Sample records for waveguide heterostructure resonator

  1. Resonant Photonic States in Coupled Heterostructure Photonic Crystal Waveguides

    Directory of Open Access Journals (Sweden)

    Sabarinathan J


    Full Text Available Abstract In this paper, we study the photonic resonance states and transmission spectra of coupled waveguides made from heterostructure photonic crystals. We consider photonic crystal waveguides made from three photonic crystals A, B and C, where the waveguide heterostructure is denoted as B/A/C/A/B. Due to the band structure engineering, light is confined within crystal A, which thus act as waveguides. Here, photonic crystal C is taken as a nonlinear photonic crystal, which has a band gap that may be modified by applying a pump laser. We have found that the number of bound states within the waveguides depends on the width and well depth of photonic crystal A. It has also been found that when both waveguides are far away from each other, the energies of bound photons in each of the waveguides are degenerate. However, when they are brought close to each other, the degeneracy of the bound states is removed due to the coupling between them, which causes these states to split into pairs. We have also investigated the effect of the pump field on photonic crystal C. We have shown that by applying a pump field, the system may be switched between a double waveguide to a single waveguide, which effectively turns on or off the coupling between degenerate states. This reveals interesting results that can be applied to develop new types of nanophotonic devices such as nano-switches and nano-transistors.

  2. Folded waveguide resonator

    DEFF Research Database (Denmark)


    A waveguide resonator comprising a number of side walls defining a cavity enclosed by said sidewalls defining the cavity; and two or more conductive plates extending into the cavity, each conductive plate having a first side and a second side opposite the first side, and wherein the conductive...... plates are adapted to cause a standing electromagnetic wave to fold around the conductive plates along at least a first and a second direction and to extend on both sides of each of the conductive plates; wherein the conductive plates are adapted to cause the standing electromagnetic wave to fold...

  3. Neutron resonances in planar waveguides

    Energy Technology Data Exchange (ETDEWEB)

    Kozhevnikov, S. V., E-mail:, E-mail:; Ignatovich, V. K.; Petrenko, A. V. [Joint Institute for Nuclear Research, Neutron Physics Laboratory (Russian Federation); Radu, F. [Helmholtz-Zentrum Berlin für Materialen und Energie (Germany)


    We report on the results of the experimental investigation of the spectral width of neutron resonances in planar waveguides using the time-of-flight method and recording the microbeam emerging from the waveguide end. Experimental data are compared with the results of theoretical calculations.

  4. Paired modes of heterostructure cavities in photonic crystal waveguides with split band edges

    DEFF Research Database (Denmark)

    Mahmoodian, Sahand; Sukhorukov, Andrey A.; Ha, Sangwoo


    We investigate the modes of double heterostructure cavities where the underlying photonic crystal waveguide has been dispersion engineered to have two band-edges inside the Brillouin zone. By deriving and using a perturbative method, we show that these structures possess two modes. For unapodized...... cavities, the relative detuning of the two modes can be controlled by changing the cavity length, and for particular lengths, a resonant-like effect makes the modes degenerate. For apodized cavities no such resonances exist and the modes are always non-degenerate....

  5. Waveguide couplers for ferroelectric optical resonators


    Grudinin, Ivan S.; Kozhanov, A.; Yu, N.


    We report a study of using the same material to fabricate a whispering gallery mode resonator and a coupler. Coupling to high Q whispering gallery modes of the lithium niobate resonator is demonstrated by means of the titanium-doped waveguide. The waveguide coupling approach opens possibilities for simpler and wider practical usage of whispering gallery mode resonators and their integration into optical devices.

  6. Single and Double Superconducting Coplanar Waveguide Resonators (United States)

    Zhao, Na; Liu, Jian-She; Li, Hao; Li, Tie-Fu; Chen, Wei


    Transmission characteristics of single and double coplanar waveguide (CPW) resonators are simulated. The crosstalk of two CPW resonators located on the same chip is observed in simulation as well as in low temperature measurement results. The crosstalk behaves as exponential attenuation versus the distance between two resonators.

  7. Control of resonances in photonic crystal waveguides

    NARCIS (Netherlands)

    Lian, Jin


    Photonic crystal waveguides (PhCWG) with intentional defects and unavoidable disorder exhibit high quality factor (Q) resonances. Single- and multi-resonance systems based on them are suitable for applications such as optical memories, delay lines and cavity QED. Therefore, characterization, control

  8. Compact on-Chip Temperature Sensors Based on Dielectric-Loaded Plasmonic Waveguide-Ring Resonators

    Directory of Open Access Journals (Sweden)

    Sergey I. Bozhevolnyi


    Full Text Available The application of a waveguide-ring resonator based on dielectric-loaded surface plasmon-polariton waveguides as a temperature sensor is demonstrated in this paper and the influence of temperature change to the transmission through the waveguide-ring resonator system is comprehensively analyzed. The results show that the roundtrip phase change in the ring resonator due to the temperature change is the major reason for the transmission variation. The performance of the temperature sensor is also discussed and it is shown that for a waveguide-ring resonator with the resonator radius around 5 mm and waveguide-ring gap of 500 nm which gives a footprint around 140 µm2, the temperature sensitivity at the order of 10−2 K can be achieved with the input power of 100 mW within the measurement sensitivity limit of a practical optical detector.

  9. THz parallel-plate waveguides with resonant cavities

    DEFF Research Database (Denmark)

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


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

  10. Nanoscale constrictions in superconducting coplanar waveguide resonators

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins, Mark David; Naether, Uta; Ciria, Miguel; Zueco, David; Luis, Fernando, E-mail: [Instituto de Ciencia de Materiales de Aragón, CSIC—Universidad de Zaragoza, 50009 Zaragoza (Spain); Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza (Spain); Sesé, Javier [Instituto de Nanociencia de Aragón, Universidad de Zaragoza, E-50009 Zaragoza (Spain); Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza (Spain); Atkinson, James; Barco, Enrique del [Department of Physics, University of Central Florida, Orlando, Florida 32816 (United States); Sánchez-Azqueta, Carlos [Dpto. de Ingeniería Electrónica y Telecomunicaciones, Universidad de Zaragoza, 50009 Zaragoza (Spain); Majer, Johannes [Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna (Austria)


    We report on the design, fabrication, and characterization of superconducting coplanar waveguide resonators with nanoscopic constrictions. By reducing the size of the center line down to 50 nm, the radio frequency currents are concentrated and the magnetic field in its vicinity is increased. The device characteristics are only slightly modified by the constrictions, with changes in resonance frequency lower than 1% and internal quality factors of the same order of magnitude as the original ones. These devices could enable the achievement of higher couplings to small magnetic samples or even to single molecular spins and have applications in circuit quantum electrodynamics, quantum computing, and electron paramagnetic resonance.

  11. Fabrication and Characterization of Superconductive Coplanar Waveguide Resonators : Fabrication and Characterization of Superconductive Coplanar Waveguide Resonators


    Ergül, Adem


    The objective of this thesis is to evaluate a generic process for fabrication and characterization of the Superconductive coplanar waveguide (CPW) resonators. Superconductive CPW resonators with various lengths and shapes are designed to investigate their electrical and magnetic properties as well as resonance properties and sensitivities. In the first part of thesis, two different models are introduced in order to estimate the nonlinear kinetic inductance of a superconducting CPW resonator. ...

  12. Coupled-resonator optical waveguides

    DEFF Research Database (Denmark)

    Raza, Søren; Grgic, Jure; Pedersen, Jesper Goor


    to ideal resonators without any damping. However, the maximal group delay that can be envisioned is a balance between having a low group velocity while not jeopardizing the propagation length. We find that the maximal group delay remains roughly constant over the entire bandwidth, being given by the photon...

  13. Slow Light in Coupled Resonator Optical Waveguides (United States)

    Chang, Hongrok; Gates, Amanda L.; Fuller, Kirk A.; Gregory, Don A.; Witherow, William K.; Paley, Mark S.; Frazier, Donald O.; Smith, David D.; Curreri, Peter A. (Technical Monitor)


    Recently, we discovered that a splitting of the whispering gallery modes (WGMs) occurs in coupled resonator optical waveguides (CROWs), and that these split modes are of a higher Q than the single-resonator modes, leading to enormous circulating intensity magnification factors that dramatically reduce thresholds for nonlinear optical (NLO) processes. As a result of the enhancements in Q, pulses propagating at a split resonance can propagate much slower (faster) for over (under)-coupled structures, due to the modified dispersion near the split resonance. Moreover, when loss is considered, the mode-splitting may be thought of as analogous to the Autler-Townes splitting that occurs in atomic three-level lambda systems, i.e., it gives rise to induced transparency as a result of destructive interference. In under- or over-coupled CROWs, this coupled resonator induced transparency (CRIT) allows slow light to be achieved at the single-ring resonance with no absorption, while maintaining intensities such that NLO effects are maximized. The intensity magnification of the circulating fields and phase transfer characteristics are examined in detail.

  14. High index ring resonator coupled to UV-written waveguide

    DEFF Research Database (Denmark)

    Svendsen, Winnie Edith; Philipp, Hugh Taylor; Svalgaard, Mikael


    High index silicon rich nitride (SHN) ring resonators were coupled to straight UV-written waveguides. Resonance peaks with a free spectral range of 2 nm and a spectral width (fwhm) of 0.2 nm were observed......High index silicon rich nitride (SHN) ring resonators were coupled to straight UV-written waveguides. Resonance peaks with a free spectral range of 2 nm and a spectral width (fwhm) of 0.2 nm were observed...

  15. Superconducting coplanar waveguide resonators for electron spin resonance applications (United States)

    Sigillito, A. J.; Jock, R. M.; Tyryshkin, A. M.; Malissa, H.; Lyon, S. A.


    Superconducting coplanar waveguide (CPW) resonators are a promising alternative to conventional volume resonators for electron spin resonance (ESR) experiments where the sample volume and thus the number of spins is small. However, the magnetic fields required for ESR could present a problem for Nb superconducting resonators, which can be driven normal. Very thin Nb films (50 nm) and careful alignment of the resonators parallel to the magnetic field avoid driving the Nb normal, but flux trapping can still be an issue. Trapped flux reduces the resonator Q-factor, can lead to resonant frequency instability, and can lead to magnetic field inhomogeneities. At temperatures of 1.9 K and in a magnetic field 0.32 T, we have tested X-band resonators fabricated directly on the surface of a silicon sample. Q-factors in excess of 15,000 have been obtained. A thin layer of GE varnish applied directly to the resonator has been used to glue a sapphire wafer to its surface, and we still find Q-factors of 16,000 or more in the 0.32 T field. ESR applications of these resonators will be discussed. Supported in part by the ARO.

  16. Hybrid fiber resonator employing LRSPP waveguide coupler for gyroscope. (United States)

    Qian, Guang; Fu, Xing-Chang; Zhang, Li-Jiang; Tang, Jie; Liu, Yi-Ran; Zhang, Xiao-Yang; Zhang, Tong


    Polarization error and temperature noise are two main limits to the performance of resonant fiber optic gyroscope (RFOG). To overcome these limits, we demonstrated a hybrid resonator consisting of a polymer-based long-range surface plasmon polariton (LRSPP) waveguide coupler and a silica fiber. Single-polarization property of LRSPP waveguide and the offsetting of the opposite thermo-optical characteristics between the polymer-based LRSPP waveguide and the silica fiber can effectively inhibit both the polarization error and the temperature noise of RFOG. The measured resonance spectrum of the hybrid resonator shows the absence of polarization noise. The temperature dependence of wavelength shift (TDWS) of resonator dropped to about 2 pm/°C, or even to 0 pm/°C with optimal structure, which dramatically improves the temperature stability of gyroscope system. In addition, the hybrid resonator also shows tremendous application potential in rate-grade and tactical-grade gyroscopes.

  17. Waveguide volume probe for magnetic resonance imaging and spectroscopy

    DEFF Research Database (Denmark)


    The present disclosure relates to a probe for use within the field of nuclear magnetic resonance, such as magnetic resonance imaging (MRI), and magnetic resonance spectroscopy (MRS)). One embodiment relates to an RF probe for magnetic resonance imaging and/or spectroscopy comprising a conductive...... non-magnetic hollow waveguide having an internal volume and at least one open end, one or more capacitors and at least a first conductive non-magnetic wire, wherein said first conductive wire connects at least one of said one or more capacitors to opposite walls of one open end of the waveguide...... and wherein said first conductive wire and said one or more capacitors are located outside of said internal volume, wherein the internal volume of the hollow waveguide defines an imaging volume or sample volume....

  18. Resonant Tunneling in Photonic Double Quantum Well Heterostructures

    Directory of Open Access Journals (Sweden)

    Cox Joel


    Full Text Available Abstract Here, we study the resonant photonic states of photonic double quantum well (PDQW heterostructures composed of two different photonic crystals. The heterostructure is denoted as B/A/B/A/B, where photonic crystals A and B act as photonic wells and barriers, respectively. The resulting band structure causes photons to become confined within the wells, where they occupy discrete quantized states. We have obtained an expression for the transmission coefficient of the PDQW heterostructure using the transfer matrix method and have found that resonant states exist within the photonic wells. These resonant states occur in split pairs, due to a coupling between degenerate states shared by each of the photonic wells. It is observed that when the resonance energy lies at a bound photonic state and the two photonic quantum wells are far away from each other, resonant states appear in the transmission spectrum of the PDQW as single peaks. However, when the wells are brought closer together, coupling between bound photonic states causes an energy-splitting effect, and the transmitted states each have two peaks. Essentially, this means that the system can be switched between single and double transparent states. We have also observed that the total number of resonant states can be controlled by varying the width of the photonic wells, and the quality factor of transmitted peaks can be drastically improved by increasing the thickness of the outer photonic barriers. It is anticipated that the resonant states described here can be used to develop new types of photonic-switching devices, optical filters, and other optoelectronic devices.

  19. Optimization of Coplanar Waveguide Resonators for ESR Studies on Metals (United States)

    Clauss, Conrad; Dressel, Martin; Scheffler, Marc


    We present simulations and analytic calculations of the electromagnetic microwave fields of coplanar waveguide (CPW) resonators in the vicinity of highly conducting metallic samples. The CPW structures are designed with the aim of investigating electron spin resonance (ESR) in metallic heavy-fermion systems, in particular YbRh2Si2, close to the quantum critical point. Utilizing CPW resonators for ESR experiments allows for studies at mK temperatures and a wide range of freely selectable frequencies. It is therefore of great interest to evaluate the performance of resonant CPW structures with nearby metallic samples. Here we study the microwave fields at the sample surface as a function of sample distance from the waveguide structure and analyze the implications of the sample on the performance of the resonator. The simulation results reveal an optimum sample distance for which the microwave magnetic fields at the sample are maximized and thus best suited for ESR studies.

  20. Fano resonance in graphene-MoS2 heterostructure-based surface plasmon resonance biosensor and its potential applications (United States)

    Zheng, Gaige; Zou, Xiujuan; Chen, Yunyun; Xu, Linhua; Rao, Weifeng


    We propose a new configuration of surface plasmon resonance (SPR) sensor that is based on graphene-MoS2 hybrid structures for ultrasensitive detection of molecules. The present configuration is consisted of chalcogenide glass (2S2G) prism, Ag, coupling layer, guiding layer, graphene-MoS2 heterostructure and analyte. We perform numerical and analytical study of the impact of the thickness and refractive index (RI) of the coupling and guiding layer in a planar sensing structure within the Kretschmann configuration on the resonance properties of the excitation. Results of reflectivity calculations clearly demonstrate the sharp Fano-type resonance appears in the curve of SPR because of the coupling between surface plasmon polariton (SPP) and planar waveguide (PWG) modes. The properties of the Fano resonance (FR) strongly depend on the parameters of the structure. The calculated magnetic field profiles manifest that the hybrid nature of the electromagnetic (EM) modes excited in the present structure. The proposed system displays an enhancement factor of sensitivity by intensity more than 2 × 103-fold when compared to the SPR sensing scheme.

  1. Resonant modal conversion in a two-mode waveguide


    Boucher, Yann,; Parini, Alberto; Féron, Patrice


    International audience; We characterize a system consisting of a two-mode waveguide coupled to a single-mode microring resonator possibly presenting a nonlinear response of Kerr type. By using the scattering parameter formalism extended to the multimode domain, we show that in the linear regime and for an ideally transparent medium, each resonance of the system can be exploited to perform complete even-to-odd (respectively, odd-to-even) modal conversion. Moreover, when the Kerr nonlinearity i...

  2. Dielectric Resonator Nanoantenna Coupled To Metallic Coplanar Waveguide


    Malheiros-Silveira; Gilliard N.; Hernandez-Figueroa; Hugo E.


    A proposal about a dielectric resonator nanoantenna applied to couple optical beams to a surface plasmon coplanar waveguide (SP CPW), and vice versa, was theoretically investigated. The effects of this device operating in optical frequencies were studied, taking into account the central frequency of the conventional optical communication spectrum (C-band). Numerical results show that this proposal is interesting in that it couples an optical beam with an SP CPW with a good reflection coeffici...

  3. Optimized coplanar waveguide resonators for a superconductor–atom interface

    Energy Technology Data Exchange (ETDEWEB)

    Beck, M. A., E-mail:; Isaacs, J. A.; Booth, D.; Pritchard, J. D.; Saffman, M.; McDermott, R. [Department of Physics, University Of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706 (United States)


    We describe the design and characterization of superconducting coplanar waveguide cavities tailored to facilitate strong coupling between superconducting quantum circuits and single trapped Rydberg atoms. For initial superconductor–atom experiments at 4.2 K, we show that resonator quality factors above 10{sup 4} can be readily achieved. Furthermore, we demonstrate that the incorporation of thick-film copper electrodes at a voltage antinode of the resonator provides a route to enhance the zero-point electric fields of the resonator in a trapping region that is 40 μm above the chip surface, thereby minimizing chip heating from scattered trap light. The combination of high resonator quality factor and strong electric dipole coupling between the resonator and the atom should make it possible to achieve the strong coupling limit of cavity quantum electrodynamics with this system.

  4. Optical pulling force and conveyor belt effect in resonator-waveguide system. (United States)

    Intaraprasonk, Varat; Fan, Shanhui


    We present the theoretical condition and actual numerical design that achieves an optical pulling force in resonator-waveguide systems, where the direction of the force on the resonator is in the opposite direction to the input light in the waveguide. We also show that this pulling force can occur in conjunction with the lateral optical equilibrium effect, such that the resonator is maintained at the fixed distance from the waveguide while experiencing the pulling force.

  5. Tunable Fano and coupled-resonator-induced transparency resonances in the waveguide-coupled inverted nested ring resonator (United States)

    Yu, Changqiu; Tian, He; Qian, Zhenghong; Bai, Ru; Zhu, Liyao; Zhang, Yundong


    A waveguide-coupled inverted nested ring resonator structure is proposed and theoretically investigated. The effects of the parameters of such a structure on its transmission properties are demonstrated. Results show that both Fano resonance and coupled-resonator-induced transparency (CRIT) spectra can be produced within this structure, depending on the length ratio of the feedback waveguide and ring. In addition, the slope of the Fano resonance can be tuned and reversed by varying coupling coefficients and effective refractive index. Besides, CRIT-based tunable group delay can be obtained with high transmittance. Therefore, this structure has potential applications in optical sensors and optical communication.

  6. Temperature Dependence of the Resonant Magnetoelectric Effect in Layered Heterostructures

    Directory of Open Access Journals (Sweden)

    Dmitrii A. Burdin


    Full Text Available The dependence of the resonant direct magnetoelectric effect on temperature is studied experimentally in planar composite structures. Samples of rectangular shapes with dimensions of 5 mm × 20 mm employed ferromagnetic layers of either an amorphous (metallic glass alloy or nickel with a thickness of 20–200 μm and piezoelectric layers of single crystalline langatate material or lead zirconate titanate piezoelectric ceramics with a thickness of 500 μm. The temperature of the samples was varied in a range between 120 and 390 K by blowing a gaseous nitrogen stream around them. It is shown that the effective characteristics of the magnetoelectric effect—such as the mechanical resonance frequency fr, the quality factor Q and the magnitude of the magnetoelectric coefficient αE at the resonance frequency—are contingent on temperature. The interrelations between the temperature changes of the characteristics of the magnetoelectric effect and the temperature variations of the following material parameters—Young’s modulus Y, the acoustic quality factor of individual layers, the dielectric constant ε, the piezoelectric modulus d of the piezoelectric layer as well as the piezomagnetic coefficients λ(n of the ferromagnetic layer—are established. The effect of temperature on the characteristics of the nonlinear magnetoelectric effect is observed for the first time. The results can be useful for designing magnetoelectric heterostructures with specified temperature characteristics, in particular, for the development of thermally stabilized magnetoelectric devices.

  7. Gate-Controlled Electron Spin Resonance in a GaAs/AlGaAs Heterostructure


    Jiang, H. W.; Yablonovitch, E.


    The electron spin resonance (ESR) of two-dimensional electrons is investigated in a gated GaAs/AlGaAs heterostructure. We found that the ESR resonance frequency can be turned by means of a gate voltage. The front and back gates of the heterostructure produce opposite g-factor shift, suggesting that electron g-factor is being electrostatically controlled by shifting the equilibrium position of the electron wave function from one epitaxial layer to another with different g-factors.

  8. Resonance-enhanced waveguide-coupled silicon-germanium detector

    CERN Document Server

    Alloatti, Luca


    A photodiode with 0.55$\\pm$0.1 A/W responsivity at a wavelength of 1176.9 nm has been fabricated in a 45 nm microelectronics silicon-on-insulator foundry process. The resonant waveguide photodetector exploits carrier generation in silicon-germanium (SiGe) within a microring which is compatible with high-performance electronics. A 3 dB bandwidth of 5 GHz at -4 V bias is obtained with a dark current of less than 20 pA.

  9. Performance of ultracompact copper-capped silicon hybrid plasmonic waveguide-ring resonators at telecom wavelengths. (United States)

    Zhu, Shiyang; Lo, G Q; Kwong, D L


    Ultracompact Cu-capped Si hybrid plasmonic waveguide-ring resonators (WRRs) with ring radii of 1.09-2.59 μm are fabricated on silicon on insulator substrates using standard complementary metal-oxide-semiconductor technology and characterized over the telecom wavelength range of 1.52-1.62 μm. The dependence of the spectral characteristics on the key structural parameters such as the Si core width, the ring radius, the separation gap between the ring and bus waveguides, and the ring configuration is systematically studied. A WRR with 2.59-μm radius and 0.250-μm nominal gap exhibits good performances such as normalized insertion loss of ~0.1 dB, extinction ratio of ~12.8 dB, free spectral range of ~47 nm, and quality factor of ~275. The resonance wavelength is redshifted by ~4.6 nm and an extinction ratio of ~7.5 dB is achieved with temperature increasing from 27 to 82°C. The corresponding effective thermo-optical coefficient (dn(g)/dT) is estimated to be ~1.6 × 10(-4) K(-1), which is contributed by the thermo-optical effect of both the Si core and the Cu cap, as revealed by numerical simulations. Combined with the compact size and the high thermal conductivity of Cu, various effective thermo-optical devices based on these Cu-capped plasmonic WRRs could be realized for seamless integration in existing Si electronic-photonic integrated circuits.

  10. Cutoff-mesa isolated rib optical waveguide for III-V heterostructure photonic integrated circuits (United States)

    Vawter, G.A.; Smith, R.E.


    A cutoff mesa rib waveguide provides single-mode performance regardless of any deep etches that might be used for electrical isolation between integrated electrooptic devices. Utilizing a principle of a cutoff slab waveguide with an asymmetrical refractive index profile, single mode operation is achievable with a wide range of rib widths and does not require demanding etch depth tolerances. This new waveguide design eliminates reflection effects, or self-interference, commonly seen when conventional rib waveguides are combined with deep isolation etches and thereby reduces high order mode propagation and crosstalk compared to the conventional rib waveguides. 7 figs.

  11. Slow waves in locally resonant metamaterials line defect waveguides. (United States)

    Kaina, Nadège; Causier, Alexandre; Bourlier, Yoan; Fink, Mathias; Berthelot, Thomas; Lerosey, Geoffroy


    Many efforts have been devoted to wave slowing, as it is essential, for instance, in analog signal computing and is one prerequisite for increased wave/matter interactions. Despite the interest of many communities, researches have mostly been conducted in optics, where wavelength-scaled structured composite media are promising candidates for compact slow light components. Yet their structural scale prevents them from being transposed to lower frequencies. Here, we propose to overcome this limitation using the deep sub-wavelength scale of locally resonant metamaterials. We experimentally show, in the microwave regime, that introducing coupled resonant defects in such metamaterials creates sub-wavelength waveguides in which wave propagation exhibit reduced group velocities. We qualitatively explain the mechanism underlying this slow wave propagation and demonstrate how it can be used to tune the velocity, achieving group indices as high as 227. We conclude by highlighting the three beneficial consequences of our line defect slow wave waveguides: (1) the sub-wavelength scale making it a compact platform for low frequencies (2) the large group indices that together with the extreme field confinement enables efficient wave/matter interactions and (3) the fact that, contrarily to other approaches, slow wave propagation does not occur at the expense of drastic bandwidth reductions.

  12. Brillouin resonance broadening due to structural variations in nanoscale waveguides

    CERN Document Server

    Wolff, Christian; Steel, Michael J; Eggleton, Benjamin J; Poulton, Christopher G


    We study the impact of structural variations (that is slowly varying geometry aberrations and internal strain fields) on the resonance width and shape of stimulated Brillouin scattering (SBS) in nanoscale waveguides. We find that they lead to an inhomogeneous resonance broadening through two distinct mechanisms: firstly, the acoustic frequency is directly influenced via mechanical nonlinearities; secondly, the optical wave numbers are influenced via the opto-mechanical nonlinearity leading to an additional acoustic frequency shift via the phase-matching condition. We find that this second mechanism is proportional to the opto-mechanical coupling and, hence, related to the SBS-gain itself. It is absent in intra-mode forward SBS, while it plays a significant role in backward scattering. In backward SBS increasing the opto-acoustic overlap beyond a threshold defined by the fabrication tolerances will therefore no longer yield the expected quadratic increase in overall Stokes amplification. Our results can be tra...

  13. Resonant transport of light from planar polymer waveguide into liquid-crystal microcavity. (United States)

    Jampani, V S R; Humar, M; Muševič, I


    We demonstrate the resonant transfer of light from a planar waveguide to a nematic liquid-crystal microdroplet immersed in water. A wide spectrum of light from a supercontinuum laser source is coupled into a high-refractive-index polymer waveguide using a prism-film coupler. The waveguide is in contact with a water dispersion of droplets from the nematic liquid-crystal 5CB. The evanescent field of the light in the waveguide is resonantly coupled to the whispering-gallery mode resonances, sustained by 5 - 20 μm-sized nematic liquid-crystal droplets, which are in close proximity to the waveguide. The resonant transfer of light is tuned by the temperature-induced shifting of the WGM resonances due to the temperature dependence of the refractive index of the nematic liquid crystal. The measurements are compared to the calculations of the coupled-mode theory.

  14. Characterization of coplanar waveguide resonators made of nitride superconductors (United States)

    Terai, Hirotaka; Tokyo University Collaboration

    Superconducting coplanar waveguide (CPW) resonator is a key component of superconducting electromagnetic field detectors and superconducting qubits based on circuit quantum electrodynamics (QED), where a high quality factor is desirable for applications. We have previously reported superconducting transmon qubits based on fullyepitaxial NbN/AlN/NbN tunnel junctions grown on a MgO substrate. However, the internal quality factor of the superconducting CPW resonator made of a (100) NbN film were at most several thousands, suggesting the existence of a loss mechanism coming from the MgO substrate or the interfacial two-level-systems (TLS). To clarify the origin of the loss mechanisms in superconducting CPW resonators, we systematically investigated the dependences on substrate materials, deposition conditions of nitride superconductors, and surface treatment conditions prior to the deposition. CPW resonators made of NbN or TiN deposited on a hydrogenterminated silicon substrate without any surface treatment showed a high internal quality factor above one million at the microwave power of a single photon level. Our results support that loss in superconducting resonators is dominated by TLS at the interface between the superconductor and the substrate. This research was partly supported by JST, ERATO.

  15. Resonant tunneling quantum waveguides of variable cross-section, asymptotics, numerics, and applications

    CERN Document Server

    Baskin, Lev; Plamenevskii, Boris; Sarafanov, Oleg


    This volume studies electron resonant tunneling in two- and three-dimensional quantum waveguides of variable cross-sections in the time-independent approach. Mathematical models are suggested for the resonant tunneling and develop asymptotic and numerical approaches for investigating the models. Also, schemes are presented for several electronics devices based on the phenomenon of resonant tunneling.   Devices based on the phenomenon of electron resonant tunneling are widely used in electronics. Efforts are directed towards refining properties of resonance structures. There are prospects for building new nanosize electronics elements based on quantum dot systems.   However, the role of resonance structure can also be given to a quantum wire of variable cross-section. Instead of an "electrode - quantum dot - electrode" system, one can use a quantum wire with two narrows. A waveguide narrow is an effective potential barrier for longitudinal electron motion along a waveguide. The part of the waveguide between ...

  16. Silica waveguide-type ring resonators for resonant micro-optic gyroscopes (United States)

    Lin, Yi; Zhang, Jianjie; Li, Hanzhao; Ma, Huilian; Jin, Zhonghe


    The resonant micro-optic gyroscope (RMOG) is an attractive candidate for inertial rotation sensors requiring small, light and robust gyros. A high-performance RMOG needs a low-loss and high finesse waveguide-type ring resonator (WRR). Two general configurations of the WRRs which are made of Ge-doped silica core waveguides based on plasma enhanced chemical vapor deposition including the reflector-type and the transmitter-type are introduced. The reflector-type WRR with a length of 7.9 cm and a diameter of 2.5 cm has a finesse of 196.7 and a resonant depth of 98%. In addition, it's pigtailed with single-polarization fiber to reduce the polarization error. The transmitter-type WRR with a length of 15.9 cm and a diameter of 5.06 cm has a finesse of 128 and a resonant depth of 95%. The waveguide loss low as 0.007 dB/cm has been measured, leading to the shot-noise limited sensitivity of 1.0°/h when the average optical power at the input of the photodetector is 1 mW and the detecting bandwidth is 1 Hz.

  17. Integrated optical gyroscope using active long-range surface plasmon-polariton waveguide resonator. (United States)

    Zhang, Tong; Qian, Guang; Wang, Yang-Yang; Xue, Xiao-Jun; Shan, Feng; Li, Ruo-Zhou; Wu, Jing-Yuan; Zhang, Xiao-Yang


    Optical gyroscopes with high sensitivity are important rotation sensors for inertial navigation systems. Here, we present the concept of integrated resonant optical gyroscope constructed by active long-range surface plasmon-polariton (LRSPP) waveguide resonator. In this gyroscope, LRSPP waveguide doped gain medium is pumped to compensate the propagation loss, which has lower pump noise than that of conventional optical waveguide. Peculiar properties of single-polarization of LRSPP waveguide have been found to significantly reduce the polarization error. The metal layer of LRSPP waveguide is electro-optical multiplexed for suppression of reciprocal noises. It shows a limited sensitivity of ~10(-4) deg/h, and a maximum zero drift which is 4 orders of magnitude lower than that constructed by conventional single-mode waveguide.

  18. Refractive Index Sensor Based on Fano Resonances in Metal-Insulator-Metal Waveguides Coupled with Resonators

    Directory of Open Access Journals (Sweden)

    Yue Tang


    Full Text Available A surface plasmon polariton refractive index sensor based on Fano resonances in metal–insulator–metal (MIM waveguides coupled with rectangular and ring resonators is proposed and numerically investigated using a finite element method. Fano resonances are observed in the transmission spectra, which result from the coupling between the narrow-band spectral response in the ring resonator and the broadband spectral response in the rectangular resonator. Results are analyzed using coupled-mode theory based on transmission line theory. The coupled mode theory is employed to explain the Fano resonance effect, and the analytical result is in good agreement with the simulation result. The results show that with an increase in the refractive index of the fill dielectric material in the slot of the system, the Fano resonance peak exhibits a remarkable red shift, and the highest value of sensitivity (S is 1125 nm/RIU, RIU means refractive index unit. Furthermore, the coupled MIM waveguide structure can be integrated with other photonic devices at the chip scale. The results can provide a guide for future applications of this structure.

  19. Steering and filtering white light with resonant waveguide gratings (United States)

    Quaranta, Giorgio; Basset, Guillaume; Martin, Olivier J. F.; Gallinet, Benjamin


    A novel thin-film single-layer structure based on resonant waveguide gratings (RWGs) allows to engineer selective color filtering and steering of white light. The unit cell of the structure consists of two adjacent finite-length and cross-talking RWGs, where the former acts as in-coupler and the latter acts as out-coupler. The structure is made by only one nano-imprint lithography replication and one thin film layer deposition, making it fully compatible with up-scalable fabrication processes. We characterize a fabricated optical security element designed to work with the flash and the camera of a smartphone in off-axis light steering configuration, where the pattern is revealed only by placing the smartphone in the proper position. Widespread applications are foreseen in a variety of fields, such as multifocal or monochromatic lenses, solar cells, biosensors, security devices and seethrough optical combiners for near-eye displays.

  20. Theory and Applications of Surface Plasmon Resonance, Resonant Mirror, Resonant Waveguide Grating, and Dual Polarization Interferometry Biosensors

    Directory of Open Access Journals (Sweden)

    Billy W. Day


    Full Text Available Biosensors have been used extensively in the scientific community for several purposes, most notably to determine association and dissociation kinetics, protein-ligand, protein-protein, or nucleic acid hybridization interactions. A number of different types of biosensors are available in the field, each with real or perceived benefits over the others. This review discusses the basic theory and operational arrangements of four commercially available types of optical biosensors: surface plasmon resonance, resonant mirror, resonance waveguide grating, and dual polarization interferometry. The different applications these techniques offer are discussed from experiments and results reported in recently published literature. Additionally, recent advancements or modifications to the current techniques are also discussed.

  1. Analysis of the effect of a rectangular cavity resonator on acoustic wave transmission in a waveguide (United States)

    Porter, R.; Evans, D. V.


    The transmission of acoustic waves along a two-dimensional waveguide which is coupled through an opening in its wall to a rectangular cavity resonator is considered. The resonator acts as a classical band-stop filter, significantly reducing acoustic transmission across a range of frequencies. Assuming wave frequencies below the first waveguide cut-off, the solution for the reflected and transmitted wave amplitudes is formulated exactly within the framework of inviscid linear acoustics. The main aim of the paper is to develop an approximation in closed form for reflected and transmitted amplitudes when the gap in the thin wall separating the waveguide and the cavity resonator is assumed to be small. This approximation is shown to accurately capture the effect of all cavities resonances, not just the fundamental Helmholtz resonance. It is envisaged this formula (and more generally the mathematical approach adopted) could be used in the development of acoustic metamaterial devices containing resonator arrays.

  2. High finesse silica waveguide ring resonators for resonant micro-optic gyroscopes (United States)

    Zhang, Jianjie; Li, Hanzhao; Ma, Huilian; Jin, Zhonghe


    A high-finesse silica waveguide ring resonator (WRR) is designed and a new record is demonstrated experimentally. The finesse and the resonant depth of the silica WRR with a length of 7.9 cm and a diameter of 2.5 cm are 196.7 and 98%, respectively. In addition, the silica WRR is pigtailed with single-polarization fiber to improve the polarization extinction ratio thus to reduce the polarization error. With the application of this high-finesse and high polarization extinction ratio WRR to the resonant micro-optic gyroscope (RMOG), a bias stability of 0.004°/s was observed over a one-hour timeframe.

  3. Atomically thin resonant tunnel diodes built from synthetic van der Waals heterostructures

    KAUST Repository

    Lin, Yu-Chuan


    Vertical integration of two-dimensional van der Waals materials is predicted to lead to novel electronic and optical properties not found in the constituent layers. Here, we present the direct synthesis of two unique, atomically thin, multi-junction heterostructures by combining graphene with the monolayer transition-metal dichalcogenides: molybdenum disulfide (MoS2), molybdenum diselenide (MoSe2) and tungsten diselenide (WSe2). The realization of MoS2–WSe2–graphene and WSe2–MoS2–graphene heterostructures leads to resonant tunnelling in an atomically thin stack with spectrally narrow, room temperature negative differential resistance characteristics.

  4. Controllable coupling between a nanomechanical resonator and a coplanar-waveguide resonator via a superconducting flux qubit


    Xiong, Wei; Jin, Da-Yu; Jing, Jun; Lam, Chi-Hang; You, J. Q.


    We study a tripartite quantum system consisting of a coplanar-waveguide (CPW) resonator and a nanomechanical resonator (NAMR) connected by a flux qubit, where the flux qubit has a large detuning from both resonators. By a unitray transformation and a second-order approximation, we obtain a strong and controllable (i.e., magnetic-field-dependent) effective coupling between the NAMR and the CPW resonator. Due to the strong coupling, vacuum Rabi splitting can be observed from the voltage-fluctua...

  5. Submicron optical waveguides and microring resonators fabricated by selective oxidation of tantalum. (United States)

    Rabiei, Payam; Ma, Jichi; Khan, Saeed; Chiles, Jeff; Fathpour, Sasan


    Submicron tantalum pentoxide ridge and channel optical waveguides and microring resonators are demonstrated on silicon substrates by selective oxidation of the refractory metal, tantalum. The novel method eliminates the surface roughness problem normally introduced during dry etching of waveguide sidewalls and also simplifies fabrication of directional couplers. It is shown that the measured propagation loss is independent of the waveguide structure and thereby limited by the material loss of tantalum pentoxide in waveguides core regions. The achieved microring resonators have cross-sectional dimensions of ~600 nm × ~500 nm, diameters as small as 80 µm with a quality, Q, factor of 4.5 × 10(4), and a finesse of 120.

  6. Numerical simulations of surface plasmon resonances in metal-chalcogenide waveguides (United States)

    Stafe, Mihai; Vasile, Georgiana C.; Popescu, Aurelian A.; Savastru, Dan; Baschir, Laurentiu; Mihailescu, Mona; Negutu, Constantin; Puscas, Niculae N.


    In this paper we present several numerical simulations of the surface plasmon resonance for Kretschmann type configuration in a metal-chalcogenide waveguide. We assume that the chalcogenide (GaLaS) waveguide layer have finite thickness, whereas the gold film layer and the air cover layer are semi-infinite layers (from an optical point of view). We determined the thickness of the chalcogenide film for which plasmonic resonant coupling of the incident radiation to the waveguide occurs. We calculated the propagation constant for the TE- and TM- modes (both for visible and IR domain), the attenuation coefficient and the electromagnetic field distribution within the waveguide. The obtained results provide the conditions for design an optical memory device 2D based on light-light interaction in plasmonic configuration.

  7. Sensitive spin detection using an on-chip SQUID-waveguide resonator (United States)

    Yue, G.; Chen, L.; Barreda, J.; Bevara, V.; Hu, L.; Wu, L.; Wang, Z.; Andrei, P.; Bertaina, S.; Chiorescu, I.


    Precise detection of spin resonance is of paramount importance to achieve coherent spin control in quantum computing. We present a setup for spin resonance measurements, which uses a dc-SQUID flux detector coupled to an antenna from a coplanar waveguide. The SQUID and the waveguide are fabricated from a 20 nm Nb thin film, allowing high magnetic field operation with the field applied parallel to the chip. We observe a resonance signal between the first and third excited states of Gd spins S = 7/2 in a CaWO4 crystal, relevant for state control in multi-level systems.

  8. Design of a Label-Free, Distributed Bragg Grating Resonator Based Dielectric Waveguide Biosensor

    Directory of Open Access Journals (Sweden)

    Florian Kehl


    Full Text Available In this work, we present a resonant, dielectric waveguide device based on distributed Bragg gratings for label-free biosensing applications. The refractive index sensitive optical transducer aims at improving the performance of planar waveguide grating sensor systems with limited Q-factor and dynamic range by combing the advantages of resonant cavities, such as a multitude of resonance peaks with high finesse, with the manageable complexity of waveguide grating couplers. The general sensor concept is introduced and supported by theoretical considerations as well as numerical simulations based on Coupled Mode Theory. In contrast to a single Bragg grating reflector, the presented Fabry-Pérot type distributed Bragg resonator exhibits an extended measurement range as well as relaxed fabrication tolerances. The resulting, relatively simple sensor structure can be fabricated with standard lithographic means and is independent of expensive light-sources and/or detectors, making an affordable but sensitive device, potentially suitable for point-of-care applications.

  9. Gain enhanced Fano resonance in a coupled photonic crystal cavity-waveguide structure (United States)

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


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

  10. Gain enhanced Fano resonance in a coupled photonic crystal cavity-waveguide structure. (United States)

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


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

  11. Novel implementation of dual-band bandstop waveguide filter using quarter-wave resonators

    Directory of Open Access Journals (Sweden)

    Mrvić Marija V.


    Full Text Available Novel implementation of microwave waveguide filter with two rejection bands is presented in this paper. Quarter-wave resonators are implemented in planar technology, and in the research, they are used as resonant septa inserted in the waveguide. Resonators with single resonant frequency are considered, as well as their equivalent circuits. The observed resonator responses are analyzed in details, in order to design second-order filter with a single rejection band. Mutual coupling between the resonators on the same printed-circuit insert is investigated. The second-order filter with two stopbands is implemented using observed resonators and the proposed method for filter design. The proposed method for filter design opens possibility for realization of higher order filters with multi-stopbands.

  12. Gate-controlled electron spin resonance in GaAs/AlxGa1-xAs heterostructures (United States)

    Jiang, H. W.; Yablonovitch, Eli


    The electron spin resonance (ESR) of two-dimensional electrons is investigated in a gated GaAs/AlGaAs heterostructure. We found that the ESR resonance frequency can be tuned by means of a gate voltage. The front and back gates of the heterostructure produce opposite g-factor shift, suggesting that electron g factor is being electrostatically controlled by shifting the equilibrium position of the electron wave function from one epitaxial layer to another with different g factors.

  13. Slow light enhanced correlated photon pair generation in photonic-crystal coupled-resonator optical waveguides. (United States)

    Matsuda, Nobuyuki; Takesue, Hiroki; Shimizu, Kaoru; Tokura, Yasuhiro; Kuramochi, Eiichi; Notomi, Masaya


    We demonstrate the generation of quantum-correlated photon pairs from a Si photonic-crystal coupled-resonator optical waveguide. A slow-light supermode realized by the collective resonance of high-Q and small-mode-volume photonic-crystal cavities successfully enhanced the efficiency of the spontaneous four-wave mixing process. The generation rate of photon pairs was improved by two orders of magnitude compared with that of a photonic-crystal line defect waveguide without a slow-light effect.

  14. Two-Dimensional Cavity Resonant Modes of Si Based Bragg Reflection Ridge Waveguide (United States)

    Chen, San; Lu, Hong-Yan; Chen, Kun-Ji; Xu, Jun; Ma, Zhong-Yuan; Li, Wei; Huang, Xin-Fan


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

  15. Cyclotron resonance in InAs/GaSb heterostructure in inclined magnetic field

    CERN Document Server

    Greshnov, A A; Vasilev, Yu B; Suchalkin, S D; Meltser, B Y; Ivanov, S V; Kopev, P S


    The mechanism of splitting the cyclotron resonance line in the InAs/GaSb heterostructure in the inclined magnetic field is experimentally and theoretically studied. It is shown that the electrons and holes mixing in leads to the anticrossing Landau levels and consequently to the cyclotron resonance line splitting. Splitting in the case of the inclined magnetic field was not observed which is explained by damping the electrons and holes states mixing in on the account of originating the additional barrier for the electrons and holes by availability of the magnetic field longitudinal constituent

  16. Chirped self-similar optical pulses in tapered centrosymmetric nonlinear waveguides doped with resonant impurities (United States)

    He, J. R.; Xu, S. L.; Xue, L.


    Exact chirped self-similar optical pulses propagating in tapered centrosymmetric nonlinear waveguides doped with resonant impurities are reported. The propagation behaviors of the pulses are studied by tailoring of the tapering function. Numerical simulations and stability analysis reveal that the tapering can be used to postpone the wave dispersion and the addition of a small cubic self-focusing term to the governing equation could stabilize the chirped bright pulses. An example of possible experimental protocol that may generate the pulses in realistic waveguides is given. The obtained chirped self-similar optical pulses are particularly useful in the design of amplifying or attenuating pulse compressors for chirped solitary waves in tapered centrosymmetric nonlinear waveguides doped with resonant impurities.

  17. Modeling of mode-locked coupled-resonator optical waveguide lasers

    DEFF Research Database (Denmark)

    Agger, Christian; Skovgård, Troels Suhr; Gregersen, Niels


    Coupled-resonator optical waveguides made from coupled high-Q photonic crystal nanocavities are investigated for use as cavities in mode-locked lasers. Such devices show great potential in slowing down light and can serve to reduce the cavity length of a mode-locked laser. An explicit expression...

  18. Experimental characterization of dielectric-loaded plasmonic waveguide-racetrack resonators at near-infrared wavelengths

    DEFF Research Database (Denmark)

    Garcia, Cesar; Coello, Victor; Han, Zhanghua


    Dielectric-loaded plasmonic waveguide-racetrack resonators (WRTRs) were designed and fabricated for operating at near-infrared wavelengths (750–850 nm) and characterized using leakage-radiation microscopy. The transmission spectra of the WRTRs are found experimentally and compared to the calculat...

  19. Slow light enhanced optical nonlinearity in a silicon photonic crystal coupled-resonator optical waveguide. (United States)

    Matsuda, Nobuyuki; Kato, Takumi; Harada, Ken-Ichi; Takesue, Hiroki; Kuramochi, Eiichi; Taniyama, Hideaki; Notomi, Masaya


    We demonstrate highly enhanced optical nonlinearity in a coupled-resonator optical waveguide (CROW) in a four-wave mixing experiment. Using a CROW consisting of 200 coupled resonators based on width-modulated photonic crystal nanocavities in a line defect, we obtained an effective nonlinear constant exceeding 10,000 /W/m, thanks to slow light propagation combined with a strong spatial confinement of light achieved by the wavelength-sized cavities.

  20. High frequency resonant waveguide grating imager for assessing drug-induced cardiotoxicity (United States)

    Ferrie, Ann M.; Wu, Qi; Deichmann, Oberon D.; Fang, Ye


    We report a high-frequency resonant waveguide grating imager for assessing compound-induced cardiotoxicity. The imager sweeps the wavelength range from 823 nm to 838 nm every 3 s to identify and monitor compound-induced shifts in resonance wavelength and then switch to the intensity-imaging mode to detect the beating rhythm and proarrhythmic effects of compounds on induced pluripotent stem cell-derived cardiomyocytes. This opens possibility to study cardiovascular biology and compound-induced cardiotoxicity.

  1. Longitudinal Near-Field Coupling between Acoustic Resonators Grafted onto a Waveguide

    Directory of Open Access Journals (Sweden)

    Yan-Feng Wang


    Full Text Available We investigate longitudinal near-field coupling between acoustic resonators grafted along a waveguide. Experiments are performed in the audible range with a simple acoustic system composed of a finite aperiodic sequence of air resonators. Transmission typically shows a zero around a resonance frequency of a single resonator, as is well known. When two identical resonators are brought in close proximity, however, we observe that longitudinal near-field coupling strongly influences the acoustic transmission. When the separation between resonators is increased so that they can be considered in the far field of one another, we further observe the appearance of Fano-like transmission profiles. We explain this observation by the formation of locally resonant Fabry-Perot interferometers from every pair of resonators. All experimental results are compared to three-dimensional finite element analysis of the acoustic system.

  2. Superconducting properties of magnesium diboride thin film measured by using coplanar waveguide resonator

    Energy Technology Data Exchange (ETDEWEB)

    Žemlička, M., E-mail: [Department of Experimental Physics, Comenius University, SK-84248 Bratislava (Slovakia); Neilinger, P.; Trgala, M.; Gregor, M.; Plecenik, T.; Ďurina, P. [Department of Experimental Physics, Comenius University, SK-84248 Bratislava (Slovakia); Grajcar, M. [Department of Experimental Physics, Comenius University, SK-84248 Bratislava (Slovakia); Institute of Physics of Slovak Academy of Science, Dúbravská cesta, Bratislava (Slovakia)


    Highlights: • Study of the superconducting properties of granular disordered superconductor magnesium diboride (MgB{sub 2}). • Microwave measurements transmission properties of high-quality superconducting coplanar waveguide (CPW) resonator. • Temperature dependence of quality and resonant frequency of CPW resonator. • Hysteresis detuning of resonant frequency in changing magnetic field of artificially created RF superconducting quantum interference device (SQUID) coupled to CPW resonator. • SQUID-like behavior of CPW resonators made of granular disordered superconductors without any artificial structures in it. - Abstract: In this paper we demonstrate the superconducting properties of MgB{sub 2} coplanar waveguide resonator patterned from 300 nm thin film fabricated by vapor deposition. We measured the temperature dependence of the quality factor and the resonant frequency of the resonator. Surprisingly, we also observed hysteretic periodic response of resonance frequency to external magnetic field, which is characteristic of bistable systems with double-well potential, such as superconducting RF SQUID or phase-slip flux qubits. This property seems to be peculiar for granular and disordered superconductors where a superconducting loop of large effective diameter with weak links can be formed.

  3. A Refractive Index Sensor Based on a Metal-Insulator-Metal Waveguide-Coupled Ring Resonator

    Directory of Open Access Journals (Sweden)

    Shu-Bin Yan


    Full Text Available A refractive index sensor composed of two straight metal-insulator-metal waveguides and a ring resonator is presented. One end of each straight waveguide is sealed and the other end acts as port. The transmission spectrum and magnetic field distribution of this sensor structure are simulated using finite-difference time-domain method (FDTD. The results show that an asymmetric line shape is observed in the transmission spectrum, and that the transmission spectrum shows a filter-like behavior. The quality factor and sensitivity are taken to characterize its sensing performance and filter properties. How structural parameters affect the sensing performance and filter properties is also studied.

  4. The characterization of GH shifts of surface plasmon resonance in a waveguide using the FDTD method. (United States)

    Oh, Geum-Yoon; Kim, Doo Gun; Choi, Young-Wan


    We have explicated the Goos-Hänchen (GH) shift in a mum-order Kretchmann-Raether configuration embedded in an optical waveguide structure by using the finite-difference time-domain method. For optical waveguide-type surface plasmon resonance (SPR) devices, the precise derivation of the GH shift has become critical. Artmann's equation, which is accurate enough for bulk optics, is difficult to apply to waveguide-type SPR devices. This is because Artmann's equation, based on the differentiation of the phase shift, is inaccurate at the critical and resonance angles where drastic phase changes occur. In this study, we accurately identified both the positive and the negative GH shifts around the incidence angle of resonance. In a waveguide-type Kretchmann-Raether configuration with an Au thin film of 50 nm, positive and negative lateral shifts of -0.75 and + 1.0 microm are obtained on the SPR with the incident angles of 44.4 degrees and 47.5 degrees, respectively, at a wavelength of 632.8 nm.


    Directory of Open Access Journals (Sweden)



    Full Text Available We developed a biosensor that is capable for simultaneous surface plasmon resonance (SPR sensing and hyperspectral fluorescence analysis in this paper. A symmetrical metal-dielectric slab scheme is employed for the excitation of coupled plasmon waveguide resonance (CPWR in the present work. Resonance between surface plasmon mode and the guided waveguide mode generates narrower full width half-maximum of the reflective curves which leads to increased precision for the determination of refractive index over conventional SPR sensors. In addition, CPWR also offers longer surface propagation depths and higher surface electric field strengths that enable the excitation of fluorescence with hyperspectral technique to maintain an appreciable signal-to-noise ratio. The refractive index information obtained from SPR sensing and the chemical properties obtained through hyperspectral fluorescence analysis confirm each other to exclude false-positive or false-negative cases. The sensor provides a comprehensive understanding of the biological events on the sensor chips.

  6. Integrated microfluidic capillary in a waveguide resonator for chemical and biomedical sensing

    Energy Technology Data Exchange (ETDEWEB)

    Pavuluri, S K; Lopez-Villarroya, R; McKeever, E; Goussetis, G; Desmulliez, M P Y; Kavanagh, D, E-mail:, E-mail: [MIcroSystems Engineering Centre (MISEC), School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS (United Kingdom)


    A novel microfluidic sensing device based on waveguide cavity filters is proposed for the characterisation, detection of cells in solution and chemical substances in micro-litre volumes. The sensor consists of a micromachined microfluidic channel within a waveguide-based resonator localised increased near-fields and could potentially be designed for different frequency regimes to improve the sensitivity. The present sensor has been proposed for fabrication in different manufacturing platforms and an initial prototype with a 100mum micromachined channel that is embedded within an X-band E-plane waveguide has been fabricated and tested. The design methodology for the microfluidic channel and the E-plane filter is also presented.

