Dynamic response and material processing of photorefractive polymer composites

Persistent Link:
http://hdl.handle.net/10150/284284
Title:
Dynamic response and material processing of photorefractive polymer composites
Author:
Herlocker, Jon Alan
Issue Date:
2000
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:
This dissertation describes advances in the photorefractive dynamic response, and in the understanding of response limitations. In a PVK/ECZ based composite using a tolane chromophore and TNFDM sensitization, a photorefractive response time constant of 4 ms was observed at an applied field (Eₐ) of 95 V/μm with a writing fluence of 0.5 W/cm², while the birefringence response time was under a millisecond. This showed that the chromophore orientational response does not limit speed, and suggests further investigation of photogeneration and transport processes to improve dynamic response. Another segment of research investigated performance changes by exposure under working conditions. Photorefractive properties for composites using chromophores of varied ionization potential (I(p)) were characterized as a function of exposure at Eₐ = 80 V/um, up to 10⁴ J/cm² total optical field exposure. The response time and photoconductivity were found to fatigue for all samples, but a higher chromophore I(p) was correlated to greater stability. The four-wave mixing dependence upon E a showed a variation in trap density with exposure which verifies the role of the C₆₀ anion, the ionized sensitizer, as a photorefractive trap. The third segment of research was the proof-of-principle of a photorefractive injection molding process. Photorefractive properties of molded materials were verified by four-wave mixing and two-beam coupling measurements. At Eₐ = 95 V/μm a diffraction efficiency of 25-30% and a gain coefficient near 50 cm⁻¹ was observed. This shows industrial processing potential of these materials and provides a path from hand crafted devices to mass-production techniques, promoting commercial acceptance.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Physics, Optics.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Optical Sciences
Degree Grantor:
University of Arizona
Advisor:
Kippelen, Bernard

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleDynamic response and material processing of photorefractive polymer compositesen_US
dc.creatorHerlocker, Jon Alanen_US
dc.contributor.authorHerlocker, Jon Alanen_US
dc.date.issued2000en_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.abstractThis dissertation describes advances in the photorefractive dynamic response, and in the understanding of response limitations. In a PVK/ECZ based composite using a tolane chromophore and TNFDM sensitization, a photorefractive response time constant of 4 ms was observed at an applied field (Eₐ) of 95 V/μm with a writing fluence of 0.5 W/cm², while the birefringence response time was under a millisecond. This showed that the chromophore orientational response does not limit speed, and suggests further investigation of photogeneration and transport processes to improve dynamic response. Another segment of research investigated performance changes by exposure under working conditions. Photorefractive properties for composites using chromophores of varied ionization potential (I(p)) were characterized as a function of exposure at Eₐ = 80 V/um, up to 10⁴ J/cm² total optical field exposure. The response time and photoconductivity were found to fatigue for all samples, but a higher chromophore I(p) was correlated to greater stability. The four-wave mixing dependence upon E a showed a variation in trap density with exposure which verifies the role of the C₆₀ anion, the ionized sensitizer, as a photorefractive trap. The third segment of research was the proof-of-principle of a photorefractive injection molding process. Photorefractive properties of molded materials were verified by four-wave mixing and two-beam coupling measurements. At Eₐ = 95 V/μm a diffraction efficiency of 25-30% and a gain coefficient near 50 cm⁻¹ was observed. This shows industrial processing potential of these materials and provides a path from hand crafted devices to mass-production techniques, promoting commercial acceptance.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectPhysics, Optics.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineOptical Sciencesen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorKippelen, Bernarden_US
dc.identifier.proquest9992114en_US
dc.identifier.bibrecord.b41170635en_US
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