propagating, circularly polarized B(1) mode fields. The same functional group is also capable to simultaneously mold an incoming, counter-propagating mode. Given these functionalities we are proposing now a compound scheme (i.e. periodically arranged multiple antenna pairs)--termed as "MetaBore"--that is apt to provide a tailored RF power distribution as well as full wave reflection compensation virtually at any desired location along the bore.

  15. Ultra sub-wavelength surface plasmon confinement using air-gap, sub-wavelength ring resonator arrays

    PubMed Central

    Lee, Jaehak; Sung, Sangkeun; Choi, Jun-Hyuk; Eom, Seok Chan; Mortensen, N. Asger; Shin, Jung H.

    2016-01-01

    Arrays of sub-wavelength, sub-10 nm air-gap plasmonic ring resonators are fabricated using nanoimprinting. In near infra-red (NIR) range, the resonator supports a single dipole mode which is excited and identified via simple normal illumination and explored through transmission measurements. By controlling both lateral and vertical confinement via a metal edge, the mode volume is successfully reduced down to 1.3 × 10−5 λ03. The advantage of such mode confinement is demonstrated by applying the resonators biosensing. Using bovine serum albumin (BSA) molecules, a dramatic enhancement of surface sensitivity up to 69 nm/nm is achieved as the modal height approaches the thickness of the adsorbed molecule layers. PMID:26923610

  16. Ultra sub-wavelength surface plasmon confinement using air-gap, sub-wavelength ring resonator arrays

    NASA Astrophysics Data System (ADS)

    Lee, Jaehak; Sung, Sangkeun; Choi, Jun-Hyuk; Eom, Seok Chan; Mortensen, N. Asger; Shin, Jung H.

    2016-02-01

    Arrays of sub-wavelength, sub-10 nm air-gap plasmonic ring resonators are fabricated using nanoimprinting. In near infra-red (NIR) range, the resonator supports a single dipole mode which is excited and identified via simple normal illumination and explored through transmission measurements. By controlling both lateral and vertical confinement via a metal edge, the mode volume is successfully reduced down to 1.3 × 10-5 λ03. The advantage of such mode confinement is demonstrated by applying the resonators biosensing. Using bovine serum albumin (BSA) molecules, a dramatic enhancement of surface sensitivity up to 69 nm/nm is achieved as the modal height approaches the thickness of the adsorbed molecule layers.

  17. A volume microstrip RF coil for MRI microscopy.

    PubMed

    Jasiński, Krzysztof; Młynarczyk, Anna; Latta, Peter; Volotovskyy, Vyacheslav; Węglarz, Władyslaw P; Tomanek, Bogusław

    2012-01-01

    Quantitative magnetic resonance imaging (MRI) studies of small samples such as a single cell or cell clusters require application of radiofrequency (RF) coils that provide homogenous B(1) field distribution and high signal-to-noise ratio (SNR). We present a novel design of an MRI RF volume microcoil based on a microstrip structure. The coil consists of two parallel microstrip elements conducting RF currents in the opposite directions, thus creating homogenous RF field within the space between the microstrips. The construction of the microcoil is simple, efficient and cost-effective. Theoretical calculations and finite element method simulations were used to optimize the coil geometry to achieve optimal B(1) and SNR distributions within the sample and predict parameters of the coil. The theoretical calculations were confirmed with MR images of a 1-mm-diameter capillary and a plant obtained with the double microstrip RF microcoil at 11.7 T. The in-plane resolution of MR images was 24 μm × 24 μm.

  18. Stretchable Complementary Split Ring Resonator (CSRR)-Based Radio Frequency (RF) Sensor for Strain Direction and Level Detection

    PubMed Central

    Eom, Seunghyun; Lim, Sungjoon

    2016-01-01

    In this paper, we proposed a stretchable radio frequency (RF) sensor to detect strain direction and level. The stretchable sensor is composed of two complementary split ring resonators (CSRR) with microfluidic channels. In order to achieve stretchability, liquid metal (eutectic gallium-indium, EGaIn) and Ecoflex substrate are used. Microfluidic channels are built by Ecoflex elastomer and microfluidic channel frames. A three-dimensional (3D) printer is used for fabrication of microfluidic channel frames. Two CSRR resonators are designed to resonate 2.03 GHz and 3.68 GHz. When the proposed sensor is stretched from 0 to 8 mm along the +x direction, the resonant frequency is shifted from 3.68 GHz to 3.13 GHz. When the proposed sensor is stretched from 0 to 8 mm along the −x direction, the resonant frequency is shifted from 2.03 GHz to 1.78 GHz. Therefore, we can detect stretched length and direction from independent variation of two resonant frequencies. PMID:27727173

  19. Mode jumping of split-ring resonator metamaterials controlled by high-permittivity BST and incident electric fields

    PubMed Central

    Fu, Xiaojian; Zeng, Xinxi; Cui, Tie Jun; Lan, Chuwen; Guo, Yunsheng; Zhang, Hao Chi; Zhang, Qian

    2016-01-01

    We investigate the resonant modes of split-ring resonator (SRR) metamaterials that contain high-permittivity BST block numerically and experimentally. We observe interesting mode-jumping phenomena from the BST-included SRR absorber structure as the excitation wave is incident perpendicularly to the SRR plane. Specifically, when the electric field is parallel to the SRR gap, the BST block in the gap will induce a mode jumping from the LC resonance to plasmonic resonance (horizontal electric-dipole mode), because the displacement current excited by the Mie resonance in the dielectric block acts as a current channel in the gap. When the electric field is perpendicular to the gap side, the plasmonic resonance mode (vertical electric-dipole mode) in SRR changes to two joint modes contributed simultaneously by the back layer, SRR and BST block, as a result of connected back layer and SRR layer by the displacement current in the BST dielectric block. Based on the mode jumping effect as well as temperature and electric-field dependent dielectric constant, the BST-included SRR metamaterials may have great potentials for the applications in electromagnetic switches and widely tunable metamaterial devices. PMID:27502844

  20. Dual-band microwave absorption properties of metamaterial absorber composed of split ring resonator on carbonyl iron powder composites

    NASA Astrophysics Data System (ADS)

    Lim, Jun-Hee; Ryu, Yo-Han; Kim, Sung-Soo

    2015-05-01

    This study investigated the dual-band absorption properties of metamaterial absorbers composed of a split ring resonator (SRR) on a grounded magnetic substrate. Polymer composites of carbonyl iron powders (CIP) of high permeability and magnetic loss were used as the substrate material. Computational tools were used to model the interaction between electromagnetic waves and materials with the SRR structure. For perpendicular polarization with an electric field (E) perpendicular to the SRR gap, dualband absorption peaks are predicted in the simulation result of reflection loss. Magnetic resonance resulting from antiparallel currents between the SRR and the ground plane is observed at the frequencies of two absorption peaks. The first strong absorption peak at the lower frequency (3.3 GHz) is due to magnetic resonance at the wire part of the SRR. The second absorption peak at the higher frequency (7.2 GHz) is due to magnetic resonance at the SRR split gap. The decreased capacitance with increased gap spacing moves the second absorption frequency to higher frequencies, while the first absorption peak is invariant with gap spacing. In the case of dual gaps at the opposite sides of the SRR, a single absorption peak is predicted due to the elimination of low-frequency resonance. For parallel polarization with the E-field parallel to the SRR gap, a single absorption peak is predicted, corresponding to magnetic resonance at the SRR wire.[Figure not available: see fulltext.

  1. Mode jumping of split-ring resonator metamaterials controlled by high-permittivity BST and incident electric fields

    NASA Astrophysics Data System (ADS)

    Fu, Xiaojian; Zeng, Xinxi; Cui, Tie Jun; Lan, Chuwen; Guo, Yunsheng; Zhang, Hao Chi; Zhang, Qian

    2016-08-01

    We investigate the resonant modes of split-ring resonator (SRR) metamaterials that contain high-permittivity BST block numerically and experimentally. We observe interesting mode-jumping phenomena from the BST-included SRR absorber structure as the excitation wave is incident perpendicularly to the SRR plane. Specifically, when the electric field is parallel to the SRR gap, the BST block in the gap will induce a mode jumping from the LC resonance to plasmonic resonance (horizontal electric-dipole mode), because the displacement current excited by the Mie resonance in the dielectric block acts as a current channel in the gap. When the electric field is perpendicular to the gap side, the plasmonic resonance mode (vertical electric-dipole mode) in SRR changes to two joint modes contributed simultaneously by the back layer, SRR and BST block, as a result of connected back layer and SRR layer by the displacement current in the BST dielectric block. Based on the mode jumping effect as well as temperature and electric-field dependent dielectric constant, the BST-included SRR metamaterials may have great potentials for the applications in electromagnetic switches and widely tunable metamaterial devices.

  2. Excitation of ultrasharp trapped-mode resonances in mirror-symmetric metamaterials

    NASA Astrophysics Data System (ADS)

    Yang, Shengyan; Liu, Zhe; Xia, Xiaoxiang; E, Yiwen; Tang, Chengchun; Wang, Yujin; Li, Junjie; Wang, Li; Gu, Changzhi

    2016-06-01

    We experimentally demonstrate a metamaterial structure composed of two mirror-symmetric joint split ring resonators (JSRRs) that support extremely sharp trapped-mode resonance with a large modulation depth in the terahertz region. Contrary to the regular mirror-arranged SRR arrays in which both the subradiant inductive-capacitive (LC) resonance and quadrupole-mode resonance can be excited, our designed structure features a metallic microstrip bridging the adjacent SRRs, which leads to the emergence of an otherwise inaccessible ultrahigh-quality-factor resonance. The ultrasharp resonance occurs near the Wood-Rayleigh anomaly frequency, and the underlying mechanism can be attributed to the strong coupling between the in-plane propagating collective lattice surface mode originating from the array periodicity and localized surface plasmon resonance in mirror-symmetric coupled JSRRs, which dramatically reduces radiative damping. The ultrasharp resonance shows great potential for multifunctional applications such as plasmonic switching, low-power nonlinear processing, and chemical and biological sensing.

  3. A wideband textile antenna with a ring-slotted AMC plane

    NASA Astrophysics Data System (ADS)

    Hussin, Ezzaty Faridah Nor Mohd; Soh, Ping Jack; Jamlos, Mohd Faizal; Lago, Herwansyah; Al-Hadi, Azremi Abdullah; Rahiman, Mohd Hafiz Fazalul

    2017-01-01

    A wideband microstrip-based textile planar antenna with artificial magnetic conductor (AMC) plane is presented. The antenna is initially designed using the combination of two rectangular microstrip antennas operating at 1.5 and 2.5 GHz before being further optimized for wideband operation using various broadbanding techniques. This optimized radiator is then placed over an array of unit elements forming an AMC plane. Each unit element is formed using a square patch slotted using a circular ring and is designed to resonate at 2 GHz. To validate the contribution of the AMC plane in reducing backward radiation toward the human user, the performance of the proposed antenna is compared to a similar antenna without the AMC plane. This investigation indicated that the proposed antenna is capable of reducing backlobe while simultaneously increasing gain to 3.38 dB and improving bandwidth up to 52%.

  4. The microstrip wideband filter

    NASA Astrophysics Data System (ADS)

    Khodenkov, S. A.; Belyaev, B. A.; Balva, Ya F.; Aplesnin, S. S.; Bandurina, O. N.

    2016-11-01

    The filter of high frequency-selective properties is developed. The central six-mode resonator of the design which can be used in the aerospace equipment is electromagnetically connected with six single-mode resonators. The good agreement of the calculated data in comparison with the data received on the experimental model of a design is shown.

  5. Narrow line-width single-longitudinal-mode fiber laser using silicon-on-insulator based micro-ring-resonator

    NASA Astrophysics Data System (ADS)

    Liu, Yang; Hsu, Yung; Hsu, Chin-Wei; Yang, Ling-Gang; Chow, Chi-Wai; Yeh, Chien-Hung; Lai, Yin-Chieh; Tsang, Hon-Ki

    2016-02-01

    In this work, we propose and demonstrate a stable single-longitudinal-mode (SLM) fiber laser with narrow line-width by using an integrated silicon-on-insulator micro-ring resonator (SOI MRR) and two subsidiary fiber rings for the first time, to the best of our knowledge. The laser is tunable over the wavelength range from 1546 to 1570 nm, with only step tuning of 2 nm steps. A maximum 49 dB side mode suppression ratio (SMSR) can be achieved. The compact SOI MRR provides a large free-spectral-range (FSR), while the subsidiary rings provide Vernier effect producing a single lasing mode. The FSR of the SOI MRR can be very large and controllable (since it is easy to fabricate small SOI MRR when compared with making small fiber-rings) using the complementary-metal-oxide-semiconductor (CMOS) compactable SOI fabrication processes. In our proposed laser, the measured single sideband (SSB) spectrum shows that the densely spaced longitudinal modes can be significantly suppressed to achieve SLM. The laser linewidth is only 3.5 kHz measured by using the self-heterodyne method. 30 min stability evaluation in terms of lasing wavelength and optical power is performed; showing the optical wavelength and power are both very stable, with fluctuations of only 0.02 nm and 0.8 dB, respectively.

  6. SiGe BiCMOS balanced transmission line based on coplanar waveguide and split ring resonator

    NASA Astrophysics Data System (ADS)

    Serrano, Enrique; Borja, Alejandro L.; Boccia, Luigi; Cascon, Joaquin; Ibrahim, Safwat; Calzona, D.; Amendola, G.

    2016-06-01

    In this work, the design of a right-/left-handed composite transmission line implementation with passband characteristics is demonstrated on 0.13 µm silicon-germanium bipolar CMOS (SiGe BiCMOS) technology. The proposed structure is formed by a shorted coplanar waveguide transmission line loaded with split ring resonators (SRRs). As it will be shown, by controlling the geometry of the SRRs as well as their electric coupling with the host line, it is possible to achieve a balanced passband response with widespread bandwidth at millimeter wave frequencies. Besides, this paper introduces a configuration that allows to significantly lower the resonant frequency of the SRRs by loading the rings with Metal-Insulator-Metal capacitors. It will be illustrated how this approach allows to reduce the center band frequency of about 40% preserving the balanced behavior and without increasing the resonator size. Finally, the proposed design was experimentally validated with a prototype exhibiting an extended passband with a fractional bandwidth of 19.3% and -3.2 dB of insertion loss around the central frequency of 60 GHz. The use of these transmission lines can be foreseeing in high-capacity millimeter wave communication systems which require compact passband blocks integrated on chip.

  7. Graphene plasmonics for tuning photon decay rate near metallic split-ring resonator in a multilayered substrate.

    PubMed

    Chen, Yongpin P; Sha, Wei E I; Jiang, Lijun; Hu, Jun

    2015-02-09

    Study of photon decay rate is essential to various optical devices, where graphene is an emerging building block due to its electrical tunability. In this paper, we study photon decay rate of a quantum emitter near a metallic split-ring resonator, which is embedded in a multilayered substrate incorporating a graphene layer. Analyzing photon decay rate in such a complex multilayered system is not only computationally challenging but also highly important to experimentally realizable devices. First, the dispersion relation of graphene plasmonics supported at a dieletric/graphene/dielectric structure is investigated systematically. Meanwhile, the dispersion relation of metallic plasmonics supported at a dielectric/metal structure is studied comparatively. According to our investigation, graphene offers several flexible tuning routes for manipulating photon decay rate, including tunable chemical potential and the emitter's position and polarization. Next, considering plasmonic waves in a graphene sheet occur in the infrared regime, we carefully design a metallic split ring resonating around the same frequency range. Consequently, this design enables a mutual interaction between graphene plasmonics and metallic plasmonics. The boundary element method with a multilayered medium Green's function is adopted in the numerical simulation. Blue-shifted and splitting resonance peaks are theoretically observed, which suggests a strong mode coupling. Moreover, the mode coupling has a switch on-off feature via electrostatically doping the graphene sheet. This work is helpful to dynamically manipulate photon decay rate in complex optical devices.

  8. Real-time cancellation of temperature induced resonance shifts in SOI wire waveguide ring resonator label-free biosensor arrays.

