A bi-stable nanoelectromechanical non-volatile memory based on van der Waals force

NASA Astrophysics Data System (ADS)

Soon, Bo Woon; Jiaqiang Ng, Eldwin; Qian, You; Singh, Navab; Julius Tsai, Minglin; Lee, Chengkuo

2013-07-01

By using complementary-metal-oxide-semiconductor processes, a silicon based bi-stable nanoelectromechanical non-volatile memory is fabricated and characterized. The main feature of this device is an 80 nm wide and 3 μm high silicon nanofin (SiNF) of a high aspect ratio (1:35). The switching mechanism is realized by electrostatic actuation between two lateral electrodes, i.e., terminals. Bi-stable hysteresis behavior is demonstrated when the SiNF maintains its contact to one of the two terminals by leveraging on van der Waals force even after voltage bias is turned off. The compelling results indicate that this design is promising for realization of high density non-volatile memory application due to its nano-scale footprint and zero on-hold power consumption.

Review: Electrostatically actuated nanobeam-based nanoelectromechanical switches – materials solutions and operational conditions

PubMed Central

Jasulaneca, Liga; Kosmaca, Jelena; Meija, Raimonds; Andzane, Jana

2018-01-01

This review summarizes relevant research in the field of electrostatically actuated nanobeam-based nanoelectromechanical (NEM) switches. The main switch architectures and structural elements are briefly described and compared. Investigation methods that allow for exploring coupled electromechanical interactions as well as studies of mechanically or electrically induced effects are covered. An examination of the complex nanocontact behaviour during various stages of the switching cycle is provided. The choice of the switching element and the electrode is addressed from the materials perspective, detailing the benefits and drawbacks for each. An overview of experimentally demonstrated NEM switching devices is provided, and together with their operational parameters, the reliability issues and impact of the operating environment are discussed. Finally, the most common NEM switch failure modes and the physical mechanisms behind them are reviewed and solutions proposed. PMID:29441272

Carbon Nanotube Based Nano-Electro-Mechanical Systems (NEMS)

NASA Technical Reports Server (NTRS)

Han, Jie; Dai, Hongjie; Saini, Subhash

1998-01-01

Carbon nanotubes (CNT) enable nanoelectromechanical systems (NEMS) because of their inherent nanostructure, intrinsic electric conductivity and mechanical resilience. The collaborative work between Stanford (experiment) and NASA Ames (theory and simulation) has made progress in two types of CNT based NEMS for nanoelectronics and sensor applications. The CNT tipped scanning probe microscopy (SPM) is a NEMS in which CNT tips are used for nanoscale probing, imaging and manipulating. It showed great improvement in probing surfaces and biological systems over conventional tips. We have recently applied it to write (lithography) and read (image) uniform SiO2 lines on large Si surface area at speed up to 0.5 mm per s. Preliminary work using approximately 10 nm multiwall nanotube tips produced approximately 10 nm structures and showed that the CNT tips didn't wear down when crashed as conventional tips often do. This presents a solution to the long standing tip-wear problem in SPM nanolithography. We have also explored potential of CNT tips in imaging DNA in water. Preliminary experiment using 10 nm CNT tips reached 5 nm resolution. The 1 nm nanolithography and 1 nm DNA imaging can be expected by using approximately 1 nm CNT tips. In contrast to CNT tipped SPM, we also fabricated CNT devices on silicon wafer in which CNTs connect patterned metallic lines on SiO2/Si by a simple chemical vapor deposition process. Using conventional lithography for silicon wafer, we have been able to obtain CNT based transistors and sensors. Investigations of the CNT NEMS as physical, biological and chemical sensors are in progress and will be discussed.

Large scale integration of CVD-graphene based NEMS with narrow distribution of resonance parameters

NASA Astrophysics Data System (ADS)

Arjmandi-Tash, Hadi; Allain, Adrien; (Vitto Han, Zheng; Bouchiat, Vincent

2017-06-01

We present a novel method for the fabrication of the arrays of suspended micron-sized membranes, based on monolayer pulsed-CVD graphene. Such devices are the source of an efficient integration of graphene nano-electro-mechanical resonators, compatible with production at the wafer scale using standard photolithography and processing tools. As the graphene surface is continuously protected by the same polymer layer during the whole process, suspended graphene membranes are clean and free of imperfections such as deposits, wrinkles and tears. Batch fabrication of 100 μm-long multi-connected suspended ribbons is presented. At room temperature, mechanical resonance of electrostatically-actuated devices show narrow distribution of their characteristic parameters with high quality factor and low effective mass and resonance frequencies, as expected for low stress and adsorbate-free membranes. Upon cooling, a sharp increase of both resonant frequency and quality factor is observed, enabling to extract the thermal expansion coefficient of CVD graphene. Comparison with state-of-the-art graphene NEMS is presented.

Ultra low power consumption for self-oscillating nanoelectromechanical systems constructed by contacting two nanowires.

PubMed

Barois, T; Ayari, A; Vincent, P; Perisanu, S; Poncharal, P; Purcell, S T

2013-04-10

We report here the observation of a new self-oscillation mechanism in nanoelectromechanical systems (NEMS). A highly resistive nanowire was positioned to form a point-contact at a chosen vibration node of a silicon carbide nanowire resonator. Spontaneous and robust mechanical oscillations arise when a sufficient DC voltage is applied between the two nanowires. An original model predicting the threshold voltage is used to estimate the piezoresistivity of the point-contact in agreement with the observations. The measured input power is in the pW-range which is the lowest reported value for such systems. The simplicity of the contacting procedure and the low power consumption open a new route for integrable and low-loss self-excited NEMS devices.

Tunneling Nanoelectromechanical Switches Based on Compressible Molecular Thin Films.

PubMed

Niroui, Farnaz; Wang, Annie I; Sletten, Ellen M; Song, Yi; Kong, Jing; Yablonovitch, Eli; Swager, Timothy M; Lang, Jeffrey H; Bulović, Vladimir

2015-08-25

Abrupt switching behavior and near-zero leakage current of nanoelectromechanical (NEM) switches are advantageous properties through which NEMs can outperform conventional semiconductor electrical switches. To date, however, typical NEMs structures require high actuation voltages and can prematurely fail through permanent adhesion (defined as stiction) of device components. To overcome these challenges, in the present work we propose a NEM switch, termed a "squitch," which is designed to electromechanically modulate the tunneling current through a nanometer-scale gap defined by an organic molecular film sandwiched between two electrodes. When voltage is applied across the electrodes, the generated electrostatic force compresses the sandwiched molecular layer, thereby reducing the tunneling gap and causing an exponential increase in the current through the device. The presence of the molecular layer avoids direct contact of the electrodes during the switching process. Furthermore, as the layer is compressed, the increasing surface adhesion forces are balanced by the elastic restoring force of the deformed molecules which can promote zero net stiction and recoverable switching. Through numerical analysis, we demonstrate the potential of optimizing squitch design to enable large on-off ratios beyond 6 orders of magnitude with operation in the sub-1 V regime and with nanoseconds switching times. Our preliminary experimental results based on metal-molecule-graphene devices suggest the feasibility of the proposed tunneling switching mechanism. With optimization of device design and material engineering, squitches can give rise to a broad range of low-power electronic applications.

Characterization of SiO{sub 2}/SiN{sub x} gate insulators for graphene based nanoelectromechanical systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tóvári, E.; Csontos, M., E-mail: csontos@dept.phy.bme.hu; Kriváchy, T.

2014-09-22

The structural and magnetotransport characterization of graphene nanodevices exfoliated onto Si/SiO{sub 2}/SiN{sub x} heterostructures are presented. Improved visibility of the deposited flakes is achieved by optimal tuning of the dielectric film thicknesses. The conductance of single layer graphene Hall-bar nanostructures utilizing SiO{sub 2}/SiN{sub x} gate dielectrics were characterized in the quantum Hall regime. Our results highlight that, while exhibiting better mechanical and chemical stability, the effect of non-stoichiometric SiN{sub x} on the charge carrier mobility of graphene is comparable to that of SiO{sub 2}, demonstrating the merits of SiN{sub x} as an ideal material platform for graphene based nanoelectromechanical applications.

Parametric amplification in MoS2 drum resonator.

PubMed

Prasad, Parmeshwar; Arora, Nishta; Naik, A K

2017-11-30

Parametric amplification is widely used in diverse areas from optics to electronic circuits to enhance low level signals by varying relevant system parameters. Parametric amplification has also been performed in several micro-nano resonators including nano-electromechanical system (NEMS) resonators based on a two-dimensional (2D) material. Here, we report the enhancement of mechanical response in a MoS 2 drum resonator using degenerate parametric amplification. We use parametric pumping to modulate the spring constant of the MoS 2 resonator and achieve a 10 dB amplitude gain. We also demonstrate quality factor enhancement in the resonator with parametric amplification. We investigate the effect of cubic nonlinearity on parametric amplification and show that it limits the gain of the mechanical resonator. Amplifying ultra-small displacements at room temperature and understanding the limitations of the amplification in these devices is key for using these devices for practical applications.

Nanoscale mass detection based on vibrating piezoelectric ultrathin films under thermo-electro-mechanical loads

NASA Astrophysics Data System (ADS)

Asemi, H. R.; Asemi, S. R.; Farajpour, A.; Mohammadi, M.

2015-04-01

The potential applications of piezoelectric nanofilms (PNFs) and double-piezoelectric-nanofilm (DPNF) systems as nanoelectromechanical mass sensors are examined. The PNFs carrying multiple nanoparticles at arbitrary locations are modeled as rectangular nonlocal plates with attached concentrated masses. Using the nonlocal elasticity theory and Hamilton's principle, the differential equations of motion are derived for both PNF-based and DPNF-based nanosensors. The influences of small scale, initial stress and temperature change on the frequency shifts of the nanoelectromechanical sensors are taken into consideration. Explicit expressions are derived for the resonance frequencies of the nanosensors by employing the Galerkin method. The present results show that when the value of nonlocal parameter decreases, the frequency shifts of piezoelectric nanosensors increase. Further, the frequency shifts of DPNF-based mass sensors are always greater than those of PNF-based mass sensors. The present work would be helpful in the design of nanoelectromechanical mass sensors using PNFs.

Precise control of coupling strength in photonic molecules over a wide range using nanoelectromechanical systems

PubMed Central

Du, Han; Zhang, Xingwang; Chen, Guoqiang; Deng, Jie; Chau, Fook Siong; Zhou, Guangya

2016-01-01

Photonic molecules have a range of promising applications including quantum information processing, where precise control of coupling strength is critical. Here, by laterally shifting the center-to-center offset of coupled photonic crystal nanobeam cavities, we demonstrate a method to precisely and dynamically control the coupling strength of photonic molecules through integrated nanoelectromechanical systems with a precision of a few GHz over a range of several THz without modifying the nature of their constituent resonators. Furthermore, the coupling strength can be tuned continuously from negative (strong coupling regime) to zero (weak coupling regime) and further to positive (strong coupling regime) and vice versa. Our work opens a door to the optimization of the coupling strength of photonic molecules in situ for the study of cavity quantum electrodynamics and the development of efficient quantum information devices. PMID:27097883

VHF NEMS-CMOS piezoresistive resonators for advanced sensing applications

NASA Astrophysics Data System (ADS)

Arcamone, Julien; Dupré, Cécilia; Arndt, Grégory; Colinet, Eric; Hentz, Sébastien; Ollier, Eric; Duraffourg, Laurent

2014-10-01

This work reports on top-down nanoelectromechanical resonators, which are among the smallest resonators listed in the literature. To overcome the fact that their electromechanical transduction is intrinsically very challenging due to their very high frequency (100 MHz) and ultimate size (each resonator is a 1.2 μm long, 100 nm wide, 20 nm thick silicon beam with 100 nm long and 30 nm wide piezoresistive lateral nanowire gauges), they have been monolithically integrated with an advanced fully depleted SOI CMOS technology. By advantageously combining the unique benefits of nanomechanics and nanoelectronics, this hybrid NEMS-CMOS device paves the way for novel breakthrough applications, such as NEMS-based mass spectrometry or hybrid NEMS/CMOS logic, which cannot be fully implemented without this association.

Nano-electromechanical switch-CMOS hybrid technology and its applications.

PubMed

Lee, B H; Hwang, H J; Cho, C H; Lim, S K; Lee, S Y; Hwang, H

2011-01-01

Si-based CMOS technology is facing a serious challenge in terms of power consumption and variability. The increasing costs associated with physical scaling have motivated a search for alternative approaches. Hybridization of nano-electromechanical (NEM)-switch and Si-based CMOS devices has shown a theoretical feasibility for power management, but a huge technical gap must be bridged before a nanoscale NEM switch can be realized due to insufficient material development and the limited understanding of its reliability characteristics. These authors propose the use of a multilayer graphene as a nanoscale cantilever material for a nanoscale NEM switchwith dimensions comparable to those of the state-of-the-art Si-based CMOS devices. The optimal thickness for the multilayer graphene (about five layers) is suggested based on an analytical model. Multilayer graphene can provide the highest Young's modulus among the known electrode materials and a yielding strength that allows more than 15% bending. Further research on material screening and device integration is needed, however, to realize the promises of the hybridization of NEM-switch and Si-based CMOS devices.

Lead zirconate titanate nanoscale patterning by ultraviolet-based lithography lift-off technique for nano-electromechanical system applications.

PubMed

Guillon, Samuel; Saya, Daisuke; Mazenq, Laurent; Costecalde, Jean; Rèmiens, Denis; Soyer, Caroline; Nicu, Liviu

2012-09-01

The advantage of using lead zirconate titanate (PbZr(0.54)Ti(0.46)O(3)) ceramics as an active material in nanoelectromechanical systems (NEMS) comes from its relatively high piezoelectric coefficients. However, its integration within a technological process is limited by the difficulty of structuring this material with submicrometer resolution at the wafer scale. In this work, we develop a specific patterning method based on optical lithography coupled with a dual-layer resist process. The main objective is to obtain sub-micrometer features by lifting off a 100-nm-thick PZT layer while preserving the material's piezoelectric properties. A subsequent result of the developed method is the ability to stack several layers with a lateral resolution of few tens of nanometers, which is mandatory for the fabrication of NEMS with integrated actuation and read-out capabilities.

A Low-Voltage and High Uniformity Nano-Electro-Mechanical System Tunable Color Filter Based on Subwavelength Grating

NASA Astrophysics Data System (ADS)

Honma, Hiroaki; Takahashi, Kazuhiro; Ishida, Makoto; Sawada, Kazuaki

2012-11-01

This paper reports on the construction of a nano-electro-mechanical system (NEMS) tunable color filter based on a subwavelength grating with high color uniformity and a low drive voltage. We recently proposed a ground-voltage-ground (GVG)-type tunable color filter with a parallel-plate actuator with three pairs of electrodes to decrease the crosstalk due to the electrostatic attractive force between each pair of actuators. Our finite element method (FEM) simulation results indicate that the drive voltage is decreased by 10 V, as compared to that of the previously reported GV type. The proposed structure was fabricated using a silicon-on-insulator (SOI) wafer. The color tuning capability of the device was demonstrated by applying a drive voltage of 6.7 V. The reflected light intensity was decreased by 34% at a wavelength of 680 nm. Color uniformity was also obtained in the filter area by reducing the variation of the displacement on the one-dimensional actuator arrays.

Self-Biased 215MHz Magnetoelectric NEMS Resonator for Ultra-Sensitive DC Magnetic Field Detection

NASA Astrophysics Data System (ADS)

Nan, Tianxiang; Hui, Yu; Rinaldi, Matteo; Sun, Nian X.

2013-06-01

High sensitivity magnetoelectric sensors with their electromechanical resonance frequencies < 200 kHz have been recently demonstrated using magnetostrictive/piezoelectric magnetoelectric heterostructures. In this work, we demonstrate a novel magnetoelectric nano-electromechanical systems (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.

Ultra-low power hydrogen sensing based on a palladium-coated nanomechanical beam resonator

NASA Astrophysics Data System (ADS)

Henriksson, Jonas; Villanueva, Luis Guillermo; Brugger, Juergen

2012-07-01

Hydrogen sensing is essential to ensure safety in near-future zero-emission fuel cell powered vehicles. Here, we present a novel hydrogen sensor based on the resonant frequency change of a nanoelectromechanical clamped-clamped beam. The beam is coated with a Pd layer, which expands in the presence of H2, therefore generating a stress build-up that causes the frequency of the device to drop. The devices are able to detect H2 concentrations below 0.5% within 1 s of the onset of the exposure using only a few hundreds of pW of power, matching the industry requirements for H2 safety sensors. In addition, we investigate the strongly detrimental effect that relative humidity (RH) has on the Pd responsivity to H2, showing that the response is almost nullified at about 70% RH. As a remedy for this intrinsic limitation, we applied a mild heating current through the beam, generating a few μW of power, whereby the responsivity of the sensors is fully restored and the chemo-mechanical process is accelerated, significantly decreasing response times. The sensors are fabricated using standard processes, facilitating their eventual mass-production.Hydrogen sensing is essential to ensure safety in near-future zero-emission fuel cell powered vehicles. Here, we present a novel hydrogen sensor based on the resonant frequency change of a nanoelectromechanical clamped-clamped beam. The beam is coated with a Pd layer, which expands in the presence of H2, therefore generating a stress build-up that causes the frequency of the device to drop. The devices are able to detect H2 concentrations below 0.5% within 1 s of the onset of the exposure using only a few hundreds of pW of power, matching the industry requirements for H2 safety sensors. In addition, we investigate the strongly detrimental effect that relative humidity (RH) has on the Pd responsivity to H2, showing that the response is almost nullified at about 70% RH. As a remedy for this intrinsic limitation, we applied a mild heating

Neutral Mass Spectrometry of Mega-Dalton Particles with Single-Particle Resolution using a Nano-Electromechanical System

NASA Astrophysics Data System (ADS)

Kelber, Scott; Hanay, Mehmet; Naik, Akshay; Chi, Derrick; Hentz, Sebastien; Bullard, Caryn; Collinet, Eric; Duraffourg, Laurent; Roukes, Michael

2012-02-01

Nanoelectromechanical systems (NEMS) enable mass sensing with unprecedented sensitivity and mass dynamic range. Previous works have relied on statistical analysis of multiple landing events to assemble mass spectra. Here we demonstrate the utility of using multiple modes of the NEMS device in determining the mass of individual molecules landing on the NEMS. Analyte particles in vapor form are produced using matrix assisted laser desorption ionization. Resonant frequencies of the first two modes of a single NEMS device, placed in close proximity to the analyte source, are tracked using parallel phase locked loops. Each analyte molecule landing on the NEMS generates a distinct frequency shift in the two modes. These time correlated frequency jumps are used to evaluate the mass of each analyte particle landing on the NEMS and thus generate mass spectra. We present the latest experimental results using this scheme and also demonstrate the utility for mass spectrometry of large biomolecules. This NEMS-Mass Spec. system offers a new tool for structural biology and pathology for the analysis of large proteins, protein complexes, and viruses.

Piezoelectric actuated micro-resonators based on the growth of diamond on aluminum nitride thin films.

PubMed

Hees, J; Heidrich, N; Pletschen, W; Sah, R E; Wolfer, M; Williams, O A; Lebedev, V; Nebel, C E; Ambacher, O

2013-01-18

Unimorph heterostructures based on piezoelectric aluminum nitride (AlN) and diamond thin films are highly desirable for applications in micro- and nanoelectromechanical systems. In this paper, we present a new approach to combine thin conductive boron-doped as well as insulating nanocrystalline diamond (NCD) with sputtered AlN films without the need for any buffer layers between AlN and NCD or polishing steps. The zeta potentials of differently treated nanodiamond (ND) particles in aqueous colloids are adjusted to the zeta potential of AlN in water. Thereby, the nucleation density for the initial growth of diamond on AlN can be varied from very low (10(8) cm(-2)), in the case of hydrogen-treated ND seeding particles, to very high values of 10(11) cm(-2) for oxidized ND particles. Our approach yielding high nucleation densities allows the growth of very thin NCD films on AlN with thicknesses as low as 40 nm for applications such as microelectromechanical beam resonators. Fabricated piezo-actuated micro-resonators exhibit enhanced mechanical properties due to the incorporation of boron-doped NCD films. Highly boron-doped NCD thin films which replace the metal top electrode offer Young's moduli of more than 1000 GPa.

Piezoresistive silicon nanowire resonators as embedded building blocks in thick SOI

NASA Astrophysics Data System (ADS)

Nasr Esfahani, Mohammad; Kilinc, Yasin; Çagatay Karakan, M.; Orhan, Ezgi; Hanay, M. Selim; Leblebici, Yusuf; Erdem Alaca, B.

2018-04-01

The use of silicon nanowire resonators in nanoelectromechanical systems for new-generation sensing and communication devices faces integration challenges with higher-order structures. Monolithic and deterministic integration of such nanowires with the surrounding microscale architecture within the same thick crystal is a critical aspect for the improvement of throughput, reliability and device functionality. A monolithic and IC-compatible technology based on a tuned combination of etching and protection processes was recently introduced yielding silicon nanowires within a 10 μ m-thick device layer. Motivated by its success, the implications of the technology regarding the electromechanical resonance are studied within a particular setting, where the resonator is co-fabricated with all terminals and tuning electrodes. Frequency response is measured via piezoresistive readout with frequency down-mixing. Measurements indicate mechanical resonance with frequencies as high as 100 MHz exhibiting a Lorentzian behavior with proper transition to nonlinearity, while Allan deviation on the order of 3-8 ppm is achieved. Enabling the fabrication of silicon nanowires in thick silicon crystals using conventional semiconductor manufacturing, the present study thus demonstrates an alternative pathway to bottom-up and thin silicon-on-insulator approaches for silicon nanowire resonators.

Ultra-low power hydrogen sensing based on a palladium-coated nanomechanical beam resonator.

PubMed

Henriksson, Jonas; Villanueva, Luis Guillermo; Brugger, Juergen

2012-08-21

Hydrogen sensing is essential to ensure safety in near-future zero-emission fuel cell powered vehicles. Here, we present a novel hydrogen sensor based on the resonant frequency change of a nanoelectromechanical clamped-clamped beam. The beam is coated with a Pd layer, which expands in the presence of H(2), therefore generating a stress build-up that causes the frequency of the device to drop. The devices are able to detect H(2) concentrations below 0.5% within 1 s of the onset of the exposure using only a few hundreds of pW of power, matching the industry requirements for H(2) safety sensors. In addition, we investigate the strongly detrimental effect that relative humidity (RH) has on the Pd responsivity to H(2), showing that the response is almost nullified at about 70% RH. As a remedy for this intrinsic limitation, we applied a mild heating current through the beam, generating a few μW of power, whereby the responsivity of the sensors is fully restored and the chemo-mechanical process is accelerated, significantly decreasing response times. The sensors are fabricated using standard processes, facilitating their eventual mass-production.

Carbon Nanofiber-Based, High-Frequency, High-Q, Miniaturized Mechanical Resonators

NASA Technical Reports Server (NTRS)

Kaul, Anupama B.; Epp, Larry W.; Bagge, Leif

2011-01-01

High Q resonators are a critical component of stable, low-noise communication systems, radar, and precise timing applications such as atomic clocks. In electronic resonators based on Si integrated circuits, resistive losses increase as a result of the continued reduction in device dimensions, which decreases their Q values. On the other hand, due to the mechanical construct of bulk acoustic wave (BAW) and surface acoustic wave (SAW) resonators, such loss mechanisms are absent, enabling higher Q-values for both BAW and SAW resonators compared to their electronic counterparts. The other advantages of mechanical resonators are their inherently higher radiation tolerance, a factor that makes them attractive for NASA s extreme environment planetary missions, for example to the Jovian environments where the radiation doses are at hostile levels. Despite these advantages, both BAW and SAW resonators suffer from low resonant frequencies and they are also physically large, which precludes their integration into miniaturized electronic systems. Because there is a need to move the resonant frequency of oscillators to the order of gigahertz, new technologies and materials are being investigated that will make performance at those frequencies attainable. By moving to nanoscale structures, in this case vertically oriented, cantilevered carbon nanotubes (CNTs), that have larger aspect ratios (length/thickness) and extremely high elastic moduli, it is possible to overcome the two disadvantages of both bulk acoustic wave (BAW) and surface acoustic wave (SAW) resonators. Nano-electro-mechanical systems (NEMS) that utilize high aspect ratio nanomaterials exhibiting high elastic moduli (e.g., carbon-based nanomaterials) benefit from high Qs, operate at high frequency, and have small force constants that translate to high responsivity that results in improved sensitivity, lower power consumption, and im - proved tunablity. NEMS resonators have recently been demonstrated using topdown

Applications and Methods of Operating a Three-dimensional Nano-electro-mechanical Resonator and Related Devices

NASA Technical Reports Server (NTRS)

Kaul, Anupama B. (Inventor); Epp, Larry W. (Inventor); Bagge, Leif (Inventor)

2013-01-01

Carbon nanofiber resonator devices, methods for use, and applications of said devices are disclosed. Carbon nanofiber resonator devices can be utilized in or as high Q resonators. Resonant frequency of these devices is a function of configuration of various conducting components within these devices. Such devices can find use, for example, in filtering and chemical detection.

Nonlinear Dynamics of Nanomechanical Resonators

NASA Astrophysics Data System (ADS)

Ramakrishnan, Subramanian; Gulak, Yuiry; Sundaram, Bala; Benaroya, Haym

2007-03-01

Nanoelectromechanical systems (NEMS) offer great promise for many applications including motion and mass sensing. Recent experimental results suggest the importance of nonlinear effects in NEMS, an issue which has not been addressed fully in theory. We report on a nonlinear extension of a recent analytical model by Armour et al [1] for the dynamics of a single-electron transistor (SET) coupled to a nanomechanical resonator. We consider the nonlinear resonator motion in both (a) the Duffing and (b) nonlinear pendulum regimes. The corresponding master equations are derived and solved numerically and we consider moment approximations as well. In the Duffing case with hardening stiffness, we observe that the resonator is damped by the SET at a significantly higher rate. In the cases of softening stiffness and the pendulum, there exist regimes where the SET adds energy to the resonator. To our knowledge, this is the first instance of a single model displaying both negative and positive resonator damping in different dynamical regimes. The implications of the results for SET sensitivity as well as for, as yet unexplained, experimental results will be discussed. 1. Armour et al. Phys.Rev.B (69) 125313 (2004).

Nanoelectromechanical digital logic circuits using curved cantilever switches with amorphous-carbon-coated contacts

NASA Astrophysics Data System (ADS)

Ayala, Christopher L.; Grogg, Daniel; Bazigos, Antonios; Bleiker, Simon J.; Fernandez-Bolaños, Montserrat; Niklaus, Frank; Hagleitner, Christoph

2015-11-01

Nanoelectromechanical (NEM) switches have the potential to complement or replace traditional CMOS transistors in the area of ultra-low-power digital electronics. This paper reports the demonstration of prototype circuits including the first 3-stage ring oscillator built using cell-level digital logic elements based on curved NEM switches. The ring oscillator core occupies an area of 30 μm × 10 μm using 6 NEM switches. Each NEM switch device has a footprint of 5 μm × 3 μm, an air gap of 60 μm and is coated with amorphous carbon (a-C) for reliable operation. The ring oscillator operates at a frequency of 6.7 MHz, and confirms the simulated inverter propagation delay of 25 ns. The successful fabrication and measurement of this demonstrator are key milestones on the way towards an optimized, scaled technology with sub-nanosecond switching times, lower operating voltages and VLSI implementation.

Mechanical Signature of Heat Generated in a Current-Driven Ferromagnetic Resonance System

NASA Astrophysics Data System (ADS)

Cho, Sung Un; Jo, Myunglae; Park, Seondo; Lee, Jae-Hyun; Yang, Chanuk; Kang, Seokwon; Park, Yun Daniel

2017-07-01

In a current-driven ferromagnetic resonance (FMR) system, heat generated by time-dependent magnetoresistance effects, caused by magnetization precession, cannot be overlooked. Here, we describe the generated heat by magnetization motion under electric current in a freestanding nanoelectromechanical resonator fashioned from a permalloy (Py )/Pt bilayer. By piezoresistive transduction of Pt, the mechanical mode is electrically detected at room temperature and the internal heat in Py excluding thermoelectric effects is quantified as a shift of the mechanical resonance. We find that the measured spectral shifts correspond to the FMR, which is further verified from the spin-torque FMR measurement. Furthermore, the angular dependence of the mechanical reaction on an applied magnetic field reveals that the full accounting of FMR heat dissipation requires the time-dependent magnetoresistance effect.

Performance of monolayer graphene nanomechanical resonators with electrical readout.

PubMed

Chen, Changyao; Rosenblatt, Sami; Bolotin, Kirill I; Kalb, William; Kim, Philip; Kymissis, Ioannis; Stormer, Horst L; Heinz, Tony F; Hone, James

2009-12-01

The enormous stiffness and low density of graphene make it an ideal material for nanoelectromechanical applications. Here, we demonstrate the fabrication and electrical readout of monolayer graphene resonators, and test their response to changes in mass and temperature. The devices show resonances in the megahertz range, and the strong dependence of resonant frequency on applied gate voltage can be fitted to a membrane model to yield the mass density and built-in strain of the graphene. Following the removal and addition of mass, changes in both density and strain are observed, indicating that adsorbates impart tension to the graphene. On cooling, the frequency increases, and the shift rate can be used to measure the unusual negative thermal expansion coefficient of graphene. The quality factor increases with decreasing temperature, reaching approximately 1 x 10(4) at 5 K. By establishing many of the basic attributes of monolayer graphene resonators, the groundwork for applications of these devices, including high-sensitivity mass detectors, is put in place.

Nano-Electro-Mechanical (NEM) Relay Devices and Technology for Ultra-Low Energy Digital Integrated Circuits

DTIC Science & Technology

2013-05-01

number. 1. REPORT DATE 01 MAY 2013 2. REPORT TYPE 3. DATES COVERED 00-00- 2013 to 00-00- 2013 4. TITLE AND SUBTITLE Nano-Electro-Mechanical (NEM...18 Copyright © 2013 , by the author( s ). All rights reserved. Permission to make digital or hard copies of all or part of this work for personal or...E. Ismail, S .-H. Lo, G. A. Sai- Halasz, R . G. Viswanathan, H.-J. C. Wann, S . J. Wind, and H.- S . Wong, “CMOS scaling into the nanometer regime

Energy efficient circuit design using nanoelectromechanical relays

NASA Astrophysics Data System (ADS)

Venkatasubramanian, Ramakrishnan

Nano-electromechanical (NEM) relays are a promising class of emerging devices that offer zero off-state leakage and behave like an ideal switch. Recent advances in planar fabrication technology have demonstrated that microelectromechanical (MEMS) scale miniature relays could be manufactured reliably and could be used to build fully functional, complex integrated circuits. The zero leakage operation of relays has renewed the interest in relay based low power logic design. This dissertation explores circuit architectures using NEM relays and NEMS-CMOS heterogeneous integration. Novel circuit topologies for sequential logic, memory, and power management circuits have been proposed taking into consideration the NEM relay device properties and optimizing for energy efficiency and area. In nanoscale electromechanical devices, dispersion forces like Van der Waals' force (vdW) affect the pull-in stability of the relay devices significantly. Verilog-A electromechanical model of the suspended gate relay operating at 1V with a nominal air gap of 5 - 10nm has been developed taking into account all the electrical, mechanical and dispersion effects. This dissertation explores different relay based latch and flip-flop topologies. It has been shown that as few as 4 relay cells could be used to build flip-flops. An integrated voltage doubler based flip flop that improves the performance by 2X by overdriving Vgb has been proposed. Three NEM relay based parallel readout memory bitcell architectures have been proposed that have faster access time, and remove the reliability issues associated with previously reported serial readout architectures. A paradigm shift in design of power switches using NEM relays is proposed. An interesting property of the relay device is that the ON state resistance (Ron) of the NEM relay switch is constant and is insensitive to the gate slew rate. This coupled with infinite OFF state resistance (Roff ) offers significant area and power advantages over CMOS

Anomalous resonance in a nanomechanical biosensor

PubMed Central

Gupta, Amit K.; Nair, Pradeep R.; Akin, Demir; Ladisch, Michael R.; Broyles, Steve; Alam, Muhammad A.; Bashir, Rashid

2006-01-01

The decrease in resonant frequency (−Δωr) of a classical cantilever provides a sensitive measure of the mass of entities attached on its surface. This elementary phenomenon has been the basis of a new class of bio-nanomechanical devices as sensing components of integrated microsystems that can perform rapid, sensitive, and selective detection of biological and biochemical entities. Based on classical analysis, there is a widespread perception that smaller sensors are more sensitive (sensitivity ≈ −0.5ωr/mC, where mC is the mass of the cantilever), and this notion has motivated scaling of biosensors to nanoscale dimensions. In this work, we show that the response of a nanomechanical biosensor is far more complex than previously anticipated. Indeed, in contrast to classical microscale sensors, the resonant frequencies of the nanosensor may actually decrease or increase after attachment of protein molecules. We demonstrate theoretically and experimentally that the direction of the frequency change arises from a size-specific modification of diffusion and attachment kinetics of biomolecules on the cantilevers. This work may have broad impact on microscale and nanoscale biosensor design, especially when predicting the characteristics of bio-nanoelectromechanical sensors functionalized with biological capture molecules. PMID:16938886

Fabrication and characterization of GaN nanowire doubly clamped resonators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maliakkal, Carina B., E-mail: carina@tifr.res.in; Mathew, John P.; Hatui, Nirupam

2015-09-21

Gallium nitride (GaN) nanowires (NWs) have been intensely researched as building blocks for nanoscale electronic and photonic device applications; however, the mechanical properties of GaN nanostructures have not been explored in detail. The rigidity, thermal stability, and piezoelectric properties of GaN make it an interesting candidate for nano-electromechanical systems. We have fabricated doubly clamped GaN NW electromechanical resonators on sapphire using electron beam lithography and estimated the Young's modulus of GaN from resonance frequency measurements. For wires of triangular cross section with side ∼90 nm, we obtained values for the Young's modulus to be about 218 and 691 GPa, which are ofmore » the same order of magnitude as the values reported for bulk GaN. We also discuss the role of residual strain in the nanowire on the resonant frequency and the orientation dependence of the Young's modulus in wurtzite crystals.« less

Nanomechanical silicon resonators with intrinsic tunable gain and sub-nW power consumption.

PubMed

Bartsch, Sebastian T; Lovera, Andrea; Grogg, Daniel; Ionescu, Adrian M

2012-01-24

Nanoelectromechanical systems (NEMS) as integrated components for ultrasensitive sensing, time keeping, or radio frequency applications have driven the search for scalable nanomechanical transduction on-chip. Here, we present a hybrid silicon-on-insulator platform for building NEM oscillators in which fin field effect transistors (FinFETs) are integrated into nanomechanical silicon resonators. We demonstrate transistor amplification and signal mixing, coupled with mechanical motion at very high frequencies (25-80 MHz). By operating the transistor in the subthreshold region, the power consumption of resonators can be reduced to record-low nW levels, opening the way for the parallel operation of hundreds of thousands of NEM oscillators. The electromechanical charge modulation due to the field effect in a resonant transistor body constitutes a scalable nanomechanical motion detection all-on-chip and at room temperature. The new class of tunable NEMS represents a major step toward their integration in resonator arrays for applications in sensing and signal processing. © 2011 American Chemical Society

Nano-electro-mechanical pump: Giant pumping of water in carbon nanotubes

NASA Astrophysics Data System (ADS)

Farimani, Amir Barati; Heiranian, Mohammad; Aluru, Narayana R.

2016-05-01

A fully controllable nano-electro-mechanical device that can pump fluids at nanoscale is proposed. Using molecular dynamics simulations, we show that an applied electric field to an ion@C60 inside a water-filled carbon nanotube can pump water with excellent efficiency. The key physical mechanism governing the fluid pumping is the conversion of electrical energy into hydrodynamic flow with efficiencies as high as 64%. Our results show that water can be compressed up to 7% higher than its bulk value by applying electric fields. High flux of water (up to 13,000 molecules/ns) is obtained by the electro-mechanical, piston-cylinder-like moving mechanism of the ion@C60 in the CNT. This large flux results from the piston-like mechanism, compressibility of water (increase in density of water due to molecular ordering), orienting dipole along the electric field and efficient electrical to mechanical energy conversion. Our findings can pave the way towards efficient energy conversion, pumping of fluids at nanoscale, and drug delivery.

Nano-electro-mechanical pump: Giant pumping of water in carbon nanotubes.

PubMed

Farimani, Amir Barati; Heiranian, Mohammad; Aluru, Narayana R

2016-05-19

A fully controllable nano-electro-mechanical device that can pump fluids at nanoscale is proposed. Using molecular dynamics simulations, we show that an applied electric field to an ion@C60 inside a water-filled carbon nanotube can pump water with excellent efficiency. The key physical mechanism governing the fluid pumping is the conversion of electrical energy into hydrodynamic flow with efficiencies as high as 64%. Our results show that water can be compressed up to 7% higher than its bulk value by applying electric fields. High flux of water (up to 13,000 molecules/ns) is obtained by the electro-mechanical, piston-cylinder-like moving mechanism of the ion@C60 in the CNT. This large flux results from the piston-like mechanism, compressibility of water (increase in density of water due to molecular ordering), orienting dipole along the electric field and efficient electrical to mechanical energy conversion. Our findings can pave the way towards efficient energy conversion, pumping of fluids at nanoscale, and drug delivery.

Nano-electro-mechanical pump: Giant pumping of water in carbon nanotubes

PubMed Central

Farimani, Amir Barati; Heiranian, Mohammad; Aluru, Narayana R.

2016-01-01

A fully controllable nano-electro-mechanical device that can pump fluids at nanoscale is proposed. Using molecular dynamics simulations, we show that an applied electric field to an ion@C60 inside a water-filled carbon nanotube can pump water with excellent efficiency. The key physical mechanism governing the fluid pumping is the conversion of electrical energy into hydrodynamic flow with efficiencies as high as 64%. Our results show that water can be compressed up to 7% higher than its bulk value by applying electric fields. High flux of water (up to 13,000 molecules/ns) is obtained by the electro-mechanical, piston-cylinder-like moving mechanism of the ion@C60 in the CNT. This large flux results from the piston-like mechanism, compressibility of water (increase in density of water due to molecular ordering), orienting dipole along the electric field and efficient electrical to mechanical energy conversion. Our findings can pave the way towards efficient energy conversion, pumping of fluids at nanoscale, and drug delivery. PMID:27193507

Single-crystal diamond nanomechanical resonators with quality factors exceeding one million

NASA Astrophysics Data System (ADS)

Tao, Y.; Boss, J. M.; Moores, B. A.; Degen, C. L.

2014-04-01

Diamond has gained a reputation as a uniquely versatile material, yet one that is intricate to grow and process. Resonating nanostructures made of single-crystal diamond are expected to possess excellent mechanical properties, including high-quality factors and low dissipation. Here we demonstrate batch fabrication and mechanical measurements of single-crystal diamond cantilevers with thickness down to 85 nm, thickness uniformity better than 20 nm and lateral dimensions up to 240 μm. Quality factors exceeding one million are found at room temperature, surpassing those of state-of-the-art single-crystal silicon cantilevers of similar dimensions by roughly an order of magnitude. The corresponding thermal force noise for the best cantilevers is ~5·10-19 N Hz-1/2 at millikelvin temperatures. Single-crystal diamond could thus directly improve existing force and mass sensors by a simple substitution of resonator material. Presented methods are easily adapted for fabrication of nanoelectromechanical systems, optomechanical resonators or nanophotonic devices that may lead to new applications in classical and quantum science.

Hexagonal boron nitride nanomechanical resonators with spatially visualized motion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Xu-Qian; Lee, Jaesung; Feng, Philip X. -L.

Atomic layers of hexagonal boron nitride (h-BN) crystal are excellent candidates for structural materials as enabling ultrathin, two-dimensional (2D) nanoelectromechanical systems (NEMS) due to the outstanding mechanical properties and very wide bandgap (5.9 eV) of h-BN. In this work, we report the experimental demonstration of h-BN 2D nanomechanical resonators vibrating at high and very high frequencies (from ~ 5 to ~ 70 MHz), and investigations of the elastic properties of h-BN by measuring the multimode resonant behavior of these devices. First, we demonstrate a dry-transferred doubly clamped h-BN membrane with ~ 6.7 nm thickness, the thinnest h-BN resonator known tomore » date. In addition, we fabricate circular drumhead h-BN resonators with thicknesses ranging from ~ 9 to 292 nm, from which we measure up to eight resonance modes in the range of ~ 18 to 35 MHz. Combining measurements and modeling of the rich multimode resonances, we resolve h-BN’s elastic behavior, including the transition from membrane to disk regime, with built-in tension ranging from 0.02 to 2 N m -1. The Young’s modulus of h-BN is determined to be EY≈392 GPa from the measured resonances. The ultrasensitive measurements further reveal subtle structural characteristics and mechanical properties of the suspended h-BN diaphragms, including anisotropic built-in tension and bulging, thus suggesting guidelines on how these effects can be exploited for engineering multimode resonant functions in 2D NEMS transducers.« less

Hexagonal boron nitride nanomechanical resonators with spatially visualized motion

DOE PAGES

Zheng, Xu-Qian; Lee, Jaesung; Feng, Philip X. -L.

2017-07-31

Atomic layers of hexagonal boron nitride (h-BN) crystal are excellent candidates for structural materials as enabling ultrathin, two-dimensional (2D) nanoelectromechanical systems (NEMS) due to the outstanding mechanical properties and very wide bandgap (5.9 eV) of h-BN. In this work, we report the experimental demonstration of h-BN 2D nanomechanical resonators vibrating at high and very high frequencies (from ~ 5 to ~ 70 MHz), and investigations of the elastic properties of h-BN by measuring the multimode resonant behavior of these devices. First, we demonstrate a dry-transferred doubly clamped h-BN membrane with ~ 6.7 nm thickness, the thinnest h-BN resonator known tomore » date. In addition, we fabricate circular drumhead h-BN resonators with thicknesses ranging from ~ 9 to 292 nm, from which we measure up to eight resonance modes in the range of ~ 18 to 35 MHz. Combining measurements and modeling of the rich multimode resonances, we resolve h-BN’s elastic behavior, including the transition from membrane to disk regime, with built-in tension ranging from 0.02 to 2 N m -1. The Young’s modulus of h-BN is determined to be EY≈392 GPa from the measured resonances. The ultrasensitive measurements further reveal subtle structural characteristics and mechanical properties of the suspended h-BN diaphragms, including anisotropic built-in tension and bulging, thus suggesting guidelines on how these effects can be exploited for engineering multimode resonant functions in 2D NEMS transducers.« less

A review on nanomechanical resonators and their applications in sensors and molecular transportation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arash, Behrouz; Rabczuk, Timon, E-mail: timon.rabczuk@uni-weimar.de; Jiang, Jin-Wu

2015-06-15

Nanotechnology has opened a new area in science and engineering, leading to the development of novel nano-electromechanical systems such as nanoresonators with ultra-high resonant frequencies. The ultra-high-frequency resonators facilitate wide-ranging applications such as ultra-high sensitive sensing, molecular transportation, molecular separation, high-frequency signal processing, and biological imaging. This paper reviews recent studies on dynamic characteristics of nanoresonators. A variety of theoretical approaches, i.e., continuum modeling, molecular simulations, and multiscale methods, in modeling of nanoresonators are reviewed. The potential application of nanoresonators in design of sensor devices and molecular transportation systems is introduced. The essence of nanoresonator sensors for detection of atomsmore » and molecules with vibration and wave propagation analyses is outlined. The sensitivity of the resonator sensors and their feasibility in detecting different atoms and molecules are particularly discussed. Furthermore, the applicability of molecular transportation using the propagation of mechanical waves in nanoresonators is presented. An extended application of the transportation methods for building nanofiltering systems with ultra-high selectivity is surveyed. The article aims to provide an up-to-date review on the mechanical properties and applications of nanoresonators, and inspire additional potential of the resonators.« less

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Tong; Chau, Fook Siong; Zhou, Guangya, E-mail: mpezgy@nus.edu.sg

2015-11-30

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

Dynamics-Enabled Nanoelectromechanical Systems (NEMS) Oscillators

DTIC Science & Technology

2014-06-01

it becomes strongly nonlinear, and thus constitutes an archetypal candidate for nonlinear engineering • its fundamental resonant frequency...width of spectral peaks of atomic force microscopy (AFM) resonators as they are brought close to a surface. 39 Approved for public release...alternating current AD Allan Deviation AFM atomic force microscopy AFRL Air Force Research Laboratory AlN aluminum nitride APN Anomalous Phase

FOREWORD: Focus on Novel Nanoelectromechanical 3D Structures: Fabrication and Properties Focus on Novel Nanoelectromechanical 3D Structures: Fabrication and Properties

NASA Astrophysics Data System (ADS)

Yamada, Shooji; Yamaguchi, Hiroshi; Ishihara, Sunao

2009-06-01

Microelectromechanical systems (MEMS) are widely used small electromechanical systems made of micrometre-sized components. Presently, we are witnessing a transition from MEMS to nanoelectromechanical systems (NEMS), which comprise devices integrating electrical and mechanical functionality on the nanoscale and offer new exciting applications. Similarly to MEMS, NEMS typically include a central transistor-like nanoelectronic unit for data processing, as well as mechanical actuators, pumps, and motors; and they may combine with physical, biological and chemical sensors. In the transition from MEMS to NEMS, component sizes need to be reduced. Therefore, many fabrication methods previously developed for MEMS are unsuitable for the production of high-precision NEMS components. The key challenge in NEMS is therefore the development of new methods for routine and reproducible nanofabrication. Two complementary types of method for NEMS fabrication are available: 'top-down' and 'bottom-up'. The top-down approach uses traditional lithography technologies, whereas bottom-up techniques include molecular self-organization, self-assembly and nanodeposition. The NT2008 conference, held at Ishikawa High-Tech Conference Center, Ishikawa, Japan, between 23-25 October 2008, focused on novel NEMS fabricated from new materials and on process technologies. The topics included compound semiconductors, small mechanical structures, nanostructures for micro-fluid and bio-sensors, bio-hybrid micro-machines, as well as their design and simulation. This focus issue compiles seven articles selected from 13 submitted manuscripts. The articles by Prinz et al and Kehrbusch et al introduce the frontiers of the top-down production of various operational NEMS devices, and Kometani et al present an example of the bottom-up approach, namely ion-beam induced deposition of MEMS and NEMS. The remaining articles report novel technologies for biological sensors. Taira et al have used manganese nanoparticles

12 -μ m -Pitch Electromechanical Resonator for Thermal Sensing

NASA Astrophysics Data System (ADS)

Laurent, Ludovic; Yon, Jean-Jacques; Moulet, Jean-Sébastien; Roukes, Michael; Duraffourg, Laurent

2018-02-01

We provide here a demonstration of 12 -μ m -pitch nanoelectromechanical resonant infrared sensors with fully integrated capacitive transduction. A low-temperature fabrication process is used to manufacture torsional resonator arrays. An H -shaped pixel with 9 -μ m -long nanorods and (250 ×30 )-nm2 cross section is designed to provide high thermal response whose experimental measurements reach up to 1024 Hz /nW . A mechanical dynamic range of over 113 dB is obtained, which leads to an Allan deviation of σA=3 ×10-7 at room temperature and 50-Hz noise bandwidth (σA=1.5 ×10-7 over 10 Hz). These features allow us to reach a sensitivity of (8 - 12 )-μ m radiation of 27 pW / √{Hz } leading to a noise-equivalent temperature difference (NETD) of 2 K for a 50-Hz noise bandwidth (NETD =1.5 K at 10 Hz). We demonstrate that the resolution is no more set by the phonon noise but by the anomalous phase noise already encountered in flexural nanoresonators. By both improving the temperature coefficient of frequency of a factor 10 and using a readout electronics at the pixel level, these resonators will lead to a breakthrough for uncooled infrared detectors. We expect that the NETD will rapidly drop to 180 mK with electronics close to the pixel. As a result of the features of our torsional resonators, an alternative readout scheme of pixels is suggested.

The role of Euler buckling instability in the fabrication of nanoelectromechanical systems on the basis of GaAs/AlGaAs heterostructures

NASA Astrophysics Data System (ADS)

Shevyrin, A. A.; Pogosov, A. G.; Budantsev, M. V.; Bakarov, A. K.; Toropov, A. I.; Ishutkin, S. V.; Shesterikov, E. V.; Kozhukhov, A. S.; Kosolobov, S. S.; Gavrilova, T. A.

2012-12-01

Mechanical stresses are investigated in suspended nanowires made on the basis of GaAs/AlGaAs heterostructures. Though there are no intentionally introduced stressor layers in the heterostructure, the nanowires are subject to Euler buckling instability. In the wide nanowires, the out-of-plane buckling is observed at length significantly smaller (3 times) than the theoretically estimated critical value, while in the narrow nanowires, the experimentally measured critical length of the in-plane buckling coincides with the theoretical estimation. The possible reasons for the obtained discrepancy are considered. The observed peculiarities should be taken into account in the fabrication of nanomechanical and nanoelectromechanical systems.

Gold Nanorod Rotary Motors Driven by Resonant Light Scattering.

PubMed

Shao, Lei; Yang, Zhong-Jian; Andrén, Daniel; Johansson, Peter; Käll, Mikael

2015-12-22

Efficient and robust artificial nanomotors could provide a variety of exciting possibilities for applications in physics, biology and chemistry, including nanoelectromechanical systems, biochemical sensing, and drug delivery. However, the application of current man-made nanomotors is limited by their sophisticated fabrication techniques, low mechanical output power and severe environmental requirements, making their performance far below that of natural biomotors. Here we show that single-crystal gold nanorods can be rotated extremely fast in aqueous solutions through optical torques dominated by plasmonic resonant scattering of circularly polarized laser light with power as low as a few mW. The nanorods are trapped in 2D against a glass surface, and their rotational dynamics is highly dependent on their surface plasmon resonance properties. They can be kept continuously rotating for hours with limited photothermal side effects and they can be applied for detection of molecular binding with high sensitivity. Because of their biocompatibility, mechanical and thermal stability, and record rotation speeds reaching up to 42 kHz (2.5 million revolutions per minute), these rotary nanomotors could advance technologies to meet a wide range of future nanomechanical and biomedical needs in fields such as nanorobotics, nanosurgery, DNA manipulation and nano/microfluidic flow control.

In-situ comprehensive calibration of a tri-port nano-electro-mechanical device.

PubMed

Collin, E; Defoort, M; Lulla, K; Moutonet, T; Heron, J-S; Bourgeois, O; Bunkov, Yu M; Godfrin, H

2012-04-01

We report on experiments performed in vacuum and at cryogenic temperatures on a tri-port nano-electro-mechanical (NEMS) device. One port is a very nonlinear capacitive actuation, while the two others implement the magnetomotive scheme with a linear input force port and a (quasi-linear) output velocity port. We present an experimental method enabling a full characterization of the nanomechanical device harmonic response: the nonlinear capacitance function C(x) is derived, and the normal parameters k and m (spring constant and mass) of the mode under study are measured through a careful definition of the motion (in meters) and of the applied forces (in Newtons). These results are obtained with a series of purely electric measurements performed without disconnecting/reconnecting the device, and rely only on known dc properties of the circuit, making use of a thermometric property of the oscillator itself: we use the Young modulus of the coating metal as a thermometer, and the resistivity for Joule heating. The setup requires only three connecting lines without any particular matching, enabling the preservation of a high impedance NEMS environment even at MHz frequencies. The experimental data are fit to a detailed electrical and thermal model of the NEMS device, demonstrating a complete understanding of its dynamics. These methods are quite general and can be adapted (as a whole, or in parts) to a large variety of electromechanical devices. © 2012 American Institute of Physics

Acoustic superlens using Helmholtz-resonator-based metamaterials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Xishan; Yin, Jing; Yu, Gaokun, E-mail: gkyu@ouc.edu.cn

2015-11-09

Acoustic superlens provides a way to overcome the diffraction limit with respect to the wavelength of the bulk wave in air. However, the operating frequency range of subwavelength imaging is quite narrow. Here, an acoustic superlens is designed using Helmholtz-resonator-based metamaterials to broaden the bandwidth of super-resolution. An experiment is carried out to verify subwavelength imaging of double slits, the imaging of which can be well resolved in the frequency range from 570 to 650 Hz. Different from previous works based on the Fabry-Pérot resonance, the corresponding mechanism of subwavelength imaging is the Fano resonance, and the strong coupling between themore » neighbouring Helmholtz resonators separated at the subwavelength interval leads to the enhanced sound transmission over a relatively wide frequency range.« less

Sensitivity improvements of a resonance-based tactile sensor.

PubMed

Murayama, Yoshinobu; Lindahl, Olof A

2017-02-01

Resonance-based contact-impedance measurement refers to the application of resonance sensors based on the measurement of the changes in the resonance curve of an ultrasonic resonator in contact with a surface. The advantage of the resonance sensor is that it is very sensitive to small changes in the contact impedance. A sensitive micro tactile sensor (MTS) was developed, which measured the elasticity of soft living tissues at the single-cell level. In the present paper, we studied the method of improving the touch and stiffness sensitivity of the MTS. First, the dependence of touch sensitivity in relation to the resonator length was studied by calculating the sensitivity coefficient at each length ranging from 9 to 40 mm. The highest touch sensitivity was obtained with a 30-mm-long glass needle driven at a resonance frequency of 100 kHz. Next, the numerical calculation of contact impedance showed that the highest stiffness sensitivity was achieved when the driving frequency was 100 kHz and the contact-tip diameter of the MTS was 10 μm. The theoretical model was then confirmed experimentally using a phase-locked-loop-based digital feedback oscillation circuit. It was found that the developed MTS, whose resonant frequency was 97.030 kHz, performed with the highest sensitivity of 53.2 × 10 6  Hz/N at the driving frequency of 97.986 kHz, i.e. the highest sensitivity was achieved at 956 Hz above the resonant frequency.

GaAs-based micro/nanomechanical resonators

NASA Astrophysics Data System (ADS)

Yamaguchi, Hiroshi

2017-10-01

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.

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

PubMed

Tang, Yue; Zhang, Zhidong; Wang, Ruibing; Hai, Zhenyin; Xue, Chenyang; Zhang, Wendong; Yan, Shubin

2017-04-06

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.

Nanoscale devices based on plasmonic coaxial waveguide resonators

NASA Astrophysics Data System (ADS)

Mahigir, A.; Dastmalchi, P.; Shin, W.; Fan, S.; Veronis, G.

2015-02-01

Waveguide-resonator systems are particularly useful for the development of several integrated photonic devices, such as tunable filters, optical switches, channel drop filters, reflectors, and impedance matching elements. In this paper, we introduce nanoscale devices based on plasmonic coaxial waveguide resonators. In particular, we investigate threedimensional nanostructures consisting of plasmonic coaxial stub resonators side-coupled to a plasmonic coaxial waveguide. We use coaxial waveguides with square cross sections, which can be fabricated using lithography-based techniques. The waveguides are placed on top of a silicon substrate, and the space between inner and outer coaxial metals is filled with silica. We use silver as the metal. We investigate structures consisting of a single plasmonic coaxial resonator, which is terminated either in a short or an open circuit, side-coupled to a coaxial waveguide. We show that the incident waveguide mode is almost completely reflected on resonance, while far from the resonance the waveguide mode is almost completely transmitted. We also show that the properties of the waveguide systems can be accurately described using a single-mode scattering matrix theory. The transmission and reflection coefficients at waveguide junctions are either calculated using the concept of the characteristic impedance or are directly numerically extracted using full-wave three-dimensional finite-difference frequency-domain simulations.

