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Dissertations / Theses on the topic 'Surface acoustics wave'

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Published: 8 June 2024

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1

Chiu, Ching-Sang Denner Warren W. "Report on the Office of Naval Research USA-China Conference on Shallow Water Acoustics, December 18-21, 1995." Monterey, CA : Naval Postgraduate School, 1997. http://catalog.hathitrust.org/api/volumes/oclc/37486128.html.

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2

Hughes, Adrian. "Transduction and guidance by narrow aperture surface acoustic wave structures." Thesis, University of Oxford, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.236172.

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3

Blake, Christina Diane. "Narrow apperture surface acoustic wave transducers and their application in spectrum analysis." Thesis, University of Oxford, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329903.

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4

Buchine, Brent Alan. "Acoustics in nanotechnology: manipulation, device application and modeling." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/26542.

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Thesis (Ph.D)--Materials Science and Engineering, Georgia Institute of Technology, 2008.
Committee Chair: Wang, Zhong Lin; Committee Member: Degertekin, F. Levent; Committee Member: Liu, Meilin; Committee Member: Snyder, Robert L.; Committee Member: Tannenbaum, Rina. Part of the SMARTech Electronic Thesis and Dissertation Collection.

5

Du, Xinpeng. "Laser-Ultrasonic Measurement of Single-Crystal Elastic Constants from Polycrystalline Samples by Measuring and Modeling Surface Acoustic Wave Velocities." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1524177819455643.

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6

Freed, Shaun L. "High Resolution Ultrasonic Rayleigh Wave Interrogation of a Thermally Aged Polymeric Surface." University of Dayton / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1291685460.

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7

Blimbaum, Jordan Matthew. "Finite element analysis of acoustic wave transverse to longitudinal coupling during transverse combustion instability." Thesis, Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/44757.

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Velocity-coupled combustion instability is a major issue facing lean combustor design in modern gas turbine applications. In this study, we analyze the complex acoustic field excited by a transverse acoustic mode in an annular combustor. This work is motivated by the need to understand the various velocity disturbance mechanisms present in the flame region during a transverse instability event. Recent simulation and experimental studies have shown that much of the flame response during these transverse instabilities may be due to the longitudinal motion induced by the fluctuating pressure field above the nozzles. This transverse to longitudinal coupling has been discussed in previous work, but in this work it is given a robust acoustic treatment via computational methods in order to verify the mechanisms by which these two motions couple. We will provide an in-depth discussion of this coupling mechanism and propose a parameter, Rz, also referred to as the Impedance Ratio, in order to compare the pressure/velocity relationship at the nozzle outlet to quasi one-dimensional theoretical acoustic approximations. A three-dimensional inviscid simulation was developed to simulate transversely propagating acoustic pressure waves, based on an earlier experiment designed to measure these effects. Modifications to this geometry have been made to account for lack of viscosity in the pure acoustic simulation and are discussed. Results from this study show that transverse acoustic pressure excites significant axial motion in and around the nozzle over a large range of frequencies. Furthermore, the development of Rz offers a defined physical parameter through which to reference this important velocity-coupled instability mechanism. Therefore, this study offers an in-depth and quantifiable understanding of the instability mechanism caused by transversely propagating acoustic waves across a combustor inlet, which can be applied to greatly improve annular combustor design in future low-emissions gas turbine engines.

8

Haskell, Reichl B. "A Surface Acoustic Wave Mercury Vapor Sensor." Fogler Library, University of Maine, 2003. http://www.library.umaine.edu/theses/pdf/HaskellRB2003.pdf.

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9

Wang, TingTing. "Acoustic / elastic wave propagation in coupled-resonator waveguides." Thesis, Bourgogne Franche-Comté, 2020. http://www.theses.fr/2020UBFCD061.