    PubMed

    Xu, D-X; Vachon, M; Densmore, A; Ma, R; Janz, S; Delâge, A; Lapointe, J; Cheben, P; Schmid, J H; Post, E; Messaoudène, Sonia; Fédéli, Jean-Marc

    2010-10-25

    A comprehensive investigation of real-time temperature-induced resonance shift cancellation for silicon wire based biosensor arrays is reported for the first time. A reference resonator, protected by either a SU8 or SiO(2) cladding layer, is used to track temperature changes. The temperature dependence of resonators in aqueous solutions, pertinent to biosensing applications, is measured under steady-state conditions and the operating parameters influencing these properties are discussed. Real-time measurements show that the reference resonator resonances reflect the temperature changes without noticeable time delay, enabling effective cancellation of temperature-induced shifts. Binding between complementary IgG protein pairs is monitored over 4 orders of magnitude dynamic range down to a concentration of 20 pM, demonstrating a resolvable mass of 40 attograms. Reactions are measured over time periods as long as 3 hours with high stability, showing a scatter corresponding to a fluid refractive index fluctuation of ± 4 × 10(-6) in the baseline data. Sensor arrays with a SU8 protective cladding are easy to fabricate, while oxide cladding is found to provide superior stability for measurements involving long time scales.

  9. Engineered SOI slot waveguide ring resonator V-shape resonance combs for refraction index sensing up to 1300nm/RIU (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Zhang, Weiwei; Serna, Samuel; Le Roux, Xavier; Vivien, Laurent; Cassan, Eric

    2016-05-01

    Bio-detection based on CMOS technology boosts the miniaturization of detection systems and the success on highly efficient, robust, accurate, and low coast Lab-on-Chip detection schemes. Such on chip detection technologies have covered healthy related harmful gases, bio-chemical analytes, genetic micro RNA, etc. Their monitoring accuracy is mainly qualified in terms of sensitivity and limit of the detection (LOD) of the detection system. In this context, recently developed silicon on insulator (SOI) optical devices have displayed highly performant detection abilities that LOD could go beyond 10-8RIU and sensitivity could exceeds 103nm/RIU. The SOI integrated optical sensing devices include strip/slotted waveguide consisting in structures like Mach-Zehnder interferometers (MZI), ring resonators (RR), nano cavities, etc. Typically, hollow core RR and nano-cavities could exhibit higher sensitivity due to their optical mode confinement properties with a partial localization of the electric field in low index sensing regions than devices based on evanescent field tails outside of the optical cores. Furthermore, they also provide larger sensing areas for surface functionalization to reach higher sensitivities and lower LODs. The state of art of hollow core devices, either based on Bragg gratings formed from a slot waveguide cavity or photonic crystal slot cavities, show sensitivities (S) up to 400nm/RIU and Figure of Merit (FOM) around 3,000 in water environment, FOM being defined as the inverse of LOD and precisely as FOM=SQ/λ, with λ the resonance wavelength and Q the quality factor of the considered resonator. Such high achieved FOMs in nano cavities are mainly due to their large Q factors around 15,000. While for mostly used RR, which do not require particular design strategies, relatively low Q factors around 1800 in water are met and moderate sensitivities about 300nm/RIU are found. In this work, we present here a novel slot ring resonator design to make

  10. Sub-kHz lasing of a CaF₂ whispering gallery mode resonator stabilized fiber ring laser.

    PubMed

    Collodo, M C; Sedlmeir, F; Sprenger, B; Svitlov, S; Wang, L J; Schwefel, H G L

    2014-08-11

    We utilize a high quality calcium fluoride whispering-gallery-mode resonator to passively stabilize a simple erbium doped fiber ring laser with an emission frequency of 196THz (wavelength 1530nm) to an instantaneous linewidth below 650Hz. This corresponds to a relative stability of 3.3 × 10(-12) over 16μs. In order to characterize the linewidth we use two identical self-built lasers and a commercial laser to determine the individual lasing linewidth via the three-cornered-hat method. We further show that the lasers are finely tunable throughout the erbium gain region.

  11. Passive mode-locking of fiber ring laser at the 337th harmonic using gigahertz acoustic core resonances.

    PubMed

    Kang, M S; Joly, N Y; Russell, P St J

    2013-02-15

    We report the experimental demonstration of a passively mode-locked Er-doped fiber ring laser operating at the 337th harmonic (1.80 GHz) of the cavity. The laser makes use of highly efficient Raman-like optoacoustic interactions between the guided light and gigahertz acoustic resonances trapped in the micron-sized solid glass core of a photonic crystal fiber. At sufficient pump power levels the laser output locks to a repetition rate corresponding to the acoustic frequency. A stable optical pulse train with a side-mode suppression ratio higher than 45 dB was obtained at low pump powers (~60 mW).

  12. Pulse dynamics of dissipative soliton resonance with large duration-tuning range in a fiber ring laser.

    PubMed

    Luo, Zhi-Chao; Cao, Wen-Jun; Lin, Zhen-Bin; Cai, Ze-Rong; Luo, Ai-Ping; Xu, Wen-Cheng

    2012-11-15

    The pulse dynamics operating in dissipative soliton resonance (DSR) region is experimentally investigated in a fiber ring laser. With the increase of pump power, the pulse profile transit from sech-like to rectangular shape was observed. The generated pulse in DSR region exhibits the conventional soliton spectrum with sideband generation. The duration-tuning range of the rectangular pulse is up to the cavity roundtrip time. Particularly, during the process of pulse duration broadening it was found that the rectangular pulse would trap a weak pulse generated from cw background. The obtained results may be useful for better understanding the DSR phenomenon.

  13. Polarization-insensitive wide-angle multiband metamaterial absorber with a double-layer modified electric ring resonator array

    NASA Astrophysics Data System (ADS)

    Li, Wangchang; Zhou, Xiang; Ying, Yao; Qiao, Xiaojing; Qin, Faxiang; Li, Qian; Che, Shenglei

    2015-06-01

    In this letter, we report the design, demonstration and discussion of a multi- and broad- band metamaterial absorber (MMA) with wide angle polarization insensitive at microwave region. The MMA consisting of double layered electric ring resonator (ERR) with four fold rotational symmetry structure is used to realize a desirable absorption. Strong triple absorption peaks in 2˜8 GHz and broadband microwave absorption in 10˜18 GHz are demonstrated. The absorption can be reached as high as 0.73, 0.73 and 0.94 at 4.41, 5.15, 6.37 GHz, respectively. The multiband absorbing features originate from the synergetic effects of dipole resonance and Fabry-Pérot interference between two or three metasurfaces. This design is of high practical for constructing broad band and multiband absorber for electromagnetic intereference/compatibility (EMI/EMC) applications.

  14. A high-sensitivity 135 GHz millimeter-wave imager by compact split-ring-resonator in 65-nm CMOS

    NASA Astrophysics Data System (ADS)

    Li, Nan; Yu, Hao; Yang, Chang; Shang, Yang; Li, Xiuping; Liu, Xiong

    2015-11-01

    A high-sensitivity 135 GHz millimeter-wave imager is demonstrated in 65 nm CMOS by on-chip metamaterial resonator: a differential transmission-line (T-line) loaded with split-ring-resonator (DTL-SRR). Due to sharp stop-band introduced by the metamaterial load, high-Q oscillatory amplification can be achieved with high sensitivity when utilizing DTL-SRR as quench-controlled oscillator to provide regenerative detection. The developed 135 GHz mm-wave imager pixel has a compact core chip area of 0.0085 mm2 with measured power consumption of 6.2 mW, sensitivity of -76.8 dBm, noise figure of 9.7 dB, and noise equivalent power of 0.9 fW/√{HZ } Hz. Millimeter-wave images has been demonstrated with millimeter-wave imager integrated with antenna array.

  15. Analytical and experimental procedures for determining propagation characteristics of millimeter-wave gallium arsenide microstrip lines

    NASA Technical Reports Server (NTRS)

    Romanofsky, Robert R.

    1989-01-01

    In this report, a thorough analytical procedure is developed for evaluating the frequency-dependent loss characteristics and effective permittivity of microstrip lines. The technique is based on the measured reflection coefficient of microstrip resonator pairs. Experimental data, including quality factor Q, effective relative permittivity, and fringing for 50-omega lines on gallium arsenide (GaAs) from 26.5 to 40.0 GHz are presented. The effects of an imperfect open circuit, coupling losses, and loading of the resonant frequency are considered. A cosine-tapered ridge-guide text fixture is described. It was found to be well suited to the device characterization.

  16. Broadband microstrip antenna with a hairpin bandpass filter

    NASA Astrophysics Data System (ADS)

    Belyaev, B. A.; Voloshin, A. S.; Morozov, N. V.; Galeev, R. G.

    2015-03-01

    A new design for a broadband microstrip antenna is proposed, the working band of which is broadened using a bandpass filter based on two hairpin resonators electromagnetically coupled with a half-wave radiating resonator with a rectangular strip conductor. It is shown that the operating frequency range of this antenna is significantly extended as compared with that of analogous antennas, while its directivity and polarization diagrams remain highly stable within this range, which makes this design promising for applications. Operability of the antenna is demonstrated using its operating prototype. The measured characteristics of the antenna prototype agree well with the calculated data.

  17. Triangular Ring Resonator: Direct Measurement of the Parity-Odd Parameters of the Photon Sector of SME

    NASA Astrophysics Data System (ADS)

    Exirifard, Qasem

    2014-03-01

    We introduce the Triangular Ring (TR) resonator. We show that the difference between the clockwise and anti-clockwise resonant frequencies of a vacuum TR resonator is sensitive to the birefringence parity-odd parameters of the photon's sector of the minimal Standard Model Extension (mSME): the Standard Model plus all the perturbative parameters encoding the break of the Lorentz symmetry. We report that utilizing the current technology allows for direct measurement of these parameters with a sensitivity of the parity-even ones and improves the best current resonator bounds by couple of orders of magnitudes. We note that, designing an optical table that rotates perpendicular to the gravitational equipotential surface (geoid) allows for direct measurement of the constancy of the light speed at the vicinity of the earth in all directions, in particular, perpendicular to the geoid. If this table could achieve the precision of the ordinary tables, then it would improve the GPS bounds on the constancy of the light speed perpendicular to geoid by about eight orders of magnitude.

  18. The Millimeter-Wave Properties of Superconducting Microstrip Lines

    NASA Technical Reports Server (NTRS)

    Vayonakis, A.; Luo, C.; Leduc, H. G.; Schoelkopf, R.; Zmuidzinas, J.

    2002-01-01

    We have developed a novel technique for making high quality measurements of the millimeter-wave properties of superconducting thin-film microstrip transmission lines. Our experimental technique currently covers the 75-100 GHz band. The method is based on standing wave resonances in an open ended transmission line. We obtain information on the phase velocity and loss of the microstrip. Our data for Nb/SiO/Nb lines, taken at 4.2 K and 1.6 K, can be explained by a single set of physical parameters. Our preliminary conclusion is that the loss is dominated by the SiO dielectric, with a temperature-independent loss tangent of 5.3 +/- 0.5 x 10(exp -3) for our samples.

  19. Homometallic and Heterometallic Antiferromagnetic Rings: Magnetic Properties Studied by Nuclear Magnetic Resonance

    SciTech Connect

    Casadei, Cecilia

    2011-01-01

    The aim of the present thesis is to investigate the local magnetic properties of homometallic Cr8 antiferromagnetic (AFM) ring and the changes occurring by replacing one Cr3+ ion with diamagnetic Cd2+ (Cr7Cd) and with Ni2+ (Cr7Ni). In the heterometallic ring a redistribution of the local magnetic moment is expected in the low temperature ground state. We have investigated those changes by both 53Cr-NMR and 19F-NMR. We have determined the order of magnitude of the transferred hyperfine coupling constant 19F - M+ where M+ = Cr3+, Ni2+ in the different rings. This latter result gives useful information about the overlapping of the electronic wavefunctions involved in the coordinative bond.

  20. Effect of U-Slot Length Variations on the Performance of Stacked Microstrip Antenna

    NASA Astrophysics Data System (ADS)

    Yadahalli, Ravi M.; Usha, K. K.; Ayachit, N. H.; Vani, R. M.; Fatima, Sara F.; Hunagund, P. V.

    2007-07-01

    Antenna miniaturization plays an important role in the design of modern personal wireless systems. Several minimization techniques have been known for a long time. The mail minimization tools are loading the antenna with lumped elements, high permittivity dielectric materials or conducting additions; using a ground plane with short circuits and optimizing the geometry. In this paper, a compact stacked microstrip antenna with loaded U-slot on the driven (lower) patch and probe feed structure is proposed. The purpose of this paper is to study the variations of a U-slot length with the parameters of stacked microstrip antenna such as input impedance, bandwidth and resonant frequency etc. The paper emphasizes the significant change observed in the performance of compact stacked microstrip antenna. Earlier work has utilized a U-slot on the planar microstrip antenna and the effect of slot width on performance of microstrip antenna is studied. The software package IE3D® version 11.5 was used to simulate the antenna structures. The simulation results show that, the size reduction is achieved by inserting U-slot in the radiating element. Further, it is observed from the simulation that maximum overall impedance bandwidth is achieved for width of U-slot LS = 22 mm, which is 277.78 MHz. This developed microstrip antenna is small enough to be easily accommodated in wireless applications.

  1. Microwave Power Transmission Using Electromagnetic Coupling of Open-Ring Resonators

    DTIC Science & Technology

    2012-11-01

    micro - strip line with the same distance between the connectors. Fig.4.4. Transmission through de-ionized water. “0” indicates the case of no sheets...for 2.45GHz signal transmission. The ring diameter is 9.9mm. The signal is fed through a 50Ω micro - strip line. The rings are connected to an SMA...connector through the micro - strip line with 18 μm thick copper. The back side of the board is covered with copper which is used as a ground plane. To

  2. A laser system for the TESLA photon collider based on an external ring resonator

    NASA Astrophysics Data System (ADS)

    Will, I.; Quast, T.; Redlin, H.; Sandner, W.

    2001-10-01

    We present a concept of a laser system for a photon collider at the TESLA linac. It is based on an external optical ring cavity which is pumped by a short-pulse laser. A detailed discussion of the geometry of the external cavity is given.

  3. Applications of optical micro-ring and micro-disk resonators as physical, chemical, and biological sensors

    NASA Astrophysics Data System (ADS)

    Bhola, Bipin

    This dissertation presents the applications of optical micro-ring and micro-disk resonators as various sensors in physical, chemical, and biological applications. This work describes the functioning of 5 different sensors and suggests ways for optimizing the performance of each of them. All of these sensors work on the principle of shift in the resonance wavelength of the micro-ring or the micro-disk in response to an external physical, chemical or biological perturbation. The first portion describes the functioning of a ring resonator device and details the various parameters which are important in sensing applications. Then a strain sensor, an accelerometer, and a humidity sensor based on polymer micro-ring resonator are described. The strain sensor has a sensitivity of 0.32pm/muε and a dynamic range of 17000muε, the accelerometer has a sensitivity of 31pm/g and a dynamic range of +/-7g, whereas, the humidity sensor has a sensitivity of 16pm/%RH and a dynamic range of 72%. The dependency of each of their sensitivities and dynamic ranges on various geometrical parameters are also discussed. The response time of the humidity sensor was reduced to less than 200ms which enables us to utilize this device as a human breathing monitor in hospitals. The second portion of the thesis, discusses the possible incorporation of ultra-high-Q silica micro-disk resonators, developed at the Jet Propulsion Laboratory by Mr. Thanh M. Le, into various sensing devices. This device is first proposed as a biosensor for detecting trace amounts of specific biomolecules. The first experiments are performed for developing the silica micro-disk as a biosensor. In this experiment, the sensitivity of the micro-disk as a function of change in refractive index of the surrounding medium is demonstrated. The observed sensitivity is 11.82nm/RIU (Refractive Index Units). Then, the possibility of using this device as a specific biosensor is explored. The method for surface functionalization of the

  4. The local surface plasmon resonance property and refractive index sensitivity of metal elliptical nano-ring arrays

    SciTech Connect

    Lin, Weihua Wang, Qian; Dong, Anhua; Li, Qiuze

    2014-11-15

    In this paper, we systematically investigate the optical property and refractive index sensitivity (RIS) of metal elliptical nano-ring (MENR) arranged in rectangle lattice by finite-difference time-domain method. Eight kinds of considered MENRs are divided into three classes, namely fixed at the same outer size, at the same inner size, and at the same middle size. All MENR arrays show a bonding mode local surface plasmon resonance (LSPR) peak in the near-infrared region under longitudinal and transverse polarizations, and lattice diffraction enhanced LSPR peaks emerge, when the LSPR peak wavelength (LSPRPW) matches the effective lattice constant of the array. The LSPRPW is determined by the charge moving path length, the parallel and cross interactions induced by the stable distributed charges, and the moving charges inter-attraction. High RIS can be achieved by small particle distance arrays composed of MENRs with big inner size and small ring-width. On the other hand, for a MENR array, the comprehensive RIS (including RIS and figure of merit) under transverse polarization is superior to that under longitudinal polarization. Furthermore, on condition that compared arrays are fixed at the same lattice constant, the phenomenon that the RIS of big ring-width MENR arrays may be higher than that of small ring-width MENR arrays only appears in the case of compared arrays with relatively small lattice constant and composed of MENRs fixed at the same inner size simultaneously. Meanwhile, the LSPRPW of the former MENR arrays is also larger than that of the latter MENR arrays. Our systematic results may help experimentalists work with this type of systems.