Coupled resonator optical waveguides based on silicon-on-insulator photonic wires

NASA Astrophysics Data System (ADS)

Xia, Fengnian; Sekaric, Lidija; O'Boyle, Martin; Vlasov, Yurii

2006-07-01

Coupled resonator optical waveguides (CROWs) comprised of up to 16 racetrack resonators based on silicon-on-insulator (SOI) photonic wires were fabricated and characterized. The optical properties of the CROWs were simulated using measured single resonator parameters based on a matrix approach. The group delay property of CROWs was also analyzed. The SOI based CROWs consisting of multiple resonators have extremely small footprints and can find applications in optical filtering, dispersion compensation, and optical buffering. Moreover, such CROW structure is a promising candidate for exploration of low light level nonlinear optics due to its resonant nature and compact mode size (˜0.1μm2) in photonic wire.

Ring resonator based narrow-linewidth semiconductor lasers

NASA Technical Reports Server (NTRS)

Ksendzov, Alexander (Inventor)

2005-01-01

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

Designing a Double-Pole Nanoscale Relay Based on a Carbon Nanotube: A Theoretical Study

NASA Astrophysics Data System (ADS)

Mu, Weihua; Ou-Yang, Zhong-can; Dresselhaus, Mildred S.

2017-08-01

We theoretically investigate a novel and powerful double-pole nanoscale relay based on a carbon nanotube, which is one of the nanoelectromechanical switches being able to work under the strong nuclear radiation, and analyze the physical mechanism of the operating stages in the operation, including "pull in," "connection," and "pull back," as well as the key factors influencing the efficiency of the devices. We explicitly provide the analytical expression of the two important operation voltages, Vpull in and Vpull back , therefore clearly showing the dependence of the material properties and geometry of the present devices by the analytical method from basic physics, avoiding complex numerical calculations. Our method is easy to use in preparing the design guide for fabricating the present device and other nanoelectromechanical devices.

Optical modulator based on silicon nanowires racetrack resonator

NASA Astrophysics Data System (ADS)

Sherif, S. M.; Shahada, L.; Swillam, M.

2018-02-01

An optical modulator based on the racetrack resonator configuration is introduced. The structure of the resonator modulator is built from silicon nanowires on silica. The cladding and voids between the silicon nanowires are filled with an electro-optic polymer. The proposed modulator is fully CMOS compatible. When the resonance is tuned to the 1.55μm wavelength, it experiences a wavelength shift upon voltage application, which is measured at the output as a change in the power level.

A time domain based method for the accurate measurement of Q-factor and resonance frequency of microwave resonators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gyüre, B.; Márkus, B. G.; Bernáth, B.

2015-09-15

We present a novel method to determine the resonant frequency and quality factor of microwave resonators which is faster, more stable, and conceptually simpler than the yet existing techniques. The microwave resonator is pumped with the microwave radiation at a frequency away from its resonance. It then emits an exponentially decaying radiation at its eigen-frequency when the excitation is rapidly switched off. The emitted microwave signal is down-converted with a microwave mixer, digitized, and its Fourier transformation (FT) directly yields the resonance curve in a single shot. Being a FT based method, this technique possesses the Fellgett (multiplex) and Connesmore » (accuracy) advantages and it conceptually mimics that of pulsed nuclear magnetic resonance. We also establish a novel benchmark to compare accuracy of the different approaches of microwave resonator measurements. This shows that the present method has similar accuracy to the existing ones, which are based on sweeping or modulating the frequency of the microwave radiation.« less

Chemical Sensors Based on Optical Ring Resonators

NASA Technical Reports Server (NTRS)

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

2005-01-01

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

Development of an ICT-Based Air Column Resonance Learning Media

NASA Astrophysics Data System (ADS)

Purjiyanta, Eka; Handayani, Langlang; Marwoto, Putut

2016-08-01

Commonly, the sound source used in the air column resonance experiment is the tuning fork having disadvantage of unoptimal resonance results due to the sound produced which is getting weaker. In this study we made tones with varying frequency using the Audacity software which were, then, stored in a mobile phone as a source of sound. One advantage of this sound source is the stability of the resulting sound enabling it to produce the same powerful sound. The movement of water in a glass tube mounted on the tool resonance and the tone sound that comes out from the mobile phone were recorded by using a video camera. Sound resonances recorded were first, second, and third resonance, for each tone frequency mentioned. The resulting sound stays longer, so it can be used for the first, second, third and next resonance experiments. This study aimed to (1) explain how to create tones that can substitute tuning forks sound used in air column resonance experiments, (2) illustrate the sound wave that occurred in the first, second, and third resonance in the experiment, and (3) determine the speed of sound in the air. This study used an experimental method. It was concluded that; (1) substitute tones of a tuning fork sound can be made by using the Audacity software; (2) the form of sound waves that occured in the first, second, and third resonance in the air column resonance can be drawn based on the results of video recording of the air column resonance; and (3) based on the experiment result, the speed of sound in the air is 346.5 m/s, while based on the chart analysis with logger pro software, the speed of sound in the air is 343.9 ± 0.3171 m/s.

Single-protein nanomechanical mass spectrometry in real time

PubMed Central

Hanay, M.S.; Kelber, S.; Naik, A.K.; Chi, D.; Hentz, S.; Bullard, E.C.; Colinet, E.; Duraffourg, L.; Roukes, M.L.

2012-01-01

Nanoelectromechanical systems (NEMS) resonators can detect mass with exceptional sensitivity. Previously, mass spectra from several hundred adsorption events were assembled in NEMS-based mass spectrometry using statistical analysis. Here, we report the first realization of single-molecule NEMS-based mass spectrometry in real time. As each molecule in the sample adsorbs upon the NEMS resonator, its mass and the position-of-adsorption are determined by continuously tracking two driven vibrational modes of the device. We demonstrate the potential of multimode NEMS-based mass spectrometry by analyzing IgM antibody complexes in real-time. NEMS-MS is a unique and promising new form of mass spectrometry: it can resolve neutral species, provides resolving power that increases markedly for very large masses, and allows acquisition of spectra, molecule-by-molecule, in real-time. PMID:22922541

Investigations on an electroactive polymer based tunable Helmholtz resonator

NASA Astrophysics Data System (ADS)

Abbad, A.; Rabenorosoa, K.; Ouisse, M.; Atalla, N.

2017-04-01

A Helmholtz resonator is a passive acoustic resonator classically used to control a single frequency resulting from the cavity volume and the resonator neck size. The aim of the proposed study is to present a new concept and strategy allowing real-time tunability of the Helmholtz resonator in order to enhance acoustic absorption performances at low frequencies (< 500 Hz). The proposed concept consists in replacing the resonator rigid front plate by an electroactive polymer (EAP) membrane. The first proposed strategy consists on a change in the mechanical properties of the membrane resulting from the applied electric field. This induces a resonance frequency shift. A second strategy is based on a well-located spring, which could direct the membrane deformation following the axis of the resonator to obtain a cavity volume variation. Both strategies allow variation of the resonance frequency of the device. Experimental measurements are performed to determine the potential of this concept for improvement of low-frequency performances of the acoustic devices.

Parametric nanomechanical amplification at very high frequency.

PubMed

Karabalin, R B; Feng, X L; Roukes, M L

2009-09-01

Parametric resonance and amplification are important in both fundamental physics and technological applications. Here we report very high frequency (VHF) parametric resonators and mechanical-domain amplifiers based on nanoelectromechanical systems (NEMS). Compound mechanical nanostructures patterned by multilayer, top-down nanofabrication are read out by a novel scheme that parametrically modulates longitudinal stress in doubly clamped beam NEMS resonators. Parametric pumping and signal amplification are demonstrated for VHF resonators up to approximately 130 MHz and provide useful enhancement of both resonance signal amplitude and quality factor. We find that Joule heating and reduced thermal conductance in these nanostructures ultimately impose an upper limit to device performance. We develop a theoretical model to account for both the parametric response and nonequilibrium thermal transport in these composite nanostructures. The results closely conform to our experimental observations, elucidate the frequency and threshold-voltage scaling in parametric VHF NEMS resonators and sensors, and establish the ultimate sensitivity limits of this approach.

Protein Sensors Based on Optical Ring Resonators

NASA Technical Reports Server (NTRS)

Lin, Ying; Ksendzov, Alexander

2006-01-01

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

Wireless power transfer based on dielectric resonators with colossal permittivity

NASA Astrophysics Data System (ADS)

Song, Mingzhao; Belov, Pavel; Kapitanova, Polina

2016-11-01

Magnetic resonant wireless power transfer system based on dielectric disk resonators made of colossal permittivity (ɛ = 1000) and low loss (tan δ = 2.5 × 10-4) microwave ceramic is experimentally investigated. The system operates at the magnetic dipole mode excited in the resonators providing maximal power transfer efficiency of 90% at the frequency 232 MHz. By applying an impedance matching technique, the efficiency of 50% is achieved within the separation between the resonators d = 16 cm (3.8 radii of the resonator). The separation, misalignment and rotation dependencies of wireless power transfer efficiency are experimentally studied.

Plasmonic hydrogen sensor based on integrated microring resonator

NASA Astrophysics Data System (ADS)

Yi, Ya Sha; Wu, Da Chuan

2017-12-01

We have proposed and demonstrated numerically an ultrasmall and highly sensitive plasmonic hydrogen sensor based on an integrated microring resonator, with a footprint size as small as 4×4 μm2. With a palladium (Pd) or platinum (Pt) hydrogen-sensitive layer coated on the inner surface of the microring resonator and the excitation of surface plasmon modes at the interface from the microring resonator waveguide, the device is highly sensitive to low hydrogen concentration variation, and the sensitivity is at least one order of magnitude larger than that of the optical fiber-based hydrogen sensor. We have also investigated the tradeoff between the portion coverage of the Pd/Pt layer and the sensitivity, as well as the width of the hydrogen-sensitive layer. This ultrasmall plasmonic hydrogen sensor holds promise for the realization of a highly compact sensor with integration capability for applications in hydrogen fuel economy.

Ultrasensitive displacement sensor based on tunable horn-shaped resonators

NASA Astrophysics Data System (ADS)

Tian, Ying; Wu, Jiong; Yu, Le; Yang, Helin; Huang, Xiaojun

2018-04-01

In this paper, we proposed a novel double-deck displacement sensor with a high linearity based on tunable horn-shaped resonators. The designed sensor included two substrate layers etched with copper metallization in various shapes. When the upper trip-type resonator layer has a relative displacement to the bottom horn-shaped resonator layer, the resonance frequency of the sensor is redshift. High sensitivity of the sensor is around 207.2 MHz mm-1 with 4 mm linear dynamic range. We fabricate the sample of the proposed displacement sensor, in addition the simulated results are verified by experiment. The proposed displacement sensor is appropriate for using MEMS technology in further miniaturization.

Resonant microsphere gyroscope based on a double Faraday rotator system.

PubMed

Xie, Chengfeng; Tang, Jun; Cui, Danfeng; Wu, Dajin; Zhang, Chengfei; Li, Chunming; Zhen, Yongqiu; Xue, Chenyang; Liu, Jun

2016-10-15

The resonant microsphere gyroscope is proposed based on a double Faraday rotator system for the resonant microsphere gyroscope (RMSG) that is characterized by low insertion losses and does not destroy the reciprocity of the gyroscope system. Use of the echo suppression structure and the orthogonal polarization method can effectively inhibit both the backscattering noise and the polarization error, and reduce them below the system sensitivity limit. The resonance asymmetry rate dropped from 34.2% to 2.9% after optimization of the backscattering noise and the polarization noise, which greatly improved the bias stability and the scale factor linearity of the proposed system. Additionally, based on the optimum parameters for the double Faraday rotator system, a bias stability of 0.04°/s has been established for an integration time of 10 s in 1000 s in a resonator microsphere gyroscope using a microsphere resonator with a diameter of 1 mm and a Q of 7.2×10⁶.

Design and Analyses of a MEMS Based Resonant Magnetometer

PubMed Central

Ren, Dahai; Wu, Lingqi; Yan, Meizhi; Cui, Mingyang; You, Zheng; Hu, Muzhi

2009-01-01

A novel design of a MEMS torsional resonant magnetometer based on Lorentz force is presented and fabricated. The magnetometer consists of a silicon resonator, torsional beam, excitation coil, capacitance plates and glass substrate. Working in a resonant condition, the sensor’s vibration amplitude is converted into the sensing capacitance change, which reflects the outside magnetic flux-density. Based on the simulation, the key structure parameters are optimized and the air damping effect is estimated. The test results of the prototype are in accordance with the simulation results of the designed model. The resolution of the magnetometer can reach 30 nT. The test results indicate its sensitivity of more than 400 mV/μT when operating in a 10 Pa vacuum environment. PMID:22399981

Electrically tunable metasurface based on Mie-type dielectric resonators.

PubMed

Su, Zhaoxian; Zhao, Qian; Song, Kun; Zhao, Xiaopeng; Yin, Jianbo

2017-02-21

In this paper, we have designed a metasurface based on electrically tunable Mie-type resonators and theoretically demonstrated its tunable response to electromagnetic waves with varying frequency. The metasurface consists of disk-like ferroelectric resonators arrayed on a metal film and the upper surface of resonators is covered by ion gel film which is transparent for incident electromagnetic wave. Using the metal film and ion gel film as electrodes, the permittivity of the resonators can be adjusted by an external electric field and, as a result, the reflection phase of the resonators can be dynamically adjusted in a relatively wide range. By programmable controlling the electric field strength applied on resonators of metasurface, a 2π phase ramp can be realized and, thereby, the arbitrary reflection behavior of incident waves with varied frequency is obtained. Because of the tunability, this metasurface can also be used to design adaptive metasurface lens and carpet cloak.

Electrically tunable metasurface based on Mie-type dielectric resonators

PubMed Central

Su, Zhaoxian; Zhao, Qian; Song, Kun; Zhao, Xiaopeng; Yin, Jianbo

2017-01-01

In this paper, we have designed a metasurface based on electrically tunable Mie-type resonators and theoretically demonstrated its tunable response to electromagnetic waves with varying frequency. The metasurface consists of disk-like ferroelectric resonators arrayed on a metal film and the upper surface of resonators is covered by ion gel film which is transparent for incident electromagnetic wave. Using the metal film and ion gel film as electrodes, the permittivity of the resonators can be adjusted by an external electric field and, as a result, the reflection phase of the resonators can be dynamically adjusted in a relatively wide range. By programmable controlling the electric field strength applied on resonators of metasurface, a 2π phase ramp can be realized and, thereby, the arbitrary reflection behavior of incident waves with varied frequency is obtained. Because of the tunability, this metasurface can also be used to design adaptive metasurface lens and carpet cloak. PMID:28220861

Electrically tunable metasurface based on Mie-type dielectric resonators

NASA Astrophysics Data System (ADS)

Su, Zhaoxian; Zhao, Qian; Song, Kun; Zhao, Xiaopeng; Yin, Jianbo

2017-02-01

In this paper, we have designed a metasurface based on electrically tunable Mie-type resonators and theoretically demonstrated its tunable response to electromagnetic waves with varying frequency. The metasurface consists of disk-like ferroelectric resonators arrayed on a metal film and the upper surface of resonators is covered by ion gel film which is transparent for incident electromagnetic wave. Using the metal film and ion gel film as electrodes, the permittivity of the resonators can be adjusted by an external electric field and, as a result, the reflection phase of the resonators can be dynamically adjusted in a relatively wide range. By programmable controlling the electric field strength applied on resonators of metasurface, a 2π phase ramp can be realized and, thereby, the arbitrary reflection behavior of incident waves with varied frequency is obtained. Because of the tunability, this metasurface can also be used to design adaptive metasurface lens and carpet cloak.

Dual-band plasmonic resonator based on Jerusalem cross-shaped nanoapertures

NASA Astrophysics Data System (ADS)

Cetin, Arif E.; Kaya, Sabri; Mertiri, Alket; Aslan, Ekin; Erramilli, Shyamsunder; Altug, Hatice; Turkmen, Mustafa

2015-06-01

In this paper, we both experimentally and numerically introduce a dual-resonant metamaterial based on subwavelength Jerusalem cross-shaped apertures. We numerically investigate the physical origin of the dual-resonant behavior, originating from the constituting aperture elements, through finite difference time domain calculations. Our numerical calculations show that at the dual-resonances, the aperture system supports large and easily accessible local electromagnetic fields. In order to experimentally realize the aperture system, we utilize a high-precision and lift-off free fabrication method based on electron-beam lithography. We also introduce a fine-tuning mechanism for controlling the dual-resonant spectral response through geometrical device parameters. Finally, we show the aperture system's highly advantageous far- and near-field characteristics through numerical calculations on refractive index sensitivity. The quantitative analyses on the availability of the local fields supported by the aperture system are employed to explain the grounds behind the sensitivity of each spectral feature within the dual-resonant behavior. Possessing dual-resonances with large and accessible electromagnetic fields, Jerusalem cross-shaped apertures can be highly advantageous for wide range of applications demanding multiple spectral features with strong nearfield characteristics.

A capacitive ultrasonic transducer based on parametric resonance.

PubMed

Surappa, Sushruta; Satir, Sarp; Levent Degertekin, F

2017-07-24

A capacitive ultrasonic transducer based on a parametric resonator structure is described and experimentally demonstrated. The transducer structure, which we call capacitive parametric ultrasonic transducer (CPUT), uses a parallel plate capacitor with a movable membrane as part of a degenerate parametric series RLC resonator circuit with a resonance frequency of f o . When the capacitor plate is driven with an incident harmonic ultrasonic wave at the pump frequency of 2f o with sufficient amplitude, the RLC circuit becomes unstable and ultrasonic energy can be efficiently converted to an electrical signal at f o frequency in the RLC circuit. An important characteristic of the CPUT is that unlike other electrostatic transducers, it does not require DC bias or permanent charging to be used as a receiver. We describe the operation of the CPUT using an analytical model and numerical simulations, which shows drive amplitude dependent operation regimes including parametric resonance when a certain threshold is exceeded. We verify these predictions by experiments with a micromachined membrane based capacitor structure in immersion where ultrasonic waves incident at 4.28 MHz parametrically drive a signal with significant amplitude in the 2.14 MHz RLC circuit. With its unique features, the CPUT can be particularly advantageous for applications such as wireless power transfer for biomedical implants and acoustic sensing.

Towards Automated Structure-Based NMR Resonance Assignment

NASA Astrophysics Data System (ADS)

Jang, Richard; Gao, Xin; Li, Ming

We propose a general framework for solving the structure-based NMR backbone resonance assignment problem. The core is a novel 0-1 integer programming model that can start from a complete or partial assignment, generate multiple assignments, and model not only the assignment of spins to residues, but also pairwise dependencies consisting of pairs of spins to pairs of residues. It is still a challenge for automated resonance assignment systems to perform the assignment directly from spectra without any manual intervention. To test the feasibility of this for structure-based assignment, we integrated our system with our automated peak picking and sequence-based resonance assignment system to obtain an assignment for the protein TM1112 with 91% recall and 99% precision without manual intervention. Since using a known structure has the potential to allow one to use only N-labeled NMR data and avoid the added expense of using C-labeled data, we work towards the goal of automated structure-based assignment using only such labeled data. Our system reduced the assignment error of Xiong-Pandurangan-Bailey-Kellogg's contact replacement (CR) method, which to our knowledge is the most error-tolerant method for this problem, by 5 folds on average. By using an iterative algorithm, our system has the added capability of using the NOESY data to correct assignment errors due to errors in predicting the amino acid and secondary structure type of each spin system. On a publicly available data set for Ubiquitin, where the type prediction accuracy is 83%, we achieved 91% assignment accuracy, compared to the 59% accuracy that was obtained without correcting for typing errors.

Nanoelectromechanical Chip (NELMEC) Combination of Nanoelectronics and Microfluidics to Diagnose Epithelial and Mesenchymal Circulating Tumor Cells from Leukocytes.

PubMed

Hosseini, Seied Ali; Abdolahad, Mohammad; Zanganeh, Somayeh; Dahmardeh, Mahyar; Gharooni, Milad; Abiri, Hamed; Alikhani, Alireza; Mohajerzadeh, Shams; Mashinchian, Omid

2016-02-17

An integrated nano-electromechanical chip (NELMEC) has been developed for the label-free distinguishing of both epithelial and mesenchymal circulating tumor cells (ECTCs and MCTCs, respectively) from white blood cells (WBCs). This nanoelectronic microfluidic chip fabricated by silicon micromachining can trap large single cells (>12 µm) at the opening of the analysis microchannel arrays. The nature of the captured cells is detected using silicon nanograss (SiNG) electrodes patterned at the entrance of the channels. There is an observable difference between the membrane capacitance of the ECTCs and MCTCs and that of WBCs (measured using SiNG electrodes), which is the key indication for our diagnosis. The NELMEC chip not only solves the problem of the size overlap between CTCs and WBCs but also detects MCTCs without the need for any markers or tagging processes, which has been an important problem in previously reported CTC detection systems. The great conductivity of the gold-coated SiNG nanocontacts as well as their safe penetration into the membrane of captured cells, facilitate a precise and direct signal extraction to distinguish the type of captured cell. The results achieved from epithelial (MCF-7) and mesenchymal (MDA-MB231) breast cancer cells circulated in unprocessed blood suggest the significant applications for these diagnostic abilities of NELMEC. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Strain gauge using Si-based optical microring resonator.

PubMed

Lei, Longhai; Tang, Jun; Zhang, Tianen; Guo, Hao; Li, Yanna; Xie, Chengfeng; Shang, Chenglong; Bi, Yu; Zhang, Wendong; Xue, Chenyang; Liu, Jun

2014-12-20

This paper presents a strain gauge using the mechanical-optical coupling method. The Si-based optical microring resonator was employed as the sensing element, which was embedded on the microcantilevers. The experimental results show that applying external strain triggers a clear redshift of the output resonant spectrum of the structure. The sensitivity of 93.72  pm/MPa was achieved, which also was verified using theoretical simulations. This paper provides what we believe is a new method to develop micro-opto-electromechanical system (MOEMS) sensors.

Modeling and analysis of a resonant nanosystem

NASA Astrophysics Data System (ADS)

Calvert, Scott L.

The majority of investigations into nanoelectromechanical resonators focus on a single area of the resonator's function. This focus varies from the development of a model for a beam's vibration, to the modeling of electrostatic forces, to a qualitative explanation of experimentally-obtained currents. Despite these efforts, there remains a gap between these works, and the level of sophistication needed to truly design nanoresonant systems for efficient commercial use. Towards this end, a comprehensive system model for both a nanobeam resonator and its related experimental setup is proposed. Furthermore, a simulation arrangement is suggested as a method for facilitating the study of the system-level behavior of these devices in a variety of cases that could not be easily obtained experimentally or analytically. The dynamics driving the nanoresonator's motion, as well as the electrical interactions influencing the forcing and output of the system, are modeled, experimentally validated, and studied. The model seeks to develop both a simple circuit representation of the nanoresonator, and to create a mathematical system that can be used to predict and interpret the observed behavior. Due to the assumptions used to simplify the model to a point of reasonable comprehension, the model is most accurate for small beam deflections near the first eigenmode of the beam. The process and results of an experimental investigation are documented, and compared with a circuit simulation modeling the full test system. The comparison qualitatively proves the functionality of the model, while a numerical analysis serves to validate the functionality and setup of the circuit simulation. The use of the simulation enables a much broader investigation of both the electrical behavior and the physical device's dynamics. It is used to complement an assessment of the tuning behavior of the system's linear natural frequency by demonstrating the tuning behavior of the full nonlinear response. The

Microwave Photonics Systems Based on Whispering-gallery-mode Resonators

PubMed Central

Coillet, Aurélien; Henriet, Rémi; Phan Huy, Kien; Jacquot, Maxime; Furfaro, Luca; Balakireva, Irina; Larger, Laurent; Chembo, Yanne K.

2013-01-01

Microwave photonics systems rely fundamentally on the interaction between microwave and optical signals. These systems are extremely promising for various areas of technology and applied science, such as aerospace and communication engineering, sensing, metrology, nonlinear photonics, and quantum optics. In this article, we present the principal techniques used in our lab to build microwave photonics systems based on ultra-high Q whispering gallery mode resonators. First detailed in this article is the protocol for resonator polishing, which is based on a grind-and-polish technique close to the ones used to polish optical components such as lenses or telescope mirrors. Then, a white light interferometric profilometer measures surface roughness, which is a key parameter to characterize the quality of the polishing. In order to launch light in the resonator, a tapered silica fiber with diameter in the micrometer range is used. To reach such small diameters, we adopt the "flame-brushing" technique, using simultaneously computer-controlled motors to pull the fiber apart, and a blowtorch to heat the fiber area to be tapered. The resonator and the tapered fiber are later approached to one another to visualize the resonance signal of the whispering gallery modes using a wavelength-scanning laser. By increasing the optical power in the resonator, nonlinear phenomena are triggered until the formation of a Kerr optical frequency comb is observed with a spectrum made of equidistant spectral lines. These Kerr comb spectra have exceptional characteristics that are suitable for several applications in science and technology. We consider the application related to ultra-stable microwave frequency synthesis and demonstrate the generation of a Kerr comb with GHz intermodal frequency. PMID:23963358

Microwave photonics systems based on whispering-gallery-mode resonators.

PubMed

Coillet, Aurélien; Henriet, Rémi; Phan Huy, Kien; Jacquot, Maxime; Furfaro, Luca; Balakireva, Irina; Larger, Laurent; Chembo, Yanne K

2013-08-05

Microwave photonics systems rely fundamentally on the interaction between microwave and optical signals. These systems are extremely promising for various areas of technology and applied science, such as aerospace and communication engineering, sensing, metrology, nonlinear photonics, and quantum optics. In this article, we present the principal techniques used in our lab to build microwave photonics systems based on ultra-high Q whispering gallery mode resonators. First detailed in this article is the protocol for resonator polishing, which is based on a grind-and-polish technique close to the ones used to polish optical components such as lenses or telescope mirrors. Then, a white light interferometric profilometer measures surface roughness, which is a key parameter to characterize the quality of the polishing. In order to launch light in the resonator, a tapered silica fiber with diameter in the micrometer range is used. To reach such small diameters, we adopt the "flame-brushing" technique, using simultaneously computer-controlled motors to pull the fiber apart, and a blowtorch to heat the fiber area to be tapered. The resonator and the tapered fiber are later approached to one another to visualize the resonance signal of the whispering gallery modes using a wavelength-scanning laser. By increasing the optical power in the resonator, nonlinear phenomena are triggered until the formation of a Kerr optical frequency comb is observed with a spectrum made of equidistant spectral lines. These Kerr comb spectra have exceptional characteristics that are suitable for several applications in science and technology. We consider the application related to ultra-stable microwave frequency synthesis and demonstrate the generation of a Kerr comb with GHz intermodal frequency.

Plasmon resonance hybridization in self-assembled copper nanoparticle clusters: efficient and precise localization of surface plasmon resonance (LSPR) sensing based on Fano resonances.

PubMed

Ahmadivand, Arash; Pala, Nezih

2015-01-01

In this work, we have investigated the hybridization of plasmon resonance modes in completely copper (Cu)-based subwavelength nanoparticle clusters from simple symmetric dimers to complex asymmetric self-assembled structures. The quality of apparent bonding and antibonding plasmon resonance modes for all of the clusters has been studied, and we examined the spectral response of each one of the proposed configurations numerically using the finite-difference time domain (FDTD) method. The effect of the geometric sizes of nanoparticles used and substrate refractive index on the cross-sectional profiles of each of the studied structures has been calculated and drawn. We proved that Fano-like resonance can be formed in Cu-based heptamer clusters as in analogous noble metallic particles (e.g., Au and Ag) by determining the coupling strength and interference between sub-radiant and super-radiant resonance modes. Employing certain Cu nanodiscs in designing an octamer structure, we measured the quality of the Fano dip formation along the scattering diagram. Accurate tuning of the geometric sizes for the Cu-based octamer yields an opportunity to observe isotropic, deep, and narrow Fano minima along the scattering profile that are in comparable condition with the response of other plasmonic metallic substances. Immersing investigated final Cu-based octamer in various liquids with different refractive indices, we determined the sensing accuracy of the cluster based on the performance of the Fano dip. Plotting a linear diagram of plasmon energy differences over the refractive index variations as a figure of merit (FoM), which we have quantified as 13.25. With this method, the precision of the completely Cu-based octamer is verified numerically using the FDTD tool. This study paves the way toward the use of Cu as an efficient, low-cost, and complementary metal-oxide semiconductor (CMOS)-compatible plasmonic material with optical properties that are similar to analogous plasmonic

Multicoil resonance-based parallel array for smart wireless power delivery.

PubMed

Mirbozorgi, S A; Sawan, M; Gosselin, B

2013-01-01

This paper presents a novel resonance-based multicoil structure as a smart power surface to wirelessly power up apparatus like mobile, animal headstage, implanted devices, etc. The proposed powering system is based on a 4-coil resonance-based inductive link, the resonance coil of which is formed by an array of several paralleled coils as a smart power transmitter. The power transmitter employs simple circuit connections and includes only one power driver circuit per multicoil resonance-based array, which enables higher power transfer efficiency and power delivery to the load. The power transmitted by the driver circuit is proportional to the load seen by the individual coil in the array. Thus, the transmitted power scales with respect to the load of the electric/electronic system to power up, and does not divide equally over every parallel coils that form the array. Instead, only the loaded coils of the parallel array transmit significant part of total transmitted power to the receiver. Such adaptive behavior enables superior power, size and cost efficiency then other solutions since it does not need to use complex detection circuitry to find the location of the load. The performance of the proposed structure is verified by measurement results. Natural load detection and covering 4 times bigger area than conventional topologies with a power transfer efficiency of 55% are the novelties of presented paper.

A new method for wideband characterization of resonator-based sensing platforms

NASA Astrophysics Data System (ADS)

Munir, Farasat; Wathen, Adam; Hunt, William D.

2011-03-01

A new approach to the electronic instrumentation for extracting data from resonator-based sensing devices (e.g., microelectromechanical, piezoelectric, electrochemical, and acoustic) is suggested and demonstrated here. Traditionally, oscillator-based circuitry is employed to monitor shift in the resonance frequency of the resonator. These circuits give a single point measurement at the frequency where the oscillation criterion is met. However, the resonator response itself is broadband and contains much more information than a single point measurement. Here, we present a method for the broadband characterization of a resonator using white noise as an excitation signal. The resonator is used in a two-port filter configuration, and the resonator output is subjected to frequency spectrum analysis. The result is a wideband spectral map analogous to the magnitude of the S21 parameters of a conventional filter. Compared to other sources for broadband excitation (e.g., frequency chirp, multisine, or narrow time domain pulse), the white noise source requires no design of the input signal and is readily available for very wide bandwidths (1 MHz-3 GHz). Moreover, it offers simplicity in circuit design as it does not require precise impedance matching; whereas such requirements are very strict for oscillator-based circuit systems, and can be difficult to fulfill. This results in a measurement system that does not require calibration, which is a significant advantage over oscillator circuits. Simulation results are first presented for verification of the proposed system, followed by measurement results with a prototype implementation. A 434 MHz surface acoustic wave (SAW) resonator and a 5 MHz quartz crystal microbalance (QCM) are measured using the proposed method, and the results are compared to measurements taken by a conventional bench-top network analyzer. Maximum relative differences in the measured resonance frequencies of the SAW and QCM resonators are 0.0004% and 0

A 10kW series resonant converter design, transistor characterization, and base-drive optimization

NASA Technical Reports Server (NTRS)

Robson, R.; Hancock, D.

1981-01-01

Transistors are characterized for use as switches in resonant circuit applications. A base drive circuit to provide the optimal base drive to these transistors under resonant circuit conditions is developed and then used in the design, fabrication and testing of a breadboard, spaceborne type 10 kW series resonant converter.

Magnetic Resonance-Based Electrical Property Tomography (MR-EPT) for Prostate Cancer Grade Imaging

DTIC Science & Technology

2016-07-01

Award Number: W81XWH-13-1-0127 TITLE: Magnetic Resonance-Based Electrical Property Tomography (MR- EPT) for Prostate Cancer Grade Imaging...SUBTITLE 5a. CONTRACT NUMBER W81XWH-13-1-0127 Magnetic Resonance-Based Electrical Property Tomography (MR- EPT) for Prostate Cancer Grade Imaging...developing Magnetic Resonance – Electrical Property Tomography (MR-EPT) specifically for prostate imaging. MR-EPT is an imaging modality that may enable

If It's Resonance, What is Resonating?

ERIC Educational Resources Information Center

Kerber, Robert C.

2006-01-01

The phenomenon under the name "resonance," which, is based on the mathematical analogy between mechanical resonance and the behavior of wave functions in quantum mechanical exchange phenomena was described. The resonating system does not have a structure intermediate between those involved in the resonance, but instead a structure which is further…

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

PubMed

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

2015-09-29

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

A microprocessor-based multichannel subsensory stochastic resonance electrical stimulator.

PubMed

Chang, Gwo-Ching

2013-01-01

Stochastic resonance electrical stimulation is a novel intervention which provides potential benefits for improving postural control ability in the elderly, those with diabetic neuropathy, and stroke patients. In this paper, a microprocessor-based subsensory white noise electrical stimulator for the applications of stochastic resonance stimulation is developed. The proposed stimulator provides four independent programmable stimulation channels with constant-current output, possesses linear voltage-to-current relationship, and has two types of stimulation modes, pulse amplitude and width modulation.

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

NASA Astrophysics Data System (ADS)

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

2017-01-01

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

Toroidal resonance based optical modulator employing hybrid graphene-dielectric metasurface.

PubMed

Liu, Gui-Dong; Zhai, Xiang; Xia, Sheng-Xuan; Lin, Qi; Zhao, Chu-Jun; Wang, Ling-Ling

2017-10-16

In this paper, we demonstrate the combination of a dielectric metasurface with a graphene layer to realize a high performance toroidal resonance based optical modulator. The dielectric metasurface consists of two mirrored asymmetric silicon split-ring resonators (ASSRRs) that can support strong toroidal dipolar resonance with narrow line width (~0.77 nm) and high quality (Q)-factor (~1702) and contrast ratio (~100%). Numerical simulation results show that the transmission amplitude of the toroidal dipolar resonance can be efficiently modulated by varying the Fermi energy EF when the graphene layer is integrated with the dielectric metasurface, and a max transmission coefficient difference up to 78% is achieved indicating that the proposed hybrid graphene/dielectric metasurface shows good performance as an optical modulator. The effects of the asymmetry degree of the ASSRRs on the toroidal dipolar resonance are studied and the efficiency of the transmission amplitude modulation of graphene is also investigated. Our results may also provide potential applications in optical filter and bio-chemical sensing.

An energy-efficient readout circuit for resonant sensors based on ring-down measurement

NASA Astrophysics Data System (ADS)

Zeng, Z.; Pertijs, M. A. P.; Karabacak, D. M.

2013-02-01

This paper presents an energy-efficient readout circuit for resonant sensors that operates based on a transient measurement method. The resonant sensor is driven at a frequency close to its resonance frequency by an excitation source that can be intermittently disconnected, causing the sensor to oscillate at its resonance frequency with exponentially decaying amplitude. By counting the zero crossings of this ring-down response, the interface circuit can detect the resonance frequency. In contrast with oscillator-based readout, the presented readout circuit is readily able to detect quality factor (Q) of the resonator from the envelope of the ring-down response, and can be used even in the presence of large parasitic capacitors. A prototype of the readout circuit has been integrated in 0.35 μm CMOS technology, and consumes only 36 μA from a 3.3 V supply during a measurement time of 2 ms. The resonance frequency and quality factor of a micro-machined SiN resonator obtained using this prototype are in good agreement with results obtained using impedance analysis. Furthermore, a clear transient response is observed to ethanol flow using the presented readout, demonstrating the use of this technique in sensing applications.

MEMS tunable optical filter based on multi-ring resonator

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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

Effect of angular velocity on sensors based on morphology dependent resonances.

PubMed

Ali, Amir R; Ioppolo, Tindaro

2014-04-22

We carried out an analysis to investigate the morphology dependent optical resonances shift (MDR) of a rotating spherical resonator. The spinning resonator experiences an elastic deformation due to the centrifugal force acting on it, leading to a shift in its MDR. Experiments are also carried out to demonstrate the MDR shifts of a spinning polydimethylsiloxane (PDMS) microsphere. The experimental results agree well with the analytical prediction. These studies demonstrated that spinning sensor based on MDR may experience sufficient shift in the optical resonances, therefore interfering with its desirable operational sensor design. Also the results show that angular velocity sensors could be designed using this principle.

Magnetic resonance imaging-compatible tactile sensing device based on a piezoelectric array.

PubMed

Hamed, Abbi; Masamune, Ken; Tse, Zion Tsz Ho; Lamperth, Michael; Dohi, Takeyoshi

2012-07-01

Minimally invasive surgery is a widely used medical technique, one of the drawbacks of which is the loss of direct sense of touch during the operation. Palpation is the use of fingertips to explore and make fast assessments of tissue morphology. Although technologies are developed to equip minimally invasive surgery tools with haptic feedback capabilities, the majority focus on tissue stiffness profiling and tool-tissue interaction force measurement. For greatly increased diagnostic capability, a magnetic resonance imaging-compatible tactile sensor design is proposed, which allows minimally invasive surgery to be performed under image guidance, combining the strong capability of magnetic resonance imaging soft tissue and intuitive palpation. The sensing unit is based on a piezoelectric sensor methodology, which conforms to the stringent mechanical and electrical design requirements imposed by the magnetic resonance environment The sensor mechanical design and the device integration to a 0.2 Tesla open magnetic resonance imaging scanner are described, together with the device's magnetic resonance compatibility testing. Its design limitations and potential future improvements are also discussed. A tactile sensing unit based on a piezoelectric sensor principle is proposed, which is designed for magnetic resonance imaging guided interventions.

Wafer scale formation of monocrystalline silicon-based Mie resonators via silicon-on-insulator dewetting.

PubMed

Abbarchi, Marco; Naffouti, Meher; Vial, Benjamin; Benkouider, Abdelmalek; Lermusiaux, Laurent; Favre, Luc; Ronda, Antoine; Bidault, Sébastien; Berbezier, Isabelle; Bonod, Nicolas

2014-11-25

Subwavelength-sized dielectric Mie resonators have recently emerged as a promising photonic platform, as they combine the advantages of dielectric microstructures and metallic nanoparticles supporting surface plasmon polaritons. Here, we report the capabilities of a dewetting-based process, independent of the sample size, to fabricate Si-based resonators over large scales starting from commercial silicon-on-insulator (SOI) substrates. Spontaneous dewetting is shown to allow the production of monocrystalline Mie-resonators that feature two resonant modes in the visible spectrum, as observed in confocal scattering spectroscopy. Homogeneous scattering responses and improved spatial ordering of the Si-based resonators are observed when dewetting is assisted by electron beam lithography. Finally, exploiting different thermal agglomeration regimes, we highlight the versatility of this technique, which, when assisted by focused ion beam nanopatterning, produces monocrystalline nanocrystals with ad hoc size, position, and organization in complex multimers.

Axicon based conical resonators with high power copper vapor laser.

PubMed

Singh, Bijendra; Subramaniam, V V; Daultabad, S R; Chakraborty, Ashim

2010-07-01

We report for the first time the performance of axicon based conical resonators (ABCRs) in a copper vapor laser, with novel results. The unstable conical resonator comprising of conical mirror (reflecting axicon) with axicon angle approximately pi/18, cone angle approximately 160 degrees, and a convex mirror of 60 cm radius of curvature was effective in reducing the average beam divergence to approximately 0.15 mrad (approximately 25 fold reduction compared to standard multimode plane-plane cavity) with output power of approximately 31 W. Extraction efficiency of approximately 50%-60% and beam divergence of <1 mrad was achieved in other stable ABCR configurations using flat and concave mirrors with the axicon. This is a significant improvement compared to 4-5 mrad normally observed in conventional stable resonators in copper vapor lasers. The conical resonators with copper vapor laser provide high misalignment tolerance beta approximately 4-5 mrad where beta is the tilt angle of the conical mirror from optimum position responsible for approximately 20% decline in laser power. The depth of focus d was approximately three times larger in case of conical resonator as compared to that of standard spherical unstable resonator under similar beam divergence and focusing conditions.

N× N optical switch based on cascaded microring resonators

NASA Astrophysics Data System (ADS)

Li, Jing-sen; Lu, Huan-yu; Zhao, Yu-lin

2018-05-01

An N×N optical switch based on cascaded microring resonators on chip is proposed. As an example, the 4×4 optical switch is further investigated. It is successfully demonstrated that its insertion loss is relatively low as 2.2 dB, the crosstalk is negligible, and the extinction ratio ( ER) is as large as 130 dB. Thermal tuning is employed to make the microrings be in resonance or not, which leads to a response time of several hundred microseconds. Alternatively, doping the desired waveguide regions with p-type or n-type dopants is able to achieve a better response time of several nanoseconds. The proposed design is easily integrated to a large scale with less microring resonators, which ensures the compact size and the low power consumption.

A Lateral Differential Resonant Pressure Microsensor Based on SOI-Glass Wafer-Level Vacuum Packaging.

PubMed

Xie, Bo; Xing, Yonghao; Wang, Yanshuang; Chen, Jian; Chen, Deyong; Wang, Junbo

2015-09-21

This paper presents the fabrication and characterization of a resonant pressure microsensor based on SOI-glass wafer-level vacuum packaging. The SOI-based pressure microsensor consists of a pressure-sensitive diaphragm at the handle layer and two lateral resonators (electrostatic excitation and capacitive detection) on the device layer as a differential setup. The resonators were vacuum packaged with a glass cap using anodic bonding and the wire interconnection was realized using a mask-free electrochemical etching approach by selectively patterning an Au film on highly topographic surfaces. The fabricated resonant pressure microsensor with dual resonators was characterized in a systematic manner, producing a quality factor higher than 10,000 (~6 months), a sensitivity of about 166 Hz/kPa and a reduced nonlinear error of 0.033% F.S. Based on the differential output, the sensitivity was increased to two times and the temperature-caused frequency drift was decreased to 25%.

Neutron Spin Resonance in the 112-Type Iron-Based Superconductor

NASA Astrophysics Data System (ADS)

Xie, Tao; Gong, Dongliang; Ghosh, Haranath; Ghosh, Abyay; Soda, Minoru; Masuda, Takatsugu; Itoh, Shinichi; Bourdarot, Frédéric; Regnault, Louis-Pierre; Danilkin, Sergey; Li, Shiliang; Luo, Huiqian

2018-03-01

We use inelastic neutron scattering to study the low-energy spin excitations of the 112-type iron pnictide Ca0.82La0.18Fe0.96Ni0.04As2 with bulk superconductivity below Tc=22 K . A two-dimensional spin resonance mode is found around E =11 meV , where the resonance energy is almost temperature independent and linearly scales with Tc along with other iron-based superconductors. Polarized neutron analysis reveals the resonance is nearly isotropic in spin space without any L modulations. Because of the unique monoclinic structure with additional zigzag arsenic chains, the As 4 p orbitals contribute to a three-dimensional hole pocket around the Γ point and an extra electron pocket at the X point. Our results suggest that the energy and momentum distribution of the spin resonance does not directly respond to the kz dependence of the fermiology, and the spin resonance intrinsically is a spin-1 mode from singlet-triplet excitations of the Cooper pairs in the case of weak spin-orbital coupling.

Neutron Spin Resonance in the 112-Type Iron-Based Superconductor.

PubMed

Xie, Tao; Gong, Dongliang; Ghosh, Haranath; Ghosh, Abyay; Soda, Minoru; Masuda, Takatsugu; Itoh, Shinichi; Bourdarot, Frédéric; Regnault, Louis-Pierre; Danilkin, Sergey; Li, Shiliang; Luo, Huiqian

2018-03-30

We use inelastic neutron scattering to study the low-energy spin excitations of the 112-type iron pnictide Ca_{0.82}La_{0.18}Fe_{0.96}Ni_{0.04}As_{2} with bulk superconductivity below T_{c}=22  K. A two-dimensional spin resonance mode is found around E=11  meV, where the resonance energy is almost temperature independent and linearly scales with T_{c} along with other iron-based superconductors. Polarized neutron analysis reveals the resonance is nearly isotropic in spin space without any L modulations. Because of the unique monoclinic structure with additional zigzag arsenic chains, the As 4p orbitals contribute to a three-dimensional hole pocket around the Γ point and an extra electron pocket at the X point. Our results suggest that the energy and momentum distribution of the spin resonance does not directly respond to the k_{z} dependence of the fermiology, and the spin resonance intrinsically is a spin-1 mode from singlet-triplet excitations of the Cooper pairs in the case of weak spin-orbital coupling.

Riemann-Hilbert technique scattering analysis of metamaterial-based asymmetric 2D open resonators

NASA Astrophysics Data System (ADS)

Kamiński, Piotr M.; Ziolkowski, Richard W.; Arslanagić, Samel

2017-12-01

The scattering properties of metamaterial-based asymmetric two-dimensional open resonators excited by an electric line source are investigated analytically. The resonators are, in general, composed of two infinite and concentric cylindrical layers covered with an infinitely thin, perfect conducting shell that has an infinite axial aperture. The line source is oriented parallel to the cylinder axis. An exact analytical solution of this problem is derived. It is based on the dual-series approach and its transformation to the equivalent Riemann-Hilbert problem. Asymmetric metamaterial-based configurations are found to lead simultaneously to large enhancements of the radiated power and to highly steerable Huygens-like directivity patterns; properties not attainable with the corresponding structurally symmetric resonators. The presented open resonator designs are thus interesting candidates for many scientific and engineering applications where enhanced directional near- and far-field responses, tailored with beam shaping and steering capabilities, are highly desired.

A Lateral Differential Resonant Pressure Microsensor Based on SOI-Glass Wafer-Level Vacuum Packaging

PubMed Central

Xie, Bo; Xing, Yonghao; Wang, Yanshuang; Chen, Jian; Chen, Deyong; Wang, Junbo

2015-01-01

This paper presents the fabrication and characterization of a resonant pressure microsensor based on SOI-glass wafer-level vacuum packaging. The SOI-based pressure microsensor consists of a pressure-sensitive diaphragm at the handle layer and two lateral resonators (electrostatic excitation and capacitive detection) on the device layer as a differential setup. The resonators were vacuum packaged with a glass cap using anodic bonding and the wire interconnection was realized using a mask-free electrochemical etching approach by selectively patterning an Au film on highly topographic surfaces. The fabricated resonant pressure microsensor with dual resonators was characterized in a systematic manner, producing a quality factor higher than 10,000 (~6 months), a sensitivity of about 166 Hz/kPa and a reduced nonlinear error of 0.033% F.S. Based on the differential output, the sensitivity was increased to two times and the temperature-caused frequency drift was decreased to 25%. PMID:26402679

Resonant transition-based quantum computation

NASA Astrophysics Data System (ADS)

Chiang, Chen-Fu; Hsieh, Chang-Yu

2017-05-01

In this article we assess a novel quantum computation paradigm based on the resonant transition (RT) phenomenon commonly associated with atomic and molecular systems. We thoroughly analyze the intimate connections between the RT-based quantum computation and the well-established adiabatic quantum computation (AQC). Both quantum computing frameworks encode solutions to computational problems in the spectral properties of a Hamiltonian and rely on the quantum dynamics to obtain the desired output state. We discuss how one can adapt any adiabatic quantum algorithm to a corresponding RT version and the two approaches are limited by different aspects of Hamiltonians' spectra. The RT approach provides a compelling alternative to the AQC under various circumstances. To better illustrate the usefulness of the novel framework, we analyze the time complexity of an algorithm for 3-SAT problems and discuss straightforward methods to fine tune its efficiency.

Tunable nano-scale graphene-based devices in mid-infrared wavelengths composed of cylindrical resonators

NASA Astrophysics Data System (ADS)

Asgari, Somayyeh; Ghattan Kashani, Zahra; Granpayeh, Nosrat

2018-04-01

The performances of three optical devices including a refractive index sensor, a power splitter, and a 4-channel multi/demultiplexer based on graphene cylindrical resonators are proposed, analyzed, and simulated numerically by using the finite-difference time-domain method. The proposed sensor operates on the principle of the shift in resonance wavelength with a change in the refractive index of dielectric materials. The sensor sensitivity has been numerically derived. In addition, the performances of the power splitter and the multi/demultiplexer based on the variation of the resonance wavelengths of cylindrical resonator have been thoroughly investigated. The simulation results are in good agreement with the theoretical ones. Our studies demonstrate that the graphene based ultra-compact, nano-scale devices can be improved to be used as photonic integrated devices, optical switching, and logic gates.

An all-optical switch based on a surface plasmon polariton resonator

NASA Astrophysics Data System (ADS)

Pan, Zijuan; Lang, Peilin; Duan, Gaoyan

2018-04-01

All-optical switch is one of the key parts of optical circuit. We employ a temperature-sensitive resonator to form an optical switch. The resonator deforms under the applied light and adjusts the transmittance of the structure. To our knowledge, this is the first design of an all-optical surface plasmon polariton (SPP) switch based on the heat deformation effect.

Electromagnetically induced transparency in planar metamaterials based on guided mode resonance

NASA Astrophysics Data System (ADS)

Sun, Yaru; Chen, Hang; Li, Xiangjun; Hong, Zhi

2017-06-01

We present and numerically demonstrate a novel, electromagnetically induced transparency (EIT) in planar metamaterials (MMs) based on guided mode resonance (GMR). The unit cell of the MM consists of two metallic ring resonators. The GMR with high quality factor (Q) is achieved by changing the distance between the two rings of the MM. Narrow EIT-like spectral response is realized by coupling between a high Q GMR and a low Q dipolar resonance of the MM. Our work could provide another efficient way towards the realization of EIT with large group index using very simple structures.

Stochastic resonance based on modulation instability in spatiotemporal chaos.

PubMed

Han, Jing; Liu, Hongjun; Huang, Nan; Wang, Zhaolu

2017-04-03

A novel dynamic of stochastic resonance in spatiotemporal chaos is presented, which is based on modulation instability of perturbed partially coherent wave. The noise immunity of chaos can be reinforced through this effect and used to restore the coherent signal information buried in chaotic perturbation. A theoretical model with fluctuations term is derived from the complex Ginzburg-Landau equation via Wigner transform. It shows that through weakening the nonlinear threshold and triggering energy redistribution, the coherent component dominates the instability damped by incoherent component. The spatiotemporal output showing the properties of stochastic resonance may provide a potential application of signal encryption and restoration.

A personal computer-based nuclear magnetic resonance spectrometer

NASA Astrophysics Data System (ADS)

Job, Constantin; Pearson, Robert M.; Brown, Michael F.

1994-11-01

Nuclear magnetic resonance (NMR) spectroscopy using personal computer-based hardware has the potential of enabling the application of NMR methods to fields where conventional state of the art equipment is either impractical or too costly. With such a strategy for data acquisition and processing, disciplines including civil engineering, agriculture, geology, archaeology, and others have the possibility of utilizing magnetic resonance techniques within the laboratory or conducting applications directly in the field. Another aspect is the possibility of utilizing existing NMR magnets which may be in good condition but unused because of outdated or nonrepairable electronics. Moreover, NMR applications based on personal computer technology may open up teaching possibilities at the college or even secondary school level. The goal of developing such a personal computer (PC)-based NMR standard is facilitated by existing technologies including logic cell arrays, direct digital frequency synthesis, use of PC-based electrical engineering software tools to fabricate electronic circuits, and the use of permanent magnets based on neodymium-iron-boron alloy. Utilizing such an approach, we have been able to place essentially an entire NMR spectrometer console on two printed circuit boards, with the exception of the receiver and radio frequency power amplifier. Future upgrades to include the deuterium lock and the decoupler unit are readily envisioned. The continued development of such PC-based NMR spectrometers is expected to benefit from the fast growing, practical, and low cost personal computer market.

Capacitor-based detection of nuclear magnetization: nuclear quadrupole resonance of surfaces.

PubMed

Gregorovič, Alan; Apih, Tomaž; Kvasić, Ivan; Lužnik, Janko; Pirnat, Janez; Trontelj, Zvonko; Strle, Drago; Muševič, Igor

2011-03-01

We demonstrate excitation and detection of nuclear magnetization in a nuclear quadrupole resonance (NQR) experiment with a parallel plate capacitor, where the sample is located between the two capacitor plates and not in a coil as usually. While the sensitivity of this capacitor-based detection is found lower compared to an optimal coil-based detection of the same amount of sample, it becomes comparable in the case of very thin samples and even advantageous in the proximity of conducting bodies. This capacitor-based setup may find its application in acquisition of NQR signals from the surface layers on conducting bodies or in a portable tightly integrated nuclear magnetic resonance sensor. Copyright © 2010 Elsevier Inc. All rights reserved.

A resonant force sensor based on ionic polymer metal composites

NASA Astrophysics Data System (ADS)

Bonomo, Claudia; Fortuna, Luigi; Giannone, Pietro; Graziani, Salvatore; Strazzeri, Salvatore

2008-02-01

In this paper a novel force sensor, based on ionic polymer metal composites (IPMCs), is presented. The system has DC sensing capabilities and is able to work in the range of a few millinewtons. IPMCs are emerging materials used to realize motion actuators and sensors. An IPMC strip is activated in a beam fixed/simply-supported configuration. The beam is tightened at the simply-supported end by a force. This influences the natural resonant frequency of the beam; the value of the resonant frequency is used in the proposed system to estimate the force applied in the axial direction. The performance of the system based on the IPMC material has proved to be comparable with that of sensors based on other sensing mechanisms. This suggests the possibility of using this class of polymeric devices to realize PMEMS (plastic micro electrical mechanical systems) sensors.

Atomic-resolution single-spin magnetic resonance detection concept based on tunneling force microscopy

NASA Astrophysics Data System (ADS)

Payne, A.; Ambal, K.; Boehme, C.; Williams, C. C.

2015-05-01

A study of a force detected single-spin magnetic resonance measurement concept with atomic spatial resolution is presented. The method is based upon electrostatic force detection of spin-selection rule controlled single-electron tunneling between two electrically isolated paramagnetic states. Single-spin magnetic resonance detection is possible by measuring the force detected tunneling charge noise on and off spin resonance. Simulation results of this charge noise, based upon physical models of the tunneling and spin physics, are directly compared to measured atomic force microscopy system noise. The results show that the approach could provide single-spin measurement of electrically isolated qubit states with atomic spatial resolution at room temperature.

Microwave Oscillators Based on Nonlinear WGM Resonators

NASA Technical Reports Server (NTRS)

Maleki, Lute; Matsko, Andrey; Savchenkov, Anatoliy; Strekalov, Dmitry

2006-01-01

Optical oscillators that exploit resonantly enhanced four-wave mixing in nonlinear whispering-gallery-mode (WGM) resonators are under investigation for potential utility as low-power, ultra-miniature sources of stable, spectrally pure microwave signals. There are numerous potential uses for such oscillators in radar systems, communication systems, and scientific instrumentation. The resonator in an oscillator of this type is made of a crystalline material that exhibits cubic Kerr nonlinearity, which supports the four-photon parametric process also known as four-wave mixing. The oscillator can be characterized as all-optical in the sense that the entire process of generation of the microwave signal takes place within the WGM resonator. The resonantly enhanced four-wave mixing yields coherent, phase-modulated optical signals at frequencies governed by the resonator structure. The frequency of the phase-modulation signal, which is in the microwave range, equals the difference between the frequencies of the optical signals; hence, this frequency is also governed by the resonator structure. Hence, further, the microwave signal is stable and can be used as a reference signal. The figure schematically depicts the apparatus used in a proof-of-principle experiment. Linearly polarized pump light was generated by an yttrium aluminum garnet laser at a wavelength of 1.32 microns. By use of a 90:10 fiber-optic splitter and optical fibers, some of the laser light was sent into a delay line and some was transmitted to one face of glass coupling prism, that, in turn, coupled the laser light into a crystalline CaF2 WGM disk resonator that had a resonance quality factor (Q) of 6x10(exp 9). The output light of the resonator was collected via another face of the coupling prism and a single-mode optical fiber, which transmitted the light to a 50:50 fiber-optic splitter. One output of this splitter was sent to a slow photodiode to obtain a DC signal for locking the laser to a particular

An acousto-optic sensor based on resonance grating waveguide structure

PubMed Central

Xie, Antonio Jou; Song, Fuchuan; Seo, Sang-Woo

2014-01-01

This paper presents an acousto-optic (AO) sensor based on resonance grating waveguide structure. The sensor is fabricated using elastic polymer materials to achieve a good sensitivity to ultrasound pressure waves. Ultrasound pressure waves modify the structural parameters of the sensor and result in the optical resonance shift of the sensor. This converts into a light intensity modulation. A commercial ultrasound transducer at 20 MHz is used to characterize a fabricated sensor and detection sensitivity at different optical source wavelength within a resonance spectrum is investigated. Practical use of the sensor at a fixed optical source wavelength is presented. Ultimately, the geometry of the planar sensor structure is suitable for two-dimensional, optical pressure imaging applications such as pressure wave detection and mapping, and ultrasound imaging. PMID:25045203

Fiber ring resonator based opto-electronic oscillator: phase noise optimisation and thermal stability study

NASA Astrophysics Data System (ADS)

Saleh, K.; Bouchier, A.; Merrer, P. H.; Llopis, O.; Cibiel, G.