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Lorsqu'un défaut est introduit dans un cristal phononique, des états apparaissent dans les bandes interdites et se localisent au niveau des défauts. Ils décroissent rapidement loin du défaut. Par conséquent, il est possible de localiser et de guider la propagation des ondes en concevant des défauts dans un cristal phononique parfait. Le guide d’onde à résonateurs couplés, fondé sur le couplage d'une séquence de cavités, présente simultanément un fort confinement des ondes et une faible vitesse de groupe ; il peut être utilisé pour concevoir des circuits plutôt arbitraires. En outre, la propagation des ondes élastiques dans une matrice solide peut être contrôlée en remplissant des cavités d'un fluide, sur la base des systèmes couplés fluides-solides. Ils ont des applications essentielles pour la réduction des vibrations et l’isolation acoustique. Dans cette thèse, les ondes acoustiques et élastiques se propageant dans les guides d’ondes à résonateurs couplés périodiques et apériodiques sont étudiées. L’interaction fluide-solide dans les cristaux phononiques fluide / solide est étudiée. Les travaux sont menés en combinant simulation numérique, analyse par modèles théoriques et investigation expérimentale
When a defect is introduced into a phononic crystal, states localized at the defect appear in the band gaps. They decay rapidly far away from the defect. Therefore, it is possible to localize and guide wave propagation by designing defects in the perfect phononic crystal. Coupled-resonator waveguides based on the coupling effect between a sequence of defect cavities have simultaneously strong wave confinement and low group velocity, and can be used to design rather arbitrary circuits. Furthermore, the propagation of elastic waves in a solid matrix can be controlled through changing fluid fillings based on fluid-solid interaction. Thus, they have essential applications in vibration reduction and noise isolation. In this thesis, the acoustic and elastic waves propagating in both periodic and aperiodic coupled-resonator waveguides are investigated. The fluid-solid interaction in fluid/solid phononic crystals is studied. The work is conducted by combining numerical simulations, theoretical model analysis and experimental investigations

10

Riaud, Antoine Jean-Pierre René. "Etude des potentialités offertes par la synthèse de champs d'ondes acoustiques de surface pour l'actionnement de liquides et la manipulation sans contact." Thesis, Ecole centrale de Lille, 2016. http://www.theses.fr/2016ECLI0010/document.

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Lorsque des ondes acoustiques de surface rayonnent dans des fluides, elles provoquent deux effets non linéaires : la pression de radiation et le streaming acoustique. Ces deux effets ont trouvé un grand nombre d’applications pour la microfluidique digitale, la manipulation sans contact et le tri cellulaire. Néanmoins, ces systèmes se heurtent à deux limites. D’une part, chaque application requiert une onde acoustique spécifique : il n’existe pas de dispositif multifonction à ce jour. D’autre part, l’exploration des fonctionnalités offertes par les ondes de surface les plus simples (ondes planes, ondes focalisées) n’a pas permis de réaliser des pinces sélectives permettant de manipuler individuellement des particules ou cellules indépendamment de leurs voisines.Dans une première partie de la thèse, nous développons deux méthodologies pour synthétiser des champs complexes d’ondes de surface. La première méthode utilise un réseau de 32 peignes interdigités contrôlé par la technique du filtre inverse pour générer des champs sur demande. La seconde résout un problème inverse afin de concevoir un transducteur holographique générant spécifiquement le champ demandé. Dans la seconde partie de la thèse, nous utilisons le filtre inverse pour (i) réaliser un laboratoire sur puce multifonction et (ii) étudier le potentiel d’ondes de surface particulières appelées ondes de surface tourbillonnaires. Ces ondes permettent une manipulation sélective et sans contact d’objets microscopiques. Nous terminons la thèse en équipant un microscope d’un transducteur holographique de vortex acoustiques afin de réaliser une manipulation sélective et sans contact de cellules
When surface acoustic waves radiate in nearby fluids, they trigger two nonlinear effects: acoustic radiation pressure and acoustic streaming. These two effects find numerous applications for digital microfluidics, contactless manipulation and biological cell sorting. Nonetheless, these systems face two limitations. On the one hand, each application requires a specific acoustic wave: there is no multifunction device so far. On the other hand, search for functionalities offered by simple surface acoustic waves (plane and focused waves) has failed to provide a selective tweezers able to manipulate individual particles or cells independently of their neighbors. In the first part of this thesis, we develop two methods to synthesize complex surface acoustic wave fields. The first one employs an array of 32 interdigitated transducers controlled by the inverse filter to generate arbitrary fields on demand. The second method solves an inverse problem to design a holographic transducer to generate a predefined field. In the second part of the thesis, we use the inverse filter to (i) implement a multifunction lab on a chip and (ii) investigate the potentialities of a special type of surface acoustic waves called swirling surface waves. These waves enable a selective and contactless manipulation of microscopic objects. We conclude the thesis by integrating a holographic acoustical vortex transducer on a microscope in order to selectively manipulate biological cells without contact

11

Kumon, Ronald Edward. "Nonlinear surface acoustic waves in cubic crystals /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.

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12

Tan, Lin. "Development of micro-acoustic devices with applications of viscous effects." Diss., Online access via UMI:, 2006.

