HIGH POWER PULSED FIBER LASER SOURCES AND THEIR USE IN TERAHERTZ GENERATION 

Persistent Link:
http://hdl.handle.net/10150/193797
Title:
HIGH POWER PULSED FIBER LASER SOURCES AND THEIR USE IN TERAHERTZ GENERATION 
Author:
Leigh, Matthew
Issue Date:
2008
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:
In this dissertation I report the development of high power pulsed fiber laser systems. These systems utilize phosphate glass fiber for active elements, instead of the industry-standard silica fiber. Because the phosphate glass allows for much higher doping of rare-earth ions than silica fibers, much shorter phosphate fibers can be used to achieve the same gain as longer silica fibers.This single-frequency laser technology was used to develop an all-fiber actively Q-switched fiber lasers. A short cavity is used to create large spacing between longitudinal modes. Using this method, we demonstrated the first all-fiber Q-switched fiber laser in the 1 micron region.In addition to creating high peak powers with Q-switched lasers, created even higher powers using fiber amplifier systems. High power fiber lasers typically produce spectral broadening through the nonlinear effects of stimulated Raman scattering, stimulated Brullion scattering, and self-phase modulation. The thresholds for these nonlinearities scale inversely with intensity and length. Thus, we used a short phosphate fiber gain stage to reduce the length, and a large core fiber final stage to reduce intensity. In this way we were able to generate high peak power pulses while avoiding visible nonlinearities, and keeping a narrow bandwidth.The immediate goal of developing these high power fiber laser systems was to generate narrowband terahertz radiation. Two different wavelengths were combined into the final amplifier stage at orthogonal polarizations. These were collimated and directed into a GaSe crystal, which has a very high figure of merit for THz generation. The two wavelengths combined in the crystal through the process of nonlinear difference frequency generation. This produced a narrowband beam of THz pulses, at higher powers than previous narrowband THz pulses produced by eyesafe fiber lasers.
Type:
text; Electronic Dissertation
Keywords:
Fiber Amplifier; Fiber Laser; Nonlinear Optics; Q-switched laser; Single Frequency Laser; Terahertz
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Physics; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Peyghambarian, Nasser
Committee Chair:
Peyghambarian, Nasser

Full metadata record

DC FieldValue Language
dc.language.isoENen_US
dc.titleHIGH POWER PULSED FIBER LASER SOURCES AND THEIR USE IN TERAHERTZ GENERATION en_US
dc.creatorLeigh, Matthewen_US
dc.contributor.authorLeigh, Matthewen_US
dc.date.issued2008en_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.abstractIn this dissertation I report the development of high power pulsed fiber laser systems. These systems utilize phosphate glass fiber for active elements, instead of the industry-standard silica fiber. Because the phosphate glass allows for much higher doping of rare-earth ions than silica fibers, much shorter phosphate fibers can be used to achieve the same gain as longer silica fibers.This single-frequency laser technology was used to develop an all-fiber actively Q-switched fiber lasers. A short cavity is used to create large spacing between longitudinal modes. Using this method, we demonstrated the first all-fiber Q-switched fiber laser in the 1 micron region.In addition to creating high peak powers with Q-switched lasers, created even higher powers using fiber amplifier systems. High power fiber lasers typically produce spectral broadening through the nonlinear effects of stimulated Raman scattering, stimulated Brullion scattering, and self-phase modulation. The thresholds for these nonlinearities scale inversely with intensity and length. Thus, we used a short phosphate fiber gain stage to reduce the length, and a large core fiber final stage to reduce intensity. In this way we were able to generate high peak power pulses while avoiding visible nonlinearities, and keeping a narrow bandwidth.The immediate goal of developing these high power fiber laser systems was to generate narrowband terahertz radiation. Two different wavelengths were combined into the final amplifier stage at orthogonal polarizations. These were collimated and directed into a GaSe crystal, which has a very high figure of merit for THz generation. The two wavelengths combined in the crystal through the process of nonlinear difference frequency generation. This produced a narrowband beam of THz pulses, at higher powers than previous narrowband THz pulses produced by eyesafe fiber lasers.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectFiber Amplifieren_US
dc.subjectFiber Laseren_US
dc.subjectNonlinear Opticsen_US
dc.subjectQ-switched laseren_US
dc.subjectSingle Frequency Laseren_US
dc.subjectTerahertzen_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplinePhysicsen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorPeyghambarian, Nasseren_US
dc.contributor.chairPeyghambarian, Nasseren_US
dc.contributor.committeememberJiang, Shibinen_US
dc.contributor.committeememberWright, Ewanen_US
dc.contributor.committeememberBickel, Williamen_US
dc.contributor.committeememberMazumdar, Sumiten_US
dc.identifier.proquest10128en_US
dc.identifier.oclc659750674en_US
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