Engineering Commons^™

Nanoplasmonic Sensors Based On Periodic Arrays Of Gold Nanoparticles, Hao Jiang

Electronic Thesis and Dissertation Repository

Nanoplasmonic sensors use the localized surface plasmon resonance (LSPR) of metal nanostructures to sense the refractive index change in a surface-bound layer caused by biomolecular interactions or changing chemical environment. In this thesis, four types of sensor configurations based on gold nanoparticle arrays are thoroughly investigated.

The first configuration is a periodic array of gold nanoparticles excited by the evanescent field of an optical waveguide mode. Since light carried by a waveguide mode propagates along the same plane of the periodicities, the coupling of nanoparticles are strongly affected by the photonic crystal lattice. This configuration is investigated both in simulations …

Design Of Wireless Power Transfer And Data Telemetry System For Biomedical Applications, Ashraf Bin Islam

Doctoral Dissertations

With the advancement of biomedical instrumentation technologies sensor based remote healthcare monitoring system is gaining more attention day by day. In this system wearable and implantable sensors are placed outside or inside of the human body. Certain sensors are needed to be placed inside the human body to acquire the information on the vital physiological phenomena such as glucose, lactate, pH, oxygen, etc. These implantable sensors have associated circuits for sensor signal processing and data transmission. Powering the circuit is always a crucial design issue. Batteries cannot be used in implantable sensors which can come in contact with the blood …

Analytical Analysis Of Second-Order Stokes Wave In Brillouin Ring Fiber Laser, Faisal Rafiq Mahamd Adikan

Faisal Rafiq Mahamd Adikan

This paper details a theoretical modeling of Brillouin ring fiber laser which incorporates the interaction between multiple Brillouin Stokes signals. The ring cavity was pumped at several Brillouin pump (BP) powers and the output was measured through an optical coupler with various coupling ratios. The first-order Brillouin Stokes signal was saturated with the presence of the second-order Stokes signal in the cavity as a result of energy transfer between them. The outcome of the study found that the optimum point for the first-order Stokes wave performance is at laser power reduction of 10%. Resultantly, at the optimum output coupling ratio …

Light Coupling Between A Singlemode-Multimode-Singlemode (Sms) Fiber Structure And A Long Period Fiber Gating, Qiang Wu, Yuliya Semenova, Youqiao Ma, Pengfei Wang, Tuan Gao, Long Jin, Gerald Farrell

Articles

We propose a novel optical coupling technique based on evanescent field coupling between a singlemode-multimode-singlemode (SMS) fiber structure and a long period fiber grating (LPFG). By parallel placement of the two fiber sections in close proximity to each other, the excited multi-cladding modes from the SMS fiber section can be selectively coupled to the guided mode in the LPFG, and vice versa. A theoretical analysis based for such a structure is undertaken and the simulated results are verified by experiments demonstrating a maximum coupling efficiency of up to 1.66% (which could be improved to 27.5% in theory) over a broadband …

Short Distance Ground Wave Propagation Modeling In Irregular And Forested Environments, Zachary Michael Crane

Masters Theses

A model for the phase of a ground wave propagating over irregular and forested terrain has been developed and tested for a transmission system operating at 3.315 MHz.

In this model, the time delay induced beyond that of the standard velocity of radio waves in air is modeled as a combination of 3 effects: the finite conductivity of the earth, the irregularity of the terrain over which the wave is propagating, and the forestation of the terrain.

The finite conductivity model is based on a small curvature formula developed by Van Der Pol and Bremmer. The terrain irregularity model models …

In-Situ Ellipsometry Characterization Of Anodically Grown Silicon Dioxide And Lithium Intercalation Into Silicon, Eric A. Montgomery

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

In this thesis, in-situ ellipsometry and electroanalytical investigations of two electrochemical processes are reported: including the formation of anodically grown silicon dioxide and the intercalation of lithium into silicon. Analysis of the ellipsometry data shows that the anodically grown silicon dioxide layer is uniform and has similar properties as thermally grown silicon dioxide. The lithium-ion intercalation data reveals non-uniform thin film formation, which requires further studies and development of appropriate ellipsometric optical models.