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13

Hong, Stanley Seokjong 1977. "Surface acoustic wave optical modulation." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/86715.

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Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2001.
Includes bibliographical references (leaves 50-54).
by Stanley Seokjong Hong.
M.Eng.

14

Sen, Rahul. "Acoustic scattering by discontinuities in waveguides." Diss., Virginia Polytechnic Institute and State University, 1988. http://hdl.handle.net/10919/81021.

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The scattering of acoustic waves by boundary discontinuities in waveguides is analyzed using the Method of Matched Asymptotic Expansions (MAE). Existing theories are accurate only for very low frequencies. In contrast, the theory developed in this thesis is valid over the entire range of frequencies up to the first cutoff frequency. The key to this improvement lies in recognizing the important physical role of the cutoff cross-modes of the waveguide, which are usually overlooked. Although these modes are evanescent, they contain information about the interaction between the local field near the discontinuity and the far-field. This interaction has a profound effect on the far-field amplitudes and becomes increasingly important with frequency. The cutoff modes also present novel mathematical problems in that current asymptotic techniques do not offer a rational means of incorporating them into a mathematical description. This difficulty arises from the non-Poincare form of the cross-modes, and its resolution constitutes the second new result of this thesis. We develop a matching scheme based on block matching intermediate expansions in a transform domain. The new technique permits the matching of expansions of a more general nature than previously possible, and may well have useful applications in other physical situations where evanescent terms are important. We show that the resulting theory leads to significant improvements with just a few cross-mode terms included, and also that there is an intimate connection with classical integral methods. Finally, the theory is extended to waveguides with slowly varying shape. We show that the usual regular perturbation analysis of the wave regions must be completely abandoned. This is due to the evanescent nature of the cross-modes, which must be described by a WKB approximation. The pressure field we so obtain includes older results. The new terms account for the cutoff cross-modes of the variable waveguide, which play a central role in extending the dynamic range of the theory.
Ph. D.

15

Hay, Robert Russell. "Digitally-tunable surface acoustic wave resonator." [Boise, Idaho] : Boise State University, 2009. http://scholarworks.boisestate.edu/td/58/.

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16

McNeil, Robert Peter Gordon. "Surface acoustic wave quantum electronic devices." Thesis, University of Cambridge, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.610718.

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17

Kaplan, Emrah. "Surface acoustic wave enhanced electroanalytical sensors." Thesis, University of Glasgow, 2015. http://theses.gla.ac.uk/6557/.

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In the last decade, miniaturised “lab-on-a-chip” (LOC) devices have attracted significant interest in academia and industry. LOC sensors for electrochemical analysis now commonly reach picomolar in sensitivities, using only microliter-sized samples. One of the major drawbacks of this platform is the diffusion layer that appears as a limiting factor for the sensitivity level. In this thesis, a new technique was developed to enhance the sensitivity of electroanalytical sensors by increasing the mass transfer in the medium. The final device design was to be used for early detection of cancer diseases which causes bleeding in the digestive system. The diagnostic device was proposed to give reliable and repeatable results by additional modifications on its design. The sensitivity enhanced-sensor model was achieved by combining the surface acoustic wave (SAW) technology with the electroanalytical sensing platform. The technique was practically tested on a diagnostic device model and a biosensing platform. A novel, substrate (TMB) based label-free Hb sensing method is developed and tested. Moreover, the technique was further developed by changing the sensing process. Instead of forming the sensitive layer on the electrodes it was localised on polystyrene wells by a rapid one-step process. Results showed that the use of acoustic streaming, generated by SAW, increases the current flow and improves the sensitivity of amperometric sensors by a factor of 6 while only requiring microliter scale sample volumes. The heating and streaming induced by the SAW removes the small random contributions made by the natural convection and temperature variation which complicate the measurements. Therefore, the method offers stabilised conditions for more reliable and repeatable measurements. The label-free detection technique proved to be giving relevant data, according to the hemoglobin concentration. It has fewer steps than ELISA and has only one antibody. Therefore, it is quick and the cross-reactivity of the second antibody is eliminated from the system. The additional modifications made on the technique decreased the time to prepare the sensing platform because the passivation steps (i.e., pegylation), prior to structuring a sensitive layer were ignored. This avoidance also increased the reliability and repeatability of the measurements.

18

Reese, Owein. "Homogenization of acoustic wave propagation in a magnetorheological fluid." Link to electronic thesis, 2004. http://www.wpi.edu/Pubs/ETD/Available/etd-0430104-101629.