  7. The spontaneous emission noise limit of active resonator optical waveguide gyroscope (United States)

    Li, Wenxiu; Zhang, Hao; Lin, Jian; Liu, Jiaming; Xue, Xia; Huang, Anping; Xiao, Zhisong


    Active resonators based on optical waveguides can significantly enhance the performance of optical gyroscope due to its loss compensation effect. The spontaneous emission noise (SEN) stemmed from optical gain will broaden the linewidth of the resonator and limit the sensitivity and resolution of active resonator optical gyroscope (AROG). In this paper, we modified the sensitivity formula when the spontaneous emission noise is dominant and analyzed theoretically the performance limitations of the AROG. After considering the spontaneous emission noise source, the resolution can be improved through optimizing the design parameters of the AROG

  8. Photon-induced thermal effects in superconducting coplanar waveguide resonators (United States)

    Wang, Yiwen; Zhou, Pinjia; Wei, Lianfu; Li, Haijie; Zhang, Beihong; Zhang, Miao; Wei, Qiang; Fang, Yurong; Cao, Chunhai


    We experimentally investigated the optical responses of a superconducting niobium resonator. It was found that, with increasing radiation power, the resonance frequency increases monotonically below around 500 mK, decreases monotonically above around 1 K, and exhibits a nonmonotonic behavior at around 700 mK. These observations show that one can operate the irradiated resonator in three temperature regimes, depending on whether two-level system (TLS) effects or kinetic inductance effects dominate. Furthermore, we found that the optical responses at ultra-low temperatures can be qualitatively regarded as a photon-induced thermalization effect of TLSs, which could be utilized to achieve thermal sensitive photon detections.

  9. Mini-stop bands in single heterojunction photonic crystal waveguides

    KAUST Repository

    Shahid, N.


    Spectral characteristics of mini-stop bands (MSB) in line-defect photonic crystal (PhC) waveguides and in heterostructure PhC waveguides having one abrupt interface are investigated. Tunability of the MSB position by air-fill factor heterostructure PhC waveguides is utilized to demonstrate different filter functions, at optical communication wavelengths, ranging from resonance-like to wide band pass filters with high transmission. The narrowest filter realized has a resonance-like transmission peak with a full width at half maximum of 3.4 nm. These devices could be attractive for coarse wavelength selection (pass and drop) and for sensing applications. 2013 Copyright 2013 Author(s). This article is distributed under a Creative Commons Attribution 3.0 Unported License.

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

    CERN Document Server

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


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

  11. Generation of an entangled traveling photon-phonon pair in an optomechanical resonator-waveguide system (United States)

    Yang, Zhenshan; Zhang, Xia; Wang, Minghong; Bai, Chenglin


    We show that an entangled traveling photon-phonon pair can be generated in a resonator-waveguide structure via optomechanical interaction. We employ the "backward Heisenberg picture" approach to write an analytic expression for the output quantum state, from which the generation efficiency and the entanglement of the photon-phonon pair are calculated. We find that the photon-phonon entanglement can be manipulated by adjusting the spectral width of the input pulse.

  12. Reconfigurable Coplanar Waveguide (CPW and Half-Mode Substrate Integrated Waveguide (HMSIW Band-Stop Filters Using a Varactor-Loaded Metamaterial-Inspired Open Resonator

    Directory of Open Access Journals (Sweden)

    Juan Hinojosa


    Full Text Available An open ring resonator (ORR loaded with a varactor diode is designed and implemented in order to achieve high-performance tunable band-stop filters in planar technology with a compact size. This varactor-loaded ORR (VLORR is versatile. It allows a shunt connection with different planar waveguide sections. In this paper, it has been connected to a coplanar waveguide (CPW and a half-mode substrate integrated waveguide (HMSIW. As a reverse bias voltage is applied to the VLORR, a continuous tuning over the resulting stop-band can be achieved. To illustrate the possibilities of the VLORR, three prototypes have been designed, fabricated, and characterized. The three prototypes show an outstanding performance, with a rejection level at the resonant frequency and a tuning range greater than 12 dB and 85%, respectively. This VLORR has high potential value in microwave communication systems to eliminate unwanted signals.

  13. Reconfigurable Coplanar Waveguide (CPW) and Half-Mode Substrate Integrated Waveguide (HMSIW) Band-Stop Filters Using a Varactor-Loaded Metamaterial-Inspired Open Resonator. (United States)

    Hinojosa, Juan; Saura-Ródenas, Adrián; Alvarez-Melcon, Alejandro; Martínez-Viviente, Félix L


    An open ring resonator (ORR) loaded with a varactor diode is designed and implemented in order to achieve high-performance tunable band-stop filters in planar technology with a compact size. This varactor-loaded ORR (VLORR) is versatile. It allows a shunt connection with different planar waveguide sections. In this paper, it has been connected to a coplanar waveguide (CPW) and a half-mode substrate integrated waveguide (HMSIW). As a reverse bias voltage is applied to the VLORR, a continuous tuning over the resulting stop-band can be achieved. To illustrate the possibilities of the VLORR, three prototypes have been designed, fabricated, and characterized. The three prototypes show an outstanding performance, with a rejection level at the resonant frequency and a tuning range greater than 12 dB and 85%, respectively. This VLORR has high potential value in microwave communication systems to eliminate unwanted signals.

  14. Plasmonic Waveguide Coupled Ring Cavity for a Non-Resonant Type Refractive Index Sensor

    Directory of Open Access Journals (Sweden)

    Soon-Hong Kwon


    Full Text Available Sensitive refractive index sensors with small footprints have been studied to allow the integration of a large number of sensors into a tiny chip for bio/chemical applications. In particular, resonant-type index sensors based on various micro/nanocavities, which use a resonant wavelength dependence on the refractive index of the analyte, have been developed. However, the spectral linewidth of the resonance, which becomes the resolution limit, is considerably large in plasmonic cavities due to the large absorption loss of metals. Therefore, there is demand for a new type of plasmonic refractive index sensor that is not limited by the linewidth of the cavity. We propose a new type of plasmonic index sensors consisting of a channel waveguide and a ring cavity. Two emissions from the ring cavity in both directions of the waveguide couple with a reflection phase difference depending on the length of a closed right arm with a reflecting boundary. Therefore, the output power dramatically and sensitively changes as a function of the refractive index of the analyte filling the waveguide.

  15. High Quality Factor Graphene-Based Two-Dimensional Heterostructure Mechanical Resonator. (United States)

    Will, M; Hamer, M; Müller, M; Noury, A; Weber, P; Bachtold, A; Gorbachev, R V; Stampfer, C; Güttinger, J


    Ultralight mechanical resonators based on low-dimensional materials are well suited as exceptional transducers of minuscule forces or mass changes. However, the low dimensionality also provides a challenge to minimize resistive losses and heating. Here, we report on a novel approach that aims to combine different two-dimensional (2D) materials to tackle this challenge. We fabricated a heterostructure mechanical resonator consisting of few layers of niobium diselenide (NbSe2) encapsulated by two graphene sheets. The hybrid membrane shows high quality factors up to 245,000 at low temperatures, comparable to the best few-layer graphene mechanical resonators. In contrast to few-layer graphene resonators, the device shows reduced electrical losses attributed to the lower resistivity of the NbSe2 layer. The peculiar low-temperature dependence of the intrinsic quality factor points to dissipation over two-level systems which in turn relax over the electronic system. Our high sensitivity readout is enabled by coupling the membrane to a superconducting cavity which allows for the integration of the hybrid mechanical resonator as a sensitive and low loss transducer in future quantum circuits.

  16. Silicon Oxynitride Optical Waveguide Ring Resonator Utilizing a Two-Mode Interferometer Structure

    Directory of Open Access Journals (Sweden)

    Kaixin Chen


    Full Text Available Silicon oxynitride (SiOxNy, SiON optical waveguide ring resonator, in which a two-mode interferometer is used to replace the directional coupler in a conventional ring resonator, has been designed and fabricated. Preliminary results exhibit the same of free spectral range of 100 GHz but different quality factors of 3700 and 3900 at 1550 nm for transverse electric (TE and transverse magnetic (TM mode, respectively. The extinction ratio is more than 18 dB over the entire C-band, and the insertion loss is lower than 9.5 dB for TE and TM mode.

  17. Resonant waveguide grating imagers for single cell analysis and high throughput screening (United States)

    Fang, Ye


    Resonant waveguide grating (RWG) systems illuminate an array of diffractive nanograting waveguide structures in microtiter plate to establish evanescent wave for measuring tiny changes in local refractive index arising from the dynamic mass redistribution of living cells upon stimulation. Whole-plate RWG imager enables high-throughput profiling and screening of drugs. Microfluidics RWG imager not only manifests distinct receptor signaling waves, but also differentiates long-acting agonism and antagonism. Spatially resolved RWG imager allows for single cell analysis including receptor signaling heterogeneity and the invasion of cancer cells in a spheroidal structure through 3-dimensional extracellular matrix. High frequency RWG imager permits real-time detection of drug-induced cardiotoxicity. The wide coverage in target, pathway, assay, and cell phenotype has made RWG systems powerful tool in both basic research and early drug discovery process.

  18. Thermionic cooling devices based on resonant-tunneling AlGaAs/GaAs heterostructure (United States)

    Bescond, M.; Logoteta, D.; Michelini, F.; Cavassilas, N.; Yan, T.; Yangui, A.; Lannoo, M.; Hirakawa, K.


    We study by means of full quantum simulations the operating principle and performance of a semiconductor heterostructure refrigerator combining resonant tunneling filtering and thermionic emission. Our model takes into account the coupling between the electric and thermal currents by self-consistently solving the transport equations within the non-equilibrium Green’s function framework and the heat equation. We show that the device can achieve relatively high cooling power values, while in the considered implementation, the maximum lattice temperature drop is severely limited by the thermal conductivity of the constituting materials. In such an out-of-equilibrium structure, we then emphasize the significant deviation of the phonon temperature from its electronic counterpart which can vary over several hundred Kelvin. The interplay between those two temperatures and the impact on the electrochemical potential is also discussed. Finally, viable options toward an optimization of the device are proposed.

  19. Temperature dependence of electric field tunable ferromagnetic resonance lineshape in multiferroic heterostructure

    Directory of Open Access Journals (Sweden)

    Fenglong Wang


    Full Text Available Herein, we experimentally investigate the effect of temperature on the electric field tunable ferromagnetic resonance (FMR in a ferroelectric/ferromagnetic heterostructure, and demonstrate the tuning of abnormal change in FMR using the polarization of the ferroelectric layer above 200 K. The FMR was found to be almost unchanged under different electric field strength at 100 K owing to frozen polarization, which causes extremely weak magnetoelectric coupling. More interestingly, negative effective linewidth was observed when an electric field greater than 10 kV/cm was applied above 220 K. The simultaneous electrical control of magnetization and its damping via FMR based on linear magnetoelectric coupling are directly relevant to use of composite multiferroics for a wide range of devices.

  20. Highly-efficient fully resonant vertical couplers for InP active-passive monolithic integration using vertically phase matched waveguides. (United States)

    López, Oscar García; Lasaosa, Daniel; López-Amo, Manuel; Galarza, Marko


    A new active-passive monolithic integration approach for photonic components based on vertical evanescent coupling is presented. Two vertically stacked waveguides are used in order to provide full resonant power transfer between them and avoiding the need of tapered structures. Light confinement in each waveguide is achieved combining strong lateral asymmetric structures and bent waveguides, both defined during lithography. Low propagation losses for the active waveguide and coupling efficiencies to the passive section as high as 97% have been obtained.

  1. Magneto-optical plasmonic heterostructure with ultranarrow resonance for sensing applications (United States)

    Ignatyeva, Daria O.; Knyazev, Grigory A.; Kapralov, Pavel O.; Dietler, Giovanni; Sekatskii, Sergey K.; Belotelov, Vladimir I.


    Currently, sensors invade into our everyday life to bring higher life standards, excellent medical diagnostic and efficient security. Plasmonic biosensors demonstrate an outstanding performance ranking themselves among best candidates for different applications. However, their sensitivity is still limited that prevents further expansion. Here we present a novel concept of magnetoplasmonic sensor with ultranarrow resonances and high sensitivity. Our approach is based on the combination of a specially designed one-dimensional photonic crystal and a ferromagnetic layer to realize ultralong-range propagating magnetoplasmons and to detect alteration of the environment refractive index via observation of the modifications in the Transversal Magnetooptical Kerr Effect spectrum. The fabrication of such a structure is relatively easy in comparison with e.g. nanopatterned samples. The fabricated heterostructure shows extremely sharp (angular width of 0.06°) surface plasmon resonance and even sharper magnetoplasmonic resonance (angular width is 0.02°). It corresponds to the propagation length as large as 106 μm which is record for magnetoplasmons and promising for magneto-optical interferometry and plasmonic circuitry as well as magnetic field sensing. The magnitude of the Kerr effect of 11% is achieved which allows for detection limit of 1•10-6. The prospects of further increase of the sensitivity of this approach are discussed.

  2. Reusable EGaIn-Injected Substrate-Integrated-Waveguide Resonator for Wireless Sensor Applications. (United States)

    Memon, Muhammad Usman; Lim, Sungjoon


    The proposed structure in this research is constructed on substrate integrated waveguide (SIW) technology and has a mechanism that produces 16 different and distinct resonant frequencies between 2.45 and 3.05 GHz by perturbing a fundamental TE10 mode. It is a unique method for producing multiple resonances in a radio frequency planar structure without any extra circuitry or passive elements is developed. The proposed SIW structure has four vertical fluidic holes (channels); injecting eutectic gallium indium (EGaIn), also known commonly as liquid metal (LM), into these vertical channels produces different resonant frequencies. Either a channel is empty, or it is filled with LM. In total, the combination of different frequencies produced from four vertical channels is 16.

  3. Coupled mode theory of microtoroidal resonators with a one-dimensional waveguide (United States)

    Nguyen, Thi Phuc Tan; Krivitsky, Leonid; Kwek, Leong Chuan


    We study the transmission of light through a system consisting of an arbitrary number N of microtoroidal resonators coupled to a one-dimensional (1D) waveguide. The transmission T through such a system and its full-width at half-maximum (FWHM) are calculated for various values of N and mutual-mode coupling coefficients. We found that at small mutual-mode coupling, the minimum transmission vanishes exponentially with N while the FWHM is proportional to √{ N }. At big mutual-mode coupling, as the number of resonators increases, the mode-splitting is reduced. Our findings contribute to better understanding of novel interfaces between quantum emitters and resonant photonic structures for quantum information processing.

  4. Analysis of coupled resonator optical waveguide gyroscope based on periodically modulated coupling and circumferences (United States)

    Huang, Jie; Zhang, Hailiang; Yang, Junbo; Zhang, Jingjing; Wu, Wenjun; Chang, Shengli


    Based on periodically modulated coupling and circumferences, we developed a new structure for coupled resonator optical waveguide (CROW) gyroscopes. Its sensitivity and resolution were significantly improved. With our new structure, which overcomes the individual limitations of the previous schemes, the sensitivity and resolution of our gyroscope are higher than those with coupling-coefficient modulation alone and circumference modulation alone. The resolution of the gyroscope gradually declines with increasing resonator propagation loss; when the quality factor Q ≤ 2 ×106 , the height of the center resonance peak of the transmission band decreases by more than 90%. Fortunately, this effect can be weakened by increasing the circumference difference. We also numerically analyzed the influence of manufacturing errors on the performance of the gyroscope. We found that the fluctuations of radius have a greater influence than the fluctuations of quality factor.

  5. Nanoscale temperature sensor based on Fano resonance in metal-insulator-metal waveguide (United States)

    Kong, Yan; Wei, Qi; Liu, Cheng; Wang, Shouyu


    In order to realize temperature measurements with high sensitivity using compact structure, a nanoscale metal-insulator-metal waveguide based sensor combining with Fano resonance is proposed in this paper. Sealed ethanol in resonant cavity is adopted to further improve sensing performance. Additionally, dual resonant cavity based configuration is designed to generate a Fano-based sharp and asymmetric spectrum, providing high figure of merit in measurements. Moreover, structural parameters are optimized considering both transmission rate and spectral peak width. Certified by numerical calculation, sensitivity of 0.36 nm/°C is acquired with the optimized structure, indicating the designed sensor can play an important role in the nano-integrated plasmonic devices for high-accurate temperature detection.

  6. A portable optical waveguide resonance light-scattering scanner for microarray detection. (United States)

    Xing, Xuefeng; Liu, Wanyao; Li, Tao; Xing, Shu; Fu, Xueqi; Wu, Dongyang; Liu, Dianjun; Wang, Zhenxin


    In the present work, a portable and low-cost planar waveguide based resonance light scattering (RLS) scanner (termed as: PW-RLS scanner) has been developed for microarray detection. The PW-RLS scanner employs a 2 × 4 white light emitting diode array (WLEDA) as the excitation light source, a folded optical path with a complementary metal oxide semiconductor (CMOS) as the signal/image acquisition device and stepper motors with gear drives as the mechanical drive system. The biological binding/recognizing events on the microarray can be detected with an evanescent waveguide-directed illumination and light-scattering label (e.g., nanoparticles) while the microarray slide acts as an evanescent waveguide substrate. The performance of the as-developed PW-RLS scanner has been evaluated by analyzing type 2 diabetes mellitus (T2DM) risk genes. Highly selective and sensitive (less than 1% allele frequency at the attomole-level) T2DM risk gene detection is achieved using single-stranded DNA functionalized gold nanoparticles (ssDNA-GNPs) as detection probes. Additionally, the successful simultaneous analysis of 15 T2DM patient genotypes suggests that the device has great potential for the realization of a personalized diagnostic test for a given disease or patient follow-up.

  7. Slot resonator-based electromagnetic bandgap coplanar waveguide and its filter application

    Energy Technology Data Exchange (ETDEWEB)

    Liu Haiwen [Microelectronic CAD Center, Hangzhou Dianzi University, Hangzhou 310018 (China)]. E-mail:; Sun Lingling [Microelectronic CAD Center, Hangzhou Dianzi University, Hangzhou 310018 (China); Yoshimasu, Toshihiko [Graduate School of Information, Production, and Systems, Waseda University, Kitakyushu 808-0135 (Japan)


    One-dimensional (1-D) slot resonator-based electromagnetic bandgap coplanar waveguide (SR-EBG-CPW) is proposed in this Letter. First, the SR-EBG-CPW unit cell is discussed and exhibits bandstop performance without any periodic structure. Then, its circuit model is extracted from the full-wave simulations and the frequency characteristics are explained by employing the equivalent circuit parameters and field analysis. Finally, a miniaturized bandstop filter with SR-EBG-CPW is presented and fabricated. Measurement shows that the designed filter provides good bandstop and slow-wave performances as predicted and has potential applications to compact microwave designs.

  8. Ultrasensitive Terahertz Biosensors Based on Fano Resonance of a Graphene/Waveguide Hybrid Structure

    Directory of Open Access Journals (Sweden)

    Banxian Ruan


    Full Text Available Graphene terahertz (THz surface plasmons provide hope for developing functional devices in the THz frequency. By coupling graphene surface plasmon polaritons (SPPs and a planar waveguide (PWG mode, Fano resonances are demonstrated to realize an ultrasensitive terahertz biosensor. By analyzing the dispersion relation of graphene SPPs and PWG, the tunable Fano resonances in the terahertz frequency are discussed. It is found that the asymmetric lineshape of Fano resonances can be manipulated by changing the Fermi level of graphene, and the influence of the thickness of coupling layer and air layer in sandwich structure on the Fano resonances is also discussed in detail. We then apply the proposed Fano resonance to realize the ultrasensitive terahertz biosensors, it is shown that the highest sensitivities of 3260 RIU−1 are realized. Our result is two orders of a conventional surface plasmon resonance sensor. Furthermore, we find that when sensing medium is in the vicinity of water in THz, the sensitivity increases with increasing refractive index of the sensing medium.

  9. Theoretical modeling of a coupled plasmon waveguide resonance sensor based on multimode optical fiber (United States)

    Liu, Kun; Xue, Meng; Jiang, Junfeng; Wang, Tao; Chang, Pengxiang; Liu, Tiegen


    A coupled plasmon waveguide resonance (CPWR) sensor based on metal/dielectric-coated step index multimode optical fiber is proposed. Theoretical simulations using the four-layer Fresnel equations based on a bi-dimensional optical fiber model were implemented on four structures: Ag-ZnO, Au-ZnO, Ag-TiO2 and Au-TiO2. By controlling the thickness of dielectric layer, we managed to manipulate the CPWR resonance wavelengths. When a CPWR resonance dip is in the short wavelength region, it is insensitive to the change of surrounding refractive index (SRI) and can be used as a reference to improve the sensing accuracy of surface plasmon resonance (SPR) mode. With the increase of the thickness of the dielectric layer, the CPWR resonance dips shift to longer wavelength and the corresponding sensitivities increase. When the 1st CPWR resonance wavelength is near 1550 nm and SRI is around 1.333, the sensitivities of four structures reach 1360.61 nm/RIU, 1375.76 nm/RIU, 1048.48 nm/RIU and 1015.15 nm/RIU, respectively. The values are close to that of the conventional SPR optical fiber sensor while the spectral bandwidths of the optical fiber CPWR sensors are narrower.

  10. Controllable coupling between a nanomechanical resonator and a coplanar-waveguide resonator via a superconducting flux qubit (United States)

    Xiong, Wei; Jin, Da-Yu; Jing, Jun; Lam, Chi-Hang; You, J. Q.


    We study a tripartite quantum system consisting of a coplanar-waveguide (CPW) resonator and a nanomechanical resonator (NAMR) connected by a flux qubit, where the flux qubit has a large detuning from both resonators. By a unitary transformation and a second-order approximation, we obtain a strong and controllable (i.e., magnetic-field-dependent) effective coupling between the NAMR and the CPW resonator. Due to the strong coupling, vacuum Rabi splitting can be observed from the voltage-fluctuation spectrum of the CPW resonator. We further study the properties of single-photon transport as inferred from the reflectance or equivalently the transmittance. We show that the reflectance and the corresponding phase-shift spectra both exhibit doublet of narrow spectral features due to vacuum Rabi splitting. By tuning the external magnetic field, the reflectance and the phase shift can be varied from 0 to 1 and -π to π , respectively. The results indicate that this hybrid quantum system can act as a quantum router.

  11. Characterization of low loss microstrip resonators as a building block for circuit QED in a 3D waveguide (United States)

    Zoepfl, D.; Muppalla, P. R.; Schneider, C. M. F.; Kasemann, S.; Partel, S.; Kirchmair, G.


    Here we present the microwave characterization of microstrip resonators, made from aluminum and niobium, inside a 3D microwave waveguide. In the low temperature, low power limit internal quality factors of up to one million were reached. We found a good agreement to models predicting conductive losses and losses to two level systems for increasing temperature. The setup presented here is appealing for testing materials and structures, as it is free of wire bonds and offers a well controlled microwave environment. In combination with transmon qubits, these resonators serve as a building block for a novel circuit QED architecture inside a rectangular waveguide.

  12. Vertical optical ring resonators fully integrated with nanophotonic waveguides on silicon-on-insulator substrates. (United States)

    Madani, Abbas; Kleinert, Moritz; Stolarek, David; Zimmermann, Lars; Ma, Libo; Schmidt, Oliver G


    We demonstrate full integration of vertical optical ring resonators with silicon nanophotonic waveguides on silicon-on-insulator substrates to accomplish a significant step toward 3D photonic integration. The on-chip integration is realized by rolling up 2D differentially strained TiO(2) nanomembranes into 3D microtube cavities on a nanophotonic microchip. The integration configuration allows for out-of-plane optical coupling between the in-plane nanowaveguides and the vertical microtube cavities as a compact and mechanically stable optical unit, which could enable refined vertical light transfer in 3D stacks of multiple photonic layers. In this vertical transmission scheme, resonant filtering of optical signals at telecommunication wavelengths is demonstrated based on subwavelength thick-walled microcavities. Moreover, an array of microtube cavities is prepared, and each microtube cavity is integrated with multiple waveguides, which opens up interesting perspectives toward parallel and multi-routing through a single-cavity device as well as high-throughput optofluidic sensing schemes.

  13. Hybrid Quantum Device Based on N V Centers in Diamond Nanomechanical Resonators Plus Superconducting Waveguide Cavities (United States)

    Li, Peng-Bo; Liu, Yong-Chun; Gao, S.-Y.; Xiang, Ze-Liang; Rabl, Peter; Xiao, Yun-Feng; Li, Fu-Li


    We propose and analyze a hybrid device by integrating a microscale diamond beam with a single built-in nitrogen-vacancy (N V ) center spin to a superconducting coplanar waveguide (CPW) cavity. We find that under an ac electric field the quantized motion of the diamond beam can strongly couple to the single cavity photons via a dielectric interaction. Together with the strong spin-motion interaction via a large magnetic-field gradient, it provides a hybrid quantum device where the diamond resonator can strongly couple both to the single microwave-cavity photons and to the single N V center spin. This enables coherent information transfer and effective coupling between the N V spin and the CPW cavity via mechanically dark polaritons. This hybrid spin-electromechanical device, with tunable couplings by external fields, offers a realistic platform for implementing quantum information with single N V spins, diamond mechanical resonators, and single microwave photons.

  14. Novel aspect in grain size control of nanocrystalline diamond film for thin film waveguide mode resonance sensor application. (United States)

    Lee, Hak-Joo; Lee, Kyeong-Seok; Cho, Jung-Min; Lee, Taek-Sung; Kim, Inho; Jeong, Doo Seok; Lee, Wook-Seong


    Nanocrystalline diamond (NCD) thin film growth was systematically investigated for application for the thin film waveguide mode resonance sensor. The NCD thin film was grown on the Si wafer or on the SiO2-coated sapphire substrate using the hot filament chemical vapor deposition (HFCVD). The structural/optical properties of the samples were characterized by the high-resolution scanning electron microscopy (HRSEM), high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray spectroscopy (EDS), near edge X-ray absorption fine structure (NEXAFS), X-ray diffraction (XRD), and ultraviolet-visible (UV-vis) spectroscopy. The waveguide modes of the NCD layer were studied by prism coupler technique using laser (wavelength: 632.8 nm) with varying incident angle. A novel aspect was disclosed in the grain size dependence on the growth temperature at the relatively low methane concentration in the precursor gas, which was important for optical property: the grain size increased with decreasing growth temperature, which was contrary to the conventional knowledge prevailing in the microcrystalline diamond (MCD) domain. We have provided discussions to reconcile such observation. An optical waveguide mode resonance was demonstrated in the visible region using the microstructure-controlled transparent NCD thin film waveguide, which provided a strong potential for the waveguide mode resonance sensor applications.

  15. Low-loss high-confinement waveguides and microring resonators in AlGaAs-on-insulator

    DEFF Research Database (Denmark)

    Ottaviano, Luisa; Pu, Minhao; Semenova, Elizaveta


    microring resonators. Here, we report a process tomake high-quality AlGaAs-on-insulator (AlGaAsOI) waferswhere high confinement waveguides can be realized. Using optimized patterning processes, we fabricated AlGaAsOI waveguides with propagation losses as low as 1 dB/cmand microring resonators with quality......AlGaAs is a promising material for integrated nonlinearphotonics due to its intrinsic high nonlinearity. However,the challenging fabrication of deep etched AlGaAs devices makes it difficult to realize high-performance devices such as low-loss dispersion engineered waveguides and high quality...... factors up to 350,000 at telecom wavelengths. Our demonstration opens new prospects for AlGaAs devices in integrated nonlinear photonics....

  16. Resonant magneto-tunnelling in GaAs/AlGaAs double-barrier heterostructures

    CERN Document Server

    Reker, T


    bottleneck for tunnelling of electrons and how this could account for the observed enhancement of the pseudogap around filling factor v = 1. Resonant magneto-tunnelling in GaAs/AlGaAs double-barrier heterostructures is studied at low temperatures. Magnetic fields aligned parallel to the barriers are used to map out the in-plane dispersion of the GAMMA-conduction band in GaAs/AlGaAs quantum wells. By rotating the magnetic field direction in the plane of the quantum well, it is demonstrated that the effective mass of confined GAMMA-conduction band electrons becomes anisotropic along the two orthogonal in-plane directions when an electric field is applied perpendicular to the interfaces. On a qualitative level, the anisotropy can be understood by the orthogonal orientations of bond-planes at opposite interfaces of the quantum well, whereby the symmetry is broken either by an electric field along [001] or by differences in interface roughness. On the quantitative level, a quantum mechanical model involving inte...

  17. Electron-spin-resonance transistors for quantum computing in silicon-germanium heterostructures (United States)

    Vrijen, Rutger; Yablonovitch, Eli; Wang, Kang; Jiang, Hong Wen; Balandin, Alex; Roychowdhury, Vwani; Mor, Tal; Divincenzo, David


    We apply the full power of modern electronic band-structure engineering and epitaxial heterostructures to design a transistor that can sense and control a single-donor electron spin. Spin-resonance transistors may form the technological basis for quantum information processing. One- and two-qubit operations are performed by applying a gate bias. The bias electric field pulls the electron wave function away from the dopant ion into layers of different alloy composition. Owing to the variation of the g factor (Si:g=1.998,Ge:g=1.563), this displacement changes the spin Zeeman energy, allowing single-qubit operations. By displacing the electron even further, the overlap with neighboring qubits is affected, which allows two-qubit operations. Certain silicon-germanium alloys allow a qubit spacing as large as 200 nm, which is well within the capabilities of current lithographic techniques. We discuss manufacturing limitations and issues regarding scaling up to a large size computer.

  18. A Coplanar Waveguide Resonator Based In-Line Material Characterization Sensor for Bulk and Metallized Dielectrics (United States)

    Talai, Armin; Gold, Gerald; Frank, Martin; Mann, Sebastian; Weigel, Robert; Koelpin, Alexander


    Microwave Materials such as Rogers RO3003 are subject to process-related fluctuations in terms of the relative permittivity and dielectric loss. The behavior of high frequency circuits like patch-antenna arrays and their distribution networks is dependent on the effective wavelength. Therefore, fluctuations of the complex permittivity will influence the resonance frequency and beam direction of the antennas. This paper presents a grounded coplanar waveguide based sensor, which can measure the complex permittivity at 77 GHz, as well as at other resonance frequencies, by applying it on top of the manufactured depaneling. The relative permittivity of the material under test (MUT) is a function of the resonance frequency shift and the dielectric loss of the MUT can be determined by transmission amplitude variations at the resonances. In addition, the sensor is robust against floating ground metallizations on inner printed circuit board layers, which are typically distributed over the entire surface below antennas. Furthermore, the impact from conductor surface roughness on the measured permittivity values is determined using the Gradient Model.

  19. Compact, lower-power-consumption wavelength tunable laser fabricated with silicon photonic-wire waveguide micro-ring resonators. (United States)

    Chu, Tao; Fujioka, Nobuhide; Ishizaka, Masashige


    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.

  20. Plasmon-Waveguide Resonances with Enhanced Figure of Merit and Their Potential for Anisotropic Biosensing in the Near Infrared Region


    Said Mahajna; Michal Neumann; Ofer Eyal; Atef Shalabney


    The TM and TE guided modes in the coupled plasmon-waveguide resonance configuration are investigated in the spectral domain. Here we use the modes dispersion to study their capability for sensing in the near infrared region. It is shown that the spectral widths of the guided modes are, at least, one order of magnitude smaller than the conventional surface plasmon resonance counterpart. The enhanced sensitivity and figure of merit of the guided modes reveal their potential for sensing in the s...

  1. Hafnium dioxide as a dielectric for highly-sensitive waveguide-coupled surface plasmon resonance sensors

    Directory of Open Access Journals (Sweden)

    Kunal Tiwari


    Full Text Available Hafnium dioxide has been recognized as an excellent dielectric for microelectronics. However, its usefulness for the surface plasmon based sensors has not yet been tested. Here we investigate its usefulness for waveguide-coupled bi-metallic surface plasmon resonance sensors. Several Ag/HfO2/Au multilayer structure sensors were fabricated and evaluated by optical measurements and computer simulations. The resulting data establish correlations between the growth parameters and sensor performance. The sensor sensitivity to refractive index of analytes is determined to be S n = ∂ θ SPR ∂ n ≥ 4 7 0 . The sensitivity data are supported by simulations, which also predict 314 nm for the evanescent field decay length in air.

  2. A saccharides sensor developed by symmetrical optical waveguide-based surface plasmon resonance

    Directory of Open Access Journals (Sweden)

    Ang Li


    Full Text Available We proposed a new saccharides sensor developed by symmetrical optical waveguide (SOW-based surface plasmon resonance (SPR. This unique MgF2/Au/MgF2/Analyte film structure results in longer surface plasmon wave (SPW propagation lengths and depths, leading to an increment of resolution. In this paper, we managed to decorate the dielectric interface (MgF2 layer by depositing a thin polydopamine film as surface-adherent that provides a platform for secondary reactions with the probe molecule. 3-Aminophenylboronic acid (3-PBA is chosen to be the saccharides sense probe molecule in the present work. The aqueous humor of Diabetes and Cataract patient whose blood glucose level is normal are analyzed and the results demonstrated that this sensor shows great potential in monitoring the blood sugar and can be adapted in the field of biological monitoring in the future.

  3. Self-referenced directional enhanced Raman scattering using plasmon waveguide resonance for surface and bulk sensing (United States)

    Wan, Xiu-mei; Gao, Ran; Lu, Dan-feng; Qi, Zhi-mei


    Surface plasmon-coupled emission has been widely used in fluorescence imaging, biochemical sensing, and enhanced Raman spectroscopy. A self-referenced directional enhanced Raman scattering for simultaneous detection of surface and bulk effects by using plasmon waveguide resonance (PWR) based surface plasmon-coupled emission has been proposed and experimentally demonstrated. Raman scattering was captured on the prism side in Kretschmann-surface plasmon-coupled emission. The distinct penetration depths (δ) of the evanescent field for the transverse electric (TE) and transverse magnetic (TM) modes result in different detected distances of the Raman signal. The experimental results demonstrate that the self-referenced directional enhanced Raman scattering of the TE and TM modes based on the PWR can detect and distinguish the surface and bulk effects simultaneously, which appears to have potential applications in researches of chemistry, medicine, and biology.

  4. Analytical approach for modeling and performance analysis of microring resonators as optical filters with multiple output bus waveguides (United States)

    Lakra, Suchita; Mandal, Sanjoy


    A quadruple micro-optical ring resonator (QMORR) with multiple output bus waveguides is mathematically modeled and analyzed by making use of the delay-line signal processing approach in Z-domain and Mason's gain formula. The performances of QMORR with two output bus waveguides with vertical coupling are analyzed. This proposed structure is capable of providing wider free spectral response from both the output buses with appreciable cross talk. Thus, this configuration could provide increased capacity to insert a large number of communication channels. The simulated frequency response characteristic and its dispersion and group delay characteristics are graphically presented using the MATLAB environment.

  5. Characterization of the dominant loss mechanisms in superconducting coplanar waveguide resonators (United States)

    Calusine, Greg; Melville, Alexander; Woods, Wayne; Kim, David K.; Miloshi, Xhovalin; Sevi, Arjan; Yoder, Jonilyn; Oliver, William D.

    The characterization of losses in superconducting coplanar waveguide (CPW) resonators is commonly used as a surrogate means to probe relaxation in superconducting qubit capacitor structures. However, this method is complicated by device-to-device variations that result from a sensitivity to variations in fabrication processes, packaging, and measurement methods. We present results on characterizing ensembles of aluminum, niobium, and titanium nitride superconducting CPW resonators to determine the statistical significance of the effects of fabrication process changes on resonator intrinsic quality factor. Furthermore, we report progress on experiments aimed at determining the impact of other competing loss mechanisms such as vortex trapping, package coupling, and substrate loss. These results are then applied to the study of relaxation in superconducting qubits and investigations into the microscopic origins of surface losses. This research was funded in part by the Intelligence Advanced Research Projects Activity (IARPA). The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of IARPA or the US Government.

  6. Real time hybridization studies by resonant waveguide gratings using nanopattern imaging for Single Nucleotide Polymorphism detection

    KAUST Repository

    Bougot-Robin, Kristelle


    2D imaging of biochips is particularly interesting for multiplex biosensing. Resonant properties allow label-free detection using the change of refractive index at the chip surface. We demonstrate a new principle of Scanning Of Resonance on Chip by Imaging (SORCI) based on spatial profiles of nanopatterns of resonant waveguide gratings (RWGs) and its embodiment in a fluidic chip for real-time biological studies. This scheme allows multiplexing of the resonance itself by providing nanopattern sensing areas in a bioarray format. Through several chip designs we discuss resonance spatial profiles, dispersion and electric field distribution for optimal light-matter interaction with biological species of different sizes. Fluidic integration is carried out with a black anodized aluminum chamber, advantageous in term of mechanical stability, multiple uses of the chip, temperature control and low optical background. Real-time hybridization experiments are illustrated by SNP (Single Nucleotide Polymorphism) detection in gyrase A of E. coli K12, observed in evolution studies of resistance to the antibiotic ciprofloxacin. We choose a 100 base pairs (bp) DNA target (∼30 kDa) including the codon of interest and demonstrate the high specificity of our technique for probes and targets with close affinity constants. This work validates the safe applicability of our unique combination of RWGs and simple instrumentation for real-time biosensing with sensitivity in buffer solution of ∼10 pg/mm2. Paralleling the success of RWGs sensing for cells sensing, our work opens new avenues for a large number of biological studies. © 2013 Springer Science+Business Media.

  7. Plasmon-Waveguide Resonances with Enhanced Figure of Merit and Their Potential for Anisotropic Biosensing in the Near Infrared Region

    Directory of Open Access Journals (Sweden)

    Said Mahajna


    Full Text Available The TM and TE guided modes in the coupled plasmon-waveguide resonance configuration are investigated in the spectral domain. Here we use the modes dispersion to study their capability for sensing in the near infrared region. It is shown that the spectral widths of the guided modes are, at least, one order of magnitude smaller than the conventional surface plasmon resonance counterpart. The enhanced sensitivity and figure of merit of the guided modes reveal their potential for sensing in the spectral interrogation method where the traditional configurations are inherently limited. Moreover, the high resolution associated with the narrow resonances and the polarization dependence make these modes very promising for anisotropic biosensing in the spectral interrogation approach. The extremely high figure of merit, large penetration depth, and propagation distance in the near infrared region open the possibility of combining the plasmon-waveguide configuration with absorption spectroscopy techniques for molecular recognition.

  8. Investigation on thermal behavior of resonant waveguide-grating mirrors in an Yb:YAG thin-disk laser (United States)

    Rumpel, Martin; Dannecker, Benjamin; Voss, Andreas; Möller, Michael; Moormann, Christian; Graf, Thomas; Abdou Ahmed, Marwan


    We present the experimental investigations of different designs of resonant waveguide-grating mirrors (RWG) which are used as intracavity folding mirror in an Yb:YAG thin-disk laser. The studied mirrors combine structured fused silica substrates, a thin-layer waveguide (Ta2O5), a buffer layer (SiO2) and partial reflectors. The grating period was chosen to be 510 nm to allow resonances at an angle of incidence of ~10° for TE polarization. The waveguide layer has a thickness of 236 nm. It is followed by the buffer layer with a thickness of 580 nm and the subsequent alternating Ta2O5/SiO2 layers. The exact coating sequence depends on the two design approaches which were investigated in this work: either introducing different partial reflectors, i.e. stacks of quarter-wave layers on top of the waveguide while keeping the groove depth of the grating constant, or increasing the grating depth, while keeping an identical partial reflector. The investigation was focused on the rise of the surface temperature due to the coupling of the incident radiation to a waveguide mode, as well as on the laser efficiency, polarization and wavelength selectivity. It is found that, when compared to the simplest RWG design which consists of only a single Ta2O5 waveguide layer, damage threshold as well as laser efficiency can be significantly increased, while the laser performances in terms of polarization- and wavelength selectivity are maintained. So far, the presented RWG allow the generation of linear polarization with a narrow spectral linewidth down to 25 pm FWHM in a fundamental mode Yb:YAG thin-disk laser. Damage thresholds of 60kW/cm2 have been reached where only 63K of surface temperature increase was observed. This shows that the improved mirrors are suitable for the generation of kW-class narrow linewidth, linearly polarized Yb:YAG thin-disk lasers.

  9. Coplanar waveguides loaded with a split ring resonator-based microwave sensor for aqueous sucrose solutions (United States)

    Harnsoongnoen, Supakorn; Wanthong, Anuwat


    In this study, a coplanar waveguide (CPW) loaded with a split ring resonator (SRR) based microwave sensor was developed for the detection of aqueous sucrose solutions. The fabrication and testing enabled the identification of the sucrose concentration. The CPW loaded with a SRR structure design was produced using electromagnetic models to improve its sensitivity by increasing the magnitude of transmission coefficient (S 21). The resonance behavior, based on S 21 characteristics of the microwave sensor, was analyzed in the range from 2-3 GHz with air and deionized water containing different sucrose concentrations in the range from 0-1 g ml-1. The experimental results showed that the proposed system has great potential to determine the sucrose concentration. It was shown that the proposed sensor has a high dynamic range and linearity for sucrose concentration sensing. The feature characteristic based on the CPW loaded with SRR sensing was excellent as defined by a T-circuit model as an inductor, capacitor, and resistor. It also provides an opportunity for the development of a low-cost sucrose meter system as an electronic tongue.

  10. Separating hyperfine from spin-orbit interactions in organic semiconductors by multi-octave magnetic resonance using coplanar waveguide microresonators (United States)

    Joshi, G.; Miller, R.; Ogden, L.; Kavand, M.; Jamali, S.; Ambal, K.; Venkatesh, S.; Schurig, D.; Malissa, H.; Lupton, J. M.; Boehme, C.


    Separating the influence of hyperfine from spin-orbit interactions in spin-dependent carrier recombination and dissociation processes necessitates magnetic resonance spectroscopy over a wide range of frequencies. We have designed compact and versatile coplanar waveguide resonators for continuous-wave electrically detected magnetic resonance and tested these on organic light-emitting diodes. By exploiting both the fundamental and higher-harmonic modes of the resonators, we cover almost five octaves in resonance frequency within a single setup. The measurements with a common π-conjugated polymer as the active material reveal small but non-negligible effects of spin-orbit interactions, which give rise to a broadening of the magnetic resonance spectrum with increasing frequency.

  11. Separating hyperfine from spin-orbit interactions in organic semiconductors by multi-octave magnetic resonance using coplanar waveguide microresonators

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, G.; Miller, R.; Ogden, L.; Kavand, M.; Jamali, S.; Ambal, K.; Malissa, H.; Boehme, C., E-mail: [Department of Physics and Astronomy, University of Utah, Salt Lake City, Utah 84112 (United States); Venkatesh, S.; Schurig, D. [Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, Utah 84112 (United States); Lupton, J. M. [Department of Physics and Astronomy, University of Utah, Salt Lake City, Utah 84112 (United States); Institut für Experimentelle und Angewandte Physik, Universität Regensburg, D-93040 Regensburg (Germany)


    Separating the influence of hyperfine from spin-orbit interactions in spin-dependent carrier recombination and dissociation processes necessitates magnetic resonance spectroscopy over a wide range of frequencies. We have designed compact and versatile coplanar waveguide resonators for continuous-wave electrically detected magnetic resonance and tested these on organic light-emitting diodes. By exploiting both the fundamental and higher-harmonic modes of the resonators, we cover almost five octaves in resonance frequency within a single setup. The measurements with a common π-conjugated polymer as the active material reveal small but non-negligible effects of spin-orbit interactions, which give rise to a broadening of the magnetic resonance spectrum with increasing frequency.

  12. Band Edge Energetics of Heterostructured Nanorods: Photoemission Spectroscopy and Waveguide Spectroelectrochemistry of Au-Tipped CdSe Nanorod Monolayers. (United States)

    Ehamparam, Ramanan; Pavlopoulos, Nicholas G; Liao, Michael W; Hill, Lawrence J; Armstrong, Neal R; Pyun, Jeffrey; Saavedra, S Scott


    Conduction and valence band energies (ECB, EVB) for CdSe nanorods (NRs) functionalized with Au nanoparticle (NP) tips are reported here, referenced to the vacuum scale. We use (a) UV photoemission spectroscopy (UPS) to measure EVB for NR films, utilizing advanced approaches to secondary electron background correction, satellite removal to enhance spectral contrast, and correction for shifts in local vacuum levels; and (b) waveguide-based spectroelectrochemistry to measure ECB from onset potentials for electron injection into NR films tethered to ITO. For untipped CdSe NRs, both approaches show EVB = 5.9-6.1 eV and ECB = 4.1-4.3 eV. Addition of Au tips alters the NR band edge energies and introduces midgap states, in ways that are predicted to influence the efficiency of these nanomaterials as photoelectrocatalysts. UPS results show that Au tipping shifts EVB closer to vacuum by up to 0.4 eV, shifts the apparent Fermi energy toward the middle of the band gap, and introduces additional states above EVB. Spectroelectrochemical results confirm these trends: Au tipping shifts ECB closer to vacuum, by 0.4-0.6 eV, and introduces midgap states below ECB, which are assigned as metal-semiconductor interface (MSI) states. Characterization of these band edge energies and understanding the origins of MSI states is needed to design energy conversion systems with proper band alignment between the light absorbing NR, the NP catalyst, and solution electron donors and acceptors. The complementary characterization protocols presented here should be applicable to a wide variety of thin films of heterogeneous photoactive nanomaterials, aiding in the identification of the most promising material combinations for photoelectrochemical energy conversion.

  13. Study on Fano resonance regulating mechanism of Si contained metal-dielectric-metal waveguide coupled rectangular cavity (United States)

    Chen, Ying; Luo, Pei; Zhao, Zhi-yong; He, Lei; Cui, Xing-ning


    Based on the transmission properties and the photon location characteristics of the Surface plasmon polaritons (SPPs) sub-wavelength structure, a metal-dielectric-metal (MDM) waveguide coupled rectangular cavity structure is proposed. Dielectric material silicon (Si) is introduced in the structure to overcome the high loss of the metal materials. Due to the large refractive index difference between silicon and air, the reflections of SPPs and the incident light at the two ends of the Si-air-Si cavity in the sub-wavelength structure are small meanwhile the transmissions are high, which leads to a wider continuous spectrum. And when the SPPs enter the rectangular cavity in the metal and the phase matching condition is satisfied, the resonance will occur and a narrow transmission spectrum peak will be generated. Through the coupling of the wider continuous state and the narrower isolated state, the Fano resonance will occur. According to the phase-matching condition of resonance, the relationship model between the effective refractive index of the waveguide and the wavelength shift of the resonant peak is established. And with the increase of the length L of the rectangular cavity, the red shift of the resonant peak will occur, which can improve the sensitivity of the sensing structure. The influences of structural parameters L, W and g on Fano resonance are analyzed respectively to optimize the structural parameters by the finite element methods. The Figure of merit (FOM) value can be adjusted and controlled with the change of the structural parameters L, W and g. The FOM value of the optimized structure parameters can attain to 1.19 ×104. The optimized structure parameters are adopted to discuss the sensing performances of the structure. The results show that the sensitivity of the sensor is about 1612 nm/RIU. The waveguide structure mentioned above can provide effective theoretical references for the miniaturization and high integration of photonic devices and

  14. Solution of cavity resonance and waveguide scattering problems using the eigenmode projection technique (United States)

    Nasr, Mamdouh H.; Othman, Mohamed A. K.; Eshrah, Islam A.; Abuelfadl, Tamer M.


    New developments in the eigenmode projection technique (EPT) are introduced in solving problems of electromagnetic resonance in closed cavities as well as scattering from discontinuities in guided-wave structures. The EPT invokes the eigenmodes of a canonical predefined cavity in the solution procedure and uses the expansion of these eigenmodes to solve Maxwell's equations, in conjunction with a convenient choice of port boundary conditions. For closed cavities, a new spurious-mode separation method is developed, showing robust and efficient spurious-mode separation. This has been tested using more complex and practical examples demonstrating the powerful use of the presented approach. For waveguide scattering problems, convergence studies are being performed showing stable solutions for a relatively small number of expansion modes, and the proposed method has advantages over conventional solvers in analyzing electromagnetic problems with inhomogeneous materials. These convergence studies also lead to an efficient rule-of-thumb for the number of modes to be used in the simulation. The ability to handle closed and open structures is presented in a unified framework that highlights the generality of the EPT which could be used to analyze and design a variety of microwave components.

  15. Intensity-based readout of resonant-waveguide grating biosensors: Systems and nanostructures (United States)

    Paulsen, Moritz; Jahns, Sabrina; Gerken, Martina


    Resonant waveguide gratings (RWG) - also called photonic crystal slabs (PCS) - have been established as reliable optical transducers for label-free biochemical assays as well as for cell-based assays. Current readout systems are based on mechanical scanning and spectrometric measurements with system sizes suitable for laboratory equipment. Here, we review recent progress in compact intensity-based readout systems for point-of-care (POC) applications. We briefly introduce PCSs as sensitive optical transducers and introduce different approaches for intensity-based readout systems. Photometric measurements have been realized with a simple combination of a light source and a photodetector. Recently a 96-channel, intensity-based readout system for both biochemical interaction analyses as well as cellular assays was presented employing the intensity change of a near cut-off mode. As an alternative for multiparametric detection, a camera system for imaging detection has been implemented. A portable, camera-based system of size 13 cm × 4.9 cm × 3.5 cm with six detection areas on an RWG surface area of 11 mm × 7 mm has been demonstrated for the parallel detection of six protein binding kinetics. The signal-to-noise ratio of this system corresponds to a limit of detection of 168 M (24 ng/ml). To further improve the signal-to-noise ratio advanced nanostructure designs are investigated for RWGs. Here, results on multiperiodic and deterministic aperiodic nanostructures are presented. These advanced nanostructures allow for the design of the number and wavelengths of the RWG resonances. In the context of intensity-based readout systems they are particularly interesting for the realization of multi-LED systems. These recent trends suggest that compact point-of-care systems employing disposable test chips with RWG functional areas may reach market in the near future.

  16. Theory and modelling of optical waveguide sensors utilising surface plasmon resonance

    NARCIS (Netherlands)

    Ctyroky, J.; Homola, J.; Lambeck, Paul; Musa, S.; Musa, A.M.S.; Hoekstra, Hugo; Harris, R.D.; Wilkinson, J.S.; Usievich, B.; Lyndin, N.M.


    A theoretical analysis of the phenomenon of excitation of surface plasma waves in integrated-optical waveguide structures is carried out. Rigorous approach to analysis of light propagation through a waveguide structure with a thin metal overlayer supporting surface plasma waves is formulated using a

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

    Directory of Open Access Journals (Sweden)

    Zhidong Zhang


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

  18. High-order coplanar waveguide (CPW) filters implemented by means of open split ring resonators (OSRRs) and open complementary split ring resonators (OCSRRs) (United States)

    Durán-Sindreu, Miguel; Vélez, Paris; Bonache, Jordi; Martín, Ferran


    In this paper, it is demonstrated that transmission lines loaded with a combination of open split ring resonators (OSRRs) and open complementary split ring resonators (OCSRRs) are useful for the design of high-order band pass filters subjected to standard responses. Specifically, we present a 7-pole Chebyshev band pass filter in coplanar waveguide technology. The device is compact and filter performance is good, including a wide stopband response. With this work, we extend our previous work on the applications of OSRR- and OCSRR-loaded lines to the design of highly selective filters.

  19. Silicon-Nitride-based Integrated Optofluidic Biochemical Sensors using a Coupled-Resonator Optical Waveguide

    Directory of Open Access Journals (Sweden)

    Jiawei eWANG


    Full Text Available Silicon nitride (SiN is a promising material platform for integrating photonic components and microfluidic channels on a chip for label-free, optical biochemical sensing applications in the visible to near-infrared wavelengths. The chip-scale SiN-based optofluidic sensors can be compact due to a relatively high refractive index contrast between SiN and the fluidic medium, and low-cost due to the complementary metal-oxide-semiconductor (CMOS-compatible fabrication process. Here, we demonstrate SiN-based integrated optofluidic biochemical sensors using a coupled-resonator optical waveguide (CROW in the visible wavelengths. The working principle is based on imaging in the far field the out-of-plane elastic-light-scattering patterns of the CROW sensor at a fixed probe wavelength. We correlate the imaged pattern with reference patterns at the CROW eigenstates. Our sensing algorithm maps the correlation coefficients of the imaged pattern with a library of calibrated correlation coefficients to extract a minute change in the cladding refractive index. Given a calibrated CROW, our sensing mechanism in the spatial domain only requires a fixed-wavelength laser in the visible wavelengths as a light source, with the probe wavelength located within the CROW transmission band, and a silicon digital charge-coupled device (CCD / CMOS camera for recording the light scattering patterns. This is in sharp contrast with the conventional optical microcavity-based sensing methods that impose a strict requirement of spectral alignment with a high-quality cavity resonance using a wavelength-tunable laser. Our experimental results using a SiN CROW sensor with eight coupled microrings in the 680nm wavelength reveal a cladding refractive index change of ~1.3 × 10^-4 refractive index unit (RIU, with an average sensitivity of ~281 ± 271 RIU-1 and a noise-equivalent detection limit (NEDL of 1.8 ×10^-8 RIU ~ 1.0 ×10^-4 RIU across the CROW bandwidth of ~1 nm.

  20. Composite right/left-handed coplanar waveguide band-pass filter using capacitively-coupled zeroth-order resonators (United States)

    Li, C.; Liu, K.-Y.; Li, F.


    Design and performance of a coplanar waveguide (CPW) bandpass filter (BPF) using composite right/left-handed (CRLH) zeroth-order resonators have been studied. The unit cell of the CRLH CPW consists of a series interdigital capacitor and two shunt stub inductors embedded between two sections of CPWs. The Bloch analysis is applied based on the S parameters to derive the characteristics of the eigen modes (Bloch modes), from which the right/left-handed frequency band and the zeroth-order resonant frequency are clearly determined. Then, the susceptance slope parameter of the resonator is extracted and the admittance (J-) inverters are introduced to synthesize a capacitively coupled CPW BPF. The measured performance agrees with the simulated one. They show that the size of the filter is greatly reduced (more than 60%) when compared to a conventional structure.