  5. Wideband Microstrip Antenna-Feeding Array

    NASA Technical Reports Server (NTRS)

    Huang, John

    1990-01-01

    Special impedance-matching probes help reduce feed complexity. Lightweight array of microstrip antenna elements designed to transmit and illuminate reflector antenna with circularly polarized radiation at 1,545 to 1,550 MHz and to receive circularly polarized radiation at 1,646 to 1,660 MHz. Microstrip array is cluster of 7 subarrays containing total of 28 microstrip patches. Produces cicularly polarized beam with suitable edge taper to illuminate reflector antenna. Teardrop-shaped feed probe provides gradual change of field from coaxial transmission line into microstrip substrate. Intended to be part of larger overlapping-cluster array generating multiple contiguous beams.

  6. Planar microstrip YAGI antenna array

    NASA Astrophysics Data System (ADS)

    Huang, John

    1993-06-01

    A directional microstrip antenna includes a driven patch surrounded by an isolated reflector and one or more coplanar directors, all separated from a ground plane on the order of 0.1 wavelength or less to provide end fire beam directivity without requiring power dividers or phase shifters. The antenna may be driven at a feed point a distance from the center of the driven patch in accordance with conventional microstrip antenna design practices for H-plane coupled or horizontally polarized signals. The feed point for E-plane coupled or vertically polarized signals is at a greater distance from the center than the first distance. This feed point is also used for one of the feed signals for circularly polarized signals. The phase shift between signals applied to feed points for circularly polarized signals must be greater than the conventionally required 90 degrees and depends upon the antenna configuration.

  7. Planar microstrip YAGI antenna array

    NASA Technical Reports Server (NTRS)

    Huang, John (Inventor)

    1993-01-01

    A directional microstrip antenna includes a driven patch surrounded by an isolated reflector and one or more coplanar directors, all separated from a ground plane on the order of 0.1 wavelength or less to provide end fire beam directivity without requiring power dividers or phase shifters. The antenna may be driven at a feed point a distance from the center of the driven patch in accordance with conventional microstrip antenna design practices for H-plane coupled or horizontally polarized signals. The feed point for E-plane coupled or vertically polarized signals is at a greater distance from the center than the first distance. This feed point is also used for one of the feed signals for circularly polarized signals. The phase shift between signals applied to feed points for circularly polarized signals must be greater than the conventionally required 90 degrees and depends upon the antenna configuration.

  8. Conformal microstrip arrays on cylinders

    NASA Astrophysics Data System (ADS)

    Ashkenazy, J.; Shtrikman, S.; Treves, D.

    1988-04-01

    Design and measured results for two X-band conformal microstrip arrays are presented. The two 4 x 4 arrays are built on the surface of a cylinder of small radius. They differ by the orientation of small radius. They differ by the orientation of the elements relative to the cylinder axis. The measured directivities and radiation patterns are in reasonable agreement with theoretical predictions.

  9. Optical band-stop filter and multi-wavelength channel selector with plasmonic complementary aperture embedded in double-ring resonator

    NASA Astrophysics Data System (ADS)

    Wei, Zhongchao; Zhang, Xiaomeng; Zhong, Nianfa; Tan, Xiaopei; Li, Xianping; Liu, Yuebo; Wang, Faqiang; Meng, Hongyun; Liang, Ruisheng

    2017-02-01

    A compact nanoscale wavelength band-stop filter with aperture embedded in double-ring resonator is proposed and numerically investigated by using Finite-Difference Time-Domain (FDTD) method. With a narrow aperture created between embedded double rings, the modes of the split-ring cavity can be modulated by the aperture in different manners when the parameters of the aperture are changed. Furthermore, the absorption peaks of resonator modes can be selectively inhibited by altering the positions of the aperture without changing outer size of the resonator. Based on above characteristics, a 1 × 2 multiple-contact channel selector is designed with a rotating aperture which can select the output waveguide. The proposed filter and selector have potential applications in highly integrated optical circuits.

  10. Demonstration of a wavelength monitor comprised of racetrack-ring resonators with defect mediated photodiodes operating in the C-band.

    PubMed

    Dey, Rajat; Doylend, Jonathan; Ackert, Jason; Evans, Andrew; Jessop, Paul; Knights, Andrew

    2013-10-07

    A CMOS compatible wavelength monitor comprised of two thermally tuned racetrack-ring resonators with defect mediated photodiode structures is experimentally demonstrated in monolithic silicon. Each resonator is independently tuned so as to determine an unknown input wavelength by tuning the resonance peak locations until there is overlap between the two comb spectra. The presence of two of these resonator/heater components, each with a different free spectral range, increases the unambiguous measurement range when compared to one component used on its own.

  11. Thermoelastic damping effect of the micro-ring resonator with irregular mass and stiffness

    NASA Astrophysics Data System (ADS)

    Kim, Jung-Hwan; Kim, Ji-Hwan

    2016-05-01

    Fundamentally, vibration characteristic is a main factor for the stability of structures. In this regard, the irregularity of mass and stiffness distributions for the structure have been an interesting issue for many years. Recently, the Micro Electro Mechanical Systems (MEMS) are developed for various applications such as gyro sensors. In the present work, in-plane vibration of micro-ring structure with multiple finite-sized imperfections is investigated. Then, the unbalance of the structure is represented using Heaviside Step Function for the inextensional modeling of the ring. Also, thermoelastic damping (TED) due to internal friction is studied based on Fourier's one-dimensional heat conduction equation using Laplace Transform. To obtain the quality-factors (Q-factors) for imperfect micro-ring, analytical solutions are calculated from governing equations of motion with TED. And then, the natural frequencies and the Q-factors are observed to separate into lower and higher modes. Additionally, the vibration mode shapes are presented, and the frequency trimming concept due to attached imperfections is investigated.

  12. Optical-vortex pair creation and annihilation and helical astigmatism of a nonplanar ring resonator

    SciTech Connect

    Heckenberg, N.R.; Vaupel, M.; Malos, J.T.; Weiss, C.O.

    1996-09-01

    The creation and annihilation of pairs of optical vortices have been studied in transitions between patterns produced in a photorefractive oscillator. Smooth metamorphosis between stable patterns occurs through pair creation or annihilation but can be modeled using superposition of modes taking into account lifting of degeneracy of helical modes by helical astigmatism of the resonator. {copyright} {ital 1996 The American Physical Society.}

  13. Surface-emitting circular DFB, disk-, and ring-Bragg resonator lasers with chirped gratings. II: nonuniform pumping and far-field patterns.

    PubMed

    Sun, Xiankai; Yariv, Amnon

    2009-01-05

    This is a continuation of our previous work [Opt. Express 16, 9155 (2008)]. In this paper we investigate the effect of nonuniform pumping on the modal properties of surface-emitting chirped circular grating lasers. By numerically solving the coupled-mode equations and matching the boundaries we compare and discuss the threshold pump levels and frequency detuning factors for three pumping profiles: uniform, Gaussian, and annular. Depending on the overlap of the pumping and modal profiles, Gaussian pumping results in the lowest threshold pump levels except for the fundamental mode of ring Bragg resonator laser, and annular pumping provides larger threshold discrimination between the fundamental and first-order modes of circular DFB and ring Bragg resonator lasers, which is favorable for single-mode operation in these lasers. We also study the far-field patterns of the fundamental modes of circular DFB, disk-, and ring- Bragg resonator lasers. Circular DFB and ring Bragg resonator lasers have the first-order dominating peak, while disk Bragg resonator laser exhibits the zeroth-order dominating peak.

  14. Resonance method to produce a polarisation asymmetry in electron-positron storage rings

    SciTech Connect

    Toner, W.T.

    1988-01-01

    Pulsed solenoids of a few tens of ampere turns, operated in synchronism with the ..gamma..(g-2/2) 'th harmonic of the orbit period, can be used to prevent a stored electron beam from becoming polarised through the emission of synchrotron radiation. With such low fields it is easy to arrange that only some of the stored bunches are affected. This makes it possible to produce collisions between counter-rotating electrons and positrons stored in a single ring in which the electron and positron polarisations are not equal and opposite. 8 refs.

  15. On-chip temperature compensation in an integrated slot-waveguide ring resonator refractive index sensor array.

    PubMed

    Gylfason, Kristinn B; Carlborg, Carl Fredrik; Kaźmierczak, Andrzej; Dortu, Fabian; Sohlström, Hans; Vivien, Laurent; Barrios, Carlos A; van der Wijngaart, Wouter; Stemme, Göran

    2010-02-15

    We present an experimental study of an integrated slot-waveguide refractive index sensor array fabricated in silicon nitride on silica. We study the temperature dependence of the slot-waveguide ring resonator sensors and find that they show a low temperature dependence of -16.6 pm/K, while at the same time a large refractive index sensitivity of 240 nm per refractive index unit. Furthermore, by using on-chip temperature referencing, a differential temperature sensitivity of only 0.3 pm/K is obtained, without individual sensor calibration. This low value indicates good sensor-to-sensor repeatability, thus enabling use in highly parallel chemical assays. We demonstrate refractive index measurements during temperature drift and show a detection limit of 8.8 x 10-6 refractive index units in a 7 K temperature operating window, without external temperature control. Finally, we suggest the possibility of athermal slot-waveguide sensor design.

  16. Comparison of birefringent electric split-ring resonator and meanderline structures as quarter-wave plates at terahertz frequencies.

    PubMed

    Strikwerda, Andrew C; Fan, Kebin; Tao, Hu; Pilon, Daniel V; Zhang, Xin; Averitt, Richard D

    2009-01-05

    We have fabricated a quarter-wave plate from a single layer of birefringent electric split-ring resonators (ELC). For comparison, an appropriately scaled double layer meanderline structure was fabricated. At the design frequency of 639 GHz, the ELC structure achieves 99.9% circular polarization while the meanderline achieves 99.6%. The me-anderline displays a larger bandwidth of operation, attaining over 99% circular polarization from 615 - 743 GHz, while the ELC achieves 99% from 626 - 660 GHz. However, both are broad enough for use with CW sources making ELCs a more attractive choice due to the ease of fabrication. Both samples are free standing with a total thickness of 70 microm for the meanderline structure and a mere 20 microm for the ELC highlighting the large degree of birefringence exhibited with metamaterial structures.

  17. Lab-in-a-tube: on-chip integration of glass optofluidic ring resonators for label-free sensing applications.

    PubMed

    Harazim, Stefan M; Bolaños Quiñones, Vladimir A; Kiravittaya, Suwit; Sanchez, Samuel; Schmidt, Oliver G

    2012-08-07

    The fabrication of tubular rolled-up optofluidic ring resonators (RU-OFRRs) based on glass (SiO(2)) material with high quality factors is reported. A novel methodology combining lab-on-a-chip fabrication methods and rolled-up nanotech is presented for the fabrication of fully integrated tubular optofluidic sensors. The microfluidic integration of several RU-OFRRs on one chip is solved by enclosing the microtubes with a patterned robust SU-8 polymeric matrix. A viewport on each microtube enables exact excitation and monitoring of whispering gallery modes with a photoluminescence spectroscopy system under constant ambient conditions, while exchanging the content of the RU-OFRR with liquids of different refractive indices. The refractrometric sensor capabilities are investigated regarding signal stability, sensitivity and reliability. The sensitivity of the integrated RU-OFRR, which is the response of the modes to the change in refractive index of the liquid, is up to 880 nm/refractive index units (RIU).

  18. Generation of circularly polarized waves based on electro inductive-wave (EIW) coupling to chains of complementary split ring resonators

    NASA Astrophysics Data System (ADS)

    Ortiz, Noelia; Crespo, Gonzalo; Iriarte, Juan Carlos; Falcone, Francisco

    2016-11-01

    In this work, Electro-Inductive wave (EIW) propagation phenomenon is employed in order to introduce a polarization rotation capability in a rectangular patch antenna. The EIW propagation phenomenon is used to master the field distribution within the rectangular patch, and hence, to change the polarization of a patch antenna, which is shown to change from linear to circular polarization. EIW propagation is supported by a chain of Complementary Split Ring Resonators printed in a rectangular patch antenna at specific locations. This principle of operation is demonstrated with the design, fabrication, and measurement of antenna prototypes. Experimental results confirm numerical analysis, providing a simple antenna configuration with polarization variation capabilities, extendable to multiple configurations, in radiated waves as well as in guided wave phenomena.

  19. Pulse advancement and delay in an integrated-optical two-port ring-resonator circuit: direct experimental observations.

    PubMed

    Uranus, H P; Zhuang, L; Roeloffzen, C G H; Hoekstra, H J W M

    2007-09-01

    We report experimental observations of the negative-group-velocity (v(g)) phenomenon in an integrated-optical two-port ring-resonator circuit. We demonstrate that when the v(g) is negative, the (main) peak of output pulse appears earlier than the peak of a reference pulse, while for a positive v(g), the situation is the other way around. We observed that a pulse splitting phenomenon occurs in the neighborhood of the critical-coupling point. This pulse splitting limits the maximum achievable delay and advancement of a single device as well as facilitating a smooth transition from highly advanced to highly delayed pulse, and vice versa, across the critical-coupling point.

  20. Detection of CD4+ and CD8 + T-lymphocytes with the optofluidic ring resonator (OFRR) biosensor

    NASA Astrophysics Data System (ADS)

    Gohring, John T.; Fan, Xudong

    2009-05-01

    We have demonstrated the use of the Opto-Fluidic ring resonator (OFRR) to achieve the label-free detection of CD4+ and CD8+ T-Lymphocytes. The OFRR sensing technology combines microfluidics and optical sensing in a small platform that achieves rapid detection. In this work, white blood cells were obtained from healthy blood and the concentration altered to reflect CD4 and CD8 concentrations of HIV infected individuals. The OFRR was modified to effectively capture these receptors located on T-Lymphocytes and obtain a sensing signal through interaction with an evanescent field. Results show isolation of CD4+ and CD8+ T-Lymphocytes at medically significant levels. This work will lead to a device that can provide a CD4 and CD8 count to measure HIV progression in a low cost sensing setup.

  1. Ka-band propagation characteristics of microstrip lines on GaAs substrates at cryogenic temperatures

    NASA Technical Reports Server (NTRS)

    Romanofsky, R. R.; Martinez, J. C.; Viergutz, B. J.; Bhasin, K. B.

    1990-01-01

    Effective permitivity and loss characteristics of gold microstrip lines on GaAs substrates were obtained by characterizing GaAs linear resonators at cryogenic temperatures (300 to 20 K) from 30-40 GHz. A slight decrease in effective permittivity and a significant reduction in loss were observed with lower temperatures.

  2. A microstrip detector with delay line readout

    SciTech Connect

    Barbosa, A.F. , BP 220, 38043 Grenoble CNPq Riekel, C.; Wattecamps, P. , BP 220, 38043 Grenoble )

    1992-01-01

    Principal limitations of position sensitive gasfilled detectors for x-ray synchrotron radiation applications are the counting rate and the positional resolution. Improvements in both areas are expected with microstrip technology. First results of a linear position sensitive microstrip detector with delay line readout are shown, and the possibility to achieve two-dimensional localization is evaluated.