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19

Lin, Yiqiang Farouk Bakhtier. "Acoustic wave induced convection and transport in gases under normal and micro-gravity conditions /." Philadelphia, Pa. : Drexel University, 2007. http://hdl.handle.net/1860/1795.

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20

Kenny, Thomas Donald. "Identification of High-Velocity Pseudo-surface Acoustic Wave Substrate Orientations and Modeling of Surface Acoustic Wave Structures." Fogler Library, University of Maine, 2011. http://www.library.umaine.edu/theses/pdf/KennyT2011.pdf.

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21

Rinker, Brett A. "A single-sided access simultaneous solution of acoustic wave speed and sample thickness for isotropic materials of plate-type geometry." Diss., Columbia, Mo. : University of Missouri-Columbia, 2006. http://hdl.handle.net/10355/4585.

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Thesis (M.S.)--University of Missouri-Columbia, 2006.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on April 17, 2009) Vita. Includes bibliographical references.

22

Gizeli, Electra. "New acoustic wave sensor geometries." Thesis, University of Cambridge, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282004.

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23

Schlottmann, Robert Brian. "A path integral formulation of elastic wave propagation /." Full text (PDF) from UMI/Dissertation Abstracts International, 2000. http://wwwlib.umi.com/cr/utexas/fullcit?p3004372.

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24

Bright, Victor M. "Shear horizontal surface acoustic waves." Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/14831.

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25

Thorn, Adam Leslie. "Electron dynamics in surface acoustic wave devices." Thesis, University of Cambridge, 2009. https://www.repository.cam.ac.uk/handle/1810/224176.

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Gallium arsenide is piezoelectric, so it is possible to generate coupled mechanical and electrical surface acoustic waves (SAWs) by applying a high-frequency voltage to a transducer on the surface of GaAs. By combining SAWs with existing low-dimensional nanostructures one can create a series of dynamic quantum dots corresponding to the minima of the travelling electric wave, and each dot carries a single electron at the SAW velocity (~ 2800 m/s). These devices may be of use in developing future quantum information processors, and also offer an ideal environment for probing the quantum mechanical behaviour of single electrons. This thesis describes a numerical and theoretical study of the dynamics ofan electron in a range of geometries. The numerical techniques for solving thetime-dependent Schrödinger equation with an arbitrary time-dependent potential will be described in Chapter 2, and then applied in Chapter 3 to calculate the transmission of an electron through an Aharonov-Bohm (AB) ring. It will be seen that an important property of the techniques used in this thesis is that they can be easily adapted to study realistic geometries, and we will see features in the AB oscillations which do not arise in simplified analytic descriptions. In Chapter 4, we will then study a device consisting of two parallel SAW channels separated by a controllable tunnelling barrier. We will use numerical simulations to investigate the effect of electric and magnetic fields upon the electron dynamics, and develop an analytic model to explain the simulation results. From the model, it will be apparent that it is possible to use this device to rotatethe state of the electron to an arbitrary superposition of the first two eigenstates. We then introduce coherent and squeezed states in Chapter 5, which are ex-cited states of the quantum harmonic oscillator. Coherent and squeezed electronicstates may be of use in quantum information processing, and could also arise dueto unwanted perturbations in a SAW device. We will discuss how these statescan be controllably generated in a SAW device, and also discuss how they couldthen be detected. In Chapter 6 we describe how to use the motion of a SAW to create a rapidly-changing potential in the frame of the electron, leading to a nonadiabatic excita-tion. The nonadiabatically-excited state oscillates from side to side within a 1Dchannel on a few-picosecond timescale, and this motion can be probed by placing a tunnelling barrier at one side of the channel. Numerical simulations will beperformed to show how this motion can be controlled, and the simulation resultswill be seen to be in good agreement with recent experimental work performed by colleagues. Finally, we will show that this device can be used to measure the initial state of an electron which is an arbitrary superposition of the first twoeigenstates.

26

Astley, Michael Robert. "Surface-acoustic-wave-defined dynamic quantum dots." Thesis, University of Cambridge, 2008. https://www.repository.cam.ac.uk/handle/1810/261973.