Advisers: Eva Schubert and Mathias Schubert

Thermodynamic Limit To Photonic-Plasmonic Light-Trapping In Thin Films On Metals, Eric A. Schiff

Physics - All Scholarship

We calculate the maximum optical absorptance enhancements in thin semiconductor films on metals due to structures that diffuse light and couple it to surface plasmon polaritons. The calculations can be used to estimate plasmonic effects on light-trapping in solar cells. The calculations are based on the statistical distribution of energy in the electromagnetic modes of the structure, which include surface plasmon polariton modes at the metal interface as well as the trapped waveguide modes in the film. The enhancement has the form 4n²+nλ/h (n – film refractive index, λ – optical wavelength, h …

Liquid Crystal Devices For Optical Communications And Sensing Applications, Sunish Mathews

Doctoral

This thesis is focussed on the design and development of liquid crystal based tunable photonic devices for applications in optical communications and optical sensing, with an emphasis on all-fiber device configuration. The infiltration of liquid crystals into photonic crystal fiber provides a suitable common platform to design and fabricate simple and compact all-fiber tunable photonic devices which can be easily integrated with optical fiber networks and sensing systems. Based on the infiltration of liquid crystals – materials with high dielectric anisotropy, into photonic crystal fibers a common platform is developed to address the need for electronically tunable photonic devices with …

Dual-Phase Sensing For Early Detection Of Prepreg Structural Failures Via Etched Cladding Bragg Grating, Faisal Rafiq Mahamd Adikan

Faisal Rafiq Mahamd Adikan

A dual-phase optical fiber-based sensor for early detection against prepreg structural failures is proposed and successfully demonstrated. The sensor consists of an etched fiber Bragg grating (FBG) mounted onto an aluminium plate. The sensor is tested using a simple pressure and petrochemical test rig. By observing the shift of the reflected wavelength of the FBG sensor we can simultaneously detect two parameters: (i) pressure and (ii) petrochemical. The experimental results show the potential of using the FBG sensor for early detection of submarine oil pipe leaking. (C) 2011 Elsevier B.V. All rights reserved.

Wavelength Dependence Of Transverse Mode Coupling With/Without E-Block Of Gan Laser Cavity, Krishneel Lal

Electrical Engineering

No abstract provided.

Giant Magnetostriction In Annealed Co1-XFeX Thin-Films, Dwight Hunter, Will Osborn, Ke Wang, Nataliya Kazantseva, Jason R. Hattrick-Simpers, Richard Suchoski, Ryota Takahashi, Marcus L. Young, Apurva Mehta, Leonid A. Bendersky, Same E. Lofland, Manfred Wuttig, Ichiro Takeuchi

Faculty Publications

Chemical and structural heterogeneity and the resulting interaction of coexisting phases can lead to extraordinary behaviours in oxides, as observed in piezoelectric materials at morphotropic phase boundaries and relaxor ferroelectrics. However, such phenomena are rare in metallic alloys. Here we show that, by tuning the presence of structural heterogeneity in textured Co_1−xFe_x thin films, effective magnetostriction λeff as large as 260 p.p.m. can be achieved at low-saturation field of ~10 mT. Assuming λ100 is the dominant component, this number translates to an upper limit of magnetostriction ofλ100≈5λeff >1,000 p.p.m. Microstructural analyses …

Analytical Study Of Nonlinear Phase Shift Through Stimulated Brillouin Scattering In Single Mode Fiber With The Pump Power Recycling Technique, Faisal Rafiq Mahamd Adikan

