Optical absorption and anisotropy of refractory oxides fabricated by ion-assisted deposition and ion plating.

Persistent Link:
http://hdl.handle.net/10150/185285
Title:
Optical absorption and anisotropy of refractory oxides fabricated by ion-assisted deposition and ion plating.
Author:
Sprague, Robert Wendell.
Issue Date:
1990
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:
The thickness and refractive index of thin films determines their performance. Thickness variation due to the deposition process is well understood and correctable. Variation in the refractive index due to the deposition process is a considerably more complex problem. In this work two important members of the class of high index refractory materials: Tantalum pentoxide and Titania are investigated. These materials are known to produce very high quality films. Ion plating of tantalum results in the extremely high quality films, but ion plating of titania results in films with absorption that is too high and the process is now no longer used. Ion assisted deposition of titania, however, results in high quality films. The variation in refractive index due to the columnar microstructure of these materials has been eliminated but the subtler aspects of the thin films behavior is more difficult to improve. It is this aspect that I have investigated. In particular what improvements can be made by post deposition annealing of ion plated and ion assisted deposition of Tantalum pentoxide, and can the ion bombardment of Titania result in films with increased birefringence. If this anisotropy can be increased a number of interesting polarizing elements can be produced. These investigations were performed in distinct methods. The absorption of these films required the design and construction of a specialized highly sensitive waveguide apparatus. The investigation of anisotropy involved examining the evolution of form birefringence in situ by polarimetry. A further parameter of interest, although not as yet widely studied in thin films as the effects are small and difficult to observe is material nonlinearity. In the future the design of dynamic filters or coatings for powerful laser systems will require a good means of determining this kind of behavior in thin films. To this end we have designed our absorption instrument to be able to determine changes in refractive index due to a strong external pump beam. These effects are described in chapter three as an indication of future trends in this area.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Physics
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Optical Sciences; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Macleod, H. Angus

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleOptical absorption and anisotropy of refractory oxides fabricated by ion-assisted deposition and ion plating.en_US
dc.creatorSprague, Robert Wendell.en_US
dc.contributor.authorSprague, Robert Wendell.en_US
dc.date.issued1990en_US
dc.publisherThe University of Arizona.en_US
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_US
dc.description.abstractThe thickness and refractive index of thin films determines their performance. Thickness variation due to the deposition process is well understood and correctable. Variation in the refractive index due to the deposition process is a considerably more complex problem. In this work two important members of the class of high index refractory materials: Tantalum pentoxide and Titania are investigated. These materials are known to produce very high quality films. Ion plating of tantalum results in the extremely high quality films, but ion plating of titania results in films with absorption that is too high and the process is now no longer used. Ion assisted deposition of titania, however, results in high quality films. The variation in refractive index due to the columnar microstructure of these materials has been eliminated but the subtler aspects of the thin films behavior is more difficult to improve. It is this aspect that I have investigated. In particular what improvements can be made by post deposition annealing of ion plated and ion assisted deposition of Tantalum pentoxide, and can the ion bombardment of Titania result in films with increased birefringence. If this anisotropy can be increased a number of interesting polarizing elements can be produced. These investigations were performed in distinct methods. The absorption of these films required the design and construction of a specialized highly sensitive waveguide apparatus. The investigation of anisotropy involved examining the evolution of form birefringence in situ by polarimetry. A further parameter of interest, although not as yet widely studied in thin films as the effects are small and difficult to observe is material nonlinearity. In the future the design of dynamic filters or coatings for powerful laser systems will require a good means of determining this kind of behavior in thin films. To this end we have designed our absorption instrument to be able to determine changes in refractive index due to a strong external pump beam. These effects are described in chapter three as an indication of future trends in this area.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectPhysicsen_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineOptical Sciencesen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorMacleod, H. Angusen_US
dc.contributor.committeememberBovard, Bertrand G.en_US
dc.contributor.committeememberWright, Ewanen_US
dc.identifier.proquest9111970en_US
dc.identifier.oclc710834427en_US
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