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The strain associated with a surface acoustic wave (SAW) propagating across a piezoelectric medium creates a travelling electric potential. Gallium Arsenide is such a piezoelectric material, and so SAWs can be used with existing semiconductor technologies for creating complex low-dimensional nanostructures. A SAW travelling along an empty quasi-one-dimensional channel creates a series of dynamic quantum dots which can transport electrons at the SAW velocity (∼ 2800 ms−1 ), allowing high-frequency operations to be carried out on the electron without the need for fast pulsed-gate techniques. Such dynamic quantum dot devices can provide valuable insights into fundamental physical phenomena and could have technological applications in quantum information processing. This thesis details investigations into SAW-defined dynamic quantum dot devices. Chapter 1 introduces the scientific background to the experiments described in this thesis; Chapter 2 provides details of the processing and measurement techniques used to perform these experiments. Chapter 3 consists of a study into the effect that reflections have on the acousto-electric current generated in a SAW channel. Reflections create a modulation to the channel entrance potential which is critical in determining the magnitude of the acousto-electric current. As the frequency of the SAW is varied, a particular reflection creates a periodic interference with the main SAW driving the current which can be observed in the Fourier transform of the acousto-electric current’s frequency dependence. The period of these oscillations is directly related to the distance which the reflection has travelled relative to the main SAW, which allows the principle reflection mechanisms to be characterised. Reflections persisted on a SAW device for large amounts of time, giving rise to much of the “noise” seen in the frequency dependence, and the pattern of reflections was found to be chaotic. Chapters 4-8 show the results obtained with a device where two SAW channels were linked by a tunnel barrier. This device allowed quantum mechanical tunnelling of electrons from the dynamic quantum dots to be observed over a subnanosecond timescale. Chapter 5 describes how the escape rates of the electrons from dynamic quantum dots can be measured using a rate equation analysis, and these rates are fit to a simple tunnelling model to derive the addition energies of the dynamic quantum dots. In Chapter 6 the tunnelling current was found to contain low-visibility oscillations, which cannot be explained by simple models. It is thought that these oscillations are caused by the non-adiabatic time-evolution of the electron wave function when the tunnel barrier is lowered suddenly. Chapter 7 shows how a crosstalk current through a short constriction is sensitive to local potential changes in an analogous manner to a quantum point contact, and how this effect can be used to detect the occupation of dynamic quantum dots in a nearby SAW channel. Chapter 8 collects some minor observations which have been made whilst studying the tunnel barrier device. In Chapter 9 I present the conclusions of the experiments presented in this thesis, and provide some ideas for future directions this work may take.

27

Du, X. "Surface acoustic wave devices for microfluidic applications." Thesis, University of Cambridge, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.598662.

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This project investigates the use of surface acoustic waves (SAWs) for applications in low cost, low voltage, digital microfluidic systems. To be able to produce surface acoustic waves, the substrate of the microfluidic device needs to be a piezoelectric material. This study explored the use of two different substrates: 128° Y-cut lithium Niobate (LiNbO₃) and RF magnetron sputtered Zinc Oxide(ZnO) on Silicon (Si) (100). The SAW device incorporates aluminium InterDigital Transducers (IDTs) on LiNbO₃ and ZnO/Si piezoelectric material that acts as an excitation agent to create a surface wave on the substrate. When the signal through the IDT matches the correct frequency, a mechanical wave propagates away from the IDT on the substrate surface. Droplet mixing and movement experiments demonstrate a linear relationship between the applied voltage and droplet movement. Other factors tested are the surface treatment effect on droplet movement and surface temperature effects caused by the SAW mechanical wave. Before droplets could be moved a hydrophobic coating had to be deposited on the surface. The surface coating utilizes the octadecytrichlorosilane (OTS) for both its chemical inertness and bio-compatibility. The OTS coating is smooth and thin and does not effect the propagation of the SAW. The propagation mode of the acoustic wave is determined by the structure of the SAW devices and materials. A higher order harmonic mode wave appears in addition to the fundamental Rayleigh wave for LiNbO₃ samples. The Rayleigh mode and higher mode- Sezawa mode can be induced for the ZnO/Si SAW devices. These different wave modes have been utilized to induce streaming and manipulate liquid droplets for microfluidic application.

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Gell, Jennifer Rachel. "Surface-acoustic-wave (SAW) driven light sources." Thesis, University of Cambridge, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.599350.