Faisal Rafiq Mahamd Adikan

We present a theoretical study of nonlinear phase shift through stimulated Brillouin scattering in single mode optical fiber. Analytical expressions describing the nonlinear phase shift for the pump and Stokes waves in the pump power recycling technique have been derived. The dependence of the nonlinear phase shift on the optical fiber length, the reflectivity of the optical mirror and the frequency detuning coefficient have been analyzed for different input pump power values. We found that with the recycling pump technique, the nonlinear phase shift due to stimulated Brillouin scattering reduced to less than 0.1 rad for 5 km optical fiber …

Fabricate An 8.35-Ghz Frequency Synthesizer, A. Attaran, Hossein Ameri Mahabadi, M. Moghavvemi

Hossein Ameri Mahabadi

The article presents information on designing a low-noise frequency synthesizer for achieving low-phase-noise outputs past 8 GHz for digital microwave radios (DMRs). These synthesizers can be used with the DMRs, depending on advanced digital modulation such as quadrature-amplitude-modulation (QAM) and quadrature-phase-shift-keying (QPSK) formats.

Led Street Light Research Project, Donald K. Carter, Stephen Quick

Stephen Quick

The City of Pittsburgh planned to replace its existing 40,000 street lighting fixtures with LED fixtures and engaged the Remaking Cities Institute (RCI) to investigate the full range of potential benefits of a replacement program in business districts. The study team investigated the technological potentials offered by LED lighting, best management practices (BMP) in LED lighting and lessons learned from cities where LED lighting has been installed, as well as the place-making and aesthetic impact of LED lighting and associated technologies. The team also investigated issues raised by the use of LEDs as the light source and issues of replacing …

A Microfiber Cavity With Minimal-Volume Confinement, Ming Ding, Pengfei Wang, Timothy Lee, Gilberto Brambilla

Articles

We demonstrate a type of microcavity with minimal-volume confinement using a high-contrast phase-shifted Bragg grating in a microfiber. While waveguiding by the air-silica boundary provides a diffraction-limited two-dimensional confinement, the grating introduces the third degree of confinement. Theoretical simulations verified the microfiber cavity confinement while the experimental demonstration, carried out in samples nanostructured by focused ion beam, showed a good agreement with theoretical predictions. This cavity can be used for a variety of applications ranging from sensing to quantum dynamic experiments.

Chaotic Bandgaps In Hybrid Acousto-Optic Feedback And Their Implications, Monish Ranjan Chatterjee, Mohammed A. Al-Saedi

Electrical and Computer Engineering Faculty Publications

The nonlinear dynamics of a hybrid acousto-optic device was examined from the perspective of the Lyapunov exponent (LE) and bifurcation maps. The plots for LE versus system parameters and bifurcation maps have recently been examined against known simulation results including chaotic encryption experiments [1]. It is verified that the "loop gain" (feedback gain (β) times incident light amplitude (Iin) needs to be greater than one as a necessary , but not sufficient condition for the onset of chaos.

It is found that for certain combinations of β, Iin, net bias voltage (αtοt), and the initial value of the first-order scattered …

902–928mhz Uhf Rfid Tag Antenna Design, Fabrication And Test, Chiweng Kam

Master's Theses

Radio Frequency Identification (RFID) uses RF radiation to identify physical objects. With decreasing integrated circuit (IC) cost and size, RFID applications are becoming economically feasible and gaining popularity. Researchers at MIT suggest that RFID tags operating in the 900 MHz band (ultrahigh frequency, UHF) represent the best compromise of cost, read range, and capabilities [1]. Passive RFID tags, which exclude radio transmitters and internal power sources, are popular due to their small size and low cost [1].

