Evolution and Persistence of Circular and Linear Polarization in Scattering Environments

Persistent Link:
http://hdl.handle.net/10150/566254
Title:
Evolution and Persistence of Circular and Linear Polarization in Scattering Environments
Author:
van der Laan, John David
Issue Date:
2015
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Sensing in scattering environments, such as fog and dust, poses a serious challenge for all optical systems and is important for many critical surveillance applications. The use of polarized light, specifically circularly polarized light, has shown great promise for improving detection range and sensing in highly scattering, real-world environments. While the potential impact to application is significant, the optical science and sensing community lacks data on broad wavelength and environmental parameters where circularly polarized light outperforms linearly polarized light, increasing detection range and signal persistence. In this dissertation I quantify, through simulation and experimental results, the advantage of circularly polarized light in laboratory and real-world scattering environments - focusing on circularly polarized light's superior persistence in these environments. I present new and unique contributions to the study of polarized light in both isotropic (Rayleigh regime) and forward-scattering environments, showing circular polarization's superior persistence increases detection range for real-world environments over broad wavelength and particle size regimes. Utilizing polarization-tracking Monte Carlo simulations for varying particle size, wavelength, and refractive index, I quantify when circular polarization outperforms linear polarization in maintaining the illuminating polarization state for large optical thicknesses, persisting to longer ranges. I identify many real-world environments with particle sizes of radiation fog, advection fog, and Sahara dust where circular polarization outperforms linear polarization over broad wavelength ranges in the infrared spectrum. This enhancement with circular polarization can be exploited to improve sensing range and target detection in obscurant environments that are important in many critical surveillance applications. Conversely, I also identify a few environmental configurations where linear polarization outperforms circular polarization. However, circular polarization's response is generally larger and over broader wavelength ranges in the infrared regime for real-world scattering environments. Experiments were conducted for both 1) isotopically-scattering (Rayleigh regime) environments and 2) forward-scattering environments using polystyrene microspheres with well-defined diameters. These measurements demonstrated that in the forward-scattering environments, circular polarization persists through increasing optical thickness better than linear polarization. Variations in persistence were investigated as a function of collection geometry, angular field of view, and collection area. Persistence for both linear and circular polarization was found to be more susceptible to collection geometry, specifically increased collection area, in the isotropically-scattering (Rayleigh regime) environment. Similarly, linear polarization in the forward-scattering environments is dependent upon changes in collection geometry. Significantly, circular polarization's response is nearly unaffected by variations of both field of view and collection area for the forward-scattering environments. Circular polarization proves to be not only generally better in persistence but also more tolerant of variations in angular collection and collection area compared to linear polarization, making it ideal and flexible for use in optical sensing systems in scattering environments. Finally, I present simulation results that show the evolution of linear and circularly polarized light as it scatters throughout both isotropic (Rayleigh regime) and forward-scattering environments as a function of scattering event. Circularly polarized light persists through a larger number of scattering events longer than linearly polarized light for all forward-scattering environments; but not for scattering in the Rayleigh regime. Circular polarization's increased persistence occurs for both forward and backscattered light. The evolution of the polarization states as they propagate through the various environments are illustrated on the Poincaré sphere after successive scattering events. This work displays individual scattering events as well as a cumulative, measureable result, in an intuitive manner. Throughout this dissertation I quantify the polarization persistence and memory of circularly polarized light in real-world scattering environments over broad wavelength, particle size, and collection-geometry parameter spaces; and for the first time, detail the evolution and modification of both circularly and linearly polarized states through isotropic and forward-scattering environments. These results show how circular polarization can extend range and sensing capability in surveillance sensing applications in real-world scattering environments.
Type:
text; Electronic Dissertation
Keywords:
linear polarization; Mie theory; scattering; Optical Sciences; circular polarization
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Optical Sciences
Degree Grantor:
University of Arizona
Advisor:
Dereniak, Eustace L.