  1. Study of propagation modes of bent waveguides and micro-ring resonators by means of the aperiodic Fourier modal method (United States)

    Bucci, Davide; Martin, Bruno; Morand, Alain


    In the last years, several numerical methods have been studied and applied to the analysis of high index contrast bent waveguides. Very often, the problem is treated using a conformal mapping, which translates the bending into an equivalent graded index profile and a straight waveguide. In this article, we discuss the implementation of a full vectorial 2D mode solver by means of the Aperiodic Fourier Modal Method, developed directly in cylindrical coordinates. This does not require the conformal mapping technique. In the first part of our work, we develop a shorthand notation and the mathematical rules useful to describe the problem in a matrix form. The calculation of propagation modes is then reconducted to the search of eigenvectors of a matrix. We will at first confront our formulation in 1D with results described in the literature. In a second time, we will use the complete 2D solver to determine the resonance frequencies and the quality factors of micro-ring resonators made on silicon surrounded by silica. These characteristics are indeed related to the real and imaginary parts of the propagation constants. By comparison with 3D-FDTD analysis, we will show that our implementation can be used to accurately describe the behavior of micro-rings having a bending radius as low as 1.1 μm in the near infrared region. This technique is general and can be applied to any micro-ring having an arbitrary cross-section and a quality factor which is less than 10000. Perspectives of this work include the study of the field propagation in a bent structure, as well as the coupling between micro-ring resonators and straight waveguides.

  2. Demonstration of photon-photon resonance peak enhancement by waveguide configuration modification on active multimode interferometer laser diode (United States)

    Kitano, Takuya; Nasir Uddin, Mohammad; Hong, Bingzhou; Tajima, Akio; Jiang, Haisong; Hamamoto, Kiichi


    The recent rapid growth of data traffic is leading to high-speed communication for local areas, such as the fiber-to-the-home service. A semiconductor laser is used for such a purpose; however, there is the difficulty that an even higher frequency response occurs in only carrier-photon resonance. For this reason, it is effective to use a second resonance, such as a photon-photon resonance (PPR), for enhancing the frequency response, and the active multimode interferometer laser diode (active-MMI LD) is one of the candidates for achieving a high PPR frequency. In order to obtain an even higher PPR frequency, we have investigated the control scheme of enhancing PPR. In this work, we compared two types of active-MMI waveguide structures to confirm the scheme. As a result, a 3.8 GHz enhancement of the PPR peak, resulting in a 3 dB lower frequency response of 17 GHz, has been successfully achieved by waveguide geometry modification.

  3. Study of all-polymer-based waveguide resonant gratings and their applications for optimization of second-harmonic generation (United States)

    Hoang Luong, Mai; Thanh Ngan Nguyen, Thi; Thanh Nguyen, Chi; Ledoux-Rak, Isabelle; Diep Lai, Ngoc


    We investigated theoretically and experimentally the optical properties of all-polymer-based one-dimensional waveguide resonant gratings (WRGs) and their important applications for the optimization of second-harmonic generation (SHG). We first studied the basic theory of the resonant modes of a simple grating-coupled waveguide realized on a material possessing a low refractive index contrast. The optical properties of any WRG were numerically simulated by using the finite-difference time domain method, performed by commercial Lumerical software. The polymer-based surface relief gratings were fabricated on azopolymer Disperse Red 1-Poly-Methyl-Methacrylate (DR1-PMMA) thin films by using the two-beam interference method and mass transport effect. Their experimental reflection spectra measured as a function of incident light wavelength are in good agreement with the theoretical predictions. We then demonstrated a first application of such a polymer-based WRG for nonlinear optics. Thanks to the strong local electrical field in the WRG, due to a guided-mode resonance condition, the SHG signal of an infrared light beam was strongly enhanced by a factor of 25 as compared to the result obtained in a sample without a grating.

  4. Electro-optic coefficient mapping and the design, fabrication and analysis of coplanar waveguide resonators in lithium niobate (United States)

    Narayan, Raghuram


    The main topics in this dissertation are (a) Investigation of Electro-Optic (EO) coefficient variation in lithium niobate and (b) the design, fabrication and analysis of coplanar waveguide resonant electrodes for EO modulators. An optical sampling technique is used to determine the EO coefficient variations in lithium niobate processed using the titanium in-diffusion technique and the Annealed Proton Exchange (APE) technique. A spatial mapping of the EO coefficients in lithium niobate is presented. The measurements enable us to quantitatively estimate the reduction in the EO coefficient as a function of the processing conditions. The results clearly indicate that samples processed using titanium in-diffusion show no degradation of the EO coefficient. Samples processed using the APE technique display a dramatic drop in the processed region immediately after the proton exchange step. Thermal annealing is shown to restore the EO coefficient in the proton exchanged regions. But the efficacy of thermal annealing is dependent on the initial proton exchange process. Prolonged thermal annealing is effective in restoring the EO coefficients provided the initial proton exchange depth is less than 1.5/mu m. Coplanar Waveguide (CPW) is a popular planar transmission line because of its tight confinement and non-dispersive nature at high frequencies (>60 GHz). In this dissertation, several CPW resonant electrodes have been fabricated, tested and analyzed. The advantage of CPW resonant electrode structure is that there is an enhancement in the field strength by a factor proportional to /sqrt[Q], where Q is the quality factor of the resonator. The dis-advantage is that the device is narrow-band in its frequency response. The focus of this dissertation is to investigate the design and fabrication issues related to CPW resonators. The results indicate the need for better design tools to properly predict the performance of the resonator and in general CPW structures. The measurements

  5. Conductor-backed coplanar waveguide resonators of Y-Ba-Cu-O and Tl-Ba-Ca-Cu-O on LaAlO3 (United States)

    Miranda, F. A.; Bhasin, K. B.; Stan, M. A.; Kong, K. S.; Itoh, T.


    Conductor-backed coplanar waveguide (CBCPW) resonators operating at 10.8 GHz have been fabricated from Tl-Ba-Ca-O (TBCCO) and Y-Ba-Cu-O (YBCO) thin films on LaAlO3. The resonators consist of a coplanar waveguide (CPW) patterned on the superconducting film side of the LaAlO3 substrate with a gold ground plane coated on the opposite side. These resonators were tested in the temperature range from 14 to 106 K. At 77 K, the best of our TBCCO and YBCO resonators have an unloaded quality factor (Qo) 7 and 4 times, respectively, larger than that of a similar all-gold resonator. In this study, the Qo's of the TBCCO resonators were larger than those of their YBCO counterparts throughout the aforementioned temperature range.

  6. Conductor-backed coplanar waveguide resonators of Y-Ba-Cu-O and Tl-Ba-Ca-Cu-O on LaAlO[sub 3

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, F.A.; Bhasin, K.B.; Stan, M.A.; Kong, K.S.; Itoh, T.


    Conductor-backed coplanar waveguide (CBCPW) resonators operating at 10.8 GHz have been fabricated from Tl-Ba-Ca-O (TBCCO) and Y-Ba-Cu-O (YBCO) thin films on LaAlO[sub 3]. The resonators consist of a coplanar waveguide (CPW) patterned on the superconducting film side of the LaAlO3 substrate with a gold ground plane coated on the opposite side. These resonators were tested in the temperature range from 14 to 106 K. At 77 K, the best of our TBCCO and YBCO resonators have an unloaded quality factor (Qo) 7 and 4 times, respectively, larger than that of a similar all-gold resonator. In this study, the Qo's of the TBCCO resonators were larger than those of their YBCO counterparts throughout the aforementioned temperature range.

  7. Fabrication of a terahertz quantum-cascade laser with a double metal waveguide based on multilayer GaAs/AlGaAs heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Khabibullin, R. A., E-mail:; Shchavruk, N. V.; Pavlov, A. Yu.; Ponomarev, D. S.; Tomosh, K. N.; Galiev, R. R.; Maltsev, P. P. [Russian Academy of Sciences, Institute of Ultrahigh Frequency Semiconductor Electronics (Russian Federation); Zhukov, A. E.; Cirlin, G. E.; Zubov, F. I.; Alferov, Zh. I. [Russian Academy of Sciences, Saint Petersburg Academic University—Nanotechnology Research and Education Center (Russian Federation)


    The Postgrowth processing of GaAs/AlGaAs multilayer heterostructures for terahertz quantumcascade lasers (QCLs) are studied. This procedure includes the thermocompression bonding of In–Au multilayer heterostructures with a doped n{sup +}-GaAs substrate, mechanical grinding, and selective wet etching of the substrate, and dry etching of QCL ridge mesastripes through a Ti/Au metallization mask 50 and 100 μm wide. Reactive-ion-etching modes with an inductively coupled plasma source in a BCl{sub 3}/Ar gas mixture are selected to obtain vertical walls of the QCL ridge mesastripes with minimum Ti/Au mask sputtering.

  8. Tunable plasmon-induced absorption effects in a graphene-based waveguide coupled with graphene ring resonators (United States)

    Huang, Pei-Nian; Xia, Sheng-Xuan; Fu, Guang-Lai; Liang, Mei-Zhen; Qin, Meng; Zhai, Xiang; Wang, Ling-Ling


    In this paper, we propose a structure composed of two graphene waveguides and dual coupled graphene ring resonators (GRRs) to achieve a plasmon-induced absorption (PIA) effect. A three-level plasmonic system and a temporal coupled mode theory (CMT) are utilized to verify the simulation results. Moreover, a double-window-PIA effect can be conveniently attained by introducing another GRR with proper parameters to meet more specific acquirement in optical modulation process. The pronounced PIA resonances can be tuned in a number of ways, such as by adjusting the coupling distance between the GRRs and the couplings between the GRR and the waveguide, and tuning the radius and the Fermi energy of the GRRs. Besides, the produced PIA effect shows a high group delay up to - 1 . 87 ps, exhibiting a particularly prominent fast-light feature. Our results have potential applications in the realization of THz-integrated spectral control and graphene plasmonic devices such as sensors, filters, ultra-fast optical switches and so on.

  9. Performance Analysis of Triple Asymmetrical Optical Micro Ring Resonator with 2 × 2 Input-Output Bus Waveguide (United States)

    Ranjan, Suman; Mandal, Sanjoy


    Modeling of triple asymmetrical optical micro ring resonator (TAOMRR) in z-domain with 2 × 2 input-output system with detailed design of its waveguide configuration using finite-difference time-domain (FDTD) method is presented. Transfer function in z-domain using delay-line signal processing technique of the proposed TAOMRR is determined for different input and output ports. The frequency response analysis is carried out using MATLAB software. Group delay and dispersion characteristics are also determined in MATLAB. The electric field analysis is done using FDTD. The method proposes a new methodology to design and draw multiple configurations of coupled ring resonators having multiple in and out ports. Various important parameters such as coupling coefficients and FSR are also determined.

  10. Performance Analysis of Triple Asymmetrical Optical Micro Ring Resonator with 2 × 2 Input-Output Bus Waveguide (United States)

    Ranjan, Suman; Mandal, Sanjoy


    Modeling of triple asymmetrical optical micro ring resonator (TAOMRR) in z-domain with 2 × 2 input-output system with detailed design of its waveguide configuration using finite-difference time-domain (FDTD) method is presented. Transfer function in z-domain using delay-line signal processing technique of the proposed TAOMRR is determined for different input and output ports. The frequency response analysis is carried out using MATLAB software. Group delay and dispersion characteristics are also determined in MATLAB. The electric field analysis is done using FDTD. The method proposes a new methodology to design and draw multiple configurations of coupled ring resonators having multiple in and out ports. Various important parameters such as coupling coefficients and FSR are also determined.

  11. Resonant photonic crystals based on van der Waals heterostructures for effective light pulse retardation (United States)

    Kazanov, D. R.; Poshakinskiy, A. V.; Shubina, T. V.


    We propose to use 2D monolayers possessing optical gaps and high exciton oscillator strength as an element of one-dimensional resonant photonic crystals. We demonstrate that such systems are promising for the creation of effective and compact delay units. In transition-metal-dichalcogenide-based structures where the frequencies of Bragg and exciton resonances are close, a propagating short pulse can be slowed down by few picoseconds while pulse intensity decreases only 2-5 times. This is realized at the frequency of the ;slow; mode situated within the stopband. The pulse retardation and attenuation can be controlled by detuning the Bragg frequency from the exciton resonance frequency.

  12. Analysis of a flip-chip bonded tunable high-temperature superconducting coplanar waveguide resonator using the conformal mapping technique

    Energy Technology Data Exchange (ETDEWEB)

    Misra, M [Research Center for Superconductor Photonics, Osaka University, Osaka 565 0871 (Japan); Kataria, N D [Research Center for Superconductor Photonics, Osaka University, Osaka 565 0871 (Japan); Murakami, H [Research Center for Superconductor Photonics, Osaka University, Osaka 565 0871 (Japan); Tonouchi, M [Research Center for Superconductor Photonics, Osaka University, Osaka 565 0871 (Japan)


    We have studied the tuning properties of a high-temperature superconducting (HTS) half-wavelength coplanar waveguide (CPW) resonator operating at 5 GHz. The tuning schemes are based on flip-chip bonding of an electrically tunable ferroelectric (FE) thin film and a mechanically movable low-loss single crystal on top of the resonator. Using the conformal mapping method, closed-form analytical expressions have been derived for a flip-chip bonded conductor-backed and top-shielded CPW transmission line. The obtained expressions are used to analyse the volume effect of the FE thin film and the gap between the flip-chip and the CPW resonator on the tuning properties of the device. It has been found that large frequency modulation of the resonator produces impedance mismatch, which can considerably enhance the insertion loss of high-performance HTS microwave devices. Analysis also suggests that, for electrically tunable devices, flip-chip bonded FE thin films on HTS CPW devices provide a relatively higher performance compared to bilayer HTS/FE tunable devices.

  13. Analysis of a flip-chip bonded tunable high-temperature superconducting coplanar waveguide resonator using the conformal mapping technique

    CERN Document Server

    Misra, M; Murakami, H; Tonouchi, M


    We have studied the tuning properties of a high-temperature superconducting (HTS) half-wavelength coplanar waveguide (CPW) resonator operating at 5 GHz. The tuning schemes are based on flip-chip bonding of an electrically tunable ferroelectric (FE) thin film and a mechanically movable low-loss single crystal on top of the resonator. Using the conformal mapping method, closed-form analytical expressions have been derived for a flip-chip bonded conductor-backed and top-shielded CPW transmission line. The obtained expressions are used to analyse the volume effect of the FE thin film and the gap between the flip-chip and the CPW resonator on the tuning properties of the device. It has been found that large frequency modulation of the resonator produces impedance mismatch, which can considerably enhance the insertion loss of high-performance HTS microwave devices. Analysis also suggests that, for electrically tunable devices, flip-chip bonded FE thin films on HTS CPW devices provide a relatively higher performance...

  14. Method proposing a slow light ring resonator structure coupled with a metal-dielectric-metal waveguide system based on plasmonic induced transparency. (United States)

    Keleshtery, Mehdi Hassani; Kaatuzian, Hassan; Mir, Ali; Zandi, Ashkan


    We demonstrate the analogue of electromagnetically induced transparency (EIT) in a metal-dielectric-metal (MDM) plasmonic waveguide. Plasmonic induced transparency is a method similar to EIT. In this paper, a plasmonic MDM waveguide is proposed by using an ellipse shaped side-coupled ring resonator and simulated by finite difference time domain. Plasmonics as a new field of chip-scale technology is an interesting substrate, which is used to propose and numerically investigate a novel MDM structure. The aforementioned framework is a 2×2 plasmonic ring resonator, employing gold as a metal and polymethyl methacrylate as a dielectric. Simulations show that a transparent window is located at 1550 nm and signal wavelength is assumed to be 860 nm, which is the phenomenon of plasmonic induced transparency. The velocity of the plasmonic mode can be considerably slowed while propagating along the MDM bends. Our proposed configuration may thus be applied to storing and stopping light in plasmonic waveguide bends. This plasmonic waveguide system may find important applications for multichannel plasmonic filters, nano-scale optical switching, delay time devices, and slow-light devices in highly integrated optical circuits and networks. In comparison with our previous theoretical work based on circular shaped ring resonators, it is shown that ellipse shaped ring resonators demonstrate better specifications with a slow down factor estimated to be more than 30.

  15. Tuning characteristic of band gap and waveguide in a multi-stub locally resonant phononic crystal plate

    Directory of Open Access Journals (Sweden)

    Xiao-Peng Wang


    Full Text Available In this paper, the tuning characteristics of band gaps and waveguides in a locally resonant phononic crystal structure, consisting of multiple square stubs deposited on a thin homogeneous plate, are investigated. Using the finite element method and supercell technique, the dispersion relationships and power transmission spectra of those structures are calculated. In contrast to a system of one square stub, systems of multiple square stubs show wide band gaps at lower frequencies and an increased quantity of band gaps at higher frequencies. The vibration modes of the band gap edges are analyzed to clarify the mechanism of the generation of the lowest band gap. Additionally, the influence of the stubs arrangement on the band gaps in multi-stub systems is investigated. The arrangements of the stubs were found to influence the band gaps; this is critical to understand for practical applications. Based on this finding, a novel method to form defect scatterers by changing the arrangement of square stubs in a multi-stub perfect phononic crystal plate was developed. Defect bands can be induced by creating defects inside the original complete band gaps. The frequency can then be tuned by changing the defect scatterers’ stub arrangement. These results will help in fabricating devices such as acoustic filters and waveguides whose band frequency can be modulated.

  16. TiN superconducting coplanar waveguide resonators with single-photon quality factors of 1.5 million (United States)

    Calusine, Greg; Rosenberg, Danna; Hover, David; Das, Rabindra; Melville, Alexander; Miloshi, Xhovalin; Woods, Wayne; Yoder, Jonilyn; Oliver, William

    The investigation of loss mechanisms in superconducting coplanar waveguide (CPW) resonator provides an efficient means to elucidate relevant loss mechanisms affecting superconducting qubit circuits. As compared to superconducting qubits, the reduced complexity of CPW fabrication coupled with the straightforward characterization of CPW properties facilitates the deconvolution of the impact of individual fabrication steps on the CPW performance. We assess this impact by characterizing the statistically significant differences in internal quality factors (Qi) at the single-photon level resulting from different fabrication processes in aluminum and titanium nitride (TiN) superconducting thin film CPW resonators on silicon. We demonstrate repeatable Qi's at the single-photon level of approximately 1.5x10 in TiN CPW resonators with 90 percent of devices showing Qi's above 1x106 and single Qi's as high as 3.8x106. This work is sponsored in part by the Laboratory for Physical Science, IARPA, and the Assistant Secretary of Defense for Research and Engineering under Air Force Contract FA8721-05-0002. Opinions, interpretations, conclusions, and recommendations are those of the authors and are not necessarily endorsed by the United States Government.

  17. Metamaterial Loadings for Waveguide Miniaturization

    CERN Document Server

    Odabasi, H


    We show that a rectangular metallic waveguide loaded with metamaterial elements consisting of electric-field coupled (ELC) resonators placed at the side walls can operate well below the cutoff frequency of the respective unloaded waveguide. The dispersion diagrams indicate that propagating modes in ELC-loaded waveguides are of forward-type for both TE and TM modes. We also study the dispersion diagram and transmission characteristics of rectangular metallic waveguides simultaneously loaded with ELCs and split ring resonators (SRRs). Such doubly-loaded waveguides can support both forward wave and backward waves, and provide independent control of the propagation characteristics for the respective modes.

  18. Ultracompact ring resonator microwave photonic filters based on photonic crystal waveguides. (United States)

    Shen, Guansheng; Tian, Huiping; Ji, Yuefeng


    We design two microwave photonic filters (notch filter and bandpass filter) based on silicon on insulator (SOI) photonic crystal waveguides for a 60 GHz single-sideband signal radio-over-fiber (ROF) system. By perturbing the radii of the first two rows of holes adjacent to the photonic crystal waveguide, we obtained a broad negligible dispersion bandwidth and a corresponding constant low group velocity. With the slow light effect, the delay line of filters can be significantly reduced while providing the same delay time as fiber based delay lines. The simulation results show that the delay-line length of the notch filter is only about 25.9 μm, and it has a free spectral range of 130 GHz, a baseband width (BW) of 4.12 GHz, and a notch depth of 22 dB. The length of the bandpass filter is 62.4 μm, with a 19.6 dB extinction ratio and a 4.02 GHz BW, and the signal-to-noise ratio requirement of received data can be reduced by 9 dB for the 10(-7) bit-error ratio. Demonstrated microwave photonic crystal filters could be used in a future high-frequency millimeter ROF system.

  19. Electrochemical Surface Plasmon Resonance (EC-SPR) and Waveguide Enhanced Glucose Biosensing with N-Alkylaminated Polypyrrole/Glucose Oxidase Multilayers (United States)

    Baba, Akira; Taranekar, Prasad; Ponnapati, Ramakrishna R.; Knoll, Wolfgang; Advincula, Rigoberto C.


    In this work, we report an electrochemical surface plasmon resonance/waveguide (EC-SPR/waveguide) glucose biosensor, which could detect enzymatic reactions in a conducting polymer/glucose oxidase (GOx) multilayer thin film. In order to achieve a controlled enzyme electrode and waveguide mode, GOx (negatively charged) was immobilized with a water-soluble conducting N-alkylaminated polypyrrole (positively charged) using the layer-by-layer (LbL) electrostatic self-assembly technique. The electrochemical and optical signals were simultaneously obtained from the composite LbL enzyme electrode upon addition of glucose as mediated by the electroactivity and electrochromic property of the polypyrrole layers. The signal enhancement in the EC-SPR detection is obtained by monitoring the doping-dedoping events on the polypyrrole. The real time optical signal could be distinguished between the change in the dielectric constant of the enzyme layer and other non-enzymatic reaction events such as adsorption of glucose and change of refractive index of solution. This was possible by a correlation of both the SPR mode, m=0, and m=1 mode of the waveguide in an SPR/waveguide spectroscopy experiment. PMID:20666478

  20. Dual-Band Dual-Mode Substrate Integrated Waveguide Filters with Independently Reconfigurable TE101 Resonant Mode. (United States)

    Wu, Yongle; Chen, Yuqing; Jiao, Lingxiao; Liu, Yuanan; Ghassemlooy, Zabih


    A novel perturbation approach using additional metalized via-holes for implementation of the dual-band or wide-band dual-mode substrate integrated waveguide (SIW) filters is proposed in this paper. The independent perturbation on the first resonant mode TE101 can be constructed by applying the proposed perturbation approach, whereas the second resonant mode TE102 is not affected. Thus, new kinds of dual-band or wide-band dual-mode SIW filters with a fixed or an independently reconfigurable low-frequency band have been directly achieved. In order to experimentally verify the proposed design method, four two-cavity dual-band SIW filters, which have different numbers of perturbation via-holes in each cavity, and a two-cavity dual-band SIW filter, which includes four via-holes and eight reconfigurable states in each cavity, are designed and experimentally assessed. The measured results indicate that the available frequency-ratio range from 1 to 1.3 can be realized by using four two-cavity dual-band SIW filters. The center frequency of the first band can be tuned from 4.61 GHz to 5.24 GHz, whereas the center frequency of the second one is fixed at around 6.18 GHz for the two-cavity dual-band SIW filter with four reconfigurable states via-holes. All the simulated and measured results show an acceptable agreement with the predicted data.

  1. Comparison of Surface Plasmon Resonance, Resonant Waveguide Grating Biosensing and Enzyme Linked Immunosorbent Assay (ELISA in the Evaluation of a Dengue Virus Immunoassay

    Directory of Open Access Journals (Sweden)

    Joe Buechler


    Full Text Available Two label-free biosensor platforms, Resonance Waveguide Grating (RWG and Surface Plasmon Resonance (SPR, were used to rank a large panel of anti-dengue virus NS1 antibodies. Dengue non-structural 1 (NS1 protein is an established serological marker for the early detection of dengue infection. A variety of commercial dengue NS1 antigen capture immunoassays are available in both ELISA and lateral flow format. However, there is a significant scope to improve both the sensitivity and the specificity of those tests. The interactions of antibody (Ab-antigen (Ag were profiled, with weak interactions (KD = 1–0.1 μM able to be detected under static equilibrium conditions by RWG, but not observed to under more rigorous flow conditions using SPR. There were significant differences in the absolute affinities determined by the two technologies, and there was a poor correlation between antibodies best ranked by RWG and the lower limit of detection (LLOD found by ELISA. Hence, whilst high-throughput RWG can be useful as preliminary screening for higher affinity antibodies, care should be exercised in the assignation of quantitative values for affinity between different assay formats.

  2. Zero-group-velocity acoustic waveguides for high-frequency resonators (United States)

    Caliendo, C.; Hamidullah, M.


    The propagation of the Lamb-like modes along a silicon-on-insulator (SOI)/AlN thin supported structure was simulated in order to exploit the intrinsic zero group velocity (ZGV) features to design electroacoustic resonators that do not require metal strip gratings or suspended edges to confine the acoustic energy. The ZGV resonant conditions in the SOI/AlN composite plate, i.e. the frequencies where the mode group velocity vanishes while the phase velocity remains finite, were investigated in the frequency range from few hundreds of MHz up to 1900 MHz. Some ZGV points were found that show up mostly in low-order modes. The thermal behaviour of these points was studied in the  ‑30 to 220 °C temperature range and the temperature coefficients of the ZGV resonant frequencies (TCF) were estimated. The behaviour of the ZGV resonators operating as gas sensors was studied under the hypothesis that the surface of the device is covered with a thin polyisobutylene (PIB) film able to selectively adsorb dichloromethane (CH2Cl2), trichloromethane (CHCl3), carbontetrachloride (CCl4), tetrachloroethylene (C2Cl4), and trichloroethylene (C2HCl3), at atmospheric pressure and room temperature. The sensor sensitivity to gas concentration in air was simulated for the first four ZGV points of the inhomogeneous plate. The feasibility of high-frequency, low TCF electroacoustic micro-resonator based on SOI and piezoelectric thin film technology was demonstrated by the present simulation study.

  3. On-chip beamsplitter operation on single photons from quasi-resonantly excited quantum dots embedded in GaAs rib waveguides

    Energy Technology Data Exchange (ETDEWEB)

    Rengstl, U.; Schwartz, M.; Herzog, T.; Hargart, F.; Paul, M.; Portalupi, S. L.; Jetter, M.; Michler, P., E-mail: [Institut für Halbleiteroptik und Funktionelle Grenzflächen and Research Center SCoPE, University of Stuttgart, Allmandring 3, 70569 Stuttgart (Germany)


    We present an on-chip beamsplitter operating on a single-photon level by means of a quasi-resonantly driven InGaAs/GaAs quantum dot. The single photons are guided by rib waveguides and split into two arms by an evanescent field coupler. Although the waveguides themselves support the fundamental TE and TM modes, the measured degree of polarization (∼90%) reveals the main excitation and propagation of the TE mode. We observe the preserved single-photon nature of a quasi-resonantly excited quantum dot by performing a cross-correlation measurement on the two output arms of the beamsplitter. Additionally, the same quantum dot is investigated under resonant excitation, where the same splitting ratio is observed. An autocorrelation measurement with an off-chip beamsplitter on a single output arm reveal the single-photon nature after evanescent coupling inside the on-chip splitter. Due to their robustness, adjustable splitting ratio, and their easy implementation, rib waveguide beamsplitters with embedded quantum dots provide a promising step towards fully integrated quantum circuits.

  4. Quantitative Subsurface Atomic Structure Fingerprint for 2D Materials and Heterostructures by First-Principles-Calibrated Contact-Resonance Atomic Force Microscopy. (United States)

    Tu, Qing; Lange, Björn; Parlak, Zehra; Lopes, Joao Marcelo J; Blum, Volker; Zauscher, Stefan


    Interfaces and subsurface layers are critical for the performance of devices made of 2D materials and heterostructures. Facile, nondestructive, and quantitative ways to characterize the structure of atomically thin, layered materials are thus essential to ensure control of the resultant properties. Here, we show that contact-resonance atomic force microscopy-which is exquisitely sensitive to stiffness changes that arise from even a single atomic layer of a van der Waals-adhered material-is a powerful experimental tool to address this challenge. A combined density functional theory and continuum modeling approach is introduced that yields sub-surface-sensitive, nanomechanical fingerprints associated with specific, well-defined structure models of individual surface domains. Where such models are known, this information can be correlated with experimentally obtained contact-resonance frequency maps to reveal the (sub)surface structure of different domains on the sample.

  5. Comparison of wavelength conversion efficiency between silicon waveguide and microring resonator

    DEFF Research Database (Denmark)

    Xiong, Meng; Ding, Yunhong; Ou, Haiyan


    Wavelength conversion based on degenerate four-wave mixing (FWM) was demonstrated and compared between silicon nanowire and microring resonator (MRR). 15 dB enhancement of conversion efficiency (CE) with relatively low input pump power (5 mW) was achieved experimentally in an MRR. The impacts of ...

  6. Tubular optical waveguide particle plasmon resonance biosensor for multiplex real-time and label-free detection (United States)

    Huang, Chen-Han; Lin, Hsing-Ying; Chau, Lai-Kwan


    A tubular optical waveguide particle plasmon resonance (TW-PPR) sensor is demonstrated for higher-throughput and sensitive label-free biochemical detections. Compared to other evanescent field absorption sensors, the TW-PPR sensor possesses merits of itself being a microchamber of a defined sample volume, a mechanical support for sensor coatings, and ease of systematic multichannel expansion. The sensor resolution is estimated to be 2.6 × 10-6 RIU in measuring solutions of various refractive indices (RIs). Additionally, the multichannel TW-PPR sensing system can perform independent measurements simultaneously and its limit of detection (LOD) of anti-DNP antibody and streptavidin separately measured by DNP-functionalized and biotin-functionalized TW-PPR microchambers is demonstrated to be 1.21 × 10-10 and 2.27 × 10-10 g/ml, respectively. Accurate determinations of these molecules with known concentrations spiked in artificial urine are examined and the sensor responses give excellent correlation with results demonstrated in standard buffer examinations, supporting the utility of the device for analyte screening in more complex media. The TWPPR sensor can be inexpensively fabricated and has a special niche as high-sensitivity refractive index sensor as well as biosensor for label-free monitoring biomolecular interactions in real-time. It is ideally suitable for disposable uses, especially promising for convenient higher-throughput biochemical sensing applications.

  7. Determination of Temperature-Dependent Stress State in Thin AlGaN Layer of AlGaN/GaN HEMT Heterostructures by Near-Resonant Raman Scattering

    Directory of Open Access Journals (Sweden)

    Yanli Liu


    Full Text Available The temperature-dependent stress state in the AlGaN barrier layer of AlGaN/GaN heterostructure grown on sapphire substrate was investigated by ultraviolet (UV near-resonant Raman scattering. Strong scattering peak resulting from the A1(LO phonon mode of AlGaN is observed under near-resonance condition, which allows for the accurate measurement of Raman shifts with temperature. The temperature-dependent stress in the AlGaN layer determined by the resonance Raman spectra is consistent with the theoretical calculation result, taking lattice mismatch and thermal mismatch into account together. This good agreement indicates that the UV near-resonant Raman scattering can be a direct and effective method to characterize the stress state in thin AlGaN barrier layer of AlGaN/GaN HEMT heterostructures.

  8. Thermal waveguide OPO. (United States)

    Lin, S T; Lin, Y Y; Wang, T D; Huang, Y C


    We report a mid-infrared, CW singly resonant optical parametric oscillator (OPO) with a thermally induced waveguide in its gain crystal. We measured a numerical aperture of 0.0062 for the waveguide at 80-W intracavity power at 3.2 microm. This thermal-guiding effect benefits to the stable operation of an OPO and improves the parametric conversion efficiency by more than a factor of two when compared with that without thermal guiding.

  9. A Compact Coplanar Waveguide (CPW)-Fed Zeroth-Order Resonant Filter for Bandpass Applications (United States)

    Choudhary, Dilip Kumar; Chaudhary, Raghvendra Kumar


    A new CPW-fed bandpass filter based on zeroth order resonant (ZOR) technique is presented in this paper. Proposed filter structure is designed on a CPW single layer where via is not required, hence reduces fabrication complexity. The property of metamaterial of ZOR has been utilized to reduce the filter size. The proposed structure is symmetrically CPW-fed and contains tuning-fork stub, which connects patch to CPW ground plane. The metamaterial properties are characterized by plotting dispersion diagram of proposed structure. The experimental result of proposed filter design shows an insertion loss of 0.51 dB, return loss of 22.5 dB with fractional bandwidth 61.5 % at centre frequency 2.60 GHz. The size of the filter is 0.45 λg×0.36 λg (λg is the guided wavelength at centre frequency).

  10. Non-Volatile Ferroelectric Switching of Ferromagnetic Resonance in NiFe/PLZT Multiferroic Thin Film Heterostructures (Postprint) (United States)


    is sensitive to interfacial charge accumulation and depletion, we use voltage control of interfacial charge screening to achieve control over magnetic ...composite structures. Adv. Mater. 22, 2900–2918 (2010). 5. Sun, N. X. & Srinivasan, G. Voltage Control of magnetism in multiferroic heterostructures and...Nan, C. W. Design of a voltage - controlled magnetic random access memory based on anisotropic magnetoresistance in a single magnetic layer. Adv. Mater

  11. Photonic Crystal Waveguide Weakly Interacting with Multiple Off-Channel Resonant Features Formed of Kerr Nonlinear Dielectric Media

    Directory of Open Access Journals (Sweden)

    A. R. McGurn


    a number of analytical results are presented providing simple explanations of the quantitative behaviors of the systems. A relationship of these systems to forms of electromagnetic-induced transparency and modifications of waveguide dispersion relations is discussed.

  12. Design of a High-Performance Micro Integrated Surface Plasmon Resonance Sensor Based on Silicon-On-Insulator Rib Waveguide Array

    Directory of Open Access Journals (Sweden)

    Dengpeng Yuan


    Full Text Available Based on silicon-on-insulator (SOI rib waveguide with large cross-section, a micro integrated surface plasmon resonance (SPR biochemical sensor platform is proposed. SPR is excited at the deeply etched facet of the bend waveguide by the guiding mode and a bimetallic configuration is employed. With the advantages of SOI rib waveguide and the silicon microfabrication technology, an array of the SPR sensors can be composed to implement wavelength interrogation of the sensors’ output signal, so the spectrometer or other bulky and expensive equipment are not necessary, which enables the SPR sensor to realize the miniaturization and integration of the entire sensing system. The performances of the SPR sensor element are verified by using the two-dimensional finite-different time-domain method. The parameters of the sensor element and the array are optimized for the achievement of high performance for biochemical sensing application. As a typical example, a single bimetallic SPR sensor with 3 nm Au over 32 nm Al possesses a high sensitivity of 3.968 × 104 nm/RIU, a detection-accuracy of 14.7 μm−1. For a uniparted SPR sensor, it can achieve a detection limit of 5.04 × 10−7 RIU. With the relative power measurement accuracy of 0.01 dB, the refractive index variation of 1.14 × 10−5 RIU can be detected by the SPR sensor array.

  13. Low-power, ultrafast, and dynamic all-optical tunable plasmon induced transparency in two stub resonators side-coupled with a plasmonic waveguide system (United States)

    Wang, Boyun; Zeng, Qingdong; Xiao, Shuyuan; Xu, Chen; Xiong, Liangbin; Lv, Hao; Du, Jun; Yu, Huaqing


    We theoretically and numerically investigate a low-power, ultrafast, and dynamic all-optical tunable plasmon induced transparency (PIT) in two stub resonators side-coupled with a metal-dielectric-metal (MDM) plasmonic waveguide system. The optical Kerr effect is enhanced by the local electromagnetic field of surface plasmon polaritons (SPPs) and the plasmonic waveguide based on graphene-Ag composite material structures with large effective Kerr nonlinear coefficient. An ultrafast response time of the order of 1 ps is reached because of ultrafast carrier relaxation dynamics of graphene. With dynamically tuning the propagation phase of the plasmonic waveguide, π-phase shift of the transmission spectrum in the PIT system is achieved under excitation of a pump light with an intensity as low as 5.8 MW cm‑2. The group delay is controlled between 0.14 and 0.67 ps. Moreover, the tunable bandwidth of about 42 nm is obtained. For the indirect coupling between two stub cavities or the phase coupling scheme, the phase shift multiplication effect of the PIT effect is found. All observed schemes are analyzed rigorously through finite-difference time-domain simulations and coupled-mode formalism. This work not only paves the way towards the realization of on-chip integrated nanophotonic devices but also opens the possibility of the construction of ultrahigh-speed information processing chips based on plasmonic circuits.

  14. Terahertz cyclotron resonance spectroscopy of an AlGaN/GaN heterostructure using a high-field pulsed magnet and an asynchronous optical sampling technique

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, B. F., E-mail:; Smith, W. F.; Hibberd, M. T.; Dawson, P.; Graham, D. M. [School of Physics and Astronomy and the Photon Science Institute, The University of Manchester, Manchester M13 9PL (United Kingdom); Beck, M.; Bartels, A. [Laser Quantum GmbH, Max-Stromeyer-Str. 116, 78467 Konstanz (Germany); Guiney, I.; Humphreys, C. J. [Department of Materials Science and Metallurgy, 27 Charles Babbage Road, University of Cambridge, Cambridge CB3 0FS (United Kingdom)


    The effective mass, sheet carrier concentration, and mobility of electrons within a two-dimensional electron gas in an AlGaN/GaN heterostructure were determined using a laboratory-based terahertz cyclotron resonance spectrometer. The ability to perform terahertz cyclotron resonance spectroscopy with magnetic fields of up to 31 T was enabled by combining a high-field pulsed magnet with a modified asynchronous optical sampling terahertz detection scheme. This scheme allowed around 100 transmitted terahertz waveforms to be recorded over the 14 ms magnetic field pulse duration. The sheet density and mobility were measured to be 8.0 × 10{sup 12 }cm{sup −2} and 9000 cm{sup 2} V{sup −1} s{sup −1} at 77 K. The in-plane electron effective mass at the band edge was determined to be 0.228 ± 0.002m{sub 0}.

  15. Giant Electric Field Control of Magnetism and Narrow Ferromagnetic Resonance Linewidth in FeCoSiB/Si/SiO2/PMN PT Multiferroic Heterostructures (Open Access Author’s Manuscript) (United States)


    1 Giant electric field control of magnetism and narrow ferromagnetic resonance linewidth in FeCoSiB/Si/SiO2/PMN-PT multiferroic which the electric field applied to the piezoelectric layer produces a mechanical deformation that couples to the magnetic film, and hence induces...a magnetic anisotropy change, it is promising for one to develop electric field tunable RF devices due to strong ME coupling.11-24

  16. Angular Displacement and Velocity Sensors Based on Coplanar Waveguides (CPWs Loaded with S-Shaped Split Ring Resonators (S-SRR

    Directory of Open Access Journals (Sweden)

    Jordi Naqui


    Full Text Available 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.

  17. Angular Displacement and Velocity Sensors Based on Coplanar Waveguides (CPWs) Loaded with S-Shaped Split Ring Resonators (S-SRR). (United States)

    Naqui, Jordi; Coromina, Jan; Karami-Horestani, Ali; Fumeaux, Christophe; Martín, Ferran


    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.

  18. Loss engineered slow light waveguides. (United States)

    O'Faolain, L; Schulz, S A; Beggs, D M; White, T P; Spasenović, M; Kuipers, L; Morichetti, F; Melloni, A; Mazoyer, S; Hugonin, J P; Lalanne, P; Krauss, T F


    Slow light devices such as photonic crystal waveguides (PhCW) and coupled resonator optical waveguides (CROW) have much promise for optical signal processing applications and a number of successful demonstrations underpinning this promise have already been made. Most of these applications are limited by propagation losses, especially for higher group indices. These losses are caused by technological imperfections ("extrinsic loss") that cause scattering of light from the waveguide mode. The relationship between this loss and the group velocity is complex and until now has not been fully understood. Here, we present a comprehensive explanation of the extrinsic loss mechanisms in PhC waveguides and address some misconceptions surrounding loss and slow light that have arisen in recent years. We develop a theoretical model that accurately describes the loss spectra of PhC waveguides. One of the key insights of the model is that the entire hole contributes coherently to the scattering process, in contrast to previous models that added up the scattering from short sections incoherently. As a result, we have already realised waveguides with significantly lower losses than comparable photonic crystal waveguides as well as achieving propagation losses, in units of loss per unit time (dB/ns) that are even lower than those of state-of-the-art coupled resonator optical waveguides based on silicon photonic wires. The model will enable more advanced designs with further loss reduction within existing technological constraints.

  19. Raman and fluorescence contributions to the resonant inelastic soft x-ray scattering on LaAlO3/SrTiO3 heterostructures (United States)

    Pfaff, F.; Fujiwara, H.; Berner, G.; Yamasaki, A.; Niwa, H.; Kiuchi, H.; Gloskovskii, A.; Drube, W.; Gabel, J.; Kirilmaz, O.; Sekiyama, A.; Miyawaki, J.; Harada, Y.; Suga, S.; Sing, M.; Claessen, R.


    We present a detailed study of the Ti 3 d carriers at the interface of LaAlO3/SrTiO3 heterostructures by high-resolution resonant inelastic soft x-ray scattering (RIXS), with special focus on the roles of overlayer thickness and oxygen vacancies. Our measurements show the existence of interfacial Ti 3 d electrons already below the critical thickness for conductivity. The (total) interface charge carrier density increases up to a LaAlO3 overlayer thickness of 6 unit cells before it levels out. Furthermore, we observe strong Ti 3 d charge carrier doping by oxygen vacancies. The RIXS data combined with photoelectron spectroscopy and transport measurements indicate the simultaneous presence of localized and itinerant charge carriers. At variance with previous interpretations, we show that in our excitation energy dependent RIXS measurements the amounts of localized and itinerant Ti 3 d electrons in the ground state do not scale with the intensities of the Raman and fluorescence peaks, respectively. Rather, we attribute the observation of either Raman components or fluorescence signal to the specific nature of the intermediate state reached in the RIXS excitation process.

  20. Zn-vapor diffused Er:Yb:LiNbO 3 channel waveguides fabricated by means of SiO 2 electron cyclotron resonance plasma deposition (United States)

    Pernas, P. L.; Hernández, M. J.; Ruíz, E.; Cantelar, E.; Nevado, R.; Morant, C.; Lifante, G.; Cussó, F.


    We report here the fabrication method and operation of Zinc-vapor diffused channel waveguides on Erbium/Ytterbium (Er/Yb)-doped Lithium Niobate (LiNbO 3). electron cyclotron resonance (ECR) plasma deposition technique, UV photolithography and Reactive Ion Etching (RIE) are used to define an SiO 2 mask for pattern transfer. The whole process is performed at low temperatures eliminating typical LiO 2 out-diffusion problems and achieving low surface damage. The flexibility of the fabrication technology has been shown to be potentially applicable to integrated optics. EDAX measurements reveal good confinement and homogeneity of the diffused regions. Atomic Force Microscopy (AFM) surface characterization shows the swelling of the diffused areas, consistent with the topoepitaxial growth of a Zn xLi yNb zO w layer.

  1. Low-loss and flatband silicon-nanowire-based 5th-order coupled resonator optical waveguides (CROW) fabricated by ArF-immersion lithography process on a 300-mm SOI wafer (United States)

    Jeong, Seok-Hwan; Shimura, Daisuke; Simoyama, Takasi; Seki, Miyoshi; Yokoyama, Nobuyuki; Ohtsuka, Minoru; Koshino, Keiji; Horikawa, Tsuyoshi; Tanaka, Yu; Morito, Ken


    We present flatband, low-loss and low-crosstalk characteristics of Si-nanowire-based 5th-order coupled resonator optical waveguides (CROW) fabricated by ArF-immersion lithography process on a 300-mm silicon-on-insulator (SOI) wafer. We theoretically specified why phase controllability over Si-nanowire waveguides is prerequisite to attain desired spectral response, discussing spectral degradation by random phase errors during fabrication process. It was experimentally demonstrated that advanced patterning technology based on ArF-immersion lithography process showed extremely low phase errors even for Si-nanowire channel waveguides. As a result, the device exhibited extremely low loss of CROW. We believe these high-precision fabrication technologies based on 300-mm SOI wafer scale ArF-immersion lithography would be promising for several kinds of WDM multiplexers/demultiplexers having much complicated configurations and requiring much finer phase controllability.

  2. Quantum plasmonic waveguides: Au nanowires (United States)

    Cordaro, C. E. A.; Piccitto, G.; Priolo, F.


    Combining miniaturization and good operating speed is a compelling yet crucial task for our society. Plasmonic waveguides enable the possibility of carrying information at optical operating speed while maintaining the dimension of the device in the nanometer range. Here we present a theoretical study of plasmonic waveguides extending our investigation to structures so small that Quantum Size Effects (QSE) become non-negligible, namely quantum plasmonic waveguides. Specifically, we demonstrate and evaluate a blue-shift in Surface Plasmon (SP) resonance energy for an ultra-thin gold nanowire.

  3. Single-chip ring resonator-based 1 x 8 optical beam forming network in CMOS-compatible waveguide technology

    NARCIS (Netherlands)

    Zhuang, L.; Roeloffzen, C.G.H.; Heideman, Rene; Borreman, A.; Meijerink, Arjan; van Etten, Wim


    Optical ring resonators (ORRs) are good candidates to provide continuously tunable delay in optical beam forming networks (OBFNs) for phased array antenna systems. Delay and splitting/combining elements can be integrated on a single optical chip to form an OBFN. A state-of-the-art ring resonator-

  4. Resonant photoelectron spectroscopy of γ-Al{sub 2}O{sub 3}/SrTiO{sub 3} heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Schuetz, Philipp; Pfaff, Florian; Zapf, Michael; Gabel, Judith; Dudy, Lenart; Berner, Goetz; Sing, Michael; Claessen, Ralph [Wuerzburg Univ. (Germany). Physikalisches Inst. and Roentgen Center for Complex Material Systems (RCCM); Chen, Yunzhong; Pryds, Nini [Technical Univ. of Denmark, Risoe (Denmark). Dept. of Energy Conversion and Storage; Rogalev, Victor; Strocov, Vladimir [Paul Scherrer Institut, Villigen (Switzerland). Swiss Light Source; Schlueter, Christoph; Lee, Tien-Lin [Diamond Light Source Ltd., Didcot (United Kingdom)


    The spinel/perovskite heterointerface between the band insulators γ-Al{sub 2}O{sub 3} and SrTiO{sub 3} hosts a two-dimensional electron system (2DES) with exceptionally high electron mobility. Soft X-ray resonant photoelectron spectroscopy at the Ti L absorption edge is used to probe the Ti 3d derived interface states. Marked differences in the resonance behavior are found for the SrTiO{sub 3} valence band and the different interface states, which are observed in the band gap of SrTiO{sub 3}. A comparison to X-ray absorption spectra of Ti 3d{sup 0} and Ti 3d{sup 1} systems reveals the presence of different types of electronic states with Ti 3d character, i.e., oxygen vacancy induced, trapped in-gap states and itinerant states contributing to the 2DES. Furthermore, exposure to low doses of oxygen during irradiation allows for the controlled and reversible manipulation of the interfacial electronic structure, i.e., the in-gap state intensity and the valence band offset between SrTiO{sub 3} and γ-Al{sub 2}O{sub 3}.

  5. Finite-width plasmonic waveguides with hyperbolic multilayer cladding

    DEFF Research Database (Denmark)

    Babicheva, Viktoriia; Shalaginov, Mikhail Y.; Ishii, Satoshi


    Engineering plasmonic metamaterials with anisotropic optical dispersion enables us to tailor the properties of metamaterial-based waveguides. We investigate plasmonic waveguides with dielectric cores and multilayer metal-dielectric claddings with hyperbolic dispersion. Without using any......, are strongly absorbed. By avoiding the resonant widths in the design of the actual waveguides, the strong absorption can be eliminated. (C) 2015 Optical Society of America...

  6. Implementation of single-photon quantum routing and decoupling using a nitrogen-vacancy center and a whispering-gallery-mode resonator-waveguide system. (United States)

    Cao, Cong; Duan, Yu-Wen; Chen, Xi; Zhang, Ru; Wang, Tie-Jun; Wang, Chuan


    Quantum router is a key element needed for the construction of future complex quantum networks. However, quantum routing with photons, and its inverse, quantum decoupling, are difficult to implement as photons do not interact, or interact very weakly in nonlinear media. In this paper, we investigate the possibility of implementing photonic quantum routing based on effects in cavity quantum electrodynamics, and present a scheme for single-photon quantum routing controlled by the other photon using a hybrid system consisting of a single nitrogen-vacancy (NV) center coupled with a whispering-gallery-mode resonator-waveguide structure. Different from the cases in which classical information is used to control the path of quantum signals, both the control and signal photons are quantum in our implementation. Compared with the probabilistic quantum routing protocols based on linear optics, our scheme is deterministic and also scalable to multiple photons. We also present a scheme for single-photon quantum decoupling from an initial state with polarization and spatial-mode encoding, which can implement an inverse operation to the quantum routing. We discuss the feasibility of our schemes by considering current or near-future techniques, and show that both the schemes can operate effectively in the bad-cavity regime. We believe that the schemes could be key building blocks for future complex quantum networks and large-scale quantum information processing.

  7. Dependence of cancer cell adhesion kinetics on integrin ligand surface density measured by a high-throughput label-free resonant waveguide grating biosensor (United States)

    Orgovan, Norbert; Peter, Beatrix; Bősze, Szilvia; Ramsden, Jeremy J.; Szabó, Bálint; Horvath, Robert


    A novel high-throughput label-free resonant waveguide grating (RWG) imager biosensor, the Epic® BenchTop (BT), was utilized to determine the dependence of cell spreading kinetics on the average surface density (vRGD) of integrin ligand RGD-motifs. vRGD was tuned over four orders of magnitude by co-adsorbing the biologically inactive PLL-g-PEG and the RGD-functionalized PLL-g-PEG-RGD synthetic copolymers from their mixed solutions onto the sensor surface. Using highly adherent human cervical tumor (HeLa) cells as a model system, cell adhesion kinetic data of unprecedented quality were obtained. Spreading kinetics were fitted with the logistic equation to obtain the spreading rate constant (r) and the maximum biosensor response (Δλmax), which is assumed to be directly proportional to the maximum spread contact area (Amax). r was found to be independent of the surface density of integrin ligands. In contrast, Δλmax increased with increasing RGD surface density until saturation at high densities. Interpreting the latter behavior with a simple kinetic mass action model, a 2D dissociation constant of 1753 +/- 243 μm-2 (corresponding to a 3D dissociation constant of ~30 μM) was obtained for the binding between RGD-specific integrins embedded in the cell membrane and PLL-g-PEG-RGD. All of these results were obtained completely noninvasively without using any labels.

  8. Design Procedure for Compact Folded Waveguide Filters

    DEFF Research Database (Denmark)

    Dong, Yunfeng; Johansen, Tom Keinicke; Zhurbenko, Vitaliy

    -dimensional full-wave electromagnetic simulations. The proposed structure and the fabricated folded waveguide filter are shown in Fig. 1. A network analyzer (HP8720D) was used to test the fabricated folded waveguide filter. The measurement results are shown in Fig. 2 in comparison with the simulation results......Waveguide filters are widely used in communication systems due to low losses and high power handling capabilities. One drawback of the conventional waveguide filters is their large size, especially for low-frequency and high-order realizations. It has been shown that the footprint of conventional...... waveguide resonators can be reduced to one quarter by folding the electric and magnetic fields inside the cavity (J. S. Hong, Microwave Symposium Digest, 2004, Vol. 1, pp. 213-216). This paper presents a novel systematic procedure for designing compact low-loss bandpass filters by using folded waveguide...

  9. Optimization of metal-clad waveguide sensors

    DEFF Research Database (Denmark)

    Skivesen, N.; Horvath, R.; Pedersen, H.C.


    The present paper deals with the optimization of metal-clad waveguides for sensor applications to achieve high sensitivity for adlayer and refractive index measurements. By using the Fresnel reflection coefficients both the angular shift and the width of the resonances in the sensorgrams are taken...... into account. Our optimization shows that it is possible for metal-clad waveguides to achieve a sensitivity improvement of 600% compared to surface-plasmon-resonance sensors....

  10. Wave-guided optical waveguides

    DEFF Research Database (Denmark)

    Palima, Darwin; Bañas, Andrew Rafael; Vizsnyiczai, George


    in the sample at any orientation using optical traps. One of the key aspects to the work is the change in direction of the incident plane wave, and the marked increase in the numerical aperture demonstrated. Hence, the optically steered waveguide can tap from a relatively broader beam and then generate a more...... tightly confined light at its tip. The paper contains both simulation, related to the propagation of light through the waveguide, and experimental demonstrations using our BioPhotonics Workstation. In a broader context, this work shows that optically trapped microfabricated structures can potentially help...