This project produced Cal Poly’s first ever on-campus printed, assembled, and operational UHF (902 to 928 MHz) passive RFID tag. Project goals include …

Fem-Fct Based Dynamic Simulation Of Trichel Pulse Corona Discharge In Point-Plane Configuration, Paria Sattari

Electronic Thesis and Dissertation Repository

In this thesis, a new two-dimensional numerical solver is presented for the dynamic simulation of the Trichel pulse regime of negative corona discharge in point-plane configuration. The goal of this thesis is to simulate the corona discharge phenomenon and to improve the existing models so that the results have an acceptable compatibility with the experimentally obtained data. The numerical technique used in this thesis is a combination of Finite Element Method (FEM) and Flux Corrected Transport (FCT). These techniques are proved to be the best techniques, presented so far for solving the nonlinear hyperbolic equations that simulate corona discharge phenomenon. …

Exposing To Emf, Mahmoud Moghavvemi, Farhang Alijani, Hossein Ameri Mahabadi, Maryami Ashayer Soltan

Hossein Ameri Mahabadi

No abstract provided.

Optical Power Splitting Techniques Using Photonic Crystal Line Defect Waveguides, Rajat Dey

Electronic Thesis and Dissertation Repository

“Photonic Crystals (PCs)” are dielectric or metallo-dielectric structures with periodic spatial alternations of refractive index on the scale of the wavelength of light. Many optical devices, based on PCs, have been proposed. There are multiple ways by which equal amount of power of incoming signals can be divided into two, three and four output channels; for example using multiple coupled photonic crystal waveguides, directional coupling and cascaded multimode PC waveguides. Ideally, the splitter should divide the input power equally into the output channels without significant reflection or radiation losses and should be compact in size. In this thesis we have …

Planar Photonic Crystal For Biosensor Applications, Anil Kumar Mudraboyina

Electronic Thesis and Dissertation Repository

Photonic crystals are the subject of intense study due to their capability to provide precise control of optical transmission characteristics through the choice of their periodic lattice parameters and the material with which they are fabricated. The sensitivity of photonic crystal band structure and defect transmission states to refractive index changes either at planar boundaries of a 2-D crystal or at individual lattice sites, make these structures potentially attractive for integrated point detection biosensor devices.

1-D Photonic crystal (PC) and 2-D PC based sensors were developed and studied in terms of sensitivity with different types materials functionalized on the surface. …

Comparison Of A High Purity Germanium Gamma Ray Spectrometer And A Multidimensional Nai(T1) Scintillation Gamma Ray Spectrometer, Greg Stratton

Aerospace Engineering

This report compares two different gamma ray spectrometers in terms of performance, operation, and apparatus and also investigates the design and integration challenges of using gamma ray spectrometers in space. The first spectrometer is a one-dimensional high purity germanium (HPGe) spectrometer and the second is a multidimensional NaI(Tl) scintillation spectrometer (MGRS). The key results show that the HPGe exhibits 15 to 27 times better energy resolution than the MGRS, but the MGRS is 52 times more sensitive and removes 177 % more of the background radiation.

Assembly Of Low Phase Noise Sub-Millimeter Wave Local Oscillator In Ku Band Frequency, M. Moghavvemi, Hossein Ameri Mahabadi, A. Attaran

Hossein Ameri Mahabadi

A design and fabrication of a dual-band synthesizer device is presented in this paper. The noise analysis in synthesizer loop block component is modeled individually. The Design methodology is elaborated along with the test results. The initial frequency synthesizer in 1.8-2.4GHz frequency range (L and S-band) is designed and it is multiplied by 8. Microstrip bandpass filters (LFCN) are used to filter out the spurious frequency contents; the final output frequency is 14-20GHz (Ku-band). Phase noise investigation, design steps, filter assembling of 14-20GHz synthesizer is presented in this paper.