2011-03-01

In the microwave domain and among many other advantages, optics represents an elegant solution to increase the quality Q factor in a system. Different types of optical resonators lead to Q factors above 109, and these resonators can be used as an alternative to optical delay lines to set up the frequency in optoelectronic oscillators (OEO). However, microwave-optics is also a complex field, and if the use of optical resonators in high spectral purity frequency generation systems like OEO has been already demonstrated, many aspects of these OEOs are still incompletely understood, especially the contribution to the oscillator phase noise of the different optical and microwave elements used in the oscillator system. In order to improve the phase noise of a fiber ring resonator based OEO, this oscillator has been theoretically studied in term of white frequency noise. In this paper, we present a theoretical study that has lead us to optimize a fiber ring resonator and the experimental phase noise results obtained for an OEO based on an optimized optical resonator. The OEO thermal stability is also investigated in this paper.

Optimal antibunching in passive photonic devices based on coupled nonlinear resonators

NASA Astrophysics Data System (ADS)

Ferretti, S.; Savona, V.; Gerace, D.

2013-02-01

We propose the use of weakly nonlinear passive materials for prospective applications in integrated quantum photonics. It is shown that strong enhancement of native optical nonlinearities by electromagnetic field confinement in photonic crystal resonators can lead to single-photon generation only exploiting the quantum interference of two coupled modes and the effect of photon blockade under resonant coherent driving. For realistic system parameters in state of the art microcavities, the efficiency of such a single-photon source is theoretically characterized by means of the second-order correlation function at zero-time delay as the main figure of merit, where major sources of loss and decoherence are taken into account within a standard master equation treatment. These results could stimulate the realization of integrated quantum photonic devices based on non-resonant material media, fully integrable with current semiconductor technology and matching the relevant telecom band operational wavelengths, as an alternative to single-photon nonlinear devices based on cavity quantum electrodynamics with artificial atoms or single atomic-like emitters.

A new imaging technique based on resonance for arterial vessels

NASA Astrophysics Data System (ADS)

Zhang, Xiaoming; Fatemi, Mostafa; Greenleaf, James F.

2003-04-01

Vibro-acoustography is a new noncontact imaging method based on the radiation force of ultrasound. We extend this technique for imaging of arterial vessels based on vibration resonance. The arterial vessel is excited remotely by ultrasound at a resonant frequency, at which the vibration of the vessel as well as its transmission to the body surface are large enough to be measured. By scanning the ultrasound beam across the vessel plane and measuring the vibration at one single point on the body or vessel surface, an image of the interior artery can be mapped. Theory is developed that predicts the measured velocity is proportional to the value of the mode shape at resonance. Experimental studies were carried out on a silicone tube embedded in a cylindrical gel phantom of large radius, which simulates a large artery and the surrounding body. The fundamental frequency was measured at which the ultrasound transducer scanned across the tube plane with velocity measurement at one single point on the tube or on the phantom by laser. The images obtained show clearly the interior tube and the modal shape of the tube. The present technique offers a new imaging method for arterial vessels.

Optimization of coupled device based on optical fiber with crystalline and integrated resonators

NASA Astrophysics Data System (ADS)

Bassir, David; Salzenstein, Patrice; Zhang, Mingjun

2017-05-01

Because of the advantages in terms of reproducibility for optical resonators on chip which are designed of various topologies and integration with optical devices. To increase the Q-factor from the lower rang [104 - 106 ] to higher one [108 -1010] [1-4] one use crystalline resonators. It is much complicated to couple an optical signal from a tapered fiber to crystalline resonator than from a defined ridge to a resonator designed on a chip. In this work, we will focus on the optimization of the crystalline resonators under straight wave guide (based on COMSOL multi-physic software) [5- 7] and subject also to technological constraints of manufacturing. The coupling problem at the Nano scale makes our optimizations problem more dynamics in term of design space.

The Tracking Resonance Frequency Method for Photoacoustic Measurements Based on the Phase Response

NASA Astrophysics Data System (ADS)

Suchenek, Mariusz

2017-04-01

One of the major issues in the use of the resonant photoacoustic cell is the resonance frequency of the cell. The frequency is not stable, and its changes depend mostly on temperature and gas mixture. This paper presents a new method for tracking resonance frequency, where both the amplitude and phase are calculated from the input samples. The stimulating frequency can be adjusted to the resonance frequency of the cell based on the phase. This method was implemented using a digital measurement system with an analog to digital converter, field programmable gate array (FPGA) and a microcontroller. The resonance frequency was changed by the injection of carbon dioxide into the cell. A theoretical description and experimental results are also presented.

Silicon cross-connect filters using microring resonator coupled multimode-interference-based waveguide crossings.

PubMed

Xu, Fang; Poon, Andrew W

2008-06-09

We report silicon cross-connect filters using microring resonator coupled multimode-interference (MMI) based waveguide crossings. Our experiments reveal that the MMI-based cross-connect filters impose lower crosstalk at the crossing than the conventional cross-connect filters using plain crossings, while offering a nearly symmetric resonance line shape in the drop-port transmission. As a proof-of-concept for cross-connection applications, we demonstrate on a silicon-on-insulator substrate (i) a 4-channel 1 x 4 linear-cascaded MMI-based cross-connect filter, and (ii) a 2-channel 2 x 2 array-cascaded MMI-based cross-connect filter.

Clinical implications of a multiparametric magnetic resonance imaging based nomogram applied to prostate cancer active surveillance.

PubMed

Siddiqui, M Minhaj; Truong, Hong; Rais-Bahrami, Soroush; Stamatakis, Lambros; Logan, Jennifer; Walton-Diaz, Annerleim; Turkbey, Baris; Choyke, Peter L; Wood, Bradford J; Simon, Richard M; Pinto, Peter A

2015-06-01

Multiparametric magnetic resonance imaging may be beneficial in the search for rational ways to decrease prostate cancer intervention in patients on active surveillance. We applied a previously generated nomogram based on multiparametric magnetic resonance imaging to predict active surveillance eligibility based on repeat biopsy outcomes. We reviewed the records of 85 patients who met active surveillance criteria at study entry based on initial biopsy and who then underwent 3.0 Tesla multiparametric magnetic resonance imaging with subsequent magnetic resonance imaging/ultrasound fusion guided prostate biopsy between 2007 and 2012. We assessed the accuracy of a previously published nomogram in patients on active surveillance before confirmatory biopsy. For each cutoff we determined the number of biopsies avoided (ie reliance on magnetic resonance imaging alone without rebiopsy) over the full range of nomogram cutoffs. We assessed the performance of the multiparametric magnetic resonance imaging active surveillance nomogram based on a decision to perform biopsy at various nomogram generated probabilities. Based on cutoff probabilities of 19% to 32% on the nomogram the number of patients who could be spared repeat biopsy was 27% to 68% of the active surveillance cohort. The sensitivity of the test in this interval was 97% to 71% and negative predictive value was 91% to 81%. Multiparametric magnetic resonance imaging based nomograms may reasonably decrease the number of repeat biopsies in patients on active surveillance by as much as 68%. Analysis over the full range of nomogram generated probabilities allows patient and caregiver preference based decision making on the risk assumed for the benefit of fewer repeat biopsies. Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Research on SOI-based micro-resonator devices

NASA Astrophysics Data System (ADS)

Xiao, Xi; Xu, Haihua; Hu, Yingtao; Zhou, Liang; Xiong, Kang; Li, Zhiyong; Li, Yuntao; Fan, Zhongchao; Han, Weihua; Yu, Yude; Yu, Jinzhong

2010-10-01

SOI (silicon-on-insulator)-based micro-resonator is the key building block of silicon photonics, which is considered as a promising solution to alleviate the bandwidth bottleneck of on-chip interconnects. Silicon-based sub-micron waveguide, microring and microdisk devices are investigated in Institute of Semiconductors, Chinese Academy of Sciences. The main progress in recent years is presented in this talk, such as high Q factor single mode microdisk filters, compact thirdorder microring filters with the through/drop port extinctions to be ~ 30/40 dB, fast microring electro-optical switches with the switch time of < 400 ps and crosstalk < -23 dB, and > 10 Gbit/s high speed microring modulators.

Graphene-based chemiluminescence resonance energy transfer for homogeneous immunoassay.

PubMed

Lee, Joon Seok; Joung, Hyou-Arm; Kim, Min-Gon; Park, Chan Beum

2012-04-24

We report on chemiluminescence resonance energy transfer (CRET) between graphene nanosheets and chemiluminescent donors. In contrast to fluorescence resonance energy transfer, CRET occurs via nonradiative dipole-dipole transfer of energy from a chemiluminescent donor to a suitable acceptor molecule without an external excitation source. We designed a graphene-based CRET platform for homogeneous immunoassay of C-reactive protein (CRP), a key marker for human inflammation and cardiovascular diseases, using a luminol/hydrogen peroxide chemiluminescence (CL) reaction catalyzed by horseradish peroxidase. According to our results, anti-CRP antibody conjugated to graphene nanosheets enabled the capture of CRP at the concentration above 1.6 ng mL(-1). In the CRET platform, graphene played a key role as an energy acceptor, which was more efficient than graphene oxide, while luminol served as a donor to graphene, triggering the CRET phenomenon between luminol and graphene. The graphene-based CRET platform was successfully applied to the detection of CRP in human serum samples in the range observed during acute inflammatory stress.

Magnetic resonance imaging based functional imaging in paediatric oncology.

PubMed

Manias, Karen A; Gill, Simrandip K; MacPherson, Lesley; Foster, Katharine; Oates, Adam; Peet, Andrew C

2017-02-01

Imaging is central to management of solid tumours in children. Conventional magnetic resonance imaging (MRI) is the standard imaging modality for tumours of the central nervous system (CNS) and limbs and is increasingly used in the abdomen. It provides excellent structural detail, but imparts limited information about tumour type, aggressiveness, metastatic potential or early treatment response. MRI based functional imaging techniques, such as magnetic resonance spectroscopy, diffusion and perfusion weighted imaging, probe tissue properties to provide clinically important information about metabolites, structure and blood flow. This review describes the role of and evidence behind these functional imaging techniques in paediatric oncology and implications for integrating them into routine clinical practice. Copyright © 2016 Elsevier Ltd. All rights reserved.

Theoretical modeling of a coupled plasmon waveguide resonance sensor based on multimode optical fiber

NASA Astrophysics Data System (ADS)

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

2018-03-01

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.

Mass spectrometry based on a coupled Cooper-pair box and nanomechanical resonator system

NASA Astrophysics Data System (ADS)

Jiang, Cheng; Chen, Bin; Li, Jin-Jin; Zhu, Ka-Di

2011-10-01

Nanomechanical resonators (NRs) with very high frequency have a great potential for mass sensing with unprecedented sensitivity. In this study, we propose a scheme for mass sensing based on the NR capacitively coupled to a Cooper-pair box (CPB) driven by two microwave currents. The accreted mass landing on the resonator can be measured conveniently by tracking the resonance frequency shifts because of mass changes in the signal absorption spectrum. We demonstrate that frequency shifts induced by adsorption of ten 1587 bp DNA molecules can be well resolved in the absorption spectrum. Integration with the CPB enables capacitive readout of the mechanical resonance directly on the chip.

Miniature Trace Gas Detector Based on Microfabricated Optical Resonators

NASA Technical Reports Server (NTRS)

Aveline, David C.; Yu, Nan; Thompson, Robert J.; Strekalov, Dmitry V.

2013-01-01

While a variety of techniques exist to monitor trace gases, methods relying on absorption of laser light are the most commonly used in terrestrial applications. Cavity-enhanced absorption techniques typically use high-reflectivity mirrors to form a resonant cavity, inside of which a sample gas can be analyzed. The effective absorption length is augmented by the cavity's high quality factor, or Q, because the light reflects many times between the mirrors. The sensitivity of such mirror-based sensors scales with size, generally making them somewhat bulky in volume. Also, specialized coatings for the high-reflectivity mirrors have limited bandwidth (typically just a few nanometers), and the delicate mirror surfaces can easily be degraded by dust or chemical films. As a highly sensitive and compact alternative, JPL is developing a novel trace gas sensor based on a monolithic optical resonator structure that has been modified such that a gas sample can be directly injected into the cavity. This device concept combines ultra-high Q optical whispering gallery mode resonators (WGMR) with microfabrication technology used in the semiconductor industry. For direct access to the optical mode inside a resonator, material can be precisely milled from its perimeter, creating an open gap within the WGMR. Within this open notch, the full optical mode of the resonator can be accessed. While this modification may limit the obtainable Q, calculations show that the reduction is not significant enough to outweigh its utility for trace gas detection. The notch can be milled from the high- Q crystalline WGMR with a focused ion beam (FIB) instrument with resolution much finer than an optical wavelength, thereby minimizing scattering losses and preserving the optical quality. Initial experimental demonstrations have shown that these opened cavities still support high-Q whispering gallery modes. This technology could provide ultrasensitive detection of a variety of molecular species in an

Biochemical component identification by plasmonic improved whispering gallery mode optical resonance based sensor

NASA Astrophysics Data System (ADS)

Saetchnikov, Vladimir A.; Tcherniavskaia, Elina A.; Saetchnikov, Anton V.; Schweiger, Gustav; Ostendorf, Andreas

2014-05-01

Experimental data on detection and identification of variety of biochemical agents, such as proteins, microelements, antibiotic of different generation etc. in both single and multi component solutions under varied in wide range concentration analyzed on the light scattering parameters of whispering gallery mode optical resonance based sensor are represented. Multiplexing on parameters and components has been realized using developed fluidic sensor cell with fixed in adhesive layer dielectric microspheres and data processing. Biochemical component identification has been performed by developed network analysis techniques. Developed approach is demonstrated to be applicable both for single agent and for multi component biochemical analysis. Novel technique based on optical resonance on microring structures, plasmon resonance and identification tools has been developed. To improve a sensitivity of microring structures microspheres fixed by adhesive had been treated previously by gold nanoparticle solution. Another technique used thin film gold layers deposited on the substrate below adhesive. Both biomolecule and nanoparticle injections caused considerable changes of optical resonance spectra. Plasmonic gold layers under optimized thickness also improve parameters of optical resonance spectra. Biochemical component identification has been also performed by developed network analysis techniques both for single and for multi component solution. So advantages of plasmon enhancing optical microcavity resonance with multiparameter identification tools is used for development of a new platform for ultra sensitive label-free biomedical sensor.

Multi-resonant electromagnetic shunt in base isolation for vibration damping and energy harvesting

NASA Astrophysics Data System (ADS)

Pei, Yalu; Liu, Yilun; Zuo, Lei

2018-06-01

This paper investigates multi-resonant electromagnetic shunts applied to base isolation for dual-function vibration damping and energy harvesting. Two multi-mode shunt circuit configurations, namely parallel and series, are proposed and optimized based on the H2 criteria. The root-mean-square (RMS) value of the relative displacement between the base and the primary structure is minimized. Practically, this will improve the safety of base-isolated buildings subjected the broad bandwidth ground acceleration. Case studies of a base-isolated building are conducted in both the frequency and time domains to investigate the effectiveness of multi-resonant electromagnetic shunts under recorded earthquake signals. It shows that both multi-mode shunt circuits outperform traditional single mode shunt circuits by suppressing the first and the second vibration modes simultaneously. Moreover, for the same stiffness ratio, the parallel shunt circuit is more effective at harvesting energy and suppressing vibration, and can more robustly handle parameter mistuning than the series shunt circuit. Furthermore, this paper discusses experimental validation of the effectiveness of multi-resonant electromagnetic shunts for vibration damping and energy harvesting on a scaled-down base isolation system.

Insect-inspired wing actuation structures based on ring-type resonators

NASA Astrophysics Data System (ADS)

Bolsman, Caspar T.; Goosen, Johannes F. L.; van Keulen, Fred

2008-03-01

In this paper, we illustrate and study the opportunities of resonant ring type structures as wing actuation mechanisms for a flapping wing Micro Air Vehicle (MAV). Various design alternatives are presented and studied based on computational and physical models. Insects provide an excellent source of inspiration for the development of the wing actuation mechanisms for flapping wing MAVs. The insect thorax is a structure which in essence provides a mechanism to couple the wing muscles to the wings while offering weight reduction through application of resonance, using tailored elasticity. The resonant properties of the thorax are a very effective way to reducing the power expenditure of wing movement. The wing movement itself is fairly complex and is guided by a set of control muscles and thoracic structures which are present in proximity of the wing root. The development of flapping wing MAVs requires a move away from classical structures and actuators. The use of gears and rotational electric motors is hard to justify at the small scale. Resonant structures provide a large design freedom whilst also providing various options for actuation. The move away from deterministic mechanisms offers possibilities for mass reduction.

Dielectrically-Loaded Cylindrical Resonator-Based Wireless Passive High-Temperature Sensor

PubMed Central

Xiong, Jijun; Wu, Guozhu; Tan, Qiulin; Wei, Tanyong; Wu, Dezhi; Shen, Sanmin; Dong, Helei; Zhang, Wendong

2016-01-01

The temperature sensor presented in this paper is based on a microwave dielectric resonator, which uses alumina ceramic as a substrate to survive in harsh environments. The resonant frequency of the resonator is determined by the relative permittivity of the alumina ceramic, which monotonically changes with temperature. A rectangular aperture etched on the surface of the resonator works as both an incentive and a coupling device. A broadband slot antenna fed by a coplanar waveguide is utilized as an interrogation antenna to wirelessly detect the sensor signal using a radio-frequency backscattering technique. Theoretical analysis, software simulation, and experiments verified the feasibility of this temperature-sensing system. The sensor was tested in a metal-enclosed environment, which severely interferes with the extraction of the sensor signal. Therefore, frequency-domain compensation was introduced to filter the background noise and improve the signal-to-noise ratio of the sensor signal. The extracted peak frequency was found to monotonically shift from 2.441 to 2.291 GHz when the temperature was varied from 27 to 800 °C, leading to an average absolute sensitivity of 0.19 MHz/°C. PMID:27916920

Nanomechanical resonators based on group IV element monolayers

NASA Astrophysics Data System (ADS)

He, Ji-Dong; Sun, Jia-Sheng; Jiang, Jin-Wu

2018-04-01

We perform molecular dynamics simulations to investigate the energy dissipation of the resonant oscillation for the group IV monolayers of puckered configuration, in which the oscillation is driven with different actuation velocities. We find that, in the moderate actuation velocity regime, the nonlinear coupling between the resonant oscillation mode and other high-frequency modes will lead to the non-resonant motion of the system. For the larger actuation velocity, the effective strain generated during the resonant oscillating causes a structural transition from the puckered configuration into the planar configuration, which is a characteristic energy dissipation mechanism for the resonant oscillation of these group IV puckered monolayers. Our findings shed light on mechanical applications of the group IV monolayers in the nanomechanical resonator field.

Study of node and mass sensitivity of resonant mode based cantilevers with concentrated mass loading

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Kewei, E-mail: drzkw@126.com; Chai, Yuesheng; Fu, Jiahui

2015-12-15

Resonant-mode based cantilevers are an important type of acoustic wave based mass-sensing devices. In this work, the governing vibration equation of a bi-layer resonant-mode based cantilever attached with concentrated mass is established by using a modal analysis method. The effects of resonance modes and mass loading conditions on nodes and mass sensitivity of the cantilever were theoretically studied. The results suggested that the node did not shift when concentrated mass was loaded on a specific position. Mass sensitivity of the cantilever was linearly proportional to the square of the point displacement at the mass loading position for all the resonancemore » modes. For the first resonance mode, when mass loading position x{sub c} satisfied 0 < x{sub c} < ∼ 0.3l (l is the cantilever beam length and 0 represents the rigid end), mass sensitivity decreased as the mass increasing while the opposite trend was obtained when mass loading satisfied ∼0.3l ≤ x{sub c} ≤ l. Mass sensitivity did not change when concentrated mass was loaded at the rigid end. This work can provide scientific guidance to optimize the mass sensitivity of a resonant-mode based cantilever.« less

Characterization of micro-resonator based on enhanced metal insulator semiconductor capacitor for glucose recognition.

PubMed

Dhakal, Rajendra; Kim, E S; Jo, Yong-Hwa; Kim, Sung-Soo; Kim, Nam-Young

2017-03-01

We present a concept for the characterization of micro-fabricated based resonator incorporating air-bridge metal-insulator-semiconductor (MIS) capacitor to continuously monitor an individual's state of glucose levels based on frequency variation. The investigation revealed that, the micro-resonator based on MIS capacitor holds considerable promise for implementation and recognition as a glucose sensor for human serum. The discrepancy in complex permittivity as a result of enhanced capacitor was achieved for the detection and determination of random glucose concentration levels using a unique variation of capacitor that indeed results in an adequate variation of the resonance frequency. Moreover, the design and development of micro-resonator with enhanced MIS capacitor generate a resolution of 112.38 × 10 -3 pF/mg/dl, minimum detectable glucose level of 7.45mg/dl, and a limit of quantification of 22.58mg/dl. Additionally, this unique approach offers long-term reliability for mediator-free glucose sensing with a relative standard deviation of less than 0.5%. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

Study on frequency characteristics of wireless power transmission system based on magnetic coupling resonance

NASA Astrophysics Data System (ADS)

Liang, L. H.; Liu, Z. Z.; Hou, Y. J.; Zeng, H.; Yue, Z. K.; Cui, S.

2017-11-01

In order to study the frequency characteristics of the wireless energy transmission system based on the magnetic coupling resonance, a circuit model based on the magnetic coupling resonant wireless energy transmission system is established. The influence of the load on the frequency characteristics of the wireless power transmission system is analysed. The circuit coupling theory is used to derive the minimum load required to suppress frequency splitting. Simulation and experimental results verify that when the load size is lower than a certain value, the system will appear frequency splitting, increasing the load size can effectively suppress the frequency splitting phenomenon. The power regulation scheme of the wireless charging system based on magnetic coupling resonance is given. This study provides a theoretical basis for load selection and power regulation of wireless power transmission systems.

Electromechanical oscillations in bilayer graphene

PubMed Central

Benameur, Muhammed M.; Gargiulo, Fernando; Manzeli, Sajedeh; Autès, Gabriel; Tosun, Mahmut; Yazyev, Oleg V.; Kis, Andras

2015-01-01

Nanoelectromechanical systems constitute a class of devices lying at the interface between fundamental research and technological applications. Realizing nanoelectromechanical devices based on novel materials such as graphene allows studying their mechanical and electromechanical characteristics at the nanoscale and addressing fundamental questions such as electron–phonon interaction and bandgap engineering. In this work, we realize electromechanical devices using single and bilayer graphene and probe the interplay between their mechanical and electrical properties. We show that the deflection of monolayer graphene nanoribbons results in a linear increase in their electrical resistance. Surprisingly, we observe oscillations in the electromechanical response of bilayer graphene. The proposed theoretical model suggests that these oscillations arise from quantum mechanical interference in the transition region induced by sliding of individual graphene layers with respect to each other. Our work shows that bilayer graphene conceals unexpectedly rich and novel physics with promising potential in applications based on nanoelectromechanical systems. PMID:26481767

Graphene based resonance structure to enhance the optical pressure between two planar surfaces.

PubMed

Hassanzadeh, Abdollah; Azami, Darya

2015-12-28

To enhance the optical pressure on a thin dielectric sample, a resonance structure using graphene layers coated over a metal film on a high index prism sputtered with MgF2 was theoretically analyzed. The number of graphene layers and the thicknesses of metal and MgF2 films were optimized to achieve the highest optical pressure on the sample. Effects of three different types of metals on the optical pressure were investigated numerically. In addition, simulations were carried out for samples with various thicknesses. Our numerical results show that the optical pressure increased by more than five orders of magnitude compared to the conventional metal-film-base resonance structure. The highest optical pressure was obtained for 10 layers of graphene deposited on 29-nm thick Au film and 650 nm thickness of MgF2 at 633nm wavelength, The proposed graphene based resonance structure can open new possibilities for optical tweezers, nanomechnical devices and surface plasmon based sensing and imaging techniques.

Optimal Resonant Band Demodulation Based on an Improved Correlated Kurtosis and Its Application in Bearing Fault Diagnosis

PubMed Central

Chen, Xianglong; Zhang, Bingzhi; Feng, Fuzhou; Jiang, Pengcheng

2017-01-01

The kurtosis-based indexes are usually used to identify the optimal resonant frequency band. However, kurtosis can only describe the strength of transient impulses, which cannot differentiate impulse noises and repetitive transient impulses cyclically generated in bearing vibration signals. As a result, it may lead to inaccurate results in identifying resonant frequency bands, in demodulating fault features and hence in fault diagnosis. In view of those drawbacks, this manuscript redefines the correlated kurtosis based on kurtosis and auto-correlative function, puts forward an improved correlated kurtosis based on squared envelope spectrum of bearing vibration signals. Meanwhile, this manuscript proposes an optimal resonant band demodulation method, which can adaptively determine the optimal resonant frequency band and accurately demodulate transient fault features of rolling bearings, by combining the complex Morlet wavelet filter and the Particle Swarm Optimization algorithm. Analysis of both simulation data and experimental data reveal that the improved correlated kurtosis can effectively remedy the drawbacks of kurtosis-based indexes and the proposed optimal resonant band demodulation is more accurate in identifying the optimal central frequencies and bandwidth of resonant bands. Improved fault diagnosis results in experiment verified the validity and advantage of the proposed method over the traditional kurtosis-based indexes. PMID:28208820

Helium gas purity monitor based on low frequency acoustic resonance

NASA Astrophysics Data System (ADS)

Kasthurirengan, S.; Jacob, S.; Karunanithi, R.; Karthikeyan, A.

1996-05-01

Monitoring gas purity is an important aspect of gas recovery stations where air is usually one of the major impurities. Purity monitors of Katherometric type are commercially available for this purpose. Alternatively, we discuss here a helium gas purity monitor based on acoustic resonance of a cavity at audio frequencies. It measures the purity by monitoring the resonant frequency of a cylindrical cavity filled with the gas under test and excited by conventional telephone transducers fixed at the ends. The use of the latter simplifies the design considerably. The paper discusses the details of the resonant cavity and the electronic circuit along with temperature compensation. The unit has been calibrated with helium gas of known purities. The unit has a response time of the order of 10 minutes and measures the gas purity to an accuracy of 0.02%. The unit has been installed in our helium recovery system and is found to perform satisfactorily.

Macromolecular and Dendrimer Based Magnetic Resonance Contrast Agents

PubMed Central

Bumb, Ambika; Brechbiel, Martin W.; Choyke, Peter

2010-01-01

Magnetic resonance imaging (MRI) is a powerful imaging modality that can provide an assessment of function or molecular expression in tandem with anatomic detail. Over the last 20–25 years, a number of gadolinium based MR contrast agents have been developed to enhance signal by altering proton relaxation properties. This review explores a range of these agents from small molecule chelates, such as Gd-DTPA and Gd-DOTA, to macromolecular structures composed of albumin, polylysine, polysaccharides (dextran, inulin, starch), poly(ethylene glycol), copolymers of cystamine and cystine with GD-DTPA, and various dendritic structures based on polyamidoamine and polylysine (Gadomers). The synthesis, structure, biodistribution and targeting of dendrimer-based MR contrast agents are also discussed. PMID:20590365

Magnetic resonance imaging based clinical research in Alzheimer's disease.

PubMed

Fayed, Nicolás; Modrego, Pedro J; Salinas, Gulillermo Rojas; Gazulla, José

2012-01-01

Alzheimer's disease (AD) is the most common cause of dementia in elderly people in western countries. However important goals are unmet in the issue of early diagnosis and the development of new drugs for treatment. Magnetic resonance imaging (MRI) and volumetry of the medial temporal lobe structures are useful tools for diagnosis. Positron emission tomography is one of the most sensitive tests for making an early diagnosis of AD but the cost and limited availability are important caveats for its utilization. The importance of magnetic resonance techniques has increased gradually to the extent that most clinical works based on AD use these techniques as the main aid to diagnosis. However, the accuracy of structural MRI as biomarker of early AD generally reaches an accuracy of 80%, so additional biomarkers should be used to improve predictions. Other structural MRI (diffusion weighted, diffusion-tensor MRI) and functional MRI have also added interesting contribution to the understanding of the pathophysiology of AD. Magnetic resonance spectroscopy has proven useful to monitor progression and response to treatment in AD, as well as a biomarker of early AD in mild cognitive impairment.

Nanoscale welding aerosol sensing based on whispering gallery modes in a cylindrical silica resonator.

PubMed

Lee, Aram; Mills, Thomas; Xu, Yong

2015-03-23

We report an experimental technique where one uses a standard silica fiber as a cylindrical whispering gallery mode (WGM) resonator to sense airborne nanoscale aerosols produced by electric arc welding. We find that the accumulation of aerosols on the resonator surface induces a measurable red-shift in resonance frequency, and establish an empirical relation that links the magnitude of resonance shift with the amount of aerosol deposition. The WGM quality factors, by contrast, do not decrease significantly, even for samples with a large percentage of surface area covered by aerosols. Our experimental results are discussed and compared with existing literature on WGM-based nanoparticle sensing.

Terahertz response of fractal meta-atoms based on concentric rectangular square resonators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Zhiqiang; Zhao, Zhenyu, E-mail: zyzhao@shnu.edu.cn; Shi, Wangzhou

We investigate the terahertz electromagnetic responses of fractal meta-atoms (MAs) induced by different mode coupling mechanisms. Two types of MAs based on concentric rectangular square (CRS) resonators are presented: independent CRS (I-CRS) and junctional-CRS (J-CRS). In I-CRS, each resonator works as an independent dipole so as to result in the multiple resonance modes when the fractal level is above 1. In J-CRS, however, the generated layer is rotated by π/2 radius to the adjacent CRS in one MA. The multiple resonance modes are coupled into a single mode resonance. The fractal level increasing induces resonance modes redshift in I-CRS whilemore » blueshift in J-CRS. When the fractal level is below 4, the mode Q factor of J-CRS is in between the two modes of I-CRS; when the fractal level is 4 or above, the mode Q factor of J-CRS exceeds the two modes of I-CRS. Furthermore, the modulation depth (MD) decreases in I-CRS while it increases in J-CRS with the increase in fractal levels. The surface currents analysis reveals that the capacitive coupling of modes in I-CRS results in the modes redshift, while the conductive coupling of modes in J-CRS induces the mode blueshift. A high Q mode with large MD can be achieved via conductive coupling between the resonators of different scales in a fractal MA.« less

Design of Multi-Resonant Cavities Based on Metal-Coated Dielectric Nanocylinders

NASA Astrophysics Data System (ADS)

Dong, Junyuan; Yu, Guanxia; Fu, Jingjing; Luo, Min; Du, Wenwen

2018-06-01

In this paper, the light scattering properties for multiple silver-coated dielectric nanocylinders with the symmetrical distribution were investigated. Based on the transfer matrix method, we derive the general transmission and reflection coefficient matrices for multiple dielectric nanocylinders. When the incident light frequencies are less than the plasma frequencies, the surface plasmons (SPs) appear in the interface between the silver and dielectrics. Numerical simulations show that there are three peaks of absorption cross-section (ACS) in the relationship between the ACS and the frequencies of the incident light, when the distance between the silver-coated dielectric nanocylinders is chosen properly. These SPs resonance peaks are characterised as resonances intrinsic to the cylindrically periodic system corresponding to different inner cavity structures. These multi-resonant cavities may have potential applications in integrated devices, optical sensors and optical storage devices.

Directly q-switched high power resonator based on XLMA-fibers

NASA Astrophysics Data System (ADS)

Giesberts, M.; Fitzau, O.; Hoffmann, H.-D.; Lange, R.; Bachert, C.; Krause, V.

2018-02-01

In this paper we present a simple approach to achieving nanosecond pulses from a directly q-switched high-power resonator based on extra-large mode area (XLMA) fibers with a beam quality factor M2 < 15. An average output power of > 500 W has been demonstrated for repetition frequencies between 50-100 kHz. The resonator consists of a single fiber q-switched with soldered Pockels-cells which exhibit a very high contrast ratio leading to output pulses down to about 10 ns and peak powers up to > 250 kW at 1064 nm wavelength. By using this design instead of a fiber MOPA setup, a cost-effective and less complex system could be implemented.

[Gadolinium-based contrast agents for magnetic resonance imaging].

PubMed

Carrasco Muñoz, S; Calles Blanco, C; Marcin, Javier; Fernández Álvarez, C; Lafuente Martínez, J

2014-06-01

Gadolinium-based contrast agents are increasingly being used in magnetic resonance imaging. These agents can improve the contrast in images and provide information about function and metabolism, increasing both sensitivity and specificity. We describe the gadolinium-based contrast agents that have been approved for clinical use, detailing their main characteristics based on their chemical structure, stability, and safety. In general terms, these compounds are safe. Nevertheless, adverse reactions, the possibility of nephrotoxicity from these compounds, and the possibility of developing nephrogenic systemic fibrosis will be covered in this article. Lastly, the article will discuss the current guidelines, recommendations, and contraindications for their clinical use, including the management of pregnant and breast-feeding patients. Copyright © 2014 SERAM. Published by Elsevier Espana. All rights reserved.

An Effective Electrical Resonance-Based Method to Detect Delamination in Thermal Barrier Coating

NASA Astrophysics Data System (ADS)

Kim, Jong Min; Park, Jae-Ha; Lee, Ho Girl; Kim, Hak-Joon; Song, Sung-Jin; Seok, Chang-Sung; Lee, Young-Ze

2017-12-01

This research proposes a simple yet highly sensitive method based on electrical resonance of an eddy-current probe to detect delamination of thermal barrier coating (TBC). This method can directly measure the mechanical characteristics of TBC compared to conventional ultrasonic testing and infrared thermography methods. The electrical resonance-based method can detect the delamination of TBC from the metallic bond coat by shifting the electrical impedance of eddy current testing (ECT) probe coupling with degraded TBC, and, due to this shift, the resonant frequencies near the peak impedance of ECT probe revealed high sensitivity to the delamination. In order to verify the performance of the proposed method, a simple experiment is performed with degraded TBC specimens by thermal cyclic exposure. Consequently, the delamination with growth of thermally grown oxide in a TBC system is experimentally identified. Additionally, the results are in good agreement with the results obtained from ultrasonic C-scanning.

An Effective Electrical Resonance-Based Method to Detect Delamination in Thermal Barrier Coating

NASA Astrophysics Data System (ADS)

Kim, Jong Min; Park, Jae-Ha; Lee, Ho Girl; Kim, Hak-Joon; Song, Sung-Jin; Seok, Chang-Sung; Lee, Young-Ze

2018-02-01

This research proposes a simple yet highly sensitive method based on electrical resonance of an eddy-current probe to detect delamination of thermal barrier coating (TBC). This method can directly measure the mechanical characteristics of TBC compared to conventional ultrasonic testing and infrared thermography methods. The electrical resonance-based method can detect the delamination of TBC from the metallic bond coat by shifting the electrical impedance of eddy current testing (ECT) probe coupling with degraded TBC, and, due to this shift, the resonant frequencies near the peak impedance of ECT probe revealed high sensitivity to the delamination. In order to verify the performance of the proposed method, a simple experiment is performed with degraded TBC specimens by thermal cyclic exposure. Consequently, the delamination with growth of thermally grown oxide in a TBC system is experimentally identified. Additionally, the results are in good agreement with the results obtained from ultrasonic C-scanning.

Nematic fluctuations and resonance in iron-based superconductors

NASA Astrophysics Data System (ADS)

Gallais, Yann

The spontaneous appearance of nematicity, a state of matter that breaks rotation but not translation symmetry, is ubiquitous in many iron based superconductors (Fe SC), and has relevance for the cuprates as well. Here I will review recent electronic Raman scattering experiments which report the presence of critical nematic fluctuations in the charge channel in the tetragonal phase of several Fe SC systems. In electron doped Co-BaFe2As2 (Co-Ba122), these fluctuations extend over most of the superconducting dome. Their associated nematic susceptibility shows Curie-Weiss behavior, and its doping dependence suggests the presence of a nematic quantum critical point near optimal TC Similar nematic fluctuations are also observed in FeSe despite the absence of magnetic order, raising the question of the link between nematicity and magnetism in Fe SC. In FeSe I will further contrast the evolution of nematic fluctuations under isoelectronic S substitution and hydrostatic pressures up to 8 GPa, with only the former showing evidence for a nematic quantum critical point. In the superconducting state of Co-Ba122, I will show that a resonance emerges in the Raman spectra near the nematic quantum critical point. This nematic resonance is a clear fingerprint of the coupling between nematic fluctuations and Bogoliubov quasiparticles, and can be thought as the nematic counterpart of the spin resonance observed in neutron scattering experiments. Support from Agence Nationale de la Recherche via ANR Grant ''Pnictides'' is acknowledged.

Fundamentals of metasurface lasers based on resonant dark states

NASA Astrophysics Data System (ADS)

Droulias, Sotiris; Jain, Aditya; Koschny, Thomas; Soukoulis, Costas M.

2017-10-01

Recently, our group proposed a metamaterial laser design based on explicitly coupled dark resonant states in low-loss dielectrics, which conceptually separates the gain-coupled resonant photonic state responsible for macroscopic stimulated emission from the coupling to specific free-space propagating modes, allowing independent adjustment of the lasing state and its coherent radiation output. Due to this functionality, it is now possible to make lasers that can overcome the trade-off between system dimensions and Q factor, especially for surface emitting lasers with deeply subwavelength thickness. Here, we give a detailed discussion of the key functionality and benefits of this design, such as radiation damping tunability, directionality, subwavelength integration, and simple layer-by-layer fabrication. We examine in detail the fundamental design tradeoffs that establish the principle of operation and must be taken into account and give guidance for realistic implementations.

Graphene-based multilayer resonance structure to enhance the optical pressure on a Mie particle

NASA Astrophysics Data System (ADS)

Hassanzadeh, Abdollah; Mohammadnezhad, Mohammadbagher

2016-04-01

We theoretically investigate the optical force exerted on a Mie dielectric particle in the evanescent field of a graphene-based resonance multilayer structure using the arbitrary beam theory and the theory of multilayer films. The resonance structure consists of several thin films including a dielectric film (MgF2), a metal film (silver or gold), and several graphene layers which are located on a prism base. The effects of the metal film thickness and the number of graphene layers on the optical force are numerically investigated. The thickness of the metal layer and the number of graphene layers are optimized to reach the highest optical force. The numerical results show that an optimized composition of graphene and gold leads to a higher optical force compared to that of the graphene and silver. The optical force was enhanced resonantly by four orders of magnitude for the resonance structure containing graphene and a gold film and by three orders of magnitude for the structure containing graphene and a silver film compared to other similar resonance structures. We hope that the results presented in this paper can provide an excellent means of improving the optical manipulation of particles and enable the provision of effective optical tweezers, micromotors, and microaccelelators.

Image Guided Focal Therapy for Magnetic Resonance Imaging Visible Prostate Cancer: Defining a 3-Dimensional Treatment Margin Based on Magnetic Resonance Imaging Histology Co-Registration Analysis.

PubMed

Le Nobin, Julien; Rosenkrantz, Andrew B; Villers, Arnauld; Orczyk, Clément; Deng, Fang-Ming; Melamed, Jonathan; Mikheev, Artem; Rusinek, Henry; Taneja, Samir S

2015-08-01

We compared prostate tumor boundaries on magnetic resonance imaging and radical prostatectomy histological assessment using detailed software assisted co-registration to define an optimal treatment margin for achieving complete tumor destruction during image guided focal ablation. Included in study were 33 patients who underwent 3 Tesla magnetic resonance imaging before radical prostatectomy. A radiologist traced lesion borders on magnetic resonance imaging and assigned a suspicion score of 2 to 5. Three-dimensional reconstructions were created from high resolution digitalized slides of radical prostatectomy specimens and co-registered to imaging using advanced software. Tumors were compared between histology and imaging by the Hausdorff distance and stratified by the magnetic resonance imaging suspicion score, Gleason score and lesion diameter. Cylindrical volume estimates of treatment effects were used to define the optimal treatment margin. Three-dimensional software based registration with magnetic resonance imaging was done in 46 histologically confirmed cancers. Imaging underestimated tumor size with a maximal discrepancy between imaging and histological boundaries for a given tumor of an average ± SD of 1.99 ± 3.1 mm, representing 18.5% of the diameter on imaging. Boundary underestimation was larger for lesions with an imaging suspicion score 4 or greater (mean 3.49 ± 2.1 mm, p <0.001) and a Gleason score of 7 or greater (mean 2.48 ± 2.8 mm, p = 0.035). A simulated cylindrical treatment volume based on the imaging boundary missed an average 14.8% of tumor volume compared to that based on the histological boundary. A simulated treatment volume based on a 9 mm treatment margin achieved complete histological tumor destruction in 100% of patients. Magnetic resonance imaging underestimates histologically determined tumor boundaries, especially for lesions with a high imaging suspicion score and a high Gleason score. A 9 mm treatment margin around a lesion

Self-oscillations in field emission nanowire mechanical resonators: a nanometric dc-ac conversion.

PubMed

Ayari, Anthony; Vincent, Pascal; Perisanu, Sorin; Choueib, May; Gouttenoire, Vincent; Bechelany, Mikhael; Cornu, David; Purcell, Stephen T

2007-08-01

We report the observation of self-oscillations in a bottom-up nanoelectromechanical system (NEMS) during field emission driven by a constant applied voltage. An electromechanical model is explored that explains the phenomenon and that can be directly used to develop integrated devices. In this first study, we have already achieved approximately 50% dc/ac (direct to alternating current) conversion. Electrical self-oscillations in NEMS open up a new path for the development of high-speed, autonomous nanoresonators and signal generators and show that field emission (FE) is a powerful tool for building new nanocomponents.

A comprehensive review of lossy mode resonance-based fiber optic sensors

NASA Astrophysics Data System (ADS)

Wang, Qi; Zhao, Wan-Ming

2018-01-01

This review paper presents the achievements and present developments in lossy mode resonances-based optical fiber sensors in different sensing field, such as physical, chemical and biological, and briefly look forward to its future development trend in the eyes of the author. Lossy mode resonances (LMR) is a relatively new physical optics phenomenon put forward in recent years. Fiber sensors utilizing LMR offered a new way to improve the sensing capability. LMR fiber sensors have diverse structures such as D-shaped, cladding-off, fiber tip, U-shaped and tapered fiber structures. Major applications of LMR sensors include refraction sensors and biosensors. LMR-based fiber sensors have attracted considerable research and development interest, because of their distinct advantages such as high sensitivity and label-free measurement. This kind of sensor is also of academic interest and many novel and great ideas are continuously developed.

Design of a dielectric resonator receive array at 7 Tesla using detunable ceramic resonators

NASA Astrophysics Data System (ADS)

Ruytenberg, Thomas; Webb, Andrew G.

2017-11-01

Ceramic-based dielectric resonators can be used for high frequency magnetic resonance imaging and microscopy. When used as elements in a transmit array, the intrinsically low inter-element coupling allows flexibility in designing different geometric arrangements for different regions-of-interest. However, without being able to detune such resonators, they cannot be used as elements in a receive-only array. Here, we propose and implement a method, based on mode-disruption, for detuning ceramic-based dielectric resonators to enable them to be used as receive-only elements.

Resonant Magnetic Field Sensors Based On MEMS Technology.

PubMed

Herrera-May, Agustín L; Aguilera-Cortés, Luz A; García-Ramírez, Pedro J; Manjarrez, Elías

2009-01-01

Microelectromechanical systems (MEMS) technology allows the integration of magnetic field sensors with electronic components, which presents important advantages such as small size, light weight, minimum power consumption, low cost, better sensitivity and high resolution. We present a discussion and review of resonant magnetic field sensors based on MEMS technology. In practice, these sensors exploit the Lorentz force in order to detect external magnetic fields through the displacement of resonant structures, which are measured with optical, capacitive, and piezoresistive sensing techniques. From these, the optical sensing presents immunity to electromagnetic interference (EMI) and reduces the read-out electronic complexity. Moreover, piezoresistive sensing requires an easy fabrication process as well as a standard packaging. A description of the operation mechanisms, advantages and drawbacks of each sensor is considered. MEMS magnetic field sensors are a potential alternative for numerous applications, including the automotive industry, military, medical, telecommunications, oceanographic, spatial, and environment science. In addition, future markets will need the development of several sensors on a single chip for measuring different parameters such as the magnetic field, pressure, temperature and acceleration.

Resonant Magnetic Field Sensors Based On MEMS Technology

PubMed Central

Herrera-May, Agustín L.; Aguilera-Cortés, Luz A.; García-Ramírez, Pedro J.; Manjarrez, Elías

2009-01-01

Microelectromechanical systems (MEMS) technology allows the integration of magnetic field sensors with electronic components, which presents important advantages such as small size, light weight, minimum power consumption, low cost, better sensitivity and high resolution. We present a discussion and review of resonant magnetic field sensors based on MEMS technology. In practice, these sensors exploit the Lorentz force in order to detect external magnetic fields through the displacement of resonant structures, which are measured with optical, capacitive, and piezoresistive sensing techniques. From these, the optical sensing presents immunity to electromagnetic interference (EMI) and reduces the read-out electronic complexity. Moreover, piezoresistive sensing requires an easy fabrication process as well as a standard packaging. A description of the operation mechanisms, advantages and drawbacks of each sensor is considered. MEMS magnetic field sensors are a potential alternative for numerous applications, including the automotive industry, military, medical, telecommunications, oceanographic, spatial, and environment science. In addition, future markets will need the development of several sensors on a single chip for measuring different parameters such as the magnetic field, pressure, temperature and acceleration. PMID:22408480

Minimalist-design, high-functionality, micro-ring resonator-based optical filter with narrow linewidth and low group delay using Looped Back Over- and Under-coupled Resonator (LOBOUR)

NASA Astrophysics Data System (ADS)

Ye, Bo; Dingel, Benjamin B.; Cui, Weili

2013-01-01

We present a minimalist design but high functionality micro-ring resonator based optical filter with narrow linewidth and low group delay using a novel design we called LOBOUR for LOoped-Back Over- and Under- Coupled Resonator (LOBOUR). The characteristics of both narrow linewidth and low group delay (low chromatic dispersion) generally do not come together especially when using a single ring resonator. The Cascaded Over- and Under-Coupled Resonator (COUR) design was able to achieve this goal but introduced many practical fabrication issues. Here, we present an alternative design to COUR which uses only one ring resonator and without fabrication and manufacturing issues. It can achieve 50 dB extinction ratio and tens of ps performance. We also present important parameter selection mapping for LOBOUR.

Whispering gallery mode resonators based on radiation-sensitive materials

NASA Technical Reports Server (NTRS)

Savchenkov, Anatoliy (Inventor); Maleki, Lutfollah (Inventor); Ilchenko, Vladimir (Inventor); Handley, Timothy A. (Inventor)

2005-01-01

Whispering gallery mode (WGM) optical resonators formed of radiation-sensitive materials to allow for permanent tuning of their resonance frequencies in a controlled manner. Two WGM resonators may be cascaded to form a composite filter to produce a second order filter function where at least one WGM resonator is formed a radiation-sensitive material to allow for proper control in the overlap of the two filter functions.

Resonance Parameter Adjustment Based on Integral Experiments

DOE PAGES

Sobes, Vladimir; Leal, Luiz; Arbanas, Goran; ...

2016-06-02

Our project seeks to allow coupling of differential and integral data evaluation in a continuous-energy framework and to use the generalized linear least-squares (GLLS) methodology in the TSURFER module of the SCALE code package to update the parameters of a resolved resonance region evaluation. We recognize that the GLLS methodology in TSURFER is identical to the mathematical description of a Bayesian update in SAMMY, the SAMINT code was created to use the mathematical machinery of SAMMY to update resolved resonance parameters based on integral data. Traditionally, SAMMY used differential experimental data to adjust nuclear data parameters. Integral experimental data, suchmore » as in the International Criticality Safety Benchmark Experiments Project, remain a tool for validation of completed nuclear data evaluations. SAMINT extracts information from integral benchmarks to aid the nuclear data evaluation process. Later, integral data can be used to resolve any remaining ambiguity between differential data sets, highlight troublesome energy regions, determine key nuclear data parameters for integral benchmark calculations, and improve the nuclear data covariance matrix evaluation. Moreover, SAMINT is not intended to bias nuclear data toward specific integral experiments but should be used to supplement the evaluation of differential experimental data. Using GLLS ensures proper weight is given to the differential data.« less

Graphene enhanced surface plasmon resonance sensing based on Goos-Hänchen shift

NASA Astrophysics Data System (ADS)

Chen, Huifang; Tong, Jinguang; Wang, Yiqin; Jiang, Li

2018-03-01

A graphene/Ag structure is engineered as an enhanced platform for surface plasmon resonance sensing due to the high impermeability nature of graphene and the superior surface plasmon resonance performance of Ag. This structure is ultrasensitive to even tiny refractive index change of analytes based on Goos-Hänchen shift measurement compared to the traditional SPR sensor with bare Au film. The graphene/Ag configuration is consisted of five components, including BK7 glass slide, titanium thin film, silver thin film, two-dimensional graphene layers and biomolecular analyte layer. We have optimized the parameters of each layer and theoretically analyzed Goos-Hänchen shift of the plasmonic structure under surface plasmon resonance effect. The optimized graphene/Ag structure is monolayer graphene coated on Ag thin film with the thickness of 42 nm.

Fundamentals of metasurface lasers based on resonant dark states

DOE PAGES

Droulias, Sotiris; Jain, Aditya; Koschny, Thomas; ...

2017-10-30

Recently, our group proposed a metamaterial laser design based on explicitly coupled dark resonant states in low-loss dielectrics, which conceptually separates the gain-coupled resonant photonic state responsible for macroscopic stimulated emission from the coupling to specific free-space propagating modes, allowing independent adjustment of the lasing state and its coherent radiation output. Due to this functionality, it is now possible to make lasers that can overcome the trade-off between system dimensions and Q factor, especially for surface emitting lasers with deeply subwavelength thickness. In this paper, we give a detailed discussion of the key functionality and benefits of this design, suchmore » as radiation damping tunability, directionality, subwavelength integration, and simple layer-by-layer fabrication. Finally, we examine in detail the fundamental design tradeoffs that establish the principle of operation and must be taken into account and give guidance for realistic implementations.« less

Fano resonance in anodic aluminum oxide based photonic crystals.

PubMed

Shang, Guo Liang; Fei, Guang Tao; Zhang, Yao; Yan, Peng; Xu, Shao Hui; Ouyang, Hao Miao; Zhang, Li De

2014-01-08

Anodic aluminum oxide based photonic crystals with periodic porous structure have been prepared using voltage compensation method. The as-prepared sample showed an ultra-narrow photonic bandgap. Asymmetric line-shape profiles of the photonic bandgaps have been observed, which is attributed to Fano resonance between the photonic bandgap state of photonic crystal and continuum scattering state of porous structure. And the exhibited Fano resonance shows more clearly when the sample is saturated ethanol gas than air-filled. Further theoretical analysis by transfer matrix method verified these results. These findings provide a better understanding on the nature of photonic bandgaps of photonic crystals made up of porous materials, in which the porous structures not only exist as layers of effective-refractive-index material providing Bragg scattering, but also provide a continuum light scattering state to interact with Bragg scattering state to show an asymmetric line-shape profile.

High intersubband absorption in long-wave quantum well infrared photodetector based on waveguide resonance

NASA Astrophysics Data System (ADS)

Zheng, Yuanliao; Chen, Pingping; Ding, Jiayi; Yang, Heming; Nie, Xiaofei; Zhou, Xiaohao; Chen, Xiaoshuang; Lu, Wei

2018-06-01

A hybrid structure consisting of periodic gold stripes and an overlaying gold film has been proposed as the optical coupler of a long-wave quantum well infrared photodetector. Absorption spectra and field distributions of the structure at back-side normal incidence are calculated by the finite difference time-domain method. The results indicate that the intersubband absorption can be greatly enhanced based on the waveguide resonance as well as the surface plasmon polariton (SPP) mode. With the optimized structural parameters of the periodic gold stripes, the maximal intersubband absorption can exceed 80%, which is much higher than the SPP-enhanced intersubband absorption (<50%) and about 6 times the one of the standard device. The relationship between the structural parameters and the waveguide resonant wavelength is derived. Other advantages of the efficient optical coupling based on waveguide resonance are also discussed.

Diode laser based resonance ionization mass spectrometric measurement of strontium-90

NASA Astrophysics Data System (ADS)

Bushaw, B. A.; Cannon, B. D.

1997-10-01

A diode laser based scheme for the isotopically selective excitation and ionization of strontium is presented. The double-resonance excitation 5s 21S 0→5s5p 3P 1→5s6s 3S 1 is followed by photoionization at 488 nm. The isotope shifts and hyperfine structure in the resonance transitions have been accurately measured for the stable isotopes and 90Sr, with the measurement of the 90Sr shifts using sub-pg samples. Analytical tests, using graphite crucible atomization, demonstrated 90Sr detection limits of 0.8 fg and overall (optical+mass spectrometer) isotopic selectivity of >10 10 against stable strontium.

Analysis and development of fourth order LCLC resonant based capacitor charging power supply for pulse power applications.

PubMed

Naresh, P; Hitesh, C; Patel, A; Kolge, T; Sharma, Archana; Mittal, K C

2013-08-01

A fourth order (LCLC) resonant converter based capacitor charging power supply (CCPS) is designed and developed for pulse power applications. Resonant converters are preferred t utilize soft switching techniques such as zero current switching (ZCS) and zero voltage switching (ZVS). An attempt has been made to overcome the disadvantages in 2nd and 3rd resonant converter topologies; hence a fourth order resonant topology is used in this paper for CCPS application. In this paper a novel fourth order LCLC based resonant converter has been explored and mathematical analysis carried out to calculate load independent constant current. This topology provides load independent constant current at switching frequency (fs) equal to resonant frequency (fr). By changing switching condition (on time and dead time) this topology has both soft switching techniques such as ZCS and ZVS for better switching action to improve the converter efficiency. This novel technique has special features such as low peak current through switches, DC blocking for transformer, utilizing transformer leakage inductance as resonant component. A prototype has been developed and tested successfully to charge a 100 μF capacitor to 200 V.

Resonant characteristics and sensitivity dependency on the contact surface in QCM-micropillar-based system of coupled resonator sensors

NASA Astrophysics Data System (ADS)

Kashan, M. A. M.; Kalavally, V.; Lee, H. W.; Ramakrishnan, N.

