Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 18 of 18 for “"Geometric Optics"”.
-
On Generalized Solutions to Some Problems in Electromagnetism and Geometric Optics
The Maxwell equations of electromagnetism form the foundation of classical electromagnetism, and are of interest to mathematicians, physicists, and engineers alike. The first part of this thesis concerns boundary value problems for the anisotropic Maxwell equations in Lipschitz domains. In this …
-
Theory and Experiments of Scattering From Microscale Random Rough and Deterministic Surfaces
… incident wavelength, incident angles and surface geometric parameters on the reflection distribution. A geometric optics approximation to the rigorous electromagnetic theory is developed for random rough surfaces. The approximate results agree well with the FTIR experimental findings, indicating …
-
Theoretical and Experimental Study of Low-Finesse Extrinsic Fabry-Perot Interferometric Fiber Optic Sensors
… and sensor head imperfections. %Previously, only geometric-optics are available to analyze MMF-EFPI sensors which approximate the light in MMF as rays propagating in different directions. Geometric-optics theory has fundenmental limitations because it is approximate and only valid for limited …
-
Modeling Collective Behavior of Dislocations in Crystalline Materials
… to the Hamilton-Jacobi equations governing geometric optics and level set methods in the following physical contexts: annihilation of dislocations, expansion of a polygonal dislocation loop and operation of a Frank-Read source. The weak solutions to these equations are not unique, and the …
-
ΜΕΛΕΤΗ ΟΡΘΟΓΩΝΙΚΩΝ ΚΑΙ ΤΡΙΓΩΝΙΚΩΝ ΜΙΚΡΟΤΑΙΝΙΑΚΩΝ ΚΕΡΑΙΩΝ
… IS CARRIED OUT BY THE USE OF THE OPTICAL RAYS (GEOMETRIC OPTICS THEORY) METHOD. CLOSED FORM EXPRESSIONS FOR THE TOTAL INTERNAL FIELD (UNDER THE PATCH) AND THE INPUT IMPEDANCE ARE GIVEN WITH THE AID OF AN ANGULARLY DEPENDED REFLECTION COEFFICIENT OFA TEM WAVE OBLIQUELLY INCIDEND OF THE EDGE OF …
-
High-frequency electromagnetic wave scattering from rough surfaces
… (SBR) method, is based on a combination of the geometric optics (GO) theory and the physical optics (PO) theory. The SBR method improves on the Kirchhoff approximation by considering the mutual interactions between the irregularities of the surface (i.e., shadowing and multiple scattering are …
-
Theory of phasor-field imaging
… of P-field propagation using paraxial wave optics and demonstrate how it can be used to form images of hidden diffuse targets both computationally and with physical lenses. In both cases, we find that hidden target planes can be imaged at the modulation-wavelength diffraction limit, despite …
-
Visual pathology rectification
… the user. Another possible method is the use of geometric optics. Optics describe the properties of a ray of light as it propagates through an optical system. These properties are described in a transfer matrix, which is then used to improve an image for a visual impaired user. Results show that …
-
A WENO finite difference scheme for a new class of Hamilton-Jacobi equations in electroelastostatics
… notably, optimal control, differential games, geometric optics, and image processing. This thesis presents a new numerical method to solve a new class of Hamilton-Jacobi equation that has recently appeared in the context of nonlinear electroelastostatics. In a pioneering contribution, Crandall …
-
The Calderón problem for connections
… as follows: we construct the special Complex Geometric Optics solutions oscillating in the vertical direction, that concentrate near geodesics and use their density in an integral identity to reduce the problem to a suitable $X$-ray transform on $M_0$. The construction is based on our proof of …
-
Ultrathin crystalline silicon solar cells incorporating advanced light-trapping structures
… superior to periodic or random structures with geometric-optics-scale features. Through the synthesis of experimental and theoretical evidence, the case is constructed that wavelength-scale light-trapping structures are in fact comparable to conventional random pyramid surface structures for …
-
Annular Beam Shaping And Optical Trepanning
… depth and taper. The ray tracing technique of geometrical optics is employed to design the necessary optics to transform a Gaussian laser beam into an annular beam of different intensity profiles. Such profiles include half Gaussian with maximum intensities at the inner and outer surfaces of …
-
On the parallels between the Maxwell and Dirac equations
… seminal analogy between classical mechanics and geometric optics---a correspondence that ultimately seeded the development of quantum mechanics. In this work, in the same spirit, we explore deeply the similarity between the Maxwell and Dirac equations. We reformulate the Dirac equation in an …
-
Nonlinear PDE and Optical Surfaces Design
We introduce two models to design near field reflectors in R^3 that solve an inverse problem in radiometry, taking into account the inverse square law of irradiance. The problem leads to a Monge-Ampere type inequality. The surfaces in the first model are strictly convex and require to be far from …
-
Numerical modeling and ray tracing of SPatIal Frequency modulation for Imaging
This thesis presents the first full geometric and physical optics characterization of aberrations and the performance of a simple system that implements SPatIal Frequency modulation for Imaging (SPIFI). SPIFI utilizes a chirped frequency mask that modulates the intensity of light along a single axis …
-
Creation and Experimental Validation of a Numerical Model of a Michelson Interferometer
… of the investigator in the realm of physical optics, and by the need to make a useful analytical tool available to other investigators in the larger effort.
-
The Role of Mirror Errors in Solar Energy Conversion
Sunlight is an abundant and renewable source of energy, and the expanding solar industry uses many different methods to convert this energy to work. Some of these methods (engines) use mirrors to reflect radiation. However, the mirrors are not perfect and have slope, shape, tracking, and …
-
The Role of Mirror Errors in Solar Energy Conversion
Sunlight is an abundant and renewable source of energy, and the expanding solar industry uses many different methods to convert this energy to work. Some of these methods (engines) use mirrors to reflect radiation. However, the mirrors are not perfect and have slope, shape, tracking, and …