  11. Detection of amyloid-β42 using a waveguide-coupled bimetallic surface plasmon resonance sensor chip in the intensity measurement mode. (United States)

    Lee, Yeon Kyung; Lee, Kyeong-Seok; Kim, Won Mok; Sohn, Young-Soo


    The waveguide-coupled bimetallic (WcBiM) surface plasmon resonance (SPR) chip had been utilized in the intensity interrogation detection mode to detect amyloid-β42 (Aβ42), a biomarker of the Alzheimer disease. The SPR reflectance curve of the WcBiM chip has the narrower full-width-at-half-maximum (FWHM) compared with the SPR reflectance curve of the conventional gold (Au) chip, resulting in the steeper gradient. For the enhancement of resolution, the light source was fixed at an angle where the slope of the reflectance curve is the steepest, and the change in the reflectance was monitored. For the detection of Aβ42, the antibody of Aβ42 (anti-Aβ42) was immobilized on the WcBiM SPR chip using the self-assembled monolayer. The SPR responses, the average changes in the reflectance to the Aβ42 at the concentrations of 100 pg/ml, 250 pg/ml, 500 pg/ml, 750 pg/ml, 1,000 pg/ml, and 2,000 pg/ml were 0.0111%, 0.0305%, 0.0867%, 0.1712%, 0.3021%, and 0.5577%, respectively, for the three replicates. From linear regression analysis, the calibration curve indicated that the SPR response had a linear relation with Aβ42 with the concentration in the range of 100 pg/ml to 2,000 pg/ml. A control experiment showed the anti-Aβ42-modified surface of the WcBiM chip had a high specificity to Aβ42. Thus, the enhanced resolution by utilizing the WcBiM SPR chip in the intensity interrogation detection mode aids the diagnosis of the Alzheimer disease by detecting the Aβ42 around the criteria concentration (500 pg/ml) without any labeling.

  12. Detection of amyloid-β42 using a waveguide-coupled bimetallic surface plasmon resonance sensor chip in the intensity measurement mode.

    Directory of Open Access Journals (Sweden)

    Yeon Kyung Lee

    Full Text Available The waveguide-coupled bimetallic (WcBiM surface plasmon resonance (SPR chip had been utilized in the intensity interrogation detection mode to detect amyloid-β42 (Aβ42, a biomarker of the Alzheimer disease. The SPR reflectance curve of the WcBiM chip has the narrower full-width-at-half-maximum (FWHM compared with the SPR reflectance curve of the conventional gold (Au chip, resulting in the steeper gradient. For the enhancement of resolution, the light source was fixed at an angle where the slope of the reflectance curve is the steepest, and the change in the reflectance was monitored. For the detection of Aβ42, the antibody of Aβ42 (anti-Aβ42 was immobilized on the WcBiM SPR chip using the self-assembled monolayer. The SPR responses, the average changes in the reflectance to the Aβ42 at the concentrations of 100 pg/ml, 250 pg/ml, 500 pg/ml, 750 pg/ml, 1,000 pg/ml, and 2,000 pg/ml were 0.0111%, 0.0305%, 0.0867%, 0.1712%, 0.3021%, and 0.5577%, respectively, for the three replicates. From linear regression analysis, the calibration curve indicated that the SPR response had a linear relation with Aβ42 with the concentration in the range of 100 pg/ml to 2,000 pg/ml. A control experiment showed the anti-Aβ42-modified surface of the WcBiM chip had a high specificity to Aβ42. Thus, the enhanced resolution by utilizing the WcBiM SPR chip in the intensity interrogation detection mode aids the diagnosis of the Alzheimer disease by detecting the Aβ42 around the criteria concentration (500 pg/ml without any labeling.

  13. Manipulation of magnetic exchange in iridate heterostructures (United States)

    Meyers, D.; Fabbris, G.; Yin, Weiguo; Casa, D.; Cao, Yue; Hao, Lin; Schmitt, T.; Liu, Jian; Dean, M. P. M.

    Artificial layering of disparate materials into superlattices is an emerging method that promises unparalleled versatility in accessing ground states unavailable to bulk synthesis. Heterostructures composed of paramagnetic, metallic SrIrO3 interspaced with band insulating SrTiO3 were found to host a canted antiferromagnetic ground state, mirroring the Ruddlesen-Popper series iridates with enhanced tunability. We investigate the magnetic excitation spectrum of these artificial systems using resonant inelastic x-ray scattering and directly infer the interlayer and intralayer magnetic exchange interactions. Understanding how interfacial effects modify magnetic interactions is a vital prerequisite for efforts to controllably target different ground states within complex oxide-heterostructures.

  14. Evanescent field phase shifting in a silicon nitride waveguide using a coupled silicon slab

    DEFF Research Database (Denmark)

    Jensen, Asger Sellerup; Oxenløwe, Leif Katsuo; Green, William M. J.


    An approach for electrical modulation of low-loss silicon nitride waveguides is proposed, using a silicon nitride waveguide evanescently loaded with a thin silicon slab. The thermooptic phase-shift characteristics are investigated in a racetrack resonator configuration.......An approach for electrical modulation of low-loss silicon nitride waveguides is proposed, using a silicon nitride waveguide evanescently loaded with a thin silicon slab. The thermooptic phase-shift characteristics are investigated in a racetrack resonator configuration....

  15. Metamaterial Waveguide Devices for Integrated Optics (United States)

    Kanazawa, Toru; Yamasaki, Satoshi; Arai, Shigehisa


    We show the feasibility of controlling the magnetic permeability of optical semiconductor devices on InP-based photonic integration platforms. We have achieved the permeability control of GaInAsP/InP semiconductor waveguides by combining the waveguide with a metamaterial consisting of gate-controlled split ring resonators. The split-ring resonators interact magnetically with light travelling in the waveguide and move the effective relative permeability of the waveguide away from 1 at optical frequencies. The variation in permeability can be controlled with the gate voltage. Using this variable-permeability waveguide, we have built an optical modulator consisting of a GaInAsP/InP Mach–Zehnder interferometer for use at an optical communication wavelength of 1.55 μm. The device changes the permeability of its waveguide arm with controlling gate voltage, thereby varying the refractive index of the arm to modulate the intensity of light. For the study of variable-permeability waveguide devices, we also propose a method of extracting separately the permittivity and permeability values of devices from the experimental data of light transmission. Adjusting the permeability of optical semiconductors to the needs of device designers will open the promising field of ‘permeability engineering’. Permeability engineering will facilitate the manipulation of light and the management of photons, thereby contributing to the development of novel devices with sophisticated functions for photonic integration. PMID:28872621

  16. Quantum waveguides

    CERN Document Server

    Exner, Pavel


    This monograph explains the theory of quantum waveguides, that is, dynamics of quantum particles confined to regions in the form of tubes, layers, networks, etc. The focus is on relations between the confinement geometry on the one hand and the spectral and scattering properties of the corresponding quantum Hamiltonians on the other. Perturbations of such operators, in particular, by external fields are also considered. The volume provides a unique summary of twenty five years of research activity in this area and indicates ways in which the theory can develop further. The book is fairly self-contained. While it requires some broader mathematical physics background, all the basic concepts are properly explained and proofs of most theorems are given in detail, so there is no need for additional sources. Without a parallel in the literature, the monograph by Exner and Kovarik guides the reader through this new and exciting field.

  17. Slow-light enhanced subwavelength plasmonic waveguide refractive index sensors. (United States)

    Huang, Yin; Min, Changjun; Dastmalchi, Pouya; Veronis, Georgios


    We introduce slow-light enhanced subwavelength scale refractive index sensors which consist of a plasmonic metal-dielectric-metal (MDM) waveguide based slow-light system sandwiched between two conventional MDM waveguides. We first consider a MDM waveguide with small width structrue for comparison, and then consider two MDM waveguide based slow light systems: a MDM waveguide side-coupled to arrays of stub resonators system and a MDM waveguide side-coupled to arrays of double-stub resonators system. We find that, as the group velocity decreases, the sensitivity of the effective index of the waveguide mode to variations of the refractive index of the fluid filling the sensors as well as the sensitivities of the reflection and transmission coefficients of the waveguide mode increase. The sensing characteristics of the slow-light waveguide based sensor structures are systematically analyzed. We show that the slow-light enhanced sensors lead to not only 3.9 and 3.5 times enhancements in the refractive index sensitivity, and therefore in the minimum detectable refractive index change, but also to 2 and 3 times reductions in the required sensing length, respectively, compared to a sensor using a MDM waveguide with small width structure.

  18. Fluorescence Spectroscopy with Metal-Dielectric Waveguides. (United States)

    Badugu, Ramachandram; Szmacinski, Henryk; Ray, Krishanu; Descrovi, Emiliano; Ricciardi, Serena; Zhang, Douguo; Chen, Junxue; Huo, Yiping; Lakowicz, Joseph R


    We describe a hybrid metal-dielectric waveguide structures (MDWs) with numerous potential applications in the biosciences. These structures consist of a thin metal film coated with a dielectric layer. Depending on the thickness of the dielectric layer, the modes can be localized near the metal, within the dielectric, or at the top surface of the dielectric. The optical modes in a metal-dielectric waveguide can have either S (TE) or P (TM) polarization. The dielectric spacer avoids the quenching, which usually occurs for fluorophores within about 5 nm from the metal. Additionally, the resonances display a sharp angular dependence and can exhibit several hundred-fold increases in intensity (E2) at the silica-air interface relative to the incident intensity. Fluorophores placed on top of the silica layer couple efficiently with the metal, resulting in a sharp angular distribution of emission through the metal and down from the bottom of the structure. This coupling occurs over large distances to several hundred nm away from the metal and was found to be consistent with simulations of the reflectivity of the metal-dielectric waveguides. Remarkably, for some silica thicknesses, the emission is almost completely coupled through the structure with little free-space emission away from the metal-dielectric waveguide. The efficiency of fluorophore coupling is related to the quality of the resonant modes sustained by the metal-dielectric waveguide, resulting in coupling of most of the emission through the metal into the underlying glass substrates. Metal-dielectric waveguides also provide a method to resolve the emission from surface-bound fluorophores from the bulk-phase fluorophores. Metal-dielectric waveguides are simple to fabricate for large surface areas, the resonance wavelength can be adjusted by the dielectric thickness, and the silica surface is suitable for coupling to biomolecules. Metal-dielectric waveguides can have numerous applications in diagnostics and high

  19. Coplanar Waveguide Radial Line Double Stub and Application to Filter Circuits (United States)

    Simons, R. N.; Taub, S. R.


    Coplanar waveguide (CPW) and grounded coplanar waveguide (GCPW) radial line double stub resonators are experimentally characterized with respect to stub radius and sector angle. A simple closed-form design equation, which predicts the resonance radius of the stub, is presented. Use of a double stub resonator as a lowpass filter or as a harmonic suppression filter is demonstrated, and design rules are given.

  20. Waveguide-Based Biosensors for Pathogen Detection

    Directory of Open Access Journals (Sweden)

    Nile Hartman


    Full Text Available Optical phenomena such as fluorescence, phosphorescence, polarization, interference and non-linearity have been extensively used for biosensing applications. Optical waveguides (both planar and fiber-optic are comprised of a material with high permittivity/high refractive index surrounded on all sides by materials with lower refractive indices, such as a substrate and the media to be sensed. This arrangement allows coupled light to propagate through the high refractive index waveguide by total internal reflection and generates an electromagnetic wave—the evanescent field—whose amplitude decreases exponentially as the distance from the surface increases. Excitation of fluorophores within the evanescent wave allows for sensitive detection while minimizing background fluorescence from complex, “dirty” biological samples. In this review, we will describe the basic principles, advantages and disadvantages of planar optical waveguide-based biodetection technologies. This discussion will include already commercialized technologies (e.g., Corning’s EPIC® Ô, SRU Biosystems’ BIND™, Zeptosense®, etc. and new technologies that are under research and development. We will also review differing assay approaches for the detection of various biomolecules, as well as the thin-film coatings that are often required for waveguide functionalization and effective detection. Finally, we will discuss reverse-symmetry waveguides, resonant waveguide grating sensors and metal-clad leaky waveguides as alternative signal transducers in optical biosensing.

  1. Phonon engineering in proximity enhanced superconductor heterostructures. (United States)

    Tang, Yong-Chao; Kwon, Sangil; Mohebbi, Hamid R; Cory, David G; Miao, Guo-Xing


    In this research, we tailor the phonon density of states (DOS) in thin superconducting films to suppress quasiparticle losses. We examine a model system of a proximity-enhanced three-layered Al/Nb/Al heterostructure and show that the local quantized phonon spectrum of the ultrathin Al cladding layers in the heterostructure has a pronounced effect on the superconducting resonator's quality factors. Instead of a monotonic increase of quality factors with decreasing temperatures, we observe the quality factor reaches a maximum at 1.2 K in 5/50/5 nm Al/Nb/Al microstrip resonators, because of a quantized phonon ladder. The phonon DOS may be engineered to enhance the performance of quantum devices.

  2. Microfabricated Waveguide Atom Traps.

    Energy Technology Data Exchange (ETDEWEB)

    Jau, Yuan-Yu [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)


    A nanoscale , microfabricated waveguide structure can in - principle be used to trap atoms in well - defined locations and enable strong photon-atom interactions . A neutral - atom platform based on this microfabrication technology will be prealigned , which is especially important for quantum - control applications. At present, there is still no reported demonstration of evanescent - field atom trapping using a microfabricated waveguide structure. We described the capabilities established by our team for future development of the waveguide atom - trapping technology at SNL and report our studies to overcome the technical challenges of loading cold atoms into the waveguide atom traps, efficient and broadband optical coupling to a waveguide, and the waveguide material for high - power optical transmission. From the atomic - physics and the waveguide modeling, w e have shown that a square nano-waveguide can be utilized t o achieve better atomic spin squeezing than using a nanofiber for first time.

  3. Near-infrared characterization of gallium nitride photonic-crystal waveguides and cavities. (United States)

    Dharanipathy, U; Vico Triviño, N; Yan, C; Diao, Z; Carlin, J-F; Grandjean, N; Houdré, R


    We report the design and optical characterization of fully suspended wire waveguides and photonic crystal (PhC) membranes fabricated on a gallium nitride layer grown on silicon substrate operating at 1.5 μm. W1-type PhC waveguides are coupled with suspended wires and are investigated using a standard end-fire setup. The experimental and theoretical dispersion properties of the propagating modes in the wires and photonic-crystal waveguides are shown. Modified L3 cavities with quality factors of up to 2200 and heterostructure cavities with quality factors of up to 5400 are experimentally demonstrated.

  4. Heterostructures and quantum devices

    CERN Document Server

    Einspruch, Norman G


    Heterostructure and quantum-mechanical devices promise significant improvement in the performance of electronic and optoelectronic integrated circuits (ICs). Though these devices are the subject of a vigorous research effort, the current literature is often either highly technical or narrowly focused. This book presents heterostructure and quantum devices to the nonspecialist, especially electrical engineers working with high-performance semiconductor devices. It focuses on a broad base of technical applications using semiconductor physics theory to develop the next generation of electrical en

  5. Plasmon resonant cavities in vertical nanowire arrays

    Energy Technology Data Exchange (ETDEWEB)

    Bora, M; Bond, T; Behymer, E; Chang, A


    We investigate tunable plasmon resonant cavity arrays in paired parallel nanowire waveguides. Resonances are observed when the waveguide length is an odd multiple of quarter plasmon wavelengths, consistent with boundary conditions of node and antinode at the ends. Two nanowire waveguides satisfy the dispersion relation of a planar metal-dielectric-metal waveguide of equivalent width equal to the square field average weighted gap. Confinement factors over 103 are possible due to plasmon focusing in the inter-wire space.

  6. Integration of carbon nanotubes in slot waveguides (Conference Presentation) (United States)

    Durán-Valdeiglesias, Elena; Zhang, Weiwei; Hoang, Thi Hong Cam; Alonso-Ramos, Carlos; Serna, Samuel; Le Roux, Xavier; Cassan, Eric; Balestrieri, Matteo; Keita, Al-Saleh; Sarti, Francesco; Biccari, Francesco; Torrini, Ughetta; Vinattieri, Anna; Yang, Hongliu; Bezugly, Viktor; Cuniberti, Gianaurelio; Filoramo, Arianna; Gurioli, Massimo; Vivien, Laurent


    Demanding applications such as video streaming, social networking, or web search relay on a large network of data centres, interconnected through optical links. The ever-growing data rates and power consumption inside these data centres are pushing copper links close to their fundamental limits. Optical interconnects are being extensively studied with the purpose of solving these limitations. Among the different possible technology platforms, silicon photonics, due to its compatibility with the CMOS platform, has become one of the preferred solutions for the development of the future generation photonic interconnects. However, the on-chip integration of all photonic and optoelectronic building blocks (sources, modulators and detectors…) is very complex and is not cost-effective due to the various materials involved (Ge for detection, doped Si for modulators and III-V for lasing). Carbon nanotubes (CNTs) are nanomaterials of great interest in photonics thanks to their fundamental optical properties, including near-IR room-temperature foto- and electro- luminescence, Stark effect, Kerr effect and absorption. In consequence, CNTs have the ability to emit, modulate and detect light in the telecommunications wavelength range. Furthermore, they are being extensively developed for new nano-electronics applications. In this work, we propose to use CNTs as active material integrated into silicon photonics for the development of all optoelectronic devices. Here, we report on the development of new integration schemes to couple the light emission from CNTs into optical resonators implemented on the silicon-on-insulator and silicon-nitride-on-insulator platforms. A theoretical and experimental analysis of the light interaction of CNTs with micro-ring resonators based on strip and slot waveguides and slot photonic crystal heterostructure cavities were carried out.

  7. Electron Waveguide Y-branch Switches Controlled by Pt/GaAs Schottky Gates (United States)

    Forsberg, E.; Hieke, K.

    Electron waveguide Y-branch switches have been fabricated in a GaAs/AlGaAs heterostructure. These are controlled by Pt/GaAs Schottky contacts, which were realized by an in-situ electrochemical process. In this paper we describe the fabrication process as well as present results from conductance measurements in the fabricated devices.

  8. Silicon photonics waveguide array chemical sensor with integrated read-out (Conference Presentation) (United States)

    Janeiro, Ricardo; Flores, Raquel; Viegas, Jaime


    Chemical sensing is usually achieved in photonics platforms by monitoring spectral changes on the output of a passive photonic element due to the modulation of the refractive index of core and cladding. Therefore, compact interferometers are usually sought for the embodiment of refractometer sensors. We present our work on refractive index sensors based on arrayed waveguide interference, which are built on a Silicon-On-Insulator (SOI) platform. A comparative study of two configurations, resonant and non-resonant is presented. In both cases the main design is based on a set of closely placed single mode waveguides. The distance between waveguides is such that directional coupling occurs. Moreover, when the distance between the waveguides is small comparatively to the transversal exponential decay length of the eigenmode of the waveguide, there is an enhancement effect of the electric field in the region between the waveguides, as usually seen for slotted waveguides. The reported sensors include multiple parallel slotted waveguides which are the core of the sensor. Non-resonant configuration incorporates straight waveguides from which the output can be directly imaged onto a CCD array for direct sensor read-out, while the resonant layout presents a set of concentric racetrack waveguides designed for light extended lifetime, enhancing the sensor sensitivity. A top polymer cladding is used to encapsulate the waveguides providing a permeable low index material. This cladding material acts as the transducer element, changing its optical properties when in contact with a chemical of interest, therefore allowing for high sensitivity and chemical selectivity.

  9. Deep-probe metal-clad waveguide biosensors

    DEFF Research Database (Denmark)

    Skivesen, Nina; Horvath, Robert; Thinggaard, S.


    Two types of metal-clad waveguide biosensors, so-called dip-type and peak-type, are analyzed and tested. Their performances are benchmarked against the well-known surface-plasmon resonance biosensor, showing improved probe characteristics for adlayer thicknesses above 150-200 nm. The dip-type metal......-clad waveguide sensor is shown to be the best all-round alternative to the surface-plasmon resonance biosensor. Both metal-clad waveguides are tested experimentally for cell detection, showing a detection linut of 8-9 cells/mm(2). (c) 2006 Elsevier B.V. All rights reserved....

  10. High power, 1060-nm diode laser with an asymmetric hetero-waveguide

    Energy Technology Data Exchange (ETDEWEB)

    Li, T; Zhang, Yu [National Key Lab. On High Power Diode Laser,Changchun University of Science and Technology,Changchun, 130033 (China); Hao, E [College of Physics, Jilin University, Changchun, 130021 (China)


    By introducing an asymmetric hetero-waveguide into the epitaxial structure of a diode laser, a 6.21-W output is achieved at a wavelength of 1060 nm. A different design in p- and n-confinement, based on optimisation of energy bands, is used to reduce voltage loss and meet the requirement of high power and high wall-plug efficiency. A 1060-nm diode laser with a single quantum well and asymmetric hetero-structure waveguide is fabricated and analysed. Measurement results show that the asymmetric hetero-structure waveguide can be efficiently used for reducing voltage loss and improving the confinement of injection carriers and wall-plug efficiency. (lasers)

  11. Interconnect Between a Waveguide and a Dielectric Waveguide Comprising an Impedance Matched Dielectric Lens (United States)

    Decrossas, Emmanuel (Inventor); Chattopadhyay, Goutam (Inventor); Chahat, Nacer (Inventor); Tang, Adrian J. (Inventor)


    A lens for interconnecting a metallic waveguide with a dielectric waveguide is provided. The lens may be coupled a metallic waveguide and a dielectric waveguide, and minimize a signal loss between the metallic waveguide and the dielectric waveguide.

  12. Graphene antidot lattice waveguides

    DEFF Research Database (Denmark)

    Pedersen, Jesper Goor; Gunst, Tue; Markussen, Troels


    We introduce graphene antidot lattice waveguides: nanostructured graphene where a region of pristine graphene is sandwiched between regions of graphene antidot lattices. The band gaps in the surrounding antidot lattices enable localized states to emerge in the central waveguide region. We model...... the waveguides via a position-dependent mass term in the Dirac approximation of graphene and arrive at analytical results for the dispersion relation and spinor eigenstates of the localized waveguide modes. To include atomistic details we also use a tight-binding model, which is in excellent agreement...... with the analytical results. The waveguides resemble graphene nanoribbons, but without the particular properties of ribbons that emerge due to the details of the edge. We show that electrons can be guided through kinks without additional resistance and that transport through the waveguides is robust against...

  13. Novel concepts for terahertz waveguide spectroscopy

    DEFF Research Database (Denmark)

    Jepsen, Peter Uhd


    . With such waveguides we demonstrate that it is possible to perform quantitative spectroscopy on very small volumes of sample material inside the PPWG. Using continuous-wave as well as femtosecond excitation we inject carriers into semiconductor material in the transparent PPWG, and perform static as well as transient...... spectroscopy of the optically injected charges. Ongoing work in our laboratory investigates the lower limits to the amount of sample material required for quantitative spectroscopy. Whereas sensing of extremely small quantities of material is possible with resonant and thus narrow-band THz waveguide techniques...

  14. Scaling down the two-dimensional electron gas spin resonance (ESR) phenomena in GaAs/AlGaAs heterostructures to sub-micron samples (United States)

    Bandaru, Prabhakar; Yablonovitch, Eli; Jiang, Hong-Wen


    Electron Spin Resonance (ESR) has been proposed as a technique for achieving single electron and subsequently single spin control, important for the emerging fields of spintronics and quantum computing. In this paper, we report on ESR in the quantum Hall regime, of sub-micron structures containing a few hundred electrons. These phenomena are contrasted with ESR phenomena in structures containing 10^7 - 10^9 electrons, which have been performed so far (Reference 1). There are several novel features observed in the ESR of small structures, such as a very large decrease of resistance and shift in the quantum Hall minima to lower magnetic fields after the resonance. These imply a reduction in the number of electrons and could result from the greater influence of the surface and impurity potential fluctuations intrinsic to a small sample. The ESR peak intensity is hypothesized to result from the transfer of electrons from the localized states to the extended states. References: 1.H.W.Jiang and E. Yablonovitch, Phys. Rev.B., 64, R041307, (2001) 2.M.Dobers, K.v. Klitzing and G. Weimann,Phys. Rev. B, 38, 5453, (1988).

  15. Novel low-loss waveguide delay lines using Vernier ring resonators for on-chip multi-λ microwave photonic signal processors

    NARCIS (Netherlands)

    Zhuang, L.; Hoekman, M.; Beeker, Willem; Leinse, Arne; Heideman, Rene; van Dijk, Paulus; Roeloffzen, C.G.H.


    In this paper, novel photonic delay lines (DLs) using Vernier/non-identical ring resonators (VRRs) are proposed and demonstrated, which are capable of simultaneous generation of multiple different delays at different wavelengths (frequencies). The simple device architectures and full

  16. Resonance

    DEFF Research Database (Denmark)

    Petersen, Nils Holger


    A chapter in a book about terminology within the field of medievalism: the chapter discusses the resonance of medieval music and ritual in modern (classical) music culture and liturgical practice.......A chapter in a book about terminology within the field of medievalism: the chapter discusses the resonance of medieval music and ritual in modern (classical) music culture and liturgical practice....

  17. Multiple Critical Couplings and Sensing in a Microresonator-Waveguide System (United States)

    Acharyya, Nirmalendu; Kozyreff, Gregory


    We study the optical transmission of a waveguide that is side coupled to a high-Q circular microresonator. The coupling is critical if the intrinsic resonator losses equal the coupling losses to the waveguide. When this happens, the transmittance of the waveguide displays resonance dips with maximal depth as the frequency is swept through the resonators' resonances. We show that multiple configurations, parametrized by the minimal distance between the resonator and the waveguide, can lead to critical coupling. Indeed, for a sufficiently large resonator radius, the flow of power between the waveguide and the resonator can change sign several times within a single pass. This leads to an oscillatory coupling parameter as a function of the separation distance. As a result, multiple geometrical configurations can lead to critical coupling, even if the waveguide lies in the equatorial plane of the resonator. These results are explained using coupled-mode theory and full-wave numerical simulations. In the vicinity of secondary or higher-order critical coupling, the depth of the transmittance dip is very sensitive to the environment. We discuss how this effect can be exploited for sensing purpose. Alternatively, by actively controlling the environment in the secondary critical configuration, the waveguide-resonator system can be driven as an optical switch.

  18. Modeling of Slot Waveguide Sensors Based on Polymeric Materials

    Directory of Open Access Journals (Sweden)

    Lorenzo Pavesi


    Full Text Available Slot waveguides are very promising for optical sensing applications because of their peculiar spatial mode profile. In this paper we have carried out a detailed analysis of mode confinement properties in slot waveguides realized in very low refractive index materials. We show that the sensitivity of a slot waveguide is not directly related to the refractive index contrast of high and low materials forming the waveguide. Thus, a careful design of the structures allows the realization of high sensitivity devices even in very low refractive index materials (e.g., polymers to be achieved. Advantages of low index dielectrics in terms of cost, functionalization and ease of fabrication are discussed while keeping both CMOS compatibility and integrable design schemes. Finally, applications of low index slot waveguides as substitute of bulky fiber capillary sensors or in ring resonator architectures are addressed. Theoretical results of this work are relevant to well established polymer technologies.

  19. Modeling of Slot Waveguide Sensors Based on Polymeric Materials (United States)

    Bettotti, Paolo; Pitanti, Alessandro; Rigo, Eveline; De Leonardis, Francesco; Passaro, Vittorio M. N.; Pavesi, Lorenzo


    Slot waveguides are very promising for optical sensing applications because of their peculiar spatial mode profile. In this paper we have carried out a detailed analysis of mode confinement properties in slot waveguides realized in very low refractive index materials. We show that the sensitivity of a slot waveguide is not directly related to the refractive index contrast of high and low materials forming the waveguide. Thus, a careful design of the structures allows the realization of high sensitivity devices even in very low refractive index materials (e.g., polymers) to be achieved. Advantages of low index dielectrics in terms of cost, functionalization and ease of fabrication are discussed while keeping both CMOS compatibility and integrable design schemes. Finally, applications of low index slot waveguides as substitute of bulky fiber capillary sensors or in ring resonator architectures are addressed. Theoretical results of this work are relevant to well established polymer technologies. PMID:22164020

  20. Tailorable Stimulated Brillouin Scattering in Nanoscale Silicon Waveguides

    CERN Document Server

    Shin, Heedeuk; Jarecki, Robert; Cox, Jonathan A; Olsson, Roy H; Starbuck, Andrew; Wang, Zheng; Rakich, Peter T


    While nanoscale modal confinement radically enhances a variety of nonlinear light-matter interactions within silicon waveguides, traveling-wave stimulated Brillouin scattering nonlinearities have never been observed in silicon nanophotonics. Through a new class of hybrid photonic-phononic waveguides, we demonstrate tailorable traveling-wave forward stimulated Brillouin scattering in nanophotonic silicon waveguides for the first time, yielding 3000 times stronger forward SBS responses than any previous waveguide system. Simulations reveal that a coherent combination of electrostrictive forces and radiation pressures are responsible for greatly enhanced photon-phonon coupling at nano-scales. Highly tailorable Brillouin nonlinearities are produced by engineering the structure of a membrane-suspended waveguide to yield Brillouin resonances from 1 to 18 GHz through high quality-factor (>1000) phonon modes. Such wideband and tailorable stimulated Brillouin scattering in silicon photonics could enable practical real...

  1. Resonances

    DEFF Research Database (Denmark)

    an impetus or drive to that account: change, innovation, rupture, or discontinuity. Resonances: Historical Essays on Continuity and Change explores the historiographical question of the modes of interrelation between these motifs in historical narratives. The essays in the collection attempt to realize...... theoretical consciousness through historical narrative ‘in practice’, by discussing selected historical topics from Western cultural history, within the disciplines of history, literature, visual arts, musicology, archaeology, philosophy, and theology. The title Resonances indicates the overall perspective...... of the book: how connotations of past meanings may resonate through time, in new contexts, assuming new meanings without surrendering the old....

  2. Dielectric Waveguide lasers

    NARCIS (Netherlands)

    Pollnau, Markus; Orlovic, V.A.; Pachenko, V.; Scherbakov, I.A.


    Our recent results on planar and channel waveguide fabrication and lasers in the dielectric oxide materials Ti:sapphire and rare-earth-ion-doped potassium yttrium double tungstate (KYW) are reviewed. We have employed waveguide fabrication methods such as liquid phase epitaxy and reactive ion etching

  3. Voltage control of magnetism in multiferroic heterostructures. (United States)

    Liu, Ming; Sun, Nian X


    Electrical tuning of magnetism is of great fundamental and technical importance for fast, compact and ultra-low power electronic devices. Multiferroics, simultaneously exhibiting ferroelectricity and ferromagnetism, have attracted much interest owing to the capability of controlling magnetism by an electric field through magnetoelectric (ME) coupling. In particular, strong strain-mediated ME interaction observed in layered multiferroic heterostructures makes it practically possible for realizing electrically reconfigurable microwave devices, ultra-low power electronics and magnetoelectric random access memories (MERAMs). In this review, we demonstrate this remarkable E-field manipulation of magnetism in various multiferroic composite systems, aiming at the creation of novel compact, lightweight, energy-efficient and tunable electronic and microwave devices. First of all, tunable microwave devices are demonstrated based on ferrite/ferroelectric and magnetic-metal/ferroelectric composites, showing giant ferromagnetic resonance (FMR) tunability with narrow FMR linewidth. Then, E-field manipulation of magnetoresistance in multiferroic anisotropic magnetoresistance and giant magnetoresistance devices for achieving low-power electronic devices is discussed. Finally, E-field control of exchange-bias and deterministic magnetization switching is demonstrated in exchange-coupled antiferromagnetic/ferromagnetic/ferroelectric multiferroic hetero-structures at room temperature, indicating an important step towards MERAMs. In addition, recent progress in electrically non-volatile tuning of magnetic states is also presented. These tunable multiferroic heterostructures and devices provide great opportunities for next-generation reconfigurable radio frequency/microwave communication systems and radars, spintronics, sensors and memories.

  4. Waveguide-based terahertz metamaterial functional components (United States)

    Wang, Z. G.; Zhou, Y. Q.; Yang, L. M.; Gong, Cheng


    We suggest a flexible platform based on waveguides for constructing metamaterial functional components which work in the terahertz waveband. The properties of the components can be changed by selecting the specified metamaterial resonance structures on the waveguide’s narrow wall. In the paper, metallic circular patches are used as resonance structures to design the functional component which can be configured as a filter or absorber. The simulation and experimental results demonstrate that the component’s attenuation and absorption bandwidth can be configured by changing the quantities and sizes of the resonance structures.

  5. Fluorophore-doped xerogel antiresonant reflecting optical waveguides. (United States)

    Llobera, A; Cadarso, V J; Carregal-Romero, E; Brugger, J; Domínguez, C; Fernández-Sánchez, C


    Rhodamine B and Alexa Fluor 430 fluorophores have been used as doping agents for xerogel waveguides defined over an antiresonant (ARROW) filter. This configuration has a significant level of integration, since it merges the waveguide, the light emitter and the filter in a single photonic element. Different technologies have been combined for their implementation, namely soft lithography, standard silicon-based technology and silicon bulk micromachining. The spectral response of 15-mm long waveguides without fluorophore is first analyzed as a function of the waveguide width. Here, it has been observed how the xerogel used has a high transparency in the visible spectra, having only significant absorption at the wavelength where the ARROW filter is in resonance. In a second step, identical waveguides but doped with two different concentrations of Rhodamine B and Alexa Fluor 430 are studied. In addition to the effect of the filter, fluorophore-doped xerogel waveguides show losses close to -2 dB (equivalent to 2 dB of light emission). In addition, it has been observed how an increase of the fluorophore concentration within the xerogel matrix does not provide with a emission increase, but saturation or even a decrease of this magnitude due to self-absorption. Finally, the total losses of the proposed waveguides are analyzed as a function of their width, obtaining losses close to 5 dB for waveguide widths higher than 50 µm.

  6. A porous silicon Bragg grating waveguide by direct laser writing

    Energy Technology Data Exchange (ETDEWEB)

    Rea, Ilaria; Iodice, Mario; Coppola, Giuseppe; Rendina, Ivo; De Stefano, Luca [National Council of Research, Institute for Microelectronic and Microsystems, Department of Naples, Via P Castellino 111, I-80131 Naples (Italy); Marino, Antigone [Department of Physics, ' Federico II' University of Naples, Via Cinthia, I-80126 Naples (Italy)], E-mail:


    We have designed, fabricated and characterized a porous silicon-based Bragg grating integrated in an optical waveguide, by using a low cost and fast technique, direct laser writing. A periodic optical structure with a pitch of 10 {mu}m, resonant in the near-infrared wavelength region, has been obtained. The simulated transmission spectra, calculated by the transfer matrix method and waveguide modal computation, are in good qualitative agreement with the experimental ones. The waveguide transmission losses have been quantified as 22 dB cm{sup -1}.


    Indian Academy of Sciences (India)

    Nuclear magnetic resonance (NMR) is a mani- festation of an intrinsic property of the nucleus, i.e. nuclear spin angular momen- tum. Spin angular momentum gives rise to magnetic moments. Thus, nuclei that pos- sess net magnetic moments behave like very small bar magnets. NMR spectroscopy in- volves the study of the ...

  8. Active Photonic Crystal Waveguides

    DEFF Research Database (Denmark)

    Ek, Sara

    due to photonic crystal dispersion. The observations are explained by the enhancement of net gain by light slow down. Another application based on active photonic crystal waveguides is micro lasers. Measurements on quantum dot micro laser cavities with different mirror configurations and photonic......This thesis deals with the fabrication and characterization of active photonic crystal waveguides, realized in III-V semiconductor material with embedded active layers. The platform offering active photonic crystal waveguides has many potential applications. One of these is a compact photonic...... crystal semiconductor optical amplier. As a step towards such a component, photonic crystal waveguides with a single quantum well, 10 quantum wells and three layers of quantum dots are fabricated and characterized. An experimental study of the amplied spontaneous emission and a implied transmission...

  9. Microfabricated bragg waveguide (United States)

    Fleming, James G.; Lin, Shawn-Yu; Hadley, G. Ronald


    A microfabricated Bragg waveguide of semiconductor-compatible material having a hollow core and a multilayer dielectric cladding can be fabricated by integrated circuit technologies. The microfabricated Bragg waveguide can comprise a hollow channel waveguide or a hollow fiber. The Bragg fiber can be fabricated by coating a sacrificial mandrel or mold with alternating layers of high- and low-refractive-index dielectric materials and then removing the mandrel or mold to leave a hollow tube with a multilayer dielectric cladding. The Bragg channel waveguide can be fabricated by forming a trench embedded in a substrate and coating the inner wall of the trench with a multilayer dielectric cladding. The thicknesses of the alternating layers can be selected to satisfy the condition for minimum radiation loss of the guided wave.


    Directory of Open Access Journals (Sweden)



    Full Text Available The hollow core photonic crystal waveguide biosensor is designed and described. The biosensor was tested in experiments for artificial sweetener identification in drinks. The photonic crystal waveguide biosensor has a high sensitivity to the optical properties of liquids filling up the hollow core. The compactness, good integration ability to different optical systems and compatibility for use in industrial settings make such biosensor very promising for various biomedical applications.

  11. Peptide Optical waveguides. (United States)

    Handelman, Amir; Apter, Boris; Shostak, Tamar; Rosenman, Gil


    Small-scale optical devices, designed and fabricated onto one dielectric substrate, create integrated optical chip like their microelectronic analogues. These photonic circuits, based on diverse physical phenomena such as light-matter interaction, propagation of electromagnetic waves in a thin dielectric material, nonlinear and electro-optical effects, allow transmission, distribution, modulation, and processing of optical signals in optical communication systems, chemical and biological sensors, and more. The key component of these optical circuits providing both optical processing and photonic interconnections is light waveguides. Optical confinement and transmitting of the optical waves inside the waveguide material are possible due to the higher refractive index of the waveguides in comparison with their surroundings. In this work, we propose a novel field of bionanophotonics based on a new concept of optical waveguiding in synthetic elongated peptide nanostructures composed of ordered peptide dipole biomolecules. New technology of controllable deposition of peptide optical waveguiding structures by nanofountain pen technique is developed. Experimental studies of refractive index, optical transparency, and linear and nonlinear waveguiding in out-of-plane and in-plane diphenylalanine peptide nanotubes have been conducted. Optical waveguiding phenomena in peptide structures are simulated by the finite difference time domain method. The advantages of this new class of bio-optical waveguides are high refractive index contrast, wide spectral range of optical transparency, large optical nonlinearity, and electro-optical effect, making them promising for new applications in integrated multifunctional photonic circuits. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.

  12. Exact equivalent straight waveguide model for bent and twisted waveguides

    DEFF Research Database (Denmark)

    Shyroki, Dzmitry


    Exact equivalent straight waveguide representation is given for a waveguide of arbitrary curvature and torsion. No assumptions regarding refractive index contrast, isotropy of materials, or particular morphology in the waveguide cross section are made. This enables rigorous full-vector modeling o...

  13. Gap Surface Plasmon Waveguide Analysis

    DEFF Research Database (Denmark)

    Nielsen, Michael Grøndahl; Bozhevolnyi, Sergey I.


    Plasmonic waveguides supporting gap surface plasmons (GSPs) localized in a dielectric spacer between metal films are investigated numerically and the waveguiding properties at telecommunication wavelengths are presented. Especially, we emphasize that the mode confinement can advantageously be con...

  14. Nanoporous polymer liquid core waveguides

    DEFF Research Database (Denmark)

    Gopalakrishnan, Nimi; Christiansen, Mads Brøkner; Ndoni, Sokol


    We demonstrate liquid core waveguides defined by UV to enable selective water infiltration in nanoporous polymers, creating an effective refractive index shift Δn=0.13. The mode confinement and propagation loss in these waveguides are presented.......We demonstrate liquid core waveguides defined by UV to enable selective water infiltration in nanoporous polymers, creating an effective refractive index shift Δn=0.13. The mode confinement and propagation loss in these waveguides are presented....

  15. Slab waveguide with air core layer and anisotropic left-handed material claddings as a sensor

    National Research Council Canada - National Science Library

    Taya, S A


    .... Different from the waveguide mode sensors and surface plasmon resonance sensors in which the analyte is placed in the evanescent field region, the proposed sensor contains the sample in the core...

  16. Analysis of oversized sliding waveguide by mode matching and multi-mode network theory

    Energy Technology Data Exchange (ETDEWEB)

    Ohkubo, K.; Kubo, S.; Idei, H.; Shimozuma, T.; Yoshimura, Y.; Sato, M.; Takita, Y. [National Inst. for Fusion Science, Toki, Gifu (Japan); Leuterer, F. [Max-Planck Institut fuer Plasmaphysik, Garching (Germany)


    Transmission and reflection coefficients of HE{sub 11} hybrid modes in the sliding waveguide are discussed on the basis of mode matching method and multi-mode network theory. The sliding waveguide is composed of the corrugated waveguide with 88.9 mm{phi} and the smooth-wall waveguide with 110 mm{phi} in inner diameter. It is confirmed that the decrease in power of <0.2% at 84 GHz is obtained for 2 cm in gap of the sliding waveguide. At the sliding length near multi-half-wavelength in vacuum, transmission and reflection powers in the sliding waveguide change slightly, because the very small amount of standing wave of higher-order TE or TM modes is produced resonantly. (author)

  17. Waveguides for walking droplets

    CERN Document Server

    Filoux, Boris; Schlagheck, Peter; Vandewalle, Nicolas


    When gently placing a droplet onto a vertically vibrated bath, a drop can bounce permanently. Upon increasing the forcing acceleration, the droplet is propelled by the wave it generates and becomes a walker with a well defined speed. We investigate the confinement of a walker in different rectangular cavities, used as waveguides for the Faraday waves emitted by successive droplet bounces. By studying the walker velocities, we discover that 1d confinement is optimal for narrow channels. We also propose an analogy with waveguide models based on the observation of the Faraday instability within the channels.

  18. Distributed meandering waveguides (DMWs) for novel photonic circuits (Conference Presentation) (United States)

    Dag, Ceren B.; Anil, Mehmet Ali; Serpengüzel, Ali


    Meandering waveguide distributed feedback structures are novel integrated photonic lightwave and microwave circuit elements. Meandering waveguide distributed feedback structures with a variety of spectral responses can be designed for a variety of lightwave and microwave circuit element functions. Distributed meandering waveguide (DMW) structures [1] show a variety of spectral behaviors with respect to the number of meandering loop mirrors (MLMs) [2] used in their composition as well as their internal coupling constants (Cs). DMW spectral behaviors include Fano resonances, coupled resonator induced transparency (CRIT), notch, add-drop, comb, and hitless filters. What makes the DMW special is the self-coupling property intrinsic to the DMW's nature. The basic example of DMW's nature is motivated through the analogy between the so-called symmetric meandering resonator (SMR), which consists of two coupled MLMs, and the resonator enhanced Mach-Zehnder interferometer (REMZI) [3]. A SMR shows the same spectral characteristics of Fano resonances with its self-coupling property, similar to the single, distributed and binary self coupled optical waveguide (SCOW) resonators [4]. So far DMWs have been studied for their electric field intensity, phase [5] and phasor responses [6]. The spectral analysis is performed using the coupled electric field analysis and the generalization of single meandering loop mirrors to multiple meandering distributed feedback structures is performed with the transfer matrix method. The building block of the meandering waveguide structures, the meandering loop mirror (MLM), is the integrated analogue of the fiber optic loop mirrors. The meandering resonator (MR) is composed of two uncoupled MLM's. The meandering distributed feedback (MDFB) structure is the DFB of the MLM. The symmetric MR (SMR) is composed of two coupled MLM's, and has the characteristics of a Fano resonator in the general case, and tunable power divider or tunable hitless filter

  19. Quantum Nonlinear Optics with a Germanium-Vacancy Color Center in a Nanoscale Diamond Waveguide (United States)

    Bhaskar, M. K.; Sukachev, D. D.; Sipahigil, A.; Evans, R. E.; Burek, M. J.; Nguyen, C. T.; Rogers, L. J.; Siyushev, P.; Metsch, M. H.; Park, H.; Jelezko, F.; Lončar, M.; Lukin, M. D.


    We demonstrate a quantum nanophotonics platform based on germanium-vacancy (GeV) color centers in fiber-coupled diamond nanophotonic waveguides. We show that GeV optical transitions have a high quantum efficiency and are nearly lifetime broadened in such nanophotonic structures. These properties yield an efficient interface between waveguide photons and a single GeV center without the use of a cavity or slow-light waveguide. As a result, a single GeV center reduces waveguide transmission by 18 ±1 % on resonance in a single pass. We use a nanophotonic interferometer to perform homodyne detection of GeV resonance fluorescence. By probing the photon statistics of the output field, we demonstrate that the GeV-waveguide system is nonlinear at the single-photon level.

  20. Quantum Nonlinear Optics with a Germanium-Vacancy Color Center in a Nanoscale Diamond Waveguide. (United States)

    Bhaskar, M K; Sukachev, D D; Sipahigil, A; Evans, R E; Burek, M J; Nguyen, C T; Rogers, L J; Siyushev, P; Metsch, M H; Park, H; Jelezko, F; Lončar, M; Lukin, M D


    We demonstrate a quantum nanophotonics platform based on germanium-vacancy (GeV) color centers in fiber-coupled diamond nanophotonic waveguides. We show that GeV optical transitions have a high quantum efficiency and are nearly lifetime broadened in such nanophotonic structures. These properties yield an efficient interface between waveguide photons and a single GeV center without the use of a cavity or slow-light waveguide. As a result, a single GeV center reduces waveguide transmission by 18±1% on resonance in a single pass. We use a nanophotonic interferometer to perform homodyne detection of GeV resonance fluorescence. By probing the photon statistics of the output field, we demonstrate that the GeV-waveguide system is nonlinear at the single-photon level.

  1. Progress in planar optical waveguides

    CERN Document Server

    Wang, Xianping; Cao, Zhuangqi


    This book provides a comprehensive description of various slab waveguide structures ranged from graded-index waveguide to symmetrical metal-cladding waveguide. In this book, the transfer Matrix method is developed and applied to analyze the simplest case and the complex generalizations. A novel symmetrical metal-cladding waveguide structure is proposed and systematically investigated for several issues of interest, such as biochemical sensing, Goos-Hänchen shift and the slow light effect, etc. Besides, this book summarizes the authors’ research works on waveguides over the last decade. The readers who are familiar with basic optics theory may find this book easy to read and rather inspiring.

  2. Waveguide-Coupled Superconducting Nanowire Single-Photon Detectors (United States)

    Beyer, Andrew D.; Briggs, Ryan M.; Marsili, Francesco; Cohen, Justin D.; Meenehan, Sean M.; Painter, Oskar J.; Shaw, Matthew D.


    We have demonstrated WSi-based superconducting nanowire single-photon detectors coupled to SiNx waveguides with integrated ring resonators. This photonics platform enables the implementation of robust and efficient photon-counting detectors with fine spectral resolution near 1550 nm.

  3. Enhanced optical nonlinearities in the near-infrared using III-nitride heterostructures coupled to metamaterials

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, Omri, E-mail:, E-mail:; Ma, Xuedan; Brener, Igal, E-mail:, E-mail: [Center for Integrated Nanotechnologies, Sandia National Laboratories, P.O. Box 5800, Albuquerque, New Mexico 87185 (United States); Sandia National Laboratories, P.O. Box 5800, Albuquerque, New Mexico 87185 (United States); Allerman, Andrew A.; Wendt, Joel R.; Shaner, Eric A. [Sandia National Laboratories, P.O. Box 5800, Albuquerque, New Mexico 87185 (United States); Song, Alex Y. [Electrical Engineering Department, Princeton University, EQuad, Olden St, Princeton, New Jersy 08540 (United States)


    We use planar metamaterial resonators to enhance by more than two orders of magnitude the near infrared second harmonic generation obtained from intersubband transitions in III-Nitride heterostructures. The improvement arises from two factors: employing an asymmetric double quantum well design and aligning the resonators' cross-polarized resonances with the intersubband transition energies. The resulting nonlinear metamaterial operates at wavelengths where single photon detection is available, and represents a different class of sources for quantum photonics related phenomena.

  4. Waveguide-coupled directional Raman radiation for surface analysis. (United States)

    Chen, Chen; Li, Jin-Yang; Wang, Li; Lu, Dan-Feng; Qi, Zhi-Mei


    Kretschmann-type waveguide structures, including Plasmon Waveguide (PW) and Resonant Mirror (RM), have been applied in interfacial Raman spectroscopy due to the following unique features: (1) unlike the classic surface enhanced Raman scattering (SERS) substrates made of either gold or silver, both PW and RM can be prepared using a large variety of inexpensive materials; (2) the field enhancement factors using these structures can be theoretically predicted and experimentally controlled, which enables us to manipulate the surface Raman sensitivity with high repeatability; (3) the use of transverse electric (TE) and transverse magnetic (TM) modes for Raman excitation allows us to evaluate the orientation of target molecules immobilized on the waveguide surface; (4) the unwanted impact of noble metals on the Raman fingerprints of target molecules, which is often observed for conventional SERS substrates, can be avoided upon the use of dielectric waveguides. In this paper, guided-mode-coupled directional Raman emission, which is an additional important feature of the waveguide Raman technique, was theoretically investigated based on the optical reciprocity theorem combined with the Fresnel equations. The simulation results indicate that the directional Raman emission from a dipole located within the field confinement and penetration depth of a guided mode depends on both the orientation of the dipole and its distance from the waveguide surface. Raman light from the TE-oriented dipoles is launched into the prism coupler at the TE-mode resonance angle and that from the non-TE-oriented dipoles propagates at the TM-mode resonance angle. The intensity of the guided-mode-excited Raman signal propagating at the mode resonance angle is proportional to the fourth power of the mode field (E(4)) at the depth of the dipole from the waveguide surface. This means that the guided-mode-excited and guided-mode-coupled directional Raman spectroscopy has a detection depth that is as

  5. Experimental investigation of plasmofluidic waveguides

    Energy Technology Data Exchange (ETDEWEB)

    Ku, Bonwoo; Kwon, Min-Suk, E-mail: [School of Electrical and Computer Engineering, UNIST, 50 UNIST-gil, Eonyang-eup, Ulju-gun, Ulsan 689-798 (Korea, Republic of); Shin, Jin-Soo [Department of Electrical Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)


    Plasmofluidic waveguides are based on guiding light which is strongly confined in fluid with the assistance of a surface plasmon polariton. To realize plasmofluidic waveguides, metal-insulator-silicon-insulator-metal (MISIM) waveguides, which are hybrid plasmonic waveguides fabricated using standard complementary metal-oxide-semiconductor technology, are employed. The insulator of the MISIM waveguide is removed to form 30-nm-wide channels, and they are filled with fluid. The plasmofluidic waveguide has a subwavelength-scale mode area since its mode is strongly confined in the fluid. The waveguides are experimentally characterized for different fluids. When the refractive index of the fluid is 1.440, the plasmofluidic waveguide with 190-nm-wide silicon has propagation loss of 0.46 dB/μm; the coupling loss between it and an ordinary silicon photonic waveguide is 1.79 dB. The propagation and coupling losses may be reduced if a few fabrication-induced imperfections are removed. The plasmofluidic waveguide may pave the way to a dynamically phase-tunable ultracompact device.

  6. High-Index Contrast Silicon Rich Silicon Nitride Optical Waveguides and Devices

    DEFF Research Database (Denmark)

    Philipp, Hugh Taylor


    This research focused on the realization of high-density integrated optical devices made with high-index contrast waveguides. The material platform used for to develop these devices was modeled after standard silicon on silicon technology. The high-index waveguide core material was silicon rich...... silicon nitride. This provided a sharp contrast with silica and made low-loss waveguide bending radii less than 25mm possible. An immediate consequence of such small bending radii is the ability to make practical ring resonator based devices with a large free spectral range. Several ring resonator based...... devices have been demonstrated. Directly UV-written waveguides have also been used with high-index contrast ring resonators to make hybrid devices. These hybrid devices are interesting because of the possibility of making practical low insertion-loss devices that utilize the benefits of a high...

  7. Si3N4 grated waveguide optical cavity based sensors for bulk-index concentration, label-free protein, and mechano-optical gas sensing

    NARCIS (Netherlands)

    Pham Van So, P.V.S.; Dijkstra, Mindert; Hollink, Anton; de Ridder, R.M.; Pollnau, Markus; Hoekstra, Hugo

    A grated waveguide (GWG), which is a waveguide with a finite-length grated section, acts as an optical resonator, showing sharp fringes in the transmission spectrum near the stop-band edges of the grating. These oscillations are due to Fabry-Perot resonances of Bloch modes propagating in the cavity

  8. Orientation-Dependent Exciton-Plasmon Coupling in Embedded Organic/Metal Nanowire Heterostructures. (United States)

    Li, Yong Jun; Hong, Yan; Peng, Qian; Yao, Jiannian; Zhao, Yong Sheng


    The excitation of surface plasmons by optical emitters based on exciton-plasmon coupling is important for plasmonic devices with active optical properties. It has been theoretically demonstrated that the orientation of exciton dipole can significantly influence the coupling strength, yet systematic study of the coupling process in nanostructures is still hindered by the lack of proper material systems. In this work, we have experimentally investigated the orientation-dependent exciton-plasmon coupling in a rationally designed organic/metal nanowire heterostructure system. The heterostructures were prepared by inserting silver nanowires into crystalline organic waveguides during the self-assembly of dye molecules. Structures with different exciton orientations exhibited varying coupling efficiencies. The near-field exciton-plasmon coupling facilitates the design of nanophotonic devices based on the directional surface plasmon polariton propagations.

  9. Wakefield in a waveguide (United States)

    Bliokh, Y. P.; Leopold, J. G.; Shafir, G.; Shlapakovski, A.; Krasik, Ya. E.