2016-05-01

We report the characteristics and sensitivity dependence over the contact surface in coupled resonating sensors (CRSs) made of high aspect ratio resonant micropillars attached to a quartz crystal microbalance (QCM). Through experiments and simulation, we observed that when the pillars of resonant heights were placed in maximum displacement regions the resonance frequency of the QCM increased following the coupled resonance characteristics, as the pillar offered elastic loading to the QCM surface. However, the same pillars when placed in relatively lower displacement regions, in spite of their resonant dimension, offered inertial loading and resulted in a decrease in QCM resonance frequency, as the displacement amplitude was insufficient to couple the vibrations from the QCM to the pillars. Accordingly, we discovered that the coupled resonance characteristics not only depend on the resonant structure dimensions but also on the contact regions in the acoustic device. Further analysis revealed that acoustic pressure at the contact surface also influences the resonance frequency characteristics and sensitivity of the CRS. To demonstrate the significance of the present finding for sensing applications, humidity sensing is considered as the example measurand. When a sensing medium made of resonant SU-8 pillars was placed in a maximum displacement region on a QCM surface, the sensitivity increased by 14 times in comparison to a resonant sensing medium placed in a lower displacement region of a QCM surface.

Tunable plasmonic dual wavelength multi/demultiplexer based on graphene sheets and cylindrical resonator

NASA Astrophysics Data System (ADS)

Asgari, Somayyeh; Granpayeh, Nosrat

2017-06-01

Two parallel graphene sheet waveguides and a graphene cylindrical resonator between them is proposed, analyzed, and simulated numerically by using the finite-difference time-domain method. One end of each graphene waveguide is the input and output port. The resonance and the prominent mid-infrared band-pass filtering effect are achieved. The transmittance spectrum is tuned by varying the radius of the graphene cylindrical resonator, the dielectric inside it, and also the chemical potential of graphene utilizing gate voltage. Simulation results are in good agreement with theoretical calculations. As an application, a multi/demultiplexer is proposed and analyzed. Our studies demonstrate that graphene based ultra-compact, nano-scale devices can be designed for optical processing and photonic integrated devices.

Monolithic Micromachined Quartz Resonator based Infrared Focal Plane Arrays

DTIC Science & Technology

2012-05-05

following categories: PaperReceived Ping Kao, Srinivas Tadigadapa. Micromachined quartz resonator based infrared detector array, Sensors and...0. doi: 10.1088/0957-0233/20/12/124007 2012/05/08 19:47:37 6 S Tadigadapa, K Mateti. Piezoelectric MEMS sensors : state-of-the-art and perspectives...Ping Kao, David L. Allara, Srinivas Tadigadapa. Study of Adsorption of Globular Proteins on Hydrophobic Surfaces, IEEE Sensors Journal, (11 2011): 0

Unidirectional reflectionless propagation in non-Hermitian metamaterial based on phase coupling between two resonators

NASA Astrophysics Data System (ADS)

Yin, Hongda; Bai, Ruiping; Gu, Xintong; Zhang, Cong; Gu, Guang Rui; Zhang, Ying Qiao; Jin, Xing Ri; Lee, YoungPak

2018-05-01

Unidirectional reflectionless propagation in a non-Hermitian metamaterial is obtained based on phase coupling between two resonators. The unidirectional reflectionless propagation can be obtained at exceptional point by adjusting polarization angle θ and distance d between two resonators. Moreover, coherent prefect absorptions are obtained near exceptional point with the high absorbance of ∼0.99 and high quality factor of ∼83.

Spectral properties of all-active InP-based microring resonator devices

NASA Astrophysics Data System (ADS)

Kapsalis, A.; Alexandropoulos, D.; Mikroulis, S.; Simos, H.; Stamataki, I.; Syvridis, D.; Hamacher, M.; Troppenz, U.; Heidrich, H.

2006-02-01

Microring resonators are excellent candidates for very large scale photonic integration due to their compactness, and fabrication simplicity. Moreover a wide range of all-optical signal processing functions can be realized due to the resonance effect. Possible applications include filtering, add/drop of optical beams and power switching, as well as more complex procedures including multiplexing, wavelength conversion, and logic operations. All-active ring components based in InGaAsP/InP are possible candidates for laser sources, lossless filters, wavelength converters, etc. Our work is based on measurement, characterization and proposal of possible exploitation of such devices in a variety of applications. We investigate the spectral characteristics of multi-quantum well InGaAsP(λ=1.55μm)/InP microring structures of various ring diameters and different configurations including racetracks with one or two bus waveguides and MMI couplers. The latter configuration has recently exhibited the possibility to obtain tunable active filters as well as tunable laser sources based on all-active ring-bus-coupler structures. In the case of tunable lasers single mode operation has been achieved by obtaining sufficiently high side mode suppression ratio. The tuning capability is attributed to a coupled cavities effect, resembling the case of multi-section DBR lasers. However, in contrast to the latter, the fabrication of microring resonators is considered an easier task, due to a single step growth procedure, although further investigation must be carried out in order to achieve wide range tunability. Detailed mappings of achievable wavelengths are produced for a wide range of injection current values.

EDITORIAL: World Year of Physics 2005 Focus on Photoemission and Electronic Structure

NASA Astrophysics Data System (ADS)

2005-04-01

Around the year 1500, Leonardo da Vinci designed the first mechanical calculator connecting a number of toothed wheels for simple adding operations. Since then, mechanical systems have become a major part of the later industrial revolutions with an abundance of machines in our everyday lives. Only with the advent of semiconductor electronics, however, did microstructuring techniques become available to realize mechanical systems with dimensions below 100 microns. With most recent structure sizes now reaching the limit of a few nanometres, suspended nanostructures that couple mechanical with electronic motion have been constructed. Moreover, novel lithographic techniques have enabled the investigation of transport across hybrid structures such as. suspended carbon nanotubes or flexible molecular bridges connected to mesoscopic leads. In this invited focus issue of New Journal of Physics some of the leading experts in the field of nano-electromechanical systems (NEMS) describe the latest status and trends, from both an experimental and a theoretical perspective. A multitude of applications for NEMS are now within reach, ranging from high-frequency filters and switches in signal processing circuits, to ultra-sensitive sensors. In particular the development of mass sensors and scanning probe microscopy will be spurred by nano-mechanical systems. Considering that mechanical resonance frequencies of 1 GHz and more have already been achieved, these devices will be extremely sensitive and will offer high data acquisition rates. On a fundamental level NEMS enable the investigation of electron-phonon coupling in the absolute limit via, for example, single electrons interacting with single (quantized) phonons, the study of single electrons being shuttled via mechanical motion, and the manipulation of single molecules with nano-mechanical tweezers. The future for NEMS research looks certain to be exciting - we can expect it to help us build detectors of virtually any kind

Modelling of Piezothermoelastic Beam with Fractional Order Derivative

NASA Astrophysics Data System (ADS)

Kumar, Rajneesh; Sharma, Poonam

2016-04-01

This paper deals with the study of transverse vibrations in piezothermoelastic beam resonators with fractional order derivative. The fractional order theory of thermoelasticity developed by Sherief et al. [1] has been used to study the problem. The expressions for frequency shift and damping factor are derived for a thermo micro-electromechanical (MEM) and thermo nano-electromechanical (NEM) beam resonators clamped on one side and free on another. The effect of fractional order derivative on the derived expressions is observed analytically and shown graphically in the case of Lead Zirconate Titanate (PZT)-5A material. For α = 1, our results agree with those that are obtained by Grover and Sharma [20] and other particular cases of interest are also discussed.

Correlation Between Magnetic Resonance Imaging-Based Evaluation of Extramural Vascular Invasion and Prognostic Parameters of T3 Stage Rectal Cancer.

PubMed

Yu, Jing; Huang, Dong-Ya; Xu, Hui-Xin; Li, Yang; Xu, Qing

2016-01-01

The aim of this study was to analyze the correlation between magnetic resonance imaging-based extramural vascular invasion (EMVI) and the prognostic clinical and histological parameters of stage T3 rectal cancers. Eighty-six patients with T3 stage rectal cancer who received surgical resection without neoadjuvant therapy were included. Magnetic resonance imaging-based EMVI scores were determined. Correlations between the scores and pretreatment carcinoembryonic antigen levels, tumor differentiation grade, nodal stage, and vascular endothelial growth factor expression were analyzed using Spearman rank coefficient analysis. Magnetic resonance imaging-based EMVI scores were statistically different (P = 0.001) between histological nodal stages (N0 vs N1 vs N2). Correlations were found between magnetic resonance imaging-based EMVI scores and tumor histological grade (rs = 0.227, P = 0.035), histological nodal stage (rs = 0.524, P < 0.001), and vascular endothelial growth factor expression (rs = 0.422; P = 0.016). Magnetic resonance imaging-based EMVI score is correlated with prognostic parameters of T3 stage rectal cancers and has the potential to become an imaging biomarker of tumor aggressiveness. Magnetic resonance imaging-based EMVI may be useful in helping the multidisciplinary team to stratify T3 rectal cancer patients for neoadjuvant therapies.

Optically-Switched Resonant Tunneling Diodes for Space-Based Optical Communication Applications

NASA Technical Reports Server (NTRS)

Moise, T. S.; Kao, Y. -C.; Jovanovic, D.; Sotirelis, P.

1995-01-01

We are developing a new type of digital photo-receiver that has the potential to perform high speed optical-to-electronic conversion with a factor of 10 reduction in component count and power dissipation. In this paper, we describe the room-temperature photo-induced switching of this InP-based device which consists of an InGaAs/AlAs resonant tunneling diode integrated with an InGaAs absorber layer. When illuminated at an irradiance of greater than 5 Wcm(exp -2) using 1.3 micromillimeter radiation, the resonant tunneling diode switches from a high-conductance to a low-conductance electrical state and exhibits a voltage swing of up to 800 mV.

Microstrip resonators for electron paramagnetic resonance experiments

NASA Astrophysics Data System (ADS)

Torrezan, A. C.; Mayer Alegre, T. P.; Medeiros-Ribeiro, G.

2009-07-01

In this article we evaluate the performance of an electron paramagnetic resonance (EPR) setup using a microstrip resonator (MR). The design and characterization of the resonator are described and parameters of importance to EPR and spin manipulation are examined, including cavity quality factor, filling factor, and microwave magnetic field in the sample region. Simulated microwave electric and magnetic field distributions in the resonator are also presented and compared with qualitative measurements of the field distribution obtained by a perturbation technique. Based on EPR experiments carried out with a standard marker at room temperature and a MR resonating at 8.17 GHz, the minimum detectable number of spins was found to be 5×1010 spins/GHz1/2 despite the low MR unloaded quality factor Q0=60. The functionality of the EPR setup was further evaluated at low temperature, where the spin resonance of Cr dopants present in a GaAs wafer was detected at 2.3 K. The design and characterization of a more versatile MR targeting an improved EPR sensitivity and featuring an integrated biasing circuit for the study of samples that require an electrical contact are also discussed.

Microstrip resonators for electron paramagnetic resonance experiments.

PubMed

Torrezan, A C; Mayer Alegre, T P; Medeiros-Ribeiro, G

2009-07-01

In this article we evaluate the performance of an electron paramagnetic resonance (EPR) setup using a microstrip resonator (MR). The design and characterization of the resonator are described and parameters of importance to EPR and spin manipulation are examined, including cavity quality factor, filling factor, and microwave magnetic field in the sample region. Simulated microwave electric and magnetic field distributions in the resonator are also presented and compared with qualitative measurements of the field distribution obtained by a perturbation technique. Based on EPR experiments carried out with a standard marker at room temperature and a MR resonating at 8.17 GHz, the minimum detectable number of spins was found to be 5 x 10(10) spins/GHz(1/2) despite the low MR unloaded quality factor Q0=60. The functionality of the EPR setup was further evaluated at low temperature, where the spin resonance of Cr dopants present in a GaAs wafer was detected at 2.3 K. The design and characterization of a more versatile MR targeting an improved EPR sensitivity and featuring an integrated biasing circuit for the study of samples that require an electrical contact are also discussed.

Three-wavelength multiplexer/demultiplexer based on photonic crystal ring resonator and cavities

NASA Astrophysics Data System (ADS)

Zhang, Jia; Xu, Xu-Ming; He, Ling-Juan

2011-12-01

We proposed a three-wavelength multiplexer/demultiplexer based on the characteristics of resonant coupling between photonic crystal ring resonator (PCRR) and cavity. The structure composed of one PCRR and three cavities. The numerical results obtained by the finite-different time-domain (FTDT) method show that it can realize the demultiplexing of three wavelengths, i.e. 1430nm, 1490nm and 1550nm only by modulating the radius of the cavities. The designed device not only has a compact size with 12μm×11μm but also a high efficiency, may have potential applications in the integrated optics fields.

A MEMS disk resonator-based band pass filter electrical equivalent circuit simulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sundaram, G. M.; Angira, Mahesh; Gupta, Navneet

In this paper, coupled beam bandpass Disk filter is designed for 1 MHz bandwidth. Filter electrical equivalent circuit simulation is performed using circuit simulators. Important filter parameters such as insertion loss, shape factor and Q factor aresetimated using coventorware simulation. Disk resonator based radial contour mode filter provides 1.5 MHz bandwidth and unloaded quality factor of resonator and filter as 233480, 21797 respectively. From the simulation result it’s found that insertion loss minimum is 151.49 dB, insertion loss maximum is 213.94 dB, and 40 dB shape factor is 4.17.

Resonant tunneling based graphene quantum dot memristors.

PubMed

Pan, Xuan; Skafidas, Efstratios

2016-12-08

In this paper, we model two-terminal all graphene quantum dot (GQD) based resistor-type memory devices (memristors). The resistive switching is achieved by resonant electron tunneling. We show that parallel GQDs can be used to create multi-state memory circuits. The number of states can be optimised with additional voltage sources, whilst the noise margin for each state can be controlled by appropriately choosing the branch resistance. A three-terminal GQD device configuration is also studied. The addition of an isolated gate terminal can be used to add further or modify the states of the memory device. The proposed devices provide a promising route towards volatile memory devices utilizing only atomically thin two-dimensional graphene.

Nuclear Magnetic Resonance Spectroscopy-Based Identification of Yeast.

PubMed

Himmelreich, Uwe; Sorrell, Tania C; Daniel, Heide-Marie

2017-01-01

Rapid and robust high-throughput identification of environmental, industrial, or clinical yeast isolates is important whenever relatively large numbers of samples need to be processed in a cost-efficient way. Nuclear magnetic resonance (NMR) spectroscopy generates complex data based on metabolite profiles, chemical composition and possibly on medium consumption, which can not only be used for the assessment of metabolic pathways but also for accurate identification of yeast down to the subspecies level. Initial results on NMR based yeast identification where comparable with conventional and DNA-based identification. Potential advantages of NMR spectroscopy in mycological laboratories include not only accurate identification but also the potential of automated sample delivery, automated analysis using computer-based methods, rapid turnaround time, high throughput, and low running costs.We describe here the sample preparation, data acquisition and analysis for NMR-based yeast identification. In addition, a roadmap for the development of classification strategies is given that will result in the acquisition of a database and analysis algorithms for yeast identification in different environments.

Design of a lithium niobate-on-insulator-based optical microring resonator for biosensing applications

NASA Astrophysics Data System (ADS)

Naznin, Shakila; Sher, Md. Sohel Mahmud

2016-08-01

A label-free optical microring resonator biosensor based on lithium niobate-on-insulator (LNOI) technology is designed and simulated for biosensing applications. Although silicon-on-insulator technology is quite mature over LNOI for fabricating more compact microring resonators, the latter is attractive for its excellent electro-optic, ferroelectric, piezoelectric, photoelastic, and nonlinear optic properties, which can offer a wide range of tuning facilities for sensing. To satisfy the requirement of high sensitivity in biosensing, the dual-microring resonator model is applied to design the proposed sensor. The transmission spectrum obtained from two-dimensional simulations based on finite-difference time-domain method demonstrates that the designed LNOI microring sensor consisting of a 10-μm outer ring and a 5-μm inner ring offers a sensitivity of ˜68 nm/refractive index unit (RIU) and a minimum detection limit of 10-2 RIU. Finally, the sensor's performance is simulated for glucose sensing, a biosensing application.

Amplitude quantification in contact-resonance-based voltage-modulated force spectroscopy

NASA Astrophysics Data System (ADS)

Bradler, Stephan; Schirmeisen, André; Roling, Bernhard

2017-08-01

Voltage-modulated force spectroscopy techniques, such as electrochemical strain microscopy and piezoresponse force microscopy, are powerful tools for characterizing electromechanical properties on the nanoscale. In order to correctly interpret the results, it is important to quantify the sample motion and to distinguish it from the electrostatic excitation of the cantilever resonance. Here, we use a detailed model to describe the cantilever dynamics in contact resonance measurements, and we compare the results with experimental values. We show how to estimate model parameters from experimental values and explain how they influence the sensitivity of the cantilever with respect to the excitation. We explain the origin of different crosstalk effects and how to identify them. We further show that different contributions to the measured signal can be distinguished by analyzing the correlation between the resonance frequency and the measured amplitude. We demonstrate this technique on two representative test samples: (i) ferroelectric periodically poled lithium niobate, and (ii) the Na+-ion conducting soda-lime float glass. We extend our analysis to higher cantilever bending modes and show that non-local electrostatic excitation is strongly reduced in higher bending modes due to the nodes in the lever shape. Based on our analyses, we present practical guidelines for quantitative imaging.

Effect of oscillator strength and intermediate resonance on the performance of resonant phonon-based terahertz quantum cascade lasers

NASA Astrophysics Data System (ADS)

Fathololoumi, S.; Dupont, E.; Wasilewski, Z. R.; Chan, C. W. I.; Razavipour, S. G.; Laframboise, S. R.; Huang, Shengxi; Hu, Q.; Ban, D.; Liu, H. C.

2013-03-01

We experimentally investigated the effect of oscillator strength (radiative transition diagonality) on the performance of resonant phonon-based terahertz quantum cascade lasers that have been optimized using a simplified density matrix formalism. Our results show that the maximum lasing temperature (Tmax) is roughly independent of laser transition diagonality within the lasing frequency range of the devices under test (3.2-3.7 THz) when cavity loss is kept low. Furthermore, the threshold current can be lowered by employing more diagonal transition designs, which can effectively suppress parasitic leakage caused by intermediate resonance between the injection and the downstream extraction levels. Nevertheless, the current carrying capacity through the designed lasing channel in more diagonal designs may sacrifice even more, leading to electrical instability and, potentially, complete inhibition of the device's lasing operation. We propose a hypothesis based on electric-field domain formation and competition/switching of different current-carrying channels to explain observed electrical instability in devices with lower oscillator strengths. The study indicates that not only should designers maximize Tmax during device optimization but also they should always consider the risk of electrical instability in device operation.

Nonmagnetic impurity resonances as a signature of sign-reversal pairing in FeAs-based superconductors.

PubMed

Zhang, Degang

2009-10-30

The energy band structure of FeAs-based superconductors is fitted by a tight-binding model with two Fe ions per unit cell and two degenerate orbitals per Fe ion. Based on this, superconductivity with extended s-wave pairing symmetry of the form cosk(x)+cosk(y) is examined. The local density of states near an impurity is also investigated by using the T-matrix approach. For the nonmagnetic scattering potential, we found that there exist two major resonances inside the gap. The height of the resonance peaks depends on the strength of the impurity potential. These in-gap resonances are originated in the Andreev's bound states due to the quasiparticle scattering between the hole Fermi surfaces around Gamma point with positive order parameter and the electron Fermi surfaces around M point with negative order parameter.

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

PubMed

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

2012-11-19

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

Erbium-doped fiber ring resonator for resonant fiber optical gyro applications

NASA Astrophysics Data System (ADS)

Li, Chunming; Zhao, Rui; Tang, Jun; Xia, Meijing; Guo, Huiting; Xie, Chengfeng; Wang, Lei; Liu, Jun

2018-04-01

This paper reports a fiber ring resonator with erbium-doped fiber (EDF) for resonant fiber optical gyro (RFOG). To analyze compensation mechanism of the EDF on resonator, a mathematical model of the erbium-doped fiber ring resonator (EDFRR) is established based on Jones matrix to be followed by the design and fabrication of a tunable EDFRR. The performances of the fabricated EDFRR were measured and the experimental Q-factor of 2 . 47 × 108 and resonant depth of 109% were acquired separately. Compared with the resonator without the EDF, the resonant depth and Q-factor of the proposed device are increased by 2.5 times and 14 times, respectively. A potential optimum shot noise limited resolution of 0 . 042∘ / h can be obtained for the RFOG, which is promising for low-cost and high precise detection.

Resonant snubber inverter

DOEpatents

Lai, Jih-Sheng; Young, Sr., Robert W.; Chen, Daoshen; Scudiere, Matthew B.; Ott, Jr., George W.; White, Clifford P.; McKeever, John W.

1997-01-01

A resonant, snubber-based, soft switching, inverter circuit achieves lossless switching during dc-to-ac power conversion and power conditioning with minimum component count and size. Current is supplied to the resonant snubber branches solely by the main inverter switches. Component count and size are reduced by use of a single semiconductor switch in the resonant snubber branches. Component count is also reduced by maximizing the use of stray capacitances of the main switches as parallel resonant capacitors. Resonance charging and discharging of the parallel capacitances allows lossless, zero voltage switching. In one embodiment, circuit component size and count are minimized while achieving lossless, zero voltage switching within a three-phase inverter.

Resonant snubber inverter

DOEpatents

Lai, J.S.; Young, R.W. Sr.; Chen, D.; Scudiere, M.B.; Ott, G.W. Jr.; White, C.P.; McKeever, J.W.

1997-06-24

A resonant, snubber-based, soft switching, inverter circuit achieves lossless switching during dc-to-ac power conversion and power conditioning with minimum component count and size. Current is supplied to the resonant snubber branches solely by the main inverter switches. Component count and size are reduced by use of a single semiconductor switch in the resonant snubber branches. Component count is also reduced by maximizing the use of stray capacitances of the main switches as parallel resonant capacitors. Resonance charging and discharging of the parallel capacitances allows lossless, zero voltage switching. In one embodiment, circuit component size and count are minimized while achieving lossless, zero voltage switching within a three-phase inverter. 14 figs.

Distinguishing Individual DNA Bases in a Network by Non-Resonant Tip-Enhanced Raman Scattering.

PubMed

Zhang, Rui; Zhang, Xianbiao; Wang, Huifang; Zhang, Yao; Jiang, Song; Hu, Chunrui; Zhang, Yang; Luo, Yi; Dong, Zhenchao

2017-05-08

The importance of identifying DNA bases at the single-molecule level is well recognized for many biological applications. Although such identification can be achieved by electrical measurements using special setups, it is still not possible to identify single bases in real space by optical means owing to the diffraction limit. Herein, we demonstrate the outstanding ability of scanning tunneling microscope (STM)-controlled non-resonant tip-enhanced Raman scattering (TERS) to unambiguously distinguish two individual complementary DNA bases (adenine and thymine) with a spatial resolution down to 0.9 nm. The distinct Raman fingerprints identified for the two molecules allow to differentiate in real space individual DNA bases in coupled base pairs. The demonstrated ability of non-resonant Raman scattering with super-high spatial resolution will significantly extend the applicability of TERS, opening up new routes for single-molecule DNA sequencing. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Single-frequency, fully integrated, miniature DPSS laser based on monolithic resonator

NASA Astrophysics Data System (ADS)

Dudzik, G.; Sotor, J.; Krzempek, K.; Soboń, G.; Abramski, K. M.

2014-02-01

We present a single frequency, stable, narrow linewidth, miniature laser sources operating at 532 nm (or 1064 nm) based on a monolithic resonators. Such resonators utilize birefringent filters formed by YVO4 beam displacer and KTP or YVO4 crystals to force single frequency operation at 532 nm or 1064 nm, respectively. In both configurations Nd:YVO4 gain crystal is used. The resonators dimensions are 1x1x10.5 mm3 and 1x1x8.5 mm3 for green and infrared configurations, respectively. Presented laser devices, with total dimensions of 40x52x120 mm3, are fully equipped with driving electronics, pump diode, optical and mechanical components. The highly integrated (36x15x65 mm3) low noise driving electronics with implemented digital PID controller was designed. It provides pump current and resonator temperature stability of ±30 μA@650 mA and ±0,003ºC, respectively. The laser parameters can be set and monitored via the USB interface by external application. The developed laser construction is universal. Hence, the other wavelengths can be obtained only by replacing the monolithic resonator. The optical output powers in single frequency regime was at the level of 42 mW@532 nm and 0.5 W@1064 nm with the long-term fluctuations of ±0.85 %. The linewidth and the passive frequency stability under the free running conditions were Δν < 100 kHz and 3ṡ10-9@1 s integration time, respectively. The total electrical power supply consumption of laser module was only 4 W. Presented compact, single frequency laser operating at 532 nm and 1064 nm may be used as an excellent source for laser vibrometry, interferometry or seed laser for fiber amplifiers.

Catheter-based flexible microcoil RF detectors for internal magnetic resonance imaging

NASA Astrophysics Data System (ADS)

Ahmad, M. M.; Syms, R. R. A.; Young, I. R.; Mathew, B.; Casperz, W.; Taylor-Robinson, S. D.; Wadsworth, C. A.; Gedroyc, W. M. W.

2009-07-01

Flexible catheter probes for magnetic resonance imaging (MRI) of the bile duct are demonstrated. The probes consist of a cytology brush modified to accept a resonant RF detector based on a spiral microcoil and hybrid integrated capacitors, and are designed for insertion into the duct via a non-magnetic endoscope during endoscopic retrograde cholangiopancreatography (ERCP). The coil must be narrow enough (<3 mm) to pass through the biopsy channel of the endoscope and sufficiently flexible to turn through 90° to enter the duct. Coils are fabricated as multi-turn electroplated conductors on a flexible base, and two designs formed on SU-8 and polyimide substrates are compared. It is shown that careful control of thermal load is used to obtain useable mechanical properties from SU-8, and that polyimide/SU-8 composites offer improved mechanical reliability. Good electrical performance is demonstrated and sub-millimetre resolution is obtained in 1H MRI experiments at 1.5 T magnetic field strength using test phantoms and in vitro liver tissue.

Purcell effect for active tuning of light scattering from semiconductor optical antennas.

PubMed

Holsteen, Aaron L; Raza, Søren; Fan, Pengyu; Kik, Pieter G; Brongersma, Mark L

2017-12-15

Subwavelength, high-refractive index semiconductor nanostructures support optical resonances that endow them with valuable antenna functions. Control over the intrinsic properties, including their complex refractive index, size, and geometry, has been used to manipulate fundamental light absorption, scattering, and emission processes in nanostructured optoelectronic devices. In this study, we harness the electric and magnetic resonances of such antennas to achieve a very strong dependence of the optical properties on the external environment. Specifically, we illustrate how the resonant scattering wavelength of single silicon nanowires is tunable across the entire visible spectrum by simply moving the height of the nanowires above a metallic mirror. We apply this concept by using a nanoelectromechanical platform to demonstrate active tuning. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Diode-laser frequency stabilization based on the resonant Faraday effect

NASA Technical Reports Server (NTRS)

Wanninger, P.; Valdez, E. C.; Shay, T. M.

1992-01-01

The authors present the results of a method for frequency stabilizing laser diodes based on the resonant Faraday effects. A Faraday cell in conjunction with a polarizer crossed with respect to the polarization of the laser diode comprises the intracavity frequency selective element. In this arrangement, a laser pull-in range of 9 A was measured, and the laser operated at a single frequency with a linewidth less than 6 MHz.

Thermal tuning of infrared resonant absorbers based on hybrid gold-VO{sub 2} nanostructures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kocer, Hasan; Department of Electrical Engineering, Turkish Military Academy, 06654 Ankara; Butun, Serkan

2015-04-20

Resonant absorbers based on plasmonic materials, metamaterials, and thin films enable spectrally selective absorption filters, where absorption is maximized at the resonance wavelength. By controlling the geometrical parameters of nano/microstructures and materials' refractive indices, resonant absorbers are designed to operate at wide range of wavelengths for applications including absorption filters, thermal emitters, thermophotovoltaic devices, and sensors. However, once resonant absorbers are fabricated, it is rather challenging to control and tune the spectral absorption response. Here, we propose and demonstrate thermally tunable infrared resonant absorbers using hybrid gold-vanadium dioxide (VO{sub 2}) nanostructure arrays. Absorption intensity is tuned from 90% to 20%more » and 96% to 32% using hybrid gold-VO{sub 2} nanowire and nanodisc arrays, respectively, by heating up the absorbers above the phase transition temperature of VO{sub 2} (68 °C). Phase change materials such as VO{sub 2} deliver useful means of altering optical properties as a function of temperature. Absorbers with tunable spectral response can find applications in sensor and detector applications, in which external stimulus such as heat, electrical signal, or light results in a change in the absorption spectrum and intensity.« less

Fiber-integrated refractive index sensor based on a diced Fabry-Perot micro-resonator.

PubMed

Suntsov, Sergiy; Rüter, Christian E; Schipkowski, Tom; Kip, Detlef

2017-11-20

We report on a fiber-integrated refractive index sensor based on a Fabry-Perot micro-resonator fabricated using simple diamond blade dicing of a single-mode step-index fiber. The performance of the device has been tested for the refractive index measurements of sucrose solutions as well as in air. The device shows a sensitivity of 1160 nm/RIU (refractive index unit) at a wavelength of 1.55 μm and a temperature cross-sensitivity of less than 10 -7   RIU/°C. Based on evaluation of the broadband reflection spectra, refractive index steps of 10 -5 of the solutions were accurately measured. The conducted coating of the resonator sidewalls with layers of a high-index material with real-time reflection spectrum monitoring could help to significantly improve the sensor performance.

3C-SiC microdisk mechanical resonators with multimode resonances at radio frequencies

NASA Astrophysics Data System (ADS)

Lee, Jaesung; Zamani, Hamidrera; Rajgopal, Srihari; Zorman, Christian A.; X-L Feng, Philip

2017-07-01

We report on the design, modeling, fabrication and measurement of single-crystal 3C-silicon carbide (SiC) microdisk mechanical resonators with multimode resonances operating at radio frequencies (RF). These microdisk resonators (center-clamped on a vertical stem pedestal) offer multiple flexural-mode resonances with frequencies dependent on both disk and anchor dimensions. The resonators are made using a novel fabrication method comprised of focused ion beam nanomachining and hydroflouic : nitric : acetic (HNA) acid etching. Resonance peaks (in the frequency spectrum) are detected through laser-interferometry measurements. Resonators with different dimensions are tested, and multimode resonances, mode splitting, energy dissipation (in the form of quality factor measurement) are investigated. Further, we demonstrate a feedback oscillator based on a passive 3C-SiC resonator. This investigation provides important guidelines for microdisk resonator development, ranging from an analytical prediction of frequency scaling law to fabrication, suggesting RF microdisk resonators can be good candidates for future sensing applications in harsh environments.

Fabrication of poly-crystalline Si-based Mie resonators via amorphous Si on SiO2 dewetting.

PubMed

Naffouti, Meher; David, Thomas; Benkouider, Abdelmalek; Favre, Luc; Ronda, Antoine; Berbezier, Isabelle; Bidault, Sebastien; Bonod, Nicolas; Abbarchi, Marco

2016-02-07

We report the fabrication of Si-based dielectric Mie resonators via a low cost process based on solid-state dewetting of ultra-thin amorphous Si on SiO2. We investigate the dewetting dynamics of a few nanometer sized layers annealed at high temperature to form submicrometric Si-particles. Morphological and structural characterization reveal the polycrystalline nature of the semiconductor matrix as well as rather irregular morphologies of the dewetted islands. Optical dark field imaging and spectroscopy measurements of the single islands reveal pronounced resonant scattering at visible frequencies. The linewidth of the low-order modes can be ∼20 nm in full width at half maximum, leading to a quality factor Q exceeding 25. These values reach the state-of-the-art ones obtained for monocrystalline Mie resonators. The simplicity of the dewetting process and its cost-effectiveness opens the route to exploiting it over large scales for applications in silicon-based photonics.

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

PubMed

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

2017-01-01

In view of the toxic potential of a bioweapon threat, rapid visual recognition and sensing of ricin has been of considerable interest while remaining a challenging task up to date. In this study, a gold nanopin-based colorimetric sensor is developed realizing a multicolor variation for ricin qualitative recognition and analysis. It is revealed that such plasmonic metasurfaces based on nanopin-cavity resonator exhibit reflective color appearance, due to the excitation of standing-wave resonances of narrow bandwidth in visible region. This clear color variation is a consequence of the reflective color mixing defined by different resonant wavelengths. In addition, the colored metasurfaces appear sharp color difference in a narrow refractive index range, which makes them especially well-suited for sensing applications. Therefore, this antibody-functionalized nanopin-cavity biosensor features high sensitivity and fast response, allowing for visual quantitative ricin detection within the range of 10-120 ng mL -1 (0.15 × 10 -9 -1.8 × 10 -9 m), a limit of detection of 10 ng mL -1 , and the typical measurement time of less than 10 min. The on-chip integration of such nanopin metasurfaces to portable colorimetric microfluidic device may be envisaged for the quantitative studies of a variety of biochemical molecules. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Colorimetric determination of Timolol concentration based on localized surface plasmon resonance of silver nanoparticles

NASA Astrophysics Data System (ADS)

Amirjani, Amirmostafa; Bagheri, Mozhgan; Heydari, Mojgan; Hesaraki, Saeed

2016-09-01

In this work, a rapid and simple colorimetric method based on the surface plasmon resonance of silver nanoparticles (AgNPs) was developed for the detection of the drug Timolol. The method used is based on the interaction of Timolol with the surface of the as-synthesized AgNPs, which promotes aggregation of the nanoparticles. This aggregation exploits the surface plasmon resonance through the electric dipole-dipole interaction and coupling among the agglomerated particles, hence bringing forth distinctive changes in the spectra as well as the color of colloidal silver. UV-vis spectrophotometery was used to monitor the changes of the localized surface plasmon resonance of AgNPs at wavelengths of 400 and 550 nm. The developed colorimetric sensor has a wide dynamic range of 1.0 × 10-7 M-1.0 × 10-3 M for detection of Timolol with a low detection limit of 1.2 × 10-6 M. The proposed method was successfully applied for the determination of Timolol concentration in ophthalmic eye-drop solution with a response time lower than 40 s.

Optical fiber tip interferometer gas pressure sensor based on anti-resonant reflecting guidance mechanism

NASA Astrophysics Data System (ADS)

Yang, Y. B.; Wang, D. N.; Xu, Ben; Wang, Z. K.

2018-05-01

We propose and demonstrate a gas pressure sensor based on an anti-resonant reflecting guidance (ARRG) mechanism in quartz capillary tube with an open cavity. The device is simple in fabrication by only fusion splicing a segment of capillary tube with single mode fiber. It has compact size, robust structure, convenient mode of operation, and high sensitivity of 4.278 nm/MPa. Moreover, as two Faby-Perot cavities exist in the device, which create the interference spectrum with several distinct resonance dips, a simultaneous gas pressure and temperature detection can be readily achieved by tracing two dip wavelengths. The error in the measurement due to the choice of different resonant dips can be effectively reduced by using the Fourier band pass filtering method.

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

NASA Astrophysics Data System (ADS)

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

2016-11-01

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

Silicon photonic resonator sensors and devices

NASA Astrophysics Data System (ADS)

Chrostowski, Lukas; Grist, Samantha; Flueckiger, Jonas; Shi, Wei; Wang, Xu; Ouellet, Eric; Yun, Han; Webb, Mitch; Nie, Ben; Liang, Zhen; Cheung, Karen C.; Schmidt, Shon A.; Ratner, Daniel M.; Jaeger, Nicolas A. F.

2012-02-01

Silicon photonic resonators, implemented using silicon-on-insulator substrates, are promising for numerous applications. The most commonly studied resonators are ring/racetrack resonators. We have fabricated these and other resonators including disk resonators, waveguide-grating resonators, ring resonator reflectors, contra-directional grating-coupler ring resonators, and racetrack-based multiplexer/demultiplexers. While numerous resonators have been demonstrated for sensing purposes, it remains unclear as to which structures provide the highest sensitivity and best limit of detection; for example, disc resonators and slot-waveguide-based ring resonators have been conjectured to provide an improved limit of detection. Here, we compare various resonators in terms of sensor metrics for label-free bio-sensing in a micro-fluidic environment. We have integrated resonator arrays with PDMS micro-fluidics for real-time detection of biomolecules in experiments such as antigen-antibody binding reaction experiments using Human Factor IX proteins. Numerous resonators are fabricated on the same wafer and experimentally compared. We identify that, while evanescent-field sensors all operate on the principle that the analyte's refractive index shifts the resonant frequency, there are important differences between implementations that lie in the relationship between the optical field overlap with the analyte and the relative contributions of the various loss mechanisms. The chips were fabricated in the context of the CMC-UBC Silicon Nanophotonics Fabrication course and workshop. This yearlong, design-based, graduate training program is offered to students from across Canada and, over the last four years, has attracted participants from nearly every Canadian university involved in photonics research. The course takes students through a full design cycle of a photonic circuit, including theory, modelling, design, and experimentation.

A phononic crystal strip based on silicon for support tether applications in silicon-based MEMS resonators and effects of temperature and dopant on its band gap characteristics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ha, Thi Dep, E-mail: hathidep@yahoo.com; Faculty of Electronic Technology, Industrial University of Ho Chi Minh City, Hochiminh City; Bao, JingFu, E-mail: baojingfu@uestc.edu.cn

Phononic crystals (PnCs) and n-type doped silicon technique have been widely employed in silicon-based MEMS resonators to obtain high quality factor (Q) as well as temperature-induced frequency stability. For the PnCs, their band gaps play an important role in the acoustic wave propagation. Also, the temperature and dopant doped into silicon can cause the change in its material properties such as elastic constants, Young’s modulus. Therefore, in order to design the simultaneous high Q and frequency stability silicon-based MEMS resonators by two these techniques, a careful design should study effects of temperature and dopant on the band gap characteristics tomore » examine the acoustic wave propagation in the PnC. Based on these, this paper presents (1) a proposed silicon-based PnC strip structure for support tether applications in low frequency silicon-based MEMS resonators, (2) influences of temperature and dopant on band gap characteristics of the PnC strips. The simulation results show that the largest band gap can achieve up to 33.56 at 57.59 MHz and increase 1280.13 % (also increase 131.89 % for ratio of the widest gaps) compared with the counterpart without hole. The band gap properties of the PnC strips is insignificantly effected by temperature and electron doping concentration. Also, the quality factor of two designed length extensional mode MEMS resonators with proposed PnC strip based support tethers is up to 1084.59% and 43846.36% over the same resonators with PnC strip without hole and circled corners, respectively. This theoretical study uses the finite element analysis in COMSOL Multiphysics and MATLAB softwares as simulation tools. This findings provides a background in combination of PnC and dopant techniques for high performance silicon-based MEMS resonators as well as PnC-based MEMS devices.« less

A novel flow sensor based on resonant sensing with two-stage microleverage mechanism.

PubMed

Yang, B; Guo, X; Wang, Q H; Lu, C F; Hu, D

2018-04-01

The design, simulation, fabrication, and experiments of a novel flow sensor based on resonant sensing with a two-stage microleverage mechanism are presented in this paper. Different from the conventional detection methods for flow sensors, two differential resonators are adopted to implement air flow rate transformation through two-stage leverage magnification. The proposed flow sensor has a high sensitivity since the adopted two-stage microleverage mechanism possesses a higher amplification factor than a single-stage microleverage mechanism. The modal distribution and geometric dimension of the two-stage leverage mechanism and hair are analyzed and optimized by Ansys simulation. A digital closed-loop driving technique with a phase frequency detector-based coordinate rotation digital computer algorithm is implemented for the detection and locking of resonance frequency. The sensor fabricated by the standard deep dry silicon on a glass process has a device dimension of 5100 μm (length) × 5100 μm (width) × 100 μm (height) with a hair diameter of 1000 μm. The preliminary experimental results demonstrate that the maximal mechanical sensitivity of the flow sensor is approximately 7.41 Hz/(m/s) 2 at a resonant frequency of 22 kHz for the hair height of 9 mm and increases by 2.42 times as hair height extends from 3 mm to 9 mm. Simultaneously, a detection-limit of 3.23 mm/s air flow amplitude at 60 Hz is confirmed. The proposed flow sensor has great application prospects in the micro-autonomous system and technology, self-stabilizing micro-air vehicles, and environmental monitoring.

A novel flow sensor based on resonant sensing with two-stage microleverage mechanism

NASA Astrophysics Data System (ADS)

Yang, B.; Guo, X.; Wang, Q. H.; Lu, C. F.; Hu, D.

2018-04-01

The design, simulation, fabrication, and experiments of a novel flow sensor based on resonant sensing with a two-stage microleverage mechanism are presented in this paper. Different from the conventional detection methods for flow sensors, two differential resonators are adopted to implement air flow rate transformation through two-stage leverage magnification. The proposed flow sensor has a high sensitivity since the adopted two-stage microleverage mechanism possesses a higher amplification factor than a single-stage microleverage mechanism. The modal distribution and geometric dimension of the two-stage leverage mechanism and hair are analyzed and optimized by Ansys simulation. A digital closed-loop driving technique with a phase frequency detector-based coordinate rotation digital computer algorithm is implemented for the detection and locking of resonance frequency. The sensor fabricated by the standard deep dry silicon on a glass process has a device dimension of 5100 μm (length) × 5100 μm (width) × 100 μm (height) with a hair diameter of 1000 μm. The preliminary experimental results demonstrate that the maximal mechanical sensitivity of the flow sensor is approximately 7.41 Hz/(m/s)2 at a resonant frequency of 22 kHz for the hair height of 9 mm and increases by 2.42 times as hair height extends from 3 mm to 9 mm. Simultaneously, a detection-limit of 3.23 mm/s air flow amplitude at 60 Hz is confirmed. The proposed flow sensor has great application prospects in the micro-autonomous system and technology, self-stabilizing micro-air vehicles, and environmental monitoring.

One-dimensional Multi-channel Photonic Crystal Resonators based on Silicon-On-Insulator with High Quality Factor

NASA Astrophysics Data System (ADS)

Faneca, Joaquin; Perova, Tatiana S.; Tolmachev, Vladimir; Baldycheva, Anna

2018-05-01

We have theoretically and experimentally demonstrated a Fabry-Pérot (FP) resonators based on a Si-air one-dimensional photonic crystal (1D PhC) with coupled triple-cavity modes (or defects). These defects are obtained by filling selected air channels in the 1D PhC with an actively reconfigurable fluid. Simulations of the optical properties of these FP resonators were performed in the wide infrared spectral range. It is shown that by changing the refractive index, nc, of the fluid simultaneously in all three channels, a set of narrow triple resonance peaks can be obtained within wide stop-bands of different order in the infrared range. In addition, at certain values of nc, splitting of the triple resonance peaks into a doublet and a single peak with a significantly larger quality factor, Q=21200, occurs. Prototype devices based on Silicon-On-Insulator platform were fabricated and characterized by electro-optical and spectroscopic measurements. The electro-optical measurements demonstrate the possibility of refractive index manipulation of the filler in the FP channels individually or simultaneously. Spectroscopic measurements performed in the range 1540 – 1630 nm using fibre-coupling confirm the presence of triple resonance peaks in the 3rd stop-band in the absence of an electric field applied to the FP channels. At an applied voltage of 10 V to the middle channel, an increase of Q to 3720 in the single peak is registered which is the highest Q demonstrated in SOI based 1D PhC to date.

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

PubMed

Santillan, Arturo O; Cutanda-Henríquez, Vicente

2008-11-01

An investigation on the resonance frequency shift for a plane-wave mode in a cylindrical cavity produced by a rigid sphere is reported in this paper. This change of the resonance frequency has been previously considered as a cause of oscillational instabilities in single-mode acoustic levitation devices. It is shown that the use of the Boltzmann-Ehrenfest principle of adiabatic invariance allows the derivation of an expression for the resonance frequency shift in a simpler and more direct way than a method based on a Green's function reported in literature. The position of the sphere can be any point along the axis of the cavity. Obtained predictions of the resonance frequency shift with the deduced equation agree quite well with numerical simulations based on the boundary element method. The results are also confirmed by experiments. The equation derived from the Boltzmann-Ehrenfest principle appears to be more general, and for large spheres, it gives a better approximation than the equation previously reported.

Self-Reference Refractive Index Sensor Based on Independently Controlled Double Resonances in Side-Coupled U-Shaped Resonators.

PubMed

Ren, Xiaobin; Ren, Kun; Ming, Chengguo

2018-04-28

A plasmonic, refractive, index nanosensor is investigated theoretically and numerically in two U-shaped cavities side-coupled to a metal⁻dielectric⁻metal (MDM) waveguide. A transparency window between two transmission dips is observed. The physical origin of the transmission phenomenon is revealed by mapping the magnetic field distribution. Independent double resonances are realized through the proposed design. Double resonances showed diverse responses to the variations of the structural dimensions. In particular, they presented different dependences on a refraction index of the medium in an individual resonator. One resonance exhibited a remarkable shift with the increase of the refraction index; however, the other resonance remained unchanged. On the basis of this unique characteristic of differing sensitivities, self-reference sensing is discussed. The nanosensor yielded a high sensitivity of 917 nm/RIU and a figure of merit of 180 RIU −1 . This work is helpful in terms of the design of on-chip optical sensors with high sensitivity and improved detection accuracy in complicated environments.

Design and development of repetitive capacitor charging power supply based on series-parallel resonant converter topology.

PubMed

Patel, Ankur; Nagesh, K V; Kolge, Tanmay; Chakravarthy, D P

2011-04-01

LCL resonant converter based repetitive capacitor charging power supply (CCPS) is designed and developed in the division. The LCL converter acts as a constant current source when switching frequency is equal to the resonant frequency. When both resonant inductors' values of LCL converter are same, it results in inherent zero current switching (ZCS) in switches. In this paper, ac analysis with fundamental frequency approximation of LCL resonant tank circuit, frequency dependent of current gain converter followed by design, development, simulation, and practical result is described. Effect of change in switching frequency and resonant frequency and change in resonant inductors ratio on CCPS will be discussed. An efficient CCPS of average output power of 1.2 kJ/s, output voltage 3 kV, and 300 Hz repetition rate is developed in the division. The performance of this CCPS has been evaluated in the laboratory by charging several values of load capacitance at various repetition rates. These results indicate that this design is very feasible for use in capacitor-charging applications. © 2011 American Institute of Physics

Mitigating Thermoelastic Dissipation of Flexural Micromechanical Resonators by Decoupling Resonant Frequency from Thermal Relaxation Rate

NASA Astrophysics Data System (ADS)

Zhou, Xin; Xiao, Dingbang; Wu, Xuezhong; Li, Qingsong; Hou, Zhanqiang; He, Kaixuan; Wu, Yulie

2017-12-01

This paper reports an alternative design strategy to reduce thermoelastic dissipation (TED) for isothermal-mode micromechanical resonators. This involves hanging lumped masses on a frame structure to decouple the resonant frequency and the effective beamwidth of the resonators, which enables the separation of the thermal relaxation rate and frequency of vibration. This approach is validated using silicon-based micromechanical disklike resonators engineered to isolate TED. A threefold improvement in the quality factor and a tenfold improvement in the decay-time constant is demonstrated. This work proposes a solution for isothermal-mode (flexural) micromechanical resonators to effectively mitigate TED. Specifically, this approach is ideal for designing high-performance gyroscope resonators based on microelectromechanical systems (MEMS) technology. It may pave the way for the next generation inertial-grade MEMS gyroscope, which remains a great challenge and is very appealing.

Graphene-based perfect optical absorbers harnessing guided mode resonances.

PubMed

Grande, M; Vincenti, M A; Stomeo, T; Bianco, G V; de Ceglia, D; Aközbek, N; Petruzzelli, V; Bruno, G; De Vittorio, M; Scalora, M; D'Orazio, A

2015-08-10

We investigate graphene-based optical absorbers that exploit guided mode resonances (GMRs) attaining theoretically perfect absorption over a bandwidth of few nanometers (over the visible and near-infrared ranges) with a 40-fold increase of the monolayer graphene absorption. We analyze the influence of the geometrical parameters on the absorption rate and the angular response for oblique incidence. Finally, we experimentally verify the theoretical predictions in a one-dimensional, dielectric grating by placing it near either a metallic or a dielectric mirror, thus achieving very good agreement between numerical predictions and experimental results.

Resonance-Based Detection of Magnetic Nanoparticles and Microbeads Using Nanopatterned Ferromagnets

NASA Astrophysics Data System (ADS)

Sushruth, Manu; Ding, Junjia; Duczynski, Jeremy; Woodward, Robert C.; Begley, Ryan A.; Fangohr, Hans; Fuller, Rebecca O.; Adeyeye, Adekunle O.; Kostylev, Mikhail; Metaxas, Peter J.

2016-10-01

Biosensing with ferromagnet-based magnetoresistive devices has been dominated by electrical detection of particle-induced changes to a device's (quasi-)static magnetic configuration. There are however potential advantages to be gained from using field dependent, high frequency resonant magnetization dynamics for magnetic particle detection. Here, we demonstrate the use of nanoconfined ferromagnetic resonances in periodically nanopatterned magnetic films for the detection of adsorbed magnetic particles having diameters ranging from 6 nm to 4 μ m . The nanopatterned films contain arrays of holes which appear to act as preferential adsorption sites for small particles. Hole-localized particles act in unison to shift the frequencies of the patterned layer's ferromagnetic-resonance modes, with shift polarities determined by the localization of each mode within the nanopattern's repeating unit cell. The same polarity shifts are observed for a large range of coverages, even when quasicontinuous particle sheets form above the hole-localized particles. For large particles, preferential adsorption no longer occurs, leading to resonance shifts with polarities that are independent of the mode localization, and amplitudes that are comparable to those seen in continuous layers. Indeed, for nanoparticles adsorbed onto a continuous layer, the particle-induced shift of the layer's fundamental mode is up to 10 times less than that observed for nanoconfined modes in the nanopatterned systems, the low shift being induced by relatively weak fields emanating beyond the particle in the direction of the static applied field. This result highlights the importance of having particles consistently positioned in the close vicinity of confined modes.

High-precision micro-displacement optical-fiber sensor based on surface plasmon resonance.

PubMed

Zhu, Zongda; Liu, Lu; Liu, Zhihai; Zhang, Yu; Zhang, Yaxun

2017-05-15

We propose and demonstrate a novel optical-fiber micro-displacement sensor based on surface plasmon resonance (SPR) by fabricating a Kretschmann configuration on graded-index multimode fiber (GIMMF). We employ a single-mode fiber to change the radial position of the incident beam as the displacement. In the GIMMF, the angle between the light beam and fiber axis, which is closely related to the resonance angle, is changed by the displacement; thus, the resonance wavelength of the fiber SPR shifts. This micro-displacement fiber sensor has a wide detection range of 0-25 μm, a high sensitivity with maximum up to 10.32 nm/μm, and a nanometer resolution with minimum to 2 nm, which transcends almost all of other optical-fiber micro-displacement sensors. In addition, we also research that increasing the fiber polishing angle or medium refractive index can improve the sensitivity. This micro-displacement sensor will have a great significance in many industrial applications and provide a neoteric, rapid, and accurate optical measurement method in micro-displacement.

Carbon Nanotube based Nanotechnolgy

NASA Astrophysics Data System (ADS)

Meyyappan, M.

2000-10-01

Carbon nanotube(CNT) was discovered in the early 1990s and is an off-spring of C60(the fullerene or buckyball). CNT, depending on chirality and diameter, can be metallic or semiconductor and thus allows formation of metal-semiconductor and semiconductor-semiconductor junctions. CNT exhibits extraordinary electrical and mechanical properties and offers remarkable potential for revolutionary applications in electronics devices, computing and data storage technology, sensors, composites, storage of hydrogen or lithium for battery development, nanoelectromechanical systems(NEMS), and as tip in scanning probe microscopy(SPM) for imaging and nanolithography. Thus the CNT synthesis, characterization and applications touch upon all disciplines of science and engineering. A common growth method now is based on CVD though surface catalysis is key to synthesis, in contrast to many CVD applications common in microelectronics. A plasma based variation is gaining some attention. This talk will provide an overview of CNT properties, growth methods, applications, and research challenges and opportunities ahead.

Identifying resonance frequency deviations for high order nano-wire ring resonator filters based on a coupling strength variation

NASA Astrophysics Data System (ADS)

Park, Sahnggi; Kim, Kap-Joong; Kim, Duk-Jun; Kim, Gyungock

2009-02-01

Third order ring resonators are designed and their resonance frequency deviations are analyzed experimentally by processing them with E-beam lithography and ICP etching in a CMOS nano-Fabrication laboratory. We developed a reliable method to identify and reduce experimentally the degree of deviation of each ring resonance frequency before completion of the fabrication process. The identified deviations can be minimized by the way to be presented in this paper. It is expected that this method will provide a significant clue to make a high order multi-channel ring resonators.

MRI (Magnetic Resonance Imaging)

MedlinePlus

... IV in the arm. MRI Research Programs at FDA Magnetic Resonance Imaging (MRI) Safety Electromagnetic Modeling Related ... Resonance Imaging Equipment in Clinical Use (March 2015) FDA/CDER: Information on Gadolinium-Based Contrast Agents Safety ...

Refraction index sensor based on phase resonances in a subwavelength structure with double period.

PubMed

Skigin, Diana C; Lester, Marcelo

2016-10-01

In this paper, we numerically demonstrate a refraction index sensor based on phase resonance excitation in a subwavelength-slit structure with a double period. The sensor consists of a metal layer with subwavelength slots arranged in a bi-periodic form, separated from a high refraction index medium. Between the metallic structure and the incident medium, a dielectric waveguide is formed whose refraction index is going to be determined. Variations in the refraction index of the waveguide are detected as shifts in the peaks of transmitted intensity originated by resonant modes supported by the compound metallic structure. At normal incidence, the spectral position of these resonant peaks exhibits a linear or a quadratic dependence with the refraction index, which permits us to obtain the unknown refraction index value with a high precision for a wide range of wavelengths. Since the operating principle of the sensor is due to the morphological resonances of the slits' structure, this device can be scaled to operate in different wavelength ranges while keeping similar characteristics.

Dielectric micro-resonator-based opto-mechanical systems for sensing applications

NASA Astrophysics Data System (ADS)

Ali, Amir Roushdy

In recent years, whispering gallery mode (WGM), or morphology dependent optical resonances (MDR) of dielectric micro-resonators have attracted interest with proposed applications in a wide range of areas due to the high optical quality factors, Q, they can exhibit (reaching ~ 10. 9 for silica spheres). Micro-resonator WGMs have been used in applications that include those in spectroscopy, micro-cavity laser technology, optical communications (switching, filtering and multiplexing), sensors technologies and even chemical and biological sensing. The WGM of these dielectric micro-resonators are highly sensitive to morphological changes (such as the size, shape, or refractive index) of the resonance cavity and hence, can be tuned by causing a minute change in the physical condition of the surrounding. In this dissertation, we have been creating opto-mechanical systems, which at their most basic, are extraordinarily sensitive sensors. One of the ultimate goals of this dissertation is to develop sensors capable of detecting the extremely small electric field changes. To improve the performance of the sensors, we couple a polymer cantilever beam to a dielectric micro-resonator. The eventual use of such ultra sensitive electric filed sensors could include neural-machine interfaces for advanced prosthetics devices. The work presented here includes a basic analysis and experimental investigations of the electric field sensitivity and range of micro-resonators of several different materials and geometries followed by the electric field sensor design, testing, and characterization. Also, the effects of angular velocity on the WGM shifts of spherical micro-resonators are also investigated. The elastic deformation that is induced on a spinning resonator due to the centrifugal force may lead to a sufficient shift in the optical resonances and therefore interfering with its desirable operational sensor design. Furthermore, this principle could be used for the development of

Wireless Actuation of Micromechanical Resonators

NASA Astrophysics Data System (ADS)

Mateen, Farrukh; Maedler, Carsten; Erramilli, Shyamsunder; Mohanty, Pritiraj

Wireless transfer of power is of fundamental and technical interest with applications ranging from remote operation of electronics, biomedical implants, and device actuation where hard-wired power sources are neither desirable nor practical. In particular, biomedical implants in the body or the brain need small footprint power receiving elements for wireless charging, which can be accomplished by micromechanical resonators. In contrast for fundamental experiments, ultra low-power wireless operation of micromechanical resonators in the microwave range makes low-temperature studies of mechanical systems in the quantum regime possible, where heat carried by the electrical wires in standard actuation techniques is detrimental to maintaining the resonator in a quantum state. We demonstrate successful actuation of micron-sized silicon-based piezoelectric resonators with resonance frequencies from 36 MHz to 120 MHz, at power levels of nanowatts and distances of about 3 feet, including polarization, distance and power dependence measurements. Our demonstration of wireless actuation of micromechanical resonators via electric-field coupling down to nanowatt levels enables a multitude of applications based on micromechanical resonators, inaccessible until now.