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This thesis concentrates on the interaction between SAWs (surface acoustic wave) and low-dimensional systems studied using optical techniques. In particular SAW-driven luminescence from a lateral p-n junction is demonstrated. The lateral p-n junction is formed by molecular beam epitaxy regrowth on a patterned GaAs substrate. Silicon is used as an amphoteric dopant to create a high mobility two-dimensional electron gas on flat (100) planes and a two-dimensional hole gas on angled (311)A facets. A lateral p-n junction is formed at the interface between these planes. SAWs with a frequency of ~1 GHz are generated using an interdigitated transducer. When a continuous radio frequency (RF) signal is used to excite the transducer, SAW-driven light emission from the p-n junction is demonstrated by peaks in the current/light emission at the resonant frequency of the transducer. To investigate the nature of the luminescence further, short RF pulses are used to drive the transducer. The short pulses temporally isolate the SAW-driven light emission from any emission due unwanted pick-up of the free space electromagnetic wave. In the final section the modulation of the emission energies of a single self-assembled quantum dot by a SAW is investigated. The compression and expansion of the crystal due to the strain wave causes the energy of the dot lines to oscillate around their equilibrium values. The shape of the SAW broadened emission lines was seen to depend on the nature of the transition in the dot offering an alternative way of identifying charged and neutral species in this sample. The modulation of the dot energy levels by the SAW is used to control the time of photon emission from the system.

29

Sehra, Gurmukh S. "Surface acoustic wave based flavour sensor system." Thesis, University of Warwick, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.416148.

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Meng, Qingbin. "Surface acoustic wave controlled semiconductor optical source." Thesis, University of Bath, 2009. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.518122.

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A semiconductor optical source monolithically integrated with a surface acoustic wave (SAW) Bragg-cell to operate as a functional device is proposed in this thesis. The practical structure of such an integrated device is demonstrated and design guidelines are presented. Compared with conventional optical beam processed devices, this functional integrated semiconductor optical source (FISOS) is revised to be compact in size, flexible in function and potentially robust in performance.
The FISOS is analyzed as two sub-divisions, optical source and acoustic processor, which have the common substrate structure. The optical beams excited from the optical source part of the device undergoes a scattering in the Bragg grating formed by SAWs that are generated by an IDT positioned on top of the acoustic processing part of device. By altering the property (power, frequency, etc.) of the SAW, versatile functionalities such as modulation, filtering, beam steering and so on of the optical beams can be realized in this optical source device.
A multilayer structure based on GaN/InGaN MQWs grown on sapphire is designed for the FISOS to be blue light emitting and efficiently launching SAWs. An etch-down technique employed in the SAW processing part is taken to improve the overlap between the optical and acoustic waves and then the interaction efficiency. Optimizations to the geometrical dimensions of the FISOS, such the width of the ridge waveguide, the position of the IDT and the etching depth, etc., are discussed in the given structure.
Numerical models are investigated to access the operational characteristics and then to provide design guidelines for the proposed integrated device. The Bragg diffraction of optical waves occurring within the acoustic waves in the proposed structure are simulated as a two-dimensional interaction between two guided optical modes and an acoustic surface wave.
The modal distributions and propagation velocities of SAWs in a multilayer system are calculated using Adler’s matrix method. The electrical characteristics of an IDT, such as impedance, insertion loss, electromechanical constant and so on are also discussed.
Transverse and lateral optical modes in the given multilayer structure are analyzed by the transfer matrix method. The interaction of optical waves and acoustic waves are modeled using the rigorous grating diffraction theory. Starting from Floquet’s theory, the well-known coupled-wave method and modal method can both be derived from the rigorous grating diffraction theory. Discussions of some useful approximate methods are also presented. In this thesis, the simulations of the acoustooptic interaction are performed using the coupled-wave method.
From the simulation results, the angular distribution profile and spatial profile of the output of the FISOS are evaluated. An improvement to the expression of the diffraction efficiency in such an integrated device is proposed. The so-called beam diffraction efficiency gives a more complete measure to the acoustooptic diffraction and is used to investigate the features of FISOS different from conventional acoustooptic devices. Contour plots of the beam efficiency varying with acoustic frequency and power in a FISOS is demonstrated to be a convenient and powerful approach in the device design.
The operational performances of an integrated deflector and a modulator in FISOS are analyzed to investigate the feasibility of FISOS. The trade-off of the efficiency-resolution in an integrated deflector design is discussed. Short interaction length, high acoustic frequency and narrow ridge are proved to be helpful for a larger number of resolvable spots with a fairly high efficiency. In the case of the integrated modulator, given that the figure of merit Q is fixed, it is demonstrated that the smaller the Q, the longer the interaction length, larger ridge width and lower acoustic frequency will give rise to a larger bandwidth, though the highest efficiency might appear at a higher frequency.
Some practical issues such as the misalignment of planar elements on the device and the incoherence of the integrated optical source are also discussed. A modified working frequency can be used to compensate the efficiency loss in the former case; in the latter case, it is demonstrated that a distortion of beam diffraction efficiency versus acoustic power with an incoherent optical source arises due to the wide spectrum of the incident optical waves.