    The feasibility of an experiment which is being set up in our plasma laboratory to study the effect of a wakefield formed by an ultra-short (≤10-9 s) high-power (˜1 GW) microwave (10 GHz) pulse propagating in a cylindrical waveguide filled with an under-dense [(2-5) × 1010 cm-3] plasma is modeled theoretically and simulated by a particle in cell code. It is shown that the radial ponderomotive force plays a circular key role in the wakefield formation by the TM mode waveguide. The model and the simulations show that powerful microwave pulses produce a wakefield at lower plasma density and electric field gradients but larger space and time scales compared to the laser produced wakefield in plasmas, thus providing a more accessible platform for the experimental study.

  10. Waveguide-based optofluidics

    DEFF Research Database (Denmark)

    Karnutsch, Christian; Tomljenovic-Hanic, Snjezana; Monat, Christelle


    blocks in many applications, from microlasers and biomedical sensor systems to optical switches and integrated circuits. In this paper, we show that PhC microcavities can be formed by infusing a liquid into a selected section of a uniform PhC waveguide and that the optical properties of these cavities...... and highlight the benefits of an optofluidic approach, focusing on optofluidic cavities created in silicon photonic crystal (PhC) waveguide platforms. These cavities can be spatially and spectrally reconfigured, thus allowing a dynamic control of their optical characteristics. PhC cavities are major building...... can be tuned and adapted. By taking advantage of the negative thermo-optic coefficient of liquids, we describe a method which renders PhC cavities insensitive to temperature changes in the environment. This is only one example where the fluid-control of optical elements results in a functionality...

  11. Heterostructures of transition metal dichalcogenides

    KAUST Repository

    Amin, Bin


    The structural, electronic, optical, and photocatalytic properties of out-of-plane and in-plane heterostructures of transition metal dichalcogenides are investigated by (hybrid) first principles calculations. The out-of-plane heterostructures are found to be indirect band gap semiconductors with type-II band alignment. Direct band gaps can be achieved by moderate tensile strain in specific cases. The excitonic peaks show blueshifts as compared to the parent monolayer systems, whereas redshifts occur when the chalcogen atoms are exchanged along the series S-Se-Te. Strong absorption from infrared to visible light as well as excellent photocatalytic properties can be achieved.

  12. Anisotropic and nonlinear optical waveguides

    CERN Document Server

    Someda, CG


    Dielectric optical waveguides have been investigated for more than two decades. In the last ten years they have had the unique position of being simultaneously the backbone of a very practical and fully developed technology, as well as an extremely exciting area of basic, forefront research. Existing waveguides can be divided into two sets: one consisting of waveguides which are already in practical use, and the second of those which are still at the laboratory stage of their evolution. This book is divided into two separate parts: the first dealing with anisotropic waveguides, an

  13. Improving nanocavity switching using Fano resonances in photonic crystal structures

    DEFF Research Database (Denmark)

    Heuck, Mikkel; Kristensen, Philip Trøst; Elesin, Yuriy


    We present a simple design for achieving Fano resonances in photonic crystal coupled waveguide-cavity structures. A coupled mode theory analysis shows an order of magnitude reduction in switching energy compared to conventional Lorentz resonances....

  14. Low crosstalk Arrayed Waveguide Grating with Cascaded Waveguide Grating Filter

    Energy Technology Data Exchange (ETDEWEB)

    Deng Yang; Liu Yuan; Gao Dingshan, E-mail: [Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China)


    We propose a highly compact and low crosstalk arrayed waveguide grating (AWG) with cascaded waveguide grating (CWGF). The side lobes of the silicon nanowire AWG, which are normally introduced by fabrication errors, can be effectively suppressed by the CWGF. And the crosstalk can be improved about 15dB.

  15. A Cryogenic Waveguide Mount for Microstrip Circuit and Material Characterization (United States)

    U-yen, Kongpop; Brown, Ari D.; Moseley, Samuel H.; Noroozian, Omid; Wollack, Edward J.


    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.

  16. Fiber-Drawn Metamaterial for THz Waveguiding and Imaging (United States)

    Atakaramians, Shaghik; Stefani, Alessio; Li, Haisu; Habib, Md. Samiul; Hayashi, Juliano Grigoleto; Tuniz, Alessandro; Tang, Xiaoli; Anthony, Jessienta; Lwin, Richard; Argyros, Alexander; Fleming, Simon C.; Kuhlmey, Boris T.


    In this paper, we review the work of our group in fabricating metamaterials for terahertz (THz) applications by fiber drawing. We discuss the fabrication technique and the structures that can be obtained before focusing on two particular applications of terahertz metamaterials, i.e., waveguiding and sub-diffraction imaging. We show the experimental demonstration of THz radiation guidance through hollow core waveguides with metamaterial cladding, where substantial improvements were realized compared to conventional hollow core waveguides, such as reduction of size, greater flexibility, increased single-mode operating regime, and guiding due to magnetic and electric resonances. We also report recent and new experimental work on near- and far-field THz imaging using wire array metamaterials that are capable of resolving features as small as λ/28.

  17. Fiber-Drawn Metamaterial for THz Waveguiding and Imaging

    DEFF Research Database (Denmark)

    Atakaramians, Shaghik; Stefani, Alessio; Li, Haisu


    In this paper, we review the work of our group in fabricating metamaterials for terahertz (THz) applications by fiber drawing. We discuss the fabrication technique and the structures that can be obtained before focusing on two particular applications of terahertz metamaterials, i.e., waveguiding...... and sub-diffraction imaging. We show the experimental demonstration of THz radiation guidance through hollow core waveguides with metamaterial cladding, where substantial improvements were realized compared to conventional hollow core waveguides, such as reduction of size, greater flexibility, increased...... single-mode operating regime, and guiding due to magnetic and electric resonances. We also report recent and new experimental work on near- and far-field THz imaging using wire array metamaterials that are capable of resolving features as small as λ/28....

  18. Arrays of strongly coupled atoms in a one-dimensional waveguide (United States)

    Ruostekoski, Janne; Javanainen, Juha


    We study the cooperative optical coupling between regularly spaced atoms in a one-dimensional waveguide using decompositions to subradiant and super-radiant collective excitation eigenmodes, direct numerical solutions, and analytical transfer-matrix methods. We illustrate how the spectrum of transmitted light through the waveguide, including the emergence of narrow Fano resonances, can be understood by the resonance features of the eigenmodes. We describe a method based on super-radiant and subradiant modes to engineer the optical response of the waveguide and to store light. The stopping of light is obtained by transferring an atomic excitation to a subradiant collective mode with the zero radiative resonance linewidth by controlling the level shift of an atom in the waveguide. Moreover, we obtain an exact analytic solution for the transmitted light through the waveguide for the case of a regular lattice of atoms and provide a simple description of how the light transmission may present large resonance shifts when the lattice spacing is close, but not exactly equal, to half of the wavelength of the light. Experimental imperfections such as fluctuations of the positions of the atoms and loss of light from the waveguide are easily quantified in the numerical simulations, which produce the natural result that the optical response of the atomic array tends toward the response of a gas with random atomic positions.

  19. Determination of electromagnetic modes in oversized corrugated waveguides on the electron cyclotron resonance heating installation at the tokamak Tore Supra; Determination de modes electromagnetiques de guides d'ondes corrugues surdimensionnes sur l'installation de chauffage des electrons de tokamak Tore Supra

    Energy Technology Data Exchange (ETDEWEB)

    Courtois, L


    Electron cyclotron resonance heating (ECRH) in the Tore Supra tokamak constitutes an important step in the research aimed at obtaining thermonuclear fusion reactions. Electron heating is achieved by transmitting an electromagnetic wave from the oscillators (gyrotrons) to the plasma via the fundamental mode, propagating in oversized corrugated waveguides. Maximizing the proportion of the gyrotron power coupled to the fundamental waveguide mode is essential for the good functioning of the transmission line and for maximizing the effect on the plasma. This thesis gives all necessary tools for finding the proportion of the fundamental mode and all other modes present in passive components and at the output of the gyrotron as installed in the Tore Supra ECRH plant. This characterisation is based on obtaining amplitude and phase diagrams of the electric field on a plane transverse to the propagation axis. The most difficult part of obtaining these diagrams is measuring the phase which, despite the very short wavelength, is measured directly at low power levels. At high power levels the phase is numerically reconstructed from amplitude measurements for gyrotron characterisation. A complete theoretical study of the phase reconstruction code is given including its validation with theoretical diagrams. This study allows the realisation of a modal characterisation unit electromagnetic for measurement of radiated beams and usable in each part of the ECRH installation. At the end, the complete modal characterisation is given at low level for a mode converter and also at high level for the first series gyrotron installed at TORE SUPRA. (author)

  20. Escher-like quasiperiodic heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Barriuso, A G; Monzon, J J; Sanchez-Soto, L L [Departamento de Optica, Facultad de Fisica, Universidad Complutense, 28040 Madrid (Spain); Costa, A F [Departamento de Matematicas Fundamentales, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, Senda del Rey 9, 28040 Madrid (Spain)


    Quasiperiodic heterostructures present unique structural, electronic and vibrational properties, connected to the existence of incommensurate periods. We go beyond previous schemes, such as Fibonacci or Thue-Morse, based on substitutional sequences, by introducing construction rules generated by tessellations of the unit disc by regular polygons. We explore some of the properties exhibited by these systems. (fast track communication)

  1. Controlling collective spontaneous emission with plasmonic waveguides. (United States)

    Li, Ying; Argyropoulos, Christos


    We demonstrate a plasmonic route to control the collective spontaneous emission of two-level quantum emitters. Superradiance and subradiance effects are observed over distances comparable to the operating wavelength inside plasmonic nanochannels. These plasmonic waveguides can provide an effective epsilon-near-zero operation in their cut-off frequency and Fabry-Pérot resonances at higher frequencies. The related plasmonic resonant modes are found to efficiently enhance the constructive (superradiance) or destructive (subradiance) interference between different quantum emitters located inside the waveguides. By increasing the number of emitters located in the elongated plasmonic channel, the superradiance effect is enhanced at the epsilon-near-zero operation, leading to a strong coherent increase in the collective spontaneous emission rate. In addition, the separation distance between neighboring emitters and their emission wavelengths can be changed to dynamically control the collective emission properties of the plasmonic system. It is envisioned that the dynamic modification between quantum superradiant and subradiant modes will find applications in quantum entanglement of qubits, low-threshold nanolasers and efficient sensors.

  2. A metamolecule antenna for coplanar waveguides. (United States)

    Maple, L C; Berry, S A; Stenning, G B G; Bowden, G J; de Groot, P A J; Apostolopoulos, V


    We report on a metamolecule antenna, based on a fish-scale design but augmented with two split-ring resonators (SRRs) placed within the fish-scale loops. The properties of the antenna resonator, with and without additional SRRs, were examined using finite element method simulations (COMSOL Multiphysics). The simulation findings were subsequently confirmed experimentally, using a vector network analyser coupled to an antenna-loaded coplanar waveguide (CPW). The addition of SRRs to the fish-scale meta-molecule leads to a demonstrably large increase in microwave-absorption. It is shown that the fish-scale/SRR/CPW combination performs as a microwave antenna. Simulations of the antenna gain and far-field emission are presented and discussed.

  3. Analysis of integrated optical waveguides

    NARCIS (Netherlands)

    Uranus, H.P.; Hoekstra, Hugo; van Groesen, Embrecht W.C.


    An overview of the analysis of integrated optical waveguides is presented. Starting from the Maxwell’s equations, a formulation of the problem for general 3-D structures will be introduced. Then, for longitudinally invariant structures, problem for waveguides with 2-D cross section is presented for

  4. Compact titanium dioxide waveguides with high nonlinearity at telecommunication wavelengths. (United States)

    Guan, Xiaowei; Hu, Hao; Oxenløwe, Leif K; Frandsen, Lars H


    Dense integration of photonic integrated circuits demands waveguides simultaneously fulfilling requirements on compactness, low loss, high nonlinearity, and capabilities for mass production. In this work, titanium dioxide waveguides with a thick core of 380 nm exhibiting a compact mode size (0.43 μm2) and a low loss (5.4 ± 1 dB/cm) at telecommunication wavelengths around 1550 nm have been fabricated and measured. A microring resonator having a 50 μm radius has been measured to have a loaded quality factor of 53500. Four-wave mixing experiments reveal a nonlinear parameter for the waveguides of 21-34 W-1 m-1 corresponding to a nonlinear index around 2.3-3.6 x 10-18 m2/W, which results in a wavelength conversion efficiency of -36.2 dB. These performances, together with the potentially simple dispersion engineering to the fabricated waveguides by the post processes, yield a strong promise for the titanium dioxide waveguides applied in photonic integrated circuits, especially for nonlinear implementations.

  5. Nano-optical conveyor belt with waveguide-coupled excitation. (United States)

    Wang, Guanghui; Ying, Zhoufeng; Ho, Ho-pui; Huang, Ying; Zou, Ningmu; Zhang, Xuping


    We propose a plasmonic nano-optical conveyor belt for peristaltic transport of nano-particles. Instead of illumination from the top, waveguide-coupled excitation is used for trapping particles with a higher degree of precision and flexibility. Graded nano-rods with individual dimensions coded to have resonance at specific wavelengths are incorporated along the waveguide in order to produce spatially addressable hot spots. Consequently, by switching the excitation wavelength sequentially, particles can be transported to adjacent optical traps along the waveguide. The feasibility of this design is analyzed using three-dimensional finite-difference time-domain and Maxwell stress tensor methods. Simulation results show that this system is capable of exciting addressable traps and moving particles in a peristaltic fashion with tens of nanometers resolution. It is the first, to the best of our knowledge, report about a nano-optical conveyor belt with waveguide-coupled excitation, which is very important for scalability and on-chip integration. The proposed approach offers a new design direction for integrated waveguide-based optical manipulation devices and its application in large scale lab-on-a-chip integration.

  6. Transverse magnetic mode along THz waveguides with biased superlattices

    Energy Technology Data Exchange (ETDEWEB)

    Aceituno, P. [Dpto. Fisica Basica, Universidad de La Laguna, La Laguna, 38206 Tenerife (Spain)], E-mail:; Hernandez-Cabrera, A. [Dpto. Fisica Basica, Universidad de La Laguna, La Laguna, 38206 Tenerife (Spain); Vasko, F.T. [Institute of Semiconductor Physics, NAS Ukraine, Pr. Nauki 41, Kiev 03028 (Ukraine)


    We study the propagation of transverse magnetic modes arising from a waveguide consisting on a GaAs-based superlattice located at vacuum-dielectric interface. The transverse mode is generated by the ultrafast intersubband response of the superlattice subjected to a high-frequency electric field. The superlattice is also subjected to a homogeneous bias potential to get a biased superlattice with equipopulated levels. The heterostructure is analyzed through the tight-binding approximation, and considering the level broadening caused by different scattering processes (homogeneous and inhomogeneous broadening mechanisms). We pay special attention to the dispersion relations of the complex dielectric permittivity because of real and imaginary parts of this function play a key role in wide miniband superlattices.

  7. Optical waveguides with compound multiperiodic grating nanostructures for refractive index sensing

    DEFF Research Database (Denmark)

    Neustock, Lars Thorben; Jahns, Sabrina; Adam, Jost


    The spectral characteristics and refractive index sensitivity of compound multiperiodic grating waveguides are investigated in theory and experiment. Compound gratings are formed by superposition of two or more monoperiodic gratings. Compared to monoperiodic photonic crystal waveguides, compound...... grating waveguides offer more degrees of design freedom by choice of component grating periods and duty cycles. Refractive index sensing is achieved by evaluating the wavelength or intensity of guided-mode resonances in the reflection spectrum. We designed, fabricated and characterized 24 different...... compound multiperiodic nanostructured waveguides for refractive index sensing. Simulations are carried out with the Rigorous Coupled Wave Algorithm (RCWA). The resulting spectra, resonance sensitivities and quality factors are compared to monoperiodic as well as to three selected aperiodic nanostructures...

  8. Superconducting Coplanar Waveguide Filters for Submillimeter Wave On-Chip Filterbank Spectrometers

    NARCIS (Netherlands)

    Endo, A.; Yates, S. J. C.; Bueno, J.; Thoen, D. J.; Murugesan, V.; Baryshev, A. M.; Klapwijk, T. M.; van der Werf, P. P.; Baselmans, J. J. A.


    We show the first experimental results which prove that superconducting NbTiN coplanar-waveguide resonators can achieve a loaded Q factor in excess of 800 in the 350 GHz band. These resonators can be used as narrow band pass filters for on-chip filter bank spectrometers for astronomy. Moreover, the

  9. Superconducting Coplanar Waveguide Filters for Submillimeter Wave On-Chip Filterbank Spectrometers

    NARCIS (Netherlands)

    Endo, A.; Yates, S.J.C.; Bueno, J.; Thoen, D.J.; Murugesan, V.; Baryshev, A.M.; Klapwijk, T.M.; Van der Werf, P.P.; Baselmans, J.J.A.


    We show the first experimental results which prove that superconducting NbTiN coplanar–waveguide resonators can achieve a loaded Q factor in excess of 800 in the 350 GHz band. These resonators can be used as narrow band pass filters for on-chip filter bank spectrometers for astronomy. Moreover, the

  10. High speed heterostructure devices

    CERN Document Server

    Beer, Albert C; Willardson, R K; Kiehl, Richard A; Sollner, T C L Gerhard


    Volume 41 includes an in-depth review of the most important, high-speed switches made with heterojunction technology. This volume is aimed at the graduate student or working researcher who needs a broad overview andan introduction to current literature. Key Features * The first complete review of InP-based HFETs and complementary HFETs, which promise very low power and high speed * Offers a complete, three-chapter review of resonant tunneling * Provides an emphasis on circuits as well as devices.

  11. Coupled equations of electromagnetic waves in nonlinear metamaterial waveguides. (United States)

    Azari, Mina; Hatami, Mohsen; Meygoli, Vahid; Yousefi, Elham


    Over the past decades, scientists have presented ways to manipulate the macroscopic properties of a material at levels unachieved before, and called them metamaterials. This research can be considered an important step forward in electromagnetics and optics. In this study, higher-order nonlinear coupled equations in a special kind of metamaterial waveguides (a planar waveguide with metamaterial core) will be derived from both electric and magnetic components of the transverse electric mode of electromagnetic pulse propagation. On the other hand, achieving the refractive index in this research is worthwhile. It is also shown that the coupled equations are not symmetric with respect to the electric and magnetic fields, unlike these kinds of equations in fiber optics and dielectric waveguides. Simulations on the propagation of a fundamental soliton pulse in a nonlinear metamaterial waveguide near the resonance frequency (a little lower than the magnetic resonant frequency) are performed to study its behavior. These pulses are recommended to practice in optical communications in controlled switching by external voltage, even in low power.

  12. Photonic crystal waveguide-based biosensor for detection of diseases (United States)

    Chopra, Harshita; Kaler, Rajinder S.; Painam, Balveer


    A biosensor is a device that is used to detect the analytes or molecules of a sample by means of a binding mechanism. A two-dimensional photonic crystal waveguide-based biosensor is designed with a diamond-shaped ring resonator and two waveguides: a bus waveguide and a drop waveguide. The sensing mechanism is based on change in refractive index of the analytes, leading to a shift in the peak resonant wavelength. This mechanism can be used in the field of biomedical treatment where different body fluids such as blood, tears, saliva, or urine can be used as the analyte in which different components of the fluid can be detected. It can also be used to differentiate between the cell lines of a normal and an unhealthy human being. Average value of quality factor for this device comes out to be 1082.2063. For different analytes used, the device exhibits enhanced sensitivity and, hence, it is useful for the detection of diseases.

  13. High-efficiency dual-polarized patch antenna array with common waveguide feed


    Vilaltella Esteve, Robert


    Treball realitzat a l'Institut für Hochfrequenztechnik (IHF)de la Universität Stuttgart [ANGLÈS] A concept for a dual-polarized patch antenna array with large bandwidth and high efficiency is proposed. A short overmoded waveguide section is connected to a square feed waveguide on one side, and to the common groundplane of a 2x2 or a 3x3 patch array on the other side. Each square-shaped patch is coupled to the waveguide by crossed slots in the groundplane. The coupled resonances of the patc...

  14. Analysis of the multipactor effect in circular waveguides excited by two orthogonal polarization waves

    Energy Technology Data Exchange (ETDEWEB)

    Pérez, A. M.; Boria, V. E. [Departamento de Comunicaciones-iTEAM, Universidad Politécnica de Valencia Camino de Vera s/n, 46022 Valencia (Spain); Gimeno, B. [Departamento de Física Aplicada y Electromagnetismo-ICMUV, Universitat de València c/Dr. Moliner, 50, 46100 Valencia (Spain); Anza, S.; Vicente, C.; Gil, J. [Aurora Software and Testing S.L., Edificio de Desarrollo Empresarial 9B, Universidad Politécnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain)


    Circular waveguides, either employed as resonant cavities or as irises connecting adjacent guides, are widely present in many passive components used in different applications (i.e., particle accelerators and satellite subsystems). In this paper, we present the study of the multipactor effect in circular waveguides considering the coexistence of the two polarizations of the fundamental TE{sub 11} circular waveguide mode. For a better understanding of the problem, only low multipactor orders have been explored as a function of the polarization ellipse eccentricity. Special attention has been paid to the linear and circular polarizations, but other more general configurations have also been explored.

  15. Second-order virial expansion for an atomic gas in a harmonic waveguide (United States)

    Kristensen, Tom; Leyronas, Xavier; Pricoupenko, Ludovic


    The virial expansion for cold two-component Fermi and Bose atomic gases is considered in the presence of a waveguide and in the vicinity of a Feshbach resonance. The interaction between atoms and the coupling with the Feshbach molecules is modeled using a quantitative separable two-channel model. The scattering phase shift in an atomic waveguide is defined. This permits us to extend the Beth-Uhlenbeck formula for the second-order virial coefficient to this inhomogeneous case.

  16. Freeform Phononic Waveguides

    Directory of Open Access Journals (Sweden)

    Georgios Gkantzounis


    Full Text Available We employ a recently introduced class of artificial structurally-disordered phononic structures that exhibit large and robust elastic frequency band gaps for efficient phonon guiding. Phononic crystals are periodic structures that prohibit the propagation of elastic waves through destructive interference and exhibit large band gaps and ballistic propagation of elastic waves in the permitted frequency ranges. In contrast, random-structured materials do not exhibit band gaps and favour localization or diffusive propagation. Here, we use structures with correlated disorder constructed from the so-called stealthy hyperuniform disordered point patterns, which can smoothly vary from completely random to periodic (full order by adjusting a single parameter. Such amorphous-like structures exhibit large band gaps (comparable to the periodic ones, both ballistic-like and diffusive propagation of elastic waves, and a large number of localized modes near the band edges. The presence of large elastic band gaps allows the creation of waveguides in hyperuniform materials, and we analyse various waveguide architectures displaying nearly 100% transmission in the GHz regime. Such phononic-circuit architectures are expected to have a direct impact on integrated micro-electro-mechanical filters and modulators for wireless communications and acousto-optical sensing applications.

  17. Nanowire resonant tunneling diodes (United States)

    Björk, M. T.; Ohlsson, B. J.; Thelander, C.; Persson, A. I.; Deppert, K.; Wallenberg, L. R.; Samuelson, L.


    Semiconductor heterostructures and their implementation into electronic and photonic devices have had tremendous impact on science and technology. In the development of quantum nanoelectronics, one-dimensional (1D) heterostructure devices are receiving a lot of interest. We report here functional 1D resonant tunneling diodes obtained via bottom-up assembly of designed segments of different semiconductor materials in III/V nanowires. The emitter, collector, and the central quantum dot are made from InAs and the barrier material from InP. Ideal resonant tunneling behavior, with peak-to-valley ratios of up to 50:1 and current densities of 1 nA/μm2 was observed at low temperatures.

  18. Resonant optical device with a microheater (United States)

    Lentine, Anthony L.; DeRose, Christopher


    A resonant photonic device is provided. The device comprises an optical waveguiding element, such as an optical resonator, that includes a diode junction region, two signal terminals configured to apply a bias voltage across the junction region, and a heater laterally separated from the optical waveguiding element. A semiconductor electrical barrier element is juxtaposed to the heater. A metallic strip is electrically and thermally connected at one end to a signal terminal of the optical waveguiding element and thermally connected at another end to the barrier element.

  19. The ideal imaging AR waveguide (United States)

    Grey, David J.


    Imaging waveguides are a key development that are helping to create the Augmented Reality revolution. They have the ability to use a small projector as an input and produce a wide field of view, large eyebox, full colour, see-through image with good contrast and resolution. WaveOptics is at the forefront of this AR technology and has developed and demonstrated an approach which is readily scalable. This paper presents our view of the ideal near-to-eye imaging AR waveguide. This will be a single-layer waveguide which can be manufactured in high volume and low cost, and is suitable for small form factor applications and all-day wear. We discuss the requirements of the waveguide for an excellent user experience. When enhanced (AR) viewing is not required, the waveguide should have at least 90% transmission, no distracting artifacts and should accommodate the user's ophthalmic prescription. When enhanced viewing is required, additionally, the waveguide requires excellent imaging performance, this includes resolution to the limit of human acuity, wide field of view, full colour, high luminance uniformity and contrast. Imaging waveguides are afocal designs and hence cannot provide ophthalmic correction. If the user requires this correction then they must wear either contact lenses, prescription spectacles or inserts. The ideal imaging waveguide would need to cope with all of these situations so we believe it must be capable of providing an eyebox at an eye relief suitable for spectacle wear which covers a significant range of population inter-pupillary distances. We describe the current status of our technology and review existing imaging waveguide technologies against the ideal component.

  20. Hollow waveguide for urology treatment (United States)

    Jelínková, H.; Němec, M.; Koranda, P.; Pokorný, J.; Kőhler, O.; Drlík, P.; Miyagi, M.; Iwai, K.; Matsuura, Y.


    The aim of our work was the application of the special sealed hollow waveguide system for the urology treatment - In our experimental study we have compared the effects of Ho:YAG (wavelength 2100 nm) and Er:YAG (wavelength 2940 nm) laser radiation both on human urinary stones (or compressed plaster samples which serve as a model) fragmentation and soft ureter tissue incision in vitro. Cyclic Olefin Polymer - coated silver (COP/Ag) hollow glass waveguides with inner and outer diameters 700 and 850 μm, respectively, were used for the experiment. To prevent any liquid to diminish and stop the transmission, the waveguide termination was utilized.

  1. Waveguide-based OPO source of entangled photon pairs

    Energy Technology Data Exchange (ETDEWEB)

    Pomarico, Enrico; Sanguinetti, Bruno; Gisin, Nicolas; Thew, Robert; Zbinden, Hugo [Group of Applied Physics, University of Geneva, 1211 Geneva (Switzerland); Schreiber, Gerhard; Thomas, Abu; Sohler, Wolfgang [Angewandte Physik, University of Paderborn, 33095 Paderborn (Germany)], E-mail:


    In this paper, we present a compact source of narrow-band energy-time-entangled photon pairs in the telecom regime based on a Ti-indiffused periodically poled lithium niobate (PPLN) waveguide resonator, i.e. a waveguide with end-face dielectric multi-layer mirrors. This is a monolithic doubly resonant optical parametric oscillator (OPO) far below threshold, which generates photon pairs by spontaneous parametric down-conversion (SPDC) at around 1560 nm with a 117 MHz (0.91 pm)-bandwidth. A coherence time of 2.7 ns is estimated by a time correlation measurement and a high quality of the entangled states is confirmed by a Bell-type experiment. Since highly coherent energy-time-entangled photon pairs in the telecom regime are suitable for long distance transmission and manipulation, this source is well suited to the requirements of quantum communication.

  2. Low-Loss Polymer-Based Ring Resonator for Resonant Integrated Optical Gyroscopes

    Directory of Open Access Journals (Sweden)

    Guang Qian


    Full Text Available Waveguide ring resonator is the sensing element of resonant integrated optical gyroscope (RIOG. This paper reports a polymer-based ring resonator with a low propagation loss of about 0.476 dB/cm for RIOG. The geometrical parameters of the waveguide and the coupler of the resonator were optimally designed. We also discussed the optical properties and gyroscope performance of the polymer resonator which shows a high quality factor of about 105. The polymer-based RIOG exhibits a limited sensitivity of less than 20 deg/h for the low and medium resolution navigation systems.

  3. Magnetic interaction in all silicon waveguide spherical coupler device. (United States)

    Shi, Lei; Meseguer, Francisco


    The magnetic field component of light in dielectric materials generally plays a negligible role at optical frequency values. However, it is a key component of metal based metamaterials. Here we report on the dominant role of the magnetic interaction in a dielectric spherical silicon nanocavity coupled to a silicon waveguide. The analytical method, as well as the finite difference time domain (FDTD) simulation, show a three dimensional (3D) magnetic trap effect when the magnetic like Mie resonances of the nanocavity are excited.

  4. Silicon waveguide optical switch with embedded phase change material. (United States)

    Miller, Kevin J; Hallman, Kent A; Haglund, Richard F; Weiss, Sharon M


    Phase-change materials (PCMs) have emerged as promising active elements in silicon (Si) photonic systems. In this work, we design, fabricate, and characterize a hybrid Si-PCM optical switch. By integrating vanadium dioxide (a PCM) within a Si photonic waveguide, in a non-resonant geometry, we achieve ~10 dB broadband optical contrast with a PCM length of 500 nm using thermal actuation.

  5. Fundamentals of optical waveguides

    CERN Document Server

    Okamoto, Katsunari


    Fundamentals of Optical Waveguides is an essential resource for any researcher, professional or student involved in optics and communications engineering. Any reader interested in designing or actively working with optical devices must have a firm grasp of the principles of lightwave propagation. Katsunari Okamoto has presented this difficult technology clearly and concisely with several illustrations and equations. Optical theory encompassed in this reference includes coupled mode theory, nonlinear optical effects, finite element method, beam propagation method, staircase concatenation method, along with several central theorems and formulas. Since the publication of the well-received first edition of this book, planar lightwave circuits and photonic crystal fibers have fully matured. With this second edition the advances of these fibers along with other improvements on existing optical technologies are completely detailed. This comprehensive volume enables readers to fully analyze, design and simulate opti...

  6. Optical waveguide theory

    CERN Document Server

    Snyder, Allan W


    This text is intended to provide an in-depth, self-contained, treatment of optical waveguide theory. We have attempted to emphasize the underlying physical processes, stressing conceptual aspects, and have developed the mathematical analysis to parallel the physical intuition. We also provide comprehensive supplementary sections both to augment any deficiencies in mathematical background and to provide a self-consistent and rigorous mathematical approach. To assist in. understanding, each chapter con­ centrates principally on a single idea and is therefore comparatively short. Furthermore, over 150 problems with complete solutions are given to demonstrate applications of the theory. Accordingly, through simplicity of approach and numerous examples, this book is accessible to undergraduates. Many fundamental topics are presented here for the first time, but, more importantly, the material is brought together to give a unified treatment of basic ideas using the simplest approach possible. To achieve such a goa...

  7. Polymer Waveguide Fabrication Techniques (United States)

    Ramey, Delvan A.


    The ability of integrated optic systems to compete in signal processing aplications with more traditional analog and digital electronic systems is discussed. The Acousto-Optic Spectrum Analyzer is an example which motivated the particular work discussed herein. Provided real time processing is more critical than absolute accuracy, such integrated optic systems fulfill a design need. Fan-out waveguide arrays allow crosstalk in system detector arrays to be controlled without directly limiting system resolution. A polyurethane pattern definition process was developed in order to demonstrate fan-out arrays. This novel process is discussed, along with further research needs. Integrated optic system market penetration would be enhanced by development of commercial processes of this type.

  8. Magnetic waveguides for neutron reflectometry (United States)

    Khaydukov, Yu.; Petrzhik, A. M.; Borisenko, I. V.; Kalabukhov, A.; Winkler, D.; Keller, T.; Ovsyannikov, G. A.; Keimer, B.


    We show that the sensitivity and depth selectivity of neutron reflectometry can be greatly enhanced through a waveguide design that takes advantage of the spin-dependent magnetic neutron scattering potential to steer spin-up and spin-down neutrons into waveguide modes with different depth profiles. Using a bilayer of manganate and ruthenate ferromagnets, we demonstrate that a magnetic waveguide structure with sharp spin-up and spin-down modes centered in the two different layers can be generated by adding a magnetically inactive capping layer. The resulting reflectometric data allow accurate and reliable determination of a small in-plane magnetization in the ruthenate layer, despite its immediate proximity to the manganate layer with much larger magnetization. Magnetic neutron waveguides thus enable depth-sensitive measurements of small electronic spin polarizations in a large variety of magnetic multilayers and devices.

  9. Analysis of integrated optical waveguides


    Uranus, H.P.; Hoekstra, Hugo; van Groesen, Embrecht W.C.


    An overview of the analysis of integrated optical waveguides is presented. Starting from the Maxwell’s equations, a formulation of the problem for general 3-D structures will be introduced. Then, for longitudinally invariant structures, problem for waveguides with 2-D cross section is presented for vectorial, semivectorial, and scalar formulations. Simpler 1-D case for planar structure will then be discussed in more detail. A novel scheme developed for the analysis of planar structures is giv...

  10. 3D integration of photonic crystal devices: vertical coupling with a silicon waveguide. (United States)

    Ferrier, L; Romeo, P Rojo; Letartre, X; Drouard, E; Viktorovitch, P


    Two integrated devices based on the vertical coupling between a photonic crystal microcavity and a silicon (Si) ridge waveguide are presented in this paper. When the resonator is coupled to a single waveguide, light can be spectrally extracted from the waveguide to free space through the far field emission of the resonator. When the resonator is vertically coupled to two waveguides, a vertical add-drop filter can be realized. The dropping efficiency of these devices relies on a careful design of the resonator. In this paper, we use a Fabry-Perot (FP) microcavity composed of two photonic crystal (PhC) slab mirrors. Thanks to the unique dispersion properties of slow Bloch modes (SBM) at the flat extreme of the dispersion curve, it is possible to design a FP cavity exhibiting two quasi-degenerate modes. This specific configuration allows for a coupling efficiency that can theoretically achieve 100%. Using 3D FDTD calculations, we discuss the design of such devices and show that high dropping efficiency can be achieved between the Si waveguides and the PhC microcavity.

  11. Attenuation in Superconducting Circular Waveguides

    Directory of Open Access Journals (Sweden)

    K. H. Yeap


    Full Text Available We present an analysis on wave propagation in superconducting circular waveguides. In order to account for the presence of quasiparticles in the intragap states of a superconductor, we employ the characteristic equation derived from the extended Mattis-Bardeen theory to compute the values of the complex conductivity. To calculate the attenuation in a circular waveguide, the tangential fields at the boundary of the wall are first matched with the electrical properties (which includes the complex conductivity of the wall material. The matching of fields with the electrical properties results in a set of transcendental equations which is able to accurately describe the propagation constant of the fields. Our results show that although the attenuation in the superconducting waveguide above cutoff (but below the gap frequency is finite, it is considerably lower than that in a normal waveguide. Above the gap frequency, however, the attenuation in the superconducting waveguide increases sharply. The attenuation eventually surpasses that in a normal waveguide. As frequency increases above the gap frequency, Cooper pairs break into quasiparticles. Hence, we attribute the sharp rise in attenuation to the increase in random collision of the quasiparticles with the lattice structure.

  12. Scattering loss of antiresonant reflecting optical waveguides


    Baba, Toshihiko; Kokubun, Yasuo


    Scattering loss of two-dimensional ARROW-type waveguides, i.e., antiresonant reflecting optical waveguide (ARROW) and ARROW-B, is analyzed by the first-order perturbation theory. Calculated results are compared with those of conventional three-layer waveguides. Optimum design for the reduction of scattering loss of these ARROW-type waveguides is discussed. It was found that the scattering loss of ARROW-type waveguides is no larger than that of a conventional waveguide having a relative refrac...

  13. Single tunable laser interrogation of slab-coupled optical sensors through resonance tuning. (United States)

    Chadderdon, Spencer; Woodard, Leeland; Perry, Daniel; Selfridge, Richard H; Schultz, Stephen M


    This paper describes a method for tuning the resonant wavelengths of slab-coupled optical fiber sensors (SCOSs). This method allows multiple sensors to be interrogated simultaneously with a single tunable laser. The resonances are tuned by rotating a biaxial slab waveguide relative to an optical D-fiber. As the slab waveguide rotates, its effective index of refraction changes causing the coupling wavelengths of the slab waveguide and D-fiber to shift. A SCOS fabricated with potassium titanyl phosphate crystal as the slab waveguide is shown to have resonance tuning ranges of 6.67 and 22.24 nm, respectively, for TM and TE polarized modes.

  14. Subwavelength-Sized Narrow-Band Anechoic Waveguide Terminations

    DEFF Research Database (Denmark)

    Santillan, Arturo Orozco; Ærenlund, Emil; Bozhevolnyi, Sergey I.


    We propose and demonstrate the use of a pair of detuned acoustic resonators to efficiently absorb narrowband sound waves in a terminated waveguide. The suggested configuration is relatively simple and advantageous for usage at low frequencies, since the dimensions of the resonators are very small...... compared to the wavelength.We present a theoretical description based on lumped parameters to calculate the absorption coefficient, which agrees very well with experimental data. The experimental results verify that the anechoic (reflection approximately −38 dB) narrow-band (Δf=f ∼ 0.1) termination...

  15. Interlayer Exciton Optoelectronics in a 2D Heterostructure p-n Junction. (United States)

    Ross, Jason S; Rivera, Pasqual; Schaibley, John; Lee-Wong, Eric; Yu, Hongyi; Taniguchi, Takashi; Watanabe, Kenji; Yan, Jiaqiang; Mandrus, David; Cobden, David; Yao, Wang; Xu, Xiaodong


    Semiconductor heterostructures are backbones for solid-state-based optoelectronic devices. Recent advances in assembly techniques for van der Waals heterostructures have enabled the band engineering of semiconductor heterojunctions for atomically thin optoelectronic devices. In two-dimensional heterostructures with type II band alignment, interlayer excitons, where Coulomb bound electrons and holes are confined to opposite layers, have shown promising properties for novel excitonic devices, including a large binding energy, micron-scale in-plane drift-diffusion, and a long population and valley polarization lifetime. Here, we demonstrate interlayer exciton optoelectronics based on electrostatically defined lateral p-n junctions in a MoSe 2 -WSe 2 heterobilayer. Applying a forward bias enables the first observation of electroluminescence from interlayer excitons. At zero bias, the p-n junction functions as a highly sensitive photodetector, where the wavelength-dependent photocurrent measurement allows the direct observation of resonant optical excitation of the interlayer exciton. The resulting photocurrent amplitude from the interlayer exciton is about 200 times smaller than the resonant excitation of intralayer exciton. This implies that the interlayer exciton oscillator strength is 2 orders of magnitude smaller than that of the intralayer exciton due to the spatial separation of electron and hole to the opposite layers. These results lay the foundation for exploiting the interlayer exciton in future 2D heterostructure optoelectronic devices.

  16. Commissioning of inline ECE system within waveguide based ECRH transmission systems on ASDEX upgrade

    Directory of Open Access Journals (Sweden)

    Donné A.J.H.


    Full Text Available A CW capable inline electron cyclotron emission (ECE separation system for feedback control, featuring oversized corrugated waveguides, is commissioned on ASDEX upgrade (AUG. The system is based on a combination of a polarization independent, non-resonant, Mach-Zehnder diplexer equipped with dielectric plate beam splitters [2, 3] employed as corrugated oversized waveguide filter, and a resonant Fast Directional Switch, FADIS [4, 5, 6, 7] as ECE/ECCD separation system. This paper presents an overview of the system, the low power characterisation tests and first high power commissioning on AUG.

  17. Phase-coupled plasmon-induced transparency in integrated metal-dielectric-graphene-dielectric waveguide (United States)

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


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

  18. Evanescent channels and scattering in cylindrical nanowire heterostructures (United States)

    Racec, P. N.; Racec, E. R.; Neidhardt, H.


    We investigate the scattering phenomena produced by a general finite-range nonseparable potential in a multichannel two-probe cylindrical nanowire heterostructure. The multichannel current scattering matrix is efficiently computed using the R -matrix formalism extended for cylindrical coordinates. Considering the contribution of the evanescent channels to the scattering matrix, we are able to put in evidence the specific dips in the tunneling coefficient in the case of an attractive potential. The cylindrical symmetry cancels the “selection rules” known for Cartesian coordinates. If the attractive potential is superposed over a nonuniform potential along the nanowire then resonant transmission peaks appear. We can characterize them quantitatively through the poles of the current scattering matrix. Detailed maps of the localization probability density sustain the physical interpretation of the resonances (dips and peaks). Our formalism is applied to a variety of model systems such as a quantum dot, a core/shell quantum ring, or a double barrier embedded into the nanocylinder.

  19. Characterizing the attenuation of coaxial and rectangular microwave-frequency waveguides at cryogenic temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Kurpiers, Philipp; Walter, Theodore; Magnard, Paul; Salathe, Yves; Wallraff, Andreas [ETH Zuerich, Department of Physics, Zuerich (Switzerland)


    Low-loss waveguides are required for quantum communication at distances beyond the chip-scale for any low-temperature solid-state implementation of quantum information processors. We measure and analyze the attenuation constant of commercially available microwave-frequency waveguides down to millikelvin temperatures and single photon levels. More specifically, we characterize the frequency-dependent loss of a range of coaxial and rectangular microwave waveguides down to 0.005 dB/m using a resonant-cavity technique. We study the loss tangent and relative permittivity of commonly used dielectric waveguide materials by measurements of the internal quality factors and their comparison with established loss models. The results of our characterization are relevant for accurately predicting the signal levels at the input of cryogenic devices, for reducing the loss in any detection chain, and for estimating the heat load induced by signal dissipation in cryogenic systems. (orig.)

  20. EUO-Based Multifunctional Heterostructures (United States)


    MULTIFUNCTIONAL HETEROSTRUCTURES Final Report (June, 2015) 5 5 A. Melville, T. Mairoser, A. Schmehl, D.E. Shai, E.J. Monkman, J.W. Harter , T. Heeg...Europium Oxide,” J. Appl. Phys. 109 (2011) 07C309. 13 D.E. Shai, A.J. Melville, J.W. Harter , E.J. Monkman, D.W. Shen, A. Schmehl, D.G. Schlom, and...A. Schmehl, D.E. Shai, E.J. Monkman, J.W. Harter , T. Heeg, B. Holländer, J. Schubert, K.M. Shen, J. Mannhart, and D.G. Schlom, “Lutetium-doped EuO

  1. Integration of a waveguide self-electrooptic effect device and a vertically coupled interconnect waveguide (United States)

    Vawter, G Allen [Corrales, NM


    A self-electrooptic effect device ("SEED") is integrated with waveguide interconnects through the use of vertical directional couplers. Light initially propagating in the interconnect waveguide is vertically coupled to the active waveguide layer of the SEED and, if the SEED is in the transparent state, the light is coupled back to the interconnect waveguide.

  2. Empirical model for the waveguiding properties of directly UV written waveguides

    DEFF Research Database (Denmark)

    Leick, Lasse; Harpøth, Anders; Svalgaard, Mikael


    We present an empirical model for the waveguiding properties of directly UV-written planar waveguides in silica-on-silicon. The waveguides are described by a rectangular core step-index profile, in which model parameters are found by comparison of the measured waveguide width and effective index...

  3. Miniaturized Waveguide Fourier Transform Spectrometer Project (United States)

    National Aeronautics and Space Administration — To characterize the IR optical properties of the metal-coated hollow waveguide ensemble; configure the Hollow Waveguide FTS (HWFTS) chip in such a way that we...

  4. Integrated waveguide amplifiers for optical backplanes

    NARCIS (Netherlands)

    Yang, J.; Lamprecht, T.; Worhoff, Kerstin; Driessen, A.; Horst, F.; Horst, F.; Offrein, B.J.; Offrein, B.J.; Ay, F.; Pollnau, Markus

    Amplifier performance of Nd3+-doped polymer and Al2O3 channel waveguides at 880 nm is investigated. Tapered amplifiers are embedded between optical backplane waveguides, and a maximum 0.21 dB net gain is demonstrated.

  5. Nonlinear digital out-of-plane waveguide coupler based on nonlinear scattering of a single graphene layer (United States)

    Asadi, Reza; Ouyang, Zhengbiao


    A new mechanism for out-of-plane coupling into a waveguide is presented and numerically studied based on nonlinear scattering of a single nano-scale Graphene layer inside the waveguide. In this mechanism, the refractive index nonlinearity of Graphene and nonhomogeneous light intensity distribution occurred due to the interference between the out-of-plane incident pump light and the waveguide mode provide a virtual grating inside the waveguide, coupling the out-of-plane pump light into the waveguide. It has been shown that the coupling efficiency has two distinct values with high contrast around a threshold pump intensity, providing suitable condition for digital optical applications. The structure operates at a resonance mode due to band edge effect, which enhances the nonlinearity and decreases the required threshold intensity.

  6. Refractive index biosensor using sidewall gratings in dual-slot waveguide (United States)

    Sahu, Sourabh; Ali, Jalil; Singh, Ghanshyam


    This paper presents an optical biosensor using sidewall grating in dual slot waveguide, modeled on silicon-on-insulator (SOI) platform. By optimizing the geometric parameters of the device, the spectral response is tailored to obtain a sharp resonant peak with high transmissivity that also enhances the limit-of-detection. The device detects the shift in resonant wavelength on a variation of the biomaterial refractive index. The simulation study has performed using the transfer matrix method. The obtained characteristics of the sensors include linear response to a change in refractive index of biomaterial, limit of detection of the order of 10-6 and ease of fabrication. The device performance has also compared with other SOI resonator structures like photonic crystal waveguide, sub-wavelength grating, ring resonator and grating resonator.

  7. Coupled mode theory of periodic waveguides arrays

    DEFF Research Database (Denmark)

    Lavrinenko, Andrei; Chigrin, Dmitry N.

    We apply the scalar coupled mode theory to the case of waveguides array consisting om two periodic waveguides. One of the waveguides is arbitrary shifted along another. A longitudinal shift acts as a parameter in the coupled mode theory. The proposed theory explains peculiarities of modes dispers...... dispersion and transmission in coupled periodic waveguides systems. Analytical results are compared with the numerical ones obtained by the plane wave expansion and FDTD methods....

  8. Bending loss of terahertz pipe waveguides. (United States)

    Lu, Jen-Tang; Hsueh, Yu-Chun; Huang, Yu-Ru; Hwang, Yuh-Jing; Sun, Chi-Kuang


    We present an experimental study on the bending loss of terahertz (THz) pipe waveguide. Bending loss of pipe waveguides is investigated for various frequencies, polarizations, core diameters, cladding thicknesses, and cladding materials. Our results indicate that the pipe waveguides with lower guiding loss suffer lower bending loss due to stronger mode confinement. The unexpected low bending loss in the investigated simple leaky waveguide structure promises variety of flexible applications.

  9. Slotted Polyimide-Aerogel-Filled-Waveguide Arrays (United States)

    Rodriguez-Solis, Rafael A.; Pacheco, Hector L.; Miranda, Felix A.; Meador, Mary Ann B.


    This presentation discussed the potential advantages of developing Slotted Waveguide Arrays using polyimide aerogels. Polyimide (PI) aerogels offer great promise as an enabling technology for lightweight aerospace antenna systems. PI aerogels are highly porous solids possessing low density and low dielectric permittivity combined with good mechanical properties. For slotted waveguide array applications, there are significant advantages in mass that more than compensate for the slightly higher loss of the aerogel filled waveguide when compared to state of practice commercial waveguide.

  10. Investigation of semiconductor clad optical waveguides (United States)

    Batchman, T. E.; Carson, R. F.


    A variety of techniques have been proposed for fabricating integrated optical devices using semiconductors, lithium niobate, and glasses as waveguides and substrates. The use of glass waveguides and their interaction with thin semiconductor cladding layers was studied. Though the interactions of these multilayer waveguide structures have been analyzed here using glass, they may be applicable to other types of materials as well. The primary reason for using glass is that it provides a simple, inexpensive way to construct waveguides and devices.

  11. Observation of electromagnetically induced transparency-like transmission in terahertz asymmetric waveguide-cavities systems. (United States)

    Chen, Lin; Gao, Chunmei; Xu, Jiaming; Zang, Xiaofei; Cai, Bin; Zhu, Yiming


    Electromagnetically induced transparency (EIT)-like transmission was demonstrated in terahertz asymmetric parallel plate waveguides with two identical cavities. By shifting the position of the bottom cavity from the symmetric position in the propagation direction, both the phases of the propagating wave at resonances and the coupling strengths between two cavities are changed, resulting in exciting the additional asymmetric resonance and manipulating the detuning of two different resonant frequencies. The transparent peak between two resonances comes from the cancelation of symmetric and asymmetric resonances. We also use the physical picture of excitation of quasi-dark mode to explain this EIT-like transmission, which is similar to the metamaterial systems.

  12. Competition and evolution of dielectric waveguide mode and plasmonic waveguide mode (United States)

    Yuan, Sheng-Nan; Fang, Yun-Tuan


    In order to study the coupling and evolution law of the waveguide mode and two plasmonic surface modes, we construct a line defect waveguide based on hexagonal honeycomb plasmonic photonic crystal. Through adjusting the radius of the edge dielectric rods, the competition and evolution behaviors occur between dielectric waveguide mode and plasmonic waveguide mode. There are three status: only plasmonic waveguide modes occur for rA 0.25a; two kinds of modes coexist for 0.09a slow light.

  13. Numerical Study of Opto-Fluidic Ring Resonators for Biosensor Applications

    Directory of Open Access Journals (Sweden)

    Han Keun Cho


    Full Text Available 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.

  14. Stabilized thin film heterostructure for electrochemical applications

    DEFF Research Database (Denmark)


    The invention provides a method for the formation of a thin film multi-layered heterostructure upon a substrate, said method comprising the steps of: a. providing a substrate; b. depositing a buffer layer upon said substrate, said buffer layer being a layer of stable ionic conductor (B); c...... or less; and e. repeating steps b. and c. a total of N times, such that N repeating pairs of layers (A/B) are built up, wherein N is 1 or more. The invention also provides a thin film multi-layered heterostructure as such, and the combination of a thin film multi-layered heterostructure and a substrate...

  15. Two-Dimentional Photonic Crystal Waveguides

    DEFF Research Database (Denmark)

    Søndergaard, Thomas; Dridi, Kim


    and a finite-difference-time-domain (FDTD) method. Design parameters, i.e. dielectric constants, rod diameter and waveguide width, where these waveguides are single-moded and multi-moded will be given. We will also show our recent results regarding the energy-flow (the Poynting vector) in these waveguides...

  16. Plasmonic waveguides cladded by hyperbolic metamaterials

    DEFF Research Database (Denmark)

    Ishii, Satoshi; Shalaginov, Mikhail Y.; Babicheva, Viktoriia E.


    Strongly anisotropic media with hyperbolic dispersion can be used for claddings of plasmonic waveguides (PWs). In order to analyze the fundamental properties of such waveguides, we analytically study 1D waveguides arranged from a hyperbolic metamaterial (HMM) in a HMM-Insulator-HMM (HIH) structure...

  17. Design and characterization of a novel diamond resonator


    Maricar, Mohamed Ismaeel; Glover, James; Evans, Gwynne; Khalid, Ata-ul-Habib; Cumming, David; Oxley, Chris


    In this article, the resonant frequency and quality factor of a novel coplanar waveguide (cpw) diamond-shaped resonator were analyzed using advanced design system-2009 momentum model software. The diamond resonator was compared with the cpw radial stub resonator on gallium arsenide (GaAs); the work indicated that the diamond resonator had a smaller physical size and higher quality factor (Q) at millimetric wave frequencies. Experimentally measured diamond cpw resonators fabricated on GaAs wer...

  18. Guidelines for designing 2D and 3D plasmonic stub resonators

    CERN Document Server

    Naghizadeh, Solmaz


    In this work we compare the performance of plasmonic waveguide integrated stub resonators based on 2D metal-dielectric-metal (MDM) and 3D slot-waveguide (SWG) geometries. We show that scattering matrix theory can be extended to 3D devices, and by employing scattering matrix theory we provide the guidelines for designing plasmonic 2D and 3D single-stub and double-stub resonators with a desired spectral response at the design wavelength. We provide transmission maps of 2D and 3D double-stub resonators versus stub lengths, and we specify the different regions on these maps that result in a minimum, a maximum or a plasmonically induced transparency (PIT) shape in the transmission spectrum. Radiation loss from waveguide terminations leads to a degradation of the 3D slot-waveguide based resonators. We illustrate improved waveguide terminations that boost resonator properties. We verify our results with 3D FDTD simulations.

  19. Particle acceleration by stimulated emission of radiation in cylindrical waveguide (United States)

    Tian, Xiu-Fang; Wu, Cong-Feng; Jia, Qi-Ka


    In particle acceleration by stimulated emission of radiation (PASER), efficient interaction occurs when a train of micro-bunches has periodicity identical to the resonance frequency of the medium. Previous theoretical calculations based on the simplified model have only considered the energy exchange in the boundless condition. Under experimental conditions, however, the gas active medium must be guided by the metal waveguide. In this paper, we have developed a model of the energy exchange between a train of micro-bunches and a gas mixture active medium in a waveguide boundary for the first time, based on the theory of electromagnetic fields, and made detailed analysis and calculations with MathCAD. The results show that energy density can be optimized to a certain value to get the maximum energy exchange. Supported by National Natural Science Foundation of China (10675116) and Major State Basic Research Development Programme of China (2011CB808301)

  20. Design of dual-band bandpass coplanar waveguide filter (United States)

    Omar, A. A.; Abu Safia, O. H.; Scardelletti, M. C.