  3. Nuclear Quadrupole Resonance (NQR) Method and Probe for Generating RF Magnetic Fields in Different Directions to Distinguish NQR from Acoustic Ringing Induced in a Sample

    DTIC Science & Technology

    1997-08-01

    77,719 TITLE OF THE INVENTION NUCLEAR QUADRUPOLE RESONANCE ( NQR ) METHOD AND PROBE FOR GENERATING RF MAGNETIC FIELDS IN DIFFERENT DIRECTIONS TO...DISTINGUISH NQR FROM ACOUSTIC RINGING INDUCED IN A SAMPLE BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a...nuclear quadrupole 15 resonance ( NQR ) method and probe for generating RF magnetic fields in different directions towards a sample. More specifically

  4. Compact circularly polarized truncated square ring slot antenna with suppressed higher resonances

    PubMed Central

    Sabran, Mursyidul Idzam; Leow, Chee Yen; Soh, Ping Jack; Chew, Beng Wah; Vandenbosch, Guy A. E.

    2017-01-01

    This paper presents a compact circularly polarized (CP) antenna with an integrated higher order harmonic rejection filter. The proposed design operates within the ISM band of 2.32 GHz– 2.63 GHz and is suitable for example for wireless power transfer applications. Asymmetrical truncated edges on a square ring create a defected ground structure to excite the CP property, simultaneously realizing compactness. It offers a 50.5% reduced patch area compared to a conventional design. Novel stubs and slot shapes are integrated in the transmission line to reduce higher (up to the third) order harmonics. The proposed prototype yields a -10 dB reflection coefficient (S11) impedance bandwidth of 12.53%, a 3 dB axial ratio bandwidth of 3.27%, and a gain of 5.64 dBi. Measurements also show good agreement with simulations. PMID:28192504

  5. Superstrate effects on slot-coupled microstrip antennas

    NASA Astrophysics Data System (ADS)

    Huang, Chang-Hsiu; Hsu, Powen

    1991-09-01

    An analysis for studying the superstrate (cover) effects on the slot-coupled microstrip antennas is presented. The approach is based on the reciprocity theorem and uses the grounded double- and single-layer dielectric slab Green's functions in a moment method solution for the unknown slot fields and patch currents. From these fields and currents, various characteristics of the antenna can be extracted, such as the radiation efficiency, directivity, input impedance, and resonant frequency. Numerical calculations showing superstrate effects on these antenna characteristics are presented. The input matches obtained from proper adjustment of the slot and patch dimensions are discussed.

  6. Public key suppression and recovery using a PANDA ring resonator for high security communication

    NASA Astrophysics Data System (ADS)

    Juleang, Pakorn; Phongsanam, Prapas; Mitatha, Somsak; Yupapin, Preecha P.

    2011-03-01

    An interesting security technique that uses the dark-bright soliton conversion control within the microring resonator is proposed. The obtained outputs for a dark-bright soliton dynamic state can be controlled and used to form the public key suppression for communication security application. However, a good design should be possible to be fabricated; therefore, by using the parameters based on the practical device parameters, the simulation results obtained have shown that the proposed system can indeed be achieved. The public key suppression and public key recovery can be used in a highly secure communication system and has potential applications in optical cryptography.

  7. D0 silicon microstrip tracker

    SciTech Connect

    Burdin, Sergey

    2005-11-01

    The D0 Run II silicon microstrip tracker (SMT) has 3 square meters of Si area. There are 792,576 channels read out by 6192 SVXIIe chips on 912 read out modules. The SMT provides track and vertex reconstruction capabilities over the full pseudorapidity coverage of the D0 detector. The full detector has been running successfully since April 2002. This presentation covers the experience in commissioning and operating, the recent electronics upgrade which improved stability of the SMT and estimates of the radiation damage.

  8. Design of an inductively decoupled microstrip array at 9.4 T.

    PubMed

    Wu, Bing; Zhang, Xiaoliang; Qu, Peng; Shen, Gary X

    2006-09-01

    By independent control of the phases and amplitudes of its elements, the microstrip transmission-line array can mitigate sample-induced RF non-uniformities, and has been widely used as the transceiver in parallel imaging applications. One major challenge in implementing the microstrip array is the reduction of mutual coupling among individual elements. The low-input impedance preamplifier is commonly used for the decoupling purpose. However, it is impractical in the transceiver array design. Although interconnecting capacitors can be utilized to reduce the mutual coupling, they only efficiently work for the neighbor elements. In addition, this approach is impractical at fields higher than 300 MHz, in which the required decoupling capacitance is commonly less than 0.5 pF. We propose a novel decoupling approach by using decoupling inductors in this study. Due to the fact that the decoupling inductance is independent of the resonant frequency, the microstrip arrays can be well decoupled at ultra-high fields. To verify the proposed approach, an eight-channel microstrip array is fabricated and tested at 9.4 T. For this prototype, couplings between elements are significantly reduced by using the interconnecting inductors. The phantom experiment shows that the inductively decoupled microstrip array has good parallel imaging performance.

  9. Dispersion in Nb microstrip transmission lines at submillimeter wave frequencies

    NASA Technical Reports Server (NTRS)

    Javadi, H. H. S.; Mcgrath, W. R.; Bumble, B.; Leduc, H. G.

    1992-01-01

    We have measured the effects of dispersion on the resonant mode frequencies of open-ended Nb-SiO(x)-Nb microstrip transmission lines over a frequency range from 50 to 800 GHz. Submicron Nb/Al-AlOx/Nb Josephson junctions were used as both voltage-controlled oscillators and detectors to sample the high order modes of the resonators. The resonator modes are equally spaced up to about 550 GHz where the mode spacing start to decrease gradually to a minimum above the gap frequency of about 700 GHz and then increases. Results are in good agreement with the expected theoretical behavior based on the Mattis-Bardeen conductivity of the superconductor line.

  10. Low-voltage high-speed coupling modulation in silicon racetrack ring resonators.

    PubMed

    Yang, Rui; Zhou, Linjie; Zhu, Haike; Chen, Jianping

    2015-11-02

    We demonstrate a low-voltage high-speed modulator based on a silicon racetrack resonator with a tunable Mach-Zehnder interferometer coupler. Both static measurement and dynamic modulation experiment are carried out. The 3-dB electro-optic bandwidth is measured to be >30 GHz beyond the limit by the cavity photon lifetime. A 32 Gb/s on-off keying (OOK) modulation is realized under a peak-to-peak drive voltage as low as 0.4 V, and a 28 Gb/s binary phase-shift-keying (BPSK) modulation is realized with a drive voltage of 3 V. The low drive voltages results in low energy consumptions of ~13.3 fJ/bit and ~1.2 pJ/bit for OOK and BPSK modulations, respectively.

  11. Electro-optic directed XOR logic circuits based on parallel-cascaded micro-ring resonators.

    PubMed

    Tian, Yonghui; Zhao, Yongpeng; Chen, Wenjie; Guo, Anqi; Li, Dezhao; Zhao, Guolin; Liu, Zilong; Xiao, Huifu; Liu, Guipeng; Yang, Jianhong

    2015-10-05

    We report an electro-optic photonic integrated circuit which can perform the exclusive (XOR) logic operation based on two silicon parallel-cascaded microring resonators (MRRs) fabricated on the silicon-on-insulator (SOI) platform. PIN diodes embedded around MRRs are employed to achieve the carrier injection modulation. Two electrical pulse sequences regarded as two operands of operations are applied to PIN diodes to modulate two MRRs through the free carrier dispersion effect. The final operation result of two operands is output at the Output port in the form of light. The scattering matrix method is employed to establish numerical model of the device, and numerical simulator SG-framework is used to simulate the electrical characteristics of the PIN diodes. XOR operation with the speed of 100Mbps is demonstrated successfully.

  12. Combined Brillouin light scattering and microwave absorption study of magnon-photon coupling in a split-ring resonator/YIG film system

    NASA Astrophysics Data System (ADS)

    Klingler, S.; Maier-Flaig, H.; Gross, R.; Hu, C.-M.; Huebl, H.; Goennenwein, S. T. B.; Weiler, M.

    2016-08-01

    Microfocused Brillouin light scattering (BLS) and microwave absorption (MA) are used to study magnon-photon coupling in a system consisting of a split-ring microwave resonator and an yttrium iron garnet (YIG) film. The split-ring resonator is defined by optical lithography and loaded with a 1 μm-thick YIG film grown by liquid phase epitaxy. BLS and MA spectra of the hybrid system are simultaneously recorded as a function of the applied magnetic field magnitude and microwave excitation frequency. Strong coupling of the magnon and microwave resonator modes is found with a coupling strength of geff /2π = 63 MHz. The combined BLS and MA data allow us to study the continuous transition of the hybridized modes from a purely magnonic to a purely photonic mode by varying the applied magnetic field and microwave frequency. Furthermore, the BLS data represent an up-conversion of the microwave frequency coupling to optical frequencies.

  13. Microstrip antenna on tunable substrate

    NASA Astrophysics Data System (ADS)

    Jose, K. A.; Varadan, Vijay K.; Varadan, Vasundara V.; Mohanan, P.

    1995-05-01

    The tunable patch antenna configurations are becoming popular and attractive in many aspects. This was mainly due to the advent of ferrite thin film technology and tunable substrate materials. The integration of monolithic microwave circuits and antennas are becoming easy today. In the development of magnetic tuning of microstrip patch on ferrite substrate is presented by Rainville and Harackewiez. Radiation characteristics of such antennas are presented by Pozer. Band width and radiation characteristics of such tunable antennas are measured and compared. Usually the substrate losses are considered in the analysis and metallization losses are assumed to be ideal. The analysis of magnetic tunable radiator including metallization and ferrite substrate losses are presented. However, all such tuning and integration of circuits and antennas are mainly on ferrite substrate due to magnetic tuning. Recently, Varadan et al. established that the BaxSr1-xTiO3 series ferroelectric materials such as Barium Strontium Titanate (BST) are well suited for microwave phase shifter applications. It could be possible to change the dielectric constant of these materials more than 50% depending on the BST composition, by changing the applied bias voltage. Also, the porosity of BST can be controlled during processing to produce dielectric constants in the range of 15 to 1500, with some trade off in tunability. In this paper, we are presenting the possibility of designing a microstrip patch antenna on such tunable substrate. Such antennas are having the major advantage of electronic tunability and compact size.

  14. Design and fabrication of microstrip antenna arrays

    NASA Technical Reports Server (NTRS)

    1978-01-01

    A microstrip array project was conducted to demonstrate the feasibility of designing and fabricating simple, low cost, low sidelobe phased arrays with circular disk microstrip radiating elements. Design data were presented for microstrip elements and arrays including the effects of the protective covers, the mutual interaction between elements, and stripline feed network design. Low cost multilayer laminate fabrication techniques were also investigated. Utilizing this design data two C-band low sidelobe arrays were fabricated and tested: an eight-element linear and a sixty-four element planar array. These arrays incorporated stripline Butler matrix feed networks to produce a low sidelobe broadside beam.

  15. An experimental study of high Tc superconducting microstrip transmission lines at 35 GHz and the effect of film morphology

    NASA Technical Reports Server (NTRS)

    Chorey, C. M.; Bhasin, K. B.; Warner, J. D.; Josefowicz, J. Y.; Rensch, D. B.

    1991-01-01

    Microstrip transmission lines in the form of ring resonators were fabricated from a number of in-situ grown laser ablated films and post-annealed co-sputtered YBa2Cu3O(7-x) films. The properties of these resonators were measured at 35 GHz and the observed performance is examined in light of the critical temperature (Tc) and film thickness, and also the film morphology, which is different for the two deposition techniques. It is found that Tc is a major indicator of the film performance for each growth type, with film thickness becoming important as it decreases towards 1000 A. It is also found that the films with a mixed grain orientation (both a-axis and c-axis oriented grains) have poorer microwave properties as compared with the primarily c-axis oriented material. This is probably due to the significant number of grain boundaries between the different crystallites, which may act as superconducting weak links and contribute to the surface resistance.

  16. An experimental study of high Tc superconducting microstrip transmission lines at 35 GHz and the effect of film morphology

    NASA Technical Reports Server (NTRS)

    Chorey, C. M.; Bhasin, K. B.; Warner, J. D.; Josefowicz, J. Y.; Rensch, D. B.; Nieh, C. W.

    1990-01-01

    Microstrip transmission lines in the form of ring resonators were fabricated from a number of in-situ grown laser ablated films and post-annealed co-sputtered YBa2Cu3O(7-x) films. The properties of these resonators were measured at 35 GHz and the observed performance is examined in light of the critical temperature (Tc) and film thickness and also the film morphology which is different for the two deposition techniques. It is found that Tc is a major indicator of the film performance for each growth type with film thickness becoming important as it decreases towards 100 A. It is also found that the films with a mixed grain orientation (both a axis and c axis oriented grains) have poorer microwave properties as compared with the primarily c axis oriented material. This is probably due to the significant number of grain boundaries between the different crystallites, which may act as superconducting weak links and contribute to the surface resistance.

  17. Analysis of Stub Loaded Microstrip Patch Antennas

    NASA Technical Reports Server (NTRS)

    Bailey, M. C.; Deshpande, M. D.

    1997-01-01

    A microstrip patch antenna fed by a coaxial probe and reactively loaded by a open circuited microstrip line has been used previously to produce circular polarization[ l] and also as a building block for a series fed microstrip patch array [2]. Rectangular and circular patch antennas loaded with a microstrip stub were previously analyzed using the generalized Thevenin theorem [2,3]. In the Thevenin theorem approach, the mutual coupling between the patch current and the surface current on the stub was not taken into account. Also, the Thevenin theorem approach neglects continuity of current at the patch-stub junction. The approach in this present paper includes the coupling between the patch and stub currents as well as continuity at the patch-stub junction.

  18. Design of microstrip components by computer

    NASA Technical Reports Server (NTRS)

    Cisco, T. C.

    1972-01-01

    Development of computer programs for component analysis and design aids used in production of microstrip components is discussed. System includes designs for couplers, filters, circulators, transformers, power splitters, diode switches, and attenuators.

  19. Microstrip proportional counter development at MSFC

    NASA Technical Reports Server (NTRS)

    Fulton, M. A.; Kolodziejczak, J. J.; Ramsey, B. D.

    1992-01-01

    Microstrip detectors are an exciting new development in proportional counter design fabricated using integrated circuit-type photolithography techniques; they therefore offer very high spatial accuracy and uniformity. A development program is underway at NASA-Marshall to produce large-area microstrips for use in an X-ray detector balloon flight program and to investigate the general performance limits of these new devices. Microstrips tested so far have been fabricated both in-house using standard photolithographic techniques and by an outside contractor using electron beam technology. Various substrate materials have been tested along with different electrode configurations. The distributions of pickup on subdivided cathodes on both top and bottom surfaces of the microstrips are also being investigated for use as two-dimensional imaging detectors. Data from these tests in the development of a large-area device will be presented.

  20. Dissipative soliton resonance in a full polarization-maintaining fiber ring laser at different values of dispersion.

    PubMed

    Armas-Rivera, I; Cuadrado-Laborde, C; Carrascosa, A; Kuzin, E A; Beltrán-Pérez, G; Díez, A; Andrés, M V

    2016-05-02

    We investigated the dissipative solitons resonance in an ytterbium-doped fiber ring laser in which all the elements are polarization maintaining (PM). A semiconductor saturable absorber mirror was used as a mode-locker. The cavity included a normal dispersion single-mode fiber (SMF) and an anomalous dispersion photonic crystal fiber. The change of the length of the PM SMF allows the variation of the net-normal dispersion of the cavity in the range from 0.022 ps2 to 0.262 ps2. As the absolute value of the net-normal dispersion increases from 0.022 ps2 to 0.21 ps2, a square-shaped single pulse transformed to a single right-angle trapezoid-shaped pulse, and, at the dispersion of 0.262 ps2, to multiple right-angle trapezoid-shaped pulses, per round-trip.