31

Ead, Richard M. "Predicting the effects of sea surface scatter on broad band pulse propagation with an ocean acoustic parabolic equation model." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2004. http://library.nps.navy.mil/uhtbin/hyperion/04Jun%5FEad.pdf.

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Banerjee, Markus K. "Acoustic wave interactions with viscous liquids spreading in the acoustic path of a surface acoustic wave sensor." Thesis, Nottingham Trent University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302521.

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33

Kitabayashi, Hiroyuki. "Surface acoustic wave filters on diamond layered structures /." *McMaster only, 2001.

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34

Alghane, Mansuor Mohamed. "Surface acoustic wave streaming in a microfluidic system." Thesis, Heriot-Watt University, 2013. http://hdl.handle.net/10399/2645.

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35

Khalid, Muhammad Arslan. "Engineering surface acoustic wave sensing and diagnostic devices." Thesis, University of Glasgow, 2017. http://theses.gla.ac.uk/30999/.

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Abstract:

Globally, over 50% of deaths occur due to the top 10 global diseases which include cardiovascular disease, cancer and infectious diseases. Low and middle-income countries (LMICs) are disproportionately affected. 80% of all deaths due to non-communicable diseases occur in low and middle income countries and with numbers on the rise. In these disadvantaged and vulnerable populations, diseases are often detected late. The treatment required is therefore increasingly extensive and expensive. Early detection, treatment and monitoring coupled with life-style changes can reduce mortality and morbidity. Many laboratory and clinical diagnostic tests have been developed. However, in order to provide healthcare in resource poor areas near the patient side (point-of-care), portable and low-cost bioanalytical assays are required. Lab-on-a-chip technology has emerged as a contender for point-of-care testing and monitoring but due to the complexity of the systems, there has been limited success in miniaturisation of fully integrated assays. This thesis takes a new approach to make use of existing and readily available mobile technologies to engineer on-chip, integrated, portable and low-cost microfluidic platforms using surface acoustic waves (SAW). The ability of SAW to manipulate fluids has been used to develop therapeutic and sensing devices. In the first application, SAW acoustic streaming was used to mechanically ‘clot’ or ‘solidify’ a droplet of human whole blood containing anti-coagulants in as quickly as 6 seconds. To analyse this mechanical process of a change in state, in small sample volumes, a new method which used light deflection from the surface perturbations was developed which could potentially replace clinical thromboelastography. The higher order acoustic streaming is known to be significantly influenced by a fluid’s viscosity. In a second application, as a proof of concept, it was demonstrated that the drop vibration due to SAW streaming together with the light deflection method can be used to study the relative viscosity response in samples. Furthermore, to aid the development of an integrated digital microfluidics, such as a blood monitoring device, a low cost (~$65) smart-phone based SAW platform prototype has been built using additive manufacturing technologies. Many lab-on-chip devices rely on optical detection such as microscopes. SAW already have shown promise in fluid manipulation and can eliminate the need for external pumps in sample processing. However, optical detection remains a challenge to create truly point-of-care devices. In this thesis, integration of SAW with portable lens-free microscopy that offers a large field of view (FOV) (~30 mm2) is demonstrated. Furthermore, a new method has been proposed for label-free visualisation of waves in fluids and to study their rheological response by analysing the wave relaxation process. This method can potentially be developed into a high-throughput viscosity sensor for disease diagnostics. Finally, by coupling SAW in transmissive superstrates (a low-cost disposable chip), acoustically tuneable nanolenses were created which allowed the detection of sub-micron particles in liquids without super-resolution techniques. As an application of this technique, detection of herpes simplex virus (type I) has been shown. In summary, this thesis presents the potential of SAW through its integration with mobile platforms such as a smartphone or lens-free microscope to engineer label-free, low-cost and high-throughput sensing and testing devices.

36

Friedlander, Jeffrey B. "Wireless Strain Measurement with Surface Acoustic Wave Sensors." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1306874020.

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37

Tew, R. "Imaging theory of surface-breaking discontinuities." Thesis, University of Oxford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380008.

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38

Gross, Johann. "Evaluation of near surface material degradation in concrete using nonlinear Rayleigh surface waves." Thesis, Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/45810.