Tire-road friction coefficient estimation based on the resonance frequency of in-wheel motor drive system

NASA Astrophysics Data System (ADS)

Chen, Long; Bian, Mingyuan; Luo, Yugong; Qin, Zhaobo; Li, Keqiang

2016-01-01

In this paper, a resonance frequency-based tire-road friction coefficient (TRFC) estimation method is proposed by considering the dynamics performance of the in-wheel motor drive system under small slip ratio conditions. A frequency response function (FRF) is deduced for the drive system that is composed of a dynamic tire model and a simplified motor model. A linear relationship between the squared system resonance frequency and the TFRC is described with the FRF. Furthermore, the resonance frequency is identified by the Auto-Regressive eXogenous model using the information of the motor torque and the wheel speed, and the TRFC is estimated thereafter by a recursive least squares filter with the identified resonance frequency. Finally, the effectiveness of the proposed approach is demonstrated through simulations and experimental tests on different road surfaces.

A macroscopic non-destructive testing system based on the cantilever-sample contact resonance

NASA Astrophysics Data System (ADS)

Fu, Ji; Lin, Lizhi; Zhou, Xilong; Li, Yingwei; Li, Faxin

2012-12-01

Detecting the inside or buried defects in materials and structures is always a challenge in the field of nondestructive testing (NDT). In this paper, enlightened by the operation principle of the contact resonance force microscopy or atomic force acoustic microscopy (AFAM), we proposed a macroscopic NDT system based on contact resonance of the cantilever-sample surface to detect the local stiffness variations in materials or structures. We fabricated a piezoelectric unimorph with the dimension typically of 150 mm × 8 mm × 2 mm to act as a macroscopic cantilever, whose flexural mode vibration was driven by a wideband power amplifier together with a signal generator. The vibration signal of the macroscopic cantilever is detected by a high sensitive strain gauge bonded on the cantilever surface which is much more stable than the laser diode sensor in AFAM, thus making it very suitable for outdoor operations. Scanning is realized by a three-dimensional motorized stage with the Z axis for pressing force setting. The whole system is controlled by a LabVIEW-based homemade software. Like the AFAM, this NDT system can also work in two modes, i.e., the single-frequency mode and the resonance-tracking mode. In the latter mode, the contact stiffness at each pixel of the sample can be obtained by using the measured contact resonance frequency and a beam dynamics model. Testing results of this NDT system on a grid structure with an opaque panel show that in both modes the prefabricated defect beneath the panel can be detected and the grid structures can be clearly "seen," which indicates the validity of this NDT system. The sensitivity of this NDT system was also examined.

Cyclotron resonance in HgTe/CdTe-based heterostructures in high magnetic fields

PubMed Central

2012-01-01

Cyclotron resonance study of HgTe/CdTe-based quantum wells with both inverted and normal band structures in quantizing magnetic fields was performed. In semimetallic HgTe quantum wells with inverted band structure, a hole cyclotron resonance line was observed for the first time. In the samples with normal band structure, interband transitions were observed with wide line width due to quantum well width fluctuations. In all samples, impurity-related magnetoabsorption lines were revealed. The obtained results were interpreted within the Kane 8·8 model, the valence band offset of CdTe and HgTe, and the Kane parameter EP being adjusted. PMID:23013642

Equal intensity double plasmon resonance of bimetallic quasi-nanocomposites based on sandwich geometry

NASA Astrophysics Data System (ADS)

Chakravadhanula, V. S. K.; Elbahri, M.; Schürmann, U.; Takele, H.; Greve, H.; Zaporojtchenko, V.; Faupel, F.

2008-06-01

We report a strategy to achieve a material showing equal intensity double plasmon resonance (EIDPR) based on sandwich geometry. We studied the interaction between localized plasmon resonances associated with different metal clusters (Au/Ag) on Teflon AF (TAF) in sandwich geometry. Engineering the EIDPR was done by tailoring the amount of Au/Ag and changing the TAF thickness. The samples were investigated by transmission electron microscopy (TEM) and UV-visible spectroscopy. Interestingly, and in agreement with the dipole-surface interaction, the critical barrier thickness for an optimum EIDPR was observed at 3.3 nm. The results clearly show a plasmon sequence effect and visualize the role of plasmon decay.

Dissociations between behavioural and functional magnetic resonance imaging-based evaluations of cognitive function after brain injury

PubMed Central

Bardin, Jonathan C.; Fins, Joseph J.; Katz, Douglas I.; Hersh, Jennifer; Heier, Linda A.; Tabelow, Karsten; Dyke, Jonathan P.; Ballon, Douglas J.; Schiff, Nicholas D.

2011-01-01

Functional neuroimaging methods hold promise for the identification of cognitive function and communication capacity in some severely brain-injured patients who may not retain sufficient motor function to demonstrate their abilities. We studied seven severely brain-injured patients and a control group of 14 subjects using a novel hierarchical functional magnetic resonance imaging assessment utilizing mental imagery responses. Whereas the control group showed consistent and accurate (for communication) blood-oxygen-level-dependent responses without exception, the brain-injured subjects showed a wide variation in the correlation of blood-oxygen-level-dependent responses and overt behavioural responses. Specifically, the brain-injured subjects dissociated bedside and functional magnetic resonance imaging-based command following and communication capabilities. These observations reveal significant challenges in developing validated functional magnetic resonance imaging-based methods for clinical use and raise interesting questions about underlying brain function assayed using these methods in brain-injured subjects. PMID:21354974

Intensity-based readout of resonant-waveguide grating biosensors: Systems and nanostructures

NASA Astrophysics Data System (ADS)

Paulsen, Moritz; Jahns, Sabrina; Gerken, Martina

2017-09-01

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.

Right ventricular volumes assessed by echocardiographic three-dimensional knowledge-based reconstruction compared with magnetic resonance imaging in a clinical setting.

PubMed

Neukamm, Christian; Try, Kirsti; Norgård, Gunnar; Brun, Henrik

2014-01-01

A technique that uses two-dimensional images to create a knowledge-based, three-dimensional model was tested and compared to magnetic resonance imaging. Measurement of right ventricular volumes and function is important in the follow-up of patients after pulmonary valve replacement. Magnetic resonance imaging is the gold standard for volumetric assessment. Echocardiographic methods have been validated and are attractive alternatives. Thirty patients with tetralogy of Fallot (25 ± 14 years) after pulmonary valve replacement were examined. Magnetic resonance imaging volumetric measurements and echocardiography-based three-dimensional reconstruction were performed. End-diastolic volume, end-systolic volume, and ejection fraction were measured, and the results were compared. Magnetic resonance imaging measurements gave coefficient of variation in the intraobserver study of 3.5, 4.6, and 5.3 and in the interobserver study of 3.6, 5.9, and 6.7 for end-diastolic volume, end-systolic volume, and ejection fraction, respectively. Echocardiographic three-dimensional reconstruction was highly feasible (97%). In the intraobserver study, the corresponding values were 6.0, 7.0, and 8.9 and in the interobserver study 7.4, 10.8, and 13.4. In comparison of the methods, correlations with magnetic resonance imaging were r = 0.91, 0.91, and 0.38, and the corresponding coefficient of variations were 9.4, 10.8, and 14.7. Echocardiography derived volumes (mL/m(2)) were significantly higher than magnetic resonance imaging volumes in end-diastolic volume 13.7 ± 25.6 and in end-systolic volume 9.1 ± 17.0 (both P < .05). The knowledge-based three-dimensional right ventricular volume method was highly feasible. Intra and interobserver variabilities were satisfactory. Agreement with magnetic resonance imaging measurements for volumes was reasonable but unsatisfactory for ejection fraction. Knowledge-based reconstruction may replace magnetic resonance imaging measurements for serial follow

Tunable resonator-based devices for producing variable delays and narrow spectral linewidths

NASA Technical Reports Server (NTRS)

Savchenkov, Anatoliy (Inventor); Maleki, Lutfollah (Inventor); Matsko, Andrey B. (Inventor); Ilchenko, Vladimir (Inventor)

2006-01-01

Devices with two or more coupled resonators to produce narrow spectral responses due to interference of signals that transmit through the resonators and techniques for operating such devices to achieve certain operating characteristics are described. The devices may be optical devices where optical resonators such as whispering gallery mode resonators may be used. In one implementation, at least one of the coupled optical resonators is a tunable resonator and is tuned to change its resonance frequency to tune the spectral response of the device. The described devices and techniques may be applied in optical filters, optical delays, optical waveform generators, and other applications.

Optically-controlled extinction ratio and Q-factor tunable silicon microring resonators based on optical forces

NASA Astrophysics Data System (ADS)

Long, Yun; Wang, Jian

2014-06-01

Tunability is a desirable property of microring resonators to facilitate superior performance. Using light to control light, we present an alternative simple approach to tuning the extinction ratio (ER) and Q-factor of silicon microring resonators based on optical forces. We design an opto-mechanical tunable silicon microring resonator consisting of an add-drop microring resonator and a control-light-carrying waveguide (``controlling'' waveguide). One of the two bus waveguides of the microring resonator is a deformable nanostring put in parallel with the ``controlling'' waveguide. The tuning mechanism relies on the optical force induced deflection of suspended nanostring, leading to the change of coupling coefficient of microring and resultant tuning of ER and Q-factor. Two possible geometries, i.e. double-clamped nanostring and cantilever nanostring, are studied in detail for comparison. The obtained results imply a favorable structure with the microring positioned at the end of the cantilever nanostring. It features a wide tuning range of ER from 5.6 to 39.9 dB and Q-factor from 309 to 639 as changing the control power from 0 to 1.4 mW.

Compact wideband filter element-based on complementary split-ring resonators

NASA Astrophysics Data System (ADS)

Horestani, Ali K.; Shaterian, Zahra; Withayachumnankul, Withawat; Fumeaux, Christophe; Al-Sarawi, Said; Abbott, Derek

2011-12-01

A double resonance defected ground structure is proposed as a filter element. The structure involves a transmission line loaded with complementary split ring resonators embedded in a dumbbell shape defected ground structure. By using a parametric study, it is demonstrated that the two resonance frequencies can be independently tuned. Therefore the structure can be used for different applications such as dual bandstop filters and wide bandstop filters.

Acoustic agglomeration of fine particles based on a high intensity acoustical resonator

NASA Astrophysics Data System (ADS)

Zhao, Yun; Zeng, Xinwu; Tian, Zhangfu

2015-10-01

Acoustic agglomeration (AA) is considered to be a promising method for reducing the air pollution caused by fine aerosol particles. Removal efficiency and energy consuming are primary parameters and generally have a conflict with each other for the industry applications. It was proved that removal efficiency is increased with sound intensity and optimal frequency is presented for certain polydisperse aerosol. As a result, a high efficiency and low energy cost removal system was constructed using acoustical resonance. High intensity standing wave is generated by a tube system with abrupt section driven by four loudspeakers. Numerical model of the tube system was built base on the finite element method, and the resonance condition and SPL increase were confirmd. Extensive tests were carried out to investigate the acoustic field in the agglomeration chamber. Removal efficiency of fine particles was tested by the comparison of filter paper mass and particle size distribution at different operating conditions including sound pressure level (SPL), and frequency. The experimental study has demonstrated that agglomeration increases with sound pressure level. Sound pressure level in the agglomeration chamber is between 145 dB and 165 dB from 500 Hz to 2 kHz. The resonance frequency can be predicted with the quarter tube theory. Sound pressure level gain of more than 10 dB is gained at resonance frequency. With the help of high intensity sound waves, fine particles are reduced greatly, and the AA effect is enhanced at high SPL condition. The optimal frequency is 1.1kHz for aerosol generated by coal ash. In the resonace tube, higher resonance frequencies are not the integral multiplies of the first one. As a result, Strong nonlinearity is avoided by the dissonant characteristic and shock wave is not found in the testing results. The mechanism and testing system can be used effectively in industrial processes in the future.

Adjustable low frequency and broadband metamaterial absorber based on magnetic rubber plate and cross resonator

NASA Astrophysics Data System (ADS)

Cheng, Yongzhi; Nie, Yan; Wang, Xian; Gong, Rongzhou

2014-02-01

In this paper, the magnetic rubber plate absorber (MRPA) and metamaterial absorber (MA) based on MRP substrate were proposed and studied numerically and experimentally. Based on the characteristic of L-C resonances, experimental results show that the MA composed of cross resonator (CR) embedded single layer MRP could be adjustable easily by changing the wire length and width of CR structure and MRP thickness. Finally, experimental results show that the MA composed of CR-embedded two layers MRP with the total thickness of 2.42 mm exhibit a -10 dB absorption bandwidth from 1.65 GHz to 3.7 GHz, which is 1.86 times wider than the same thickness MRPA.

Optical notch filter with tunable bandwidth based on guided-mode resonant polarization-sensitive spectral feature.

PubMed

Qian, Linyong; Zhang, Dawei; Dai, Bo; Wang, Qi; Huang, Yuanshen; Zhuang, Songlin

2015-07-13

A novel bandwidth-tunable notch filter is proposed based on the guided-mode resonance effect. The notch is created due to the superposition spectra response of two guided-mode resonant filters. The compact, bandwidth tuning capability is realized by taking advantage the effect of spectra-to-polarization sensitivity in one-dimensional classical guided-mode resonance filter, and using a liquid crystal polarization rotator for precise and simple polarization control. The operation principle and the design of the device are presented, and we demonstrate it experimentally. The central wavelength is fixed at 766.4 nm with a relatively symmetric profile. The full width at half maximum bandwidth could be tuned from 8.6 nm to 18.2 nm by controlling the applied voltage in electrically-driving polarization rotator.

Mathematical Development and Computational Analysis of Harmonic Phase-Magnetic Resonance Imaging (HARP-MRI) Based on Bloch Nuclear Magnetic Resonance (NMR) Diffusion Model for Myocardial Motion.

PubMed

Dada, Michael O; Jayeoba, Babatunde; Awojoyogbe, Bamidele O; Uno, Uno E; Awe, Oluseyi E

2017-09-13

Harmonic Phase-Magnetic Resonance Imaging (HARP-MRI) is a tagged image analysis method that can measure myocardial motion and strain in near real-time and is considered a potential candidate to make magnetic resonance tagging clinically viable. However, analytical expressions of radially tagged transverse magnetization in polar coordinates (which is required to appropriately describe the shape of the heart) have not been explored because the physics required to directly connect myocardial deformation of tagged Nuclear Magnetic Resonance (NMR) transverse magnetization in polar geometry and the appropriate harmonic phase parameters are not yet available. The analytical solution of Bloch NMR diffusion equation in spherical geometry with appropriate spherical wave tagging function is important for proper analysis and monitoring of heart systolic and diastolic deformation with relevant boundary conditions. In this study, we applied Harmonic Phase MRI method to compute the difference between tagged and untagged NMR transverse magnetization based on the Bloch NMR diffusion equation and obtained radial wave tagging function for analysis of myocardial motion. The analytical solution of the Bloch NMR equations and the computational simulation of myocardial motion as developed in this study are intended to significantly improve healthcare for accurate diagnosis, prognosis and treatment of cardiovascular related deceases at the lowest cost because MRI scan is still one of the most expensive anywhere. The analysis is fundamental and significant because all Magnetic Resonance Imaging techniques are based on the Bloch NMR flow equations.

Low-frequency band gap of locally resonant phononic crystals with a dual-base plate.

PubMed

Zuo, Shuguang; Huang, Haidong; Wu, Xudong; Zhang, Minghai; Ni, Tianxin

2018-03-01

To achieve a wider band gap and a lower cut-on frequency, a locally resonant phononic crystal (LRPC) with a dual-base plate is investigated in this paper. Compared with the LRPC with a single plate, the band structure of the LRPC with a dual-base plate is calculated using the method of plane wave expansion and verified by the finite element method. According to the analysis of the band curves of the LRPC with a dual-base plate, the mechanisms are explained. Next, the influences of the thickness of the plates, the stiffness of the springs, the mass of resonators, and the lattice constant are also investigated. The results show that the structural asymmetry between the upper and the lower plate is conducive to reducing the cut-on frequency and broadening the band gap effectively. The results indicate a different approach for the application of LRPC in vibration and noise control.

MEMS-Based Force-Detected Nuclear Magnetic Resonance (FDNMR) Spectrometer

NASA Technical Reports Server (NTRS)

Lee, Choonsup; Butler, Mark C.; Elgammal, Ramez A.; George, Thomas; Hunt, Brian; Weitekamp, Daniel P.

2006-01-01

Nuclear Magnetic Resonance (NMR) spectroscopy allows assignment of molecular structure by acquiring the energy spectrum of nuclear spins in a molecule, and by interpreting the symmetry and positions of resonance lines in the spectrum. As such, NMR has become one of the most versatile and ubiquitous spectroscopic methods. Despite these tremendous successes, NMR experiments suffer from inherent low sensitivity due to the relatively low energy of photons in the radio frequency (rt) region of the electromagnetic spectrum. Here, we describe a high-resolution spectroscopy in samples with diameters in the micron range and below. We have reported design and fabrication of force-detected nuclear magnetic resonance (FDNMR).

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

DTIC Science & Technology

2014-02-10

273.15 K to 373 K [15]. An optical analog of this, using infrared light to probe strain- free fiber Bragg gratings ( FBG ), exhibits temperature...sensors [9, 12, 13]. However, FBGs are susceptible to strain and are relatively large. Instead, we consider the use of ring resonators. In recent years...Traditionally, photonic thermometers such as those based on Fiber Bragg gratings ( FBG ) employ continuous wavelength scanning techniques to measure

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

NASA Astrophysics Data System (ADS)

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

2016-10-01

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

Photonic Feshbach resonance

NASA Astrophysics Data System (ADS)

Xu, Dazhi; Ian, Hou; Shi, Tao; Dong, Hui; Sun, Changpu

2010-07-01

Feshbach resonance is a resonance for two-atom scattering with two or more channels, in which a bound state is achieved in one channel. We show that this resonance phenomenon not only exists during the collisions of massive particles, but also emerges during the coherent transport of massless particles, that is, photons confined in the coupled resonator arrays linked by a separated cavity or a tunable two level system (TLS). When the TLS is coupled to one array to form a bound state in this setup, the vanishing transmission appears to display the photonic Feshbach resonance. This process can be realized through various experimentally feasible solid state systems, such as the couple defected cavities in photonic crystals and the superconducting qubit coupled to the transmission line. The numerical simulation based on the finite-different time-domain (FDTD) method confirms our assumption about the physical implementation.

Resonator design and performance estimation for a space-based laser transmitter

NASA Astrophysics Data System (ADS)

Agrawal, Lalita; Bhardwaj, Atul; Pal, Suranjan; Kamalakar, J. A.

2006-12-01

Development of a laser transmitter for space applications is a highly challenging task. The laser must be rugged, reliable, lightweight, compact and energy efficient. Most of these features are inherently achieved by diode pumping of solid state lasers. Overall system reliability can further be improved by appropriate optical design of the laser resonator besides selection of suitable electro-optical and opto-mechanical components. This paper presents the design details and the theoretically estimated performance of a crossed-porro prism based, folded Z-shaped laser resonator. A symmetrically pumped Nd: YAG laser rod of 3 mm diameter and 60 mm length is placed in the gain arm with total input peak power of 1800 W from laser diode arrays. Electro-optical Q-switching is achieved through a combination of a polarizer, a fractional waveplate and LiNbO 3 Q-switch crystal (9 x 9 x 25 mm) placed in the feedback arm. Polarization coupled output is obtained by optimizing azimuth angle of quarter wave plate placed in the gain arm. Theoretical estimation of laser output energy and pulse width has been carried out by varying input power levels and resonator length to analyse the performance tolerances. The designed system is capable of meeting the objective of generating laser pulses of 10 ns duration and 30 mJ energy @ 10 Hz.

Ultra-small v-shaped gold split ring resonators for biosensing using fundamental magnetic resonance in the visible spectrum

NASA Astrophysics Data System (ADS)

Mauluidy Soehartono, Alana; Mueller, Aaron David; Tobing, Landobasa Yosef Mario; Chan, Kok Ken; Zhang, Dao Hua; Yong, Ken-Tye

2017-10-01

Strong light localization within metal nanostructures occurs by collective oscillations of plasmons in the form of electric and magnetic resonances. This so-called localized surface plasmon resonance (LSPR) has gained much interest in the development of low-cost sensing platforms in the visible spectrum. However, demonstrations of LSPR-based sensing are mostly limited to electric resonances due to the technological limitations for achieving magnetic resonances in the visible spectrum. In this work, we report the first demonstration of LSPR sensing based on fundamental magnetic resonance in the visible spectrum using ultrasmall gold v-shaped split ring resonators. Specifically, we show the ability for detecting adsorption of bovine serum albumin and cytochrome c biomolecules at monolayer levels, and the selective binding of protein A/G to immunoglobulin G.

Design issues for directional coupler- and MMI-based optical microring resonator filters on InP

NASA Astrophysics Data System (ADS)

Themistos, Christos; Kalli, Kyriacos; Komodromos, Michalis; Rajarajan, Muttukrishnan; Rahman, B. M. A.; Grattan, Kenneth T. V.

2004-08-01

The characterization and optimization of optical microring resonator-based optical filters on deeply etched GaInAsP-Inp waveguides, using the finite element-based beam propagation approach is presented here. Design issues for directional coupler- and multimode interference coupler-based devices, such as field evolution, optical power, phase, fabrication tolerance and wavelength dependence have been investigated.

System and method for regulating resonant inverters

DOEpatents

Stevanovic, Ljubisa Dragoljub [Clifton Park, NY; Zane, Regan Andrew [Superior, CO

2007-08-28

A technique is provided for direct digital phase control of resonant inverters based on sensing of one or more parameters of the resonant inverter. The resonant inverter control system includes a switching circuit for applying power signals to the resonant inverter and a sensor for sensing one or more parameters of the resonant inverter. The one or more parameters are representative of a phase angle. The resonant inverter control system also includes a comparator for comparing the one or more parameters to a reference value and a digital controller for determining timing of the one or more parameters and for regulating operation of the switching circuit based upon the timing of the one or more parameters.

Advances in Magnetic Resonance Imaging of the Skull Base

PubMed Central

Kirsch, Claudia F.E.

2014-01-01

Introduction Over the past 20 years, magnetic resonance imaging (MRI) has advanced due to new techniques involving increased magnetic field strength and developments in coils and pulse sequences. These advances allow increased opportunity to delineate the complex skull base anatomy and may guide the diagnosis and treatment of the myriad of pathologies that can affect the skull base. Objectives The objective of this article is to provide a brief background of the development of MRI and illustrate advances in skull base imaging, including techniques that allow improved conspicuity, characterization, and correlative physiologic assessment of skull base pathologies. Data Synthesis Specific radiographic illustrations of increased skull base conspicuity including the lower cranial nerves, vessels, foramina, cerebrospinal fluid (CSF) leaks, and effacement of endolymph are provided. In addition, MRIs demonstrating characterization of skull base lesions, such as recurrent cholesteatoma versus granulation tissue or abscess versus tumor, are also provided as well as correlative clinical findings in CSF flow studies in a patient pre- and post-suboccipital decompression for a Chiari I malformation. Conclusions This article illustrates MRI radiographic advances over the past 20 years, which have improved clinicians' ability to diagnose, define, and hopefully improve the treatment and outcomes of patients with underlying skull base pathologies. PMID:25992137

Sound absorption by a Helmholtz resonator

NASA Astrophysics Data System (ADS)

Komkin, A. I.; Mironov, M. A.; Bykov, A. I.

2017-07-01

Absorption characteristics of a Helmholtz resonator positioned at the end wall of a circular duct are considered. The absorption coefficient of the resonator is experimentally investigated as a function of the diameter and length of the resonator neck and the depth of the resonator cavity. Based on experimental data, the linear analytic model of a Helmholtz resonator is verified, and the results of verification are used to determine the dissipative attached length of the resonator neck so as to provide the agreement between experimental and calculated data. Dependences of sound absorption by a Helmholtz resonator on its geometric parameters are obtained.

Tunable complex-valued multi-tap microwave photonic filter based on single silicon-on-insulator microring resonator.

PubMed

Lloret, Juan; Sancho, Juan; Pu, Minhao; Gasulla, Ivana; Yvind, Kresten; Sales, Salvador; Capmany, José

2011-06-20

A complex-valued multi-tap tunable microwave photonic filter based on single silicon-on-insulator microring resonator is presented. The degree of tunability of the approach involving two, three and four taps is theoretical and experimentally characterized, respectively. The constraints of exploiting the optical phase transfer function of a microring resonator aiming at implementing complex-valued multi-tap filtering schemes are also reported. The trade-off between the degree of tunability without changing the free spectral range and the number of taps is studied in-depth. Different window based scenarios are evaluated for improving the filter performance in terms of the side-lobe level.

Terahertz modulation based on surface plasmon resonance by self-gated graphene

NASA Astrophysics Data System (ADS)

Qian, Zhenhai; Yang, Dongxiao; Wang, Wei

2018-05-01

We theoretically and numerically investigate the extraordinary optical transmission through a terahertz metamaterial composed of metallic ring aperture arrays. The physical mechanism of different transmission peaks is elucidated to be magnetic polaritons or propagation surface plasmons with the help of surface current and electromagnetic field distributions at respective resonance frequencies. Then, we propose a high performance terahertz modulator based on the unique PSP resonance and combined with the metallic ring aperture arrays and a self-gated parallel-plate graphene capacitor. Because, to date, few researches have exhibited gate-controlled graphene modulation in terahertz region with low insertion losses, high modulation depth and low control voltage at room temperature. Here, we propose a 96% amplitude modulation with 0.7 dB insertion losses and ∼5.5 V gate voltage. Besides, we further study the absorption spectra of the modulator. When the transmission of modulator is very low, a 91% absorption can be achieved for avoiding damaging the source devices.

Anti resonant reflecting optical waveguide structure based on oxidized porous silicon for label free bio sensing applications

NASA Astrophysics Data System (ADS)

Haji, L.; Hiraoui, M.; Lorrain, N.; Guendouz, M.

2012-03-01

In this letter we report on the use of an electrochemical process for the fabrication of anti resonant reflecting optical waveguide based on oxidized porous silicon. This method is known to allow the formation of various photonic structures (Bragg mirror, microcavity), thanks to the easy and in situ modulation of the porosity and thus of the refractive index. Planar anti resonant reflecting optical waveguide structure made from porous silicon is demonstrated to be very effective for low losses as compared to conventional resonant waveguide. Optical measurements carried out for TE and TM polarizations are reported and related to optical sensing.

Is a Trineutron Resonance Lower in Energy than a Tetraneutron Resonance?

NASA Astrophysics Data System (ADS)

Gandolfi, S.; Hammer, H.-W.; Klos, P.; Lynn, J. E.; Schwenk, A.

2017-06-01

We present quantum Monte Carlo calculations of few-neutron systems confined in external potentials based on local chiral interactions at next-to-next-to-leading order in chiral effective field theory. The energy and radial densities for these systems are calculated in different external Woods-Saxon potentials. We assume that their extrapolation to zero external-potential depth provides a quantitative estimate of three- and four-neutron resonances. The validity of this assumption is demonstrated by benchmarking with an exact diagonalization in the two-body case. We find that the extrapolated trineutron resonance, as well as the energy for shallow well depths, is lower than the tetraneutron resonance energy. This suggests that a three-neutron resonance exists below a four-neutron resonance in nature and is potentially measurable. To confirm that the relative ordering of three- and four-neutron resonances is not an artifact of the external confinement, we test that the odd-even staggering in the helium isotopic chain is reproduced within this approach. Finally, we discuss similarities between our results and ultracold Fermi gases.

Is a Trineutron Resonance Lower in Energy than a Tetraneutron Resonance?

DOE PAGES

Gandolfi, Stefano; Hammer, Hans -Werner; Klos, P.; ...

2017-06-08

Here, we present quantum Monte Carlo calculations of few-neutron systems confined in external potentials based on local chiral interactions at next-to-next-to-leading order in chiral effective field theory. The energy and radial densities for these systems are calculated in different external Woods-Saxon potentials. We assume that their extrapolation to zero external-potential depth provides a quantitative estimate of three- and four-neutron resonances. The validity of this assumption is demonstrated by benchmarking with an exact diagonalization in the two-body case. We find that the extrapolated trineutron resonance, as well as the energy for shallow well depths, is lower than the tetraneutron resonance energy.more » This suggests that a three-neutron resonance exists below a four-neutron resonance in nature and is potentially measurable. To confirm that the relative ordering of three- and four-neutron resonances is not an artifact of the external confinement, we test that the odd-even staggering in the helium isotopic chain is reproduced within this approach. Finally, we discuss similarities between our results and ultracold Fermi gases.« less

Micro-resonators based on integrated polymer technology for optical sensing

NASA Astrophysics Data System (ADS)

Girault, Pauline; Lemaitre, Jonathan; Guendouz, Mohammed; Lorrain, Nathalie; Poffo, Luiz; Gadonna, Michel; Bosc, Dominique

2014-05-01

Research on sensors has experienced a noticeable development over the last decades especially in label free optical biosensors. However, compact sensors without markers for rapid, reliable and inexpensive detection of various substances induce a significant research of new technological solutions. The context of this work is the development of a sensor based on easily integrated and inexpensive micro-resonator (MR) component in integrated optics, highly sensitive and selective mainly in the areas of health and food. In this work, we take advantage of our previous studies on filters based on micro-resonators (MR) to experiment a new couple of polymers in the objective to use MR as a sensing function. MRs have been fabricated by processing SU8 polymer as core and PMATRIFE polymer as cladding layer of the waveguide. The refractive index contrast reaches 0.16 @ 1550 nm. Sub-micronic ring waveguides gaps from 0.5 to 1 μm have been successfully achieved with UV (i-line) photolithography. This work confirms our forecasts, published earlier, about the resolution that can be achieved. First results show a good extinction coefficient of ~17 dB, a quality factor around 104 and a finesse of 12. These results are in concordance with the theoretical study and they allow us to validate our technology with this couple of polymers. Work is going on with others lower cladding materials that will be used to further increase refractive index contrast for sensing applications.

Design and Characterization of a Novel Bio-inspired Hair Flow Sensor Based on Resonant Sensing

NASA Astrophysics Data System (ADS)

Guo, X.; Yang, B.; Wang, Q. H.; Lu, C. F.; Hu, D.

2018-03-01

Flow sensors inspired by the natural hair sensing mechanism have great prospect in the research of micro-autonomous system and technology (MAST) for the three-dimensional structure characteristics with high spatial and quality utilization. A novel bio-inspired hair flow sensor (BHFS) based on resonant sensing with a unique asymmetric design is presented in this paper. A hair transducer and a signal detector which is constituted of a two-stage micro-leverage mechanism and two symmetrical resonators (double ended tuning fork, DETF) are adopted to realize the high sensitivity to air flow. The sensitivity of the proposed BHFS is improved significantly than the published ones due to the high sensitivity of resonators and the higher amplification factor possessed by the two-stage micro-leverage mechanism. The standard deep dry silicon on glass (DDSOG) process is chosen to fabricate the proposed BHFS. The experiment result demonstrates that the fabricated BHFS has a mechanical sensitivity of 5.26 Hz/(m/s)2 at a resonant frequency of 22 kHz with the hair height of 6 mm.

Development of optical micro resonance based sensor for detection and identification of microparticles and biological agents

NASA Astrophysics Data System (ADS)

Saetchnikov, Vladimir A.; Tcherniavskaia, Elina A.; Schweiger, Gustav

2009-05-01

A novel emerging technique for the label-free analysis of nanoparticles including biomolecules using optical micro cavity resonance of whispering-gallery-type modes is being developed. Schemes of such a method based on microsphere melted by laser on the tip of a standard single mode fiber optical cable with a laser and free microsphere matrix have been developed. Using a calibration principal of ultra high resolution spectroscopy based on such a scheme the method is being transformed to make further development for microbial application. The sensitivity of developed schemes has been tested to refractive index changes by monitoring the magnitude of the whispering gallery modes spectral shift. Water solutions of ethanol, glucose, vitamin C and biotin have been used. Some other schemes using similar principals: stand-alone, array and matrix microsphere resonators, liquid core optical ring resonators are also being under development. The influences of the gap in whispering-gallery modes on energy coupling, resonance quality and frequency have been investigated. An optimum gap for sensing applications has been defined at the half maximum energy coupling where both the Q factor and coupling efficiency are high and the resonance frequency is little affected by the gap variation. Developed schemes have been demonstrated to be a promising technology platform for sensitive, lab-on-chip type sensor which can be used for development of diagnostic tools for different biological molecules, e.g. proteins, oligonucleotides, oligosaccharides, lipids, small molecules, viral particles, cells as well as in different experimental contexts e.g. proteomics, genomics, drug discovery, and membrane studies.

Modelling of optoelectronic circuits based on resonant tunneling diodes

NASA Astrophysics Data System (ADS)

Rei, João. F. M.; Foot, James A.; Rodrigues, Gil C.; Figueiredo, José M. L.

2017-08-01

Resonant tunneling diodes (RTDs) are the fastest pure electronic semiconductor devices at room temperature. When integrated with optoelectronic devices they can give rise to new devices with novel functionalities due to their highly nonlinear properties and electrical gain, with potential applications in future ultra-wide-band communication systems (see e.g. EU H2020 iBROW Project). The recent coverage on these devices led to the need to have appropriated simulation tools. In this work, we present RTD based optoelectronic circuits simulation packages to provide circuit signal level analysis such as transient and frequency responses. We will present and discuss the models, and evaluate the simulation packages.

Integrated unaligned resonant modulator tuning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zortman, William A.; Lentine, Anthony L.

Methods and systems for tuning a resonant modulator are disclosed. One method includes receiving a carrier signal modulated by the resonant modulator with a stream of data having an approximately equal number of high and low bits, determining an average power of the modulated carrier signal, comparing the average power to a predetermined threshold, and operating a tuning device coupled to the resonant modulator based on the comparison of the average power and the predetermined threshold. One system includes an input structure, a plurality of processing elements, and a digital control element. The input structure is configured to receive, frommore » the resonant modulator, a modulated carrier signal. The plurality of processing elements are configured to determine an average power of the modulated carrier signal. The digital control element is configured to operate a tuning device coupled to the resonant modulator based on the average power of the modulated carrier signal.« less

Gadolinium-based magnetic resonance imaging contrast agents in interventional radiology.

PubMed

Atar, Eli

2004-07-01

Gadolinium-based agents are widely used in magnetic resonance imaging as contrast agents. These agents are radio-opaque enough for diagnostic imaging of the vascular tree by using digitally subtracted images as well as for imaging of the biliary system and the urinary tract. The recommended doses for gadolinium do not impair renal function or cause adverse reactions in patients with iodine sensitivity; thus patients with such conditions can safely undergo diagnostic angiography, either by MRI angiography or by catheterization using gadolinium as contrast agent, for diagnostic and therapeutic purposes.

Magnetic Resonance Imaging Targeted Biopsy Improves Selection of Patients Considered for Active Surveillance for Clinically Low Risk Prostate Cancer Based on Systematic Biopsies.

PubMed

Ouzzane, Adil; Renard-Penna, Raphaele; Marliere, François; Mozer, Pierre; Olivier, Jonathan; Barkatz, Johann; Puech, Philippe; Villers, Arnauld

2015-08-01

Current selection criteria for active surveillance based on systematic biopsy underestimate prostate cancer volume and grade. We investigated the role of additional magnetic resonance imaging targeted biopsy in reclassifying patients eligible for active surveillance based on systematic biopsy. We performed a study at 2 institutions in a total of 281 men with increased prostate specific antigen. All men met certain criteria, including 1) prebiopsy magnetic resonance imaging, 12-core transrectal systematic biopsy and 2 additional magnetic resonance imaging targeted biopsies of lesions suspicious for cancer during the same sequence as systematic biopsy, and 2) eligibility for active surveillance based on systematic biopsy results. Criteria for active surveillance were prostate specific antigen less than 10 ng/ml, no Gleason grade 4/5, 5 mm or less involvement of any biopsy core and 2 or fewer positive systematic biopsy cores. Patient characteristics were compared between reclassified and nonreclassified groups based on magnetic resonance imaging targeted biopsy results. On magnetic resonance imaging 58% of the 281 patients had suspicious lesions. Magnetic resonance imaging targeted biopsy was positive for cancer in 81 of 163 patients (50%). Of 281 patients 28 (10%) were reclassified by magnetic resonance imaging targeted biopsy as ineligible for active surveillance based on Gleason score in 8, cancer length in 20 and Gleason score plus cancer length in 9. Suspicious areas on magnetic resonance imaging were in the anterior part of the prostate in 15 of the 28 men (54%). Reclassified patients had a smaller prostate volume (37 vs 52 cc) and were older (66.5 vs 63 years) than those who were not reclassified (p < 0.05). Magnetic resonance imaging targeted biopsy reclassified 10% of patients who were eligible for active surveillance based on systematic biopsy. Its incorporation into the active surveillance eligibility criteria may decrease the risk of reclassification to

Tunable resonance-domain diffraction gratings based on electrostrictive polymers.

PubMed

Axelrod, Ramon; Shacham-Diamand, Yosi; Golub, Michael A

2017-03-01

Critical combination of high diffraction efficiency and large diffraction angles can be delivered by resonance-domain diffractive optics with high aspect ratio and wavelength-scale grating periods. To advance from static to electrically tunable resonance-domain diffraction grating, we resorted to its replication onto 2-5 μm thick P(VDF-TrFE-CFE) electrostrictive ter-polymer membranes. Electromechanical and optical computer simulations provided higher than 90% diffraction efficiency, a large continuous deflection range exceeding 20°, and capabilities for adiabatic spatial modulation of the grating period and slant. A prototype of the tunable resonance-domain diffraction grating was fabricated in a soft-stamp thermal nanoimprinting process, characterized, optically tested, and provided experimental feasibility proof for the tunable sub-micron-period gratings on electrostrictive polymers.

Thermal response of chalcogenide microsphere resonators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahmad, H; Aryanfar, I; Lim, K S

2012-05-31

A chalcogenide microsphere resonator (CMR) used for temperature sensing is proposed and demonstrated. The CMR is fabricated using a simple technique of heating chalcogenide glass and allowing the molten glass to form a microsphere on the waist of a tapered silica fibre. The thermal responses of the CMR is investigated and compared to that of a single-mode-fibre (SMF) based microsphere resonator. It is observed that the CMR sensitivity to ambient temperature changes is 8 times higher than that of the SMF-based microsphere resonator. Heating the chalcogenide microsphere with a laser beam periodically turned on and off shows periodic shifts inmore » the transmission spectrum of the resonator. By injecting an intensity-modulated cw signal through the resonator a thermal relaxation time of 55 ms is estimated.« less

Templated assembly of albumin-based nanoparticles for simultaneous gene silencing and magnetic resonance imaging

NASA Astrophysics Data System (ADS)

Mertz, Damien; Affolter-Zbaraszczuk, Christine; Barthès, Julien; Cui, Jiwei; Caruso, Frank; Baumert, Thomas F.; Voegel, Jean-Claude; Ogier, Joelle; Meyer, Florent

2014-09-01

In this article, we address the design of innovative human serum albumin (HSA)-based nanoparticles loaded with silencing RNA and grafted with gadolinium complexes having average sizes ranging from ca. 50 to 150 nm according to the siRNA/HSA composition. The non-covalent siRNA/HSA assembly is formed on isobutyramide-modified mesoporous silica and the self-supported HSA-based nanoparticles are obtained following the silica template dissolution. These original protein particles provide simultaneous magnetic resonance imaging contrast enhancement and cellular in vitro gene silencing.In this article, we address the design of innovative human serum albumin (HSA)-based nanoparticles loaded with silencing RNA and grafted with gadolinium complexes having average sizes ranging from ca. 50 to 150 nm according to the siRNA/HSA composition. The non-covalent siRNA/HSA assembly is formed on isobutyramide-modified mesoporous silica and the self-supported HSA-based nanoparticles are obtained following the silica template dissolution. These original protein particles provide simultaneous magnetic resonance imaging contrast enhancement and cellular in vitro gene silencing. Electronic supplementary information (ESI) available: Experimental details and supporting Fig. S1-S4. See DOI: 10.1039/c4nr02623c

Ultralow-phase-noise oscillators based on BAW resonators.

PubMed

Li, Mingdong; Seok, Seonho; Rolland, Nathalie; Rolland, Paul; El Aabbaoui, Hassan; de Foucauld, Emeric; Vincent, Pierre; Giordano, Vincent

2014-06-01

This paper presents two 2.1-GHz low-phase noise oscillators based on BAW resonators. Both a single-ended common base structure and a differential Colpitts structure have been implemented in a 0.25-μm BiCMOS process. The detailed design methods including the realization, optimization, and test are reported. The differential Colpitts structure exhibits a phase noise 6.5 dB lower than the single-ended structure because of its good performance of power noise immunity. Comparison between the two structures is also carried out. The differential Colpitts structure shows a phase noise level of -87 dBc/Hz at 1-kHz offset frequency and a phase noise floor of -162 dBc/Hz, with an output power close to -6.5 dBm and a core consumption of 21.6 mW. Furthermore, with the proposed optimization methods, both proposed devices have achieved promising phase noise performance compared with state-of-the-art oscillators described in the literature. Finally, we briefly present the application of the proposed BAW oscillator to a micro-atomic clock.

Stochastic resonance-enhanced laser-based particle detector.

PubMed

Dutta, A; Werner, C

2009-01-01

This paper presents a Laser-based particle detector whose response was enhanced by modulating the Laser diode with a white-noise generator. A Laser sheet was generated to cast a shadow of the object on a 200 dots per inch, 512 x 1 pixels linear sensor array. The Laser diode was modulated with a white-noise generator to achieve stochastic resonance. The white-noise generator essentially amplified the wide-bandwidth (several hundred MHz) noise produced by a reverse-biased zener diode operating in junction-breakdown mode. The gain in the amplifier in the white-noise generator was set such that the Receiver Operating Characteristics plot provided the best discriminability. A monofiber 40 AWG (approximately 80 microm) wire was detected with approximately 88% True Positive rate and approximately 19% False Positive rate in presence of white-noise modulation and with approximately 71% True Positive rate and approximately 15% False Positive rate in absence of white-noise modulation.

Sensing performance analysis on Fano resonance of metallic double-baffle contained MDM waveguide coupled ring resonator

NASA Astrophysics Data System (ADS)

Chen, Ying; Luo, Pei; Liu, Xiaofei; Di, Yuanjian; Han, Shuaitao; Cui, Xingning; He, Lei

2018-05-01

Based on the transmission property and the photon localization characteristic of the surface plasmonic sub-wavelength structure, a metallic double-baffle contained metal-dielectric-metal (MDM) waveguide coupled ring resonator is proposed. Like the electromagnetically induced transparency (EIT), the Fano resonance can be achieved by the interference between the metallic double-baffle resonator and the ring resonator. Based on the coupled mode theory, the transmission property is analyzed. Through the numerical simulation by the finite element method (FEM), the quantitative analysis on the influences of the radius R of the ring and the coupling distance g between the metallic double-baffle resonator and the ring resonator for the figure of merit (FOM) is performed. And after the structure parameter optimization, the sensing performance of the waveguide structure is discussed. The simulation results show that the FOM value of the optimized structure can attain to 5.74 ×104 and the sensitivity of resonance wavelength with refractive index drift is about 825 nm/RIU. The range of the detected refractive index is suitable for all gases. The waveguide structure can provide effective theoretical references for the design of integrated plasmonic devices.

Spin Resonance in the New-Structure-Type Iron-Based Superconductor CaKFe4As4

NASA Astrophysics Data System (ADS)

Iida, Kazuki; Ishikado, Motoyuki; Nagai, Yuki; Yoshida, Hiroyuki; Christianson, Andrew D.; Murai, Naoki; Kawashima, Kenji; Yoshida, Yoshiyuki; Eisaki, Hiroshi; Iyo, Akira

2017-09-01

The dynamical spin susceptibility in the new-structure-type iron-based superconductor CaKFe4As4 was investigated by using a combination of inelastic neutron scattering (INS) measurements and random phase approximation (RPA) calculations. Powder INS measurements show that the spin resonance at Qres = 1.17(1) Å-1, corresponding to the (π ,π ) nesting wave vector in tetragonal notation, evolves below Tc. The characteristic energy of the spin resonance Eres = 12.5 meV is smaller than twice the size of the superconducting gap (2Δ). The broad energy feature of the dynamical susceptibility of the spin resonance can be explained by the RPA calculations, in which the different superconducting gaps on different Fermi surfaces are taken into account. Our INS and PRA studies demonstrate that the superconducting pairing nature in CaKFe4As4 is the s± symmetry.

Optical fiber endface biosensor based on resonances in dielectric waveguide gratings

NASA Astrophysics Data System (ADS)

Wawro, Debra D.; Tibuleac, Sorin; Magnusson, Robert; Liu, Hanli

2000-05-01

A new fiber optic sensor integrating dielectric diffraction gratings and thin films on optical fiber endfaces is prosed for biomedical sensing applications. This device utilizes a resonant dielectric waveguide grating structure fabricated on an optical fiber endface to probe reactions occurring in a sensing layer deposited on its surface. The operation of this sensor is based upon a fundamental resonance effect that occurs in waveguide gratings. An incident broad- spectrum signal is guided within an optical fiber and is filtered to reflect or transmit a desired spectral band by the diffractive thin film structure on its endface. Slight changes in one or more parameters of the waveguide grating, such as refractive index or thickness, can result in a responsive shift of the reflected or transmitted spectral peak that can be detected with spectroscopic instruments. This new sensor concept combines improved sensitivity and accuracy with attractive features found separately in currently available fiber optic sensors, such as large dynamic range, small sensing proximity, real time operation, and remote sensing. Diffractive elements of this type consisting of a photoresist grating on a Si3N4 waveguide have been fabricated on multimode optical fiber endfaces with 100 micrometers cores. Preliminary experimental tests using a tunable Ti:sapphire laser indicate notches of 18 percent in the transmission spectrum of the fiber endface guided-mode resonance devices. A theoretical analysis of the device performance capabilities is presented and applied to evaluate the feasibility and potential advantages of this bioprobe.

Nonlinear absorption of Sb-based phase change materials due to the weakening of the resonant bond

NASA Astrophysics Data System (ADS)

Liu, Shuang; Wei, Jingsong; Gan, Fuxi

2012-03-01

The current study proposes a model based on the weakening of the resonant bond to explore the giant optical nonlinear saturable absorption of Sb-based phase change materials. In order to analyze the weakening of resonant bond effectively, we take the Sb2Te3 as an example. First-principle calculations show that both the Born effective charge and optical dielectric constant of crystalline Sb2Te3 in the 300 K to 500 K temperature range monotonically decrease with the temperature, indicating a weakening of the resonant bond. This weakening induces a decline in the absorption coefficient at a rate of 103 m-1 K-1, which results in a nonlinear saturable absorption coefficient in the order of 10-2 m/W. The nonlinear absorption characteristics of the crystalline Sb, Sb7Te3, and Sb2Te3 thin films at 405 nm laser wavelength are measured via z-scan technique using nanosecond laser pulses to validate the above-proposed model. The experimental results are in good agreement with theoretical prediction.

Quasi-distributed and wavelength selective addressing of optical micro-resonators based on long period fiber gratings.

PubMed

Farnesi, D; Chiavaioli, F; Baldini, F; Righini, G C; Soria, S; Trono, C; Conti, G Nunzi

2015-08-10

A novel all-in-fiber method for coupling light to high-Q silica whispering gallery mode (WGM) optical micro-resonators is presented, which is based on a pair of long period fiber gratings (LPGs) written in the same silica fiber, along with a thick fiber taper (15-18 μm in waist) in between the LPGs. The proposed coupling structure is robust and can be replicated many times along the same fiber simply cascading LPGs with different bands. Typical Q-factors of the order of 10(8) and total coupling efficiency up to 60% were measured collecting the resonances of microspheres or microbubbles at the fiber end. This approach uniquely allows quasi-distributed and wavelength selective addressing of different micro-resonators along the same fiber.

Nonlinear behaviour of cantilevered carbon nanotube resonators based on a new nonlinear electrostatic load model

NASA Astrophysics Data System (ADS)

Farokhi, Hamed; Païdoussis, Michael P.; Misra, Arun K.

2018-04-01

The present study examines the nonlinear behaviour of a cantilevered carbon nanotube (CNT) resonator and its mass detection sensitivity, employing a new nonlinear electrostatic load model. More specifically, a 3D finite element model is developed in order to obtain the electrostatic load distribution on cantilevered CNT resonators. A new nonlinear electrostatic load model is then proposed accounting for the end effects due to finite length. Additionally, a new nonlinear size-dependent continuum model is developed for the cantilevered CNT resonator, employing the modified couple stress theory (to account for size-effects) together with the Kelvin-Voigt model (to account for nonlinear damping); the size-dependent model takes into account all sources of nonlinearity, i.e. geometrical and inertial nonlinearities as well as nonlinearities associated with damping, small-scale, and electrostatic load. The nonlinear equation of motion of the cantilevered CNT resonator is obtained based on the new models developed for the CNT resonator and the electrostatic load. The Galerkin method is then applied to the nonlinear equation of motion, resulting in a set of nonlinear ordinary differential equations, consisting of geometrical, inertial, electrical, damping, and size-dependent nonlinear terms. This high-dimensional nonlinear discretized model is solved numerically utilizing the pseudo-arclength continuation technique. The nonlinear static and dynamic responses of the system are examined for various cases, investigating the effect of DC and AC voltages, length-scale parameter, nonlinear damping, and electrostatic load. Moreover, the mass detection sensitivity of the system is examined for possible application of the CNT resonator as a nanosensor.

Versatile infrared refractive-index sensor based on surface plasmon resonance in graphene sheet

NASA Astrophysics Data System (ADS)

Bai, Yukun; Wang, Biao; Ma, Xiurong

2018-03-01

A reflection-type refractive-index sensor based on the surface plasmon resonance of graphene in the mid-infrared to terahertz regime is proposed. With a simple configuration, the sensor demonstrates high flexibilities for the gas and liquid samples sensing and achieves markedly improved figures of merit of 53.64 and 36.5 RIU - 1, respectively.

Investigation of the effects of metal-wire resonators in sub-wavelength array based on time-reversal technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tu, Hui-Lin, E-mail: tuhl-uestc@163.com, E-mail: xiaoshaoqiu@uestc.edu.cn; Xiao, Shao-Qiu, E-mail: tuhl-uestc@163.com, E-mail: xiaoshaoqiu@uestc.edu.cn

The resonant metalens consisting of metal-wire resonators with equally finite length can break the diffraction barrier well suited for super-resolution imaging. In this study, a basic combination constructed by two metal-wire resonators with different lengths is proposed, and its resonant characteristics is analyzed using the method of moments (MoM). Based on the time reversal (TR) technique, this kind of combination can be applied to a sub-wavelength two-element antenna array with a 1/40-wavelength interval to make the elements work simultaneously with little interference in the frequency band of 1.0-1.5 GHz and 1.5-2.0 GHz, respectively. The simulations and experiments show that analysismore » of MoM and the application of the resonators can be used to design multi-frequency sub-wavelength antenna arrays efficiently. This general design method is convenient and can be used for many applications, such as weakening jamming effectiveness in communication systems, and sub-wavelength imaging in a broad frequency band.« less

Orbital resonances around black holes.

PubMed

Brink, Jeandrew; Geyer, Marisa; Hinderer, Tanja

2015-02-27

We compute the length and time scales associated with resonant orbits around Kerr black holes for all orbital and spin parameters. Resonance-induced effects are potentially observable when the Event Horizon Telescope resolves the inner structure of Sgr A*, when space-based gravitational wave detectors record phase shifts in the waveform during the resonant passage of a compact object spiraling into the black hole, or in the frequencies of quasiperiodic oscillations for accreting black holes. The onset of geodesic chaos for non-Kerr spacetimes should occur at the resonance locations quantified here.

DEMARCATE: Density-based magnetic resonance image clustering for assessing tumor heterogeneity in cancer.

PubMed

Saha, Abhijoy; Banerjee, Sayantan; Kurtek, Sebastian; Narang, Shivali; Lee, Joonsang; Rao, Ganesh; Martinez, Juan; Bharath, Karthik; Rao, Arvind U K; Baladandayuthapani, Veerabhadran

2016-01-01

Tumor heterogeneity is a crucial area of cancer research wherein inter- and intra-tumor differences are investigated to assess and monitor disease development and progression, especially in cancer. The proliferation of imaging and linked genomic data has enabled us to evaluate tumor heterogeneity on multiple levels. In this work, we examine magnetic resonance imaging (MRI) in patients with brain cancer to assess image-based tumor heterogeneity. Standard approaches to this problem use scalar summary measures (e.g., intensity-based histogram statistics) that do not adequately capture the complete and finer scale information in the voxel-level data. In this paper, we introduce a novel technique, DEMARCATE (DEnsity-based MAgnetic Resonance image Clustering for Assessing Tumor hEterogeneity) to explore the entire tumor heterogeneity density profiles (THDPs) obtained from the full tumor voxel space. THDPs are smoothed representations of the probability density function of the tumor images. We develop tools for analyzing such objects under the Fisher-Rao Riemannian framework that allows us to construct metrics for THDP comparisons across patients, which can be used in conjunction with standard clustering approaches. Our analyses of The Cancer Genome Atlas (TCGA) based Glioblastoma dataset reveal two significant clusters of patients with marked differences in tumor morphology, genomic characteristics and prognostic clinical outcomes. In addition, we see enrichment of image-based clusters with known molecular subtypes of glioblastoma multiforme, which further validates our representation of tumor heterogeneity and subsequent clustering techniques.

Microscopic approach based on a multiscale algebraic version of the resonating group model for radiative capture reactions

NASA Astrophysics Data System (ADS)

Solovyev, Alexander S.; Igashov, Sergey Yu.

2017-12-01

A microscopic approach to description of radiative capture reactions based on a multiscale algebraic version of the resonating group model is developed. The main idea of the approach is to expand wave functions of discrete spectrum and continuum for a nuclear system over different bases of the algebraic version of the resonating group model. These bases differ from each other by values of oscillator radius playing a role of scale parameter. This allows us in a unified way to calculate total and partial cross sections (astrophysical S factors) as well as branching ratio for the radiative capture reaction, to describe phase shifts for the colliding nuclei in the initial channel of the reaction, and at the same time to reproduce breakup thresholds of the final nucleus. The approach is applied to the theoretical study of the mirror 3H(α ,γ )7Li and 3He(α ,γ )7Be reactions, which are of great interest to nuclear astrophysics. The calculated results are compared with existing experimental data and with our previous calculations in the framework of the single-scale algebraic version of the resonating group model.

