Electromagnetics and Photonics Commons^™

A Thermally Wavelength-Tunable Photonic Switch Based On Silicon Microring Resonator, Xuan Wang

FIU Electronic Theses and Dissertations

Silicon photonics is a very promising technology for future low-cost high-bandwidth optical telecommunication applications down to the chip level. This is due to the high degree of integration, high optical bandwidth and large speed coupled with the development of a wide range of integrated optical functions. Silicon-based microring resonators are a key building block that can be used to realize many optical functions such as switching, multiplexing, demultiplaxing and detection of optical wave. The ability to tune the resonances of the microring resonators is highly desirable in many of their applications. In this work, the study and application of a …

Effective Reconfigurable Antenna Designs To Enhance Performance And Enable Wireless Powering, Shishir S. Punjala

FIU Electronic Theses and Dissertations

With the increase in traffic on the internet, there is a greater demand for wireless mobile and ubiquitous applications. These applications need antennas that are not only broadband, but can also work in different frequency spectrums. Even though there is a greater demand for such applications, it is still imperative to conserve power. Thus, there is a need to design multi-broadband antennas that do not use a lot of power. Reconfigurable antennas can work in different frequency spectrums as well as conserve power. The current designs of reconfigurable antennas work only in one band. There is a need to design …

Influence Of Solar Heating On The Performance Of Integrated Solar Cell Microstrip Patch Antennas, Maria Roo Ons, S. Shynu, M Seredynski, Max Ammann, Sarah Mccormack, Brian Norton

Articles

The integration of microstrip patch antennas with photovoltaics has been proposed for applications in autonomous wireless communication systems located on building façades. Full integration was achieved using polycrystalline silicon solar cells as both antenna ground plane and direct current power generation in the same device. An overview of the proposed photovoltaic antenna designs is provided and the variation characterised of the electromagnetic properties of the device with temperature and solar radiation. Measurements for both copper and solar antennas are reported on three different commercial laminates with contrasting values for thermal coefficient of the dielectric constant.

Directional Dual-Band Slot Antenna With Dual-Bandgap High-Impedance-Surface Reflector, Xiulong Bao, Giuseppe Ruvio, Max Ammann

Articles

A compact dual-band high-impedance-surface EBG structure is employed as a reflector for a dual-band annular-slot antenna. The reflector comprises an array of miniaturized EBG cells which utilizes square patches augmented by four S-shaped corrugated arms to reduce the resonant frequency of the proposed EBG structure. In order to broaden the bandwidth and adjust the frequency ratio for the dual-band EBG structure, a log-periodic spacing between the S-shaped strips is introduced. The combination of microstrip-fed annular slot and EBG reflector provides directional properties for both frequency bands with reduced size and low-profile.

Design Of Acousto-Optic Chaos Based Secure Free-Space Optical Communication Links, Anjan K. Ghosh, Pramode K. Verma, Samuel Cheng, Robert C. Huck, Monish Ranjan Chatterjee, Mohammed A. Al-Saedi

Electrical and Computer Engineering Faculty Publications

We discuss the design of an acousto-optic cell based free space optical communication link where the data beam is made secure through chaos encryption. Using external signal modulation of the diffracted light from a hybrid acousto-optic cell chaos (or directly via incorporation in the sound-cell driver's bias voltage) encryption of data is possible. We have shown numerically that decryption of the encoded data is possible by using an identical acousto-optic system in the receiver.

Nondestructive Electromagnetic Material Characterization Using A Dual Waveguide Probe: A Full Wave Solution, Milo W. Hyde Iv, James W. Stewart, Michael J. Havrilla, William P. Baker, Edward Rothwell, Dennis P. Nyquist

Faculty Publications

A nondestructive technique for determining the complex permittivity and permeability of a perfect electric conductor backed magnetic shielding material using a dual waveguide probe is presented. The dual waveguide probe allows for the simultaneous collection of reflection and transmission coefficients which distinguishes it from single probe methods common in the literature. Theoretical development of these coefficients, which is accomplished through a coupled magnetic field integral equations formulation using Love's equivalence principle and solved via the method of moments (MOM), is discussed. Evaluation of the resulting MOM impedance matrix elements is performed using complex plane integration leading to enhanced computational efficiency …

Design And Development Of A Ka-Band Interferometer For Cryospheric Applications, Harish K. Vedantham

Masters Theses 1911 - February 2014

Topographic maps of the earth are essential to geographic and earth science studies. In particular, mapping and estimating physical parameters of the earth’s water and ice cover are critical to global climate studies. Among these, snow, ocean and fresh water topography, snow wetness and water equivalent are of immediate interest to the scientific community.