Full metadata record

DC FieldValue Language
dc.language.isoen_USen
dc.titleEvolution and Persistence of Circular and Linear Polarization in Scattering Environmentsen_US
dc.creatorvan der Laan, John Daviden
dc.contributor.authorvan der Laan, John Daviden
dc.date.issued2015en
dc.publisherThe University of Arizona.en
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en
dc.description.abstractSensing in scattering environments, such as fog and dust, poses a serious challenge for all optical systems and is important for many critical surveillance applications. The use of polarized light, specifically circularly polarized light, has shown great promise for improving detection range and sensing in highly scattering, real-world environments. While the potential impact to application is significant, the optical science and sensing community lacks data on broad wavelength and environmental parameters where circularly polarized light outperforms linearly polarized light, increasing detection range and signal persistence. In this dissertation I quantify, through simulation and experimental results, the advantage of circularly polarized light in laboratory and real-world scattering environments - focusing on circularly polarized light's superior persistence in these environments. I present new and unique contributions to the study of polarized light in both isotropic (Rayleigh regime) and forward-scattering environments, showing circular polarization's superior persistence increases detection range for real-world environments over broad wavelength and particle size regimes. Utilizing polarization-tracking Monte Carlo simulations for varying particle size, wavelength, and refractive index, I quantify when circular polarization outperforms linear polarization in maintaining the illuminating polarization state for large optical thicknesses, persisting to longer ranges. I identify many real-world environments with particle sizes of radiation fog, advection fog, and Sahara dust where circular polarization outperforms linear polarization over broad wavelength ranges in the infrared spectrum. This enhancement with circular polarization can be exploited to improve sensing range and target detection in obscurant environments that are important in many critical surveillance applications. Conversely, I also identify a few environmental configurations where linear polarization outperforms circular polarization. However, circular polarization's response is generally larger and over broader wavelength ranges in the infrared regime for real-world scattering environments. Experiments were conducted for both 1) isotopically-scattering (Rayleigh regime) environments and 2) forward-scattering environments using polystyrene microspheres with well-defined diameters. These measurements demonstrated that in the forward-scattering environments, circular polarization persists through increasing optical thickness better than linear polarization. Variations in persistence were investigated as a function of collection geometry, angular field of view, and collection area. Persistence for both linear and circular polarization was found to be more susceptible to collection geometry, specifically increased collection area, in the isotropically-scattering (Rayleigh regime) environment. Similarly, linear polarization in the forward-scattering environments is dependent upon changes in collection geometry. Significantly, circular polarization's response is nearly unaffected by variations of both field of view and collection area for the forward-scattering environments. Circular polarization proves to be not only generally better in persistence but also more tolerant of variations in angular collection and collection area compared to linear polarization, making it ideal and flexible for use in optical sensing systems in scattering environments. Finally, I present simulation results that show the evolution of linear and circularly polarized light as it scatters throughout both isotropic (Rayleigh regime) and forward-scattering environments as a function of scattering event. Circularly polarized light persists through a larger number of scattering events longer than linearly polarized light for all forward-scattering environments; but not for scattering in the Rayleigh regime. Circular polarization's increased persistence occurs for both forward and backscattered light. The evolution of the polarization states as they propagate through the various environments are illustrated on the Poincaré sphere after successive scattering events. This work displays individual scattering events as well as a cumulative, measureable result, in an intuitive manner. Throughout this dissertation I quantify the polarization persistence and memory of circularly polarized light in real-world scattering environments over broad wavelength, particle size, and collection-geometry parameter spaces; and for the first time, detail the evolution and modification of both circularly and linearly polarized states through isotropic and forward-scattering environments. These results show how circular polarization can extend range and sensing capability in surveillance sensing applications in real-world scattering environments.en
dc.typetexten
dc.typeElectronic Dissertationen
dc.subjectlinear polarizationen
dc.subjectMie theoryen
dc.subjectscatteringen
dc.subjectOptical Sciencesen
dc.subjectcircular polarizationen
thesis.degree.namePh.D.en
thesis.degree.leveldoctoralen
thesis.degree.disciplineGraduate Collegeen
thesis.degree.disciplineOptical Sciencesen
thesis.degree.grantorUniversity of Arizonaen
dc.contributor.advisorDereniak, Eustace L.en
dc.contributor.committeememberDereniak, Eustace L.en
dc.contributor.committeememberKemme, Shanalyn A.en
dc.contributor.committeememberSchwiegerling, James T.en
All Items in UA Campus Repository are protected by copyright, with all rights reserved, unless otherwise indicated.