With the growth of wireless communications, comes the need for engineers knowledgeable in 3D electromagnetic (EM) simulation of high-frequency circuits. To give electrical engineering students a better understanding of the behavior of electromagnetic fields, experiments including the use of 3D EM simulation software were proposed. Most students get lost in differential equations, curls, and divergences; this thesis aims to remedy that by exposing them to 3D EM simulation, which may motivate them toward further study in electromagnetics. Also, experience using EMPro is very beneficial for future RF/microwave/antenna engineers, as use of 3D EM simulation is becoming a requirement for this field. 3D EM simulators solve problems where using classical analysis techniques is impractical. Classical EM solutions to simple objects such as boxes, cylinders, and spheres, are widely known; but when the object is more complex, numerical approaches are preferred for their speed. Currently, Cal Poly does not use 3D electromagnetic simulation in any of its courses. Targeted relevant courses include EE 335/375: EM Fields & Transmission Lines, EE 402: EM Waves, EE 405/445: High-Frequency Amplifier Design, EE 425/455: Analog Filter Design, EE 502: Microwave Engineering, and EE 533: Antennas. As a starting point, EE 425/455 was targeted. In choosing which filters to investigate, simplicity and cost were the most important factors. For simplicity, transverse electromagnetic (TEM) mode filters were chosen; also, using a trough design for these filters would allow for simple construction and access. Also, a circular waveguide filter was chosen as an alternative to the TEM filters, as the modes are either transverse electric or transverse magnetic. To lower costs, printed circuit board was used to construct the filters, along with brass tubing, semi-rigid coaxial cable, and copper plumbing caps. From these guidelines, three electronic bandpass filter experiments were investigated: a 1 GHz half-wave coaxial resonator filter, a 2 GHz copper end cap filter, and a tunable 1 GHz quarter-wave coaxial resonator filter. Electric and magnetic field coupling was used to excite the filters. They were then simulated using finite difference time domain (FDTD) simulations in Agilent EMPro. From the simulations, tradeoffs between insertion loss and bandwidth were observed. After, the filters were built and measured using a network analyzer. The quarter-wave filter was incorporated in Cal Poly’s EE 455 course during spring 2012. Students completed an EMPro tutorial, simulated the filters, and measured them using network analyzers. Student feedback was mixed, and modifications were made for future implementations.

Microwave interferometry (MI) is a Doppler based diagnostic tool used to measure the detonation velocity of explosives, which has applications to explosive safety. The geometry used in existing MI experiments is cylindrical explosives pellets layered in a cylindrical case. It is of interest to Lawrence Livermore National Labs to measure additional geometries that may be overmoded, meaning that the geometries propagate higher-order transverse electromagnetic waves. The goal of my project is to measure and analyze the input reflection from a novel structure and to find a good frequency to use in an experiment using this structure. Two methods of determining a good frequency are applied to the phase of the input reflection. The first method is R2, used to measure the linearity of input reflection phase. The second is a zero-crossing method that measures how periodic the input reflection phase is. Frequencies with R2 values higher than .995 may be usable for an experiment in the novel structure.

High-power debris-free vacuum ultraviolet (VUV) light sources have applications in several scientific and engineering areas, such as high volume manufacturing lithography and inspection tools in the semiconductor industry, as well as other applications in material processing and photochemistry. For the past decades, the semiconductor industry has been driven by what is called "Moore's Law". The entire semiconductor industry relies on this rule, which requires chip makers to pack transistors more tightly with every new generation of chips, shrinking the size of transistors. The ability to solve roadmap challenges is, at least partly, proportional to our ability to measure them. The focus of this thesis is on imaging transient VUV laser plasma sources with specialized reflective imaging optics for metrology applications. The plasma dynamics in novel laser-based Zinc and Tin plasma sources will be discussed. The Schwarzschild optical system was installed to investigate the time evolution of the plasma size in the VUV region at wavelengths of 172 nm and 194 nm. The outcomes are valuable for interpreting the dynamics of low-temperature plasma and to optimize laser-based VUV light sources.

Dynamics occurring on microscopic scales, such as electronic motion inside atoms and molecules, are governed by quantum mechanics. However, the Schroedinger equation is usually too complicated to solve analytically for systems other than the hydrogen atom. Even for some simple atoms such as helium, it still takes months to do a full numerical analysis. Therefore, practical problems are often solved only after simplification. The results are then compared with the experimental outcome in both the spectral and temporal domain. For accurate experimental comparison, temporal resolution on the attosecond scale is required. This had not been achieved until the first demonstration of the single attosecond pulse in 2001. After this breakthrough, "attophysics" immediately became a hot field in the physics and optics community. While the attosecond pulse has served as an irreplaceable tool in many fundamental research studies of ultrafast dynamics, the pulse generation process itself is an interesting topic in the ultrafast field. When an intense femtosecond laser is tightly focused on a gaseous target, electrons inside the neutral atoms are ripped away through tunneling ionization. Under certain circumstances, the electrons are able to reunite with the parent ions and release photon bursts lasting only tens to hundreds of attoseconds. This process repeats itself every half cycle of the driving pulse, generating a train of single attosecond pulses which lasts longer than one femtosecond. To achieve true temporal resolution on the attosecond time scale, single isolated attosecond pulses are required, meaning only one attosecond pulse can be produced per driving pulse. Up to now, there are only a few methods which have been demonstrated experimentally to generate isolated attosecond pulses. Pioneering work generated single attosecond pulse using a carrier-envelope phase-stabilized 3.3 fs laser pulse, which is out of reach for most research groups. An alternative method termed as polarization gating generated single attosecond pulses with 5 fs driving pulses, which is still difficult to achieve experimentally. Most recently, a new technique termed as Double Optical Gating (DOG) was developed in our group to allow the generation of single attosecond pulse with longer driving pulse durations. For example, isolated 150 as pulses were demonstrated with a 25 fs driving laser directly from a commercially-available Ti:Sapphire amplifier. Isolated attosecond pulses as short as 107 as have been demonstrated with the DOG scheme before this work. Here, we employ this method to shorten the pulse duration even further, demonstrating world-record isolated 67 as pulses. Optical pulses with attosecond duration are the shortest controllable process up to now and are much faster than the electron response times in any electronic devices. In consequence, it is also a challenge to characterize attosecond pulses experimentally, especially when they feature a broadband spectrum. Similar challenges have previously been met in characterizing femtosecond laser pulses, with many schemes already proposed and well-demonstrated experimentally. Similar schemes can be applied in characterizing attosecond pulses with narrow bandwidth. The limitation of these techniques is presented here, and a method recently developed to overcome those limitations is discussed. At last, several experimental advances toward the characterization of the isolated 25 as pulses, which is one atomic unit time, are discussed briefly.

