DEVELOPMENT OF A FREQUENCY-SWITCHED LASER FOR INFRARED TIME RESOLVED SPECTROSCOPY.

Persistent Link:
http://hdl.handle.net/10150/187847
Title:
DEVELOPMENT OF A FREQUENCY-SWITCHED LASER FOR INFRARED TIME RESOLVED SPECTROSCOPY.
Author:
SCOTTI, RONALD EDWARD.
Issue Date:
1982
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 objective of this thesis is to describe the development, construction and use of a new tool for optical coherent transient spectroscopy. The new tool is a frequency-switched CO₂ laser. A highly stable laser design was modified to include an intra cavity electro-optic modulator, which al lows the output of the laser to be frequency-switched. The frequency modulated output is used in spectroscopic experiments whose goals are the determination of decay rates for infrared moIecuIar transitions. The use of a frequency-switched laser is the most prom i sing means of making such measurements on nonpoIar molecules. The use of an electro-optic crystal inside a laser cavity introduces a number of fundamental problems which must be overcome before the instrument can be used to make useful spectroscopic measurements. These problems are brought about by the need for a stable laser amplitude and frequency output. The development of a novel stabilization technique to overcome these problems is documented in this thesis. Also included in this thesis is a description of the microcomputer and associated electronics necessary to integrate the laser into an experimental apparatus capable of performing signal averaging and background subtraction on raw time resolved data. The final chapters of this work describe experiments and results of measurements of the scattering cross sect ions of a nonpolar molecule with rare gas perturbers. The nonpolar molecule is SF₆ and the rare gas collision partners are Helium, Argon, and Xenon. The results indicate that the scattering cross section for state changing collisions displays a mass dependance predicted by classical collision theory. However, the measured cross sections for elastic velocity-changing collisions appears to be mass independent, which is at variance with theory.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Laser spectroscopy.; Carbon dioxide lasers.; Collisions (Nuclear physics); Infrared spectroscopy.; Cross sections (Nuclear physics) -- Scattering.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Optical Sciences; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Shoemaker, Richard L.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleDEVELOPMENT OF A FREQUENCY-SWITCHED LASER FOR INFRARED TIME RESOLVED SPECTROSCOPY.en_US
dc.creatorSCOTTI, RONALD EDWARD.en_US
dc.contributor.authorSCOTTI, RONALD EDWARD.en_US
dc.date.issued1982en_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 objective of this thesis is to describe the development, construction and use of a new tool for optical coherent transient spectroscopy. The new tool is a frequency-switched CO₂ laser. A highly stable laser design was modified to include an intra cavity electro-optic modulator, which al lows the output of the laser to be frequency-switched. The frequency modulated output is used in spectroscopic experiments whose goals are the determination of decay rates for infrared moIecuIar transitions. The use of a frequency-switched laser is the most prom i sing means of making such measurements on nonpoIar molecules. The use of an electro-optic crystal inside a laser cavity introduces a number of fundamental problems which must be overcome before the instrument can be used to make useful spectroscopic measurements. These problems are brought about by the need for a stable laser amplitude and frequency output. The development of a novel stabilization technique to overcome these problems is documented in this thesis. Also included in this thesis is a description of the microcomputer and associated electronics necessary to integrate the laser into an experimental apparatus capable of performing signal averaging and background subtraction on raw time resolved data. The final chapters of this work describe experiments and results of measurements of the scattering cross sect ions of a nonpolar molecule with rare gas perturbers. The nonpolar molecule is SF₆ and the rare gas collision partners are Helium, Argon, and Xenon. The results indicate that the scattering cross section for state changing collisions displays a mass dependance predicted by classical collision theory. However, the measured cross sections for elastic velocity-changing collisions appears to be mass independent, which is at variance with theory.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectLaser spectroscopy.en_US
dc.subjectCarbon dioxide lasers.en_US
dc.subjectCollisions (Nuclear physics)en_US
dc.subjectInfrared spectroscopy.en_US
dc.subjectCross sections (Nuclear physics) -- Scattering.en_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.advisorShoemaker, Richard L.en_US
dc.identifier.proquest8217458en_US
dc.identifier.oclc681971792en_US
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