  1. Microstrip monopulse antenna for land mobile communications

    NASA Technical Reports Server (NTRS)

    Garcia, Q.; Martin, C.; Delvalle, J. C.; Jongejans, A.; Rinous, P.; Travers, M. N.

    1993-01-01

    Low cost is one of the main requirements in a communication system suitable for mass production, as it is the case for satellite land mobile communications. Microstrip technology fulfills this requirement which must be supported by a low cost tracking system design. The tradeoff led us to a prototype antenna composed of microstrip patches based on electromechanical closed-loop principle; the design and the results obtained are described.

  2. Single- and double-sided sensor applications of metamaterials based on square-ring and diamond resonators for terahertz region

    NASA Astrophysics Data System (ADS)

    Shawky, Najlaa; Adnan Taha, Salah Al-Deen; Altan, Hakan; Sabah, Cumali

    2017-03-01

    This study investigates the sensing applications of metamaterial (MTM) structures in the terahertz (THz) region and is based on a broadside-coupled diamond and square-ring resonator (DSRR) structures. The resonators are designed and simulated as sensors in detail. Compared with single-sided sensors, the sensing capability of double-sided sensors provide an enhancement with respect to the sensitivity. To analyze the structure as sensor, the changes in the transmission resonance are investigated as a function of the permittivity and thickness of overlayer for the single- and double-sided MTM. The results demonstrate that this design can provide good sensitivity when sensing the chemical or biological agents that are resonant in the terahertz region of the electromagnetic spectrum. These types of designs can be employed in the many sensing applications that are of interest in the THz region.

  3. Hybrid perturbation scheme for wide beamwidth circularly polarized stacked patch microstrip antenna for satellite communication

    NASA Astrophysics Data System (ADS)

    Hossain, Mohammad Shakawat

    Circularly polarized microstrip antennas are popular for satellite communications due to their circularly polarized orientation. They are used frequently in modern day satellite communication. In order to achieve wide angular coverage in satellite communication, a wide beamwidth is required from the antenna. Traditional single layer microstrip antenna inherently demonstrates low angular beamwidth of approximately 600 to 800and thereby lacks wide angular coverage when used for satellite communication. The objective of this thesis is to design a single-fed stacked microstrip antenna using different perturbation techniques in order to achieve a wide angular beamwidth. This thesis presents a new design for a circularly polarized antenna based on the hybrid perturbation scheme. First, a method of stacked patch-ring with negative perturbation was used to generate a significantly larger beamwidth of 1060. The axial ratio (AR) bandwidth obtained is also significantly larger compared to the case when square rings are used as parasitic and driven rings with a single feed. A simulated impedance bandwidth (S11< - 10 dB) of 16%, 3 dB AR bandwidth of 8% and a peak gain of 8.65 dBic are obtained from this design. Next, a new design of stacked hybrid antenna is presented, which uses hybrid perturbations to generate circular polarization radiation. An enhanced beamwidth of 1260 was obtained. The simulation results are confirmed by the measured results.

  4. Non-water-suppressed short-echo-time magnetic resonance spectroscopic imaging using a concentric ring k-space trajectory.

    PubMed

    Emir, Uzay E; Burns, Brian; Chiew, Mark; Jezzard, Peter; Thomas, M Albert

    2017-03-08

    Water-suppressed MRS acquisition techniques have been the standard MRS approach used in research and for clinical scanning to date. The acquisition of a non-water-suppressed MRS spectrum is used for artefact correction, reconstruction of phased-array coil data and metabolite quantification. Here, a two-scan metabolite-cycling magnetic resonance spectroscopic imaging (MRSI) scheme that does not use water suppression is demonstrated and evaluated. Specifically, the feasibility of acquiring and quantifying short-echo (TE  = 14 ms), two-dimensional stimulated echo acquisition mode (STEAM) MRSI spectra in the motor cortex is demonstrated on a 3 T MRI system. The increase in measurement time from the metabolite-cycling is counterbalanced by a time-efficient concentric ring k-space trajectory. To validate the technique, water-suppressed MRSI acquisitions were also performed for comparison. The proposed non-water-suppressed metabolite-cycling MRSI technique was tested for detection and correction of resonance frequency drifts due to subject motion and/or hardware instability, and the feasibility of high-resolution metabolic mapping over a whole brain slice was assessed. Our results show that the metabolite spectra and estimated concentrations are in agreement between non-water-suppressed and water-suppressed techniques. The achieved spectral quality, signal-to-noise ratio (SNR) > 20 and linewidth <7 Hz allowed reliable metabolic mapping of five major brain metabolites in the motor cortex with an in-plane resolution of 10 × 10 mm(2) in 8 min and with a Cramér-Rao lower bound of less than 20% using LCModel analysis. In addition, the high SNR of the water peak of the non-water-suppressed technique enabled voxel-wise single-scan frequency, phase and eddy current correction. These findings demonstrate that our non-water-suppressed metabolite-cycling MRSI technique can perform robustly on 3 T MRI systems and within a clinically feasible acquisition time.

  5. Stepped impedance resonators for high-field magnetic resonance imaging.

    PubMed

    Akgun, Can E; DelaBarre, Lance; Yoo, Hyoungsuk; Sohn, Sung-Min; Snyder, Carl J; Adriany, Gregor; Ugurbil, Kamil; Gopinath, Anand; Vaughan, J Thomas

    2014-02-01

    Multi-element volume radio-frequency (RF) coils are an integral aspect of the growing field of high-field magnetic resonance imaging. In these systems, a popular volume coil of choice has become the transverse electromagnetic (TEM) transceiver coil consisting of microstrip resonators. In this paper, to further advance this design approach, a new microstrip resonator strategy in which the transmission line is segmented into alternating impedance sections, referred to as stepped impedance resonators (SIRs), is investigated. Single-element simulation results in free space and in a phantom at 7 T (298 MHz) demonstrate the rationale and feasibility of the SIR design strategy. Simulation and image results at 7 T in a phantom and human head illustrate the improvements in a transmit magnetic field, as well as RF efficiency (transmit magnetic field versus specific absorption rate) when two different SIR designs are incorporated in 8-element volume coil configurations and compared to a volume coil consisting of microstrip elements.

  6. Stepped Impedance Resonators for High Field Magnetic Resonance Imaging

    PubMed Central

    Akgun, Can E.; DelaBarre, Lance; Yoo, Hyoungsuk; Sohn, Sung-Min; Snyder, Carl J.; Adriany, Gregor; Ugurbil, Kamil; Gopinath, Anand; Vaughan, J. Thomas

    2014-01-01

    Multi-element volume radio-frequency (RF) coils are an integral aspect of the growing field of high field magnetic resonance imaging (MRI). In these systems, a popular volume coil of choice has become the transverse electromagnetic (TEM) multi-element transceiver coil consisting of microstrip resonators. In this paper, to further advance this design approach, a new microstrip resonator strategy in which the transmission line is segmented into alternating impedance sections referred to as stepped impedance resonators (SIRs) is investigated. Single element simulation results in free space and in a phantom at 7 tesla (298 MHz) demonstrate the rationale and feasibility of the SIR design strategy. Simulation and image results at 7 tesla in a phantom and human head illustrate the improvements in transmit magnetic field, as well as, RF efficiency (transmit magnetic field versus SAR) when two different SIR designs are incorporated in 8-element volume coil configurations and compared to a volume coil consisting of microstrip elements. PMID:23508243

  7. Electrically Small Microstrip Quarter-Wave Monopole Antennas

    NASA Technical Reports Server (NTRS)

    Young, W. Robert

    2004-01-01

    with the patch above one-third of the radial distance from the center. The modified feed configuration of the innovative approach is an inductive-short-circuit configuration that provides impedance matching and that has been used for many years on other antennas but not on microstrip-style monopole antennas. In this configuration, the pin is connected to both the conductive patch and the ground plane. As before, the shield of the coaxial cable is connected to the ground plane, but now the central conductor is connected to a point on the pin between the ground plane and the conductive plate (see figure). The location of the connection point on the pin is chosen so that together, the inductive short circuit and the conductive plate or patch act as components of a lumped-element resonant circuit that radiates efficiently at the resonance frequency and, at the resonance frequency, has an impedance that matches that of the coaxial cable. It should be noted that the innovative design entails two significant disadvantages. One disadvantage is that the frequency bandwidth for efficient operation is only about 1/20 to 1/15 that of a whip antenna designed for the same nominal frequency. The other disadvantage is that the estimated gain is between 3-1/2 and 4-1/2 dB below that of the whip antenna. However, if an affected radio-communication system used only a few adjacent frequency channels and the design of the components of the system other than the antenna provided adequate power or gain margin, then these disadvantages could be overcome.

  8. Broadband Microstrip-to-Coplanar Strip Double-Y Balun

    NASA Technical Reports Server (NTRS)

    Venkatesan, Jaikrishna

    2008-01-01

    A new version of the double-Y balun, transitioning from an unbalanced microstrip to a balanced coplanar strip (CPS) line, has been designed to feed a complementary spiral antenna with an input impedance of 100 Omega. The new double-Y balun transitions from a microstrip line with truncated ground plane to a CPS line. The balun does not employ CPW lines; hence, CPW bridges are not required at the junction. In addition, the balun does not exhibit CPW parasitic resonances, thereby improving passband performance. The new version of the double-Y balun is designed to feed a complementary spiral antenna. Panels on the right illustrate an expanded view of the balun junction. Preliminary voltage standing-wave ratio (VSWR) and insertion loss data are illustrated. Measured data were compared with numerical results computed using Momentum. It is seen that the balun exhibits a VSWR of less than 1.5 from 400 MHz to 8 GHz and a VSWR of less than 1.8 up to 13 GHz. The VSWR can be reduced further by reducing reflections from the balun junction and load resistor. Also, the balun is seen to exhibit an insertion loss of less than 1.5 dB up to 12 GHz. Further work involves characterizing the balun's performance when feeding a complementary spiral antenna.

  9. A Microstrip Reflect Array Using Crossed Dipoles

    NASA Technical Reports Server (NTRS)

    Pozar, David M.; Targonski, Stephen D.

    1998-01-01

    Microstrip reflect arrays offer a flat profile and light weight, combined with many of the electrical characteristics of reflector antennas. Previous work [1]-[7] has demonstrated a variety of microstrip reflect arrays, using different elements at a range of frequencies. In this paper we describe the use of crossed dipoles as reflecting elements in a microstrip reflectarray. Theory of the solution will be described, with experimental results for a 6" square reflectarray operating at 28 GHz. The performance of crossed dipoles will be directly compared with microstrip patches, in terms of bandwidth and loss. We also comment on the principle of operation of reflectarray elements, including crossed dipoles, patches of variable length, and patch elements with tuning stubs. This research was prompted by the proposed concept of overlaying a flat printed reflectarray on the surface of a spacecraft solar panel. Combining solar panel and antenna apertures in this way would lead to a reduction in weight and simpler deployment, with some loss of flexibility in independently pointing the solar panel and the antenna. Using crossed dipoles as reflectarray elements will minimize the aperture blockage of the solar cells, in contrast to the use of elements such as microstrip patches.

  10. High-efficiency frequency upconversion of 1.5 μm laser based on a doubly resonant external ring cavity with a low finesse for signal field

    NASA Astrophysics Data System (ADS)

    Tan, Wei; Qiu, Xiaodong; Zhao, Gang; Jia, Mengyuan; Ma, Weiguang; Yan, Xiaojuan; Dong, Lei; Zhang, Lei; Tong, Zhaomin; Yin, Wangbao; Feng, Xiaoxia; Xiao, Liantuan; Axner, Ove; Jia, Suotang

    2017-02-01

    A doubly resonant external ring cavity with a low finesse for the signal field is used to improve the frequency upconversion efficiency of a weak 1583 nm signal laser to 636 nm by mixing with a resonance power enhanced 1064 nm pump laser in a 25 mm periodically poled lithium niobate crystal. The process of frequency upconversion is described and optimized by the doubly resonant cavity-enhanced sum frequency generation theory under the condition of undepleted pump approximation. By selecting the suitable reflectivity of the signal input mirror and the incident pump power, a cavity-enhanced frequency conversion efficiency of 94.6% was obtained for signal powers up to 25 mW with an input pump power of 780 mW.

  11. Electric surface current model for the analysis of microstrip antennas with application to rectangular elements

    NASA Astrophysics Data System (ADS)

    Perlmutter, P.; Shtrikman, S.; Treves, D.

    1985-03-01

    An approach to the analysis of microstrip antennas which is applicable also to relatively thick substrates using the relevant Green's function is presented. The Green's function is derived and closed form expressions for various antenna characteristics which explicity take into account the presence of the dielectric material are obtained in terms of the electric surface current density. For rectangular microstrip elements near resonance the current distribution is approximated using lossless transmission line analysis, thus enabling the complete evaluation of the characteristics of the element near resonance. The results obtained in this approach for the radiation resistance, surface wave resistance, radiation pattern, directivity, and bandwidth are presented in a detailed set of graphs for a representative set of parameters.

  12. A microwave resonator integrated on a polymer microfluidic chip.

    PubMed

    Kiss, S Z; Rostas, A M; Heidinger, L; Spengler, N; Meissner, M V; MacKinnon, N; Schleicher, E; Weber, S; Korvink, J G

    2016-09-01

    We describe a novel stacked split-ring type microwave (MW) resonator that is integrated into a 10mm by 10mm sized microfluidic chip. A straightforward and scalable batch fabrication process renders the chip suitable for single-use applications. The resonator volume can be conveniently loaded with liquid sample via microfluidic channels patterned into the mid layer of the chip. The proposed MW resonator offers an alternative solution for compact in-field measurements, such as low-field magnetic resonance (MR) experiments requiring convenient sample exchange. A microstrip line was used to inductively couple MWs into the resonator. We characterised the proposed resonator topology by electromagnetic (EM) field simulations, a field perturbation method, as well as by return loss measurements. Electron paramagnetic resonance (EPR) spectra at X-band frequencies were recorded, revealing an electron-spin sensitivity of 3.7·10(11)spins·Hz(-1/2)G(-1) for a single EPR transition. Preliminary time-resolved EPR experiments on light-induced triplet states in pentacene were performed to estimate the MW conversion efficiency of the resonator.

  13. A microwave resonator integrated on a polymer microfluidic chip

    NASA Astrophysics Data System (ADS)

    Kiss, S. Z.; Rostas, A. M.; Heidinger, L.; Spengler, N.; Meissner, M. V.; MacKinnon, N.; Schleicher, E.; Weber, S.; Korvink, J. G.

    2016-09-01

    We describe a novel stacked split-ring type microwave (MW) resonator that is integrated into a 10 mm by 10 mm sized microfluidic chip. A straightforward and scalable batch fabrication process renders the chip suitable for single-use applications. The resonator volume can be conveniently loaded with liquid sample via microfluidic channels patterned into the mid layer of the chip. The proposed MW resonator offers an alternative solution for compact in-field measurements, such as low-field magnetic resonance (MR) experiments requiring convenient sample exchange. A microstrip line was used to inductively couple MWs into the resonator. We characterised the proposed resonator topology by electromagnetic (EM) field simulations, a field perturbation method, as well as by return loss measurements. Electron paramagnetic resonance (EPR) spectra at X-band frequencies were recorded, revealing an electron-spin sensitivity of 3.7 ·1011spins ·Hz - 1 / 2G-1 for a single EPR transition. Preliminary time-resolved EPR experiments on light-induced triplet states in pentacene were performed to estimate the MW conversion efficiency of the resonator.

  14. A spectrum domain analysis for the microstrip patch antenna loaded by conducting posts

    NASA Astrophysics Data System (ADS)

    Zhang, W.-X.; Cheng, C.-H.

    Some samples of microstrip patch antennas, loaded or unloaded, with rectangular or equilateral triangle patches are analyzed and computed using the moment method and the spectrum domain method (SDM). A flexible technique for using SDM to analyze a perpendicular current in layered structures is introduced, and an integration technique to improve the convergence is suggested. The results show that loading posts cause a decrease rather than an increase in the resonant frequency.

  15. IRAS observations show that the Earth is embedded in a solar ring of asteroidal dust particles in resonant lock with the planet

    NASA Technical Reports Server (NTRS)

    Dermott, Stanley F.; Jayaraman, S.; Xu, Y.-L.; Liou, J.-C.