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The path towards realizing next-generation petascale and exascale computing is increasingly dependent on building supercomputers with unprecedented numbers of processors. Given the rise of multicore processors, the number of network endpoints both on-chip and off-chip is growing exponentially, with systems in 2018 anticipated to contain thousands of processing elements on-chip and billions of processing elements system-wide. To prevent the interconnect from dominating the overall cost of future systems, there is a critical need for scalable interconnects that capture the communication requirements of target ultrascale applications. It is therefore essential to understand high-end application communication characteristics across a broad spectrum of computational methods, and utilize that insight to tailor interconnect designs to the specific requirements of the underlying codes. This work makes several unique contributions towards attaining that goal. First, the communication traces for a number of high-end application communication requirements, whose computational methods include: finite-difference, lattice-Boltzmann, particle-in-cell, sparse linear algebra, particle mesh ewald, and FFT-based solvers. This thesis presents an introduction to the fit-tree approach for designing network infrastructure that is tailored to application requirements. A fit-tree minimizes the component count of an interconnect without impacting application performance compared to a fully connected network. The last section introduces a methodology for reconfigurable networks to implement fit-tree solutions called Hybrid Flexibly Assignable Switch Topology (HFAST). HFAST uses both passive (circuit) and active (packet) commodity switch components in a unique way to dynamically reconfigure interconnect wiring to suit the topological requirements of scientific applications. Overall the exploration points to several promising directions for practically addressing both the on-chip and off-chip interconnect requirements of future ultrascale systems. / Master of Science

El objetivo de la tesis es es procesado de señales en las bandas de microondas y terahercios mediante dispositivos ópticos operando en la banda de comunicaciones. El procesado mediante tecnología convencional presenta una serie de limitaciones que la tecnología óptica permite solventar. Por un lado, los dispositivos electrónicos de microondas tienen pérdidas considerables y está limitados en ancho de banda. En este caso la tecnlogía de fibra óptica propociona ventajas en términos de bajas pérdidas y ancho de banda prácticamente ilimitado. Por otro lado, el procesado de señales de terahercios se ha llevado a cabo tradicionalmente mediante elementos en espacio libre con los problemas de tamaño y establilidad que ello implica. Gracias al reciente desarrollo de generadores y detectores de terahercios alimentados por luz a 1.55 um el procesado puede llevarse a cabo utilizando tecnología óptica, lo que proporciona sistemas de procesado más compactos y estables. La tesis se centra en el desarrollo de arquitecturas basadas en fibra que solventen las limitaciones actuales del procesado de señales cuyas frecuencias se sitúan entre las bandas de radio sy THz. en el área de procesado fotónico de señles de microondas se estudian diversas arquitecturas. Se propone la aplicación del efecto de mezclado de cuatro ondas en cascada como una manera de incrementar el número de coeficientes de filtros de respuesta finita basados en dispersión. También se propone implementaciones de filtros pasobanda no periódicos útiles en aplicaciones de radiofrecuencia basados en la impresión de filtros ópticos en el dominio eléctrico. En un caso se utiliza una red de Bragg en fibra con un desfase sintonizable en su estructura periódica mientras que en el otro se usa un micro anillo resonante fabricado en silicio. En cuanto al procesado de señales de terahercios de proponen técnicas parea aumentar localmente la densidad espectral de potencia. Una se basa en la distribución no lineal de pulsos ultracortos por fibra óptica mientras que la otra modula el espectro de la fuente óptica en el dominio temporal mediantes despersión y una estructura interferométrica de amplificadores ópticos de semiconductor. Se espera que el aumento de la potencia de terahercios generada, tanto mediante fuentes más eficientes como mediante procesado óptico, permita utlilizar estos sistemas para llevar a cabo espectroscopía no lineal y deteccíon a distancia. Finalmente, también se estudia la generación de retardos ópticos con el objetivo de sustituir las lentas líneas de retardo basadas en espejos y etapas de traslación motorizadas que se utilizan habitualmente. Las soluciones propuestas se basan en saturación de un ampliifcador óptico de semiconductor así como en la modulación banda lateral única con portadora suprimida del espectro de los pulsos. La primera solución proporciona retardos pequeños aunque es escalable y no ensancha los pulsos de femtosegundos, mientras que la segunda consigue retardos considreables a cambio de ensanchar los pulsos debido a la dispersión de tercer orden de la fibra. / Palací López, J. (2013). Optical processing in the microwave and terahertz regions [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/18435