    Several recent applications in communications require filters that can operate in two or more frequency bands. The aim of this article is to exploit the advantages of coplanar waveguides (CPWs) to design a dual-band bandpass coplanar waveguide filter (DBBPF). Starting from the prototype of a two pole Chebyshev low pass filter, two frequency transformations are applied to generate the DBBPF's lumped equivalent circuit. These circuits are then implemented using compact CPW series-connected resonators patterned in the centre conductor. The designed filter operates at the two frequency bands centred at 1.7 GHz and 2.7 GHz. Measured results are obtained and compared to HFSS-simulated results with very good agreement.

  1. Electrically tunable switching based on photonic-crystal waveguide loaded graphene stacks (United States)

    Liu, Hanqing; Liu, Peiguo; Bian, Li-an; Liu, Chenxi; Zhou, Qihui; Dong, Yanfei


    Through applying gate voltage to tune the chemical potential of graphene, the relative permittivity of multilayer graphene/Al2O3 stack can be dynamically adjusted over a wide range. In this paper, we mainly design novel photonic-crystal waveguides based on graphene stacks including a side-coupled waveguide with two defect cavities as well as a two-channel multiport waveguide, and aim to modulate the propagation of incident light wave via controlling the permittivity of graphene stack. It is demonstrated according to simulations that tunable switching property can be achieved in our proposed structures, such as blue shift of resonant stopband, adjustable coupled-resonator-induced transparency, and tunability of output quantity. These results could be very instructive for the potential applications in high-density integrated optical devices, photoelectric transducer, and laser pulse limiters.

  2. An on-chip polarization splitter based on the radiation loss in the bending hybrid plasmonic waveguide structure (United States)

    Sun, Chengwei; Rong, Kexiu; Gan, Fengyuan; Chu, Saisai; Gong, Qihuang; Chen, Jianjun


    Polarization beam splitters (PBSs) are one of the key components in the integrated photonic circuits. To increase the integration density, various complex hybrid plasmonic structures have been numerically designed to shrink the footprints of the PBSs. Here, to decrease the complexity of the small hybrid structures and the difficulty of the hybrid micro-nano fabrications, the radiation losses are utilized to experimentally demonstrate an ultra-small, broadband, and efficient PBS in a simple bending hybrid plasmonic waveguide structure. The hybrid plasmonic waveguide comprising a dielectric strip on the metal surface supports both the transverse-magnetic (TM) and transverse-electric (TE) waveguide modes. Because of the different field confinements, the TE waveguide mode has larger radiation loss than the TM waveguide mode in the bending hybrid strip waveguide. Based on the different radiation losses, the two incident waveguide modes of orthogonal polarization states are efficiently split in the proposed structure with a footprint of only about 2.2 × 2.2 μm2 on chips. Since there is no resonance or interference in the splitting process, the operation bandwidth is as broad as Δλ = 70 nm. Moreover, the utilization of the strongly confined waveguide modes instead of the bulk free-space light (with the spot size of at least a few wavelengths) as the incident source considerably increases the coupling efficiency, resulting in a low insertion loss of <3 dB.

  3. Coupled nanopillar waveguides: optical properties and applications

    DEFF Research Database (Denmark)

    Chigrin, Dmitry N.; Zhukovsky, Sergei V.; Lavrinenko, Andrei


    , while guided modes dispersion is strongly affected by the waveguide structure. We present a systematic analysis of the optical properties of coupled nanopillar waveguides and discuss their possible applications for integrated optics. (C) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim......In this paper we review basic properties of coupled periodic and aperiodic nanopillar waveguides. A coupled nanopillar waveguide consists of several rows of periodically or aperiodically placed dielectric rods (pillars). In such a waveguide, light confinement is due to the total internal reflection...

  4. Propagation of ELF Radiation from RS-LC System and Red Sprites in Earth-Ionosphere Waveguide

    Directory of Open Access Journals (Sweden)

    M. K. Paras


    Full Text Available In this paper, two different mechanisms return stroke-lateral corona (RS-LC system and red sprites which excite Earth-ionosphere waveguide have been discussed. The electric and magnetic fields from RS-LC system and red spites in the Earth-ionosphere waveguide have been calculated. It has been found that red sprites contribute to the Schumann resonances (SR greatly as compared to the RS-LC system.

  5. Gain-assisted Superluminal Propagation in Coupled Optical Resonators (United States)

    Chang, Hongrok; Smith, David D.


    We predict transparent superluminal pulse propagation in co-resonant coupled optical resonators, when a gain element is placed in the resonator closest to the excitation waveguide, provided the structure is over-coupled, but the resonator farthest from the excitation waveguide is under-coupled sufficiently to avoid lasing at the split modes. The effective steady-state absorptive and dispersive response of coupled resonators is derived, and the coupled-mode approximation is used to determine the conditions for transparent superluminal pulse propagation in these systems.

  6. Qualitative analysis of gain spectra of InGaAlAs/InP lasing nano-heterostructure (United States)

    Lal, Pyare; Yadav, Rashmi; Sharma, Meha; Rahman, F.; Dalela, S.; Alvi, P. A.


    This paper deals with the studies of lasing characteristics along with the gain spectra of compressively strained and step SCH based In0.71Ga0.21Al0.08As/InP lasing nano-heterostructure within TE polarization mode, taking into account the variation in well width of the single quantum well of the nano-heterostructure. In addition, the compressive conduction and valence bands dispersion profiles for quantum well of the material composition In0.71Ga0.21Al0.08As at temperature 300 K and strain 1.12% have been studied using 4 × 4 Luttinger Hamiltonian. For the proposed nano-heterostructure, the quantum well width dependence of differential gain, refractive index change and relaxation oscillation frequency with current density have been studied. Moreover, the G-J characteristics of the nano-heterostructure at different well widths have also been investigated, that provided significant information about threshold current density, threshold gain and transparency current density. The results obtained in the study of nano-heterostructure suggest that the gain and relaxation oscillation frequency both are decreased with increasing quantum well width but the required lasing wavelength is found to shift towards higher values. On behalf of qualitative analysis of the structure, the well width of 6 nm is found more suitable for lasing action at the wavelength of 1.55 μm due to minimum optical attenuation and minimum dispersion within the waveguide. The results achieved are, therefore, very important in the emerging area of nano-optoelectronics.

  7. Polymeric slot waveguide for photonics sensing (United States)

    Chovan, J.; Uherek, F.


    Polymeric slot waveguide for photonics sensing was designed, simulated and studied in this work. The polymeric slot waveguide was designed on commercial Ormocer polymer platform and operates at visible 632.8 nm wavelength. Designed polymeric slot waveguide detects the refractive index change of the ambient material by evanescent field label-free techniques. The motivation for the reported work was to design a low-cost polymeric slot waveguide for sensing arms of integrated Mach-Zehnder interferometer optical sensor with reduced temperature dependency. The minimal dimensions of advanced sensing slot waveguide structure were designed for researcher direct laser writing fabrication by nonlinear two-photon polymerization. The normalized effective refractive index changes of TE and TM fundamental modes in polymeric slot waveguide and slab waveguides were compared. The sensitivity of the normalized effective refractive index changes of TE and TM fundamental modes on refractive index changes of the ambient material was investigated by glucose-water solutions.

  8. Quantum waveguides with corners

    Directory of Open Access Journals (Sweden)

    Raymond Nicolas


    Full Text Available The simplest modeling of planar quantum waveguides is the Dirichlet eigenproblem for the Laplace operator in unbounded open sets which are uniformly thin in one direction. Here we consider V-shaped guides. Their spectral properties depend essentially on a sole parameter, the opening of the V. The free energy band is a semi-infinite interval bounded from below. As soon as the V is not flat, there are bound states below the free energy band. There are a finite number of them, depending on the opening. This number tends to infinity as the opening tends to 0 (sharply bent V. In this situation, the eigenfunctions concentrate and become self-similar. In contrast, when the opening gets large (almost flat V, the eigenfunctions spread and enjoy a different self-similar structure. We explain all these facts and illustrate them by numerical simulations. La modélisation la plus simple des guides d’ondes quantiques plans est le problème aux valeurs propres pour le laplacien dans des ouverts non bornés qui sont fins dans une direction. Ici nous considérons des guides en forme de V. Leurs propriétés spectrales dépendent essentiellement d’un seul paramètre, l’ouverture du V. La bande d’énergie libre est un intervalle semi-infini borné inférieurement. Dès que le V n’est pas plat, il existe des états liés sous la bande d’énergie libre. Ils sont en nombre fini, fonction de l’ouverture. Ce nombre tend vers l’infini quand l’ouverture tend vers 0 (V très refermé. Dans cette situation, les fonctions propres se concentrent et deviennent auto-similaires. À l’opposé, quand l’ouverture est grande (V très aplati, les fonctions propres s’étalent et jouissent d’une autre structure auto-similaire. Nous expliquons tous ces résultats et les illustrons par des expériences numériques.

  9. Light propagation characteristics through the annular coupled-cavity waveguides based on the two-dimensional square-lattice photonic crystal (United States)

    Feng, Shuai; Li, Yu-xi; Ao, Ling; Ren, Cheng


    The light propagation characteristics through the annular coupled-resonator cavity waveguides are systematically analyzed by the finite-difference time-domain (FDTD) method. It is found that this kind of waveguide has more minbands owing to the increasing of the cavity's size, compared with the traditional line-typed coupled-resonator waveguide. The group velocity of light propagation can be reduced for a further degree when the adjacent annular cavities are interlaced in the perpendicular direction, and a group velocity about 0.00067 c ( c is the light speed in vacuum) can be obtained.

  10. Photonic-crystal waveguide biosensor

    DEFF Research Database (Denmark)

    Skivesen, Nina; Têtu, Amélie; Kristensen, Martin


    A photonic-crystal waveguide sensor is presented for biosensing. The sensor is applied for refractive index measurements and detection of protein-concentrations. Concentrations around 10 μg/ml (0.15μMolar) are measured with excellent signal to noise ratio, and a broad, dynamic refractive index se...

  11. Glass Waveguides for Periodic Poling

    DEFF Research Database (Denmark)

    Fage-Pedersen, Jacob; Jacobsen, Rune Shim; Kristensen, Martin


    Planar silica-based waveguide devices have been developed for second-harmonic generation by poling with periodic electrodes. We show that detrimental charge transport can occur along interfaces, but with proper choice of fabrication, high-quality devices are obtained....

  12. Tuning ZOR in ENZ waveguide using a single longitudinal slot and equivalent circuit parameter extraction

    DEFF Research Database (Denmark)

    Vojnovic, Nebojsa; Jokanovic, Branka; Mitrovic, Miranda


    In this paper, the effects of placing a longitudinal slot in the channel region of a rectangular waveguide ENZ structure, are analyzed. A following investigation showed that changing the length of this slot can be employed to achieve tuning of only the tunneling frequency. Maximum resonant freque...

  13. Mapping the broadband polarization properties of linear 2D SOI photonic crystal waveguides

    DEFF Research Database (Denmark)

    Canning, John; Skivesen, Nina; Kristensen, Martin


    Both quasi-TE and TM polarisation spectra for a silicon- on-insulator (SOI) waveguide are recorded over (1100-1700) nm using a broadband supercontinuum source. By studying both the input and output polarisation eigenstates we observe narrowband resonant cross coupling near the lowest quasi-TE mode...

  14. Commissioning of inline ECE system within waveguide based ECRH transmission systems on ASDEX upgrade

    DEFF Research Database (Denmark)

    Bongers, W. A.; Kasparek, W.; Doelman, N.


    with dielectric plate beam splitters [2, 3] employed as corrugated oversized waveguide filter, and a resonant Fast Directional Switch, FADIS [4, 5, 6, 7] as ECE/ECCD separation system. This paper presents an overview of the system, the low power characterisation tests and first high power commissioning on AUG....

  15. Geometry and transport in a model of two coupled quadratic nonlinear waveguides

    DEFF Research Database (Denmark)

    Stirling, James R.; Bang, Ole; Christiansen, Peter Leth


    a specific input and range of material properties. We show how these barriers break down as the coupling between the waveguides is increased and what the role of resonances in the phase space has in this. We also show how an increase in the coupling can lead to chaos and global transport and what effect...

  16. Dielectric Engineering of Electronic Correlations in a van der Waals Heterostructure. (United States)

    Steinleitner, Philipp; Merkl, Philipp; Graf, Alexander; Nagler, Philipp; Watanabe, Kenji; Taniguchi, Takashi; Zipfel, Jonas; Schüller, Christian; Korn, Tobias; Chernikov, Alexey; Brem, Samuel; Selig, Malte; Berghäuser, Gunnar; Malic, Ermin; Huber, Rupert


    Heterostructures of van der Waals bonded layered materials offer unique means to tailor dielectric screening with atomic-layer precision, opening a fertile field of fundamental research. The optical analyses used so far have relied on interband spectroscopy. Here we demonstrate how a capping layer of hexagonal boron nitride (hBN) renormalizes the internal structure of excitons in a WSe 2 monolayer using intraband transitions. Ultrabroadband terahertz probes sensitively map out the full complex-valued mid-infrared conductivity of the heterostructure after optical injection of 1s A excitons. This approach allows us to trace the energies and line widths of the atom-like 1s-2p transition of optically bright and dark excitons as well as the densities of these quasiparticles. The excitonic resonance red shifts and narrows in the WSe 2 /hBN heterostructure compared to the bare monolayer. Furthermore, the ultrafast temporal evolution of the mid-infrared response function evidences the formation of optically dark excitons from an initial bright population. Our results provide key insight into the effect of nonlocal screening on electron-hole correlations and open new possibilities of dielectric engineering of van der Waals heterostructures.

  17. Glass-embedded two-dimensional silicon photonic crystal devices with a broad bandwidth waveguide and a high quality nanocavity. (United States)

    Jeon, Seung-Woo; Han, Jin-Kyu; Song, Bong-Shik; Noda, Susumu


    To enhance the mechanical stability of a two-dimensional photonic crystal slab structure and maintain its excellent performance, we designed a glass-embedded silicon photonic crystal device consisting of a broad bandwidth waveguide and a nanocavity with a high quality (Q) factor, and then fabricated the structure using spin-on glass (SOG). Furthermore, we showed that the refractive index of the SOG could be tuned from 1.37 to 1.57 by varying the curing temperature of the SOG. Finally, we demonstrated a glass-embedded heterostructured cavity with an ultrahigh Q factor of 160,000 by adjusting the refractive index of the SOG.

  18. Transmission Characteristics of Hybrid Modes in Corrugated Waveguides Above the Bragg Frequency (United States)

    Ohkubo, Kunizo; Saito, Teruo; Yamaguchi, Yuusuke; Tatematsu, Yoshinori; Kasa, Jun; Kubo, Shin; Shimozuma, Takashi; Tanaka, Kenji; Nishiura, Masaki


    We studied the transmission characteristics of hybrid modes in a corrugated circular waveguide above the Bragg frequency to develop a broad-band transmission line for millimeter waves. Millimeter waves at 294 GHz were transmitted into a straight waveguide. From observed power profiles in waveguide cross-sections, a high attenuation rate of 0.13 dB/m was obtained. To match a theoretical attenuation constant with the experimental one, we introduced an ad hoc coefficient of conventional surface reactance in the waveguide wall. This was necessary because the wall began to look like the surface with a decreasing anisotropic reactance owing to the frequency above the Bragg frequency. Using nonlinear optimization for mode content analysis, the observed power profiles in the waveguide cross-section were matched with theoretical profiles. There was good agreement between the calculated and observed centers of power profiles and attenuation rate along the waveguide. The theoretical analysis showed that the magnetic field at the waveguide wall increases and the substantial attenuation takes place. Above the Bragg frequency coupling to backwards propagating modes is a point of consideration. A combination of the backwards propagating EH1,26 and the forward propagating HE11 modes satisfied the Bragg condition at 294.7 GHz which was the nearest frequency of operating frequency. A strong attenuation of the incoming HE11 mode by Bragg resonance was not expected due to large difference of 0.7 GHz. It becomes clear that the observed high transmission loss outside of the Bragg resonance can be explained by a decrease in anisotropic surface reactance at the wall.

  19. Dissipationless transport of spin-polarized electrons and Cooper pairs in an electron waveguide (United States)

    Levy, J.; Annadi, A.; Lu, S.; Cheng, G.; Tylan-Tyler, A.; Briggeman, M.; Tomczyk, M.; Huang, M.; Pekker, D.; Irvin, P.; Lee, H.; Lee, J.-W.; Eom, C.-B.

    Electron systems undergo profound changes in their behavior when constrained to move along a single axis. To date, clean one-dimensional (1D) electron transport has only been observed in carbon-based nanotubes and nanoribbons, and compound semiconductor nanowires. Complex-oxide heterostructures can possess conductive two-dimensional (2D) interfaces with much richer chemistries and properties, e.g., superconductivity, but with mobilities that appear to preclude ballistic transport in 1D. Here we show that nearly ideal 1D electron waveguides exhibiting ballistic transport of electrons and non-superconducting Cooper pairs can be formed at the interface between the two band insulators LaAlO3 and SrTiO3. The electron waveguides possess gate and magnetic-field selectable spin and charge degrees of freedom, and can be tuned to the one-dimensional limit of a single spin-polarized quantum channel. The strong attractive electron-electron interactions enable a new mode of dissipationless transport of electron pairs that is not superconducting. The selectable spin and subband quantum numbers of these electron waveguides may be useful for quantum simulation, quantum informatio We gratefully acknowledge financial support from ONR N00014-15-1-2847 (JL), AFOSR (FA9550-15-1-0334 (CBE) and FA9550-12-1-0057 (JL, CBE)), AOARD FA2386-15-1-4046 (CBE) and NSF (DMR-1104191 (JL), DMR-1124131 (CBE, JL) and DMR-1234096 (CBE)).

  20. Finite Ground Coplanar (FGC) Waveguide: Characteristics and Advantages Evaluated for Radiofrequency and Wireless Communication Circuits (United States)

    Ponchak, George E.


    Researchers in NASA Lewis Research Center s Electron Device Technology Branch are developing transmission lines for radiofrequency and wireless circuits that are more efficient, smaller, and make lower cost circuits possible. Traditionally, radiofrequency and wireless circuits have employed a microstrip or coplanar waveguide to interconnect the various electrical elements that comprise a circuit. Although a coplanar waveguide (CPW) is widely viewed as better than a microstrip for most applications, it too has problems. To solve these problems, NASA Lewis and the University of Michigan developed a new version of a coplanar waveguide with electrically narrow ground planes. Through extensive numerical modeling and experimental measurements, we have characterized the propagation constant of the FGC waveguide, the lumped and distributed circuit elements integrated in the FGC waveguide, and the coupling between parallel transmission lines. Although the attenuation per unit length is higher for the FGC waveguide because of higher conductor loss, the attenuation is comparable when the ground plane width is twice the center conductor width as shown in the following graph. An upper limit to the line width is derived from observations that when the total line width is greater than ld/2, spurious resonances due to the parallel plate waveguide mode are established. Thus, the ground plane width must be less than ld/4 where ld is the wavelength in the dielectric. Since the center conductor width S is typically less than l/10 to maintain good transverse electromagnetic mode characteristics, it follows that a ground plane width of B = 2S would also be electrically narrow. Thus, we can now treat the ground strips of the FGC waveguide the same way that the center conductor is treated.

  1. Experimental study of the kinetic inductance fraction of superconducting coplanar waveguide

    Energy Technology Data Exchange (ETDEWEB)

    Gao, J. [California Institute of Technology, Pasadena, CA 91125 (United States)]. E-mail:; Zmuidzinas, J. [California Institute of Technology, Pasadena, CA 91125 (United States); Mazin, B.A. [Jet Propulsion Lab, Pasadena, CA 91107 (United States); Day, P.K. [Jet Propulsion Lab, Pasadena, CA 91107 (United States); Leduc, H.G. [Jet Propulsion Lab, Pasadena, CA 91107 (United States)


    We have studied the kinetic inductance fraction (ratio of kinetic inductance to total inductance) of superconducting coplanar waveguides (CPWs) by measuring the resonance frequency of CPW transmission line resonators. We describe a procedure for accurately determining the kinetic inductance of transmission line geometries with small kinetic inductance fractions. In this approach, we compare the temperature dependence of the resonance frequency with that of a resonator of the same film thickness but with a large kinetic inductance fraction. We present data for 200 nm-thick Al CPWs of several geometries and compare that with our own calculations and with calculations found in literature.

  2. Vertical-Cavity In-plane Heterostructures: Physics and Applications

    DEFF Research Database (Denmark)

    Taghizadeh, Alireza; Mørk, Jesper; Chung, Il-Sug


    We show that the in-plane heterostructures realized in vertical cavities with high contrast grating(HCG) reflector enables exotic configurations of heterostructure and photonic wells. In photonic crystal heterostructures forming a photonic well, the property of a confined mode is determined by th...... to discuss the rich potential of this heterostructure as a platform for various physics studies and propose a system of two laterally coupled cavities which shows the breaking of parity-time symmetry as an example....

  3. The exciton excitations and relaxation processes in low-dimensional semiconductor heterostructures with quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Aleshkin, V. Ya.; Gavrilenko, L. V.; Gaponova, D. M., E-mail:; Krasil’nik, Z. F.; Kryzhkov, D. I. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation)


    The processes associated with the transfer of excitonic excitations between tunnel-uncoupled quantum wells (QW) and the influence of the local electric field were investigated in AlGaAs/GaAs heterostructures by the method of photoluminescence excitation (PLE) spectroscopy at low (4.2 K) temperature. The variation in the intensity of photoluminescence (PL) from the wider QW under resonant excitation of excitonic transition in the adjacent narrow QW has been observed. The difference in the PL maximum position and intensity of the wider QW under resonance excitation of the narrow one is explained by the influence of quantum-confined Stark effect on the process of exciton recombination.

  4. Electromagnetic Scattering at the Waveguide Step between Equilateral Triangular Waveguides

    Directory of Open Access Journals (Sweden)

    Ana Morán-López


    Full Text Available The analysis of the electromagnetic scattering at discontinuities between equilateral triangular waveguides is studied. The complete electromagnetic solution is derived using analytical closed form expressions for the mode spectrum of the equilateral waveguide. The mathematical formulation of the electromagnetic scattering problem is based on the quasi-analytical Mode-Matching method. This method benefits from the electromagnetic field division into symmetries as well as from the plane wave formulation presented for the expressions involved. The unification of the surface integrals used in the method thanks to the plane wave formulation is revealed, leading to expressions that are very well suited for its implementation in an electromagnetic analysis and design code. The obtained results for some cases of interest (building blocks for microwave components for communication systems are verified using other numerical methods included in a commercial software package, showing the potential of the presented approach based on quasi-analytic expressions.

  5. Slab Waveguide and Optical Fibers for Novel Plasmonic Sensor Configurations. (United States)

    Cennamo, Nunzio; Mattiello, Francesco; Zeni, Luigi


    The use of plasmonic sensor devices often requires replaceable parts and disposable chips for easy, fast and on-site detection analysis. In light of these requests, we propose a novel low-cost surface plasmon resonance sensor platform for possible selective detection of analytes in aqueous solutions. It is based on a Polymethyl methacrylate (PMMA) slab waveguide with a thin gold film on the top surface inserted in a special holder, designed to produce the plasmonic resonance at the gold-dielectric interface. A wide-band light is launched in the PMMA slab waveguide through a trench realized in the holder directly, and illuminated with a PMMA plastic optical fiber (POF) to excite surface Plasmon waves. The output light is then collected by another PMMA POF kept at the end of the slab at an angle of 90° to the trench, and carried to a spectrometer. In this configuration, the trench has been used because a large incident angle is required for surface plasmon resonance excitation. The preliminary results showed that the sensor's performances make it suitable for bio-chemical applications. The easy replacement of the chip allows for the production of an engineered platform by simplifying the measurement procedures.

  6. Slab Waveguide and Optical Fibers for Novel Plasmonic Sensor Configurations (United States)

    Cennamo, Nunzio; Mattiello, Francesco; Zeni, Luigi


    The use of plasmonic sensor devices often requires replaceable parts and disposable chips for easy, fast and on-site detection analysis. In light of these requests, we propose a novel low-cost surface plasmon resonance sensor platform for possible selective detection of analytes in aqueous solutions. It is based on a Polymethyl methacrylate (PMMA) slab waveguide with a thin gold film on the top surface inserted in a special holder, designed to produce the plasmonic resonance at the gold-dielectric interface. A wide-band light is launched in the PMMA slab waveguide through a trench realized in the holder directly, and illuminated with a PMMA plastic optical fiber (POF) to excite surface Plasmon waves. The output light is then collected by another PMMA POF kept at the end of the slab at an angle of 90° to the trench, and carried to a spectrometer. In this configuration, the trench has been used because a large incident angle is required for surface plasmon resonance excitation. The preliminary results showed that the sensor’s performances make it suitable for bio-chemical applications. The easy replacement of the chip allows for the production of an engineered platform by simplifying the measurement procedures. PMID:28672796

  7. Nanoantenna couplers for metal-insulator-metal waveguide interconnects (United States)

    Onbasli, M. Cengiz; Okyay, Ali K.


    State-of-the-art copper interconnects suffer from increasing spatial power dissipation due to chip downscaling and RC delays reducing operation bandwidth. Wide bandwidth, minimized Ohmic loss, deep sub-wavelength confinement and high integration density are key features that make metal-insulator-metal waveguides (MIM) utilizing plasmonic modes attractive for applications in on-chip optical signal processing. Size-mismatch between two fundamental components (micron-size fibers and a few hundred nanometers wide waveguides) demands compact coupling methods for implementation of large scale on-chip optoelectronic device integration. Existing solutions use waveguide tapering, which requires more than 4λ-long taper distances. We demonstrate that nanoantennas can be integrated with MIM for enhancing coupling into MIM plasmonic modes. Two-dimensional finite-difference time domain simulations of antennawaveguide structures for TE and TM incident plane waves ranging from λ = 1300 to 1600 nm were done. The same MIM (100-nm-wide Ag/100-nm-wide SiO2/100-nm-wide Ag) was used for each case, while antenna dimensions were systematically varied. For nanoantennas disconnected from the MIM; field is strongly confined inside MIM-antenna gap region due to Fabry-Perot resonances. Major fraction of incident energy was not transferred into plasmonic modes. When the nanoantennas are connected to the MIM, stronger coupling is observed and E-field intensity at outer end of core is enhanced more than 70 times.

  8. FRET enhancement in aluminum zero-mode waveguides. (United States)

    de Torres, Juan; Ghenuche, Petru; Moparthi, Satish Babu; Grigoriev, Victor; Wenger, Jérôme


    Zero-mode waveguides (ZMWs) can confine light into attoliter volumes, which enables single molecule fluorescence experiments at physiological micromolar concentrations. Of the fluorescence spectroscopy techniques that can be enhanced by ZMWs, Förster resonance energy transfer (FRET) is one of the most widely used in life sciences. Combining zero-mode waveguides with FRET provides new opportunities to investigate biochemical structures or follow interaction dynamics at micromolar concentrations with single-molecule resolution. However, prior to any quantitative FRET analysis on biological samples, it is crucial to establish first the influence of the ZMW on the FRET process. Here, we quantify the FRET rates and efficiencies between individual donor-acceptor fluorophore pairs that diffuse into aluminum zero-mode waveguides. Aluminum ZMWs are important structures thanks to their commercial availability and the large amount of literature that describe their use for single-molecule fluorescence spectroscopy. We also compared the results between ZMWs milled in gold and aluminum, and found that although gold has a stronger influence on the decay rates, the lower losses of aluminum in the green spectral region provide larger fluorescence brightness enhancement factors. For both aluminum and gold ZMWs, we observed that the FRET rate scales linearly with the isolated donor decay rate and the local density of optical states. Detailed information about FRET in ZMWs unlocks their application as new devices for enhanced single-molecule FRET at physiological concentrations. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Fundamental Limitations to Gain Enhancement in Periodic Media and Waveguides

    DEFF Research Database (Denmark)

    Grgic, Jure; Ott, Johan Raunkjær; Wang, Fengwen


    modifies the underlying dispersion law, and thereby may degrade the slow-light properties underlying the device operation and the anticipated gain enhancement itself. This degradation is generic; we demonstrate it for three different systems of current interest (coupled-resonator optical waveguides, Bragg......A common strategy to compensate for losses in optical nanostructures is to add gain material in the system. By exploiting slow-light effects it is expected that the gain may be enhanced beyond its bulk value. Here we show that this route cannot be followed uncritically: inclusion of gain inevitably...

  10. A theoretical and experimental study of coplanar waveguide shunt stubs (United States)

    Dib, Nihad I.; Ponchak, George E.; Katehi, Linda P. B.


    A comprehensive theoretical and experimental study of straight and bent coplanar waveguide (CPW) shunt stubs is presented. In the theoretical analysis, the CPW is assumed to be inside a cavity while, the experiments are performed on open structures. For the analysis of CPW discontinuities with air-bridges, a hybrid technique was developed which was validated through extensive theoretical and experimental comparisons. The effect of the cavity resonances on the behavior of the stubs with and without air-bridges is investigated. In addition, the encountered radiation loss due to the discontinuities is evaluated experimentally.

  11. Design of bent waveguide semiconductor lasers using nonlinear equivalent chirp (United States)

    Li, Lianyan; Shi, Yuechun; Zhang, Yunshan; Chen, Xiangfei


    Reconstruction equivalent chirp (REC) technique is widely used in the design and fabrication of semiconductor laser arrays and tunable lasers with low cost and high wavelength accuracy. Bent waveguide is a promising method to suppress the zeroth order resonance, which is an intrinsic problem in REC technique. However, it may introduce basic grating chirp and deteriorate the single longitudinal mode (SLM) property of the laser. A nonlinear equivalent chirp pattern is proposed in this paper to compensate the grating chirp and improve the SLM property. It will benefit the realization of low-cost Distributed feedback (DFB) semiconductor laser arrays with accurate lasing wavelength.

  12. Extraction film for optical waveguide and method of producing same

    Energy Technology Data Exchange (ETDEWEB)

    Tarsa, Eric J.; Durkee, John W.


    An optical waveguide includes a waveguide body and a film disposed on a surface of the waveguide body. The film includes a base and a plurality of undercut light extraction elements disposed between the base and the surface.

  13. Analysis and experiments of a waveguide post's influence on photocathode RF gun

    Energy Technology Data Exchange (ETDEWEB)

    Qian Houjun [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China)], E-mail:; Tang Chuanxiang; Zheng Shuxin; Tong Dechun; Chen Huaibi; Huang Wenhui; Guan Xin [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China)


    Several BNL/KEK/SHI type photocathode RF guns have been fabricated for high-quality electron beams in Accelerator Laboratory of Tsinghua University. This paper describes how the characteristics of a waveguide post can be chosen to correct for a mismatch in power coupling without affecting the pi-mode resonant frequency and the balance of fields between the two cells. Microwave circuit theories are used to analyze how to select the proper location and depth of the waveguide post. The tolerance on the post positioning is evaluated based on gun field quality requirements. MAFIA simulations and RF experiments have been done to confirm the theoretical analysis.

  14. Mode conversion in metal–insulator–metal waveguide with a shifted cavity (United States)

    Wang, Yueke; Yan, Xin


    We propose a method, which is utilized to achieve the plasmonic mode conversion in metal–insulator–metal (MIM) waveguide, theoretically. Our proposed structure is composed of bus waveguides and a shifted cavity. The shifted cavity can choose out a plasmonic mode (a- or s-mode) when it is in Fabry–Perot (FP) resonance. The length of the shifted cavity L is carefully chosen, and our structure can achieve the mode conversion between a- and s-mode in the communication region. Besides, our proposed structure can also achieve plasmonic mode-division multiplexing. All the numerical simulations are carried on by the finite element method to verify our design.

  15. Metal-clad waveguide sensors

    DEFF Research Database (Denmark)

    Skivesen, Nina

    This work concerns planar optical waveguide sensors for biosensing applications, with the focus on deep-probe sensing for micron-scale biological objects like bacteria and whole cells. In the last two decades planar metal-clad waveguides have been brieflyintroduced in the literature applied...... for various biosensing applications, however a thorough study of the sensor configurations has not been presented, but is the main subject of this thesis. Optical sensors are generally well suited for bio-sensing asthey show high sensitivity and give an immediate response for minute changes in the refractive...... index of a sample, due to the high sensitivity of optical bio-sensors detection of non-labeled biological objects can be performed. The majority of opticalsensors presented in the literature and commercially available optical sensors are based on evanescent wave sensing, however most of these sensors...

  16. CLIC Waveguide Damped Accelerating Structure Studies

    CERN Document Server

    Dehler, M; Wuensch, Walter


    Studies of waveguide damped 30 GHz accelerating structures for multibunching in CLIC are described. Frequency discriminated damping using waveguides with a lowest cutoff frequency above the fundamental but below the higher order modes was considered. The wakefield behavior was investigated using time domain MAFIA computations over up to 20 cells and for frequencies up to 150 GHz. A configuration consisting of four T-cross-sectioned waveguides per cell reduces the transverse wake below 1% at typical CLIC bunch spacings.

  17. Reverse-symmetry waveguides: Theory and fabrication

    DEFF Research Database (Denmark)

    Horvath, R.; Lindvold, Lars René; Larsen, N.B.


    We present an extensive theoretical analysis of reverse-symmetry waveguides with special focus on their potential application as sensor components in aqueous media and demonstrate a novel method for fabrication of such waveguides. The principle of reverse symmetry is based on making the refractiv...... has the advantage of deeper penetration of the evanescent electromagnetic field into the cover medium, theoretically permitting higher sensitivity to analytes compared to traditional waveguide designs. We present calculated sensitivities and probing depths of conventional and reverse...

  18. Fabrication Of Fiber-Optic Waveguide Coupler (United States)

    Goss, Willis; Nelson, Mark D.; Mclauchlan, John M.


    Technique for making four-port, single-mode fiber-optic waveguide couplers requires no critically-precise fabrication operations or open-loop processes. Waveguide couplers analogous to beam-splitter prisms. Essential in many applications that require coherent separation or combination of two waves; for example, for interferometric purposes. Components of optical waveguide coupler held by paraffin on microscope slide while remaining cladding of two optical fibers fused together by arc welding.


    DEFF Research Database (Denmark)


    Planar optical waveguide comprising a core region and a cladding region comprising a photonic crystal material, said photonic crystal material having a lattice of column elements, wherein at least a number of said column elements are elongated substantially in an axial direction for said core...... region. The invention also relates to optical devices comprising planar optical waveguides and methods of making waveguides and optical devices....

  20. Terahertz semiconductor-heterostructure laser. (United States)

    Köhler, Rüdeger; Tredicucci, Alessandro; Beltram, Fabio; Beere, Harvey E; Linfield, Edmund H; Davies, A Giles; Ritchie, David A; Iotti, Rita C; Rossi, Fausto


    Semiconductor devices have become indispensable for generating electromagnetic radiation in everyday applications. Visible and infrared diode lasers are at the core of information technology, and at the other end of the spectrum, microwave and radio-frequency emitters enable wireless communications. But the terahertz region (1-10 THz; 1 THz = 10(12) Hz) between these ranges has remained largely underdeveloped, despite the identification of various possible applications--for example, chemical detection, astronomy and medical imaging. Progress in this area has been hampered by the lack of compact, low-consumption, solid-state terahertz sources. Here we report a monolithic terahertz injection laser that is based on interminiband transitions in the conduction band of a semiconductor (GaAs/AlGaAs) heterostructure. The prototype demonstrated emits a single mode at 4.4 THz, and already shows high output powers of more than 2 mW with low threshold current densities of about a few hundred A cm(-2) up to 50 K. These results are very promising for extending the present laser concept to continuous-wave and high-temperature operation, which would lead to implementation in practical photonic systems.

  1. Observing electron spin resonance between 0.1 and 67 GHz at temperatures between 50 mK and 300 K using broadband metallic coplanar waveguides

    Energy Technology Data Exchange (ETDEWEB)

    Wiemann, Yvonne; Simmendinger, Julian; Clauss, Conrad; Bogani, Lapo; Dressel, Martin; Scheffler, Marc [1. Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart (Germany); Bothner, Daniel; Koelle, Dieter; Kleiner, Reinhold [Physikalisches Institut and Center for Collective Quantum Phenomena in LISA+, Universität Tübingen, Auf der Morgenstelle 14, 72076 Tübingen (Germany)


    We describe a fully broadband approach for electron spin resonance (ESR) experiments, where it is possible to tune not only the magnetic field but also the frequency continuously over wide ranges. Here, a metallic coplanar transmission line acts as compact and versatile microwave probe that can easily be implemented in different cryogenic setups. We perform ESR measurements at frequencies between 0.1 and 67 GHz and at temperatures between 50 mK and room temperature. Three different types of samples (Cr{sup 3+} ions in ruby, organic radicals of the nitronyl-nitroxide family, and the doped semiconductor Si:P) represent different possible fields of application for the technique. We demonstrate that an extremely large phase space in temperature, magnetic field, and frequency for ESR measurements, substantially exceeding the range of conventional ESR setups, is accessible with metallic coplanar lines.

  2. Waveguide structures in anisotropic nonlinear crystals (United States)

    Li, Da; Hong, Pengda; Meissner, Helmuth E.


    We report on the design and manufacturing parameters of waveguiding structures of anisotropic nonlinear crystals that are employed for harmonic conversions, using Adhesive-Free Bonding (AFB®). This technology enables a full range of predetermined refractive index differences that are essential for the design of single mode or low-mode propagation with high efficiency in anisotropic nonlinear crystals which in turn results in compact frequency conversion systems. Examples of nonlinear optical waveguides include periodically bonded walk-off corrected nonlinear optical waveguides and periodically poled waveguide components, such as lithium triborate (LBO), beta barium borate (β-BBO), lithium niobate (LN), potassium titanyl phosphate (KTP), zinc germanium phosphide (ZGP) and silver selenogallate (AGSE). Simulation of planar LN waveguide shows that when the electric field vector E lies in the k-c plane, the power flow is directed precisely along the propagation direction, demonstrating waveguiding effect in the planar waveguide. Employment of anisotropic nonlinear optical waveguides, for example in combination with AFB® crystalline fiber waveguides (CFW), provides access to the design of a number of novel high power and high efficiency light sources spanning the range of wavelengths from deep ultraviolet (as short as 200 nm) to mid-infrared (as long as about 18 μm). To our knowledge, the technique is the only generally applicable one because most often there are no compatible cladding crystals available to nonlinear optical cores, especially not with an engineer-able refractive index difference and large mode area.

  3. Improved optical planar waveguides for lasers Project (United States)

    National Aeronautics and Space Administration — Demonstrate efficacy of a novel growth technique for planar waveguides (PWG) Enable PWG laser technology with improved performance, efficiency and manufacturability....

  4. Near-field characterization of plasmonic waveguides

    DEFF Research Database (Denmark)

    Zenin, Volodymyr


    simply by changing geometric parameters of the waveguide, keeping in mind the trade-off between confinement and propagation losses. A broad variety of plasmonic waveguides and waveguide components, including antennas for coupling the light in/out of the waveguide, requires correspondent characterization...... capabilities, especially on experimental side. The most straight-forward and powerful technique for such purpose is scanning near-field optical microscopy, which allows to probe and map near-field distribution and therefore becomes the main tool in this project. The detailed description of the used setups...

  5. High-Q photonic crystal cavities in all-semiconductor photonic crystal heterostructures (United States)

    Bushell, Z. L.; Florescu, M.; Sweeney, S. J.


    Photonic crystal cavities enable the realization of high Q-factor and low mode-volume resonators, with typical architectures consisting of a thin suspended periodically patterned layer to maximize confinement of light by strong index guiding. We investigate a heterostructure-based approach comprising a high refractive index core and lower refractive index cladding layers. While confinement typically decreases with decreasing index contrast between the core and cladding layers, we show that, counterintuitively, due to the confinement provided by the photonic band structure in the cladding layers, it becomes possible to achieve Q factors >104 with only a small refractive index contrast. This opens up opportunities for implementing high-Q factor cavities in conventional semiconductor heterostructures, with direct applications to the design of electrically pumped nanocavity lasers using conventional fabrication approaches.

  6. Effect of rare earth metal on the spin-orbit torque in magnetic heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Ueda, Kohei; Pai, Chi-Feng; Tan, Aik Jun; Mann, Maxwell; Beach, Geoffrey S. D., E-mail: [Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)


    We report the effect of the rare earth metal Gd on current-induced spin-orbit torques (SOTs) in perpendicularly magnetized Pt/Co/Gd heterostructures, characterized using harmonic measurements and spin-torque ferromagnetic resonance (ST-FMR). By varying the Gd metal layer thickness from 0 nm to 8 nm, harmonic measurements reveal a significant enhancement of the effective fields generated from the Slonczewski-like and field-like torques. ST-FMR measurements confirm an enhanced effective spin Hall angle and show a corresponding increase in the magnetic damping constant with increasing Gd thickness. These results suggest that Gd plays an active role in generating SOTs in these heterostructures. Our finding may lead to spin-orbitronics device application such as non-volatile magnetic random access memory, based on rare earth metals.

  7. Theoretical realization of dynamically tunable double plasmonically induced transparency in a graphene-based waveguide structure (United States)

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


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

  8. Practical microstructured and plasmonic terahertz waveguides (United States)

    Markov, Andrey

    The terahertz frequency range, with frequencies lying between 100 GHz and 10 THz, has strong potential for various technological and scientific applications such as sensing, imaging, communications, and spectroscopy. Most terahertz (THz) sources are immobile and THz systems use free-space propagation in dry air where losses are minimal. Designing efficient THz waveguides for flexible delivery of broadband THz radiation is an important step towards practical applications of terahertz techniques. THz waveguides can be very useful on the system integration level when used for connection of the diverse THz point devices, such as sources, filters, sensor cells, detectors, etc. The most straightforward application of waveguides is to deliver electromagnetic waves from the source to the point of detection. Cumbersome free-space optics can be replaced by waveguides operating in the THz range, which could lead to the development of compact THz time domain spectroscopy systems. Other promising applications of THz waveguides are in sensing and imaging. THz waveguides have also been shown to operate in subwavelength regimes, offering mode confinement in waveguide structures with a size smaller than the diffraction limit, and thus, surpassing the resolution of free-space THz imaging systems. In order to design efficient terahertz waveguides, the frequency dependent loss and dispersion of the waveguide must be minimized. A possible solution would be to increase the fraction of mode power propagating through air. In this thesis, the usage of planar porous air/dielectric waveguides and metal wire/dielectric hybrid terahertz fibers will be discussed. First, I present a novel design of a planar porous low-loss waveguide, describe its fabrication, and characterize it in view of its potential applications as a low-loss waveguide and sensor in the THz spectral range. The waveguide structure features a periodic sequence of layers of thin (25-50 mum) polyethylene film that are separated

  9. Optofluidic Lab-on-a-Chip Fluorescence Sensor Using Integrated Buried ARROW (bARROW) Waveguides. (United States)

    Wall, Thomas; McMurray, Johnny; Meena, Gopikrishnan; Ganjalizadeh, Vahid; Schmidt, Holger; Hawkins, Aaron R


    Optofluidic, lab-on-a-chip fluorescence sensors were fabricated using buried anti-resonant reflecting optical waveguides (bARROWs). The bARROWs are impervious to the negative water absorption effects that typically occur in waveguides made using hygroscopic, plasma-enhanced chemical vapor deposition (PECVD) oxides. These sensors were used to detect fluorescent microbeads and had an average signal-to-noise ratio (SNR) that was 81.3% higher than that of single-oxide ARROW fluorescence sensors. While the single-oxide ARROW sensors were annealed at 300 °C to drive moisture out of the waveguides, the bARROW sensors required no annealing process to obtain a high SNR.

  10. Effective Surface Plasmon Polaritons Induced by Modal Dispersion in a Waveguide (United States)

    Li, Zhuo; Liu, Liangliang; Sun, Hengyi; Sun, Yunhe; Gu, Changqing; Chen, Xinlei; Liu, Yun; Luo, Yu


    We provide further theoretical insights and experimental verification of the modal-dispersion-induced effective surface-plasmon polaritons (ESPPs) by engineering the transverse-electric (TE) modes in conventional rectangular waveguides. The complete field distributions, dispersion relations, and asymptotic frequency of the ESPPs are derived analytically. Wave-port excitations and smooth bridges are designed for the mode conversion between propagating modes in rectangular waveguides and the ESPPs. Analytical calculations and numerical simulations are performed for TE10 - and TE20 -mode-induced ESPPs, showing excellent agreement. Moreover, we design a double-layered substrate-integrated waveguide showing that ESPPs are supported at the interface between the two layers with different dielectric constants. This work opens up an avenue for low-frequency designer surface plasmons and may find potential applications in the design of compact filters, resonators, and sensors of ESPPs in the microwave and terahertz frequencies.

  11. Development of Traveling Wave Actuators Using Waveguides of Different Geometrical Forms

    Directory of Open Access Journals (Sweden)

    Ramutis Bansevicius


    Full Text Available The paper covers the research and development of piezoelectric traveling wave actuators using different types of the waveguides. The introduced piezoelectric actuators can be characterized by specific areas of application, different resolution, and torque. All presented actuators are ultrasonic resonant devices and they were developed to increase amplitudes of the traveling wave oscillations of the contact surface. Three different waveguides are introduced, that is, symmetrical, asymmetrical, and cone type waveguide. A piezoelectric ring with the sectioned electrodes is used to excite traveling wave oscillations for all actuators. Operating principle, electrode pattern, and excitation regimes of piezoelectric actuators are described. A numerical modelling of the actuators was performed to validate the operating principle and to calculate trajectories of the contact points motion. Prototype actuators were made and experimental study was performed. The results of numerical and experimental analysis are discussed.

  12. Photonic Crystal Waveguides in Terahertz Regime

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Huaiwu, E-mail: [State Key Laboratory of Electronic Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054 (China)


    Using the finite difference time domain method, the electromagnetic field distribution of THz waves in photonic crystals (PCs) T-splitters and Y-splitters had been simulated. The simulation results show that those different T-splitters and Y-splitters can divide the power in an input wave guide equally between two output waveguides. By the improved T-splitter with a rod in the junction, we achieved the 84% amplitude- frequency characteristics consistency of pass-band from 1.12 THz to 1.22 THz, and surpass the 76% consistency of common T-splitter. The improved Y-splitter with a rod in the junction and without rod in the corners has widest -3db bandwidth 0.224 THz, and the amplitude reaches 1655.727. The improved Y-splitter has better performance than other Y-splitters. Introducing the photonic band gap structure with L-type defect composed of three defects. Three high-Q resonant frequencies appeared simultaneously in some monitor coordinates. The wavelength-add-drop properties of L-type defects may be used in multi-carrier communication and multi-frequency-monitoring for the THz regime. Also, a carefully designed PCs can be used as high Q narrowband filter in THz band. These results provide a useful guide and a theoretical basis for the developments of THz functional components.

  13. WGM resonators for studying orbital angular momentum of a photon, and methods (United States)

    Matsko, Andrey B. (Inventor); Savchenkov, Anatoliy A. (Inventor); Maleki, Lute (Inventor); Strekalov, Dmitry V. (Inventor)


    An optical system, device, and method that are capable of generating high-order Bessel beams and determining the orbital angular momentum of at least one of the photons of a Bessel beam are provided. The optical system and device include a tapered waveguide having an outer surface defined by a diameter that varies along a longitudinal axis of the waveguide from a first end to an opposing second end. The optical system and device include a resonator that is arranged in optical communication with the first end of the tapered waveguide such that an evanescent field emitted from (i) the waveguide can be coupled with the resonator, or (ii) the resonator can be coupled with the waveguide.

  14. Nanoscale Plasmonic Devices Based on Metal-Dielectric-Metal Stub Resonators

    Directory of Open Access Journals (Sweden)

    Yin Huang


    Full Text Available We review some of the recent research activities on plasmonic devices based on metal-dielectric-metal (MDM stub resonators for manipulating light at the nanoscale. We first introduce slow-light subwavelength plasmonic waveguides based on plasmonic analogues of periodically loaded transmission lines and electromagnetically induced transparency. In both cases, the structures consist of a MDM waveguide side-coupled to periodic arrays of MDM stub resonators. We then introduce absorption switches consisting of a MDM plasmonic waveguide side-coupled to a MDM stub resonator filled with an active material.

  15. Experimental measurement of plasmonic nanostructures embedded in silicon waveguide gaps

    CERN Document Server

    Espinosa-Soria, Alba; Martínez, Alejandro


    In this work, we report numerical simulations and experiments of the optical response of a gold nanostrip embedded in a silicon strip waveguide gap at telecom wavelengths. We show that the spectral features observed in transmission and reflection when the metallic nanostructure is inserted in the gap are extremely different to those observed in free-space excitation. First, we find that interference between the guided field and the electric dipolar resonance of the metallic nanostructure results in high-contrast (> 10) spectral features showing an asymmetric Fano spectral profile. Secondly, we reveal a crossing in the transmission and reflection responses close to the nanostructure resonance wavelength as a key feature of our system. This approach, which can be realized using standard semiconductor nanofabrication tools, could lead to fully exploit the extreme properties of subwavelength metallic nanostructures in an on-chip configuration, with special relevance in fields such as biosensing or optical switchi...

  16. Using Multilayered Substrate Integrated Waveguide to Design Microwave Gain Equalizer

    Directory of Open Access Journals (Sweden)

    Yongfei Wang


    Full Text Available This paper presents the design and experiment of a novel microwave gain equalizer based on the substrate integrated waveguide (SIW technique. The proposed equalizer is formed by an SIW loaded by SIW resonators, which has very compact structure and can compensate for gain slope of microwave systems. Equivalent circuit analysis is given about the proposed structure for a better insight into the structure’s response. A Ku-Band equalizer with four SIW resonators is simulated and fabricated with a multilayer printed circuit board process. The measured results show good performance and agreement with the simulated results; an attenuation slope of −4.5 dB over 12.5–13.5 GHz is reached with a size reduction of 76%.

  17. Quantum Electrodynamics in Photonic Crystal Waveguides

    DEFF Research Database (Denmark)

    Nielsen, Henri Thyrrestrup

    in the local density of states (LDOS) in PhC waveguides. From decay rate measurements on quantum dot lines temperature tuned in the vicinity of the waveguide band edge, a β-factor for a single quantum dot of more then 85% has been extracted. Finite difference time domain simulations (FDTD) for disordered Ph...

  18. Topology optimization of two-dimensional waveguides

    DEFF Research Database (Denmark)

    Jensen, Jakob Søndergaard; Sigmund, Ole


    In this work we use the method of topology optimization to design two-dimensional waveguides with low transmission loss.......In this work we use the method of topology optimization to design two-dimensional waveguides with low transmission loss....

  19. Bends and splitters in graphene nanoribbon waveguides

    DEFF Research Database (Denmark)

    Zhu, Xiaolong; Yan, Wei; Mortensen, N. Asger


    We investigate the performance of bends and splitters in graphene nanoribbon waveguides. Although the graphene waveguides are lossy themselves, we show that bends and splitters do not induce any additional loss provided that the nanoribbon width is sub-wavelength. We use transmission line theory...

  20. Antenna arrays: waveguide layout designing automation


    Anamova, R. R.


    Waveguide layout designing automation in the large-sized phased antenna arrays is studied. A new methodology of the automation and algorithms based on the flexible connection routing method are suggested. Results are realized in the software module WDS (Waveguide Design Solution) based on SolidWorks system. This module gives an opportunity to decrease design and engineering time and costs.

  1. A hybrid semiconductor-glass waveguide laser

    NARCIS (Netherlands)

    Fan, Youwen; Oldenbeuving, Ruud; Klein, E.J.; Lee, Christopher James; Song, H.; Khan, M.R.H.; Offerhaus, Herman L.; van der Slot, Petrus J.M.; Boller, Klaus J.; Mackenzie, J.I.; Jelinkova, H.; Taira, T.; Ahmed, M.A.


    abstract .We report on a novel type of laser in which a semiconductor optical amplifier (SOA) receives frequency-selective feedback from a glass-waveguide circuit. The laser we present here is based on InP for operation in the 1.55 μm wavelength range. The Si3N4/SiO2 glass waveguide circuit

  2. A hybrid semiconductor-glass waveguide laser

    NARCIS (Netherlands)

    Fan, Y.; Oldenbeuving, R.M.; Klein, E.J.; Lee, C.J.; Song, H.; Khan, M.R.H.; Offerhaus, H.L.; Van der Slot, P.J.M.; Boller, K.J.


    We report on a novel type of laser in which a semiconductor optical amplifier (SOA) receives frequency-selective feedback from a glass-waveguide circuit. The laser we present here is based on InP for operation in the 1.55 µm wavelength range. The Si3N4/SiO2 glass waveguide circuit comprises two

  3. Silicon waveguides produced by wafer bonding

    DEFF Research Database (Denmark)

    Poulsen, Mette; Jensen, Flemming; Bunk, Oliver


    X-ray waveguides are successfully produced employing standard silicon technology of UV photolithography and wafer bonding. Contrary to theoretical expectations for similar systems even 100 mu m broad guides of less than 80 nm height do not collapse and can be used as one dimensional waveguides...