    1994-01-01

    We have analyzed all the infrared observations of the zodiacal cloud obtained in 1983 by the Infrared Astronomical Satellite (IRAS) and shown that when viewed at a constant elongation angle of 90 degrees, the elliptic brightness of the cloud is systematically greater by approx. 3 percent in the trailing direction than in the leading direction. This asymmetry is observed at all times of the year and in all three of the IRAS wavebands in which the zodiacal cloud is clearly observed. The orbits of cometary particles are highly eccentric and these particles are unlikely to be trapped in corotational resonances. Thus, the IRAS observations are evidence that the Earth is embedded in a ring of asteroidal particles. Similar rings are expected to be associated with Mars and Venus. The existence of asteroidal families and their associated dust bands (also discovered by IRAS) are evidence that the asteroid belt is a significant and maybe the dominant source of dust in the zodiacal cloud. These new observations give quantitative information both on the rate of transport of asteroidal dust to the Earth and on the rate of grinding down of the asteroid belt. Without resonant trapping most dust particles spiral past the Earth without striking the planet. However, most particles trapped in resonances are released from these resonances due to close encounter with the Earth. Thus, the ring may act as a funnel through which asteroidal particles are deposited in the Earth's atmosphere. This could have implications for the efficiency of the transport of carbonaceous material from the asteroid belt to the Earth and for the origin of life on the planet.

  16. Impedance properties of circular microstrip antenna

    NASA Technical Reports Server (NTRS)

    Deshpande, M. D.; Bailey, M. C.

    1983-01-01

    A moment method solution to the input impedance of a circular microstrip antenna excited by either a microstrip feed or a coaxial probe is presented. Using the exact dyadic Green's function and the Fourier transform the problem is formulated in terms of Richmond's reaction integral equation from which the unknown patch current can be solved for. The patch current is expanded in terms of regular surface patch modes and an attachment mode (for probe excited case) which insures continuity of the current at probe/patch junction, proper polarization and p-dependance of patch current in the vicinity of the probe. The input impedance of a circular microstrip antenna is computed and compared with earlier results. Effect of attachment mode on the input impedance is also discussed.

  17. DWDM channel spacing tunable optical TDM carrier from a mode-locked weak-resonant-cavity Fabry-Perot laser diode based fiber ring.

    PubMed

    Peng, Guo-Hsuan; Chi, Yu-Chieh; Lin, Gong-Ru

    2008-08-18

    A novel optical TDM pulsed carrier with tunable mode spacing matching the ITU-T defined DWDM channels is demonstrated, which is generated from an optically injection-mode-locked weak-resonant-cavity Fabry-Perot laser diode (FPLD) with 10%-end-facet reflectivity. The FPLD exhibits relatively weak cavity modes and a gain spectral linewidth covering >33.5 nm. The least common multiple of the mode spacing determined by both the weak-resonant-cavity FPLD and the fiber-ring cavity can be tunable by adjusting length of the fiber ring cavity or the FPLD temperature to approach the desired 200GHz DWDM channel spacing of 1.6 nm. At a specific fiber-ring cavity length, such a least-common- multiple selection rule results in 12 lasing modes between 1532 and 1545 nm naturally and a mode-locking pulsewidth of 19 ps broadened by group velocity dispersion among different modes. With an additional intracavity bandpass filter, the operating wavelength can further extend from 1520 to 1553.5 nm. After channel filtering, each selected longitudinal mode gives rise to a shortened pulsewidth of 12 ps due to the reduced group velocity dispersion. By linear dispersion compensating with a 55-m long dispersion compensation fiber (DCF), the pulsewidth can be further compressed to 8 ps with its corresponding peak-to-peak chirp reducing from 9.7 to 4.3 GHz.

  18. Strip and microstrip line periodic heterogeneities

    NASA Astrophysics Data System (ADS)

    Lerer, A. M.; Lerer, B. M.; Ryazanov, V. D.; Sledkov, V. A.

    1985-04-01

    A quasistatic method is described for analyzing periodic heterogeneities in single and coupled strip lines and microstrip lines. An ALGOL program on a BESM-6 computer calculated the running inductance and capacitance, wave impedances and delay coefficients for single and coupled strip lines and microstrip lines with periodic heterogeneities of arbitrary form. The analyzed quantities are investigated as a function of distance (from side shield to the strip), number of terms in the series and number of approximated functions. The method demonstrates good convergence and requires little machine time and results were verified experimentally.

  19. Propagation characteristics of superconducting microstrip lines

    SciTech Connect

    Mao, S.G.; Ke, J.Y.; Chen, C.H.

    1996-01-01

    The modified spectral-domain approach is applied to study the propagation characteristics of high temperature superconducting microstrip lines whose signal strip and ground plane are of arbitrary thickness. In this study, numerical results for effective dielectric constant, attenuation constant, and strip current distribution are presented to discuss the effects due to frequency, temperature, strip thickness, and substrate loss tangent. In particular, the conductor and dielectric attenuation constants of superconducting microstrip line are depicted separately to discuss the mechanism of the line losses. A comparison with published theoretical and experimental results is also included to check the accuracy of the new approach`s results.

  20. Multilayer Microstrip Slot And Dipole Array Antenna

    NASA Technical Reports Server (NTRS)

    Tulintseff, Ann N.

    1994-01-01

    Multilayer antenna structure contains interleaved linear subarrays of microstrip dipole and slot radiating antenna elements to provide compact, dual-band antenna. Structure also contains associated microstrip transmission lines, plus high-power amplifiers for transmission and low-noise amplifiers for reception. Overall function is to transmit in horizontal polarization at frequency of 29.634 GHz and receive in vertical polarization at 19.914 GHz, in direction 44 degrees from broadside to antenna. Antenna structure is part of apparatus described in "Steerable K/Ka-band Antenna for Land-Mobile Satellite Applications," NPO-18772.

  1. Bird Face Microstrip Printed Monopole Antenna Design for Ultra Wide Band Applications

    NASA Astrophysics Data System (ADS)

    Hossain, Mohammad Jakir; Faruque, Mohammad Rashed Iqbal; Islam, Md. Moinul; Islam, Mohammad Tariqul; Rahman, Md. Atiqur

    2016-11-01

    In this paper, a novel bird face microstrip printed monopole ultra-wideband (UWB) antenna is investigated. The proposed compact antenna consists of a ring-shaped with additional slot and slotted ground plane on FR4 material. The overall electrical dimension of the proposed antenna is 0.25 λ×0.36 λ×0.016 λ and is energized by microstrip feed line. The Computer Simulation Technology (CST) and the High Frequency Structural Simulator (HFSS) is applied in this analysis. The impedance bandwidth of the monopole antenna cover 3.1-12.3 GHz (9.2 GHz, BW) frequency range. The messurement displayed that the designed antenna achieved excellent gain and stable omnidirectional radiation patterns within the UWB. The maximum gain of 6.8 dBi and omnidirectional radiation pattern makes the proposed antenna that is suitable for UWB systems.

  2. Research and analysis of patch shape on microstrip patch antenna

    NASA Astrophysics Data System (ADS)

    Ji, Ai-guo; Wang, Peng

    2017-01-01

    The shape of the radiating patch in the microstrip patch antenna is one of the many factors that affect the performance of the microstrip antenna.In this paper, on the premise of center frequency of 2.45 GHz, rectangular, circular and triangular microstrip patch antennas are designed and simulated respectively.The simulation results of the three microstrip patch antenna are analyzed, such as feed point position, return loss and radiation patterns.The influence of the shape of the radiation patch on the impedance bandwidth, gain and directivity of microstrip antennas is discussed.The simulation results show that the comprehensive performance of rectangular microstrip patch antenna is better than the other two, the comprehensive performance of triangular microstrip patch antenna is poor.

  3. A packaged optical slot-waveguide ring resonator sensor array for multiplex label-free assays in labs-on-chips.

    PubMed

    Carlborg, C F; Gylfason, K B; Kaźmierczak, A; Dortu, F; Bañuls Polo, M J; Maquieira Catala, A; Kresbach, G M; Sohlström, H; Moh, T; Vivien, L; Popplewell, J; Ronan, G; Barrios, C A; Stemme, G; van der Wijngaart, W

    2010-02-07

    We present the design, fabrication, and characterisation of an array of optical slot-waveguide ring resonator sensors, integrated with microfluidic sample handling in a compact cartridge, for multiplexed real-time label-free biosensing. Multiplexing not only enables high throughput, but also provides reference channels for drift compensation and control experiments. Our use of alignment tolerant surface gratings to couple light into the optical chip enables quick replacement of cartridges in the read-out instrument. Furthermore, our novel use of a dual surface-energy adhesive film to bond a hard plastic shell directly to the PDMS microfluidic network allows for fast and leak-tight assembly of compact cartridges with tightly spaced fluidic interconnects. The high sensitivity of the slot-waveguide resonators, combined with on-chip referencing and physical modelling, yields a volume refractive index detection limit of 5 x 10(-6) refractive index units (RIUs) and a surface mass density detection limit of 0.9 pg mm(-2), to our knowledge the best reported values for integrated planar ring resonators.

  4. Shear sensing based on a microstrip patch antenna

    NASA Astrophysics Data System (ADS)

    Mohammad, I.; Huang, H.

    2012-10-01

    A microstrip patch antenna sensor was studied for shear sensing with a targeted application of measuring plantar shear distribution on a diabetic foot. The antenna shear sensor consists of three components, namely an antenna patch, a soft foam substrate and a slotted ground plane. The resonant frequency of the antenna sensor is sensitive to the overlapping length between the slot in the ground plane and the antenna patch. A shear force applied along the direction of the slot deforms the foam substrate and causes a change in the overlapping length, which can be detected from the antenna frequency shift. The antenna shear sensor was designed based on simulated antenna frequency response and validated by experiments. Experimental results indicated that the antenna sensor exhibits high sensitivity to shear deformation and responds to the applied shear loads with excellent linearity and repeatability.

  5. Angular Displacement and Velocity Sensors Based on Coplanar Waveguides (CPWs) Loaded with S-Shaped Split Ring Resonators (S-SRR)

    PubMed Central

    Naqui, Jordi; Coromina, Jan; Karami-Horestani, Ali; Fumeaux, Christophe; Martín, Ferran

    2015-01-01

    In this paper, angular displacement and angular velocity sensors based on coplanar waveguide (CPW) transmission lines and S-shaped split ring resonators (S-SRRs) are presented. The sensor consists of two parts, namely a CPW and an S-SRR, both lying on parallel planes. By this means, line-to-resonator magnetic coupling arises, the coupling level being dependent on the line-to-resonator relative angular orientation. The line-to-resonator coupling level is the key parameter responsible for modulating the amplitude of the frequency response seen between the CPW ports in the vicinity of the S-SRR fundamental resonance frequency. Specifically, an amplitude notch that can be visualized in the transmission coefficient is changed by the coupling strength, and it is characterized as the sensing variable. Thus, the relative angular orientation between the two parts is measured, when the S-SRR is attached to a rotating object. It follows that the rotation angle and speed can be inferred either by measuring the frequency response of the S-SRR-loaded line, or the response amplitude at a fixed frequency in the vicinity of resonance. It is in addition shown that the angular velocity can be accurately determined from the time-domain response of a carrier time-harmonic signal tuned at the S-SRR resonance frequency. The main advantage of the proposed device is its small size directly related to the small electrical size of the S-SRR, which allows for the design of compact angular displacement and velocity sensors at low frequencies. Despite the small size of the fabricated proof-of-concept prototype (electrically small structures do not usually reject signals efficiently), it exhibits good linearity (on a logarithmic scale), sensitivity and dynamic range. PMID:25915590

  6. Angular Displacement and Velocity Sensors Based on Coplanar Waveguides (CPWs) Loaded with S-Shaped Split Ring Resonators (S-SRR).

    PubMed

    Naqui, Jordi; Coromina, Jan; Karami-Horestani, Ali; Fumeaux, Christophe; Martín, Ferran

    2015-04-23

    In this paper, angular displacement and angular velocity sensors based on coplanar waveguide (CPW) transmission lines and S-shaped split ring resonators (S-SRRs) are presented. The sensor consists of two parts, namely a CPW and an S-SRR, both lying on parallel planes. By this means, line-to-resonator magnetic coupling arises, the coupling level being dependent on the line-to-resonator relative angular orientation. The line-to-resonator coupling level is the key parameter responsible for modulating the amplitude of the frequency response seen between the CPW ports in the vicinity of the S-SRR fundamental resonance frequency. Specifically, an amplitude notch that can be visualized in the transmission coefficient is changed by the coupling strength, and it is characterized as the sensing variable. Thus, the relative angular orientation between the two parts is measured, when the S-SRR is attached to a rotating object. It follows that the rotation angle and speed can be inferred either by measuring the frequency response of the S-SRR-loaded line, or the response amplitude at a fixed frequency in the vicinity of resonance. It is in addition shown that the angular velocity can be accurately determined from the time-domain response of a carrier time-harmonic signal tuned at the S-SRR resonance frequency. The main advantage of the proposed device is its small size directly related to the small electrical size of the S-SRR, which allows for the design of compact angular displacement and velocity sensors at low frequencies. Despite the small size of the fabricated proof-of-concept prototype (electrically small structures do not usually reject signals efficiently), it exhibits good linearity (on a logarithmic scale), sensitivity and dynamic range.

  7. Parameter optimization analysis to minimize the polarization error in a localized thermal tunable fiber ring resonator gyro.

    PubMed

    Bobbili, Prasada Rao; Nayak, Jagannath; Pinnoji, Prerana Dabral; Rama Koti Reddy, D V

    2016-03-10

    The accuracy of the resonant frequency servo loop is a major concern for the high-performance operation of a resonant fiber optic gyro. For instance, a bias error as large as tens or even hundreds of degrees/hour has been observed at the demodulated output of the resonant frequency servo loop. The traditional frequency servo mechanism is not an efficient tool to address this problem. In our previous work, we proposed a novel method to minimize the laser frequency noise to the level of the shot noise by refractive index modulation by a thermally tunable resonator. In this paper, we performed the parameter optimization for the resonator coil, multifunction integrated-optics chip, and couplers by the transition matrix using the Jones matrix methodology to minimize the polarization error. With the optimized parameter values, we achieved the bias value of the resonator fiber optic gyro to 1.924°/h.

  8. Spin Polarization of Carriers in InGaAs Self-Assembled Quantum Rings Inserted in GaAs-AlGaAs Resonant Tunneling Devices

    NASA Astrophysics Data System (ADS)

    Orsi Gordo, V.; Gobato, Y. Galvão; Galeti, H. V. A.; Brasil, M. J. S. P.; Taylor, D.; Henini, M.

    2017-03-01

    In this work, we have investigated transport and polarization resolved photoluminescence (PL) of n-type GaAs-AlGaAs resonant tunneling diodes (RTDs) containing a layer of InGaAs self-assembled quantum rings (QRs) in the quantum well (QW). All measurements were performed under applied voltage, magnetic fields up to 15 T and using linearly polarized laser excitation. It was observed that the QRs' PL intensity and the circular polarization degree (CPD) oscillate periodically with applied voltage under high magnetic fields at 2 K. Our results demonstrate an effective voltage control of the optical and spin properties of InGaAs QRs inserted into RTDs.

  9. High-energy, sub-100 fs, all-fiber stretched-pulse mode-locked Er-doped ring laser with a highly-nonlinear resonator.

    PubMed

    Dvoretskiy, Dmitriy A; Lazarev, Vladimir A; Voropaev, Vasiliy S; Rodnova, Zhanna N; Sazonkin, Stanislav G; Leonov, Stanislav O; Pnev, Alexey B; Karasik, Valeriy E; Krylov, Alexander A

    2015-12-28

    We report on ultra-short stretched pulse generation in an all-fiber erbium-doped ring laser with a highly-nonlinear germanosilicate fiber inside the resonator with a slightly positive net-cavity group velocity dispersion (GVD). Stable 84 fs pulses were obtained with a 12 MHz repetition rate at a central wavelength of 1560 nm with a 48.1 nm spectral pulse width (full width at half maximum, FWHM) and 30 mW average output power; this corresponds to the 29.7 kW maximum peak power and 2.5 nJ pulse energy obtained immediately from the oscillator.

