Persistent Link:
http://hdl.handle.net/10150/280473
Title:
Dynamically refocused Rayleigh beacons for adaptive optics
Author:
Georges III, James Augustus
Issue Date:
2003
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:
Dynamic refocus, DR, for adaptive optics has been proposed as a process that, over a given range, will maintain a sharp image of the Rayleigh backscatter due to a laser pulse rising in the atmosphere. Sharp focus is important when the backscatter from an artificial star is used for wavefront sensing. The wavefront variance associated with a Shack Hartmann wavefront sensor is inversely related to the photon return (in the shot noise limited case) and is dependant on the square of the beacon image's angular size. For the same spot size the photon return of a dynamically refocused Rayleigh beacon is increased by a factor of twelve over a system without DR. Here we present the implementation and results of the first operational Rayleigh beacon DR system. The DR system is designed for use on the MMT with five Rayleigh laser beacons projected on a 120arcsec regular pentagon. It was tested on the Mt. Bigelow 61" telescope, configured to act as an off-axis MMT subaperture. The results show the simultaneous DR of five Rayleigh beacons where a beacon image is dynamically refocused from 7arcsec FWHM to 2.7arcsecFWHM.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Engineering, Electronics and Electrical.; Physics, Optics.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Optical Sciences
Degree Grantor:
University of Arizona
Advisor:
Angel, Roger

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleDynamically refocused Rayleigh beacons for adaptive opticsen_US
dc.creatorGeorges III, James Augustusen_US
dc.contributor.authorGeorges III, James Augustusen_US
dc.date.issued2003en_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.abstractDynamic refocus, DR, for adaptive optics has been proposed as a process that, over a given range, will maintain a sharp image of the Rayleigh backscatter due to a laser pulse rising in the atmosphere. Sharp focus is important when the backscatter from an artificial star is used for wavefront sensing. The wavefront variance associated with a Shack Hartmann wavefront sensor is inversely related to the photon return (in the shot noise limited case) and is dependant on the square of the beacon image's angular size. For the same spot size the photon return of a dynamically refocused Rayleigh beacon is increased by a factor of twelve over a system without DR. Here we present the implementation and results of the first operational Rayleigh beacon DR system. The DR system is designed for use on the MMT with five Rayleigh laser beacons projected on a 120arcsec regular pentagon. It was tested on the Mt. Bigelow 61" telescope, configured to act as an off-axis MMT subaperture. The results show the simultaneous DR of five Rayleigh beacons where a beacon image is dynamically refocused from 7arcsec FWHM to 2.7arcsecFWHM.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectEngineering, Electronics and Electrical.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.advisorAngel, Rogeren_US
dc.identifier.proquest3119947en_US
dc.identifier.bibrecord.b45631736en_US
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