Challenges in the instrument development and deployment posed by these required measurements are twofold. Firstly, these measurements are required to have global coverage, yet maintain stringent spatial resolution and accuracy margins. Secondly, snow topography measurement requires minimal electromagnetic wave penetration through snow, hence requiring the use …

Digital Camera Photographing In Measuring Propagation Loss Properties Of Ion2exchange Planar Optical Waveguides, Ling-Hua Jia, Feng Qiu, Jian Ying, Ti Yun-Jiang, Jie Z|Heng, Pengfei Wang, Gerald Farrell

Articles

The digital photographs of propagation lines of ion-exchange planar glass optical waveguides were taken by a common digital camera.According to the profile of light intensity of propagation lines,the attenuation curves were fitted and the propagation losses of the waveguides were calculated.The waveguides were treated by annealing process,and propagation losses properties were studied before and after annealing,respectively.The results show that the loss of waveguide increases with the mode.The loss in 0 mode decreases from 2.148 9 dB·cm－1 to 0.746 0 dB·cm－1.

Model For Alumina Nanopore-Based Optical Filter, Nathan Lehman, Rama Venkat, Robert A. Schill

Electrical & Computer Engineering Faculty Research

Alumina nanopore structures find applications in magnetic sensors, optical filters, and various biological devices. In this work, we present a ray-optics model for the optical filter. We present a detailed simulation and a simplified analytical expression for the reflectance as a function of the alumina parameters such as pore diameter, pore density, alumina thickness, and a function of the wavelength and angle of incidence of the illuminating plane electromagnetic wave. The reflectance vs wavelength in the range of 400–800nm obtained from the simulation and the analytical expression are compared with that of the experiments for thin and thick alumina. All …

Zero-Broadening Measurement In Brillouin Based Slow-Light Delays, Andrzej Wiatrek, Ronny Henker, Stefan Preußler, Max Ammann, Andreas Schwarzbacher, Thomas Schneider

Articles

A novel method for the achievement of zero-broadening in a SBS based slow-light system is discussed in theory and demonstrated experimentally. The system is realized just with a single broadened Brillouin gain. It is shown, that if the gain bandwidth is much broader than the initial pulse width, the output pulse width decreases with increasing pump power. A compression of approximately 90 % of the initial pulse width was achieved in simulation and experiment.

Feynman’S Relativistic Electrodynamics Paradox And The Aharonov-Bohm Effect, Adam Caprez, Herman Batelaan

Department of Physics and Astronomy: Faculty Publications

An analysis is done of a relativistic paradox posed in the Feynman Lectures of Physics involving two interacting charges. The physical system presented is compared with similar systems that also lead to relativistic paradoxes. The momentum conservation problem for these systems is presented. The relation between the presented analysis and the ongoing debates on momentum conservation in the Aharonov-Bohm problem is discussed.

Monoclinic Optical Constants, Birefringence, And Dichroism Of Slanted Titanium Nanocolumns Determined By Generalized Ellipsometry, Daniel Schmidt, Benjamin Booso, Tino Hofmann, Eva Schubert, Andrew Sarangan, Mathias Schubert

Electrical and Computer Engineering Faculty Publications

Generalized spectroscopic ellipsometry determines the principal monoclinic optical constants of thin films consisting of slanted titanium nanocolumns deposited by glancing angle deposition under 85° incidence and tilted from the surface normal by 47°. Form birefringence measured for wavelengths from 500 to 1000 nm renders the Ti nanocolumns monoclinic absorbing crystals with c-axis along the nanocolumns, b-axis parallel to the film interface, and 67.5° monoclinic angle between the aand c-axes. The columnar thin film reveals anomalous optical dispersion, extreme birefringence, strong dichroism, and differs completely from bulk titanium. Characteristic bulk interband transitions are absent in the spectral range investigated.

Analysis Of Possible Use Of Identification Technologies In Disassembly, Vukica Jovanović, Sreten Filipović, Gordana Ostojić, Stevan Stankovski, Milovan Lazarević

Engineering Technology Faculty Publications

The barcodes and Radio Frequency Identification tags that are being used during manufacturing, assembly, warehousing, and distribution could also be reused at the end of the product lifecycle for an identification of the correct disassembly process that would result in recycling of its components. The barcodes or RFID tags can be helpful in identifying objects in terms of sustainable development, regarding disassembly, recycling and reuse. In this paper, the analysis of the current applications of RFID Technology in the final phase of the product lifecycle will be presented. The simulation of the disassembly process supported by both barcode and RFID-enabled …

The Effect Of Copt Crystallinity And Grain Texturing On Properties Of Exchange-Coupled Fe/Copt Systems, H. Oguchi, A. Zambano, M. Yu, Jason R. Hattrick-Simpers, D. Banerjee, Y. Liu, Z. L. Wang, J. P. Liu, S. E. Lofland, D. Josell, I. Takeuchi

Faculty Publications

The effect of the crystallinity and the grain texturing of CoPt hard layers on exchange coupled Fe/CoPt soft/hard magnetic systems was studied using gradient thickness multilayer thin films. We have studied the hard layer structures by transmission electron microscopy and x-ray diffraction, and characterized the exchange coupling interaction through magnetization loops obtained by the magneto-optical Kerr effect measurement. We found that exchange coupling strongly depends on the crystalline characteristics of the CoPt hard layer. There is correlation between the mixture of different grain orientations of the CoPt hard layer and coupling efficiency. In particular, interlayer coupling is enhanced when there …