  10. Slotline fed microstrip antenna array modules

    NASA Technical Reports Server (NTRS)

    Lo, Y. T.; Oberhart, M. L.; Brenneman, J. S.; Aoyagi, P.; Moore, J.; Lee, R. Q. H.

    1988-01-01

    A feed network comprised of a combination of coplanar waveguide and slot transmission line is described for use in an array module of four microstrip elements. Examples of the module incorporating such networks are presented as well as experimentally obtained impedance and radiation characteristics.

  11. Rectangular microstrip antenna on a ferrite substrate

    NASA Astrophysics Data System (ADS)

    Das, S.; Chowdhury, S. K.

    1982-05-01

    The bandwidth and radiation characteristics of a simple quarter wave microstrip antenna on a typical ferrite substrate are measured and compared with the theoretical results in the lower range of ultrahigh frequency (UHF). A method has also been discussed for impedance matching of the antenna to the feed line.

  12. Microstrip antenna arrays with parasitic elements

    NASA Technical Reports Server (NTRS)

    Lee, Kai-Fong

    1996-01-01

    This research was concerned with using parasitic elements to improve the bandwidth, gain and axial ratio characteristics of microstrip antennas and arrays. Significant improvements in these characteristics were obtained using stacked and coplanar parasitic elements. Details of the results are described in a total of 16 journal and 17 conference papers. These are listed in Section four of this report.

  13. Coplanar waveguide feed for microstrip patch antennas

    NASA Technical Reports Server (NTRS)

    Smith, R. L.; Williams, J. T.

    1992-01-01

    A coplanar waveguide (CPW) loop is shown to be an effective low VSWR feed for microstrip antennas. The low VSWR transition between the CPW and the antenna is obtained without the use of a matching circuit, and it is relatively insensitive to the position of the antenna and the feed.

  14. Deployable Fresnel Rings

    NASA Technical Reports Server (NTRS)

    Kennedy, Timothy F.; Fink, Patrick W.; Chu, Andrew W.; Lin, Gregory Y.

    2014-01-01

    Deployable Fresnel rings (DFRs) significantly enhance the realizable gain of an antenna. This innovation is intended to be used in combination with another antenna element, as the DFR itself acts as a focusing or microwave lens element for a primary antenna. This method is completely passive, and is also completely wireless in that it requires neither a cable, nor a connector from the antenna port of the primary antenna to the DFR. The technology improves upon the previous NASA technology called a Tri-Sector Deployable Array Antenna in at least three critical aspects. In contrast to the previous technology, this innovation requires no connector, cable, or other physical interface to the primary communication radio or sensor device. The achievable improvement in terms of antenna gain is significantly higher than has been achieved with the previous technology. Also, where previous embodiments of the Tri-Sector antenna have been constructed with combinations of conventional (e.g., printed circuit board) and conductive fabric materials, this innovation is realized using only conductive and non-conductive fabric (i.e., "e-textile") materials, with the possible exception of a spring-like deployment ring. Conceptually, a DFR operates by canceling the out-of-phase radiation at a plane by insertion of a conducting ring or rings of a specific size and distance from the source antenna, defined by Fresnel zones. Design of DFRs follow similar procedures to those outlined for conventional Fresnel zone rings. Gain enhancement using a single ring is verified experimentally and through computational simulation. The experimental test setup involves a microstrip patch antenna that is directly behind a single-ring DFR and is radiating towards a second microstrip patch antenna. The first patch antenna and DFR are shown. At 2.42 GHz, the DFR improves the transmit antenna gain by 8.6 dB, as shown in Figure 2, relative to the wireless link without the DFR. A figure illustrates the

  15. Electromagnetic wave energy flow control with a tunable and reconfigurable coupled plasma split-ring resonator metamaterial: A study of basic conditions and configurations

    NASA Astrophysics Data System (ADS)

    Kourtzanidis, Konstantinos; Pederson, Dylan M.; Raja, Laxminarayan L.

    2016-05-01

    We propose and study numerically a tunable and reconfigurable metamaterial based on coupled split-ring resonators (SRRs) and plasma discharges. The metamaterial couples the magnetic-electric response of the SRR structure with the electric response of a controllable plasma slab discharge that occupies a volume of the metamaterial. Because the electric response of a plasma depends on its constitutive parameters (electron density and collision frequency), the plasma-based metamaterial is tunable and active. Using three-dimensional numerical simulations, we analyze the coupled plasma-SRR metamaterial in terms of transmittance, performing parametric studies on the effects of electron density, collisional frequency, and the position of the plasma slab with respect to the SRR array. We find that the resonance frequency can be controlled by the plasma position or the plasma-to-collision frequency ratio, while transmittance is highly dependent on the latter.

  16. Multi-channel microstrip transceiver arrays using harmonics for high field MR imaging in humans.

    PubMed

    Wu, Bing; Wang, Chunsheng; Lu, Jonathan; Pang, Yong; Nelson, Sarah J; Vigneron, Daniel B; Zhang, Xiaoliang

    2012-02-01

    Radio-frequency (RF) transceiver array design using primary and higher order harmonics for in vivo parallel magnetic resonance imaging imaging (MRI) and spectroscopic imaging is proposed. The improved electromagnetic decoupling performance, unique magnetic field distributions and high-frequency operation capabilities of higher-order harmonics of resonators would benefit transceiver arrays for parallel MRI, especially for ultrahigh field parallel MRI. To demonstrate this technique, microstrip transceiver arrays using first and second harmonic resonators were developed for human head parallel imaging at 7T. Phantom and human head images were acquired and evaluated using the GRAPPA reconstruction algorithm. The higher-order harmonic transceiver array design technique was also assessed numerically using FDTD simulation. Compared with regular primary-resonance transceiver designs, the proposed higher-order harmonic technique provided an improved g-factor and increased decoupling among resonant elements without using dedicated decoupling circuits, which would potentially lead to a better parallel imaging performance and ultimately faster and higher quality imaging. The proposed technique is particularly suitable for densely spaced transceiver array design where the increased mutual inductance among the elements becomes problematic. In addition, it also provides a simple approach to readily upgrade the channels of a conventional primary resonator microstrip array to a larger number for faster imaging.

  17. Effect of Weaving Direction of Conductive Yarns on Electromagnetic Performance of 3D Integrated Microstrip Antenna

    NASA Astrophysics Data System (ADS)

    Xu, Fujun; Yao, Lan; Zhao, Da; Jiang, Muwen; Qiu, Yipping

    2013-10-01

    A three-dimensionally integrated microstrip antenna (3DIMA) is a microstrip antenna woven into the three-dimensional woven composite for load bearing while functioning as an antenna. In this study, the effect of weaving direction of conductive yarns on electromagnetic performance of 3DIMAs are investigated by designing, simulating and experimental testing of two microstrip antennas with different weaving directions of conductive yarns: one has the conductive yarns along the antenna feeding direction (3DIMA-Exp1) and the other has the conductive yarns perpendicular the antenna feeding direction (3DIMA-Exp2). The measured voltage standing wave ratio (VSWR) of 3DIMA-Exp1 was 1.4 at the resonant frequencies of 1.39 GHz; while that of 3DIMA-Exp2 was 1.2 at the resonant frequencies of 1.35 GHz. In addition, the measured radiation pattern of the 3DIMA-Exp1 has smaller back lobe and higher gain value than those of the 3DIMA-Exp2. This result indicates that the waving direction of conductive yarns may have a significant impact on electromagnetic performance of textile structural antennas.

  18. Tunable Microstrip Filters Using Selectively Etched Ferroelectric Thin-Film Varactors for Coupling

    NASA Technical Reports Server (NTRS)

    Mueller, Carl H.; VanKeuls, Frederick W.; Romanofsky, Robert R.; Subramanyam, Guru; Miranda, Felix A.

    2006-01-01

    We report on the use of patterned ferroelectric films to fabricate proof of concept tunable one-pole microstrip filters with excellent transmission and mismatch/reflection properties at frequencies up to 24 GHz. By controlling the electric field distribution within the coupling region between the resonator and input/output lines, sufficiently high loaded and unloaded Q values are maintained so as to be useful for microstrip filter design, with low mismatch loss. In the 23 - 24 GHz region, the filter was tunable over a 100 MHz range, the loaded and unloaded Q values were 29 and 68, respectively, and the reflection losses were below -16 dB, which demonstrates the suitability of these films for practical microwave applications.

  19. GaInAsP/silicon-on-insulator hybrid laser with ring-resonator-type reflector fabricated by N2 plasma-activated bonding

    NASA Astrophysics Data System (ADS)

    Hayashi, Yusuke; Suzuki, Junichi; Inoue, Satoshi; Tanvir Hasan, Shovon Muhammad; Kuno, Yuki; Itoh, Kazuto; Amemiya, Tomohiro; Nishiyama, Nobuhiko; Arai, Shigehisa

    2016-08-01

    III-V/Si hybrid integration with direct bonding is an attractive method of realizing an electrophotonic convergence router with a small size and a low power consumption. Plasma-activated bonding (PAB) is an effective approach for reducing thermal stress during the bonding process because PAB achieves a high bonding strength with low-temperature annealing. This time, the fabrication of a GaInAsP/silicon-on-insulator (SOI) hybrid laser with Si ring-resonator-type reflectors was demonstrated by N2 PAB. By measuring the lasing spectra, we confirmed the reflective characteristics resulting from the cascaded Si ring resonators. We also investigated kink characteristics, which occur around the threshold current, of the current-light output (I-L) characteristics, and successfully approximated the kink characteristics by considering saturable absorption occurring at the III-V/Si taper tip. The taper structure was investigated in terms of a passive device as well as an active device, and a structure for eliminating saturable absorption was proposed.

  20. One-port ring refractive index sensor with attached sub-ring

    NASA Astrophysics Data System (ADS)

    Okayama, H.; Takahisa, H.; Tsutsui, M.; Mendez-Astudillo, M.; Nakajima, H.

    2017-02-01

    In this report, we propose a ring resonator with one port for surface normal input/output attached with another ring resonator. A resonance generated by one of the ring resonators is used for sensing and that by the other as a reference. The device characteristics were examined using the FDTD simulation.

  1. Directive properties analysis of the circular microstrip antenna

    NASA Astrophysics Data System (ADS)

    Katulski, Ryszard J.

    The effect of mode type on the directive properties of a circular microstrip antenna are investigated by means of numerical modeling in which a cavity model of the antenna is used. The structure and the cavity model principles are described. Numerical investigations of the directive properties of a single microstrip antenna element and the microstrip antenna array for dominant and higher modes of the antenna excitation are presented. Radiation pattern shapes of the circular microstrip antenna and the antenna array indicate that the antenna tends to receive the undesirable signals.

  2. Flexible Microstrip Circuits for Superconducting Electronics

    NASA Technical Reports Server (NTRS)

    Chervenak, James; Mateo, Jennette

    2013-01-01

    Flexible circuits with superconducting wiring atop polyimide thin films are being studied to connect large numbers of wires between stages in cryogenic apparatus with low heat load. The feasibility of a full microstrip process, consisting of two layers of superconducting material separated by a thin dielectric layer on 5 mil (approximately 0.13 mm) Kapton sheets, where manageable residual stress remains in the polyimide film after processing, has been demonstrated. The goal is a 2-mil (approximately 0.051-mm) process using spin-on polyimide to take advantage of the smoother polyimide surface for achieving highquality metal films. Integration of microstrip wiring with this polyimide film may require high-temperature bakes to relax the stress in the polyimide film between metallization steps.

  3. Input impedance of arbitrarily shaped microstrip antennas

    NASA Astrophysics Data System (ADS)

    Pichon, P.; Mosig, J.; Papiernik, A.

    1988-09-01

    The paper deals with the analysis of arbitrarily shaped microstrip antennas. A powerful and flexible technique is obtained by combining a mixed potential integral equation, successfully used for rectangular patches, with a method of moments, using a division of the patch into triangular cells and overlapping basis functions, defined over cell couples. The resulting computer algorithm is validated by comparing its predictions with the measurements obtained from an equilateral triangular patch.

  4. Influence of Ring-Expanded N-Heterocyclic Carbenes on the Structures of Half-Sandwich Ni(I) Complexes: An X-ray, Electron Paramagnetic Resonance (EPR), and Electron Nuclear Double Resonance (ENDOR) Study.

    PubMed

    Pelties, Stefan; Carter, Emma; Folli, Andrea; Mahon, Mary F; Murphy, Damien M; Whittlesey, Michael K; Wolf, Robert

    2016-11-07

    Potassium graphite reduction of the half-sandwich Ni(II) ring-expanded diamino/diamidocarbene complexes CpNi(RE-NHC)Br gave the Ni(I) derivatives CpNi(RE-NHC) (where RE-NHC = 6-Mes (1), 7-Mes (2), 6-MesDAC (3)) in yields of 40%-50%. The electronic structures of paramagnetic 1-3 were investigated by CW X-/Q-band electron paramagnetic resonance (EPR) and Q-band (1)H electron nuclear double resonance (ENDOR) spectroscopy. While small variations in the g-values were observed between the diaminocarbene complexes 1 and 2, pronounced changes in the g-values were detected between the almost isostructural species (1) and diamidocarbene species (3). These results highlight the sensitivity of the EPR g-tensor to changes in the electronic structure of the Ni(I) centers generated by incorporation of heteroatom substituents onto the backbone ring positions. Variable-temperature EPR analysis also revealed the presence of a second Ni(I) site in 3. The experimental g-values for these two Ni(I) sites detected by EPR in frozen solutions of 3 are consistent with resolution on the EPR time scale of the disordered components evident in the X-ray crystallographically determined structure and the corresponding density functional theory (DFT)-calculated g-tensor. Q-band (1)H ENDOR measurements revealed a small amount of unpaired electron spin density on the Cp rings, consistent with the calculated SOMO of complexes 1-3. The magnitude of the (1)H A values for 3 were also notably larger, compared to 1 and 2, again highlighting the influence of the diamidocarbene on the electronic properties of 3.

  5. Electric and magnetic properties computed for valence bond structures: is there a link between pauling resonance energy and ring current?

    PubMed

    Havenith, Remco W A

    2006-04-28

    To establish the link between the aromaticity descriptors based on the Pauling resonance energy and the molecular properties, the electric (polarizability) and magnetic (magnetizability) field response properties have been calculated using the valence bond approach for various molecules and their individual Kekulé resonance structures. The results show that there is no direct relationship between the Pauling resonance energy and the properties; the response properties are weighted averages of the properties of the individual structures. According to the aromaticity criteria based on molecular properties, one-structure benzene would be aromatic; thus, concerning molecular properties, spin-coupled bonds do not behave like localized bonds in Lewis structures, with which they are usually associated.

  6. Microstrip transmission line tapers on ferrites

    SciTech Connect

    Albuquerque, M.R.; dAssuncao, A.G.; Lima, F.

    1997-04-01

    The spectral domain approach is employed to perform a theoretical investigation of tapered microstrip lines on magnetized ferrite substrates. A linear variation of the conducting strip width along the direction of propagation is considered. The analysis takes into account the effects of the applied dc magnetic bias field in the transmission characteristics of these structures. The properties of the taper are determined by a model based on a segmentation of the considered line into uniform microstrip line subsections. Normalized phase constants and characteristic impedances are obtained by using the Hertz vector potentials method and Galerkin numerical technique. Numerical results are presented to show the taper input parameters as a function of the load impedance, geometrical dimensions, operating frequency, and ferrite parameters, considering the orientation and magnitude changes of the biasing magnetic-field {bold H}{sub 0}. The results agree fairly well with those available in the literature for tapered microstrip lines on isotropic dielectric substrates. {copyright} {ital 1997 American Institute of Physics.}

  7. Rectangular Microstrip Antenna with Slot Embedded Geometry

    NASA Astrophysics Data System (ADS)

    Ambresh, P. A.; Hadalgi, P. M.; Hunagund, P. V.; Sujata, A. A.