  4. Photonic crystal waveguides in artificial opals

    DEFF Research Database (Denmark)

    Lavrinenko, Andrei; Kiyan, Roman; Neumeister, Andrei


    3D photonic crystals based on Si inverted-opals are numerically explored as hosts for effective air-channel waveguides, which can serve as parts of photonic circuits. Two basic shapes of straight waveguides are considered: cylindrical and a chain of spheres. Modelling shows that transmission is h...

  5. Sapphire and other dielectric waveguide devices

    NARCIS (Netherlands)

    Pollnau, Markus


    Different fabrication methods have been explored successfully and surface and buried channel waveguide lasers have been demonstrated in Ti:sapphire for the first time. Since the propagation losses of these first-generation waveguides are still rather high, substantial improvement is required in

  6. Infrared nanoantenna couplers for plasmonic slot waveguide

    DEFF Research Database (Denmark)

    Andryieuski, Andrei; Malureanu, Radu; Lavrinenko, Andrei

    A slot plasmonic waveguide is promising solution as a replacement of electrical interconnects in the future optical integrated circuits. In this contribution we consider a set of compact solutions for coupling the infrared light from free space to the plasmonic slot waveguide. We systematically...

  7. Discontinuities during UV writing of waveguides

    DEFF Research Database (Denmark)

    Svalgaard, Mikael; Harpøth, Anders; Andersen, Marc


    UV writing of waveguides can be hampered by discontinuities where the index change process suddenly shuts down. We show that thermal effects may account for this behaviour.......UV writing of waveguides can be hampered by discontinuities where the index change process suddenly shuts down. We show that thermal effects may account for this behaviour....

  8. GaAs-based micro/nanomechanical resonators (United States)

    Yamaguchi, Hiroshi


    Micro/nanomechanical resonators have been extensively studied both for device applications, such as high-performance sensors and high-frequency devices, and for fundamental science, such as quantum physics in macroscopic objects. The advantages of GaAs-based semiconductor heterostructures include improved mechanical properties through strain engineering, highly controllable piezoelectric transduction, carrier-mediated optomechanical coupling, and hybridization with quantum low-dimensional structures. This article reviews our recent activities, as well as those of other groups, on the physics and applications of mechanical resonators fabricated using GaAs-based heterostructures.

  9. Designing and adjusting the thickness of polyvinylpyrrolidone waveguide layer on plasmonic nanofilm for humidity sensing (United States)

    Feng, Zhiqing; Bai, Lan; Guo, Lijiao; Cao, Baosheng; Wu, Jinlei; He, Yangyang


    We developed a fast response and high-resolution plasmonic waveguide sensor for sensing environmental humidity by converting the optical signal in the visible light region. The sensor was designed as a layer-on-layer film structure in which the hydrophilic polymer of polyvinylpyrrolidone (PVP) film served as the waveguide layer and was dip-coated onto the plasmonic gold (Au) nanofilm for sensing the environmental humidity. The amount of the absorbed water molecules on the PVP layer could affect the refractive index and thickness of the PVP, leading to a shift of the surface plasmon resonance peak position of Au nanofilm at the different order modes of the waveguide. The theoretic calculations indicated that the optimal thickness of the waveguide layer on the Au nanofilm ranged from 550 to 650 nm. By adjusting the thickness of the PVP layer to 560 nm, the high-resolution optical signals were observed in the visible light region with the humidity shifts ranging from 11% to 85% relative humidity (RH). Our work details a successful attempt to design and prepare the plasmonic waveguide sensor with the lost-cost polymer as the sensing layer for real-time detection of environmental humidity.

  10. Systematic Design of Slow Light Waveguides

    DEFF Research Database (Denmark)

    Wang, Fengwen

    Light can propagate much slower in photonic crystal waveguides and plasmonic waveguides than in vacuum. Slow light propagation in waveguides shows broad prospects in the terabit communication systems. However, it causes severe signal distortions and displays large propagation loss. Moreover......, an optimization formulation is presented to tailor the slope of the dispersion curve. The design robustness is enforced by considering different manufacturing realizations in the optimization procedure. Both free- and fixed-topology (circular-hole based) slow light photonic crystal waveguides are obtained using...... two different parameterizations. Detailed comparisons show that the bandwidth of slow light propagation can be significantly enhanced by allowing irregular geometries in the waveguides. To mitigate the propagation loss due to scattering in the photonic crystal waveg- uides, an optimization problem...

  11. Hybrid grapheme plasmonic waveguide modulators (United States)

    Ansell, D.; Thackray, B. D.; Aznakayeva, D. E.; Thomas, P.; Auton, G. H.; Marshall, O. P.; Rodriguez, F. J.; Radko, I. P.; Han, Z.; Bozhevolnyi, S. I.; Grigorenko, A. N.


    The unique optical and electronic properties of graphene allow one to realize active optical devices. While several types of graphene-based photonic modulators have already been demonstrated, the potential of combining the versatility of graphene with sub-wavelength field confinement of plasmonic/metallic structures is not fully realized. Here we report fabrication and study of hybrid graphene-plasmonic modulators. We consider several types of modulators and identify the most promising one for light modulation at telecom and near-infrared. Our proof-of-concept results pave the way towards on-chip realization of efficient graphene-based active plasmonic waveguide devices for optical communications.

  12. Photonic waveguides theory and applications

    CERN Document Server

    Boudrioua, Azzedine


    This book presents the principles of non-linear integrated optics. The first objective is to provide the reader with a thorough understanding of integrated optics so that they may be able to develop the theoretical and experimental tools to study and control the linear and non-linear optical properties of waveguides.The potential use of these structures can then be determined in order to realize integrated optical components for light modulation and generation. The theoretical models are accompanied by experimental tools and their setting in order to characterize the studied phenomenon. Th

  13. Theoretical investigation of Vernier effect based sensors with hybrid porous silicon-polymer optical waveguides (United States)

    Azuelos, Paul; Girault, Pauline; Lorrain, Nathalie; Poffo, Luiz; Hardy, Isabelle; Guendouz, Mohammed; Thual, Monique


    A new combination of porous silicon and polymer optical waveguides is investigated for two different designs of Vernier effect based sensors for the surface detection of Bovine Serum Albumin (BSA) molecules. The hybrid structures studied consist of two cascaded micro-resonators for one and a micro-resonator cascaded with a Mach-Zehnder for the other. Because of its high specific surface and bio-compatibility, we use porous silicon to implement the waveguides in the sensing part of the sensor into which BSA molecules are grafted. Polymer waveguides are then used for the reference part of the sensor because of their low optical losses. We consider the opto-geometric parameters of both waveguides for single mode propagation. Finally, optimized designs, taking into account standard experimental wavelength shift measurement limitation, are presented for both structures. We demonstrate a theoretical Limit Of Detection (LOD) of 0.019 pg mm-2 and a sensitivity of 12.5 nm/(pg mm-2) with these hybrid sensors. To our knowledge, these values are lower by a factor of 8 for the LOD and higher by a factor of 200 for the sensitivity, as compared to state of the art Vernier effect biosensors.

  14. Ultrafast Laser Fabrication of Bragg Waveguides in GLS Chalcogenide Glass

    Directory of Open Access Journals (Sweden)

    McMillen Ben


    Full Text Available We present work on the fabrication of Bragg waveguides in gallium-lanthanum-sulfide chalcogenide glass using an ultrafast laser. Waveguides were written with a single pass while modulating the writing beam. The spatial and temporal profile of the writing beam was ontrolled during waveguide fabrication in order to control the shape and size of the waveguide cross-section.

  15. Waveguiding Light into Silicon Oxycarbide

    Directory of Open Access Journals (Sweden)

    Faisal Ahmed Memon


    Full Text Available In this work, we demonstrate the fabrication of single mode optical waveguides in silicon oxycarbide (SiOC with a high refractive index n = 1.578 on silica (SiO2, exhibiting an index contrast of Δn = 8.2%. Silicon oxycarbide layers were deposited by reactive RF magnetron sputtering of a SiC target in a controlled process of argon and oxygen gases. The optical properties of SiOC film were measured with spectroscopic ellipsometry in the near-infrared range and the acquired refractive indices of the film exhibit anisotropy on the order of 10−2. The structure of the SiOC films is investigated with atomic force microscopy (AFM and scanning electron microscopy (SEM. The channel waveguides in SiOC are buried in SiO2 (n = 1.444 and defined with UV photolithography and reactive ion etching techniques. Propagation losses of about 4 dB/cm for both TE and TM polarizations at telecommunication wavelength 1550 nm are estimated with cut-back technique. Results indicate the potential of silicon oxycarbide for guided wave applications.

  16. Design and analysis of stepped impedance transformer from air filled waveguide to dielectric filled waveguide for high power microwave window applications (United States)

    Sindam, Bashaiah; Sharma, P. K.; Raju, K. C. James


    This paper describes a design to achieve good microwave power transmission from an air filled rectangular waveguide to a narrow dielectric filled waveguide using a stepped impedance transformer. A novel material Ba(Zn1/3Ta2/3)O3 (BZT) having high dielectric constant and low dielectric loss has been proposed as a microwave window. The advantages of using such dielectric resonator materials for these applications is that they make the size reduction of such microwave components possible without unleashing microwave dissipation. A high density (more than 97%) and good microwave dielectric properties are obtained for BZT samples through the solid state reaction method. The obtained dielectric parameters are used to calculate the dimensions of the narrow dielectric window section in waveguide geometry and the resulting dielectric window structure is simulated using the IMST Empire simulator. The maximum power transmission is obtained by the simulated structure with a dielectric filled waveguide window of thickness 7.4 mm at 3.7 GHz with bandwidth of 780 MHz, which corresponds to an insertion loss (S21) magnitude of 0.008 dB, and the return loss (S11) obtained at the same frequency is -43 dB. The microwave dielectric properties of the material used as well as the simulated results for the BZT based window are studied and compared with those of a conventional window.

  17. Compact pulley-type microring resonator with high quality factor (United States)

    Cai, Dong-Po; Lu, Jyun-Hong; Chen, Chii-Chang; Lee, Chien-Chieh; Lin, Chu-En; Yen, Ta-Jen


    A pulley-type microring resonator with ultra-small dimensions and ultra-high quality factor on a silicon-on-insulator wafer is fabricated and characterized. Simulation results show that the bending loss of the pulley-type microring resonator can be diminished by wrapping the curved waveguide around the microring, and that the energy loss from the output port can be decreased by tuning the width of the bus waveguide to achieve destructive interference. A quality factor of 1.73 × 105 is obtained in this experiment. The compact size of the pulley-type microring resonator with low bending loss is suitable for an integrated optical circuit.

  18. Heterostructures based on inorganic and organic van der Waals systems

    Directory of Open Access Journals (Sweden)

    Gwan-Hyoung Lee


    Full Text Available The two-dimensional limit of layered materials has recently been realized through the use of van der Waals (vdW heterostructures composed of weakly interacting layers. In this paper, we describe two different classes of vdW heterostructures: inorganic vdW heterostructures prepared by co-lamination and restacking; and organic-inorganic hetero-epitaxy created by physical vapor deposition of organic molecule crystals on an inorganic vdW substrate. Both types of heterostructures exhibit atomically clean vdW interfaces. Employing such vdW heterostructures, we have demonstrated various novel devices, including graphene/hexagonal boron nitride (hBN and MoS2 heterostructures for memory devices; graphene/MoS2/WSe2/graphene vertical p-n junctions for photovoltaic devices, and organic crystals on hBN with graphene electrodes for high-performance transistors.

  19. Analysis of Critical Dimensions for Nanowire Core-Multishell Heterostructures


    Yan, Xin; Fan, Shuyu; Zhang, Xia; Ren, Xiaomin


    Critical dimensions for nanowire core-multishell heterostructures are analyzed by using finite-element method based on the energy equilibrium criteria. Results show that the nanowire core-shell heterostructure can sufficiently reduce the strain in the shell and increase the critical shell thickness. The critical dimensions for the nanowire core-multishell heterostructure are determined by the stress fields generated at two heterointerfaces. For thin barrier, the critical dimensions decrease a...

  20. A review of nano-optics in metamaterial hybrid heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Mahi R. [Department of Physics and Astronomy, Western University, London N6G 3K7 (Canada)


    We present a review for the nonlinear nano-optics in quantum dots doped in a metamaterial heterostructure. The heterostructure is formed by depositing a metamaterial on a dielectric substrate and ensemble of noninteracting quantum dots are doped near the heterostructure interface. It is shown that there is enhancement of the second harmonic generation due to the surface plasmon polaritons field present at the interface.

  1. Bimodal wireless sensing with dual-channel wide bandgap heterostructure varactors (United States)

    Deen, David A.; Osinsky, Andrei; Miller, Ross


    A capacitive wireless sensing scheme is developed that utilizes an AlN/GaN-based dual-channel varactor. The dual-channel heterostructure affords two capacitance plateaus within the capacitance-voltage (CV) characteristic, owing to the two parallel two-dimensional electron gases (2DEGs) located at respective AlN/GaN interfaces. The capacitance plateaus are leveraged for the definition of two resonant states of the sensor when implemented in an inductively-coupled resonant LRC network for wireless readout. The physics-based CV model is compared with published experimental results, which serve as a basis for the sensor embodiment. The bimodal resonant sensor is befitting for a broad application space ranging from gas, electrostatic, and piezoelectric sensors to biological and chemical detection.

  2. Optical planar waveguide for cell counting (United States)

    LeBlanc, John; Mueller, Andrew J.; Prinz, Adrian; Butte, Manish J.


    Low cost counting of cells has medical applications in screening, military medicine, disaster medicine, and rural healthcare. In this report, we present a shallow, buried, planar waveguide fabricated by potassium ion exchange in glass that enables low-cost and rapid counting of metal-tagged objects that lie in the evanescent field of the waveguide. Laser light transmitted through the waveguide was attenuated proportionately to the presence of metal-coated microstructures fabricated from photoresist. This technology enables the low-cost enumeration of cells from blood, urine, or other biofluids.

  3. Suppression of crosstalk in coupled plasmonic waveguides

    CERN Document Server

    Kuznetsov, E V; Zyablovsky, A A; Vinogradov, A P; Lisyansky, A A


    We demonstrate the suppression of crosstalk between two dielectric nanowaveguides by placing an auxiliary linear waveguide between loaded waveguides spaced by one wavelength. The total cross-sectional dimension of the system containing two transmission lines is less than two microns that is hundred times smaller than a cross-section of a system made of dielectric fiber. The propagating modes in these waveguides are the sum and the difference of symmetric and antisymmetric modes of the coupled system. Crosstalk is suppressed by matching the wavenumbers of these modes. The analytically obtained results are confirmed by numerical simulation.

  4. Nanofocusing in a tapered graphene plasmonic waveguide

    DEFF Research Database (Denmark)

    Dai, Yunyun; Zhu, Xiaolong; Mortensen, N. Asger


    Gated or doped graphene can support plasmons making it a promising plasmonic material in the terahertz regime. Here, we show numerically that in a tapered graphene plasmonic waveguide mid- and far-infrared light can be focused in nanometer scales, far beyond the diffraction limit. The underlying...... physics lies in that when propagating along the direction towards the tip both the group and phase velocities of the plasmons supported by the tapered graphene waveguide are reduced accordingly, eventually leading to nanofocusing at the tip with a huge enhancement of optical fields. The nanofocusing...... of optical fields in tapered graphene plasmonic waveguides could be potentially exploited in the enhancement of light–matter interactions....

  5. Dispersion relations and bending losses of cylindrical and spherical shells, slabs, and slot waveguides. (United States)

    Kozyreff, Gregory; Acharyya, Nirmalendu


    We derive formulas for whispering gallery mode resonances and bending losses in infinite cylindrical dielectric shells and sets of concentric cylindrical shells. The formulas also apply to spherical shells and to sections of bent waveguides. The derivation is based on a Wentzel-Kramers-Brillouin (WKB) treatment of Helmholtz equation and can in principle be extended to any number of concentric shells. A distinctive limit analytically arises in the analysis when two shells are brought at very close distance to one another. In that limit, the two shells act as a slot waveguide. If the two shells are sufficiently apart, we identify a structural resonance between the individual shells, which can either lead to a substantial enhancement or suppression of radiation losses.

  6. Femtosecond laser writing of optical edge filters in fused silica optical waveguides. (United States)

    Grenier, Jason R; Fernandes, Luís A; Herman, Peter R


    The positional alignment of femtosecond laser written Bragg grating waveguides within standard and coreless optical fiber has been exploited to vary symmetry and open strong optical coupling to a high density of asymmetric cladding modes. This coupling was further intensified with tight focusing of the laser pulses through an oil-immersion lens to control mode size against an asymmetric refractive index profile. By extending this Bragg grating waveguide writing into bulk fused silica glass, strong coupling to a continuum of radiation-like modes facilitated a significant broadening to over hundreds of nanometers bandwidth that blended into the narrow Bragg resonance to form into a strongly isolating (43 dB) optical edge filter. This Bragg resonance defined exceptionally steep edge slopes of 136 dB/nm and 185 dB/nm for unpolarized and linearly polarized light, respectively, that were tunable through the 1450 nm to 1550 nm telecommunication band.

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

    National Research Council Canada - National Science Library

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


    We design a polarization-sensitive resonator for use in mid-infrared photodetectors, utilizing a photonic crystal cavity and a single or double-metal plasmonic waveguide to achieve enhanced detector...

  8. Few electron double quantum dots in InAs/InP nanowire heterostructures. (United States)

    Fuhrer, Andreas; Fröberg, Linus E; Pedersen, Jonas Nyvold; Larsson, Magnus W; Wacker, Andreas; Pistol, Mats-Erik; Samuelson, Lars


    We report on fabrication of double quantum dots in catalytically grown InAs/InP nanowire heterostructures. In the few-electron regime, starting with both dots empty, our low-temperature transport measurements reveal a clear shell structure for sequential charging of the larger of the two dots with up to 12 electrons. The resonant current through the double dot is found to depend on the orbital coupling between states of different radial symmetry. The charging energies are well described by a capacitance model if next-neighbor capacitances are taken into account.

  9. Simulation of internally referenced resonance in a three-layer-coated microsphere resonator (United States)

    Dong, Yongchao; Jin, Xueying; Wang, Keyi


    With the finite difference time domain (FDTD) method, whispering gallery modes (WGM) in a microsphere coated with three layers of high, low, and high refractive index (RI) are simulated. In the simulation, the coupling system includes a coating microsphere, a waveguide and a nanoscale gap separating the waveguide and the microsphere. A pulse with ultra-wide bandwidth that spans over several resonant modes of the resonator is used for simulation. Via waveguide coupling, the relative intensity spectra of the three layers and the transmission spectrum of the coupling system are obtained. We investigate the effects of the waveguide RI and the thickness of the low-RI layer on resonance characteristics. It is found that each of the two high-RI layers can sustain its own WGM if the values of RI and thickness of the three layers are appropriate. Furthermore, the effect of the RI of the surrounding medium on resonance characteristics is also studied. The simulation results show that a RI change of the surroundings will only change the resonance wavelength of the outer layer, and will not affect the WGM of the inner layer. Such property makes it feasible for a potential application in high-precision RI and temperature sensing.

  10. FDTD analysis of dielectric-loaded longitudinally slotted rectangular waveguides. (United States)

    Al-Rizzo, Hussain M; Younies, Hassan Z; Clark, Ken G; Tranquilla, Jim M


    A versatile electromagnetic (EM) computational algorithm, based on the Finite-Difference Time-Domain (FDTD) technique, is developed to analyze longitudinally oriented, square-ended, single slot fixtures and slot-pair configurations cut in the broad wall of a WR-975 guide operating at a frequency of 915 MHz. The finite conductivity of the waveguide walls is accounted for by employing a time-domain Surface-Impedance Boundary Conditions (SIBC) formulation. The proposed FDTD algorithm has been validated against measurements performed on a probe-excited slot cut along the center line of the broad wall of a WR-284 guide and available experimental data for energy coupled from a longitudinal slot pair in the broad wall of a WR-340 guide. Numerical results are-presented to exploit the influence of the constitutive parameters of the processed material as well as protective insulating window slabs mounted on the exterior surface of the slots. Particular attention is given to the resonant length, scattering parameters, and the electric field distribution within lossy objects placed in the near-field region over a range of slot offsets and workloads with extensive results being reported for the first time. It is shown that the FDTD technique can accurately predict the coupling and power absorption characteristics in loads located in the near field zone of the slotted waveguide structures and, therefore, should prove to be a powerful design tool applicable to a wide class of slotted waveguide applicators that may be difficult to analyze using other available techniques.

  11. Subwavelength-Sized Narrow-Band Anechoic Waveguide Terminations (United States)

    Santillán, Arturo; Ćrenlund, Emil; Bozhevolnyi, Sergey I.


    We propose and demonstrate the use of a pair of detuned acoustic resonators to efficiently absorb narrow-band sound waves in a terminated waveguide. The suggested configuration is relatively simple and advantageous for usage at low frequencies, since the dimensions of the resonators are very small compared to the wavelength. We present a theoretical description based on lumped parameters to calculate the absorption coefficient, which agrees very well with experimental data. The experimental results verify that the anechoic (reflection approximately -38 dB ) narrow-band (Δ f /f ˜0.1 ) termination with deeply subwavelength (<λ /10 ) sizes can be realized at a target frequency, suggesting thereby applications for noise control and sensing. As an illustration of possible applications for sound absorption in a room, we demonstrate by use of numerical simulations that a given axial resonant excitation in a room can be practically eliminated. Thus, a reduction of approximately 24 dB in the average acoustic energy is achieved in the room when using only four Helmholtz resonators. We also discuss various scenarios of noise control in rooms.

  12. RF MEMS Based Tunable Bowtie Shaped Substrate Integrated Waveguide Filter

    Directory of Open Access Journals (Sweden)

    M. Z. Ur Rehman


    Full Text Available A tunable bandpass filter based on a technique that utilizes substrate integrated waveguide (SIW and double coupling is presented. The SIW based bandpass filter is implemented using a bowtie shaped resonator structure. The bowtie shaped filter exhibits similar performance as found in rectangular and circular shaped SIW based bandpass filters. This concept reduces the circuit foot print of SIW; along with miniaturization high quality factor is maintained by the structure. The design methodology for single-pole triangular resonator structure is presented. Two different inter-resonator couplings of the resonators are incorporated in the design of the two-pole bowtie shaped SIW bandpass filter, and switching between the two couplings using a packaged RF MEMS switch delivers the tunable filter. A tunning of 1 GHz is achieved for two frequency states of 6.3 and 7.3 GHz. The total size of the circuit is 70mm x 36mm x 0.787 mm (LxWxH.

  13. Broadband amps sport coplanar waveguide (United States)

    Browne, Jack


    The design techniques, manufacturing methods and the performance envelope of VMA 110 bandwidth amplifiers are described. The devices are produced with a combination of coplanar waveguide, slotline and twinstrip media and result in gain ripples of 0.35 dB per 10 dB of gain. The ground plane is placed above the circuit board to allow access without drilling, thereby making the amplifiers suitable for use with surface-mount components, Si MMICs and GaAs MMICs. Well-controlled electromagnetic fields permit clustering functions with no fear of electrical interaction between different circuits. The devices are designed, optimized and artwork is formatted on a personal computer using CAD programs.

  14. Waveguides having patterned, flattened modes

    Energy Technology Data Exchange (ETDEWEB)

    Messerly, Michael J.; Pax, Paul H.; Dawson, Jay W.


    Field-flattening strands may be added to and arbitrarily positioned within a field-flattening shell to create a waveguide that supports a patterned, flattened mode. Patterning does not alter the effective index or flattened nature of the mode, but does alter the characteristics of other modes. Compared to a telecom fiber, a hexagonal pattern of strands allows for a three-fold increase in the flattened mode's area without reducing the separation between its effective index and that of its bend-coupled mode. Hexagonal strand and shell elements prove to be a reasonable approximation, and, thus, to be of practical benefit vis-a-vis fabrication, to those of circular cross section. Patterned flattened modes offer a new and valuable path to power scaling.

  15. Photon correlations in multimode waveguides

    Energy Technology Data Exchange (ETDEWEB)

    Poem, Eilon; Silberberg, Yaron [Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100 (Israel)


    We consider the propagation of classical and nonclassical light in multimode optical waveguides. We focus on the evolution of the few-photon correlation functions, which, much as the light-intensity distribution in such systems, evolve in a periodic manner, culminating in the ''revival'' of the initial correlation pattern at the end of each period. It is found that when the input state possesses nontrivial symmetries, the correlation revival period can be longer than that of the intensity, and thus the same intensity pattern can display different correlation patterns. We experimentally demonstrate this effect for classical, pseudothermal light, and compare the results with the predictions for nonclassical, quantum light.

  16. Thermal response in van der Waals heterostructures

    KAUST Repository

    Gandi, Appala


    We solve numerically the Boltzmann transport equations of the phonons and electrons to understand the thermoelectric response in heterostructures of M2CO2 (M: Ti, Zr, Hf) MXenes with transition metal dichalcogenide monolayers. Low frequency optical phonons are found to occur as a consequence of the van der Waals bonding, contribute significantly to the thermal transport, and compensate for the reduced contributions of the acoustic phonons (increased scattering cross-sections in heterostructures), such that the thermal conductivities turn out to be similar to those of the bare MXenes. Our results indicate that the important superlattice design approach of thermoelectrics (to reduce the thermal conductivity) may be effective for two-dimensional van der Waals materials when used in conjunction with intercalation. © 2016 IOP Publishing Ltd.

  17. Proximity coupling in superconductor-graphene heterostructures


    Lee, Gil-Ho; Lee, Hu-Jong


    This review discusses the electronic properties and the prospective research directions of superconductor-graphene heterostructures. The basic electronic properties of graphene are introduced to highlight the unique possibility of combining two seemingly unrelated physics, superconductivity and relativity. We then focus on graphene-based Josephson junctions, one of the most versatile superconducting quantum devices. The various theoretical methods that have been developed to describe graphene...

  18. Low-index discontinuity terahertz waveguides

    National Research Council Canada - National Science Library

    Michael Nagel; Astrid Marchewka; Heinrich Kurz


    ... of electric flux density at the dielectric interface. Attenuation, dispersion and single-mode confinement properties of two LID structures are discussed and compared with other THz waveguide solutions...

  19. Differential interference in a polymer waveguide

    National Research Council Canada - National Science Library

    Gut, K


    The paper presents the results of investigations concerning the measurement of the refractive index and the thickness of planar waveguide structures, obtained by photo polymerization of the polymer SU8...

  20. Holographic Waveguided See-Through Display Project (United States)

    National Aeronautics and Space Administration — To address the NASA need for lightweight, space suit-mounted displays, Luminit proposes a novel Holographic Waveguided See-Through Display. Our proposed Holographic...

  1. Fabrication of plasmonic waveguides for device applications

    DEFF Research Database (Denmark)

    Boltasseva, Alexandra; Leosson, Kristjan; Rosenzveig, Tiberiu


    We report on experimental realization of different metal-insulator geometries that are used as plasmonic waveguides guiding electromagnetic radiation along metal-dielectric interfaces via excitation of surface plasmon polaritons (SPPs). Three configurations are considered: metal strips, symmetric...

  2. Optical waveguides in hard crystalline materials

    NARCIS (Netherlands)

    Pollnau, Markus


    The recent results of our research group and collaborators in the field of fabrication, characterization, and applications of optical waveguides in hard crystalline materials, specifically in sapphire and Ti:sapphire, are reviewed.

  3. Laser written waveguide photonic quantum circuits

    National Research Council Canada - National Science Library

    Graham D. Marshall; Alberto Politi; Jonathan C. F. Matthews; Peter Dekker; Martin Ams; Michael J. Withford; Jeremy L. O'Brien


    We report photonic quantum circuits created using an ultrafast laser processing technique that is rapid, requires no lithographic mask and can be used to create three-dimensional networks of waveguide devices...

  4. Quantum random walks circuits with photonic waveguides

    NARCIS (Netherlands)

    Peruzzo, Alberto; Matthews, Jonathan; Politi, Alberto; Lobino, Mirko; Zhou, Xiao-Qi; Thompson, Mark G.; O'Brien, Jeremy; Matsuda, Nobuyuki; Ismail, N.; Worhoff, Kerstin; Bromberg, Yaron; Lahini, Yoav; Silberberg, Yaron


    Arrays of 21 evanescently coupled waveguides are fabricated to implement quantum random walks and a generalised form of two-photon non-classical interference, which observed via two photon correlation.

  5. High index contrast UV-written waveguides

    DEFF Research Database (Denmark)

    Svalgaard, Mikael; Færch, Kjartan Ullitz

    By increasing the concentration of molecular hydrogen in germanosilica samples, we show that buried channel waveguides with an index step of up to 0.02 can be fabricated using the directUV writing technique....

  6. Direct UV-writing of waveguides

    DEFF Research Database (Denmark)

    Færch, Kjartan Ullitz


    The research presented in this phd thesis is concerned about fabrication of waveguide structures in photosensitized germanosilica thin films by exposure to Ultra-violet (UV) radiation. Using a high pressure loading system and a waveguide fabrication setup, planar waveguiding structures with an UV...... induced refractive index change of more than 10-2 have been obtained. New insight, with respect to understanding the UV induced index change obtained by direct UV writing, has been provided, through experiments conducted with such high-pressure loaded germanosilica samples. This include measurements...... of the UV induced refractive index change, and spectroscopic measurements of the defect distribution, for various fabrication parameters. A method to measure the concentration of molecular hydrogen in thin film planar waveguide samples is established and validated for hydrogen loadign at up to 12 mole...

  7. Strain engineering of van der Waals heterostructures. (United States)

    Vermeulen, Paul A; Mulder, Jefta; Momand, Jamo; Kooi, Bart J


    Modifying the strain state of solids allows control over a plethora of functional properties. The weak interlayer bonding in van der Waals (vdWaals) materials such as graphene, hBN, MoS2, and Bi2Te3 might seem to exclude strain engineering, since strain would immediately relax at the vdWaals interfaces. Here we present direct observations of the contrary by showing growth of vdWaals heterostructures with persistent in-plane strains up to 5% and we show that strain relaxation follows a not yet reported process distinctly different from strain relaxation in three-dimensionally bonded (3D) materials. For this, 2D bonded Bi2Te3-Sb2Te3 and 2D/3D bonded Bi2Te3-GeTe multilayered films are grown using Pulsed Laser Deposition (PLD) and their structure is monitored in situ using Reflective High Energy Electron Diffraction (RHEED) and post situ analysis is performed using Transmission Electron Microscopy (TEM). Strain relaxation is modeled and found to solely depend on the layer being grown and its initial strain. This insight demonstrates that strain engineering of 2D bonded heterostructures obeys different rules than hold for epitaxial 3D materials and opens the door to precise tuning of the strain state of the individual layers to optimize functional performance of vdWaals heterostructures.

  8. Application of exterior calculus to waveguides


    Ferraro, Rafael


    Exterior calculus is a powerful tool to search for solutions to the electromagnetic field equations, whose strength can be better appreciated when applied to work out non-trivial configurations. Here we show how to exploit this machinery to obtain the electromagnetic TM and TE modes in hollow cylindrical waveguides. The proper use of exterior calculus and Lorentz boosts will straightforwardly lead to such solutions and the respective power transmitted along the waveguide.

  9. Thermotherapeutic waveguide applicator for cancer treatment (United States)

    Cvek, Jakub; Vrba, Jan


    Thermotherapy is one of the standard methods of the complex cancer treatment. In many studies, the improvement in local tumor control and free life survival has been shown. Goal of this project was realization of Evanescent Mode Waveguide applicator and its comparison with Waveguide Applicator, which is clinically used. The optimization of the Evanescent Mode Applicator has been studied with aid of numerical methods (FDTD).

  10. Accurate modelling of UV written waveguide components

    DEFF Research Database (Denmark)

    Svalgaard, Mikael

    BPM simulation results of UV written waveguide components that are indistinguishable from measurements can be achieved on the basis of trajectory scan data and an equivalent step index profile that is very easy to measure.......BPM simulation results of UV written waveguide components that are indistinguishable from measurements can be achieved on the basis of trajectory scan data and an equivalent step index profile that is very easy to measure....

  11. Accurate modeling of UV written waveguide components

    DEFF Research Database (Denmark)

    Svalgaard, Mikael

    BPM simulation results of UV written waveguide components that are indistinguishable from measurements can be achieved on the basis of trajectory scan data and an equivalent step index profile that is very easy to measure.......BPM simulation results of UV written waveguide components that are indistinguishable from measurements can be achieved on the basis of trajectory scan data and an equivalent step index profile that is very easy to measure....

  12. 70-nm-bandwidth achromatic waveguide coupler. (United States)

    Mendes, S B; Li, L; Burke, J J; Lee, J E; Saavedra, S S


    We report a general approach to the design of broadband waveguide couplers. A double-parallel grating assembly is used to cancel the first chromatic order, and a proper choice of prism glass and base angle is made to compensate for the second chromatic order. The technique was applied to a Corning glass 7059 waveguide, and a spectral bandwidth of 70 nm was measured by the use of two complementary procedures.

  13. Optical waveguide device with an adiabatically-varying width

    Energy Technology Data Exchange (ETDEWEB)

    Watts,; Michael R. (Albuquerque, NM), Nielson; Gregory, N [Albuquerque, NM


    Optical waveguide devices are disclosed which utilize an optical waveguide having a waveguide bend therein with a width that varies adiabatically between a minimum value and a maximum value of the width. One or more connecting members can be attached to the waveguide bend near the maximum value of the width thereof to support the waveguide bend or to supply electrical power to an impurity-doped region located within the waveguide bend near the maximum value of the width. The impurity-doped region can form an electrical heater or a semiconductor junction which can be activated with a voltage to provide a variable optical path length in the optical waveguide. The optical waveguide devices can be used to form a tunable interferometer (e.g. a Mach-Zehnder interferometer) which can be used for optical modulation or switching. The optical waveguide devices can also be used to form an optical delay line.

  14. Design of mode converters from TE circular om modes in circular waveguides to TE rectangular mo modes in rectangular waveguides for high power applications in the frequency range 1 to 30 GHz (United States)

    Janzen, G.


    A mode converter for transitions from circular symmetric modes to rectangular waveguide modes and vice versa for high power applications in plasma heating experiments is described. The converter conserves the power of all circular symmetric modes emitted by a gyrotron and aligns the fields into linearly polarized modes required for effective plasma heating by electron cyclotron or by lower hybrid resonance absorption. It also allows a convenient combination of the power output of several klystrons and mode conversion into modes with low attenuation. Suitable combinations of waveguide diameter and number of sectors dividing (or combining) the power avoid the excitation of unwanted modes.

  15. Printed circuit board permittivity measurement using waveguide and resonator rings

    NARCIS (Netherlands)

    Op 't Land, Sjoerd; Tereshchenko, O.V.; Ramdani, Mohamed; Leferink, Frank Bernardus Johannes; Perdriau, Richard


    Knowing the frequency dependent complex permittivity of Printed Circuit Board (PCB) substrates is important in modern electronics. In this paper, two methods for measuring the permittivity are applied to the same Flame Resistant (FR4) substrate and the results are compared. The reference measurement

  16. Hybrid multimode resonators based on grating-assisted counter-directional couplers. (United States)

    Davis, Jordan A; Grieco, Andrew; Souza, Mario C M M; Frateschi, Newton C; Fainman, Yeshaiahu


    Research thrusts in silicon photonics are developing control operations using higher order waveguide modes for next generation high-bandwidth communication systems. In this context, devices allowing optical processing of multiple waveguide modes can reduce architecture complexity and enable flexible on-chip networks. We propose and demonstrate a hybrid resonator dually resonant at the 1st and 2nd order modes of a silicon waveguide. We observe 8 dB extinction ratio and modal conversion range of 20 nm for the 1st order quasi-TE mode input.

  17. Tunable slow-light multi-mode photonic crystal waveguides based on the coupling of square cavities (United States)

    Feng, Shuai; Yang, GuoJian; Li, YuXi; Chen, Xiao; Wang, YiQuan; Wang, WenZhong


    The light transmission properties through two-dimensional photonic crystal waveguides based on coupling of square cavities are studied by the finite-difference time-domain technique. Through interlacing the adjacent cavities along the direction vertical to the waveguide, the coupling distance between the adjacent cavities is extended, and the group velocity of the guiding modes can be slowed by five-fold compared with that in vacuum. Because of the different spatial field distributions of various resonant modes, the corresponding group velocities are also different for the same CROW structure.

  18. The design of a simulated in-line side-coupled 6 MV linear accelerator waveguide. (United States)

    St Aubin, Joel; Steciw, Stephen; Fallone, B G


    The design of a 3D in-line side-coupled 6 MV linac waveguide for medical use is given, and the effect of the side-coupling and port irises on the radio frequency (RF), beam dynamics, and dosimetric solutions is examined. This work was motivated by our research on a linac-MR hybrid system, where accurate electron trajectory information for a clinical medical waveguide in the presence of an external magnetic field was needed. For this work, the design of the linac waveguide was generated using the finite element method. The design outlined here incorporates the necessary geometric changes needed to incorporate a full-end accelerating cavity with a single-coupling iris, a waveguide-cavity coupling port iris that allows power transfer into the waveguide from the magnetron, as well as a method to control the RF field magnitude within the first half accelerating cavity into which the electrons from the gun are injected. With the full waveguide designed to resonate at 2998.5 +/- 0.1 MHz, a full 3D RF field solution was obtained. The accuracy of the 3D RF field solution was estimated through a comparison of important linac parameters (Q factor, shunt impedance, transit time factor, and resonant frequency) calculated for one accelerating cavity with the benchmarked program SUPERFISH. It was found that the maximum difference between the 3D solution and SUPERFISH was less than 0.03%. The eigenvalue solver, which determines the resonant frequencies of the 3D side-coupled waveguide simulation, was shown to be highly accurate through a comparison with lumped circuit theory. Two different waveguide geometries were examined, one incorporating a 0.5 mm first side cavity shift and another with a 1.5 mm first side cavity shift. The asymmetrically placed side-coupling irises and the port iris for both models were shown to introduce asymmetries in the RF field large enough to cause a peak shift and skewing (center of gravity minus peak shift) of an initially cylindrically uniform

  19. Diffraction of a Waveguide Mode in a Nanowire

    DEFF Research Database (Denmark)

    Bordo, Vladimir


    can be calculated numerically, such an approach does not allow comprehensive analysis of the problem. In the present talk, the rigorous theory of reflection and diffraction of a waveguide mode at the end of a semi-infinite dielectric circular cylinder is developed. The theory assumes an arbitrary...... ratio between the cylinder radius and the wavelength and hence it can be used for the description of the nanowire optical properties. An exact solution of this problem is found by the use of fictitious electric and magnetic current sheets located at the end of the cylinder. The solution has the form....... It is shown that the polarization of the electromagnetic field is not changed upon reflection and its amplitude is zero in the far-field limit. The extension of this approach to the case of a nanowire of a finite length is also discussed. The normal modes of such a resonator which are analogs of the Fabry...

  20. A Waveguide Platform for Collective Light-Atom Interaction

    DEFF Research Database (Denmark)

    Sørensen, Heidi Lundgaard

    In this work a tapered optical fiber is studied as a waveguide platform for efficient collective light-atom interaction. We present an allcomputer controlled heat-and-pull setup with which a standard optical fiber can reproducible be tapered down to sub-micron waist size. The resulting fiber shape...... is compared against a prediction derived from a numerical model build upon an easy experimental calibration of the viscosity profile within the heater. Very good agreement between the modeled and measured fiber shape is found. We next study the coherent back-scattering off atoms confined as two one......-dimensional strings in the evanescent field of a tapered optical fiber. By applying a near-resonant standing wave field, the atoms are arranged into a periodic Bragg structure in close analogy to a photo-refractive medium with a refractive index grating. We observe more than 10% power reflection off about 1000...

  1. Mid-infrared refractive index sensing using optimized slotted photonic crystal waveguides (United States)

    Kassa-Baghdouche, Lazhar; Cassan, Eric


    Slotted photonic crystal waveguides (SPCWs) were designed to act as refractive index sensing devices at mid-infrared (IR) wavelengths around λ = 3.6 μm. In particular, effort was made to engineer the input and output slot waveguide interfaces in order to increase the effective sensitivity through resonant tapering. A slotted PhC waveguide immersed in air and liquid cladding layers was considered. To determine the performance of the sensor, the sensitivity of the device was estimated by calculating the shift in the upper band edge of the output transmission spectrum. The results showed that the sensitivity of a conventionally designed SPCW followed by modifications in the structure parameter yielded a 510 nm shift in the wavelength position of the upper band edge, indicating a sensitivity of more than 1150 nm per refractive index unit (RIU) with an insertion loss level of -0.3 dB. This work demonstrates the viability of photonic crystal waveguide high sensitivity devices in the Mid-IR, following a transposition of the concepts inherited from the telecom band and an optimization of the design, in particular a minimization of photonic device insertion losses.

  2. Progress in joining, reuse, and customization of WR284 waveguide in the laboratory (United States)

    Clark, Mike; Flanagan, Ken; Milhone, Jason; Nonn, Paul; Forest, Cary


    A system of five 20 kW magnetrons is being installed for the Big Red Ball (BRB) to produce and heat the plasma with 2.45GHz RF energy. An existing system of two 6 kW magentrons of the same frequency is actively used for the same purpose on Plasma Couette Experiment Upgrade (PCX-U). In each experiment, the RF is transmitted to the vessel via WR284 waveguide. Waveguide occasionally needs to be disassembled, modified and rebuilt for different reasons such as physics interests, ongoing problems (arcing), or efficient utilization of laboratory space. Reuse of disassembled waveguide parts is desirable for cost savings. Methods of assembly, disassembly, and modification of waveguide will be discussed. Also, frequently used designs of chokes, windows, and limiters will be shown. Materials used include copper, brass, and even aluminum. The vacuum vessel of PCX-U is a 1 meter diameter, 1 meter tall cylinder comprised of ¼'' thick stainless steel. PCX-U has one removable end. The vacuum vessel of the BRB is a 3 meter diameter, sphere comprised of two hemispheres of 1-¼'' thick cast A356 aluminum. Rings comprised of hundreds of SmCo magnets in each vessel create a cusp field to contain the plasma and provide a resonance surface for the RF. Supported by NSF and DoE.

  3. Integration of atomic layer deposited nanolaminates on silicon waveguides (Conference Presentation) (United States)

    Autere, Anton; Karvonen, Lasse; Säynätjoki, Antti; Roussey, Matthieu; Roenn, John; Färm, Elina; Kemell, Marianna; Tu, Xiaoguang; Liow, Tsung-Yang; Lo, Patrick; Ritala, Mikko; Leskelä, Markku; Lipsanen, Harri; Honkanen, Seppo; Sun, Zhipei


    Despite all the eminent advantages of silicon photonics, other materials need to be integrated to fulfill the functions that are difficult to realize with silicon alone. This is because silicon has a low light emission efficiency and a low electro-optic coefficient, limiting the use of silicon as a material for light sources and modulators. A strong two-photon absorption (TPA) at high intensities also limits the use of silicon in applications exploiting nonlinear effects. In addition, signal amplification is needed to compensate the insertion and propagation losses in silicon nanowaveguides. To address these issues we have demonstrated the integration of atomic layer deposited nanolaminates on silicon waveguides. Firstly we demonstrate slot waveguide ring resonators patterned on a silicon-on-insulator (SOI) wafer coated with an atomic layer deposited organic/inorganic nanolaminate structure, which consists of alternating layers of tantalum pentoxide (Ta2O5) and polyimide (PI) [1]. These materials were selected since the ALD process for depositing Ta2O5/PI nanolaminate films is already available [2] and both materials exhibit high third order nonlinearities [3-4]. In our nanolaminate ring resonators, the optical power is not only confined in the narrow central air slot but also in several parallel sub-10 nm wide vertical polyimide slots. This indicates that the mode profiles in the silicon slot waveguide can be accurately tuned by the atomic layer deposition (ALD) method. Our results show that ALD of organic and inorganic materials can be combined with conventional silicon waveguide fabrication techniques to create slot waveguide ring resonators with varying mode profiles. Secondly we demonstrate the integration of atomic layer deposited erbium-doped aluminum oxide (Al2O3) nanolaminates on silicon waveguides. This method provides an efficient way for controlling the concentration and distribution of erbium ions. We have applied this method on silicon strip and slot

  4. Dynamic nonlinear thermal optical effects in coupled ring resonators

    Directory of Open Access Journals (Sweden)

    Chenguang Huang


    Full Text Available 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.

  5. Gbps terahertz external modulator based on a composite metamaterial with a double-channel heterostructure. (United States)

    Zhang, Yaxin; Qiao, Shen; Liang, Shixiong; Wu, Zhenhua; Yang, Ziqiang; Feng, Zhihong; Sun, Han; Zhou, Yucong; Sun, Linlin; Chen, Zhi; Zou, Xianbing; Zhang, Bo; Hu, Jianhao; Li, Shaoqian; Chen, Qin; Li, Ling; Xu, Gaiqi; Zhao, Yuncheng; Liu, Shenggang


    The past few decades have witnessed a substantial increase in terahertz (THz) research. Utilizing THz waves to transmit communication and imaging data has created a high demand for phase and amplitude modulation. However, current active THz devices, including modulators and switches, still cannot meet THz system demands. Double-channel heterostructures, an alternative semiconductor system, can support nanoscale two-dimensional electron gases (2DEGs) with high carrier concentration and mobility and provide a new way to develop active THz devices. In this Letter, we present a composite metamaterial structure that combines an equivalent collective dipolar array with a double-channel heterostructure to obtain an effective, ultrafast, and all-electronic grid-controlled THz modulator. Electrical control allows for resonant mode conversion between two different dipolar resonances in the active device, which significantly improves the modulation speed and depth. This THz modulator is the first to achieve a 1 GHz modulation speed and 85% modulation depth during real-time dynamic tests. Moreover, a 1.19 rad phase shift was realized. A wireless free-space-modulation THz communication system based on this external THz modulator was tested using 0.2 Gbps eye patterns. Therefore, this active composite metamaterial modulator provides a basis for the development of effective and ultrafast dynamic devices for THz wireless communication and imaging systems.

  6. Plasmon induced absorption in a graphene-based nanoribbon waveguide system and its applications in logic gate and sensor (United States)

    Zhang, Tian; Zhou, Jinzan; Dai, Jian; Dai, Yitang; Han, Xu; Li, Jianqiang; Yin, Feifei; Zhou, Yue; Xu, Kun


    In this article, nanoscale integrated logic gates and a refractive index sensor both based on the tunable plasmon induced absorption (PIA) effect are proposed and investigated by employing a plasmonic waveguide nanostructure. Except for the direct and indirect coupling mechanism which is employed to explain the single PIA effect, the transmission of a three-resonators-coupled waveguide system is deduced theoretically to explain the dual PIA effects. Our calculated results prove that high tunability in wavelength and amplitude of the PIA effect can be achieved by tuning the Fermi levels of the graphene nanoribbons. By taking advantage of the interferometric effect, the logic gates are realized in this ultracompact structure based on the PIA effect in the mid-infrared region. The numerical results reveal that, for the plasmonic logic gate with coupling length of 60 nm, a high extinction ratio (>23.5 dB) can be achieved within a footprint of  graphene-based waveguide system.

  7. Finite Ground Coplanar (FGC) Waveguide: It's Characteristics and Advantages for Use in RF and Wireless Communication Circuits (United States)

    Ponchak, George E.; Katehi, Linda P. B.; Tentzeris, Emmanouil M.


    To solve many of the problems encountered when using conventional coplanar waveguide (CPW) with its semi-infinite ground planes, a new version of coplanar waveguide with electrically narrow ground planes has been developed. This new transmission line which we call Finite Ground Coplanar (FGC) waveguide has several advantages which make it a better transmission line for RF and wireless circuits. Since the ground planes are electrically narrow, spurious resonances created by the CPW ground planes and the metal carrier or package base are eliminated. In addition, lumped and distributed circuit elements may now be integrated into the ground strips in the same way as they traditionally have been integrated into the center conductor to realize novel circuit layouts that are smaller and have less parasitic reactance. Lastly, FGC is shown to have lower coupling between adjacent transmission lines than conventional CPW.

  8. Collective dark states controlled transmission in plasmonic slot waveguide with a stub coupled to a cavity dimer

    CERN Document Server

    Liu, Zhenzhen; Zhang, Qiang; Zhang, Xiaoming; Tao, Keyu


    We report collective dark states controlled transmission in metal-dielectric-metal waveguides with a stub coupled to two twin cavities, namely, plasmonic waveguide-stub-dimer systems. In absence of one individual cavity in the dimer, plasmon induced transparency (PIT) is possible when the cavity and the stub have the same resonance frequency. However, it is shown that the hybridized modes in the dimer collectively generate two dark states which make the stub-dimer "invisible" to the straight waveguide, splitting the original PIT peak into two in the transmission spectrum. Simultaneously, the original PIT peak becomes a dip due to dark state interaction, yielding anti-PIT-like modulation of the transmission. With full-wave electromagnetic simulation, we demonstrate that this transition is controlled by the dimer-stub separation and the dimer-stub relative position. All results are analytically described by the temporal coupled mode theory. Our results may be useful in designing densely integrated optical circu...

  9. Adaptive coupling approach for single mode VCSELs with polymer waveguides

    NARCIS (Netherlands)

    Bosman, E.; Elmogi, A.; Wiegersma, S.; Berg, H. van den; Ortsiefer, M.; Daly, A.; Duis, J.; Steenberge, G. van


    A novel coupling approach for single mode VCSELs and planar optical waveguides is presented. The coupling is based on the embedding of the VCSELs inside the substrate and the adaptive fabrication of waveguides on top.

  10. Under-Coupling Whispering Gallery Mode Resonator Applied to Resonant Micro-Optic Gyroscope. (United States)

    Qian, Kun; Tang, Jun; Guo, Hao; Liu, Wenyao; Liu, Jun; Xue, Chenyang; Zheng, Yongqiu; Zhang, Chengfei


    As an important sensing element, the whispering gallery mode resonator (WGMR) parameters seriously affect the resonant micro-optic gyroscope (RMOG) performance. This work proposes an under-coupling resonator to improve the resonator's Q value and to optimize the coupling coefficient to maximize the RMOG's sensitivity. GeO₂-doped silica waveguide-type resonators with different coupling coefficients were simulated, designed, fabricated and tested. An under-coupling ring resonator with a quality factor of 10 million is reported. The RMOG system was built based on this resonator and the scale factor was tested on a uniaxial high-precision rotating platform. Experimental results show that this resonator could improve the RMOG sensitivity by five times.

  11. Room-temperature giant magneto-mechanical-electric cross-coupling in Si-integrated PbZr0.52Ti0.48O3/Ni50Mn35In15 multiferroic heterostructures (United States)

    Singh, Kirandeep; Kaur, Davinder


    The current study reports the strong magnetoelectric coupling (M-E) in silicon (Si)-integrated ferromagnetic shape memory alloy-based PZT/Ni-Mn-In thin-film multiferroic heterostructure. The strain-mediated nature of converse M-E coupling is reflected from the butterfly-shaped normalized magnetization (M/M s) versus electric field plots. The direct M-E properties of the heterostructure were measured with a frequency of AC magnetic field, bias magnetic field, as well as with temperature. A maximum direct M-E coupling in the bilayered thin-film multiferroic heterostructures occurred at resonance frequencies around the first-order structural transitional temperature of the bottom Ni-Mn-In layer. It was observed that the measuring temperature remarkably affects the direct M-E characteristic of the heterostructure. A large direct ME effect and converse ME effect coefficient α DME  ~  894 mV cm-1.Oe and α CME ~ 2.7  ×  10-5 s m-1, respectively, were achieved in the bilayer at room temperature. The mechanism of direct as well as converse M-E effects in the thin-film multiferroic heterostructures is discussed. The electrically driven angular dependence of normalized magnetization (M/M s) reveals the twofold symmetric magnetic anisotropy of the heterostructure, with the drastic shifting of the magnetic hard axis at E  >  E c (coercivity of PZT).

  12. Electron transport in InAs nanowires and heterostructure nanowire devices (United States)

    Thelander, C.; Björk, M. T.; Larsson, M. W.; Hansen, A. E.; Wallenberg, L. R.; Samuelson, L.


    Nanowires in the InAs/InP material system are grown with catalyst-assisted chemical beam epitaxy. Ohmic contacts are then fabricated to selected wires, allowing electron transport measurements to be carried out at room-temperature as well as at low T. InAs nanowires show strong quantum confinement effects, where thin wires (Heterostructure barriers of InP are also incorporated into InAs wires to produce resonant tunneling diodes and single-electron transistors (SETs) with different dot lengths. Wires containing dots with a length of 100 nm function as ideal SETs, whereas the transport in wires with 15 nm long dots is strongly governed by quantum confinement and resonant tunneling. For the smaller dots it is possible to observe electron transport through excited states.

  13. Piezostrain tuning exchange bias mediated by electric field in composite heterostructure (United States)

    Li, Pingping; Zhou, Cai; Wang, Wenqiang; Cao, Cuimei; Yao, Jinli; Jiang, Changjun


    The change of unidirectional anisotropy and uniaxial anisotropy field turned by piezostrain in an IrMn/Co/Ta/Pb(Mg1/3Nb2/3)O3–PbTiO3 heterostructure with an exchange bias was investigated by ferromagnetic resonance at room temperature. The curve of the magnetic resonance field versus the electric fields showed an asymmetric butterfly-like behavior, which was consistent with the result of strain versus electric field curves. This butterfly-like behavior can be attributed to the piezostrain effect. Specifically, the non-volatile uniaxial anisotropy field and unidirectional anisotropy field behavior under different electric fields induced by piezostrain effect were obtained. Our result is crucial for further application of future multiferroic devices.