Passive Wearable Skin Patch Sensor Measures Limb Hemodynamics Based on Electromagnetic Resonance.

PubMed

Cluff, Kim; Becker, Ryan; Jayakumar, Balakumar; Han, Kiyun; Condon, Ernie; Dudley, Kenneth; Szatkowski, George; Pipinos, Iraklis I; Amick, Ryan Z; Patterson, Jeremy

2018-04-01

The objectives of this study were to design and develop an open-circuit electromagnetic resonant skin patch sensor, characterize the fluid volume and resonant frequency relationship, and investigate the sensor's ability to measure limb hemodynamics and pulse volume waveform features. The skin patch was designed from an open-circuit electromagnetic resonant sensor comprised of a single baseline trace of copper configured into a square planar spiral which had a self-resonating response when excited by an external radio frequency sweep. Using a human arm phantom with a realistic vascular network, the sensor's performance to measure limb hemodynamics was evaluated. The sensor was able to measure pulsatile blood flow which registered as shifts in the sensor's resonant frequencies. The time-varying waveform pattern of the resonant frequency displayed a systolic upstroke, a systolic peak, a dicrotic notch, and a diastolic down stroke. The resonant frequency waveform features and peak systolic time were validated against ultrasound pulse wave Doppler. A statistical correlation analysis revealed a strong correlation () between the resonant sensor peak systolic time and the pulse wave Doppler peak systolic time. The sensor was able to detect pulsatile flow, identify hemodynamic waveform features, and measure heart rate with 98% accuracy. The open-circuit resonant sensor design leverages the architecture of a thin planar spiral which is passive (does not require batteries), robust and lightweight (does not have electrical components or electrical connections), and may be able to wirelessly monitor cardiovascular health and limb hemodynamics.

Nonlinear dynamics under varying temperature conditions of the resonating beams of a differential resonant accelerometer

NASA Astrophysics Data System (ADS)

Zhang, Jing; Wang, Yagang; Zega, Valentina; Su, Yan; Corigliano, Alberto

2018-07-01

In this work the nonlinear dynamic behaviour under varying temperature conditions of the resonating beams of a differential resonant accelerometer is studied from the theoretical, numerical and experimental points of view. A complete analytical model based on the Hamilton’s principle is proposed to describe the nonlinear behaviour of the resonators under varying temperature conditions and numerical solutions are presented in comparison with experimental data. This provides a novel perspective to examine the relationship between temperature and nonlinearity, which helps predicting the dynamic behaviour of resonant devices and can guide their optimal design.

All-dielectric metamaterial frequency selective surface based on spatial arrangement ceramic resonators

NASA Astrophysics Data System (ADS)

Li, Liyang; Wang, Jun; Feng, Mingde; Ma, Hua; Wang, Jiafu; Du, Hongliang; Qu, Shaobo

In this paper, we demonstrate a method of designing all-dielectric metamaterial frequency selective surface (FSS) with ceramic resonators in spatial arrangement. Compared with the traditional way, spatial arrangement provides a flexible way to handle the permutation and combination of different ceramic resonators. With this method, the resonance response can be adjusted easily to achieve pass/stop band effects. As an example, a stop band spatial arrangement all-dielectric metamaterial FSS is designed. Its working band is in 11.65-12.23GHz. By adjusting permittivity and geometrical parameters of ceramic resonators, we can easily modulate the resonances, band pass or band stop characteristic, as well as the working band.

Terahertz quantum cascade lasers based on resonant phonon scattering for depopulation.

PubMed

Hu, Qing; Williams, Benjamin S; Kumar, Sushil; Callebaut, Hans; Reno, John L

2004-02-15

We report our development of terahertz (THz) quantum cascade lasers (QCLs), in which the depopulation of the lower radiative level is achieved through resonant longitudinal optical (LO) phonon scattering. This depopulation mechanism, similar to that implemented in all the QCLs operating at mid-infrared frequencies, is robust at high temperatures and high injection levels. The unique feature of resonant LO-phonon scattering in our THz QCL structures allows a highly selective depopulation of the lower radiative level with a sub-picosecond lifetime, while maintaining a relatively long upper level lifetime (more than 5 ps) that is due to upper-to-ground-state scattering. The first QCL based on this mechanism achieved lasing at 3.4 THz (lambda approximately 87 microm) up to 87 K for pulsed operations, with peak power levels exceeding 10 mW at ca. 40 K. Using a novel double-sided metal waveguide for mode confinement, which yields a unity mode confinement factor and therefore a low total cavity loss at THz frequencies, we have also achieved lasing at wavelengths longer than 100 microm.

Mid-infrared ultra-high-Q resonators based on fluoride crystalline materials

NASA Astrophysics Data System (ADS)

Lecaplain, C.; Javerzac-Galy, C.; Gorodetsky, M. L.; Kippenberg, T. J.

2016-11-01

The unavailability of highly transparent materials in the mid-infrared has been the main limitation in the development of ultra-sensitive molecular sensors or cavity-based spectroscopy applications. Whispering gallery mode microresonators have attained ultra-high-quality (Q) factor resonances in the near-infrared and visible. Here we report ultra-high Q factors in the mid-infrared using polished alkaline earth metal fluoride crystals. Using an uncoated chalcogenide tapered fibre as a high-ideality coupler in the mid-infrared, we study via cavity ringdown technique the losses of BaF2, CaF2, MgF2 and SrF2 microresonators. We show that MgF2 is limited by multiphonon absorption by studying the temperature dependence of the Q factor. In contrast, in SrF2 and BaF2 the lower multiphonon absorption leads to ultra-high Q factors at 4.5 μm. These values correspond to an optical finesse of , the highest value achieved for any type of mid-infrared resonator to date.

Mid-infrared ultra-high-Q resonators based on fluoride crystalline materials

PubMed Central

Lecaplain, C.; Javerzac-Galy, C.; Gorodetsky, M. L.; Kippenberg, T. J.

2016-01-01

The unavailability of highly transparent materials in the mid-infrared has been the main limitation in the development of ultra-sensitive molecular sensors or cavity-based spectroscopy applications. Whispering gallery mode microresonators have attained ultra-high-quality (Q) factor resonances in the near-infrared and visible. Here we report ultra-high Q factors in the mid-infrared using polished alkaline earth metal fluoride crystals. Using an uncoated chalcogenide tapered fibre as a high-ideality coupler in the mid-infrared, we study via cavity ringdown technique the losses of BaF2, CaF2, MgF2 and SrF2 microresonators. We show that MgF2 is limited by multiphonon absorption by studying the temperature dependence of the Q factor. In contrast, in SrF2 and BaF2 the lower multiphonon absorption leads to ultra-high Q factors at 4.5 μm. These values correspond to an optical finesse of , the highest value achieved for any type of mid-infrared resonator to date. PMID:27869119

Mid-infrared ultra-high-Q resonators based on fluoride crystalline materials.

PubMed

Lecaplain, C; Javerzac-Galy, C; Gorodetsky, M L; Kippenberg, T J

2016-11-21

The unavailability of highly transparent materials in the mid-infrared has been the main limitation in the development of ultra-sensitive molecular sensors or cavity-based spectroscopy applications. Whispering gallery mode microresonators have attained ultra-high-quality (Q) factor resonances in the near-infrared and visible. Here we report ultra-high Q factors in the mid-infrared using polished alkaline earth metal fluoride crystals. Using an uncoated chalcogenide tapered fibre as a high-ideality coupler in the mid-infrared, we study via cavity ringdown technique the losses of BaF 2 , CaF 2 , MgF 2 and SrF 2 microresonators. We show that MgF 2 is limited by multiphonon absorption by studying the temperature dependence of the Q factor. In contrast, in SrF 2 and BaF 2 the lower multiphonon absorption leads to ultra-high Q factors at 4.5 μm. These values correspond to an optical finesse of , the highest value achieved for any type of mid-infrared resonator to date.

Blade resonance parameter identification based on tip-timing method without the once-per revolution sensor

NASA Astrophysics Data System (ADS)

Guo, Haotian; Duan, Fajie; Zhang, Jilong

2016-01-01

Blade tip-timing is the most effective method for blade vibration online measurement of turbomachinery. In this article a synchronous resonance vibration measurement method of blade based on tip-timing is presented. This method requires no once-per revolution sensor which makes it more generally applicable in the condition where this sensor is difficult to install, especially for the high-pressure rotors of dual-rotor engines. Only three casing mounted probes are required to identify the engine order, amplitude, natural frequency and the damping coefficient of the blade. A method is developed to identify the blade which a tip-timing data belongs to without once-per revolution sensor. Theoretical analyses of resonance parameter measurement are presented. Theoretic error of the method is investigated and corrected. Experiments are conducted and the results indicate that blade resonance parameter identification is achieved without once-per revolution sensor.

A 10-kW series resonant converter design, transistor characterization, and base-drive optimization

NASA Technical Reports Server (NTRS)

Robson, R. R.; Hancock, D. J.

1982-01-01

The development, components, and performance of a transistor-based 10 kW series resonant converter for use in resonant circuits in space applications is described. The transistors serve to switch on the converter current, which has a half-sinusoid waveform when the transistor is in saturation. The goal of the program was to handle an input-output voltage range of 230-270 Vdc, an output voltage range of 200-500 Vdc, and a current limit range of 0-20 A. Testing procedures for the D60T and D7ST transistors are outlined and base drive waveforms are presented. The total device dissipation was minimized and found to be independent of the regenerative feedback ratio at lower current levels. Dissipation was set at within 10% and rise times were found to be acceptable. The finished unit displayed a 91% efficiency at full power levels of 500 V and 20 A and 93.7% at 500 V and 10 A.

Resonance treatment using pin-based pointwise energy slowing-down method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, Sooyoung, E-mail: csy0321@unist.ac.kr; Lee, Changho, E-mail: clee@anl.gov; Lee, Deokjung, E-mail: deokjung@unist.ac.kr

A new resonance self-shielding method using a pointwise energy solution has been developed to overcome the drawbacks of the equivalence theory. The equivalence theory uses a crude resonance scattering source approximation, and assumes a spatially constant scattering source distribution inside a fuel pellet. These two assumptions cause a significant error, in that they overestimate the multi-group effective cross sections, especially for {sup 238}U. The new resonance self-shielding method solves pointwise energy slowing-down equations with a sub-divided fuel rod. The method adopts a shadowing effect correction factor and fictitious moderator material to model a realistic pointwise energy solution. The slowing-down solutionmore » is used to generate the multi-group cross section. With various light water reactor problems, it was demonstrated that the new resonance self-shielding method significantly improved accuracy in the reactor parameter calculation with no compromise in computation time, compared to the equivalence theory.« less

Multi-resonant wideband energy harvester based on a folded asymmetric M-shaped cantilever

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Meng; Mao, Haiyang; Li, Zhigang

2015-07-15

This article reports a compact wideband piezoelectric vibration energy harvester consisting of three proof masses and an asymmetric M-shaped cantilever. The M-shaped beam comprises a main beam and two folded and dimension varied auxiliary beams interconnected through the proof mass at the end of the main cantilever. Such an arrangement constitutes a three degree-of-freedom vibrating body, which can tune the resonant frequencies of its first three orders close enough to obtain a utility wide bandwidth. The finite element simulation results and the experimental results are well matched. The operation bandwidth comprises three adjacent voltage peaks on account of the frequencymore » interval shortening mechanism. The result shows that the proposed piezoelectric energy harvester could be efficient and adaptive in practical vibration circumstance based on multiple resonant modes.« less

Tunable plasmon-induced transparency effect based on self-asymmetric H-shaped resonators meta-atoms

NASA Astrophysics Data System (ADS)

Cheng, Zhaoxiang; Chen, Lin; Zang, Xiaofei; Cai, Bin; Peng, Yan; Zhu, Yiming

2015-03-01

We have proposed and demonstrated a tunable plasmon-induced transparency (PIT) effect from two ways, based on self-asymmetric H-shaped resonators (AHR) meta-atoms. The tunable PIT effect is realized via varying polarization angles and coupling distances. First, by proper design, transition from PIT mode to dipole mode is theoretically and experimentally demonstrated by simply adjusting the polarization angle. Also, the manipulation of ‘dark-mode’ resonance intensity from strong to weak is achieved by varying coupling strength with different distances, which provided insight into the magnetic coupling hybridization mechanism. Prospectively, due to its special tunable characteristics, the AHR meta-atoms may be widely used in slow light, filters and switch devices.

Plasmonic Refractive Index Sensor with High Figure of Merit Based on Concentric-Rings Resonator

PubMed Central

Zhang, Zhaojian; Yang, Junbo; He, Xin; Zhang, Jingjing; Huang, Jie; Chen, Dingbo; Han, Yunxin

2018-01-01

A plasmonic refractive index (RI) sensor based on metal-insulator-metal (MIM) waveguide coupled with concentric double rings resonator (CDRR) is proposed and investigated numerically. Utilizing the novel supermodes of the CDRR, the FWHM of the resonant wavelength can be modulated, and a sensitivity of 1060 nm/RIU with high figure of merit (FOM) 203.8 is realized in the near-infrared region. The unordinary modes, as well as the influence of structure parameters on the sensing performance, are also discussed. Such plasmonic sensor with simple framework and high optical resolution could be applied to on-chip sensing systems and integrated optical circuits. Besides, the special cases of bio-sensing and triple rings are also discussed. PMID:29300331

A tunable single-monochromator Raman system based on the supercontinuum laser and tunable filters for resonant Raman profile measurements.

PubMed

Liu, X-L; Liu, H-N; Tan, P-H

2017-08-01

Resonant Raman spectroscopy requires that the wavelength of the laser used is close to that of an electronic transition. A tunable laser source and a triple spectrometer are usually necessary for resonant Raman profile measurements. However, such a system is complex with low signal throughput, which limits its wide application by scientific community. Here, a tunable micro-Raman spectroscopy system based on the supercontinuum laser, transmission grating, tunable filters, and single-stage spectrometer is introduced to measure the resonant Raman profile. The supercontinuum laser in combination with transmission grating makes a tunable excitation source with a bandwidth of sub-nanometer. Such a system exhibits continuous excitation tunability and high signal throughput. Its good performance and flexible tunability are verified by resonant Raman profile measurement of twisted bilayer graphene, which demonstrates its potential application prospect for resonant Raman spectroscopy.

Analysis of a highly birefringent asymmetric photonic crystal fibre based on a surface plasmon resonance sensor

NASA Astrophysics Data System (ADS)

Liu, Chao; Wang, Famei; Zheng, Shijie; Sun, Tao; Lv, Jingwei; Liu, Qiang; Yang, Lin; Mu, Haiwei; Chu, Paul K.

2016-07-01

A highly birefringent photonic crystal fibre is proposed and characterized based on a surface plasmon resonance sensor. The birefringence of the sensor is numerically analyzed by the finite-element method. In the numerical simulation, the resonance wavelength can be directly positioned at this birefringence abrupt change point and the depth of the abrupt change of birefringence reflects the intensity of excited surface plasmon. Consequently, the novel approach can accurately locate the resonance peak of the system without analyzing the loss spectrum. Simulated average sensitivity is as high as 1131 nm/RIU, corresponding to a resolution of 1 × 10-4 RIU in this sensor. Therefore, results obtained via the approach not only show polarization independence and less noble metal consumption, but also reveal better performance in terms of accuracy and computation efficiency.

Graphene-based absorber exploiting guided mode resonances in one-dimensional gratings.

PubMed

Grande, M; Vincenti, M A; Stomeo, T; Bianco, G V; de Ceglia, D; Aközbek, N; Petruzzelli, V; Bruno, G; De Vittorio, M; Scalora, M; D'Orazio, A

2014-12-15

A one-dimensional dielectric grating, based on a simple geometry, is proposed and investigated to enhance light absorption in a monolayer graphene exploiting guided mode resonances. Numerical findings reveal that the optimized configuration is able to absorb up to 60% of the impinging light at normal incidence for both TE and TM polarizations resulting in a theoretical enhancement factor of about 26 with respect to the monolayer graphene absorption (≈2.3%). Experimental results confirm this behavior showing CVD graphene absorbance peaks up to about 40% over narrow bands of a few nanometers. The simple and flexible design points to a way to realize innovative, scalable and easy-to-fabricate graphene-based optical absorbers.

Mie resonances to tailor random lasers

NASA Astrophysics Data System (ADS)

García, P. D.; Ibisate, M.; Sapienza, R.; Wiersma, D. S.; López, C.

2009-07-01

In this paper, we present an optical characterization of photonic glass-based random lasers. We show how the resonant behavior of diffuse light transport through such systems can tailor the lasing emission when a gain medium is added to the glass. A DNA-based organic dye is used as gain medium. The resonances in the transport mean-free path influence the lasing wavelength of the random laser. The laser wavelength is therefore controlled by the sphere diameter. Furthermore, the existence of Mie resonances reduces the necessary pump energy to reach the lasing threshold.

The N+CPT resonance

NASA Astrophysics Data System (ADS)

Crescimanno, Michael; Hohensee, Michael; Hancox, Cindy; Phillips, David; Walsworth, Ron

2007-06-01

Of relevance to compact atomic frequency standards, we investigate a model of the N+CPT joint optical resonance. We compare analytical solutions of a 4-state theory, as well as numerical solutions of the optical Bloch equations, to experimental investigations of N+CPT resonances in 87Rb. Our results inform the optimization of N+CPT based frequency standards.

Measurement of Antioxidant Capacity by Electron Spin Resonance Spectroscopy Based on Copper(II) Reduction.

PubMed

Li, Dan; Jiang, Jia; Han, Dandan; Yu, Xinyu; Wang, Kun; Zang, Shuang; Lu, Dayong; Yu, Aimin; Zhang, Ziwei

2016-04-05

A new method is proposed for measuring the antioxidant capacity by electron spin resonance spectroscopy based on the loss of electron spin resonance signal after Cu(2+) is reduced to Cu(+) with antioxidant. Cu(+) was removed by precipitation in the presence of SCN(-). The remaining Cu(2+) was coordinated with diethyldithiocarbamate, extracted into n-butanol and determined by electron spin resonance spectrometry. Eight standards widely used in antioxidant capacity determination, including Trolox, ascorbic acid, ferulic acid, rutin, caffeic acid, quercetin, chlorogenic acid, and gallic acid were investigated. The standard curves for determining the eight standards were plotted, and results showed that the linear regression correlation coefficients were all high enough (r > 0.99). Trolox equivalent antioxidant capacity values for the antioxidant standards were calculated, and a good correlation (r > 0.94) between the values obtained by the present method and cupric reducing antioxidant capacity method was observed. The present method was applied to the analysis of real fruit samples and the evaluation of the antioxidant capacity of these fruits.

[Detection of Weak Speech Signals from Strong Noise Background Based on Adaptive Stochastic Resonance].

PubMed

Lu, Huanhuan; Wang, Fuzhong; Zhang, Huichun

2016-04-01

Traditional speech detection methods regard the noise as a jamming signal to filter,but under the strong noise background,these methods lost part of the original speech signal while eliminating noise.Stochastic resonance can use noise energy to amplify the weak signal and suppress the noise.According to stochastic resonance theory,a new method based on adaptive stochastic resonance to extract weak speech signals is proposed.This method,combined with twice sampling,realizes the detection of weak speech signals from strong noise.The parameters of the systema,b are adjusted adaptively by evaluating the signal-to-noise ratio of the output signal,and then the weak speech signal is optimally detected.Experimental simulation analysis showed that under the background of strong noise,the output signal-to-noise ratio increased from the initial value-7dB to about 0.86 dB,with the gain of signalto-noise ratio is 7.86 dB.This method obviously raises the signal-to-noise ratio of the output speech signals,which gives a new idea to detect the weak speech signals in strong noise environment.

The design of photoelectric signal processing system for a nuclear magnetic resonance gyroscope based on FPGA

NASA Astrophysics Data System (ADS)

Zhang, Xian; Zhou, Binquan; Li, Hong; Zhao, Xinghua; Mu, Weiwei; Wu, Wenfeng

2017-10-01

Navigation technology is crucial to the national defense and military, which can realize the measurement of orientation, positioning, attitude and speed for moving object. Inertial navigation is not only autonomous, real-time, continuous, hidden, undisturbed but also no time-limited and environment-limited. The gyroscope is the core component of the inertial navigation system, whose precision and size are the bottleneck of the performance. However, nuclear magnetic resonance gyroscope is characteristic of the advantage of high precision and small size. Nuclear magnetic resonance gyroscope can meet the urgent needs of high-tech weapons and equipment development of new generation. This paper mainly designs a set of photoelectric signal processing system for nuclear magnetic resonance gyroscope based on FPGA, which process and control the information of detecting laser .The photoelectric signal with high frequency carrier is demodulated by in-phase and quadrature demodulation method. Finally, the processing system of photoelectric signal can compensate the residual magnetism of the shielding barrel and provide the information of nuclear magnetic resonance gyroscope angular velocity.

A surface plasmon resonance based biochip for the detection of patulin toxin

NASA Astrophysics Data System (ADS)

Pennacchio, Anna; Ruggiero, Giuseppe; Staiano, Maria; Piccialli, Gennaro; Oliviero, Giorgia; Lewkowicz, Aneta; Synak, Anna; Bojarski, Piotr; D'Auria, Sabato

2014-08-01

Patulin is a toxic secondary metabolite of a number of fungal species belonging to the genera Penicillium and Aspergillus. One important aspect of the patulin toxicity in vivo is an injury of the gastrointestinal tract including ulceration and inflammation of the stomach and intestine. Recently, patulin has been shown to be genotoxic by causing oxidative damage to the DNA, and oxidative DNA base modifications have been considered to play a role in mutagenesis and cancer initiation. Conventional analytical methods for patulin detection involve chromatographic analyses, such as HPLC, GC, and, more recently, techniques such as LC/MS and GC/MS. All of these methods require the use of extensive protocols and the use of expensive analytical instrumentation. In this work, the conjugation of a new derivative of patulin to the bovine serum albumin for the production of polyclonal antibodies is described, and an innovative competitive immune-assay for detection of patulin is presented. Experimentally, an important part of the detection method is based on the optical technique called surface plasmon resonance (SPR). Laser beam induced interactions between probe and target molecules in the vicinity of gold surface of the biochip lead to the shift in resonance conditions and consequently to slight but easily detectable change of reflectivity.

Symmetric Resonance Charge Exchange Cross Section Based on Impact Parameter Treatment

NASA Technical Reports Server (NTRS)

Omidvar, Kazem; Murphy, Kendrah; Atlas, Robert (Technical Monitor)

2002-01-01

Using a two-state impact parameter approximation, a calculation has been carried out to obtain symmetric resonance charge transfer cross sections between nine ions and their parent atoms or molecules. Calculation is based on a two-dimensional numerical integration. The method is mostly suited for hydrogenic and some closed shell atoms. Good agreement has been obtained with the results of laboratory measurements for the ion-atom pairs H+-H, He+-He, and Ar+-Ar. Several approximations in a similar published calculation have been eliminated.

Properties of resonant trans-Neptunian objects based on Herschel Space Observatory data

NASA Astrophysics Data System (ADS)

Farkas Anikó, Takácsné; Kiss, Csaba; Mueller, Thomas G.; Mommert, Michael; Vilenius, Esa

2016-10-01

The goal of our work is to characterise the physical characteristics of resonant, detached and scattered disk objects in the trans-Neptunian region, observed in the framework of the "TNOs are Cool!" Herschel Open Time Key Program. Based on thermal emission measurements with the Herschel/PACS and Spitzer/MIPS instruments we were able to determine size, albedo, and surface thermal properties for 23 objects using radiometric modelling techniques. This is the first analysis in which the physical properties of objects in the outer resonances are determined for a larger sample. In addition to the results for individual objects, we have compared these characteristic with the bulk properties of other populations of the trans-Neptunian region. The newly analysed objects show e.g. a large variety of beaming factors, indicating diverse surfaces, and in general they follow the albedo-colour clustering identified earlier for Kuiper belt objects and Centaurs, further strengthening the evidence for a compositional discontinuity in the young solar system.

Disc resonator gyroscope fabrication process requiring no bonding alignment

NASA Technical Reports Server (NTRS)

Shcheglov, Kirill V. (Inventor)

2010-01-01

A method of fabricating a resonant vibratory sensor, such as a disc resonator gyro. A silicon baseplate wafer for a disc resonator gyro is provided with one or more locating marks. The disc resonator gyro is fabricated by bonding a blank resonator wafer, such as an SOI wafer, to the fabricated baseplate, and fabricating the resonator structure according to a pattern based at least in part upon the location of the at least one locating mark of the fabricated baseplate. MEMS-based processing is used for the fabrication processing. In some embodiments, the locating mark is visualized using optical and/or infrared viewing methods. A disc resonator gyroscope manufactured according to these methods is described.

Development of a high-sensitivity and portable cell using Helmholtz resonance for noninvasive blood glucose-level measurement based on photoacoustic spectroscopy.

PubMed

Tachibana, K; Okada, K; Kobayashi, R; Ishihara, Y

2016-08-01

We describe the possibility of high-sensitivity noninvasive blood glucose measurement based on photoacoustic spectroscopy (PAS). The demand for noninvasive blood glucose-level measurement has increased due to the explosive increase in diabetic patients. We have developed a noninvasive blood glucose-level measurement based on PAS. The conventional method uses a straight-type resonant cell. However, the cell volume is large, which results in a low detection sensitivity and difficult portability. In this paper, a small-sized Helmholtz-type resonant cell is proposed to improve detection sensitivity and portability by reducing the cell dead volume. First, the acoustic property of the small-sized Helmholtz-type resonant cell was evaluated by performing an experiment using a silicone rubber. As a result, the detection sensitivity of the small-sized Helmholtz-type resonant cell was approximately two times larger than that of the conventional straight-type resonant cell. In addition, the inside volume was approximately 30 times smaller. Second, the detection limits of glucose concentration were estimated by performing an experiment using glucose solutions. The experimental results showed that a glucose concentration of approximately 1% was detected by the small-sized Helmholtz-type resonant cell. Although these results on the sensitivity of blood glucose-level measurement are currently insufficient, they suggest that miniaturization of a resonance cell is effective in the application of noninvasive blood glucose-level measurement.

Low-Lying π* Resonances of Standard and Rare DNA and RNA Bases Studied by the Projected CAP/SAC-CI Method.

PubMed

Kanazawa, Yuki; Ehara, Masahiro; Sommerfeld, Thomas

2016-03-10

Low-lying π* resonance states of DNA and RNA bases have been investigated by the recently developed projected complex absorbing potential (CAP)/symmetry-adapted cluster-configuration interaction (SAC-CI) method using a smooth Voronoi potential as CAP. In spite of the challenging CAP applications to higher resonance states of molecules of this size, the present calculations reproduce resonance positions observed by electron transmission spectra (ETS) provided the anticipated deviations due to vibronic effects and limited basis sets are taken into account. Moreover, for the standard nucleobases, the calculated positions and widths qualitatively agree with those obtained in previous electron scattering calculations. For guanine, both keto and enol forms were examined, and the calculated values of the keto form agree clearly better with the experimental findings. In addition to these standard bases, three modified forms of cytosine, which serve as epigenetic or biomarkers, were investigated: formylcytosine, methylcytosine, and chlorocytosine. Last, a strong correlation between the computed positions and the observed ETS values is demonstrated, clearly suggesting that the present computational protocol should be useful for predicting the π* resonances of congeners of DNA and RNA bases.

The System of Secondary Periodicities and Resonances Based on β Lyrae Magnetic Field

NASA Astrophysics Data System (ADS)

Skulsky, M. Yu.

Original integral interconsistent and interconnected magnetohydrodynamical system of periodicities and resonances over their long-time variabilities is developed. The study is based upon three different observed secondary periods in β Lyrae system and taking into account geometrical features of the nonstandard magnetic field in a losing star, as well as due to the asynchronizm of the orbital and rotational periods.

Delta connected resonant snubber circuit

DOEpatents

Lai, J.S.; Peng, F.Z.; Young, R.W. Sr.; Ott, G.W. Jr.

1998-01-20

A delta connected, resonant snubber-based, soft switching, inverter circuit achieves lossless switching during dc-to-ac power conversion and power conditioning with minimum component count and size. Current is supplied to the resonant snubber branches solely by the dc supply voltage through the main inverter switches and the auxiliary switches. Component count and size are reduced by use of a single semiconductor switch in the resonant snubber branches. Component count is also reduced by maximizing the use of stray capacitances of the main switches as parallel resonant capacitors. Resonance charging and discharging of the parallel capacitances allows lossless, zero voltage switching. In one embodiment, circuit component size and count are minimized while achieving lossless, zero voltage switching within a three-phase inverter. 36 figs.

Delta connected resonant snubber circuit

DOEpatents

Lai, Jih-Sheng; Peng, Fang Zheng; Young, Sr., Robert W.; Ott, Jr., George W.

1998-01-01

A delta connected, resonant snubber-based, soft switching, inverter circuit achieves lossless switching during dc-to-ac power conversion and power conditioning with minimum component count and size. Current is supplied to the resonant snubber branches solely by the dc supply voltage through the main inverter switches and the auxiliary switches. Component count and size are reduced by use of a single semiconductor switch in the resonant snubber branches. Component count is also reduced by maximizing the use of stray capacitances of the main switches as parallel resonant capacitors. Resonance charging and discharging of the parallel capacitances allows lossless, zero voltage switching. In one embodiment, circuit component size and count are minimized while achieving lossless, zero voltage switching within a three-phase inverter.

A new quadrature annular resonator for 3 T MRI based on artificial-dielectrics

NASA Astrophysics Data System (ADS)

Mikhailovskaya, Anna A.; Shchelokova, Alena V.; Dobrykh, Dmitry A.; Sushkov, Ivan V.; Slobozhanyuk, Alexey P.; Webb, Andrew

2018-06-01

Dielectric resonators have previously been constructed for ultra-high frequency magnetic resonance imaging and microscopy. However, it is challenging to design these dielectric resonators at clinical field strengths due to their intrinsically large dimensions, especially when using materials with moderate permittivity. Here we propose and characterize a novel approach using artificial-dielectrics which reduces substantially the required outer diameter of the resonator. For a resonator designed to operate in a 3 Tesla scanner using water as the dielectric, a reduction in outer diameter of 37% was achieved. When used in an inductively-coupled wireless mode, the sensitivity of the artificial-dielectric resonator was measured to be slightly higher than that of a standard dielectric resonator operating in its degenerate circularly-polarized hybrid electromagnetic modes (HEM11). This study demonstrates the first application of an artificial-dielectric approach to MR volume coil design.

Tunable band-stop plasmonic filter based on square ring resonators in a metal-insulator-metal structure

NASA Astrophysics Data System (ADS)

Zavvari, Mahdi; Taleb Hesami Azar, Milad; Arashmehr, Armin

2017-11-01

A novel high-performance plasmonic filter based on a metal-insulator-metal structure is analysed for band-rejection applications. A square ring is used in proximity to the waveguide in order to resonate with some transmitted wavelengths and drop them to prevent from propagation towards the output. The effect of the structural parameters of square ring resonator is studied deploying the finite difference time domain method and the possibility of tuning the rejected wavelength is investigated in detail. The simulation results demonstrate that the rejected wavelength has a red-shift with increase in the size of the ring's dimensions. A further study is carried out considering narrowing the bandwidth. To improve the quality factor of the proposed filter, a small ring within the resonator is introduced that considerably decreases the bandwidth of the peak with respect to its central wavelength.

Utilizing hyaluronic acid as a versatile platform for fluorescence resonance energy transfer-based glucose sensing.

PubMed

Ge, Minghao; Bai, Pengli; Chen, Mingli; Tian, Jingjing; Hu, Jun; Zhi, Xu; Yin, Huancai; Yin, Jian

2018-03-01

Here, we utilized the ultrasonic emulsification technique to generate hyaluronic acid microspheres incorporating a fluorescence-based glucose biosensor. We synthesized a novel lanthanide ion luminophore based on Eu 3+ . Eu sulfosuccinimidyl dextran (Eu-dextran) and Alexa Fluor 647 sulfosuccinimidyl-ConA (Alexa Fluor 647-ConA) were encapsulated in hyaluronic acid hydrogel to generate microspheres. Glucose sensing was carried out using a fluorescence resonance energy transfer (FRET)-based assay principle. A proportional fluorescence intensity increase was found within a 0.5-10-mM glucose concentration range. The glucose-sensing strategy showed an excellent tolerance for potential interferents. Meanwhile, the fluorescent signal of hyaluronic acid microspheres was very stable after testing for 72 h in glucose solution. Overall, hyaluronic acid microspheres encapsulating sensing biomolecules offer a stable and biocompatible biosensor for a variety of applications including cell culture systems, tissue engineering, detection of blood glucose, etc. Graphical abstract We report an ingenious biosensor encapsulated in hyaluronic acid microspheres for monitoring of glucose. Glucose sensing is carried out using a fluorescence resonance energy transfer-based assay principle with a novel lanthanide ions luminophore. The glucose detection system has excellent biocompatibility and stability for monitoring of glucose.

Self-transducing silicon nanowire electromechanical systems at room temperature.

PubMed

He, Rongrui; Feng, X L; Roukes, M L; Yang, Peidong

2008-06-01

Electronic readout of the motions of genuinely nanoscale mechanical devices at room temperature imposes an important challenge for the integration and application of nanoelectromechanical systems (NEMS). Here, we report the first experiments on piezoresistively transduced very high frequency Si nanowire (SiNW) resonators with on-chip electronic actuation at room temperature. We have demonstrated that, for very thin (~90 nm down to ~30 nm) SiNWs, their time-varying strain can be exploited for self-transducing the devices' resonant motions at frequencies as high as approximately 100 MHz. The strain of wire elongation, which is only second-order in doubly clamped structures, enables efficient displacement transducer because of the enhanced piezoresistance effect in these SiNWs. This intrinsically integrated transducer is uniquely suited for a class of very thin wires and beams where metallization and multilayer complex patterning on devices become impractical. The 30 nm thin SiNW NEMS offer exceptional mass sensitivities in the subzeptogram range. This demonstration makes it promising to advance toward NEMS sensors based on ultrathin and even molecular-scale SiNWs, and their monolithic integration with microelectronics on the same chip.

Theoretical analysis of microring resonator-based biosensor with high resolution and free of temperature influence

NASA Astrophysics Data System (ADS)

Jian, Aoqun; Zou, Lu; Tang, Haiquan; Duan, Qianqian; Ji, Jianlong; Zhang, Qianwu; Zhang, Xuming; Sang, Shengbo

2017-06-01

The issue of thermal effects is inevitable for the ultrahigh refractive index (RI) measurement. A biosensor with parallel-coupled dual-microring resonator configuration is proposed to achieve high resolution and free thermal effects measurement. Based on the coupled-resonator-induced transparency effect, the design and principle of the biosensor are introduced in detail, and the performance of the sensor is deduced by simulations. Compared to the biosensor based on a single-ring configuration, the designed biosensor has a 10-fold increased Q value according to the simulation results, thus the sensor is expected to achieve a particularly high resolution. In addition, the output signal of the mathematical model of the proposed sensor can eliminate the thermal influence by adopting an algorithm. This work is expected to have great application potentials in the areas of high-resolution RI measurement, such as biomedical discoveries, virus screening, and drinking water safety.

Review of optoelectronic oscillators based on modelocked lasers and resonant tunneling diode optoelectronics

NASA Astrophysics Data System (ADS)

Ironside, C. N.; Haji, Mohsin; Hou, Lianping; Akbar, Jehan; Kelly, Anthony E.; Seunarine, K.; Romeira, Bruno; Figueiredo, José M. L.

2011-05-01

Optoelectronic oscillators can provide low noise oscillators at radio frequencies in the 0.5-40 GHz range and in this paper we review two recently introduced approaches to optoelectronic oscillators. Both approaches use an optical fibre feedback loop. One approach is based on passively modelocked laser diodes and in a 40 GHz oscillator achieves up to 30 dB noise reduction. The other approach is based on resonant tunneling diode optoelectronic devices and in a 1.4 GHz oscillator can achieve up to 30 dB noise reduction.

Ultra-wideband tunable resonator based on varactor-loaded complementary split-ring resonators on a substrate-integrated waveguide for microwave sensor applications.

PubMed

Sam, Somarith; Lim, Sungjoon

2013-04-01

This paper presents the modeling, design, fabrication, and measurement of an ultra-wideband tunable twoport resonator in which the substrate-integrated waveguide, complementary split-ring resonators (CSRRs), and varactors are embedded on the same planar platform. The tuning of the passband frequency is generated by a simple single dc voltage of 0 to 36 V, which is applied to each varactor on the CSRRs. Different capacitance values and resonant frequencies are produced while a nearly constant absolute bandwidth is maintained. The resonant frequency is varied between 0.83 and 1.58 GHz and has a wide tuning ratio of 90%.

Fiber Optic Surface Plasmon Resonance-Based Biosensor Technique: Fabrication, Advancement, and Application.

PubMed

Liang, Gaoling; Luo, Zewei; Liu, Kunping; Wang, Yimin; Dai, Jianxiong; Duan, Yixiang

2016-05-03

Fiber optic-based biosensors with surface plasmon resonance (SPR) technology are advanced label-free optical biosensing methods. They have brought tremendous progress in the sensing of various chemical and biological species. This review summarizes four sensing configurations (prism, grating, waveguide, and fiber optic) with two ways, attenuated total reflection (ATR) and diffraction, to excite the surface plasmons. Meanwhile, the designs of different probes (U-bent, tapered, and other probes) are also described. Finally, four major types of biosensors, immunosensor, DNA biosensor, enzyme biosensor, and living cell biosensor, are discussed in detail for their sensing principles and applications. Future prospects of fiber optic-based SPR sensor technology are discussed.

Tiny surface plasmon resonance sensor integrated on silicon waveguide based on vertical coupling into finite metal-insulator-metal plasmonic waveguide.

PubMed

Lee, Dong-Jin; Yim, Hae-Dong; Lee, Seung-Gol; O, Beom-Hoan

2011-10-10

We propose a tiny surface plasmon resonance (SPR) sensor integrated on a silicon waveguide based on vertical coupling into a finite thickness metal-insulator-metal (f-MIM) plasmonic waveguide structure acting as a Fabry-Perot resonator. The resonant characteristics of vertically coupled f-MIM plasmonic waveguides are theoretically investigated and optimized. Numerical results show that the SPR sensor with a footprint of ~0.0375 μm2 and a sensitivity of ~635 nm/RIU can be designed at a 1.55 μm transmission wavelength.

Isotopic imaging via nuclear resonance fluorescence with laser-based Thomson radiation

DOEpatents

Barty, Christopher P. J. [Hayward, CA; Hartemann, Frederic V [San Ramon, CA; McNabb, Dennis P [Alameda, CA; Pruet, Jason A [Brentwood, CA

2009-07-21

The present invention utilizes novel laser-based, high-brightness, high-spatial-resolution, pencil-beam sources of spectrally pure hard x-ray and gamma-ray radiation to induce resonant scattering in specific nuclei, i.e., nuclear resonance fluorescence. By monitoring such fluorescence as a function of beam position, it is possible to image in either two dimensions or three dimensions, the position and concentration of individual isotopes in a specific material configuration. Such methods of the present invention material identification, spatial resolution of material location and ability to locate and identify materials shielded by other materials, such as, for example, behind a lead wall. The foundation of the present invention is the generation of quasimonochromatic high-energy x-ray (100's of keV) and gamma-ray (greater than about 1 MeV) radiation via the collision of intense laser pulses from relativistic electrons. Such a process as utilized herein, i.e., Thomson scattering or inverse-Compton scattering, produces beams having diameters from about 1 micron to about 100 microns of high-energy photons with a bandwidth of .DELTA.E/E of approximately 10E.sup.-3.

Temperature dependence of spin-torque driven ferromagnetic resonance in MgO-based magnetic tunnel junction with a perpendicularly free layer

NASA Astrophysics Data System (ADS)

Wang, Xiao; Feng, Jiafeng; Guo, Peng; Wei, H. X.; Han, X. F.; Fang, B.; Zeng, Z. M.

2017-12-01

We report the temperature dependence of the spin-torque (ST) driven ferromagnetic resonance in MgO-based magnetic tunnel junction (MTJ) nanopillars with a perpendicularly free layer and an in-plane reference layer. From the evolution of the resonance frequency with magnetic field, we clearly identify the free-layer resonance mode and reference-layer mode. For the reference layer, we demonstrate a monotonic increase in resonance frequency and the effective damping with decreasing temperature, which suggests the saturated magnetization of the reference layer is dominant. However, for the free layer, the frequency and damping exhibit almost no change with temperature, indicating that the perpendicular magnetic anisotropy plays an important role in magnetization dynamics of the free layer.

A portable blood plasma clot micro-elastometry device based on resonant acoustic spectroscopy

NASA Astrophysics Data System (ADS)

Krebs, C. R.; Li, Ling; Wolberg, Alisa S.; Oldenburg, Amy L.

2015-07-01

Abnormal blood clot stiffness is an important indicator of coagulation disorders arising from a variety of cardiovascular diseases and drug treatments. Here, we present a portable instrument for elastometry of microliter volume blood samples based upon the principle of resonant acoustic spectroscopy, where a sample of well-defined dimensions exhibits a fundamental longitudinal resonance mode proportional to the square root of the Young's modulus. In contrast to commercial thromboelastography, the resonant acoustic method offers improved repeatability and accuracy due to the high signal-to-noise ratio of the resonant vibration. We review the measurement principles and the design of a magnetically actuated microbead force transducer applying between 23 pN and 6.7 nN, providing a wide dynamic range of elastic moduli (3 Pa-27 kPa) appropriate for measurement of clot elastic modulus (CEM). An automated and portable device, the CEMport, is introduced and implemented using a 2 nm resolution displacement sensor with demonstrated accuracy and precision of 3% and 2%, respectively, of CEM in biogels. Importantly, the small strains (<0.13%) and low strain rates (<1/s) employed by the CEMport maintain a linear stress-to-strain relationship which provides a perturbative measurement of the Young's modulus. Measurements of blood plasma CEM versus heparin concentration show that CEMport is sensitive to heparin levels below 0.050 U/ml, which suggests future applications in sensing heparin levels of post-surgical cardiopulmonary bypass patients. The portability, high accuracy, and high precision of this device enable new clinical and animal studies for associating CEM with blood coagulation disorders, potentially leading to improved diagnostics and therapeutic monitoring.

A portable blood plasma clot micro-elastometry device based on resonant acoustic spectroscopy

PubMed Central

Krebs, C. R.; Li, Ling; Wolberg, Alisa S.; Oldenburg, Amy L.

2015-01-01

Abnormal blood clot stiffness is an important indicator of coagulation disorders arising from a variety of cardiovascular diseases and drug treatments. Here, we present a portable instrument for elastometry of microliter volume blood samples based upon the principle of resonant acoustic spectroscopy, where a sample of well-defined dimensions exhibits a fundamental longitudinal resonance mode proportional to the square root of the Young’s modulus. In contrast to commercial thromboelastography, the resonant acoustic method offers improved repeatability and accuracy due to the high signal-to-noise ratio of the resonant vibration. We review the measurement principles and the design of a magnetically actuated microbead force transducer applying between 23 pN and 6.7 nN, providing a wide dynamic range of elastic moduli (3 Pa–27 kPa) appropriate for measurement of clot elastic modulus (CEM). An automated and portable device, the CEMport, is introduced and implemented using a 2 nm resolution displacement sensor with demonstrated accuracy and precision of 3% and 2%, respectively, of CEM in biogels. Importantly, the small strains (<0.13%) and low strain rates (<1/s) employed by the CEMport maintain a linear stress-to-strain relationship which provides a perturbative measurement of the Young’s modulus. Measurements of blood plasma CEM versus heparin concentration show that CEMport is sensitive to heparin levels below 0.050 U/ml, which suggests future applications in sensing heparin levels of post-surgical cardiopulmonary bypass patients. The portability, high accuracy, and high precision of this device enable new clinical and animal studies for associating CEM with blood coagulation disorders, potentially leading to improved diagnostics and therapeutic monitoring. PMID:26233406

A portable blood plasma clot micro-elastometry device based on resonant acoustic spectroscopy.

PubMed

Krebs, C R; Li, Ling; Wolberg, Alisa S; Oldenburg, Amy L

2015-07-01

Abnormal blood clot stiffness is an important indicator of coagulation disorders arising from a variety of cardiovascular diseases and drug treatments. Here, we present a portable instrument for elastometry of microliter volume blood samples based upon the principle of resonant acoustic spectroscopy, where a sample of well-defined dimensions exhibits a fundamental longitudinal resonance mode proportional to the square root of the Young's modulus. In contrast to commercial thromboelastography, the resonant acoustic method offers improved repeatability and accuracy due to the high signal-to-noise ratio of the resonant vibration. We review the measurement principles and the design of a magnetically actuated microbead force transducer applying between 23 pN and 6.7 nN, providing a wide dynamic range of elastic moduli (3 Pa-27 kPa) appropriate for measurement of clot elastic modulus (CEM). An automated and portable device, the CEMport, is introduced and implemented using a 2 nm resolution displacement sensor with demonstrated accuracy and precision of 3% and 2%, respectively, of CEM in biogels. Importantly, the small strains (<0.13%) and low strain rates (<1/s) employed by the CEMport maintain a linear stress-to-strain relationship which provides a perturbative measurement of the Young's modulus. Measurements of blood plasma CEM versus heparin concentration show that CEMport is sensitive to heparin levels below 0.050 U/ml, which suggests future applications in sensing heparin levels of post-surgical cardiopulmonary bypass patients. The portability, high accuracy, and high precision of this device enable new clinical and animal studies for associating CEM with blood coagulation disorders, potentially leading to improved diagnostics and therapeutic monitoring.

A loop-gap resonator for chirality-sensitive nuclear magneto-electric resonance (NMER)

NASA Astrophysics Data System (ADS)

Garbacz, Piotr; Fischer, Peer; Krämer, Steffen

2016-09-01

Direct detection of molecular chirality is practically impossible by methods of standard nuclear magnetic resonance (NMR) that is based on interactions involving magnetic-dipole and magnetic-field operators. However, theoretical studies provide a possible direct probe of chirality by exploiting an enantiomer selective additional coupling involving magnetic-dipole, magnetic-field, and electric field operators. This offers a way for direct experimental detection of chirality by nuclear magneto-electric resonance (NMER). This method uses both resonant magnetic and electric radiofrequency (RF) fields. The weakness of the chiral interaction though requires a large electric RF field and a small transverse RF magnetic field over the sample volume, which is a non-trivial constraint. In this study, we present a detailed study of the NMER concept and a possible experimental realization based on a loop-gap resonator. For this original device, the basic principle and numerical studies as well as fabrication and measurements of the frequency dependence of the scattering parameter are reported. By simulating the NMER spin dynamics for our device and taking the 19F NMER signal of enantiomer-pure 1,1,1-trifluoropropan-2-ol, we predict a chirality induced NMER signal that accounts for 1%-5% of the standard achiral NMR signal.

BPF Theory-Based Design Method for Wireless Power Transfer System by Use of Magnetically Coupled Resonators

NASA Astrophysics Data System (ADS)

Awai, Ikuo

A wireless power transfer system based on two coupled resonators is analyzed by the filter design theory. Many useful relations between the equivalent circuit components are derived to comply with the change of power transfer condition along with the basic design of the system. Some design examples are given to deepen understanding of the theory and thus to stimulate using it for the system design. The effect of the resonator losses is also addressed to show the robustness of the theory, indicating the circuit loss of almost 10 dB does not deteriorate the matching condition too much.

[INVITED] Recent advances in surface plasmon resonance based fiber optic chemical and biosensors utilizing bulk and nanostructures

NASA Astrophysics Data System (ADS)

Gupta, Banshi D.; Kant, Ravi

2018-05-01

Surface plasmon resonance has established itself as an immensely acclaimed and influential optical sensing tool with quintessential applications in life sciences, environmental monitoring, clinical diagnostics, pharmaceutical developments and ensuring food safety. The implementation of sensing principle of surface plasmon resonance employing an optical fiber as a substrate has concomitantly resulted in the evolution of fiber optic surface plasmon resonance as an exceptionally lucrative scaffold for chemical and biosensing applications. This perspective article outlines the contemporary studies on fiber optic sensors founded on the sensing architecture of propagating as well as localized surface plasmon resonance. An in-depth review of the prevalent analytical and surface chemical tactics involved in configuring the sensing layer over an optical fiber for the detection of various chemical and biological entities is presented. The involvement of nanomaterials as a strategic approach to enhance the sensor sensitivity is furnished concurrently providing an insight into the diverse geometrical blueprints for designing fiber optic sensing probes. Representative examples from the literature are discussed to appreciate the latest advancements in this potentially valuable research avenue. The article concludes by identifying some of the key challenges and exploring the opportunities for expanding the scope and impact of surface plasmon resonance based fiber optic sensors.

Numerical studies on a plasmonic temperature nanosensor based on a metal-insulator-metal ring resonator structure for optical integrated circuit applications

NASA Astrophysics Data System (ADS)

Al-mahmod, Md. Jubayer; Hyder, Rakib; Islam, Md Zahurul

2017-07-01

A nanosensor, based on a metal-insulator-metal (MIM) plasmonic ring resonator, is proposed for potential on-chip temperature sensing and its performance is evaluated numerically. The sensor components can be fabricated by using planar processes on a silicon substrate, making its manufacturing compatible to planar electronic fabrication technology. The sensor, constructed using silver as the metal rings and a thermo-optic liquid ethanol film between the metal layers, is capable of sensing temperature with outstanding optical sensitivity, as high as -0.53 nm/°C. The resonance wavelength is found to be highly sensitive to the refractive index of the liquid dielectric film. The resonance peak can be tuned according to the requirement of intended application by changing the radii of the ring resonator geometries in the design phase. The compact size, planar and silicon-based design, and very high resolutions- these characteristics are expected to make this sensor technology a preferred choice for lab-on-a-chip applications, as compared to other contemporary sensors.

Role of targeted magnetic resonance imaging sequences in the surgical management of anterior skull base pathology.

PubMed

Chawla, S; Bowman, J; Gandhi, M; Panizza, B

2017-01-01

The skull base is a highly complex anatomical region that provides passage for important nerves and vessels as they course into and out of the cranial cavity. Key to the management of pathology in this region is a thorough understanding of the anatomy, with its variations, and the relationship of various neurovascular structures to the pathology in question. Targeted high-resolution magnetic resonance imaging on high field strength magnets can enable the skull base surgeon to understand this intricate relationship and deal with the pathology from a position of relative advantage. With the help of case studies, this paper illustrates the application of specialised magnetic resonance techniques to study pathology of the orbital apex in particular. The fine anatomical detail provided gives surgeons the ability to design an endonasal endoscopic procedure appropriate to the anatomy of the pathology.

Resonant tunneling structures based on epitaxial graphene on SiC

NASA Astrophysics Data System (ADS)

Nguyen, V. Hung; Bournel, A.; Dollfus, P.

2011-12-01

Recently some experiments have suggested that graphene epitaxially grown on SiC can exhibit an energy bandgap of 260 meV, which enhances the potential of this material for electronic applications. On this basis, we propose to use spatial doping to generate graphene-on-SiC double-barrier structures. The non-equilibrium Green's function technique for solving the massive Dirac model is applied to highlight typical transport phenomena such as the electron confinement and the resonant tunneling effects. The I-V characteristics of graphene resonant tunneling diodes were then investigated and the effect of different device parameters was discussed. It is finally shown that this kind of double-barrier junction provides an efficient way to confine the charge carriers in graphene and to design graphene resonant tunneling structures.

Resonant halide perovskite nanoparticles

NASA Astrophysics Data System (ADS)

Tiguntseva, Ekaterina Y.; Ishteev, Arthur R.; Komissarenko, Filipp E.; Zuev, Dmitry A.; Ushakova, Elena V.; Milichko, Valentin A.; Nesterov-Mueller, Alexander; Makarov, Sergey V.; Zakhidov, Anvar A.

2017-09-01

The hybrid halide perovskites is a prospective material for fabrication of cost-effective optical devices. Unique perovskites properties are used for solar cells and different photonic applications. Recently, perovskite-based nanophotonics has emerged. Here, we consider perovskite like a high-refractive index dielectric material, which can be considered to be a basis for nanoparticles fabrication with Mie resonances. As a result, we fabricate and study resonant perovskite nanoparticles with different sizes. We reveal, that spherical nanoparticles show enhanced photoluminescence signal. The achieved results lay a cornerstone in the field of novel types of organic-inorganic nanophotonics devices with optical properties improved by Mie resonances.

Mechanically detected terahertz electron spin resonance using SOI-based thin piezoresistive microcantilevers

NASA Astrophysics Data System (ADS)

Ohmichi, Eiji; Miki, Toshihiro; Horie, Hidekazu; Okamoto, Tsubasa; Takahashi, Hideyuki; Higashi, Yoshinori; Itoh, Shoichi; Ohta, Hitoshi

2018-02-01

We developed piezoresistive microcantilevers for mechanically detected electron spin resonance (ESR) in the millimeter-wave region. In this article, fabrication process and device characterization of our self-sensing microcantilevers are presented. High-frequency ESR measurements of a microcrystal of paramagnetic sample is also demonstrated at multiple frequencies up to 160 GHz at liquid helium temperature. Our fabrication is based on relatively simplified processes with silicon-on-insulator (SOI) wafers and spin-on diffusion doping, thus enabling cost-effective and time-saving cantilever fabrication.

Algorithm of resonance orders for the objects

NASA Astrophysics Data System (ADS)

Zhang, YongGang; Zhang, JianXue

2018-03-01

In mechanical engineering, the object resonance phenomena often occur when the external incident wave frequency is close to object of the natural frequency. Object resonance phenomena get the maximum value when the external incident frequency is equal to object the natural frequency. Experiments found that resonance intension of the object is changed, different objects resonance phenomena present different characteristics of ladders. Based on object orders resonance characteristics, the calculation method of object orders resonance is put forward in the paper, and the application for the light and sound waves on the seven order resonance characteristics by people feel, the result error is less than 1%.Visible in this paper, the method has high accuracy and usability. The calculation method reveals that some object resonance occur present order characteristic only four types, namely the first-orders resonance characteristics, third-orders characteristics, five orders characteristic, and seven orders characteristic.

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

PubMed Central

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

2016-01-01

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

Molecular beam epitaxy growth method for vertical-cavity surface-emitting laser resonators based on substrate thermal emission

NASA Astrophysics Data System (ADS)

Talghader, J. J.; Hadley, M. A.; Smith, J. S.

1995-12-01

A molecular beam epitaxy growth monitoring method is developed for distributed Bragg reflectors and vertical-cavity surface-emitting laser (VCSEL) resonators. The wavelength of the substrate thermal emission that corresponds to the optical cavity resonant wavelength is selected by a monochromator and monitored during growth. This method allows VCSEL cavities of arbitrary design wavelength to be grown with a single control program. This letter also presents a theoretical model for the technique which is based on transmission matrices and simple thermal emission properties. Demonstrated reproducibility of the method is well within 0.1%.

Surface Plasmon Resonance Biosensor Based on Smart Phone Platforms

NASA Astrophysics Data System (ADS)

Liu, Yun; Liu, Qiang; Chen, Shimeng; Cheng, Fang; Wang, Hanqi; Peng, Wei

2015-08-01

We demonstrate a fiber optic surface plasmon resonance (SPR) biosensor based on smart phone platforms. The light-weight optical components and sensing element are connected by optical fibers on a phone case. This SPR adaptor can be conveniently installed or removed from smart phones. The measurement, control and reference channels are illuminated by the light entering the lead-in fibers from the phone’s LED flash, while the light from the end faces of the lead-out fibers is detected by the phone’s camera. The SPR-sensing element is fabricated by a light-guiding silica capillary that is stripped off its cladding and coated with 50-nm gold film. Utilizing a smart application to extract the light intensity information from the camera images, the light intensities of each channel are recorded every 0.5 s with refractive index (RI) changes. The performance of the smart phone-based SPR platform for accurate and repeatable measurements was evaluated by detecting different concentrations of antibody binding to a functionalized sensing element, and the experiment results were validated through contrast experiments with a commercial SPR instrument. This cost-effective and portable SPR biosensor based on smart phones has many applications, such as medicine, health and environmental monitoring.