    2014-09-01

    In this paper, a novel design that improves the performance of conventional rectangular microstrip antenna is discussed. Design adopts basic techniques such as probe feeding technique with rectangular inverted patch structure as superstrate, air filled dielectric medium as substrate and slot embedded patch. Prototype of the proposed antenna has been fabricated and various antenna performance parameters such as impedance bandwidth, return loss, radiation pattern and antenna gain are considered for Electromagnetic-study. The antennas are designed for the wireless application operating in the frequency range of 3.3 GHz to 3.6 GHz, and UK based fixed satellite service application (3 GHz to 4 GHz), and are named as single inverted patch conventional rectangular microstrip antenna (SIP-CRMSA) and slots embedded inverted patch rectangular microstrip antenna (SEIP-RMSA), respectively. Measurement outcomes for SEIP-RMSA1 and SEIP-RMSA2 showed the satisfactory performance with an achievable impedance bandwidth of 260 MHz (7 %) and 250 MHz (6.72 %), with return loss (RL) of -11.06 dB and -17.98 dB, achieved gain of 8.17 dB and 5.17 dB with 10% and 8% size reduction in comparison with the conventional patch antenna.

  8. Picosecond optically reconfigurable filters exploiting full free spectral range tuning of single ring and Vernier effect resonators.

    PubMed

    Bruck, Roman; Mills, Ben; Thomson, David J; Troia, Benedetto; Passaro, Vittorio M N; Mashanovich, Goran Z; Reed, Graham T; Muskens, Otto L

    2015-05-04

    We demonstrate that phase shifts larger than 2π can be induced by all-optical tuning in silicon waveguides of a few micrometers in length. By generating high concentrations of free carriers in the silicon employing absorption of ultrashort, ultraviolet laser pulses, the refractive index of silicon can be drastically reduced. As a result, the resonance wavelength of optical resonators can be freely tuned over the full free spectral range. This allows for active integrated optic devices that can be switched with GHz frequencies into any desired state by all-optical means.

  9. Planar FET oscillators using periodic microstrip patch antennas

    NASA Astrophysics Data System (ADS)

    Birkeland, Joel; Itoh, Tatsuo

    1989-08-01

    An integrated oscillator/antenna is presented that uses a single microstrip leaky-wave structure as both the resonant and the radiating element. This resonant antenna is connected to a GaAs metal-semiconductor field-effect transistor which acts as the negative resistance element in the oscillator circuit. This type of oscillator is similar in its operating principle to one reported using Gunn diodes and a periodically notched dielectric image guide. This circuit exhibits the high DC-RF conversion efficiency that is typical of field-effect transistor oscillators. The planar circuit is simple and inexpensive to construct, occupies a small volume, and can conform to different surface profiles. Such circuits are suitable for use in millimeter-wave systems as well as at microwave frequencies. A design procedure is given, and the performance of X-band prototype circuits is reported. Prototype circuits showed a 9 dB isotropic conversion gain and 40 MHz tuning range at 9.5 GHz.

  10. A parallel-series-fed microstrip array with high efficiency and low cross-polarization

    NASA Technical Reports Server (NTRS)

    Huang, John

    1992-01-01

    The requirements of a microstrip array with a vertically polarized fan beam are addressed that correspond to its use in C-band interferometric SAR. A combination of parallel- and series-feed techniques are utilized in an array design with a three-stage parallel-fed configuration to enhance bandwidth performance. The linearly polarized traveling-wave microstrip array antenna is fed by microstrip transmission lines in two rows of 36 elements that resonate at 5.30 GHz. The transmission lines are impedance-matched at every junction for all the waves that travel toward the two ends of the array. The two measured principal-plane patterns are shown, and the measured narrow-beam pattern is found to agree with the calculated values. The VSWR bandwidths and narrow and broad beamwidths of the antenna are found to permit efficient performance. The efficiency is attributed to the parallel and series-feed configuration which allows proper impedance matching, and low cross-polarization is a result of the antiphase feed technique employed in the configuration.

  11. Tunable microstrip SQUID amplifiers for the Gen 2 Axion Dark Matter eXperiment (ADMX)

    NASA Astrophysics Data System (ADS)

    O'Kelley, Sean; Hilton, Gene; Clarke, John

    We present a series of tunable microstrip SQUID amplifiers (MSAs) for installation in ADMX. The axion dark matter candidate is detected via Primakoff conversion to a microwave photon in a high-Q (~100,000) tunable microwave cavity cooled with a dilution refrigerator in the presence of a 7-tesla magnetic field. The microwave photon frequency ν is a function of the unknown axion mass, so both the cavity and amplifier must be scanned over a wide frequency range. An MSA is a linear, phase-preserving amplifier consisting of a superconducting, resonant microstrip flux-coupled to a resistively-shunted dc SQUID biased into the voltage state. Tunability is achieved by terminating the microstrip with low inductance GaAs varactor diodes that operate below 100 mK. By varying the bias voltage of the varactors we vary their capacitance, allowing a reflected phase varying from nearly 0 to π, thus achieving a tunability close to a factor of 2. We demonstrate several devices operating below 100 mK, matched to the discrete operating bands of ADMX at frequencies ranging from 560 MHz to 1 GHz, that exhibit gains exceeding 20 dB. The associated noise temperatures, measured with a hot/cold load, approach the standard quantum limit (hν/kB) for a linear phase-preserving amplifier.

  12. Closed Form Formulas for Distributed Circuit Model of Discontinuities in HTS Microstrip Transmission Lines

    NASA Astrophysics Data System (ADS)

    Javadzadeh, S. Mohammad Hassan; Mamaghany, Zahra Mardy; Farzaneh, Forouhar; Fardmanesh, Mehdi

    A distributed circuit model for different kinds of discontinuities in high temperature superconducting (HTS) microstrip transmission lines (TLs), is proposed. In each case, closed form formula for lumped element model is presented based on the configuration of the discontinuity and the characterizations of HTS microstrip TLs. These discontinuities consist of steps in width, open ends, gaps and 90-degree bends. In the case of normal conductor microstrip TLs there are a lot of numerical and analytical equations that can accurately model them, however those formulas are not efficient for HTS TLs. Thus modified relations are extracted utilizing the superconducting characterizations to obtain much more accurate formulas. Additionally temperature dependence of HTS TLs is considered in the relations. Moreover regarding the kinetic inductance in HTS TLs a closed form formula is proposed for characteristic impedance of HTS TLs. Furthermore correction factors based on fringe fields is used to optimize all formulas. Using these formulations can lead to modeling and analysis of some superconducting microwave devices such as resonators, microwave filters, couplers, etc. In contrast to EM analysis, using the distributed circuit model is much easier for analysis of HTS microwave devices. The accuracy of the proposed model is confirmed in comparison with some electromagnetic full-wave simulations. This full analytical approach shows great accuracy in this test case as well.

  13. Single-frequency, injection-seeded Er:YAG laser based on a bow-tie ring slave resonator

    NASA Astrophysics Data System (ADS)

    Yao, B. Q.; Deng, Yu; Dai, T. Y.; Duan, X. M.; You-Lun, Ju; Wang, Y. Z.

    2015-08-01

    A diode pumped, injection-seeded Q-switched Er:YAG laser at 1645.2 nm is demonstrated. A single frequency Er:YAG monolithic nonplanar ring oscillator (NPRO) laser emitting at 1645.24 nm with a maximum output power of 500 mW is used as a seed laser. The seed laser output is injected into a bow-tie slave laser, obtaining stable single-frequency Q-switched operation of the Er:YAG laser. The maximum single-frequency Q-switched Er:YAG laser output energy is 2.9 mJ at 100 Hz with a pulse duration of 160 ns.

  14. Generation of surface-wave microwave microplasmas in hollow-core photonic crystal fiber based on a split-ring resonator.

    PubMed

    Vial, Florian; Gadonna, Katell; Debord, Benoît; Delahaye, Frédéric; Amrani, Foued; Leroy, Olivier; Gérôme, Frédéric; Benabid, Fetah

    2016-05-15

    We report on a new and highly compact scheme for the generation and sustainment of microwave-driven plasmas inside the core of an inhibited coupling Kagome hollow-core photonic crystal fiber. The microwave plasma generator consists of a split-ring resonator that efficiently couples the microwave field into the gas-filled fiber. This coupling induces the concomitant generation of a microwave surface wave at the fiber core surround and a stable plasma column confined in the fiber core. The scheme allowed the generation of several centimeters long argon microplasma columns with a very low excitation power threshold. This result represents an important step toward highly compact plasma lasers or plasma-based photonic components.

  15. Resonantly pumped monolithic nonplanar Ho:YAG ring laser with high-power single-frequency laser output at 2122 nm.

    PubMed

    Wang, Lei; Gao, Chunqing; Gao, Mingwei; Li, Yan

    2013-04-22

    We demonstrated a stable single-frequency laser operating at 2122 nm from a monolithic nonplanar Ho:YAG ring oscillator (NPRO). The Ho:YAG NPRO was resonantly pumped by a 1907 nm Tm:YLF laser built up by ourselves. The maximum multimode output power from the Ho:YAG NPRO was 9.66 W and the slope efficiency was 71.7%. With accurate adjustment of the pump position to make the laser oscillate in single frequency condition, an output power of 8.0 W was obtained with a slope efficiency of 61.4% and an optical-optical efficiency of 50.0%. The power stability of the Ho:YAG NPRO laser was 0.29% at maximum single frequency output power. The beam quality M(2) factors were measured to be less than 1.1 in x- and y- directions.

  16. A wavelength tunable ONU transmitter based on multi-mode Fabry-Perot laser and micro-ring resonator for bandwidth symmetric TWDM-PON

    NASA Astrophysics Data System (ADS)

    Gao, Zhensen; Sun, Xiao; Zhang, Kaibin

    2016-02-01

    Wavelength tunable optical transmitter is an essential component for the newly standardized time and wavelength division multiplexed passive optical network (TWDM-PON), where tunable ONU with 10Gb/s bit rate is desired to provide 40Gb/s symmetric bandwidth. In this paper, a novel wavelength tunable optical transmitter is proposed by reusing legacy low speed multi-mode Fabry-Perot laser and connecting it with an integrated photonic chip with two coupled micro-ring resonators to generate a tunable single mode signal based on Vernier effect for 10Gb/s high speed modulation, which makes it as a promising solution for colorless ONU in future symmetric TWDM-PON.

  17. Prospects of high-resolution resonant X-ray inelastic scattering studies on solid materials, liquids and gases at diffraction-limited storage rings

    PubMed Central

    Schmitt, Thorsten; de Groot, Frank M. F.; Rubensson, Jan-Erik

    2014-01-01

    The spectroscopic technique of resonant inelastic X-ray scattering (RIXS) will particularly profit from immensely improved brilliance of diffraction-limited storage rings (DLSRs). In RIXS one measures the intensities of excitations as a function of energy and momentum transfer. DLSRs will allow for pushing the achievable energy resolution, signal intensity and the sampled spot size to new limits. With RIXS one nowadays probes a broad range of electronic systems reaching from simple molecules to complex materials displaying phenomena like peculiar magnetism, two-dimensional electron gases, superconductivity, photovoltaic energy conversion and heterogeneous catalysis. In this article the types of improved RIXS studies that will become possible with X-ray beams from DLSRs are envisioned. PMID:25177995

  18. Optofluidic ring resonator sensor for sensitive label-free detection of breast cancer antigen CA15-3 in human serum

    NASA Astrophysics Data System (ADS)

    Zhu, Hongying; Dale, Paul S.; Fan, Xudong

    2009-05-01

    Breast cancer is the most frequently diagnosed malignancy in women worldwide. Because of its great impact on society, a lot of research funding has been used to develop novel detection tools for aiding breast cancer diagnosis and prognosis. In this work, we demonstrated a simple, fast, and sensitive detection of circulating breast cancer biomarker CA15-3 with opto-fluidic ring resonator (OFRR) sensors. The OFRR sensor employs a thin-walled capillary with wall thickness less than 4 μm. The circular cross section of the capillary forms the optical ring resonator, in which the light circulates in the form of whispering gallery modes (WGMs). The capillary wall is thin enough that the evanescent field of the WGM extends into the capillary core and responds to refractive index changes in the capillary core or close to its interior surface. The WGM spectral position will change when the biomolecules bind to the surface, yielding quantitative and kinetic information about the biomolecule interaction. Here, the direct immunoassay method was employed for the detection of CA15-3 antigen without any signal amplification steps. The sensor performance in both PBS buffer and human serum were investigated, respectively. The experimental detection limit was 5 units/mL in PBS buffer and 30 units/mL for CA15-3 spiked in serum, both of which satisfied clinical diagnosis requirements. The potential use of the OFRR as the point-of-care device for breast cancer detection was tested by measuring the CA15-3 level in blood samples collected from stage IV breast cancer patients and the results were compared with standard clinical test.

  19. Rapid tandem-column micro-gas chromatography based on optofluidic ring resonators with multi-point on-column detection.

    PubMed

    Sun, Yuze; Liu, Jing; Howard, Daniel J; Frye-Mason, Greg; Thompson, Aaron K; Ja, Shiou-jyh; Fan, Xudong

    2010-01-01

    We demonstrated a novel tandem-column micro-gas chromatography (microGC) based on optofluidic ring resonator (OFRR). The OFRR is a thin-walled fused silica capillary whose interior surface is coated with a polymeric stationary phase. The circular cross section of the OFRR forms the micro-ring resonator and supports whispering gallery modes (WGMs). Via tapered optical fibers in contact with the OFRR, the WGM can be excited externally at any positions along the OFRR capillary, thus enabling multi-point, on-column, real-time detection of vapor molecules flowing through the OFRR. In the present OFRR-based tandem-column-based microGC implementation, a 180 cm long conventional GC column coated with a nonpolar stationary phase was followed by a relatively short OFRR column coated with a polar phase. Two detection positions, one at the inlet of the OFRR and the other a few centimeters downstream, were used to monitor the separation achieved by the first and the second column, respectively. Owing to the multi-point on-column detection that provides complementary retention time information on each chemical compound, co-eluted analytes can be well separated and identified on at least one detection channel and no modulation is needed at the interface of tandem columns. Separation and detection of twelve analytes with various volatilities and polarities within four minutes were demonstrated. In addition, the chromatograms obtained from three different locations along the OFRR column demonstrated the system's capability of on-column monitoring of the separation process for the target analyte in a vapor mixture. Our results will lead to the development of a rapid, simple, and portable microGC system with significantly improved selectivity and chemical identification capabilities.

  20. Evolution of elastic and thermal properties during TMOS-gel formation determined by ringing bottle acoustic resonance spectroscopy, impulsive stimulated scattering, photopyroelectric spectroscopy and the hot ball method

    NASA Astrophysics Data System (ADS)

    Xu, Xiaodong; Agustin Flores Cuautle, Jose Jesus; Kouyate, Mansour; Bernardus Roozen, Nicolaas; Goossens, Jozefien; Menon, Preethy; Kuriakose Malayil, Maju; Salenbien, Robbe; Nair Rajesh, Ravindran; Glorieux, Christ; Griesmar, Pascal; Martinez, Loïc; Serfaty, Stéphane

    2016-03-01

    The evolution of the elastic and thermal properties of a tetramethylorthosilicate (TMOS)-based gel that exhibits an extraordinary ringing effect when enclosed in a bottle is investigated during the sol-gel transition. The results demonstrate the feasibility of three proposed experimental methods for monitoring of gels during their formation. The shear stiffening evolution during gelation is monitored by ringing bottle, resonant acoustic spectroscopy and by an ultrasonic technique using piezo electric excitation and detection. The evolution of the longitudinal modulus and the thermal diffusivity of the gel during stiffening are simultaneously determined by a combined photoacoustic and photothermal method based on heterodyne diffraction detection of impulsive stimulated scattering by, respectively, a propagating acoustic wave grating and a decaying thermal expansion grating that were both thermo elastically generated using a pulsed laser. Also, the feasibility of an inverse photopyroelectric method and a hot ball technique to monitor the thermal transport efficiency and thermal impedance of a forming gel by tracking the thermal conductivity, the thermal diffusivity, and the thermal effusivity is demonstrated. The network polymerization and stiffening during the sol-gel transition in TMOS-gel corresponds with substantial changes in the shear acoustic velocity and in all thermal properties, while the longitudinal acoustic velocity is only weakly affected.