Novel Client Booking System In Klcc Twin Tower Bridge, Hossein Ameri Mahabadi, R. Ameri

Hossein Ameri Mahabadi

This system should help managing the visitors and tour guides as well as scheduling tours to visit “Petronas Twin Towers Sky Bridge”. The system should at least support the following characteristics. It should keep track of visitors and or tourists. It should keep information about tour guides and their working hour and other related information about such employees. The administrators should be able to schedule their visiting hours. This is a work-flow system and it need to keep track of daily visitors. The requirement was meant for this system is straight forward and very clear with so little complexity. On …

A Compact Analytical Design Of Dual-Loop 18 Ghz Frequency Synthesizer To Enhance Signal Reliability In Digital Millimeter Radio Link System, M. Moghavvemi, Hossein Ameri Mahabadi, A. Attaran

Hossein Ameri Mahabadi

In this paper a high resolution dual-loop 17.7–19.7 GHz frequency synthesizer is presented which is compatible with ITU-R (F.595-6) standards. The investigations of phase noise and spur frequency contents are discussed in detail. The simulated and measured phase noise and spur frequency contents are similar to one another. Phase noise of –81 dBc/Hz in 17.7 GHz at 10 KHz offset frequency is measured by (HP8560) series Spectrum analyzer and it matches with predicted measurements.

A Simple Ultrasensitive Displacement Sensor Based On A High Bend Loss Single-Mode Fibre And A Ratiometric Measurement System, Pengfei Wang, Gilberto Brambilla, Yuliya Semenova, Qiang Wu, Gerald Farrell

Articles

An all-fibre displacement sensor with a simple configuration and capable of monitoring sub-50 nm displacements is proposed and investigated experimentally. The proposed fibre displacement sensor consists of a half-loop structure of bare high bend loss single-mode fibre 1060XP and a ratiometric power interrogation system. By measuring the change in transmission ratio in the ratiometric system, a change in displacement can be measured. The displacement sensor is sensitive to temperature and an experimental investigation of this sensitivity is presented. It is found that the peak shift response has a linear variation with temperature; therefore, temperature dependence can be mitigated by a …

Resonance Damping In Ferromagnets And Ferroelectrics, Allan Widom, Somu Sivasubramanian, Carmine Vittoria, S. Yoon, Yogendra N. Srivastava

Carmine Vittoria

The phenomenological equations of motion for the relaxation of ordered phases of magnetized and polarized crystal phases can be developed in close analogy with one another. For the case of magnetized systems, the driving magnetic field intensity toward relaxation was developed by Gilbert. For the case of polarized systems, the driving electric field intensity toward relaxation was developed by Khalatnikov. The transport times for relaxation into thermal equilibrium can be attributed to viscous sound wave damping via magnetostriction for the magnetic case and electrostriction for the polarization case.

Resonance Damping In Ferromagnets And Ferroelectrics, Allan Widom, Somu Sivasubramanian, Carmine Vittoria, S. Yoon, Yogendra N. Srivastava

Allan Widom

The phenomenological equations of motion for the relaxation of ordered phases of magnetized and polarized crystal phases can be developed in close analogy with one another. For the case of magnetized systems, the driving magnetic field intensity toward relaxation was developed by Gilbert. For the case of polarized systems, the driving electric field intensity toward relaxation was developed by Khalatnikov. The transport times for relaxation into thermal equilibrium can be attributed to viscous sound wave damping via magnetostriction for the magnetic case and electrostriction for the polarization case.

Design, Fabrication, And Testing Of An Electromagnetic Rail Gun For The Repeated Testing And Simulation Of Orbital Debris Impacts, Jeff Maniglia, Jordan Smiroldo, Alex Westfall, Guy Zohar

Aerospace Engineering

An Electromagnetic Railgun (EMRG) was designed, built, and tested, capable of firing a projectile a 1 gram projectile at 650 m/s muzzle velocity. The EMRG utilizes an injector, a high voltage power supply, a capacitor bank, inductors and rails. The injector fires 2300 psig Nitrogen gas into the system to provide an initial velocity. The high voltage power supply charges the capacitor bank. The capacitor bank discharges the electric potential built up through the projectile while inside the rails in order to create the EMRG’s force. The inductors are used to pulse form the capacitor bank in order to get …

Rfid Techniques For Passive Electronics, Ryan Behr, David Cobos

Electrical Engineering

No abstract provided.