Surface Plasmon Resonance Biosensor Based on Smart Phone Platforms.

PubMed

Liu, Yun; Liu, Qiang; Chen, Shimeng; Cheng, Fang; Wang, Hanqi; Peng, Wei

2015-08-10

We demonstrate a fiber optic surface plasmon resonance (SPR) biosensor based on smart phone platforms. The light-weight optical components and sensing element are connected by optical fibers on a phone case. This SPR adaptor can be conveniently installed or removed from smart phones. The measurement, control and reference channels are illuminated by the light entering the lead-in fibers from the phone's LED flash, while the light from the end faces of the lead-out fibers is detected by the phone's camera. The SPR-sensing element is fabricated by a light-guiding silica capillary that is stripped off its cladding and coated with 50-nm gold film. Utilizing a smart application to extract the light intensity information from the camera images, the light intensities of each channel are recorded every 0.5 s with refractive index (RI) changes. The performance of the smart phone-based SPR platform for accurate and repeatable measurements was evaluated by detecting different concentrations of antibody binding to a functionalized sensing element, and the experiment results were validated through contrast experiments with a commercial SPR instrument. This cost-effective and portable SPR biosensor based on smart phones has many applications, such as medicine, health and environmental monitoring.

Sensitivity Enhancement of Transition Metal Dichalcogenides/Silicon Nanostructure-based Surface Plasmon Resonance Biosensor

PubMed Central

Ouyang, Qingling; Zeng, Shuwen; Jiang, Li; Hong, Liying; Xu, Gaixia; Dinh, Xuan-Quyen; Qian, Jun; He, Sailing; Qu, Junle; Coquet, Philippe; Yong, Ken-Tye

2016-01-01

In this work, we designed a sensitivity-enhanced surface plasmon resonance biosensor structure based on silicon nanosheet and two-dimensional transition metal dichalcogenides. This configuration contains six components: SF10 triangular prism, gold thin film, silicon nanosheet, two-dimensional MoS2/MoSe2/WS2/WSe2 (defined as MX2) layers, biomolecular analyte layer and sensing medium. The minimum reflectivity, sensitivity as well as the Full Width at Half Maximum of SPR curve are systematically examined by using Fresnel equations and the transfer matrix method in the visible and near infrared wavelength range (600 nm to 1024 nm). The variation of the minimum reflectivity and the change in resonance angle as the function of the number of MX2 layers are presented respectively. The results show that silicon nanosheet and MX2 layers can be served as effective light absorption medium. Under resonance conditions, the electrons in these additional dielectric layers can be transferred to the surface of gold thin film. All silicon-MX2 enhanced sensing models show much better performance than that of the conventional sensing scheme where pure Au thin film is used, the highest sensitivity can be achieved by employing 600 nm excitation light wavelength with 35 nm gold thin film and 7 nm thickness silicon nanosheet coated with monolayer WS2. PMID:27305974

Spectrally pure RF photonic source based on a resonant optical hyper-parametric oscillator

NASA Astrophysics Data System (ADS)

Liang, W.; Eliyahu, D.; Matsko, A. B.; Ilchenko, V. S.; Seidel, D.; Maleki, L.

2014-03-01

We demonstrate a free running 10 GHz microresonator-based RF photonic hyper-parametric oscillator characterized with phase noise better than -60 dBc/Hz at 10 Hz, -90 dBc/Hz at 100 Hz, and -150 dBc/Hz at 10 MHz. The device consumes less than 25 mW of optical power. A correlation between the frequency of the continuous wave laser pumping the nonlinear resonator and the generated RF frequency is confirmed. The performance of the device is compared with the performance of a standard optical fiber based coupled opto-electronic oscillator of OEwaves.

Study of degradation processes kinetics in ohmic contacts of resonant tunneling diodes based on nanoscale AlAs/GaAs heterostructures under influence of temperature

NASA Astrophysics Data System (ADS)

Makeev, M. O.; Meshkov, S. A.

2017-07-01

The artificial aging of resonant tunneling diodes based on nanoscale AlAs/GaAs heterostructures was conducted. As a result of the thermal influence resonant tunneling diodes IV curves degrade firstly due to ohmic contacts' degradation. To assess AlAs/GaAs resonant tunneling diodes degradation level and to predict their reliability, a functional dependence of the contact resistance of resonant tunneling diode AuGeNi ohmic contacts on time and temperature was offered.

Electrically tunable color filter based on a polarization-tailored nano-photonic dichroic resonator featuring an asymmetric subwavelength grating.

PubMed

Park, Chang-Hyun; Yoon, Yeo-Taek; Shrestha, Vivek Raj; Park, Chul-Soon; Lee, Sang-Shin; Kim, Eun-Soo

2013-11-18

We have demonstrated a highly efficient electrically tunable color filter, which provides precise control of color output, taking advantage of a nano-photonic polarization-tailored dichroic resonator combined with a liquid-crystal based polarization rotator. The visible dichroic resonator based on the guided mode resonance, which incorporates a planar dielectric waveguide in Si3N4 integrated with an asymmetric two-dimensional subwavelength Al grating with unequal pitches along its principal axes, exhibited polarization specific transmission featuring high efficiency up to 75%. The proposed tunable color filters were constructed by combining three types of dichroic resonators, each of which deals with a mixture of two primary colors (i.e. blue/green, blue/red, and green/red) with a polarization rotator exploiting a twisted nematic liquid crystal cell. The output colors could be dynamically and seamlessly customized across the blend of the two corresponding primary colors, by altering the polarization via the voltage applied to the polarization rotator. For the blue/red filter, the center wavelength was particularly adjusted from 460 to 610 nm with an applied voltage variation of 2 V, leading to a tuning range of up to 150 nm. And the spectral tuning was readily confirmed via color mapping. The proposed devices may permit the tuning span to be readily extended by tailoring the grating pitches.

Volumetric wireless coil based on periodically coupled split-loop resonators for clinical wrist imaging.

PubMed

Shchelokova, Alena V; van den Berg, Cornelis A T; Dobrykh, Dmitry A; Glybovski, Stanislav B; Zubkov, Mikhail A; Brui, Ekaterina A; Dmitriev, Dmitry S; Kozachenko, Alexander V; Efimtcev, Alexander Y; Sokolov, Andrey V; Fokin, Vladimir A; Melchakova, Irina V; Belov, Pavel A

2018-02-09

Design and characterization of a new inductively driven wireless coil (WLC) for wrist imaging at 1.5 T with high homogeneity operating due to focusing the B 1 field of a birdcage body coil. The WLC design has been proposed based on a volumetric self-resonant periodic structure of inductively coupled split-loop resonators with structural capacitance. The WLC was optimized and studied regarding radiofrequency fields and interaction to the birdcage coil (BC) by electromagnetic simulations. The manufactured WLC was characterized by on-bench measurements and in vivo and phantom study in comparison to a standard cable-connected receive-only coil. The WLC placed into BC gave the measured B1+ increase of the latter by 8.6 times for the same accepted power. The phantom and in vivo wrist imaging showed that the BC in receiving with the WLC inside reached equal or higher signal-to-noise ratio than the conventional clinical setup comprising the transmit-only BC and a commercial receive-only flex-coil and created no artifacts. Simulations and on-bench measurements proved safety in terms of specific absorption rate and reflected transmit power. The results showed that the proposed WLC could be an alternative to standard cable-connected receive coils in clinical magnetic resonance imaging. As an example, with no cable connection, the WLC allowed wrist imaging on a 1.5 T clinical machine using a full-body BC for transmitting and receive with the desired signal-to-noise ratio, image quality, and safety. © 2018 International Society for Magnetic Resonance in Medicine.

Resonator-Based Silicon Electro-Optic Modulator with Low Power Consumption

NASA Astrophysics Data System (ADS)

Xin, Maoqing; Danner, Aaron J.; Eng Png, Ching; Thor Lim, Soon

2009-04-01

This paper demonstrates, via simulation, an electro-optic modulator based on a subwavelength Fabry-Perot resonator cavity with low power consumption of 86 µW/µm. This is, to the best of our knowledge, the lowest power reported for silicon photonic bandgap modulators. The device is modulated at a doped p-i-n junction overlapping the cavity in a silicon waveguide perforated with etched holes, with the doping area optimized for minimum power consumption. The surface area of the entire device is only 2.1 µm2, which compares favorably to other silicon-based modulators. A modulation speed of at least 300 MHz is detected from the electrical simulator after sidewall doping is introduced which is suitable for sensing or fiber to the home (FTTH) technologies, where speed can be traded for low cost and power consumption. The device does not rely on ultra-high Q, and could serve as a sensor, modulator, or passive filter with built-in calibration.

Photonic crystal fiber temperature sensor with high sensitivity based on surface plasmon resonance

NASA Astrophysics Data System (ADS)

Wu, Junjun; Li, Shuguang; shi, Min; Feng, Xinxing

2018-07-01

A high sensitivity photonic crystal fiber (PCF) temperature sensor based on surface plasmon resonance is proposed and evaluated using the finite element method. Besides, the coupling phenomenon is studied. The gold layer deposited on the polishing surface of D-shape PCF is used as the metal to stimulate surface plasma, which can improves the sensitivity. Through exquisite design, the birefringence of the fiber is improved, which makes the loss of y-polarization far greater than the loss of x-polarization. The D-shape fiber avoids filling metal and liquid into the air-holes, which can contact with fluid directly to feel temperature. When the phase matching condition is satisfied, the core mode will couple with the surface plasma mode. The resonance position of y-polarization is very sensitive to the temperature change. The simulation shows that the PCF has high sensitivity of 36.86 nm/°C in y-polarization and wide detection that from 10 °C to 85 °C.

Photon hopping and nanowire based hybrid plasmonic waveguide and ring-resonator

PubMed Central

Gu, Zhiyuan; Liu, Shuai; Sun, Shang; Wang, Kaiyang; Lyu, Quan; Xiao, Shumin; Song, Qinghai

2015-01-01

Nanowire based hybrid plasmonic structure plays an important role in achieving nanodevices, especially for the wide band-gap materials. However, the conventional schemes of nanowire based devices such as nano-resonators are usually isolated from the integrated nano-network and have extremely low quality (Q) factors. Here we demonstrate the transmission of waves across a gap in hybrid plasmonic waveguide, which is termed as “photon hopping”. Based on the photon hopping, we show that the emissions from nanodevices can be efficiently collected and conducted by additional nanowires. The collection ratio can be higher than 50% for a wide range of separation distance, transverse shift, and tilt. Moreover, we have also explored the possibility of improving performances of individual devices by nano-manipulating the nanowire to a pseudo-ring. Our calculations show that both Q factor and Purcell factor have been increased by more than an order of magnitude. We believe that our researches will be essential to forming nanolasers and the following nano-networks.

Linear spreading speeds from nonlinear resonant interaction

NASA Astrophysics Data System (ADS)

Faye, Grégory; Holzer, Matt; Scheel, Arnd

2017-06-01

We identify a new mechanism for propagation into unstable states in spatially extended systems, that is based on resonant interaction in the leading edge of invasion fronts. Such resonant invasion speeds can be determined solely based on the complex linear dispersion relation at the unstable equilibrium, but rely on the presence of a nonlinear term that facilitates the resonant coupling. We prove that these resonant speeds give the correct invasion speed in a simple example, we show that fronts with speeds slower than the resonant speed are unstable, and corroborate our speed criterion numerically in a variety of model equations, including a nonlocal scalar neural field model. GF received support from the project NONLOCAL (ANR-14-CE25-0013) funded by the French National Research Agency. MH was partially supported by the National Science Foundation through grant NSF-DMS-1516155. AS was partially supported by the National Science Foundation through grant NSF-DMS-1311740 and through a DAAD Fellowship.

Surface plasmon resonance sensor based on photonic crystal fiber filled with gold-silica-gold multilayer nanoshells

NASA Astrophysics Data System (ADS)

Liu, Baolin; Lu, Ying; Yang, Xianchao; Yao, Jianquan

2017-12-01

We present a surface plasmon resonance sensor based on photonic crystal fiber filled with gold-silica-gold (GSG) multilayer nanoshells for measurement of the refractive index of liquid analyte. The GSG multilayer nanoshells, composed of a silica-coated gold nanosphere surrounded by a gold shell layer, are designed to be the functional material of the sensor because of their attractive optical properties. Two resonant peaks are obtained due to the hybridization of nanosphere plasmon modes and nanoshell plasmon modes. It is demonstrated that the resonant wavelength of the two peaks can be precisely tuned in 560-716 nm and 849-2485 nm, respectively, by varying the structural parameters of the GSG multilayer nanoshells in a compact, sub-200 nm size range. The excellent spectral tunability makes the sensor attractive in a wide range of applications, especially in biosensing in near-infrared region. Furthermore, the influences of the parameters on the performance of the sensor are systematically simulated and discussed. It is observed that the spectral sensitivities of 1894.3 nm/RIU and 3011.4 nm/RIU can be achieved respectively by the two resonant peaks in the sensing range of 1.33-1.38. The existence of two loss peaks also provides the possibility to realize self-reference in the sensing process.

Integrated optics ring-resonator chemical sensor with polymer transduction layer

NASA Technical Reports Server (NTRS)

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

2004-01-01

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

Accurate classification of brain gliomas by discriminate dictionary learning based on projective dictionary pair learning of proton magnetic resonance spectra.

PubMed

Adebileje, Sikiru Afolabi; Ghasemi, Keyvan; Aiyelabegan, Hammed Tanimowo; Saligheh Rad, Hamidreza

2017-04-01

Proton magnetic resonance spectroscopy is a powerful noninvasive technique that complements the structural images of cMRI, which aids biomedical and clinical researches, by identifying and visualizing the compositions of various metabolites within the tissues of interest. However, accurate classification of proton magnetic resonance spectroscopy is still a challenging issue in clinics due to low signal-to-noise ratio, overlapping peaks of metabolites, and the presence of background macromolecules. This paper evaluates the performance of a discriminate dictionary learning classifiers based on projective dictionary pair learning method for brain gliomas proton magnetic resonance spectroscopy spectra classification task, and the result were compared with the sub-dictionary learning methods. The proton magnetic resonance spectroscopy data contain a total of 150 spectra (74 healthy, 23 grade II, 23 grade III, and 30 grade IV) from two databases. The datasets from both databases were first coupled together, followed by column normalization. The Kennard-Stone algorithm was used to split the datasets into its training and test sets. Performance comparison based on the overall accuracy, sensitivity, specificity, and precision was conducted. Based on the overall accuracy of our classification scheme, the dictionary pair learning method was found to outperform the sub-dictionary learning methods 97.78% compared with 68.89%, respectively. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

A tunable optical Kerr switch based on a nanomechanical resonator coupled to a quantum dot.

PubMed

Li, Jin-Jin; Zhu, Ka-Di

2010-05-21

We have theoretically demonstrated the large enhancement of the optical Kerr effect in a scheme of a nanomechanical resonator coupled to a quantum dot and shown that this phenomenon can be used to realize a fast optical Kerr switch by turning the control field on or off. Due to the vibration of the nanoresonator, as we pump on the strong control beam, the optical spectrum shows that the magnitude of this optical Kerr effect is proportional to the intensity of the control field. In this case, a fast and tunable optical Kerr switch can be implemented easily by an intensity-adjustable laser. Based on this tunable optical Kerr switch, we also provide a detection method to measure the frequency of the nanomechanical resonator in this coupled system.

Resonant metamaterial detectors based on THz quantum-cascade structures

PubMed Central

Benz, A.; Krall, M.; Schwarz, S.; Dietze, D.; Detz, H.; Andrews, A. M.; Schrenk, W.; Strasser, G.; Unterrainer, K.

2014-01-01

We present the design, fabrication and characterisation of an intersubband detector employing a resonant metamaterial coupling structure. The semiconductor heterostructure relies on a conventional THz quantum-cascade laser design and is operated at zero bias for the detector operation. The same active region can be used to generate or detect light depending on the bias conditions and the vertical confinement. The metamaterial is processed directly into the top metal contact and is used to couple normal incidence radiation resonantly to the intersubband transitions. The device is capable of detecting light below and above the reststrahlenband of gallium-arsenide corresponding to the mid-infrared and THz spectral region. PMID:24608677

Tunable resonant and non-resonant interactions between a phase qubit and LC resonator

NASA Astrophysics Data System (ADS)

Allman, Michael Shane; Whittaker, Jed D.; Castellanos-Beltran, Manuel; Cicak, Katarina; da Silva, Fabio; Defeo, Michael; Lecocq, Florent; Sirois, Adam; Teufel, John; Aumentado, Jose; Simmonds, Raymond W.

2014-03-01

We use a flux-biased radio frequency superconducting quantum interference device (rf SQUID) with an embedded flux-biased direct current (dc) SQUID to generate strong resonant and non-resonant tunable interactions between a phase qubit and a lumped-element resonator. The rf-SQUID creates a tunable magnetic susceptibility between the qubit and resonator providing resonant coupling rates from zero to near the ultra-strong coupling regime. By modulating the magnetic susceptibility, non-resonant parametric coupling achieves rates > 100 MHz . Nonlinearity of the magnetic susceptibility also leads to parametric coupling at subharmonics of the qubit-resonator detuning. Controllable coupling is generically important for constructing coupled-mode systems ubiquitous in physics, useful for both, quantum information architectures and quantum simulators. This work supported by NIST and NSA grant EAO140639.

Dual-band wide-angle metamaterial perfect absorber based on the combination of localized surface plasmon resonance and Helmholtz resonance.

PubMed

Zhang, Changlei; Huang, Cheng; Pu, Mingbo; Song, Jiakun; Zhao, Zeyu; Wu, Xiaoyu; Luo, Xiangang

2017-07-18

In this article, a dual-band wide-angle metamaterial perfect absorber is proposed to achieve absorption at the wavelength where laser radar operates. It is composed of gold ring array and a Helmholtz resonance cavity spaced by a Si dielectric layer. Numerical simulation results reveal that the designed absorber displays two absorption peaks at the target wavelength of 10.6 μm and 1.064 μm with the large frequency ratio and near-unity absorptivity under the normal incidence. The wide-angle absorbing property and the polarization-insensitive feature are also demonstrated. Localized surface plasmons resonance and Helmholtz resonance are introduced to analyze and interpret the absorbing mechanism. The designed perfect absorber can be developed for potential applications in infrared stealth field.

Nonlinear elasticity in resonance experiments

NASA Astrophysics Data System (ADS)

Li, Xun; Sens-Schönfelder, Christoph; Snieder, Roel

2018-04-01

Resonant bar experiments have revealed that dynamic deformation induces nonlinearity in rocks. These experiments produce resonance curves that represent the response amplitude as a function of the driving frequency. We propose a model to reproduce the resonance curves with observed features that include (a) the log-time recovery of the resonant frequency after the deformation ends (slow dynamics), (b) the asymmetry in the direction of the driving frequency, (c) the difference between resonance curves with the driving frequency that is swept upward and downward, and (d) the presence of a "cliff" segment to the left of the resonant peak under the condition of strong nonlinearity. The model is based on a feedback cycle where the effect of softening (nonlinearity) feeds back to the deformation. This model provides a unified interpretation of both the nonlinearity and slow dynamics in resonance experiments. We further show that the asymmetry of the resonance curve is caused by the softening, which is documented by the decrease of the resonant frequency during the deformation; the cliff segment of the resonance curve is linked to a bifurcation that involves a steep change of the response amplitude when the driving frequency is changed. With weak nonlinearity, the difference between the upward- and downward-sweeping curves depends on slow dynamics; a sufficiently slow frequency sweep eliminates this up-down difference. With strong nonlinearity, the up-down difference results from both the slow dynamics and bifurcation; however, the presence of the bifurcation maintains the respective part of the up-down difference, regardless of the sweep rate.

A new quadrature annular resonator for 3 T MRI based on artificial-dielectrics.

PubMed

Mikhailovskaya, Anna A; Shchelokova, Alena V; Dobrykh, Dmitry A; Sushkov, Ivan V; Slobozhanyuk, Alexey P; Webb, Andrew

2018-06-01

Dielectric resonators have previously been constructed for ultra-high frequency magnetic resonance imaging and microscopy. However, it is challenging to design these dielectric resonators at clinical field strengths due to their intrinsically large dimensions, especially when using materials with moderate permittivity. Here we propose and characterize a novel approach using artificial-dielectrics which reduces substantially the required outer diameter of the resonator. For a resonator designed to operate in a 3 Tesla scanner using water as the dielectric, a reduction in outer diameter of 37% was achieved. When used in an inductively-coupled wireless mode, the sensitivity of the artificial-dielectric resonator was measured to be slightly higher than that of a standard dielectric resonator operating in its degenerate circularly-polarized hybrid electromagnetic modes (HEM 11 ). This study demonstrates the first application of an artificial-dielectric approach to MR volume coil design. Copyright © 2018 Elsevier Inc. All rights reserved.

High Resolution and Large Dynamic Range Resonant Pressure Sensor Based on Q-Factor Measurement

NASA Technical Reports Server (NTRS)

Gutierrez, Roman C. (Inventor); Stell, Christopher B. (Inventor); Tang, Tony K. (Inventor); Vorperian, Vatche (Inventor); Wilcox, Jaroslava (Inventor); Shcheglov, Kirill (Inventor); Kaiser, William J. (Inventor)

2000-01-01

A pressure sensor has a high degree of accuracy over a wide range of pressures. Using a pressure sensor relying upon resonant oscillations to determine pressure, a driving circuit drives such a pressure sensor at resonance and tracks resonant frequency and amplitude shifts with changes in pressure. Pressure changes affect the Q-factor of the resonating portion of the pressure sensor. Such Q-factor changes are detected by the driving/sensing circuit which in turn tracks the changes in resonant frequency to maintain the pressure sensor at resonance. Changes in the Q-factor are reflected in changes of amplitude of the resonating pressure sensor. In response, upon sensing the changes in the amplitude, the driving circuit changes the force or strength of the electrostatic driving signal to maintain the resonator at constant amplitude. The amplitude of the driving signals become a direct measure of the changes in pressure as the operating characteristics of the resonator give rise to a linear response curve for the amplitude of the driving signal. Pressure change resolution is on the order of 10(exp -6) torr over a range spanning from 7,600 torr to 10(exp -6) torr. No temperature compensation for the pressure sensor of the present invention is foreseen. Power requirements for the pressure sensor are generally minimal due to the low-loss mechanical design of the resonating pressure sensor and the simple control electronics.

Resonance-Based Time-Frequency Manifold for Feature Extraction of Ship-Radiated Noise.

PubMed

Yan, Jiaquan; Sun, Haixin; Chen, Hailan; Junejo, Naveed Ur Rehman; Cheng, En

2018-03-22

In this paper, a novel time-frequency signature using resonance-based sparse signal decomposition (RSSD), phase space reconstruction (PSR), time-frequency distribution (TFD) and manifold learning is proposed for feature extraction of ship-radiated noise, which is called resonance-based time-frequency manifold (RTFM). This is suitable for analyzing signals with oscillatory, non-stationary and non-linear characteristics in a situation of serious noise pollution. Unlike the traditional methods which are sensitive to noise and just consider one side of oscillatory, non-stationary and non-linear characteristics, the proposed RTFM can provide the intact feature signature of all these characteristics in the form of a time-frequency signature by the following steps: first, RSSD is employed on the raw signal to extract the high-oscillatory component and abandon the low-oscillatory component. Second, PSR is performed on the high-oscillatory component to map the one-dimensional signal to the high-dimensional phase space. Third, TFD is employed to reveal non-stationary information in the phase space. Finally, manifold learning is applied to the TFDs to fetch the intrinsic non-linear manifold. A proportional addition of the top two RTFMs is adopted to produce the improved RTFM signature. All of the case studies are validated on real audio recordings of ship-radiated noise. Case studies of ship-radiated noise on different datasets and various degrees of noise pollution manifest the effectiveness and robustness of the proposed method.

Resonance-Based Time-Frequency Manifold for Feature Extraction of Ship-Radiated Noise

PubMed Central

Yan, Jiaquan; Sun, Haixin; Chen, Hailan; Junejo, Naveed Ur Rehman; Cheng, En

2018-01-01

In this paper, a novel time-frequency signature using resonance-based sparse signal decomposition (RSSD), phase space reconstruction (PSR), time-frequency distribution (TFD) and manifold learning is proposed for feature extraction of ship-radiated noise, which is called resonance-based time-frequency manifold (RTFM). This is suitable for analyzing signals with oscillatory, non-stationary and non-linear characteristics in a situation of serious noise pollution. Unlike the traditional methods which are sensitive to noise and just consider one side of oscillatory, non-stationary and non-linear characteristics, the proposed RTFM can provide the intact feature signature of all these characteristics in the form of a time-frequency signature by the following steps: first, RSSD is employed on the raw signal to extract the high-oscillatory component and abandon the low-oscillatory component. Second, PSR is performed on the high-oscillatory component to map the one-dimensional signal to the high-dimensional phase space. Third, TFD is employed to reveal non-stationary information in the phase space. Finally, manifold learning is applied to the TFDs to fetch the intrinsic non-linear manifold. A proportional addition of the top two RTFMs is adopted to produce the improved RTFM signature. All of the case studies are validated on real audio recordings of ship-radiated noise. Case studies of ship-radiated noise on different datasets and various degrees of noise pollution manifest the effectiveness and robustness of the proposed method. PMID:29565288

Phosphorous magnetic resonance spectroscopy-based skeletal muscle bioenergetic studies in subclinical hypothyroidism.

PubMed

Rana, P; Sripathy, G; Varshney, A; Kumar, P; Devi, M Memita; Marwaha, R K; Tripathi, R P; Khushu, S

2012-02-01

Subclinical hypothyroidism (sHT) is considered to be a milder form of thyroid dysfunction. Few earlier studies have reported neuromuscular symptoms as well as impaired muscle metabolism in sHT patients. In this study we report our findings on muscle bioenergetics in sHT patients using phosphorous magnetic resonance spectroscopy (31P MRS) and look upon the possibility to use 31P MRS technique as a clinical marker for monitoring muscle function in subclinical thyroid dysfunction. Seventeen normal subjects, 15 patients with sHT, and 9 patients with hypothyroidism performed plantar flexion exercise while lying supine in 1.5 T magnetic resonance scanner using custom built exercise device. MR Spectroscopy measurements of inorganic phosphate (Pi), phosphocreatine (PCr), and ATP of the calf muscle were taken during rest, at the end of exercise and in the recovery phase. PCr recovery rate constant (kPCr) and oxidative capacity were calculated by monoexponential fit of PCr vs time (t) at the beginning of recovery. We observed that changes in some of the phosphometabolites (increased phosphodiester levels and Pi concentration) in sHT patients which were similar to those detected in patients with hypothyroidism. However, our results do not demonstrate impaired muscle oxidative metabolism in sHT patients based upon PCr dynamics as observed in hypothyroid patients. 31P MRS-based PCr recovery rate could be used as a marker for monitoring muscle oxidative metabolism in sub clinical thyroid dysfunction.

Integrated narrowband optical filter based on embedded subwavelength resonant grating structures

DOEpatents

Grann, Eric B.; Sitter, Jr., David N.

2000-01-01

A resonant grating structure in a waveguide and methods of tuning the performance of the grating structure are described. An apparatus includes a waveguide; and a subwavelength resonant grating structure embedded in the waveguide. The systems and methods provide advantages including narrowband filtering capabilities, minimal sideband reflections, spatial control, high packing density, and tunability.

Upconversion nanoparticle-based fluorescence resonance energy transfer assay for organophosphorus pesticides.

PubMed

Long, Qian; Li, Haitao; Zhang, Youyu; Yao, Shouzhuo

2015-06-15

This paper reports a novel nanosensor for organophosphorus pesticides based on the fluorescence resonance energy transfer (FRET) between NaYF4:Yb,Er upconversion nanoparticles (UCNPs) and gold nanoparticles (AuNPs). The detection mechanism is based on the facts that AuNPs quench the fluorescence of UCNPs and organophosphorus pesticides (OPs) inhibit the activity of acetylcholinesterase (AChE) which catalyzes the hydrolysis of acetylthiocholine (ATC) into thiocholine. Under the optimized conditions, the logarithm of the pesticides concentration was proportional to the inhibition efficiency. The detection limits of parathion-methyl, monocrotophos and dimethoate reached 0.67, 23, and 67 ng/L, respectively. Meanwhile, the biosensor shows good sensitivity, stability, and could be successfully applied to detection of OPs in real food samples, suggesting the biosensor has potentially extensive application clinic diagnoses assays. Copyright © 2014 Elsevier B.V. All rights reserved.

Novel threshold pressure sensors based on nonlinear dynamics of MEMS resonators

NASA Astrophysics Data System (ADS)

Hasan, Mohammad H.; Alsaleem, Fadi M.; Ouakad, Hassen M.

2018-06-01

Triggering an alarm in a car for low air-pressure in the tire or tripping an HVAC compressor if the refrigerant pressure is lower than a threshold value are examples for applications where measuring the amount of pressure is not as important as determining if the pressure has exceeded a threshold value for an action to occur. Unfortunately, current technology still relies on analog pressure sensors to perform this functionality by adding a complex interface (extra circuitry, controllers, and/or decision units). In this paper, we demonstrate two new smart tunable-threshold pressure switch concepts that can reduce the complexity of a threshold pressure sensor. The first concept is based on the nonlinear subharmonic resonance of a straight double cantilever microbeam with a proof mass and the other concept is based on the snap-through bi-stability of a clamped-clamped MEMS shallow arch. In both designs, the sensor operation concept is simple. Any actuation performed at a certain pressure lower than a threshold value will activate a nonlinear dynamic behavior (subharmonic resonance or snap-through bi-stability) yielding a large output that would be interpreted as a logic value of ONE, or ON. Once the pressure exceeds the threshold value, the nonlinear response ceases to exist, yielding a small output that would be interpreted as a logic value of ZERO, or OFF. A lumped, single degree of freedom model for the double cantilever beam, that is validated using experimental data, and a continuous beam model for the arch beam, are used to simulate the operation range of the proposed sensors by identifying the relationship between the excitation signal and the critical cut-off pressure.

Refractive index-based detection of gradient elution liquid chromatography using chip-integrated microring resonator arrays.

PubMed

Wade, James H; Bailey, Ryan C

2014-01-07

Refractive index-based sensors offer attractive characteristics as nondestructive and universal detectors for liquid chromatographic separations, but a small dynamic range and sensitivity to minor thermal perturbations limit the utility of commercial RI detectors for many potential applications, especially those requiring the use of gradient elutions. As such, RI detectors find use almost exclusively in sample abundant, isocratic separations when interfaced with high-performance liquid chromatography. Silicon photonic microring resonators are refractive index-sensitive optical devices that feature good sensitivity and tremendous dynamic range. The large dynamic range of microring resonators allows the sensors to function across a wide spectrum of refractive indices, such as that encountered when moving from an aqueous to organic mobile phase during a gradient elution, a key analytical advantage not supported in commercial RI detectors. Microrings are easily configured into sensor arrays, and chip-integrated control microrings enable real-time corrections of thermal drift. Thermal controls allow for analyses at any temperature and, in the absence of rigorous temperature control, obviates extended detector equilibration wait times. Herein, proof of concept isocratic and gradient elution separations were performed using well-characterized model analytes (e.g., caffeine, ibuprofen) in both neat buffer and more complex sample matrices. These experiments demonstrate the ability of microring arrays to perform isocratic and gradient elutions under ambient conditions, avoiding two major limitations of commercial RI-based detectors and maintaining comparable bulk RI sensitivity. Further benefit may be realized in the future through selective surface functionalization to impart degrees of postcolumn (bio)molecular specificity at the detection phase of a separation. The chip-based and microscale nature of microring resonators also make it an attractive potential detection

Buried anti resonant reflecting optical waveguide based on porous silicon material for an integrated Mach Zehnder structure

NASA Astrophysics Data System (ADS)

Hiraoui, M.; Guendouz, M.; Lorrain, N.; Haji, L.; Oueslati, M.

2012-11-01

A buried anti resonant reflecting optical waveguide for an integrated Mach Zehnder structure based on porous silicon material is achieved using a classical photolithography process. Three distinct porous silicon layers are then elaborated in a single step, by varying the porosity (thus the refractive index) and the thickness while respecting the anti-resonance conditions. Simulations and experimental results clearly show the antiresonant character of the buried waveguides. Significant variation of the reflectance and light propagation with different behavior depending on the polarization and the Mach Zehnder dimensions is obtained. Finally, we confirm the feasibility of this structure for sensing applications.

Ultrasonic signal enhancement by resonator techniques

NASA Technical Reports Server (NTRS)

Heyman, J. S.

1973-01-01

Ultrasonic resonators increase experimental sensitivity to acoustic dispersion and changes in attenuation. Experimental sensitivity enhancement line shapes are presented which were obtained by modulating the acoustic properties of a CdS resonator with a light beam. Small changes in light level are made to produce almost pure absorptive or dispersive changes in the resonator signal. This effect is due to the coupling of the ultrasonic wave to the CdS conductivity which is proportional to incident light intensity. The resonator conductivity is adjusted in this manner to obtain both dispersive and absorptive sensitivity enhancement line shapes. The data presented verify previous thoretical calculations based on a propagating wave model.

Tapered optical fiber sensor based on localized surface plasmon resonance.

PubMed

Lin, Hsing-Ying; Huang, Chen-Han; Cheng, Gia-Ling; Chen, Nan-Kuang; Chui, Hsiang-Chen

2012-09-10

A tapered fiber localized surface plasmon resonance (LSPR) sensor is demonstrated for refractive index sensing and label-free biochemical detection. The sensing strategy relies on the interrogation of the transmission intensity change due to the evanescent field absorption of immobilized gold nanoparticles on the tapered fiber surface. The refractive index resolution based on the interrogation of transmission intensity change is calculated to be 3.2×10⁻⁵ RIU. The feasibility of DNP-functionalized tapered fiber LSPR sensor in monitoring anti-DNP antibody with different concentrations spiked in buffer is examined. Results suggest that the compact sensor can perform qualitative and quantitative biochemical detection in real-time and thus has potential to be used in biomolecular sensing applications.

Tunable room temperature THz sources based on nonlinear mixing in a hybrid optical and THz micro-ring resonator.

PubMed

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

2015-03-24

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

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

PubMed Central

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

2015-01-01

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

All-dielectric frequency selective surface design based on dielectric resonator

NASA Astrophysics Data System (ADS)

Zheng-Bin, Wang; Chao, Gao; Bo, Li; Zhi-Hang, Wu; Hua-Mei, Zhang; Ye-Rong, Zhang

2016-06-01

In this work, we propose an all-dielectric frequency selective surface (FSS) composed of periodically placed high-permittivity dielectric resonators and a three-dimensional (3D) printed supporter. Mie resonances in the dielectric resonators offer strong electric and magnetic dipoles, quadrupoles, and higher order terms. The re-radiated electric and magnetic fields by these multipoles interact with the incident fields, which leads to total reflection or total transmission in some special frequency bands. The measured results of the fabricated FSS demonstrate a stopband fractional bandwidth (FBW) of 22.2%, which is consistent with the simulated result. Project supported by the National Natural Science Foundation of China (Grant Nos. 61201030, 61372045, 61472045, and 61401229), the Science and Technology Project of Jiangsu Province, China (Grant No. BE2015002), the Open Research Program of the State Key Laboratory of Millimeter Waves, China (Grant Nos. K201616 and K201622), and the Nanjing University of Posts and Telecommunications Scientific Foundation, China (Grant No. NY214148).

Improved Biomolecular Thin-Film Sensor based on Plasmon Waveguide Resonance

NASA Astrophysics Data System (ADS)

Byard, Courtney; Aslan, Mustafa; Mendes, Sergio

2009-05-01

The design, fabrication, and characterization of a plasmon waveguide resonance (PWR) sensor are presented. Glass substrates are coated with a 35 nm gold film using electron beam evaporation, and then covered with a 143 nm aluminum oxide waveguide using an atomic layer deposition process, creating a smooth, highly transparent dielectric film. When probed in the Kretschmann configuration, the structure allows for an efficient conversion of an incident optical beam into a surface wave, which is mainly confined in the dielectric layer and exhibits a deep and narrow angular resonance. The performance (reflectance vs. incidence angle in TE polarization) is modeled using a transfer-matrix approach implemented into a Mathematica code. Our simulations and experimental data are compared with that of surface plasmon resonance (SPR) sensor using the same criteria. We show that the resolution of PWR is approximately ten times better than SPR, opening opportunities for more sensitive studies in various applications including research in protein interactions, pharmaceutical drug development, and food analysis.

Resonance energy transfer process in nanogap-based dual-color random lasing

NASA Astrophysics Data System (ADS)

Shi, Xiaoyu; Tong, Junhua; Liu, Dahe; Wang, Zhaona

2017-04-01

The resonance energy transfer (RET) process between Rhodamine 6G and oxazine in the nanogap-based random systems is systematically studied by revealing the variations and fluctuations of RET coefficients with pump power density. Three working regions stable fluorescence, dynamic laser, and stable laser are thus demonstrated in the dual-color random systems. The stable RET coefficients in fluorescence and lasing regions are generally different and greatly dependent on the donor concentration and the donor-acceptor ratio. These results may provide a way to reveal the energy distribution regulars in the random system and to design the tunable multi-color coherent random lasers for colorful imaging.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Samanta, C.; Yasasvi Gangavarapu, P. R.; Naik, A. K.

Atomically thin two dimensional (2D) layered materials have emerged as a new class of material for nanoelectromechanical systems (NEMS) due to their extraordinary mechanical properties and ultralow mass density. Among them, graphene has been the material of choice for nanomechanical resonator. However, recent interest in 2D chalcogenide compounds has also spurred research in using materials such as MoS{sub 2} for the NEMS applications. As the dimensions of devices fabricated using these materials shrink down to atomically thin membrane, strain and nonlinear effects have become important. A clear understanding of the nonlinear effects and the ability to manipulate them is essentialmore » for next generation sensors. Here, we report on all electrical actuation and detection of few-layer MoS{sub 2} resonator. The ability to electrically detect multiple modes and actuate the modes deep into the nonlinear regime enables us to probe the nonlinear coupling between various vibrational modes. The modal coupling in our device is strong enough to detect three distinct internal resonances.« less

1.05-GHz CMOS oscillator based on lateral- field-excited piezoelectric AlN contour- mode MEMS resonators.

PubMed

Zuo, Chengjie; Van der Spiegel, Jan; Piazza, Gianluca

2010-01-01

This paper reports on the first demonstration of a 1.05-GHz microelectromechanical (MEMS) oscillator based on lateral-field-excited (LFE) piezoelectric AlN contourmode resonators. The oscillator shows a phase noise level of -81 dBc/Hz at 1-kHz offset frequency and a phase noise floor of -146 dBc/Hz, which satisfies the global system for mobile communications (GSM) requirements for ultra-high frequency (UHF) local oscillators (LO). The circuit was fabricated in the AMI semiconductor (AMIS) 0.5-microm complementary metaloxide- semiconductor (CMOS) process, with the oscillator core consuming only 3.5 mW DC power. The device overall performance has the best figure-of-merit (FoM) when compared with other gigahertz oscillators that are based on film bulk acoustic resonator (FBAR), surface acoustic wave (SAW), and CMOS on-chip inductor and capacitor (CMOS LC) technologies. A simple 2-mask process was used to fabricate the LFE AlN resonators operating between 843 MHz and 1.64 GHz with simultaneously high Q (up to 2,200) and kt 2 (up to 1.2%). This process further relaxes manufacturing tolerances and improves yield. All these advantages make these devices suitable for post-CMOS integrated on-chip direct gigahertz frequency synthesis in reconfigurable multiband wireless communications.

Properties of regular polygons of coupled microring resonators.

PubMed

Chremmos, Ioannis; Uzunoglu, Nikolaos

2007-11-01

The resonant properties of a closed and symmetric cyclic array of N coupled microring resonators (coupled-microring resonator regular N-gon) are for the first time determined analytically by applying the transfer matrix approach and Floquet theorem for periodic propagation in cylindrically symmetric structures. By solving the corresponding eigenvalue problem with the field amplitudes in the rings as eigenvectors, it is shown that, for even or odd N, this photonic molecule possesses 1 + N/2 or 1+N resonant frequencies, respectively. The condition for resonances is found to be identical to the familiar dispersion equation of the infinite coupled-microring resonator waveguide with a discrete wave vector. This result reveals the so far latent connection between the two optical structures and is based on the fact that, for a regular polygon, the field transfer matrix over two successive rings is independent of the polygon vertex angle. The properties of the resonant modes are discussed in detail using the illustration of Brillouin band diagrams. Finally, the practical application of a channel-dropping filter based on polygons with an even number of rings is also analyzed.

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

NASA Astrophysics Data System (ADS)

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

2009-11-01

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

Rapid analysis of protein backbone resonance assignments using cryogenic probes, a distributed Linux-based computing architecture, and an integrated set of spectral analysis tools.

PubMed

Monleón, Daniel; Colson, Kimberly; Moseley, Hunter N B; Anklin, Clemens; Oswald, Robert; Szyperski, Thomas; Montelione, Gaetano T

2002-01-01

Rapid data collection, spectral referencing, processing by time domain deconvolution, peak picking and editing, and assignment of NMR spectra are necessary components of any efficient integrated system for protein NMR structure analysis. We have developed a set of software tools designated AutoProc, AutoPeak, and AutoAssign, which function together with the data processing and peak-picking programs NMRPipe and Sparky, to provide an integrated software system for rapid analysis of protein backbone resonance assignments. In this paper we demonstrate that these tools, together with high-sensitivity triple resonance NMR cryoprobes for data collection and a Linux-based computer cluster architecture, can be combined to provide nearly complete backbone resonance assignments and secondary structures (based on chemical shift data) for a 59-residue protein in less than 30 hours of data collection and processing time. In this optimum case of a small protein providing excellent spectra, extensive backbone resonance assignments could also be obtained using less than 6 hours of data collection and processing time. These results demonstrate the feasibility of high throughput triple resonance NMR for determining resonance assignments and secondary structures of small proteins, and the potential for applying NMR in large scale structural proteomics projects.

Base pair mismatch recognition using plasmon resonant particle labels.

PubMed

Oldenburg, Steven J; Genick, Christine C; Clark, Keith A; Schultz, David A

2002-10-01

We demonstrate the use of silver plasmon resonant particles (PRPs), as reporter labels, in a microarray-based DNA hybridization assay in which we screen for a known polymorphic site in the breast cancer gene BRCA1. PRPs (40-100 nm in diameter) image as diffraction-limited points of colored light in a standard microscope equipped with dark-field illumination, and can be individually identified and discriminated against background scatter. Rather than overall intensity, the number of PRPs counted in a CCD image by a software algorithm serves as the signal in these assays. In a typical PRP hybridization assay, we achieve a detection sensitivity that is approximately 60 x greater than that achieved by using fluorescent labels. We conclude that single particle counting is robust, generally applicable to a wide variety of assay platforms, and can be integrated into low-cost and quantitative detection systems for single nucleotide polymorphism analysis.

Monaural Sound Localization Based on Structure-Induced Acoustic Resonance

PubMed Central

Kim, Keonwook; Kim, Youngwoong

2015-01-01

A physical structure such as a cylindrical pipe controls the propagated sound spectrum in a predictable way that can be used to localize the sound source. This paper designs a monaural sound localization system based on multiple pyramidal horns around a single microphone. The acoustic resonance within the horn provides a periodicity in the spectral domain known as the fundamental frequency which is inversely proportional to the radial horn length. Once the system accurately estimates the fundamental frequency, the horn length and corresponding angle can be derived by the relationship. The modified Cepstrum algorithm is employed to evaluate the fundamental frequency. In an anechoic chamber, localization experiments over azimuthal configuration show that up to 61% of the proper signal is recognized correctly with 30% misfire. With a speculated detection threshold, the system estimates direction 52% in positive-to-positive and 34% in negative-to-positive decision rate, on average. PMID:25668214

Cylindrical optical resonators: fundamental properties and bio-sensing characteristics

NASA Astrophysics Data System (ADS)

Khozeymeh, Foroogh; Razaghi, Mohammad

2018-04-01

In this paper, detailed theoretical analysis of cylindrical resonators is demonstrated. As illustrated, these kinds of resonators can be used as optical bio-sensing devices. The proposed structure is analyzed using an analytical method based on Lam's approximation. This method is systematic and has simplified the tedious process of whispering-gallery mode (WGM) wavelength analysis in optical cylindrical biosensors. By this method, analysis of higher radial orders of high angular momentum WGMs has been possible. Using closed-form analytical equations, resonance wavelengths of higher radial and angular order WGMs of TE and TM polarization waves are calculated. It is shown that high angular momentum WGMs are more appropriate for bio-sensing applications. Some of the calculations are done using a numerical non-linear Newton method. A perfect match of 99.84% between the analytical and the numerical methods has been achieved. In order to verify the validity of the calculations, Meep simulations based on the finite difference time domain (FDTD) method are performed. In this case, a match of 96.70% between the analytical and FDTD results has been obtained. The analytical predictions are in good agreement with other experimental work (99.99% match). These results validate the proposed analytical modelling for the fast design of optical cylindrical biosensors. It is shown that by extending the proposed two-layer resonator structure analyzing scheme, it is possible to study a three-layer cylindrical resonator structure as well. Moreover, by this method, fast sensitivity optimization in cylindrical resonator-based biosensors has been possible. Sensitivity of the WGM resonances is analyzed as a function of the structural parameters of the cylindrical resonators. Based on the results, fourth radial order WGMs, with a resonator radius of 50 μm, display the most bulk refractive index sensitivity of 41.50 (nm/RIU).

LABCOM resonator Phase 3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keres, L.J.

1990-11-01

The purpose of this project was to develop quartz crystal resonator designs, production processes, and test capabilities for 5-MHz, 6.2-MHz, and 10-MHz resonators for Tactical Miniature Crystal Oscillator (TMXO) applications. GE Neutron Devices (GEND) established and demonstrated the capability to produce and test quartz crystal resonators for use in the TMXO developed by the US Army ERADCOM (now LABCOM). The goals in this project were based on the ERADCOM statement of work. The scope of work indicated that the resonator production facilities for this project would not be completely independent, but that they would be supported in part by equipmentmore » and processes in place at GEND used in US Department of Energy (DOE) work. In addition, provisions for production test equipment or or eventual technology transfer costs to a commercial supplier were clearly excluded from the scope of work. The demonstrated technical capability of the deep-etched blank design is feasible and practical. It can be manufactured in quantity with reasonable yield, and its performance is readily predictable. The ceramic flatpack is a very strong package with excellent hermeticity. The four-point mount supports the crystal to reasonable shock levels and does not perturb the resonator's natural frequency-temperature behavior. The package can be sealed with excellent yields. The high-temperature, high-vacuum processing developed for the TMXO resonator, including bonding the piezoid to its mount with conductive polyimide adhesive, is consistent with precision resonator fabrication. 1 fig., 6 tabs.« less

Developing ultrasensitive pressure sensor based on graphene nanoribbon: Molecular dynamics simulation

NASA Astrophysics Data System (ADS)

Kwon, Oh Kuen; Lee, Jun Ha; Kim, Ki-Sub; Kang, Jeong Won

2013-01-01

We propose schematics for an ultra-sensitive pressure sensor based on graphene-nanoribbon (GNR) and investigate its electromechanical properties using classical molecular dynamics simulations and piezo-electricity theory. Since the top plate applied to the actual pressure is large whereas the contact area on the GNR is very small, both the sensitivity and the sensing range can be adjusted by controlling the aspect ratio between the top plate and the contact point areas. Our calculation shows that the electrical conductivity of GNRs can be tuned by the applied pressure and the electric conductance of the deflected GNR linearly increases with increasing applied pressure for the linear elastic region in low pressure below the cut-off point. In the curves for both the deflection and potential energy, the linear elastic regime in low pressure was explicitly separated with the non-linear elastic regime in high pressure. The proposed GNR-based nanoelectromechanical devices have great potential for application as electromechanical memory, relay or switching devices.

Two objects in Neptune's 9:1 resonance -- implications for resonance sticking in the scattering population

NASA Astrophysics Data System (ADS)

Volk, Kathryn; Murray-Clay, Ruth; Gladman, Brett; Lawler, Samantha; Yu, Tze Yeung Mathew; Alexandersen, Mike; Bannister, Michele; Chen, Ying-Yung; Dawson, Rebekah; Greenstreet, Sarah; Gwyn, Stephen; Kavelaars, J. J.; Lin, Hsing Wen; Lykawka, Patryk; Petit, Jean-Marc

2018-04-01

We discuss the detection in the Outer Solar System Origins Survey (OSSOS) of two objects in Neptune's distant 9:1 mean motion resonance at semimajor axis a≈130 au. Both objects are securely resonant on 10 Myr timescales, with one securely in the 9:1 resonance's leading asymmetric libration island and the other in either the symmetric or trailing asymmetric island. These two objects are the largest semimajor axis objects known with secure resonant classifications, and their detection in a carefully characterized survey allows for the first robust population estimate for a resonance beyond 100 au. The detection of these two objects implies a population in the 9:1 resonance of 1.1×104 objects with Hr<8.66 (D > 100 km) on similar orbits, with 95% confidence range of ∼0.4‑3×104. Integrations over 4 Gyr of an ensemble of clones chosen from within the orbit fit uncertainties for these objects reveal that they both have median resonance occupation timescales of ∼1 Gyr. These timescales are consistent with the hypothesis that these two objects originate in the scattering population but became transiently stuck to Neptune's 9:1 resonance within the last ∼1 Gyr of solar system evolution. Based on simulations of a model of the current scattering population, we estimate the expected resonance sticking population in the 9:1 resonance to be 1000--5000 objects with Hr<8.66 this is marginally consistent with the OSSOS 9:1 population estimate. We conclude that resonance sticking is a plausible explanation for the observed 9:1 population, but we also discuss the possibility of a primordial 9:1 population, which would have interesting implications for the Kuiper belt's dynamical history.

Utility of magnetic resonance imaging and nuclear magnetic resonance-based metabolomics for quantification of inflammatory lung injury

PubMed Central

Serkova, Natalie J.; Van Rheen, Zachary; Tobias, Meghan; Pitzer, Joshua E.; Wilkinson, J. Erby; Stringer, Kathleen A.

2008-01-01

Magnetic resonance imaging (MRI) and metabolic nuclear magnetic resonance (NMR) spectroscopy are clinically available but have had little application in the quantification of experimental lung injury. There is a growing and unfulfilled need for predictive animal models that can improve our understanding of disease pathogenesis and therapeutic intervention. Integration of MRI and NMR could extend the application of experimental data into the clinical setting. This study investigated the ability of MRI and metabolic NMR to detect and quantify inflammation-mediated lung injury. Pulmonary inflammation was induced in male B6C3F1 mice by intratracheal administration of IL-1β and TNF-α under isoflurane anesthesia. Mice underwent MRI at 2, 4, 6, and 24 h after dosing. At 6 and 24 h lungs were harvested for metabolic NMR analysis. Data acquired from IL-1β+TNF-α-treated animals were compared with saline-treated control mice. The hyperintense-to-total lung volume (HTLV) ratio derived from MRI was higher in IL-1β+TNF-α-treated mice compared with control at 2, 4, and 6 h but returned to control levels by 24 h. The ability of MRI to detect pulmonary inflammation was confirmed by the association between HTLV ratio and histological and pathological end points. Principal component analysis of NMR-detectable metabolites also showed a temporal pattern for which energy metabolism-based biomarkers were identified. These data demonstrate that both MRI and metabolic NMR have utility in the detection and quantification of inflammation-mediated lung injury. Integration of these clinically available techniques into experimental models of lung injury could improve the translation of basic science knowledge and information to the clinic. PMID:18441091

Broken symmetry dielectric resonators for high quality factor Fano metasurfaces

DOE PAGES

Campione, Salvatore; Liu, Sheng; Basilio, Lorena I.; ...

2016-10-25

We present a new approach to dielectric metasurface design that relies on a single resonator per unit cell and produces robust, high quality factor Fano resonances. Our approach utilizes symmetry breaking of highly symmetric resonator geometries, such as cubes, to induce couplings between the otherwise orthogonal resonator modes. In particular, we design perturbations that couple “bright” dipole modes to “dark” dipole modes whose radiative decay is suppressed by local field effects in the array. Our approach is widely scalable from the near-infrared to radio frequencies. We first unravel the Fano resonance behavior through numerical simulations of a germanium resonator-based metasurfacemore » that achieves a quality factor of ~1300 at ~10.8 μm. Then, we present two experimental demonstrations operating in the near-infrared (~1 μm): a silicon-based implementation that achieves a quality factor of ~350; and a gallium arsenide-based structure that achieves a quality factor of ~600, the highest near-infrared quality factor experimentally demonstrated to date with this kind of metasurface. Importantly, large electromagnetic field enhancements appear within the resonators at the Fano resonant frequencies. Here, we envision that combining high quality factor, high field enhancement resonances with nonlinear and active/gain materials such as gallium arsenide will lead to new classes of active optical devices.« less

Broken symmetry dielectric resonators for high quality factor Fano metasurfaces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Campione, Salvatore; Liu, Sheng; Basilio, Lorena I.

We present a new approach to dielectric metasurface design that relies on a single resonator per unit cell and produces robust, high quality factor Fano resonances. Our approach utilizes symmetry breaking of highly symmetric resonator geometries, such as cubes, to induce couplings between the otherwise orthogonal resonator modes. In particular, we design perturbations that couple “bright” dipole modes to “dark” dipole modes whose radiative decay is suppressed by local field effects in the array. Our approach is widely scalable from the near-infrared to radio frequencies. We first unravel the Fano resonance behavior through numerical simulations of a germanium resonator-based metasurfacemore » that achieves a quality factor of ~1300 at ~10.8 μm. Then, we present two experimental demonstrations operating in the near-infrared (~1 μm): a silicon-based implementation that achieves a quality factor of ~350; and a gallium arsenide-based structure that achieves a quality factor of ~600, the highest near-infrared quality factor experimentally demonstrated to date with this kind of metasurface. Importantly, large electromagnetic field enhancements appear within the resonators at the Fano resonant frequencies. Here, we envision that combining high quality factor, high field enhancement resonances with nonlinear and active/gain materials such as gallium arsenide will lead to new classes of active optical devices.« less

Surface impact on nanoparticle-based magnetic resonance imaging contrast agents

PubMed Central

Zhang, Weizhong; Liu, Lin; Chen, Hongmin; Hu, Kai; Delahunty, Ian; Gao, Shi; Xie, Jin

2018-01-01

Magnetic resonance imaging (MRI) is one of the most widely used diagnostic tools in the clinic. To improve imaging quality, MRI contrast agents, which can modulate local T1 and T2 relaxation times, are often injected prior to or during MRI scans. However, clinically used contrast agents, including Gd3+-based chelates and iron oxide nanoparticles (IONPs), afford mediocre contrast abilities. To address this issue, there has been extensive research on developing alternative MRI contrast agents with superior r1 and r2 relaxivities. These efforts are facilitated by the fast progress in nanotechnology, which allows for preparation of magnetic nanoparticles (NPs) with varied size, shape, crystallinity, and composition. Studies suggest that surface coatings can also largely affect T1 and T2 relaxations and can be tailored in favor of a high r1 or r2. However, the surface impact of NPs has been less emphasized. Herein, we review recent progress on developing NP-based T1 and T2 contrast agents, with a focus on the surface impact. PMID:29721097

Preoperative magnetic resonance imaging protocol for endoscopic cranial base image-guided surgery.