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Abstract:

Comparative studies of nondestructive evaluation methods have shown that nonlinear ultrasonic techniques are more sensitive than conventional linear methods to changes in material microstructure and the associated small-scale damage. Many of the material degradation processes such as carbonation in concrete, corrosion in metals, etc., begin at the surface. In such cases, ultrasonic Rayleigh surface waves are especially appropriate for detection and characterization of damage since their energy is concentrated in the top layer of the test object. For the civil engineering infrastructure, only a limited number of field applicable nonlinear ultrasonic techniques have been introduced. In this paper a nonlinear ultrasonic measurement technique based on the use of Rayleigh waves is developed and used to characterize carbonation in concrete samples. Wedge transducer is used for the generation and an accelerometer for detection of the fundamental and modulated ultrasonic signal components. The measurements are made by varying the input voltage and along the propagation distance. The slope of the normalized modulated amplitudes is taken as the respective nonlinearity parameter. Concrete samples with two different levels of damage are examined, and the difference of the two fundamental frequencies is used to quantify damage state.

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Kavalov, Dimitar A. "Surface acoustic wave neural networks for RF signal processing." Thesis, Oxford Brookes University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.249406.

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40

Kim, Yoonkee. "Surface acoustic wave propagation in multilayered and multichannel waveguide structures." Diss., Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/15060.

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41

Rostad, Torbjørn. "Optical Detection of Surface Acoustic Waves." Thesis, Norwegian University of Science and Technology, Department of Electronics and Telecommunications, 2006. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-9487.

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Abstract:

This project was worked on during the autumn 2005 at the Norwegian University of Science and Technology, Department of Electronics and Telecommunications. The assignment was to write a new LabVIEW programme that is to run the measurement procedure of a laser probe setup. The setup is used in characterization of surface acoustic waves(SAW). A programme was written that contained the necessary functionality and proved to operate satisfactorily. Several measurements were made on a SAW transducer, accurately picturing the wave. Fourier analysis were performed on the collected data in order to separate the propagation directions. An absolute amplitude measurement was made on a heterodyne interferometer, and the result was compared to a similar scan made using the laser probe. The work shows that the setup is ready for calibration against the heterodyne interferometer, in order to enable the laser probe to measure absolute amplitude by itself.

42

Mutti, Paolo. "Surface acoustic waves for semiconductor characterization." Thesis, University of Oxford, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.357598.

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43

Harvey, Alan Paul. "Nonlinear surface acoustic waves and applications." Thesis, University of Southampton, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.255827.

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44

Furnell, G. D. "A study of acoustic wave propagation within curved ducting systems /." Title page, table of contents and abstract only, 1989. http://web4.library.adelaide.edu.au/theses/09PH/09phf987.pdf.

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45

Terrill, Eric J. "Acoustic measurements of air entrainment by breaking waves /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 1998. http://wwwlib.umi.com/cr/ucsd/fullcit?p9907829.

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46

Nash, Geoffrey Richard. "Surface acoustic wave investigations of low dimensional electron systems." Thesis, University of Bath, 1996. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.320474.

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47

Beaucage, Timothy Ray. "High Temperature LGT Expansion Measurements through Multiple Techniques." Fogler Library, University of Maine, 2007. http://www.library.umaine.edu/theses/pdf/BeaucageTR2007.pdf.

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48

Cameron, Thomas P. (Thomas Philip) Carleton University Dissertation Engineering Electrical. "Circuit factor compensation for saw filters using modal analysis." Ottawa, 1988.

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49

Berry, David Leonard. "Acoustic scattering by near-surface inhomogeneities in porous media." Thesis, Open University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.254021.

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50

Swacek, Christian Bernhard. "Optical generation of tone-burst Rayleigh surface waves for nonlinear ultrasonic measurements." Thesis, Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/45812.

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Abstract:

Conventional contact ultrasonic methods suffer from large variability, which is known to originate from a number of sources such as coupling variability, and the surface roughness at the transducer/specimen interface. The inherently small higherharmonic signals can be significantly influenced by the changes in contact conditions, especially in nonlinear ultrasonic measurements. For this reason, the noncontact generation and detection techniques are very attractive. This research first focuses on the optical generation of tone-burst surface acoustic waves in a metallic specimen. Two methods that use laser light as an optical source are compared for generating surface acoustics waves in the 5 MHz range. Both the shadow mask and diffraction grating are used to convert a laser pulse to a tone-burst signal pattern on the specimen. The generated signals are detected by a wedge transducer at a fixed location and then the harmonic contents in the generated signals and the repeatability of the methods are evaluated. Finally, the developed method is used to characterize the material nonlinearity of aluminum (Al 6061) and steel (A36). The results showed repeatable measurements for ablative signal excitation on aluminum.