  14. Trilayer TMDC Heterostructures for MOSFETs and Nanobiosensors (United States)

    Datta, Kanak; Shadman, Abir; Rahman, Ehsanur; Khosru, Quazi D. M.


    Two dimensional materials such as transition metal dichalcogenides (TMDC) and their bi-layer/tri-layer heterostructures have become the focus of intense research and investigation in recent years due to their promising applications in electronics and optoelectronics. In this work, we have explored device level performance of trilayer TMDC heterostructure (MoS2/MX2/MoS2; M = Mo or, W and X = S or, Se) metal oxide semiconductor field effect transistors (MOSFETs) in the quantum ballistic regime. Our simulation shows that device `on' current can be improved by inserting a WS2 monolayer between two MoS2 monolayers. Application of biaxial tensile strain reveals a reduction in drain current which can be attributed to the lowering of carrier effective mass with increased tensile strain. In addition, it is found that gate underlap geometry improves electrostatic device performance by improving sub-threshold swing. However, increase in channel resistance reduces drain current. Besides exploring the prospect of these materials in device performance, novel trilayer TMDC heterostructure double gate field effect transistors (FETs) are proposed for sensing Nano biomolecules as well as for pH sensing. Bottom gate operation ensures these FETs operating beyond Nernst limit of 59 mV/pH. Simulation results found in this work reveal that scaling of bottom gate oxide results in better sensitivity while top oxide scaling exhibits an opposite trend. It is also found that, for identical operating conditions, proposed TMDC FET pH sensors show super-Nernst sensitivity indicating these materials as potential candidates in implementing such sensor. Besides pH sensing, all these materials show high sensitivity in the sub-threshold region as a channel material in nanobiosensor while MoS2/WS2/MoS2 FET shows the least sensitivity among them.

  15. On the use of slow light for enhancing waveguide properties

    DEFF Research Database (Denmark)

    Mørk, Jesper; Nielsen, Torben Roland


    On the basis of a general analysis of waveguides containing a dispersive material, we identify conditions under which slow-light propagation may enhance the gain, absorption, or phase change. The enhancement is shown to depend on the slow-light mechanism and the translational symmetry...... of the waveguide. A combination of material and waveguide dispersion may strongly enhance the control of light speed, e.g., using electromagnetically induced transparency in quantum dots embedded in a photonic crystal waveguide....

  16. Optical micromanipulation of freestanding microstructures with embedded waveguides

    DEFF Research Database (Denmark)

    Palima, Darwin; Bañas, Andrew Rafael; Vizsnyiczai, Gaszton


    Optically micromanipulated waveguides can be arbitrarily positioned and oriented for targeted light delivery. At the same time, controlled light deflection in designed waveguides can be exploited to exert optical forces for new optical micromanipulation modalities.......Optically micromanipulated waveguides can be arbitrarily positioned and oriented for targeted light delivery. At the same time, controlled light deflection in designed waveguides can be exploited to exert optical forces for new optical micromanipulation modalities....

  17. Antimonide Heterostructure Nanowires - Growth, Physics and Devices


    Borg, Mattias


    This thesis investigates the growth and application of antimonide heterostructure nanowires for low-power electronics. In the first part of the thesis, GaSb, InSb and InAsSb nanowire growth is presented, and the distinguishing features of the growth are described. It is found that the presence of Sb results in more than 50 at. % group-III concentration in the Au seed particle on top of the nanowires. It is further concluded that the effective V/III ratio inside the seed particle is reduced co...

  18. Exciton broadening in WS2/graphene heterostructures (United States)

    Hill, Heather M.; Rigosi, Albert F.; Raja, Archana; Chernikov, Alexey; Roquelet, Cyrielle; Heinz, Tony F.


    We have used optical spectroscopy to observe spectral broadening of WS2 exciton reflectance peaks in heterostructures of monolayer WS2 capped with mono- to few-layer graphene. The broadening is found to be similar for the A and B excitons and on the order of 5-10 meV. No strong dependence on the number of graphene layers was observed within experimental uncertainty. The broadening can be attributed to charge- and energy-transfer processes between the two materials, providing an observed lower bound for the corresponding time scales of 65 fs.

  19. Novel Phase Noise Reduction Method for CPW‐Based Microwave Oscillator Circuit Utilizing a Compact Planar Helical Resonator

    National Research Council Canada - National Science Library

    Hwang, Cheol Gyu; Myung, Noh Hoon


    This letter describes a compact printed helical resonator and its application to a microwave oscillator circuit implemented in coplanar waveguide (CPW) technology. The high quality (Q)‐factor and spurious...

  20. Design of a CPW-Fed Band-Notched UWB Antenna Using a Feeder-Embedded Slotline Resonator

    National Research Council Canada - National Science Library

    Abbosh, Amin M


    .... A slotline resonator is incorporated in the coplanar waveguide feeder of the antenna to act as a bandstop filter, hence enabling the rejection of any undesired band within the passband of the antenna...

  1. Microminiature optical waveguide structure and method for fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Strand, O.T.; Deri, R.J.; Pocha, M.D.


    A method for manufacturing low-cost, nearly circular cross section waveguides comprises starting with a substrate material that a molten waveguide material can not wet or coat. A thin layer is deposited of an opposite material that the molten waveguide material will wet and is patterned to describe the desired surface-contact path pedestals for a waveguide. A waveguide material, e.g., polymer or doped silica, is deposited. A resist material is deposited and unwanted excess is removed to form pattern masks. The waveguide material is etched away to form waveguide precursors and the masks are removed. Heat is applied to reflow the waveguide precursors into near-circular cross-section waveguides that sit atop the pedestals. The waveguide material naturally forms nearly circular cross sections due to the surface tension effects. After cooling, the waveguides will maintain the round shape. If the width and length are the same, then spherical ball lenses are formed. Alternatively, the pedestals can be patterned to taper along their lengths on the surface of the substrate. This will cause the waveguides to assume a conical taper after reflowing by heat. 32 figs.

  2. Microminiature optical waveguide structure and method for fabrication (United States)

    Strand, Oliver T.; Deri, Robert J.; Pocha, Michael D.


    A method for manufacturing low-cost, nearly circular cross section waveguides comprises starting with a substrate material that a molten waveguide material can not wet or coat. A thin layer is deposited of an opposite material that the molten waveguide material will wet and is patterned to describe the desired surface-contact path pedestals for a waveguide. A waveguide material, e.g., polymer or doped silica, is deposited. A resist material is deposited and unwanted excess is removed to form pattern masks. The waveguide material is etched away to form waveguide precursors and the masks are removed. Heat is applied to reflow the waveguide precursors into near-circular cross-section waveguides that sit atop the pedestals. The waveguide material naturally forms nearly circular cross sections due to the surface tension effects. After cooling, the waveguides will maintain the round shape. If the width and length are the same, then spherical ball lenses are formed. Alternatively, the pedestals can be patterned to taper along their lengths on the surface of the substrate. This will cause the waveguides to assume a conical taper after reflowing by heat.

  3. Slow light in quantum dot photonic crystal waveguides

    DEFF Research Database (Denmark)

    Nielsen, Torben Roland; Lavrinenko, Andrei; Mørk, Jesper


    A theoretical analysis of pulse propagation in a semiconductor quantum dot photonic crystal waveguide in the regime of electromagnetically induced transparency is presented. The slow light mechanism considered here is based on both material and waveguide dispersion. The group index n......(g) for the combined system is significantly enhanced relative to slow light based on purely material or waveguide dispersion....

  4. Designing large-bandwidth planar photonic crystal waveguides

    DEFF Research Database (Denmark)

    Lavrinenko, Andrei; Søndergaard, Thomas


    Our waveguide design is characterized by first of all a large bandwidth, and secondly it is characterized by a relatively high group velocity giving a better modal dispersion match with the modes of standard waveguides used for coupling light into the planar crystal waveguide (PCW). We consider t...

  5. Numerical characterization of nanopillar photonic crystal waveguides and directional couplers

    DEFF Research Database (Denmark)

    Chigrin, Dmitry N.; Lavrinenko, Andrei; Sotomayor Torres, Clivia M.


    We numerically characterize a novel type of a photonic crystal waveguide, which consists of several rows of periodically arranged dielectric cylinders. In such a nanopillar photonic crystal waveguide, light confinement is due to the total internal reflection. A nanopillar waveguide is a multimode...

  6. Waveguide BEC Interferometry with Painted Potentials (United States)

    Boshier, Malcolm; Lebedev, Vyacheslav; Samson, Carlo; Ryu, Changhyun


    Waveguide atom interferometers offer the possibility of long measurement times in a compact geometry, which can be an advantage over free space interferometers if the dephasing due to interatomic interactions can be controlled. We are investigating waveguide BEC interferometers created with the painted potential, a technique which allows for the creation and manipulation of BECs in arbitrary 2D potentials. The goal is to measure a linear acceleration of the device. The painted potential allows new approaches to the initial splitting of the BEC. For example, instead of smoothly deforming a single well potential into a double well, it is possible instead to gradually remove a weak link coupling two initially separated waveguides. This strategy should reduce excitations created in the splitting process. We are currently implementing such schemes and measuring the coherence time of the BEC after division. We will present the results of these measurements, and report progress towards measuring linear accelerations. Supported by LANL/LDRD.

  7. Quantum interference between transverse spatial waveguide modes. (United States)

    Mohanty, Aseema; Zhang, Mian; Dutt, Avik; Ramelow, Sven; Nussenzveig, Paulo; Lipson, Michal


    Integrated quantum optics has the potential to markedly reduce the footprint and resource requirements of quantum information processing systems, but its practical implementation demands broader utilization of the available degrees of freedom within the optical field. To date, integrated photonic quantum systems have primarily relied on path encoding. However, in the classical regime, the transverse spatial modes of a multi-mode waveguide have been easily manipulated using the waveguide geometry to densely encode information. Here, we demonstrate quantum interference between the transverse spatial modes within a single multi-mode waveguide using quantum circuit-building blocks. This work shows that spatial modes can be controlled to an unprecedented level and have the potential to enable practical and robust quantum information processing.

  8. Full color waveguide liquid crystal display. (United States)

    Zhou, Xiaochen; Qin, Guangkui; Wang, Long; Chen, Zhuo; Xu, Xiaoguang; Dong, Youmei; Moheghi, Alireza; Yang, Deng-Ke


    We developed a waveguide liquid crystal display from a liquid crystal (LC)/polymer composite. It does not need polarizers or color filters. It is illuminated by color LEDs installed on its edge. The light produced by the edge LEDs is coupled into the display and then waveguided through the display. When the LC is in the transparent state, the incident light is waveguided through and no light comes out of the viewing side of the display. When the LC is in the scattering state, the incident light is scattered and comes out of the display. It can be used either for transparent display or for direct view display. The composite has a submillisecond response time, and a field sequential scheme can be used to display full color images. Because the display does not need polarizers or color filters, its energy efficiency is much higher than current liquid crystal displays.

  9. Large-bandwidth planar photonic crystal waveguides

    DEFF Research Database (Denmark)

    Søndergaard, Thomas; Lavrinenko, Andrei


    A general design principle is presented for making finite-height photonic crystal waveguides that support leakage-free guidance of light over large frequency intervals. The large bandwidth waveguides are designed by introducing line defects in photonic crystal slabs, where the material in the line...... defect has appropriate dispersion properties relative to the photonic crystal slab material surrounding the line defect. A three-dimensional theoretical analysis is given for large-bandwidth waveguide designs based on a silicon-air photonic crystal slab suspended in air. In one example, the leakage......-free single-mode guidance is found for a large frequency interval covering 60% of the photonic band-gap....

  10. Cascaded Quadratic Soliton Compression in Waveguide Structures

    DEFF Research Database (Denmark)

    Guo, Hairun

    between the Kerr nonlinear effects and the dispersive effects in the medium. A Kerr-like nonlinearity is produced through the cascaded phase mismatched quadratic process, e.g. the second harmonic generation process, which can be flexibly tuned in both the sign and the amplitude, making possible a strong...... and self-defocusing Kerr effect so that the soliton is created and the soliton self-compression happens in the normal dispersion region. Meanwhile, the chromatic dispersion in the waveguide is also tunable, understood as the dispersion engineering with structural designs. Therefore, compared to commonly......-focusing Kerr effects when under the self-defocusing regime. On the other hand, CQSC in quadratic waveguides seems highly complementary to that in quadratic bulk crystals. With bulk crystals dealing with high-energy, low-repetition-rate and large-beam-size pulses, quadratic waveguides could operate low...

  11. Reconfigurable origami-inspired acoustic waveguides. (United States)

    Babaee, Sahab; Overvelde, Johannes T B; Chen, Elizabeth R; Tournat, Vincent; Bertoldi, Katia


    We combine numerical simulations and experiments to design a new class of reconfigurable waveguides based on three-dimensional origami-inspired metamaterials. Our strategy builds on the fact that the rigid plates and hinges forming these structures define networks of tubes that can be easily reconfigured. As such, they provide an ideal platform to actively control and redirect the propagation of sound. We design reconfigurable systems that, depending on the externally applied deformation, can act as networks of waveguides oriented along one, two, or three preferential directions. Moreover, we demonstrate that the capability of the structure to guide and radiate acoustic energy along predefined directions can be easily switched on and off, as the networks of tubes are reversibly formed and disrupted. The proposed designs expand the ability of existing acoustic metamaterials and exploit complex waveguiding to enhance control over propagation and radiation of acoustic energy, opening avenues for the design of a new class of tunable acoustic functional systems.

  12. Nonlinear optical model for strip plasmonic waveguides

    DEFF Research Database (Denmark)

    Lysenko, Oleg; Bache, Morten; Lavrinenko, Andrei


    This paper presents a theoretical model of nonlinear optical properties for strip plasmonic waveguides. The particular waveguides geometry that we investigate contains a gold core, adhesion layers, and silicon dioxide cladding. It is shown that the third-order susceptibility of the gold core...... significantly depends on the layer thickness and has the dominant contribution to the effective third-order susceptibility of the long-range plasmon polariton mode. This results in two nonlinear optical effects in plasmonic waveguides, which we experimentally observed and reported in [Opt. Lett. 41, 317 (2016......)]. The first effect is the nonlinear power saturation of the plasmonic mode, and the second effect is the spectral broadening of the plasmonic mode. Both nonlinear plasmonic effects can be used for practical applications and their appropriate model will be important for further developments in communication...

  13. Optical polyimides for single-mode waveguides (United States)

    Beuhler, Allyson J.; Wargowski, David A.; Kowalczyk, Tony C.; Singer, Kenneth D.


    The synthesis and optical characterization of fluorinated polyimide systems with potential use in passive waveguides and electro-optic devices is reported. The effect of fluorination on optical properties such as refractive index, birefringence, and near-infrared absorbance is reviewed in terms of optical performance requirements. Synthetic methods of tuning the refractive index in order to achieve appropriate core/cladding differentials is discussed. The relation between processing parameters and refractive index for several polyimide structures also is reported. We describe the microlithographic fabrication of a multilayer polyimide rib- type waveguide that is suitable for single mode guiding. The waveguide is fabricated using photosensitive polyimide systems via negative resist imaging. A comparison of wall profiles and resolution limits afforded by the wet-chemical patterning techniques is presented. Results on channel guide coupling, propagation, and loss are described, as well as progress in producing active guides.

  14. Lithium niobate integrated photonic crystal and waveguides (United States)

    Lim, Soon Thor; Ang, Thomas Y.-L.; Png, Ching Eng; Deng, Jun; Danner, Aaron J.


    In this work we successfully fabricated and measured PhCs patterned on a LiNbO3 APE waveguide. SIMS data indicate that after 5 hours exchange time a PE layer of 3μm can be obtained. The depth of holes was 2μm by applying a large milling current. We presented experimental characterization of the PhC waveguide and a well-defined PBG was observed from the transmission spectra. An extinction ratio was estimated to be approximately 15dB. Optical transmission results indicate that deep air holes can lead to a sharp band edge. This PhC waveguide is a good candidate for further development of an ultra-compact, low-voltage LiNbO3 modulator.

  15. Self-biased 215 MHz magnetoelectric NEMS resonator for ultra-sensitive DC magnetic field detection. (United States)

    Nan, Tianxiang; Hui, Yu; Rinaldi, Matteo; Sun, Nian X


    High sensitivity magnetoelectric sensors with their electromechanical resonance frequencies NEMS) resonator with an electromechanical resonance frequency of 215 MHz based on an AlN/(FeGaB/Al2O3) × 10 magnetoelectric heterostructure for detecting DC magnetic fields. This magnetoelectric NEMS resonator showed a high quality factor of 735, and strong magnetoelectric coupling with a large voltage tunable sensitivity. The admittance of the magnetoelectric NEMS resonator was very sensitive to DC magnetic fields at its electromechanical resonance, which led to a new detection mechanism for ultra-sensitive self-biased RF NEMS magnetoelectric sensor with a low limit of detection of DC magnetic fields of ~300 picoTelsa. The magnetic/piezoelectric heterostructure based RF NEMS magnetoelectric sensor is compact, power efficient and readily integrated with CMOS technology, which represents a new class of ultra-sensitive magnetometers for DC and low frequency AC magnetic fields.

  16. "Unmanned” optical micromanipulation using waveguide microstructures

    DEFF Research Database (Denmark)

    Bañas, Andrew Rafael; Palima, Darwin; Villangca, Mark Jayson


    that could be microfabricated, the study of how optical forces behave in such structures become useful in the emerging field of optofludics. Recently, we have shown how optically maneuverable tapered waveguide microstructures can augment beam shaping experiments by delivering strongly focused light...... be shaped more arbitrarily, engineered light deflection could lead to more control in the resulting motion. We demonstrated this principle with the autonomous translation of bent waveguides though pre-defined light tracks. In our experiment, incoming light makes a near 90 degree turn, hence the resulting...

  17. Laser written waveguide photonic quantum circuits. (United States)

    Marshall, Graham D; Politi, Alberto; Matthews, Jonathan C F; Dekker, Peter; Ams, Martin; Withford, Michael J; O'Brien, Jeremy L


    We report photonic quantum circuits created using an ultrafast laser processing technique that is rapid, requires no lithographic mask and can be used to create three-dimensional networks of waveguide devices. We have characterized directional couplers--the key functional elements of photonic quantum circuits--and found that they perform as well as lithographically produced waveguide devices. We further demonstrate high-performance interferometers and an important multi-photon quantum interference phenomenon for the first time in integrated optics. This direct-write approach will enable the rapid development of sophisticated quantum optical circuits and their scaling into three-dimensions.

  18. Improving plasmonic waveguides coupling efficiency using nanoantennas

    DEFF Research Database (Denmark)

    Andryieuski, Andrei; Malureanu, Radu; Bouillard, Jean-Sebastien


    Plasmonic waveguides bear a lot of potential for photonic applications. However, one of the challenges for implementing them in devices is the low coupling efficiency to and from optical fibers. We report on our approach to facilitate the coupling efficiency with the use of metallic nanoantennas....... The classical dipole antenna scheme can be improved by changing the nanoantenna geometry, adding constructive elements such as reflecting bars and mirrors and using arrays of antennas. The modelling designates that the coupling efficiency from a vertical fiber to a plasmonic waveguide can be improved more than...

  19. Physically correct theoretical prism waveguide coupler model. (United States)

    Liu, Tao; Samuels, Robert J


    We develop new generalized four-wave-model-based waveguide mode equations for both isotropic and anisotropic systems by taking into account the influence of the incident light. These new mode equations eliminate the inherent deficiency in the conventional waveguide model, in which the action of incident light was neglected. Further, a peak-value-search (PVS) numerical method is developed to solve the four-wave-model-based mode equations. The PVS method has significant advantages in that accurate refractive index and thickness can be obtained without prior knowledge of the thickness of the air gap.

  20. Nanoparticle sorting in silicon waveguide arrays (United States)

    Zhao, H. T.; Zhang, Y.; Chin, L. K.; Yap, P. H.; Wang, K.; Ser, W.; Liu, A. Q.


    This paper presents the optical fractionation of nanoparticles in silicon waveguide arrays. The optical lattice is generated by evanescent coupling in silicon waveguide arrays. The hotspot size is tunable by changing the refractive index of surrounding liquids. In the experiment, 0.2-μm and 0.5-μm particles are separated with a recovery rate of 95.76%. This near-field approach is a promising candidate for manipulating nanoscale biomolecules and is anticipated to benefit the biomedical applications such as exosome purification, DNA optical mapping, cell-cell interaction, etc.

  1. Localization of nonlinear excitations in curved waveguides

    DEFF Research Database (Denmark)

    Gaididei, Yu. B.; Christiansen, Peter Leth; Kevrekidis, P. G.


    Motivated by the examples of a curved waveguide embedded in a photonic crystal and cold atoms moving in a waveguide created by a spatially inhomogeneous electromagnetic field, we examine the effects of geometry in a 'quantum channel' of parabolic form. Starting with the linear case we derive exact...... as well as approximate expressions for the eigenvalues and eigenfunctions of the linear problem. We then proceed to the nonlinear setting and its stationary states in a number of limiting cases that allow for analytical treatment. The results of our analysis are used as initial conditions in direct...

  2. Quantum Dots in Photonic Crystal Waveguides

    DEFF Research Database (Denmark)

    Sollner, Immo Nathanael

    of this Thesis we discuss a novel type of photonic crystal waveguide and show its applications for on-chip quantum information processing. This structure was designed for the ecient mapping of two orthogonal circular dipole transitions to dierent propagation paths of the emitted photon, i.e. exhibits chiral...... quantum-dot-waveguide coupling. Such a structure is ideally suited for a number of applications in quantum information processing and among others we propose an on-chip spin-photon interface, a single photon transistor, and a deterministic cNOT gate....

  3. Integrated graphene based modulators enabled by interfacing plasmonic slot and silicon waveguides

    DEFF Research Database (Denmark)

    Xiao, Sanshui

    to direct more optical energy to the material interface where graphene could reside. We propose and demonstrate efficient graphene plasmonic waveguide electro-optical modulators, which are fully integrated with the silicon-on-insulator platform. We experimentally achieve the tunability of 0.13 d......Graphene has offered a new paradigm for extremely fast and active optoelectronic devices due to its unique electronic and optical properties [1]. With the combination of high-index dielectric waveguides/resonators, several integrated graphene-based optical modulators have already been demonstrated...... [2,3]. However, the optical modes in these systems are inherently strongly localized in the high-index materials, thus jeopardizing light-graphene interactions. Surface plasmon polaritons have been shown the ability to manipulate light in the nanoscale, while at the same time giving possibility...

  4. Surface-enhanced fluorescence in metal nanoparticle-doped polymer nanofibers via waveguiding excitation (United States)

    Yu, Jiaxin; Liao, Feng; Liu, Fang; Gu, Fuxing; Zeng, Heping


    We report a waveguiding excitation-based approach for surface-enhanced fluorescence. As high as 17-fold enhanced fluorescence intensity of Rhodamine 6G molecules is realized by gold nanoparticles embedded in polymer nanofibers. The enhancement results not only from the spatial confinement of light by the nanofibers but also from the wavelength match among the excitation laser, the localized surface plasmon resonance of nanoparticles, and the absorption band of dyes. On the basis of the enhancement and high-efficient waveguiding regime, the required excitation power for detectable fluorescence is decreased to the 20 nW level, which is about 50 times lower than that by free-space excitation. These fluorophore/nanoparticle-doped nanofibers may find applications in compact and energy-efficient optical devices of chemical analysis and biosensing.

  5. Photoresponse of Natural van der Waals Heterostructures. (United States)

    Ray, Kyle; Yore, Alexander E; Mou, Tong; Jha, Sauraj; Smithe, Kirby K H; Wang, Bin; Pop, Eric; Newaz, A K M


    Van der Waals heterostructures consisting of two-dimensional materials offer a platform to obtain materials by design and are very attractive owing to unique electronic states. Research on 2D van der Waals heterostructures (vdWH) has so far been focused on fabricating individually stacked atomically thin unary or binary crystals. Such systems include graphene, hexagonal boron nitride, and members of the transition metal dichalcogenide family. Here we present our experimental study of the optoelectronic properties of a naturally occurring vdWH, known as franckeite, which is a complex layered crystal composed of lead, tin, antimony, iron, and sulfur. We present here that thin film franckeite (60 nm < d < 100 nm) behaves as a narrow band gap semiconductor demonstrating a wide-band photoresponse. We have observed the band-edge transition at ∼1500 nm (∼830 meV) and high external quantum efficiency (EQE ≈ 3%) at room temperature. Laser-power-resolved and temperature-resolved photocurrent measurements reveal that the photocarrier generation and recombination are dominated by continuously distributed trap states within the band gap. To understand wavelength-resolved photocurrent, we also calculated the optical absorption properties via density functional theory. Finally, we have shown that the device has a fast photoresponse with a rise time as fast as ∼1 ms. Our study provides a fundamental understanding of the optoelectronic behavior in a complex naturally occurring vdWH, and may pave an avenue toward developing nanoscale optoelectronic devices with tailored properties.

  6. Surface oxygen vacancy induced solar light activity enhancement of a CdWO4/Bi2O2CO3 core-shell heterostructure photocatalyst. (United States)

    Yang, Chunming; Gao, Guimei; Zhang, Junjun; Liu, Ruiping; Fan, Ruicheng; Zhao, Ming; Wang, Yongwang; Gan, Shucai


    A CdWO4/Bi2O2CO3 core-shell heterostructure photocatalyst was fabricated via a facile two-step hydrothermal process. Flower-like Bi2O2CO3 was synthesized and functioned as the cores on which CdWO4 nanorods were coated as the shells. Photoluminescence (PL) spectra and electron paramagnetic resonance (EPR) demonstrate that the CdWO4/Bi2O2CO3 core-shell heterostructure photocatalyst possesses a large amount of oxygen vacancies, which induce defect levels in the band gap and help to broaden light absorption. The photocatalyst exhibits enhanced photocatalytic activity for Rhodamine B (RhB), methylene blue (MB), methyl orange (MO), and colorless contaminant phenol degradation under solar light irradiation. The heterostructured CdWO4/Bi2O2CO3 core-shell photocatalyst shows drastically enhanced photocatalytic properties compared to the pure CdWO4 and Bi2O2CO3. This remarkable enhancement is attributed to the following three factors: (1) the presence of oxygen vacancies induces defect levels in the band gap and increases the visible light absorption; (2) intimate interfacial interactions derived from the core-shell heterostructure; and (3) the formation of the n-n junction between the CdWO4 and Bi2O2CO3. The mechanism is further explored by analyzing its heterostructure and determining the role of active radicals. The construction of high-performance photocatalysts with oxygen vacancies and core-shell heterostructures has great potential for degradation of refractory contaminants in water with solar light irradiation.

  7. Analogue of electromagnetically-induced-transparency based on graphene nanotube waveguide (United States)

    Wei, Buzheng; Jian, Shuisheng


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

  8. Broadband high reflectivity in subwavelength-grating slab waveguides. (United States)

    Tian, Hao; Cui, Xuan; Du, Yan; Tan, Peng; Shi, Guang; Zhou, Zhongxiang


    We computationally study a subwavelength dielectric grating structure, show that slab waveguide modes can be used to obtain broadband high reflectivity, and analyze how slab waveguide modes influence reflection. A structure showing interference between Fabry-Perot modes, slab waveguide modes, and waveguide array modes is designed with ultra-broadband high reflectivity. Owing to the coupling of guided modes, the region with reflectivity R > 0.99 has an ultra-high bandwidth (Δf / ̅f > 30%). The incident-angle region with R > 0.99 extends over a range greater than 40°. Moreover, an asymmetric waveguide structure with a semiconductor substrate is studied.

  9. Optimization of optical losses in waveguide component manufacturing (United States)

    Swatowski, Brandon W.; Hyer, Maynard G.; Shepherd, Debra A.; Weidner, W. Ken; Degroot, Jon V.


    We report on the development and optimization of key performance properties of multimode silicone polymer waveguides, manufactured for 850 nm optical propagation. These developments are based on photopatternable, mechanically flexible, low-loss, gradient index waveguides. Cross sectional waveguide core sizes ranging from 40 μm x 50 μm to greater than 60 μm x 60 μm are assessed with optical analysis of component losses such as crossings and coupling between OM4 fiber and waveguide. Assessments of these values, led to optimization of waveguide size and lower total optical system losses. Methods of manufacture, preparation, and analysis are discussed in detail along with performance results.

  10. Gallium Nitride Nanowires and Heterostructures: Toward Color-Tunable and White-Light Sources. (United States)

    Kuykendall, Tevye R; Schwartzberg, Adam M; Aloni, Shaul


    Gallium-nitride-based light-emitting diodes have enabled the commercialization of efficient solid-state lighting devices. Nonplanar nanomaterial architectures, such as nanowires and nanowire-based heterostructures, have the potential to significantly improve the performance of light-emitting devices through defect reduction, strain relaxation, and increased junction area. In addition, relaxation of internal strain caused by indium incorporation will facilitate pushing the emission wavelength into the red. This could eliminate inefficient phosphor conversion and enable color-tunable emission or white-light emission by combining blue, green, and red sources. Utilizing the waveguiding modes of the individual nanowires will further enhance light emission, and the properties of photonic structures formed by nanowire arrays can be implemented to improve light extraction. Recent advances in synthetic methods leading to better control over GaN and InGaN nanowire synthesis are described along with new concept devices leading to efficient white-light emission. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Under-Coupling Whispering Gallery Mode Resonator Applied to Resonant Micro-Optic Gyroscope

    Directory of Open Access Journals (Sweden)

    Kun Qian


    Full Text Available As an important sensing element, the whispering gallery mode resonator (WGMR parameters seriously affect the resonant micro-optic gyroscope (RMOG performance. This work proposes an under-coupling resonator to improve the resonator’s Q value and to optimize the coupling coefficient to maximize the RMOG’s sensitivity. GeO2-doped silica waveguide-type resonators with different coupling coefficients were simulated, designed, fabricated and tested. An under-coupling ring resonator with a quality factor of 10 million is reported. The RMOG system was built based on this resonator and the scale factor was tested on a uniaxial high-precision rotating platform. Experimental results show that this resonator could improve the RMOG sensitivity by five times.

  12. Integrated graphene waveguide modulators based on low-loss plasmonic slot waveguides

    DEFF Research Database (Denmark)

    Xiao, Sanshui


    Graphene based electro-absorption modulators involving dielectric optical waveguides have been recently explored, suffering however from weak graphene-light interaction. Surface plasmon polaritons enable light concentration within subwavelength regions opening thereby new avenues for strengthening...... graphene-light interactions. I present novel integrated graphene plasmonic waveguide modulator showing high modulation depth and low insertion loss, thus giving a promising way to miniaturize the device without jeopardizing the performance of the device....

  13. Strongly Confined Spoof Surface Plasmon Polaritons Waveguiding Enabled by Planar Staggered Plasmonic Waveguides (United States)

    Ye, Longfang; Xiao, Yifan; Liu, Yanhui; Zhang, Liang; Cai, Guoxiong; Liu, Qing Huo


    We demonstrate a novel route to achieving highly efficient and strongly confined spoof surface plasmon polaritons (SPPs) waveguides at subwavelength scale enabled by planar staggered plasmonic waveguides (PSPWs). The structure of these new waveguides consists of an ultrathin metallic strip with periodic subwavelength staggered double groove arrays supported by a flexible dielectric substrate, leading to unique staggered EM coupling and waveguiding phenomenon. The spoof SPP propagation properties, including dispersion relations and near field distributions, are numerically investigated. Furthermore, broadband coplanar waveguide (CPW) to planar staggered plasmonic waveguide (PSPW) transitions are designed to achieve smooth momentum matching and highly efficient spoof SPP mode conversion. By applying these transitions, a CPW-PSPW-CPW structure is designed, fabricated and measured to verify the PSPW’s propagation performance at microwave frequencies. The investigation results show the proposed PSPWs have excellent performance of deep subwavelength spoof SPPs confinement, long propagation length and low bend loss, as well as great design flexibility to engineer the propagation properties by adjusting their geometry dimensions and material parameters. Our work opens up a new avenue for development of various advanced planar integrated plasmonic devices and circuits in microwave and terahertz regimes.

  14. Dual computational basis qubit in semiconductor heterostructures (United States)

    Gilbert, M. J.; Akis, R.; Ferry, D. K.


    Advances in quantum computing have revealed computing capabilities that threaten to render many of the public encryption codes useless against the hacking potential for a quantum-mechanical-based computing system. This potential forces the study of viable methods to keep vital information secure from third-party eavesdropping. In this letter, we propose a coupled electronic waveguide device to create a qubit with two computational bases. The characteristics we have obtained by simulating such devices suggest a possible way of implementing quantum cryptography in semiconductor device architectures.

  15. Optical touch screen based on waveguide sensing

    DEFF Research Database (Denmark)

    Pedersen, Henrik Chresten; Jakobsen, Michael Linde; Hanson, Steen Grüner


    We disclose a simple, optical touch screen technique based on a planar injection molded polymer waveguide, a single laser, and a small linear detector array. The solution significantly reduces the complexity and cost as compared to existing optical touch technologies. Force detection of a touching...

  16. Ultrafast Nonlinear Signal Processing in Silicon Waveguides

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo; Mulvad, Hans Christian Hansen; Hu, Hao


    We describe recent demonstrations of exploiting highly nonlinear silicon waveguides for ultrafast optical signal processing. We describe wavelength conversion and serial-to-parallel conversion of 640 Gbit/s data signals and 1.28 Tbit/s demultiplexing and all-optical sampling....

  17. Spatial solitons in nonlinear liquid waveguides

    Indian Academy of Sciences (India)

    Spatial solitons are studied in a planar waveguide filled with nonlinear liquids. Spectral and spatial measurements for different geometries and input power of the laser beam show the influence of different nonlinear effects as stimulated scatterings on the soliton propagation and in particular on the beam polarization.

  18. Slow-light vortices in periodic waveguides

    DEFF Research Database (Denmark)

    Sukhorukov, Andrey A.; Ha, Sangwoo; Desyatnikov, Anton S.


    We reveal that the reduction of the group velocity of light in periodic waveguides is generically associated with the presence of vortex energy flows. We show that the energy flows are gradually frozen for slow-light at the Brillouin zone edge, whereas vortices persist for slow-light states havin...

  19. Planar photonic crystal waveguides in silicon oxynitride

    DEFF Research Database (Denmark)

    Liu, Haoling; Frandsen, Lars Hagedorn; Borel, Peter Ingo

    , at visible wavelengths they absorb light very strongly. In contrary, silicon oxynitride (SiON) glasses offer high transparency down to blue and ultraviolet wavelengths. Thus, SiON photonic crystal waveguides can open for new possibilities, e.g., within sensing and life sciences. We have fabricated Si...

  20. Spatial solitons in nonlinear liquid waveguides

    Indian Academy of Sciences (India)

    Packard [15]. We present a study of the main experimental results we obtained in the last few years in nonlinear liquid waveguides. Polarization properties are particularly attractive, opening the door to applications in the field of optical switching and ...

  1. Hybrid modes in a square corrugated waveguide

    Energy Technology Data Exchange (ETDEWEB)

    Ohkubo, K.


    By using two scalar eigenfunctions, electric and magnetic fields in the rectangular (or square) corrugated waveguide are analyzed. In a rectangular corrugated waveguide, the boundary conditions on two corrugated and two smooth walls can be satisfied to excite the hybrid mode. In a highly oversized waveguide where the wavelength of dominant mode is close to that in vacuum, two smooth walls can be exchanged with the corrugated walls because the boundary condition at this walls is satisfied approximately. The replacement is possible due to almost no penetration of the electromagnetic fields into the gap of the replaced walls when the direction of main electric field is parallel to the gap of replaced walls. This characteristic enables us to rotate the polarization of the hybrid mode in the oversized square waveguide with all four corrugated walls and is applicable to the remote steering antenna for electron cyclotron heating in the ITER. For a beam injection larger than the critical angle in this antenna, excited higher modes are at a considerably different wavelength from that in vacuum and result in the dissatisfaction of boundary conditions due to millimeter-wave penetration into corrugation gaps in replaced walls. (author)

  2. UV Defined Nanoporous Liquid Core Waveguides

    DEFF Research Database (Denmark)

    Christiansen, Mads Brøkner; Gopalakrishnan, Nimi; Ndoni, Sokol


    Nanoporous liquid core waveguides, where both core and cladding are made from the same material, are presented. The nanoporous polymer used is intrinsically hydrophobic, but selective UV exposure enables it to infiltrate with an aqueous solution, thus raising the refractive index from 1.26 to 1...

  3. Energy flow in photonic crystal waveguides

    DEFF Research Database (Denmark)

    Søndergaard, Thomas; Dridi, Kim


    Theoretical and numerical investigations of energy flow in photonic crystal waveguides made of line defects and branching points are presented. It is shown that vortices of energy flow may occur, and the net energy flow along: the line defect is described via the effective propagation velocity...

  4. Subwavelength line imaging using plasmonic waveguides

    NARCIS (Netherlands)

    Podoliak, N.; Horak, P.; Prangsma, Jord; Pinkse, Pepijn Willemszoon Harry


    We investigate the subwavelength imaging capacity of a 2-D fanned-out plasmonic waveguide array, formed by air channels surrounded by gold metal layers for operation at near-infrared wavelengths, via finite-element simulations. High resolution is achieved on one side of the device by tapering down

  5. Bandwidth engineering of photonic crystal waveguide bends

    DEFF Research Database (Denmark)

    Borel, Peter Ingo; Frandsen, Lars Hagedorn; Harpøth, Anders


    An effective design principle has been applied to photonic crystal waveguide bends fabricated in silicon-on-insulator material using deep UV lithography resulting in a large increase in the low-loss bandwidth of the bends. Furthermore, it is experimentally demonstrated that the absolute bandwidth...

  6. Multilayer Graphene for Waveguide Terahertz Modulator

    DEFF Research Database (Denmark)

    Khromova, I.; Andryieuski, Andrei; Lavrinenko, Andrei


    We study terahertz to infrared electromagnetic properties of multilayer graphene/dielectric artificial medium and present a novel concept of terahertz modulation at midinfrared wavelengths. This approach allows the realization of high-speed electrically controllable terahertz modulators based...... on hollow waveguide sections filled with multilayer graphene....

  7. Transforming guided waves with metamaterial waveguide cores (United States)

    Viaene, S.; Ginis, V.; Danckaert, J.; Tassin, P.


    Metamaterials make use of subwavelength building blocks to enhance our control on the propagation of light. To determine the required material properties for a given functionality, i.e., a set of desired light flows inside a metamaterial device, metamaterial designs often rely on a geometrical design tool known as transformation optics. In recent years, applications in integrated photonics motivated several research groups to develop two-dimensional versions of transformation optics capable of routing surface waves along graphene-dielectric and metal-dielectric interfaces. Although guided electromagnetic waves are highly relevant to applications in integrated optics, no consistent transformation-optical framework has so far been developed for slab waveguides. Indeed, the conventional application of transformation optics to dielectric slab waveguides leads to bulky three-dimensional devices with metamaterial implementations both inside and outside of the waveguide's core. In this contribution, we develop a transformationoptical framework that still results in thin metamaterial waveguide devices consisting of a nonmagnetic metamaterial core of varying thickness [Phys. Rev. B 93.8, 085429 (2016)]. We numerically demonstrate the effectiveness and versatility of our equivalence relations with three crucial functionalities: a beam bender, a beam splitter and a conformal lens. Our devices perform well on a qualitative (comparison of fields) and quantitative (comparison of transmitted power) level compared to their bulky counterparts. As a result, the geometrical toolbox of transformation optics may lead to a plethora of integrated metamaterial devices to route guided waves along optical chips.

  8. Two-dimensional Kagome photonic bandgap waveguide

    DEFF Research Database (Denmark)

    Nielsen, Jens Bo; Søndergaard, Thomas; Libori, Stig E. Barkou


    The transverse-magnetic photonic-bandgap-guidance properties are investigated for a planar two-dimensional (2-D) Kagome waveguide configuration using a full-vectorial plane-wave-expansion method. Single-moded well-localized low-index guided modes are found. The localization of the optical modes...

  9. Ge/Si core/multi shell heterostructure FETs

    Energy Technology Data Exchange (ETDEWEB)

    Picraux, Samuel T [Los Alamos National Laboratory; Dayeh, Shadi A [Los Alamos National Laboratory


    Concentric heterostructured materials provide numerous design opportunities for engineering strain and interfaces, as well as tailoring energy band-edge combinations for optimal device performance. Key to the realization of such novel device concepts is the complete understanding and full control over their growth, crystal structure, and hetero-epitaxy. We report here on a new route for synthesizing Ge/Si core/multi-shell heterostructure nanowires that eliminate Au seed diffusion on the nanowire sidewalls by engineering the interface energy density difference. We show that such control over core/shell synthesis enable experimental realization of heterostructure FET devices beyond those available in the literature with enhanced transport characteristics. We provide a side-by-side comparison on the transport properties of Ge/Si core/multi-shell nanowires grown with and without Au diffusion and demonstrate heterostructure FETs with drive currents that are {approx} 2X higher than record results for p-type FETs.

  10. Engineering charge transport by heterostructuring solution-processed semiconductors (United States)

    Voznyy, Oleksandr; Sutherland, Brandon R.; Ip, Alexander H.; Zhitomirsky, David; Sargent, Edward H.


    Solution-processed semiconductor devices are increasingly exploiting heterostructuring — an approach in which two or more materials with different energy landscapes are integrated into a composite system. Heterostructured materials offer an additional degree of freedom to control charge transport and recombination for more efficient optoelectronic devices. By exploiting energetic asymmetry, rationally engineered heterostructured materials can overcome weaknesses, augment strengths and introduce emergent physical phenomena that are otherwise inaccessible to single-material systems. These systems see benefit and application in two distinct branches of charge-carrier manipulation. First, they influence the balance between excitons and free charges to enhance electron extraction in solar cells and photodetectors. Second, they promote radiative recombination by spatially confining electrons and holes, which increases the quantum efficiency of light-emitting diodes. In this Review, we discuss advances in the design and composition of heterostructured materials, consider their implementation in semiconductor devices and examine unexplored paths for future advancement in the field.

  11. Magnetic Heterostructures Advances and Perspectives in Spinstructures and Spintransport

    CERN Document Server

    Bader, Samuel D


    Magnetic heterostructures constitute an important field in magnetism and nanotechnology, which has developed over the past fifteen years due to important advances in epitaxial- growth techniques and lithographic processes. Magnetic heterostructures combine different physical properties which do not exist in nature. Examples are semiconductors/ferromagnets, superconductors/ferromagnets, and ferromagnets/antiferromagnets. These combinations display rich and novel physical properties different from those that exit in any single one of them. Interlayer exchange coupling, exchange bias, proximity effects, giant magneto-resistance, tunneling magneto-resistance, spininjection and spintransport are examples of new physical phenomena that rely on the combination of different materials layers. Since the literature on magnetic heterostructures is widely spread and highly specialized, the situation calls for a book that provides an overview of the basics and the state of the art of magnetic heterostructures. These contri...

  12. Frustration-driven C4symmetric order in a naturally-heterostructured superconductor Sr2VO3FeAs. (United States)

    Ok, Jong Mok; Baek, S-H; Hoch, C; Kremer, R K; Park, S Y; Ji, Sungdae; Büchner, B; Park, J-H; Hyun, S I; Shim, J H; Bang, Yunkyu; Moon, E G; Mazin, I I; Kim, Jun Sung


    A subtle balance between competing interactions in iron-based superconductors (FeSCs) can be tipped by additional interfacial interactions in a heterostructure, often inducing exotic phases with unprecedented properties. Particularly when the proximity-coupled layer is magnetically active, rich phase diagrams are expected in FeSCs, but this has not been explored yet. Here, using high-accuracy 75 As and 51 V nuclear magnetic resonance measurements, we investigate an electronic phase that emerges in the FeAs layer below T 0  ~ 155 K of Sr 2 VO 3 FeAs, a naturally assembled heterostructure of an FeSC and a Mott-insulating vanadium oxide. We find that frustration of the otherwise dominant Fe stripe and V Neel fluctuations via interfacial coupling induces a charge/orbital order in the FeAs layers, without either static magnetism or broken C 4 symmetry, while suppressing the Neel antiferromagnetism in the SrVO 3 layers. These findings demonstrate that the magnetic proximity coupling stabilizes a hidden order in FeSCs, which may also apply to other strongly correlated heterostructures.

  13. Organic heterostructures deposited by MAPLE on AZO substrate (United States)

    Socol, M.; Preda, N.; Stanculescu, A.; Breazu, C.; Florica, C.; Stanculescu, F.; Iftimie, S.; Girtan, M.; Popescu-Pelin, G.; Socol, G.


    Organic heterostructures based on poly(3-hexylthiophene) (P3HT) and fullerene (C60) as blends or multilayer were deposited on Al:ZnO (AZO) by Matrix-Assisted Pulsed Laser Evaporation (MAPLE) technique. The AZO layers were obtained by Pulsed Laser Deposition (PLD) on glass substrate, the high quality of the films being reflected by the calculated figure of merit. The organic heterostructures were investigated from morphological, optical and electrical point of view by atomic force microscopy (AFM), UV-vis spectroscopy, photoluminescence (PL) and current-voltage (I-V) measurements, respectively. The increase of the C60 content in the blend heterostructure has as result a high roughness. Compared with the multilayer heterostructure, those based on blends present an improvement in the electrical properties. Under illumination, the highest current value was recorded for the heterostructure based on the blend with the higher C60 amount. The obtained results showed that MAPLE is a useful technique for the deposition of the organic heterostructures on AZO as transparent conductor electrode.

  14. Quantum and field effects of oxide heterostructures

    DEFF Research Database (Denmark)

    Trier, Felix

    . In these multi-plexed devices, several inputs aretranslated into several outputs through the multiple physical functionalities.A highly prominent example of such an oxide interface is the one between LaAlO3 and SrTiO3. Although both LaAlO3 and SrTiO3 in the bulk are electrically insulating and non...... aspects of sample preparation will initially be covered. Here, the growth of amorphous-LaAlO3 on SrTiO3 will be addressed in a modified pulsed laser deposition setup. This is followed by an investigation of two high-electron mobility interfaces in SrTiO3-based heterostructures. Specifically...

  15. Coherent Interlayer Tunneling and Negative Differential Resistance with High Current Density in Double Bilayer Graphene-WSe2 Heterostructures. (United States)

    Burg, G William; Prasad, Nitin; Fallahazad, Babak; Valsaraj, Amithraj; Kim, Kyounghwan; Taniguchi, Takashi; Watanabe, Kenji; Wang, Qingxiao; Kim, Moon J; Register, Leonard F; Tutuc, Emanuel


    We demonstrate gate-tunable resonant tunneling and negative differential resistance between two rotationally aligned bilayer graphene sheets separated by bilayer WSe2. We observe large interlayer current densities of 2 and 2.5 μA/μm2 and peak-to-valley ratios approaching 4 and 6 at room temperature and 1.5 K, respectively, values that are comparable to epitaxially grown resonant tunneling heterostructures. An excellent agreement between theoretical calculations using a Lorentzian spectral function for the two-dimensional (2D) quasiparticle states, and the experimental data indicates that the interlayer current stems primarily from energy and in-plane momentum conserving 2D-2D tunneling, with minimal contributions from inelastic or non-momentum-conserving tunneling. We demonstrate narrow tunneling resonances with intrinsic half-widths of 4 and 6 meV at 1.5 and 300 K, respectively.

  16. Investigation of the field dependent spin structure of exchange coupled magnetic heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Gurieva, Tatiana


    This thesis describes the investigation of the field dependent magnetic spin structure of an antiferromagnetically (AF) coupled Fe/Cr heterostructure sandwiched between a hardmagnetic FePt buffer layer and a softmagnetic Fe top layer. The depth-resolved experimental studies of this system were performed via Magneto-optical Kerr effect (MOKE), Vibrating Sample Magnetometry (VSM) and various measuring methods based on nuclear resonant scattering (NRS) technique. Nucleation and evolution of the magnetic spiral structure in the AF coupled Fe/Cr multilayer structure in an azimuthally rotating external magnetic field were observed using NRS. During the experiment a number of time-dependent magnetic side effects (magnetic after-effect, domain-wall creep effect) caused by the non-ideal structure of a real sample were observed and later explained. Creation of the magnetic spiral structure in rotating external magnetic field was simulated using a one-dimensional micromagnetic model.The cross-sectional magnetic X-ray diffraction technique was conceived and is theoretically described in the present work. This method allows to determine the magnetization state of an individual layer in the magnetic heterostructure. It is also applicable in studies of the magnetic structure of tiny samples where conventional x-ray reflectometry fails.

  17. Chemical potential and tunneling in bilayer graphene using double bilayer graphene heterostructures (United States)

    Tutuc, Emanuel


    Vertical heterostructures consisting of atomic layers separated by insulators can open a window to explore the role of electron interaction in these materials, otherwise not accessible in single layer devices. We describe here one such heterostructure, consisting of two bilayer graphene flakes separated by a hexagonal boron-nitride dielectric. Using the top layer as a resistively detected Kelvin probe we map the chemical potential of the bottom bilayer graphene as a function of electron density, perpendicular magnetic field, and transverse electric field. At zero magnetic field the chemical potential reveals a strongly non-linear dependence on density, with an electric field induced energy gap at charge neutrality. The data allow a direct measurement of the electric field-induced bandgap at zero magnetic field, the orbital Landau level energies, and the broken symmetry quantum Hall state gaps in high magnetic fields. In samples where the two layers are rotationally aligned the interlayer tunneling current measured as a function of interlayer bias reveals a gate-tunable negative differential resistance thanks to momentum conserving tunneling. Remarkably, the resonance width has a weak temperature dependence in the range 1.5 K to 300 K. Work done in collaboration with K. Lee, B. Fallahazad, S. Kang, J. Xue, D. C. Dillen, K. Kim, L. F. Register, S. K. Banerjee, T. Taniguchi, and K. Watanabe. This work supported by the Office of Naval Research, the Nanoelectronics Research Initiative SWAN center, and Intel Corp.

  18. Magnetoelectric imaging of multiferroic heterostructures (Presentation Recording) (United States)

    Ghidini, Massimo; Lesaine, Arnaud; Zhu, Bonan; Moya, Xavier; Yan, Wenjing; Crossley, Sam; Nair, Bhasi; Mansell, Rhodri; Cowburn, Russell P.; Barnes, Crispin H. W.; Kronast, Florian; Valencia, Sergio; Maccherozzi, Francesco; Dhesi, Sarnjeet S.; Mathur, Neil


    Electrical control of magnetism has been demonstrated in multiferroic compounds and ferromagnetic semiconductors, but electrical switching of a substantial net magnetization at room temperature has not been demonstrated in these materials. This goal has instead been achieved in heterostructures comprising ferromagnetic films in which electrically driven magnetic changes arise due to strain or exchange bias from ferroic substrates, or due to charge effects induced by a gate. However, previous work focused on electrical switching of an in-plane magnetization or involved the assistance of applied magnetic fields. In heterostructures made of juxtaposed ferroelectric and ferromagnetic layers, we have shown electrical control with no applied magnetic field of the perpendicular magnetization of small features [1] and of magnetic stripe domains patterns [2]. Here we investigate Ni81Fe19 films on ferroelectric substrates with and without buffer layers of Cu, whose presence precludes charge-mediated coupling. Ni81Fe19 has virtually zero magnetostriction, but sufficiently thin films show large magnetostriction, and thus, on increasing film thickness through the threshold for zero magnetostriction, we have seeked the crossover from charge- to strain-mediated coupling. We will then show that strain associated with the motion of 90°- ferroelectric domain walls in a BaTiO3 substrate, can switch the magnetization of an array of overlying single-domain Ni dots. [1] M. Ghidini, R. Pellicelli, J. L. Prieto, X. Moya, J. Soussi, J. Briscoe, S. Dunn and N. D. Mathur, Nature Communications 4 (2013) 1453. [2] M. Ghidini, F.Maccherozzi, X. Moya, L. C. Phillips, W.Yan, J. Soussi, N. Métallier, M.Vickers, , N. -J.Steinke, R. Mansell, C. H. W. Barnes, S. S. Dhesi, and N. D. Mathur, Adv. Mater.doi: 10.1002/adma.201404799 (2015).

  19. Sideband Resolved Cooling of a Nanomechanical Resonator Parametrically Coupled to a Microwave Resonator (United States)

    Rocheleau, Tristan; Ndukum, Tchefor; Hertzberg, Jared; Schwab, Keith


    We have fabricated a nanostructure formed by a radio-frequency nanomechanical (NEMS) resonator capacitively coupled to an aluminum 5 GHz superconducting, co-planar waveguide (CPW) resonator with 50 φ characteristic impedance.By driving this coupled system at a frequency φpump=φCPW- φNEMS, we demonstrate back action cooling effects of a single NEMS mode achieving cooling from temperatures of 100mK to resonator which we expect to be capable of cooling the NEMS close to ground state.

  20. Formation of femtosecond pulses during the SRS self-transformation of optical solitons in fiber-optic waveguides (United States)

    Serkin, V. N.


    A physical model is proposed which describes the SRS self-transformation of femtosecond pulses in a nonlinear dispersing medium. The dynamics of the decomposition of the coupled states of solitons in fiber-optic waveguides to femtosecond wave packets is analyzed. An indirect method for measuring the lifetime of the excited state of vibrational resonances in glass is proposed which is based on an analysis of the correlation functions of luminescence.