PubMed

Grindle, Christopher R; Curry, Joseph M; Kang, Melissa D; Evans, James J; Rosen, Marc R

2011-01-01

Despite the increasing utilization of image-guided surgery, no radiology protocols for obtaining magnetic resonance (MR) imaging of adequate quality are available in the current literature. At our institution, more than 300 endonasal cranial base procedures including pituitary, extended pituitary, and other anterior skullbase procedures have been performed in the past 3 years. To facilitate and optimize preoperative evaluation and assessment, there was a need to develop a magnetic resonance protocol. Retrospective Technical Assessment was performed. Through a collaborative effort between the otolaryngology, neurosurgery, and neuroradiology departments at our institution, a skull base MR image-guided (IGS) protocol was developed with several ends in mind. First, it was necessary to generate diagnostic images useful for the more frequently seen pathologies to improve work flow and limit the expense and inefficiency of case specific MR studies. Second, it was necessary to generate sequences useful for IGS, preferably using sequences that best highlight that lesion. Currently, at our institution, all MR images used for IGS are obtained using this protocol as part of preoperative planning. The protocol that has been developed allows for thin cut precontrast and postcontrast axial cuts that can be used to plan intraoperative image guidance. It also obtains a thin cut T2 axial series that can be compiled separately for intraoperative imaging, or may be fused with computed tomographic images for combined modality. The outlined protocol obtains image sequences effective for diagnostic and operative purposes for image-guided surgery using both T1 and T2 sequences. Copyright © 2011 Elsevier Inc. All rights reserved.

[A graph cuts-based interactive method for segmentation of magnetic resonance images of meningioma].

PubMed

Li, Shuan-qiang; Feng, Qian-jin; Chen, Wu-fan; Lin, Ya-zhong

2011-06-01

For accurate segmentation of the magnetic resonance (MR) images of meningioma, we propose a novel interactive segmentation method based on graph cuts. The high dimensional image features was extracted, and for each pixel, the probabilities of its origin, either the tumor or the background regions, were estimated by exploiting the weighted K-nearest neighborhood classifier. Based on these probabilities, a new energy function was proposed. Finally, a graph cut optimal framework was used for the solution of the energy function. The proposed method was evaluated by application in the segmentation of MR images of meningioma, and the results showed that the method significantly improved the segmentation accuracy compared with the gray level information-based graph cut method.

Optical micro resonance based sensor schemes for detection and identification of nano particles and biological agents in situ

NASA Astrophysics Data System (ADS)

Saetchnikov, Vladimir A.; Tcherniavskaia, Elina A.; Schweiger, Gustav; Ostendorf, Andreas

2010-05-01

A novel emerging technique for the label-free analysis of nano particles including biomolecules using optical micro cavity resonance is being developed. Various schemes based on a mechanically fixed microspheres as well as microspheres melted by laser on the tip of a standard single mode fiber have been investigated to make further development for microbial application. Water solutions of ethanol, HCl, glucose, vitamin C and biotin have been used to test refractive index changes by monitoring the magnitude of the whispering gallery modes spectral shift. Particular efforts were made for effective fixing of the micro spheres in the water flow, an optimal geometry for micro resonance observation and material of microsphere the most appropriate for microbial application. Optical resonance in free micro spheres from PMMA fixed in micro channels produced by photolithography has been observed under the laser power of less then 1 microwatt. Resonance shifts of C reactive protein water solutions as well as albumin solutions in pure water and with HCl modelling blood have been investigated. Introducing controlled amount of glass gel nano particles into sensor microsphere surrounding were accompanied by both correlative resonance shift (400 nm in diameter) and total reconstruct of resonance spectra (57 nm in diameter). Developed schemes have been demonstrated to be a promising technology platform for sensitive, lab-on-chip type sensor of diagnostic tools for different biological molecules, e.g. proteins, oligonucleotides, oligosaccharides, lipids, small molecules, viral particles, cells as well as in different experimental contexts e.g. proteomics, genomics, drug discovery, and membrane studies.

A MEMS-based high frequency x-ray chopper.

PubMed

Siria, A; Dhez, O; Schwartz, W; Torricelli, G; Comin, F; Chevrier, J

2009-04-29

Time-resolved x-ray experiments require intensity modulation at high frequencies (advanced rotating choppers have nowadays reached the kHz range). We here demonstrate that a silicon microlever oscillating at 13 kHz with nanometric amplitude can be used as a high frequency x-ray chopper. We claim that using micro-and nanoelectromechanical systems (MEMS and NEMS), it will be possible to achieve higher frequencies in excess of hundreds of megahertz. Working at such a frequency can open a wealth of possibilities in chemistry, biology and physics time-resolved experiments.

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

NASA Astrophysics Data System (ADS)

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

2013-12-01

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

Ultra-compact resonant tunneling-based TE-pass and TM-pass polarizers for SOI platform.

PubMed

Azzam, Shaimaa I; Obayya, Salah S A

2015-03-15

We investigate the polarization-dependent resonance tunneling effect in silicon waveguides to achieve ultra-compact and highly efficient polarization fitters for integrated silicon photonics, to the best of our knowledge for the first time. We hence propose simple structures for silicon-on-insulator transverse electric (TE)-pass and transverse magnetic (TM)-pass polarizers based on the resonance tunneling effect in silicon waveguides. The suggested TE-pass polarizer has insertion losses (IL), extinction ratio (ER), and return losses (RL) of 0.004 dB, 18 dB, and 24 dB, respectively; whereas, the TM-pass polarizer is characterized by IL, ER, and RL of 0.15 dB, 20 dB, and 23 dB, respectively. Both polarizers have an ultra-short device length of only 1.35 and 1.31 μm for the TE-pass and the TM-pass polarizers which are the shortest reported lengths to the best of our knowledge.

Viscous cavity damping of a microlever in a simple fluid.

PubMed

Siria, A; Drezet, A; Marchi, F; Comin, F; Huant, S; Chevrier, J

2009-06-26

We consider the problem of oscillation damping in air of a thermally actuated microlever as it gradually approaches an infinite wall in parallel geometry. As the gap is decreased from 20 microm down to 400 nm, we observe the increasing damping of the lever Brownian motion in the fluid laminar regime. This manifests itself as a linear decrease in the lever quality factor accompanied by a dramatic softening of its resonance, and eventually leads to the freezing of the CL oscillation. We are able to quantitatively explain this behavior by analytically solving the Navier-Stokes equation with perfect slip boundary conditions. Our findings may have implications for microfluidics and micro- and nanoelectromechanical applications.

Strain engineering of the silicon-vacancy center in diamond

NASA Astrophysics Data System (ADS)

Meesala, Srujan; Sohn, Young-Ik; Pingault, Benjamin; Shao, Linbo; Atikian, Haig A.; Holzgrafe, Jeffrey; Gündoǧan, Mustafa; Stavrakas, Camille; Sipahigil, Alp; Chia, Cleaven; Evans, Ruffin; Burek, Michael J.; Zhang, Mian; Wu, Lue; Pacheco, Jose L.; Abraham, John; Bielejec, Edward; Lukin, Mikhail D.; Atatüre, Mete; Lončar, Marko

2018-05-01

We control the electronic structure of the silicon-vacancy (SiV) color-center in diamond by changing its static strain environment with a nano-electro-mechanical system. This allows deterministic and local tuning of SiV optical and spin transition frequencies over a wide range, an essential step towards multiqubit networks. In the process, we infer the strain Hamiltonian of the SiV revealing large strain susceptibilities of order 1 PHz/strain for the electronic orbital states. We identify regimes where the spin-orbit interaction results in a large strain susceptibility of order 100 THz/strain for spin transitions, and propose an experiment where the SiV spin is strongly coupled to a nanomechanical resonator.

Design and implementation of optical switches based on nonlinear plasmonic ring resonators: Circular, square and octagon

NASA Astrophysics Data System (ADS)

Ghadrdan, Majid; Mansouri-Birjandi, Mohammad Ali

2018-05-01

In this paper, all-optical plasmonic switches (AOPS) based on various configurations of circular, square and octagon nonlinear plasmonic ring resonators (NPRR) were proposed and numerically investigated. Each of these configurations consisted of two metal-insulator-metal (MIM) waveguides coupled to each other by a ring resonator (RR). Nonlinear Kerr effect was used to show switching performance of the proposed NPRR. The result showed that the octagon switch structure had lower threshold power and higher transmission ratio than square and circular switch structures. The octagon switch structure had a low threshold power equal to 7.77 MW/cm2 and the high transmission ratio of approximately 0.6. Therefore, the octagon switch structure was an appropriate candidate to be applied in optical integration circuits as an AOPS.

Photonic crystal ring resonator based optical filters for photonic integrated circuits

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robinson, S., E-mail: mail2robinson@gmail.com

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

GaAs-based resonant tunneling diode (RTD) epitaxy on Si for highly sensitive strain gauge applications.

PubMed

Li, Jie; Guo, Hao; Liu, Jun; Tang, Jun; Ni, Haiqiao; Shi, Yunbo; Xue, Chenyang; Niu, Zhichuan; Zhang, Wendong; Li, Mifeng; Yu, Ying

2013-05-08

As a highly sensitive strain gauge element, GaAs-based resonant tunneling diode (RTD) has already been applied in microelectromechanical system (MEMS) sensors. Due to poor mechanical properties and high cost, GaAs-based material has been limited in applications as the substrate for MEMS. In this work, we present a method to fabricate the GaAs-based RTD on Si substrate. From the experimental results, it can be concluded that the piezoresistive coefficient achieved with this method reached 3.42 × 10-9 m2/N, which is about an order of magnitude higher than the Si-based semiconductor piezoresistors.

CMOS compatible thin-film ALD tungsten nanoelectromechanical devices

NASA Astrophysics Data System (ADS)

Davidson, Bradley Darren

This research focuses on the development of a novel, low-temperature, CMOS compatible, atomic-layer-deposition (ALD) enabled NEMS fabrication process for the development of ALD Tungsten (WALD) NEMS devices. The devices are intended for use in CMOS/NEMS hybrid systems, and NEMS based micro-processors/controllers capable of reliable operation in harsh environments not accessible to standard CMOS technologies. The majority of NEMS switches/devices to date have been based on carbon-nano-tube (CNT) designs. The devices consume little power during actuation, and as expected, have demonstrated actuation voltages much smaller than MEMS switches. Unfortunately, NEMS CNT switches are not typically CMOS integrable due to the high temperatures required for their growth, and their fabrication typically results in extremely low and unpredictable yields. Thin-film NEMS devices offer great advantages over reported CNT devices for several reasons, including: higher fabrication yields, low-temperature (CMOS compatible) deposition techniques like ALD, and increased control over design parameters/device performance metrics, i.e., device geometry. Furthermore, top-down, thin-film, nano-fabrication techniques are better capable of producing complicated device geometries than CNT based processes, enabling the design and development of multi-terminal switches well-suited for low-power hybrid NEMS/CMOS systems as well as electromechanical transistors and logic devices for use in temperature/radiation hard computing architectures. In this work several novel, low-temperature, CMOS compatible fabrication technologies, employing WALD as a structural layer for MEMS or NEMS devices, were developed. The technologies developed are top-down nano-scale fabrication processes based on traditional micro-machining techniques commonly used in the fabrication of MEMS devices. Using these processes a variety of novel WALD NEMS devices have been successfully fabricated and characterized. Using two different

Magnetic field detection using magnetorheological optical resonators

NASA Astrophysics Data System (ADS)

Rubino, Edoardo; Ioppolo, Tindaro

2018-02-01

In this paper, we investigate the feasibility of a magnetic field sensor that is based on a magnetorheological micro-optical resonator. The optical resonator has a spherical shape and a diameter of a few hundred micrometers. The resonator is fabricated by using a polymeric matrix made of polyvinyl chloride (PVC) plastisol with embedded magnetically polarizable micro-particles. When the optical resonator is subjected to an external magnetic field, the morphology (radius and refractive index) of the resonator is perturbed by the magnetic forces acting on it, leading to a shift of the optical resonances also known as whispering gallery modes (WGM). In this study, the effect of a static and harmonic magnetic field, as well as the concentration of the magnetic micro-particles on the optical mode shift is investigated. The optical resonances obtained with the PVC plastisol resonator showed a quality factor of 106 . The dynamical behavior of the optical resonator is investigated in the range between 0 and 200 Hz. The sensitivity of the optical resonator reaches a maximum value for a ratio between micro-particles and the polymeric matrix of 2:1 in weight. Experimental results indicate a sensitivity of 0.297 pm/mT leading to a resolution of 336 μT.

Photonic crystal resonances for sensing and imaging

NASA Astrophysics Data System (ADS)

Pitruzzello, Giampaolo; Krauss, Thomas F.

2018-07-01

This review provides an insight into the recent developments of photonic crystal (PhC)-based devices for sensing and imaging, with a particular emphasis on biosensors. We focus on two main classes of devices, namely sensors based on PhC cavities and those on guided mode resonances (GMRs). This distinction is able to capture the richness of possibilities that PhCs are able to offer in this space. We present recent examples highlighting applications where PhCs can offer new capabilities, open up new applications or enable improved performance, with a clear emphasis on the different types of structures and photonic functions. We provide a critical comparison between cavity-based devices and GMR devices by highlighting strengths and weaknesses. We also compare PhC technologies and their sensing mechanism to surface plasmon resonance, microring resonators and integrated interferometric sensors.

Ultracompact electro-optic phase modulator based on III-V-on-silicon microdisk resonator.

PubMed

Lloret, J; Kumar, R; Sales, S; Ramos, F; Morthier, G; Mechet, P; Spuesens, T; Van Thourhout, D; Olivier, N; Fédéli, J-M; Capmany, J

2012-06-15

A novel ultracompact electro-optic phase modulator based on a single 9 μm-diameter III-V microdisk resonator heterogeneously integrated on and coupled to a nanophotonic waveguide is presented. Modulation is enabled by effective index modification through carrier injection. Proof-of-concept implementation involving binary phase shift keying modulation format is assembled. A power imbalance of ∼0.6  dB between both symbols and a modulation rate up to 1.8 Gbps are demonstrated without using any special driving technique.

Gallium arsenide based surface plasmon resonance for glucose monitoring

NASA Astrophysics Data System (ADS)

Patil, Harshada; Sane, Vani; Sriram, G.; Indumathi, T. S; Sharan, Preeta

2015-07-01

The recent trends in the semiconductor and microwave industries has enabled the development of scalable microfabrication technology which produces a superior set of performance as against its counterparts. Surface Plasmon Resonance (SPR) based biosensors are a special class of optical sensors that become affected by electromagnetic waves. It is found that bio-molecular recognition element immobilized on the SPR sensor surface layer reveals a characteristic interaction with various sample solutions during the passage of light. The present work revolves around developing painless glucose monitoring systems using fluids containing glucose like saliva, urine, sweat or tears instead of blood samples. Non-invasive glucose monitoring has long been simulated using label free detection mechanisms and the same concept is adapted. In label-free detection, target molecules are not labeled or altered, and are detected in their natural forms. Label-free detection mechanisms involves the measurement of refractive index (RI) change induced by molecular interactions. These interactions relates the sample concentration or surface density, instead of total sample mass. After simulation it has been observed that the result obtained is highly accurate and sensitive. The structure used here is SPR sensor based on channel waveguide. The tools used for simulation are RSOFT FULLWAVE, MEEP and MATLAB etc.

Wide wavelength range tunable one-dimensional silicon nitride nano-grating guided mode resonance filter based on azimuthal rotation

NASA Astrophysics Data System (ADS)

Yukino, Ryoji; Sahoo, Pankaj K.; Sharma, Jaiyam; Takamura, Tsukasa; Joseph, Joby; Sandhu, Adarsh

2017-01-01

We describe wavelength tuning in a one dimensional (1D) silicon nitride nano-grating guided mode resonance (GMR) structure under conical mounting configuration of the device. When the GMR structure is rotated about the axis perpendicular to the surface of the device (azimuthal rotation) for light incident at oblique angles, the conditions for resonance are different than for conventional GMR structures under classical mounting. These resonance conditions enable tuning of the GMR peak position over a wide range of wavelengths. We experimental demonstrate tuning over a range of 375 nm between 500 nm˜875 nm. We present a theoretical model to explain the resonance conditions observed in our experiments and predict the peak positions with show excellent agreement with experiments. Our method for tuning wavelengths is simpler and more efficient than conventional procedures that employ variations in the design parameters of structures or conical mounting of two-dimensional (2D) GMR structures and enables a single 1D GMR device to function as a high efficiency wavelength filter over a wide range of wavelengths. We expect tunable filters based on this technique to be applicable in a wide range of fields including astronomy and biomedical imaging.

Tunable filters based on an SOI nano-wire waveguide micro ring resonator

NASA Astrophysics Data System (ADS)

Shuai, Li; Yuanda, Wu; Xiaojie, Yin; Junming, An; Jianguang, Li; Hongjie, Wang; Xiongwei, Hu

2011-08-01

Micro ring resonator (MRR) filters based on a silicon on insulator (SOI) nanowire waveguide are fabricated by electron beam photolithography (EBL) and inductive coupled plasma (ICP) etching technology. The cross-section size of the strip waveguides is 450 × 220 nm2, and the bending radius of the micro ring is around 5 μm. The test results from the tunable filter based on a single ring show that the free spectral range (FSR) is 16.8 nm and the extinction ratio (ER) around the wavelength 1550 nm is 18.1 dB. After thermal tuning, the filter's tuning bandwidth reaches 4.8 nm with a tuning efficiency of 0.12 nm/°C Meanwhile, we fabricated and studied multi-channel filters based on a single ring and a double ring. After measurement, we drew the following conclusions: during the signal transmission of multi-channel filters, crosstalk exists mainly among different transmission channels and are fairly distinct when there are signals input to add ports.

Application of RF-MEMS-Based Split Ring Resonators (SRRs) to the Implementation of Reconfigurable Stopband Filters: A Review

PubMed Central

Martín, Ferran; Bonache, Jordi

2014-01-01

In this review paper, several strategies for the implementation of reconfigurable split ring resonators (SRRs) based on RF-MEMS switches are presented. Essentially three types of RF-MEMS combined with split rings are considered: (i) bridge-type RF-MEMS on top of complementary split ring resonators CSRRs; (ii) cantilever-type RF-MEMS on top of SRRs; and (iii) cantilever-type RF-MEMS integrated with SRRs (or RF-MEMS SRRs). Advantages and limitations of these different configurations from the point of view of their potential applications for reconfigurable stopband filter design are discussed, and several prototype devices are presented. PMID:25474378

Field resonance propulsion concept

NASA Technical Reports Server (NTRS)

Holt, A. C.

1979-01-01

A propulsion concept was developed based on a proposed resonance between coherent, pulsed electromagnetic wave forms, and gravitational wave forms (or space-time metrics). Using this concept a spacecraft propulsion system potentially capable of galactic and intergalactic travel without prohibitive travel times was designed. The propulsion system utilizes recent research associated with magnetic field line merging, hydromagnetic wave effects, free-electron lasers, laser generation of megagauss fields, and special structural and containment metals. The research required to determine potential, field resonance characteristics and to evaluate various aspects of the spacecraft propulsion design is described.

Locally resonant sonic materials

PubMed

Liu; Zhang; Mao; Zhu; Yang; Chan; Sheng

2000-09-08

We have fabricated sonic crystals, based on the idea of localized resonant structures, that exhibit spectral gaps with a lattice constant two orders of magnitude smaller than the relevant wavelength. Disordered composites made from such localized resonant structures behave as a material with effective negative elastic constants and a total wave reflector within certain tunable sonic frequency ranges. A 2-centimeter slab of this composite material is shown to break the conventional mass-density law of sound transmission by one or more orders of magnitude at 400 hertz.

Resonant power processors. II - Methods of control

NASA Technical Reports Server (NTRS)

Oruganti, R.; Lee, F. C.

1984-01-01

The nature of resonant converter control is discussed. Employing the state-portrait, different control methods for series resonant converter are identified and their performance evaluated based on their stability, response to control and load changes and range of operation. A new control method, optimal-trajectory control, is proposed which, by utilizing the state trajectories as control laws, continuously monitors the energy level of the resonant tank. The method is shown to have superior control properties especially under transient operation.

Highly sensitive current sensor based on an optical microfiber loop resonator incorporating low index polymer

NASA Astrophysics Data System (ADS)

Yoon, Min-Seok; Han, Young-Geun

2014-05-01

A highly sensitive current sensor based on an optical microfiber loop resonator (MLR) incorporating low index polymer is proposed and experimentally demonstrated. The microfiber with a waist diameter of 1 μm is wrapped around the nicrhrome wire with low index polymer coating and the optical MLR is realized. The use of the microfiber and low index polymer with high thermal property can effectively improve the current sensitivity of the proposed MLR-based sensing probe to be 437.9 pm/A2, which is ~10 times higher than the previous result.

Polymer based resonant waveguide grating photonic filter with on-chip thermal tuning

NASA Astrophysics Data System (ADS)

Chaudhuri, Ritesh Ray; Enemuo, Amarachukwu N.; Song, Youngsik; Seo, Sang-Woo

2018-07-01

In this paper, we present the development of a multilayer polymer resonant waveguide grating (RWG)-based optical filter with an integrated microheater for on-chip thermal spectral tuning. RWG optical filter is fabricated using polymer-based materials. Therefore, its integration can be applied to different material platforms. Typical RWG structure is sensitive to back optical reflection from the structures below. To reduce the effect of back reflection from the metal heater and improve the quality of the integrated RWG filter output, an intermediate absorption layer was implemented utilizing an epoxy based carbon coating. This approach effectively suppresses the background noise in the RWG characteristics. The central wavelength of the reported filter was designed around 1550 nm. Experimentally, wavelength tuning of 21.96 nm was achieved for operating temperature range of 81 °C with approximately 150mW power consumption. Based on the layer-by-layer fabrication approach, the presented thermally tunable RWG filter on a chip has potential for use in low cost hybrid communication systems and spectral sensing applications.

Surface plasmon resonance based fiber optic detection of chlorine utilizing polyvinylpyrolidone supported zinc oxide thin films.

PubMed

Tabassum, Rana; Gupta, Banshi D

2015-03-21

A highly sensitive chlorine sensor for an aqueous medium is fabricated using an optical fiber surface plasmon resonance (OFSPR) system. An OFSPR-based chlorine sensor is designed with a multilayer-type platform by zinc oxide (ZnO) and polyvinylpyrollidone (PVP) film morphology manipulations. Among all the methodologies of transduction reported in the field of solid state chemical and biochemical sensing, our attention is focused on the Kretschmann configuration optical fiber sensing technique using the mechanism of surface plasmon resonance. The optical fiber surface plasmon resonance (SPR) chlorine sensor is developed using a multimode optical fiber with the PVP-supported ZnO film deposited over a silver-coated unclad core of the fiber. A spectral interrogation mode of operation is used to characterize the sensor. In an Ag/ZnO/PVP multilayer system, the absorption of chlorine in the vicinity of the sensing region is performed by the PVP layer and the zinc oxide layer enhances the shift in resonance wavelength. It is, experimentally, demonstrated that the SPR wavelength shifts nonlinearly towards the red side of the visible region with an increase in the chlorine concentration in an aqueous medium while the sensitivity of the sensor decreases linearly with an increase in the chlorine concentration. As the proposed sensor utilizes an optical fiber, it possesses the additional advantages of fiber such as less signal degradation, less susceptibility to electromagnetic interference, possibility of remote sensing, probe miniaturization, probe re-usability, online monitoring, small size, light weight and low cost.

Optical resonators and neural networks

NASA Astrophysics Data System (ADS)

Anderson, Dana Z.

1986-08-01

It may be possible to implement neural network models using continuous field optical architectures. These devices offer the inherent parallelism of propagating waves and an information density in principle dictated by the wavelength of light and the quality of the bulk optical elements. Few components are needed to construct a relatively large equivalent network. Various associative memories based on optical resonators have been demonstrated in the literature, a ring resonator design is discussed in detail here. Information is stored in a holographic medium and recalled through a competitive processes in the gain medium supplying energy to the ring rsonator. The resonator memory is the first realized example of a neural network function implemented with this kind of architecture.

Resonance of magnetization excited by voltage in magnetoelectric heterostructures

NASA Astrophysics Data System (ADS)

Yu, Guoliang; Zhang, Huaiwu; Li, Yuanxun; Li, Jie; Zhang, Dainan; Sun, Nian

2018-04-01

Manipulation of magnetization dynamics is critical for spin-based devices. Voltage driven magnetization resonance is promising for realizing low-power information processing systems. Here, we show through Finite Element Method (FEM) simulations that magnetization resonance in nanoscale magnetic elements can be generated by a radio frequency (rf) voltage via the converse magnetoelectric (ME) effect. The magnetization dynamics induced by voltage in a ME heterostructures is simulated by taking into account the magnetoelastic and piezoelectric coupling mechanisms among magnetization, strain and voltage. The frequency of the excited magnetization resonance is equal to the driving rf voltage frequency. The proposed voltage driven magnetization resonance excitation mechanism opens a way toward energy-efficient spin based device applications.

Photonic crystal ring resonator-based four-channel dense wavelength division multiplexing demultiplexer on silicon on insulator platform: design and analysis

NASA Astrophysics Data System (ADS)

Sreenivasulu, Tupakula; Bhowmick, Kaustav; Samad, Shafeek A.; Yadunath, Thamerassery Illam R.; Badrinarayana, Tarimala; Hegde, Gopalkrishna; Srinivas, Talabattula

2018-04-01

A micro/nanofabrication feasible compact photonic crystal (PC) ring-resonator-based channel drop filter has been designed and analyzed for operation in C and L bands of communication window. The four-channel demultiplexer consists of ring resonators of holes in two-dimensional PC slab. The proposed assembly design of dense wavelength division multiplexing setup is shown to achieve optimal quality factor, without altering the lattice parameters or resonator size or inclusion of scattering holes. Transmission characteristics are analyzed using the three-dimensional finite-difference time-domain simulation approach. The radiation loss of the ring resonator was minimized by forced cancelation of radiation fields by fine-tuning the air holes inside the ring resonator. An average cross talk of -34 dB has been achieved between the adjacent channels maintaining an average quality factor of 5000. Demultiplexing is achieved by engineering only the air holes inside the ring, which makes it a simple and tolerant design from the fabrication perspective. Also, the device footprint of 500 μm2 on silicon on insulator platform makes it easy to fabricate the device using e-beam lithography technique.

Protein-based flexible whispering gallery mode resonators

NASA Astrophysics Data System (ADS)

Yilmaz, Huzeyfe; Pena-Francesch, Abdon; Xu, Linhua; Shreiner, Robert; Jung, Huihun; Huang, Steven H.; Özdemir, Sahin K.; Demirel, Melik C.; Yang, Lan

2016-02-01

The idea of creating photonics tools for sensing, imaging and material characterization has long been pursued and many achievements have been made. Approaching the level of solutions provided by nature however is hindered by routine choice of materials. To this end recent years have witnessed a great effort to engineer mechanically flexible photonic devices using polymer substrates. On the other hand, biodegradability and biocompatibility still remains to be incorporated. Hence biomimetics holds the key to overcome the limitations of traditional materials in photonics design. Natural proteins such as sucker ring teeth (SRT) and silk for instance have remarkable mechanical and optical properties that exceed the endeavors of most synthetic and natural polymers. Here we demonstrate for the first time, toroidal whispering gallery mode resonators (WGMR) fabricated entirely from protein structures such as SRT of Loligo vulgaris (European squid) and silk from Bombyx mori. We provide here complete optical and material characterization of proteinaceous WGMRs, revealing high quality factors in microscale and enhancement of Raman signatures by a microcavity. We also present a most simple application of a WGMR as a natural protein add-drop filter, made of SRT protein. Our work shows that with protein-based materials, optical, mechanical and thermal properties can be devised at the molecular level and it lays the groundwork for future eco-friendly, flexible photonics device design.

Theoretical study of surface plasmon resonance sensors based on 2D bimetallic alloy grating

NASA Astrophysics Data System (ADS)

Dhibi, Abdelhak; Khemiri, Mehdi; Oumezzine, Mohamed

2016-11-01

A surface plasmon resonance (SPR) sensor based on 2D alloy grating with a high performance is proposed. The grating consists of homogeneous alloys of formula MxAg1-x, where M is gold, copper, platinum and palladium. Compared to the SPR sensors based a pure metal, the sensor based on angular interrogation with silver exhibits a sharper (i.e. larger depth-to-width ratio) reflectivity dip, which provides a big detection accuracy, whereas the sensor based on gold exhibits the broadest dips and the highest sensitivity. The detection accuracy of SPR sensor based a metal alloy is enhanced by the increase of silver composition. In addition, the composition of silver which is around 0.8 improves the sensitivity and the quality of SPR sensor of pure metal. Numerical simulations based on rigorous coupled wave analysis (RCWA) show that the sensor based on a metal alloy not only has a high sensitivity and a high detection accuracy, but also exhibits a good linearity and a good quality.

Tunable Micro- and Nanomechanical Resonators

PubMed Central

Zhang, Wen-Ming; Hu, Kai-Ming; Peng, Zhi-Ke; Meng, Guang

2015-01-01

Advances in micro- and nanofabrication technologies have enabled the development of novel micro- and nanomechanical resonators which have attracted significant attention due to their fascinating physical properties and growing potential applications. In this review, we have presented a brief overview of the resonance behavior and frequency tuning principles by varying either the mass or the stiffness of resonators. The progress in micro- and nanomechanical resonators using the tuning electrode, tuning fork, and suspended channel structures and made of graphene have been reviewed. We have also highlighted some major influencing factors such as large-amplitude effect, surface effect and fluid effect on the performances of resonators. More specifically, we have addressed the effects of axial stress/strain, residual surface stress and adsorption-induced surface stress on the sensing and detection applications and discussed the current challenges. We have significantly focused on the active and passive frequency tuning methods and techniques for micro- and nanomechanical resonator applications. On one hand, we have comprehensively evaluated the advantages and disadvantages of each strategy, including active methods such as electrothermal, electrostatic, piezoelectrical, dielectric, magnetomotive, photothermal, mode-coupling as well as tension-based tuning mechanisms, and passive techniques such as post-fabrication and post-packaging tuning processes. On the other hand, the tuning capability and challenges to integrate reliable and customizable frequency tuning methods have been addressed. We have additionally concluded with a discussion of important future directions for further tunable micro- and nanomechanical resonators. PMID:26501294

An ENG resonator-based microwave sensor for the characterization of aqueous glucose

NASA Astrophysics Data System (ADS)

Kumari, Ratnesh; Patel, Piyush N.; Yadav, Rahul

2018-02-01

This work proposes a microwave filter with a notched frequency of transmission using an epsilon negative (ENG) unit-cell resonator as a sensor device. The device finds important application for the characterization of life-saving samples such as glucose. The ENG structure consists of two complementary geometries in the shape of ring and horn. The structure efficiently inhibits the incoming RF signal and creates a stopband resonance at 2.074 GHz. The printed circuit board of the layout was realized using FR-4 substrate of relative permittivity ɛ r  =  4.4, and height of 1.6 mm. It is experimentally seen that in the complementary area of horn and circular ring, the glucose sample perturbs the air-dielectric fringing fields which exist over the complementary area and modifies the frequency of stopband resonance. A change in sensor resonance was recorded and calibrated for different concentrations of glucose sample. The sensor exhibits a linear response for glucose concentration ranging from 20 to 100 mg ml-1 in the sensing area.

Tunable Magnetic Resonance in Microwave Spintronics Devices

NASA Technical Reports Server (NTRS)

Chen, Yunpeng; Fan, Xin; Xie, Yunsong; Zhou, Yang; Wang, Tao; Wilson, Jeffrey D.; Simons, Rainee N.; Chui, Sui-Tat; Xiao, John Q.

2015-01-01

Magnetic resonance is one of the key properties of magnetic materials for the application of microwave spintronics devices. The conventional method for tuning magnetic resonance is to use an electromagnet, which provides very limited tuning range. Hence, the quest for enhancing the magnetic resonance tuning range without using an electromagnet has attracted tremendous attention. In this paper, we exploit the huge exchange coupling field between magnetic interlayers, which is on the order of 4000 Oe and also the high frequency modes of coupled oscillators to enhance the tuning range. Furthermore, we demonstrate a new scheme to control the magnetic resonance frequency. Moreover, we report a shift in the magnetic resonance frequency as high as 20 GHz in CoFe based tunable microwave spintronics devices, which is 10X higher than conventional methods.

Tunable Magnetic Resonance in Microwave Spintronics Devices

NASA Technical Reports Server (NTRS)

Chen, Yunpeng; Fan, Xin; Xie, Yungsong; Zhou, Yang; Wang, Tao; Wilson, Jeffrey D.; Simons, Rainee N.; Chui, Sui-Tat; Xiao, John Q.

2015-01-01

Magnetic resonance is one of the key properties of magnetic materials for the application of microwave spintronics devices. The conventional method for tuning magnetic resonance is to use an electromagnet, which provides very limited tuning range. Hence, the quest for enhancing the magnetic resonance tuning range without using an electromagnet has attracted tremendous attention. In this paper, we exploit the huge exchange coupling field between magnetic interlayers, which is on the order of 4000 Oe and also the high frequency modes of coupled oscillators to enhance the tuning range. Furthermore, we demonstrate a new scheme to control the magnetic resonance frequency. Moreover, we report a shift in the magnetic resonance frequency as high as 20 GHz in CoFe-based tunable microwave spintronics devices, which is 10X higher than conventional methods.

Metamaterial Combining Electric- and Magnetic-Dipole-Based Configurations for Unique Dual-Band Signal Enhancement in Ultrahigh-Field Magnetic Resonance Imaging

PubMed Central

2017-01-01

Magnetic resonance imaging and spectroscopy (MRI and MRS) are both widely used techniques in medical diagnostics and research. One of the major thrusts in recent years has been the introduction of ultrahigh-field magnets in order to boost the sensitivity. Several MRI studies have examined further potential improvements in sensitivity using metamaterials, focusing on single frequency applications. However, metamaterials have yet to reach a level that is practical for routine MRI use. In this work, we explore a new metamaterial implementation for MRI, a dual-nuclei resonant structure, which can be used for both proton and heteronuclear magnetic resonance. Our approach combines two configurations, one based on a set of electric dipoles for the low frequency band, and the second based on a set of magnetic dipoles for the high frequency band. We focus on the implementation of a dual-nuclei metamaterial for phosphorus and proton imaging and spectroscopy at an ultrahigh-field strength of 7 T. In vivo scans using this flexible and compact structure show that it locally enhances both the phosphorus and proton transmit and receive sensitivities. PMID:28901137

Metamaterial Combining Electric- and Magnetic-Dipole-Based Configurations for Unique Dual-Band Signal Enhancement in Ultrahigh-Field Magnetic Resonance Imaging.

PubMed

Schmidt, Rita; Webb, Andrew

2017-10-11

Magnetic resonance imaging and spectroscopy (MRI and MRS) are both widely used techniques in medical diagnostics and research. One of the major thrusts in recent years has been the introduction of ultrahigh-field magnets in order to boost the sensitivity. Several MRI studies have examined further potential improvements in sensitivity using metamaterials, focusing on single frequency applications. However, metamaterials have yet to reach a level that is practical for routine MRI use. In this work, we explore a new metamaterial implementation for MRI, a dual-nuclei resonant structure, which can be used for both proton and heteronuclear magnetic resonance. Our approach combines two configurations, one based on a set of electric dipoles for the low frequency band, and the second based on a set of magnetic dipoles for the high frequency band. We focus on the implementation of a dual-nuclei metamaterial for phosphorus and proton imaging and spectroscopy at an ultrahigh-field strength of 7 T. In vivo scans using this flexible and compact structure show that it locally enhances both the phosphorus and proton transmit and receive sensitivities.

[Magnetic resonance compatibility research for coronary mental stents].

PubMed

Wang, Ying; Liu, Li; Wang, Shuo; Shang, Ruyao; Wang, Chunren

2015-01-01

The objective of this article is to research magnetic resonance compatibility for coronary mental stents, and to evaluate the magnetic resonance compatibility based on laboratory testing results. Coronary stents magnetic resonance compatibility test includes magnetically induced displacement force test, magnetically induced torque test, radio frequency induced heating and evaluation of MR image. By magnetic displacement force and torque values, temperature, and image distortion values to determine metal coronary stent demagnetization effect. The methods can be applied to test magnetic resonance compatibility for coronary mental stents and evaluate its demagnetization effect.

Detection of network attacks based on adaptive resonance theory

NASA Astrophysics Data System (ADS)

Bukhanov, D. G.; Polyakov, V. M.

2018-05-01

The paper considers an approach to intrusion detection systems using a neural network of adaptive resonant theory. It suggests the structure of an intrusion detection system consisting of two types of program modules. The first module manages connections of user applications by preventing the undesirable ones. The second analyzes the incoming network traffic parameters to check potential network attacks. After attack detection, it notifies the required stations using a secure transmission channel. The paper describes the experiment on the detection and recognition of network attacks using the test selection. It also compares the obtained results with similar experiments carried out by other authors. It gives findings and conclusions on the sufficiency of the proposed approach. The obtained information confirms the sufficiency of applying the neural networks of adaptive resonant theory to analyze network traffic within the intrusion detection system.

Miniature Sapphire Acoustic Resonator - MSAR

NASA Technical Reports Server (NTRS)

Wang, Rabi T.; Tjoelker, Robert L.

2011-01-01

A room temperature sapphire acoustics resonator incorporated into an oscillator represents a possible opportunity to improve on quartz ultrastable oscillator (USO) performance, which has been a staple for NASA missions since the inception of spaceflight. Where quartz technology is very mature and shows a performance improvement of perhaps 1 dB/decade, these sapphire acoustic resonators when integrated with matured quartz electronics could achieve a frequency stability improvement of 10 dB or more. As quartz oscillators are an essential element of nearly all types of frequency standards and reference systems, the success of MSAR would advance the development of frequency standards and systems for both groundbased and flight-based projects. Current quartz oscillator technology is limited by quartz mechanical Q. With a possible improvement of more than x 10 Q with sapphire acoustic modes, the stability limit of current quartz oscillators may be improved tenfold, to 10(exp -14) at 1 second. The electromagnetic modes of sapphire that were previously developed at JPL require cryogenic temperatures to achieve the high Q levels needed to achieve this stability level. However sapphire fs acoustic modes, which have not been used before in a high-stability oscillator, indicate the required Q values (as high as Q = 10(exp 8)) may be achieved at room temperature in the kHz range. Even though sapphire is not piezoelectric, such a high Q should allow electrostatic excitation of the acoustic modes with a combination of DC and AC voltages across a small sapphire disk (approximately equal to l mm thick). The first evaluations under this task will test predictions of an estimated input impedance of 10 kilohms at Q = 10(exp 8), and explore the Q values that can be realized in a smaller resonator, which has not been previously tested for acoustic modes. This initial Q measurement and excitation demonstration can be viewed similar to a transducer converting electrical energy to

A Balanced Tri-band PD Based on Microstrip-slotline Transition Structure Embedded Complementary Split-ring Resonators

NASA Astrophysics Data System (ADS)

Chen, Lei; Li, Xiao Yan; Wei, Feng

2017-12-01

A balanced tri-band equal power divider (PD) is proposed based on a balanced stepped-impedance microstrip-slotline transition structure in this paper. Multi-band differential-mode (DM) responses can be realized by embedding multiple complementary split-ring resonators (CSRRs) into the slotline resonator. It is found that a high and wideband common-mode (CM) suppression can be achieved. Moreover, the center frequencies of the DM passbands are independent from the CM ones, which significantly simplifies the design procedure. In order to validate its practicalbility, a balanced PD with three DM passbands centred at 1.57, 2.5 and 3.5 GHz is fabricated and a good agreement between the simulated and measured results is observed. To our best knowledge, a balanced tri-band PD is the first ever reported.

Labyrinth double split open loop resonator based bandpass filter design for S, C and X-band application

NASA Astrophysics Data System (ADS)

Alam, Jubaer; Faruque, Mohammad Rashed Iqbal; Tariqul Islam, Mohammad

2018-07-01

Nested circular shaped Labyrinth double split open loop resonators (OLRs) are introduced in this article to design a triple bandpass filter for 3.01 GHz, 7.39 GHz and 12.88 GHz applications. A Rogers RT-5880 is used as a substrate to design the proposed passband filter which has a succinct structure where the attainment of the resonator is explored both integrally and experimentally. The same structure is designed on both sides of the substrate and an analysis is made on the current distribution. Based on the proposed resonator, a bandpass filter is designed and fabricated to justify the perception focusing on 3.01 GHz, 7.39 GHz and 12.88 GHz. It has also been observed by the Nicolson–Ross–Weir approach at the filtering frequencies. The effective electromagnetic parameters retrieved from the simulation of the S-parameters imply that the OLR metamaterial filter shows negative refraction bands. Having an auspicious design and double negative characteristics, this structure is suitable for triple passband filters, particularly for S, C and X-band applications.

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

PubMed

Wang, Tianyang; Chu, Fulei; Han, Qinkai

2017-03-01

Identifying the differences between the spectra or envelope spectra of a faulty signal and a healthy baseline signal is an efficient planetary gearbox local fault detection strategy. However, causes other than local faults can also generate the characteristic frequency of a ring gear fault; this may further affect the detection of a local fault. To address this issue, a new filtering algorithm based on the meshing resonance phenomenon is proposed. In detail, the raw signal is first decomposed into different frequency bands and levels. Then, a new meshing index and an MRgram are constructed to determine which bands belong to the meshing resonance frequency band. Furthermore, an optimal filter band is selected from this MRgram. Finally, the ring gear fault can be detected according to the envelope spectrum of the band-pass filtering result. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

GaAs-based resonant tunneling diode (RTD) epitaxy on Si for highly sensitive strain gauge applications

PubMed Central

2013-01-01

As a highly sensitive strain gauge element, GaAs-based resonant tunneling diode (RTD) has already been applied in microelectromechanical system (MEMS) sensors. Due to poor mechanical properties and high cost, GaAs-based material has been limited in applications as the substrate for MEMS. In this work, we present a method to fabricate the GaAs-based RTD on Si substrate. From the experimental results, it can be concluded that the piezoresistive coefficient achieved with this method reached 3.42 × 10−9 m2/N, which is about an order of magnitude higher than the Si-based semiconductor piezoresistors. PMID:23651496

UWB Bandpass Filter with Ultra-wide Stopband based on Ring Resonator

NASA Astrophysics Data System (ADS)

Kazemi, Maryam; Lotfi, Saeedeh; Siahkamari, Hesam; Mohammadpanah, Mahmood

2018-04-01

An ultra-wideband (UWB) bandpass filter with ultra-wide stopband based on a rectangular ring resonator is presented. The filter is designed for the operational frequency band from 4.10 GHz to 10.80 GHz with an ultra-wide stopband from 11.23 GHz to 40 GHz. The even and odd equivalent circuits are used to achieve a suitable analysis of the proposed filter performance. To verify the design and analysis, the proposed bandpass filter is simulated using full-wave EM simulator Advanced Design System and fabricated on a 20mil thick Rogers_RO4003 substrate with relative permittivity of 3.38 and a loss tangent of 0.0021. The proposed filter behavior is investigated and simulation results are in good agreement with measurement results.

Sensing analysis based on tunable Fano resonance in terahertz graphene-layered metamaterials

NASA Astrophysics Data System (ADS)

Xu, Hui; Zhao, Mingzhuo; Chen, Zhiquan; Zheng, Mingfei; Xiong, Cuixiu; Zhang, Baihui; Li, Hongjian

2018-05-01

We theoretically investigate the sensing characteristics based on tunable Fano resonance in terahertz graphene-layered metamaterials. A Fano phenomenon comes from destructive interference in a narrow frequency range, and it can lead to a high figure of merit of ˜9786. A simple model for sensitivity is presented, and the sensitivity can reach up to 7885 nm/RIU. Besides, the Fano peak becomes more and more unobvious as symmetry breaking slowly recovers. We use an appropriate theoretical theory to explain the generation of Fano phenomena. Our proposed structure and investigation may pave the way for fundamental research of nanosensor applications and designs in highly integrated optical circuits.

Correlated noise-based switches and stochastic resonance in a bistable genetic regulation system

NASA Astrophysics Data System (ADS)

Wang, Can-Jun; Yang, Ke-Li

2016-07-01

The correlated noise-based switches and stochastic resonance are investigated in a bistable single gene switching system driven by an additive noise (environmental fluctuations), a multiplicative noise (fluctuations of the degradation rate). The correlation between the two noise sources originates from on the lysis-lysogeny pathway system of the λ phage. The steady state probability distribution is obtained by solving the time-independent Fokker-Planck equation, and the effects of noises are analyzed. The effects of noises on the switching time between the two stable states (mean first passage time) is investigated by the numerical simulation. The stochastic resonance phenomenon is analyzed by the power amplification factor. The results show that the multiplicative noise can induce the switching from "on" → "off" of the protein production, while the additive noise and the correlation between the noise sources can induce the inverse switching "off" → "on". A nonmonotonic behaviour of the average switching time versus the multiplicative noise intensity, for different cross-correlation and additive noise intensities, is observed in the genetic system. There exist optimal values of the additive noise, multiplicative noise and cross-correlation intensities for which the weak signal can be optimal amplified.

Internal Resonance in a Vibrating Beam: A Zoo of Nonlinear Resonance Peaks

PubMed Central

Mangussi, Franco

2016-01-01

In oscillating mechanical systems, nonlinearity is responsible for the departure from proportionality between the forces that sustain their motion and the resulting vibration amplitude. Such effect may have both beneficial and harmful effects in a broad class of technological applications, ranging from microelectromechanical devices to edifice structures. The dependence of the oscillation frequency on the amplitude, in particular, jeopardizes the use of nonlinear oscillators in the design of time-keeping electronic components. Nonlinearity, however, can itself counteract this adverse response by triggering a resonant interaction between different oscillation modes, which transfers the excess of energy in the main oscillation to higher harmonics, and thus stabilizes its frequency. In this paper, we examine a model for internal resonance in a vibrating elastic beam clamped at its two ends. In this case, nonlinearity occurs in the form of a restoring force proportional to the cube of the oscillation amplitude, which induces resonance between modes whose frequencies are in a ratio close to 1:3. The model is based on a representation of the resonant modes as two Duffing oscillators, coupled through cubic interactions. Our focus is put on illustrating the diversity of behavior that internal resonance brings about in the dynamical response of the system, depending on the detailed form of the coupling forces. The mathematical treatment of the model is developed at several approximation levels. A qualitative comparison of our results with previous experiments and numerical calculations on elastic beams is outlined. PMID:27648829

Optical resonator

NASA Technical Reports Server (NTRS)

Taghavi-Larigani, Shervin (Inventor); Vanzyl, Jakob J. (Inventor); Yariv, Amnon (Inventor)

2006-01-01

The invention discloses a semi-ring Fabry-Perot (SRFP) optical resonator structure comprising a medium including an edge forming a reflective facet and a waveguide within the medium, the waveguide having opposing ends formed by the reflective facet. The performance of the SRFP resonator can be further enhanced by including a Mach-Zehnder interferometer in the waveguide on one side of the gain medium. The optical resonator can be employed in a variety of optical devices. Laser structures using at least one SRFP resonator are disclosed where the resonators are disposed on opposite sides of a gain medium. Other laser structures employing one or more resonators on one side of a gain region are also disclosed.

Dataset of surface plasmon resonance based on photonic crystal fiber for chemical sensing applications.

PubMed

Khalek, Md Abdul; Chakma, Sujan; Paul, Bikash Kumar; Ahmed, Kawsar

2018-08-01

In this research work a perfectly circular lattice Photonic Crystal Fiber (PCF) based surface Plasmon resonance (SPR) based sensor has been proposed. The investigation process has been successfully carried out using finite element method (FEM) based commercial available software package COMSOL Multiphysics version 4.2. The whole investigation module covers the wider optical spectrum ranging from 0.48 µm to 1.10 µm. Using the wavelength interrogation method the proposed model exposed maximum sensitivity of 9000 nm/RIU(Refractive Index Unit) and using the amplitude interrogation method it obtained maximum sensitivity of 318 RIU -1 . Moreover the maximum sensor resolution of 1.11×10 -5 in the sensing ranges between 1.34 and 1.37. Based on the suggested sensor model may provide great impact in biological area such as bio-imaging.

SS-HORSE method for studying resonances

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blokhintsev, L. D.; Mazur, A. I.; Mazur, I. A., E-mail: 008043@pnu.edu.ru

A new method for analyzing resonance states based on the Harmonic-Oscillator Representation of Scattering Equations (HORSE) formalism and analytic properties of partial-wave scattering amplitudes is proposed. The method is tested by applying it to the model problem of neutral-particle scattering and can be used to study resonance states on the basis of microscopic calculations performed within various versions of the shell model.

Design of a compact polarizing beam splitter based on a photonic crystal ring resonator with a triangular lattice.

PubMed

Yu, Tianbao; Huang, Jiehui; Liu, Nianhua; Yang, Jianyi; Liao, Qinghua; Jiang, Xiaoqing

2010-04-10

We propose and simulate a new kind of compact polarizing beam splitter (PBS) based on a photonic crystal ring resonator (PCRR) with complete photonic bandgaps. The two polarized states are separated far enough by resonant and nonresonant coupling between the waveguide modes and the microring modes. Some defect holes are utilized to control the beam propagation. The simulated results obtained by the finite-difference time-domain method show that high transmission (over 95%) is obtained and the polarization separation is realized with a length as short as 3.1 microm. The design of the proposed PBS can be flexible, thanks to the advantages of PCRRs.

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

PubMed

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

2015-04-23

In this paper, angular displacement and angular velocity sensors based on coplanar waveguide (CPW) transmission lines and S-shaped split ring resonators (S-SRRs) are presented. The sensor consists of two parts, namely a CPW and an S-SRR, both lying on parallel planes. By this means, line-to-resonator magnetic coupling arises, the coupling level being dependent on the line-to-resonator relative angular orientation. The line-to-resonator coupling level is the key parameter responsible for modulating the amplitude of the frequency response seen between the CPW ports in the vicinity of the S-SRR fundamental resonance frequency. Specifically, an amplitude notch that can be visualized in the transmission coefficient is changed by the coupling strength, and it is characterized as the sensing variable. Thus, the relative angular orientation between the two parts is measured, when the S-SRR is attached to a rotating object. It follows that the rotation angle and speed can be inferred either by measuring the frequency response of the S-SRR-loaded line, or the response amplitude at a fixed frequency in the vicinity of resonance. It is in addition shown that the angular velocity can be accurately determined from the time-domain response of a carrier time-harmonic signal tuned at the S-SRR resonance frequency. The main advantage of the proposed device is its small size directly related to the small electrical size of the S-SRR, which allows for the design of compact angular displacement and velocity sensors at low frequencies. Despite the small size of the fabricated proof-of-concept prototype (electrically small structures do not usually reject signals efficiently), it exhibits good linearity (on a logarithmic scale), sensitivity and dynamic range.

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

PubMed Central

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

2015-01-01

In this paper, angular displacement and angular velocity sensors based on coplanar waveguide (CPW) transmission lines and S-shaped split ring resonators (S-SRRs) are presented. The sensor consists of two parts, namely a CPW and an S-SRR, both lying on parallel planes. By this means, line-to-resonator magnetic coupling arises, the coupling level being dependent on the line-to-resonator relative angular orientation. The line-to-resonator coupling level is the key parameter responsible for modulating the amplitude of the frequency response seen between the CPW ports in the vicinity of the S-SRR fundamental resonance frequency. Specifically, an amplitude notch that can be visualized in the transmission coefficient is changed by the coupling strength, and it is characterized as the sensing variable. Thus, the relative angular orientation between the two parts is measured, when the S-SRR is attached to a rotating object. It follows that the rotation angle and speed can be inferred either by measuring the frequency response of the S-SRR-loaded line, or the response amplitude at a fixed frequency in the vicinity of resonance. It is in addition shown that the angular velocity can be accurately determined from the time-domain response of a carrier time-harmonic signal tuned at the S-SRR resonance frequency. The main advantage of the proposed device is its small size directly related to the small electrical size of the S-SRR, which allows for the design of compact angular displacement and velocity sensors at low frequencies. Despite the small size of the fabricated proof-of-concept prototype (electrically small structures do not usually reject signals efficiently), it exhibits good linearity (on a logarithmic scale), sensitivity and dynamic range. PMID:25915590

An elastography method based on the scanning contact resonance of a piezoelectric cantilever

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fu, Ji; Li, Faxin, E-mail: lifaxin@pku.edu.cn

2013-12-15

Purpose: Most tissues may become significantly stiffer than their normal states when there are lesions inside. The tissue's modulus can then act as an identification parameter for clinic diagnosis of tumors or fibrosis, which leads to elastography. This study introduces a novel elastography method that can be used for modulus imaging of superficial organs. Methods: This method is based on the scanning contact-resonance of a unimorph piezoelectric cantilever. The cantilever vibrates in its bending mode with the tip pressed tightly on the sample. The contact resonance frequency of the cantilever-sample system is tracked at each scanning point, from which themore » sample's modulus can be derived based on a beam dynamic model and a contact mechanics model. Scanning is performed by a three-dimensional motorized stage and the whole system is controlled by a homemade software program based on LabVIEW. Results: Testing onin vitro beef tissues indicates that the fat and the muscle can be easily distinguished using this system, and the accuracy of the modulus measurement can be comparable with that of nanoindentation. Imaging on homemade gelatin phantoms shows that the depth information of the abnormalities can be qualitatively obtained by varying the pressing force. The detection limit of this elastography method is specially examined both experimentally and numerically. Results show that it can detect the typical lesions in superficial organs with the depth of several centimeters. The lateral resolution of this elastography method/system is better than 0.5 mm, and could be further enhanced by using more scanning points. Conclusions: The proposed elastography system can be regarded as a sensitive palpation robot, which may be very promising in early diagnosis of tumors in superficial organs such as breast and thyroid.« less

Resonant tunneling diodes based on ZnO for quantum cascade structures (Conference Presentation)

NASA Astrophysics Data System (ADS)

Hinkov, Borislav; Schwarz, Benedikt; Harrer, Andreas; Ristanic, Daniela; Schrenk, Werner; Hugues, Maxime; Chauveau, Jean-Michel; Strasser, Gottfried

2017-02-01

The terahertz (THz) spectral range (lambda 30µm - 300µm) is also known as the "THz-gap" because of the lack of compact semiconductor devices. Various real-world applications would strongly benefit from such sources like trace-gas spectroscopy or security-screening. A crucial step is the operation of THz-emitting lasers at room temperature. But this seems out of reach with current devices, of which GaAs-based quantum cascade lasers (QCLs) seem to be the most promising ones. They are limited by the parasitic, non-optical LO-phonon transitions (36meV in GaAs), being on the same order as the thermal energy at room temperature (kT = 26meV). This can be solved by using larger LO-phonon materials like ZnO (E_LO = 72meV). But to master the fabrication of ZnO-based QC structures, a high quality epitaxial growth is crucial followed by a well-controlled fabrication process including ZnO/ZnMgO etching. We use devices grown on m-plane ZnO-substrate by molecular beam epitaxy. They are patterned by reactive ion etching in a CH4-based chemistry (CH4:H2:Ar/30:3:3 sccm) into 50μm to 150μm square mesas. Resonant tunneling diode structures are investigated in this geometry and are presented including different barrier- and well-configurations. We extract contact resistances of 8e-5 Omega cm^2 for un-annealed Ti/Au contacts and an electron mobility of above 130cm^2/Vs, both in good agreement with literature. Proving that resonant electron tunneling can be achieved in ZnO is one of the crucial building blocks of a QCL. This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 665107.