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Optical pulse propagation in media exhibiting a third order nonlinear polarization


Comly, Jack Clifton (1974) Optical pulse propagation in media exhibiting a third order nonlinear polarization. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/RW6Z-5V08.


A theoretical investigation is made of two types of distortions, self phase modulation and self-focusing, produced when an intense optical pulse propagates in a medium whose induced polarization contains terms cubic in the field strength. The first analysis indicates that the insertion of such a medium into a laser cavity can result in the generation of a train of very stable, reproducible, bandwidth-limited pulses. By using a "circulating pulse" model, the physical processes involved are clarified, particularly in the case of high gain in the amplifying medium. Examples are given of the Q-switched operation of such a laser, for which the pulse train differs considerably from that of conventional mode-locked systems. A second analysis deals with the steady-state self-focusing of non-axisymmetrical beams; several approaches are used to derive the increase in the threshold power for elliptical-Gaussian beam shapes. As an alternative to a fully numerical solution, a series of increasingly accurate approximate results are obtained in the form of parameterized beam functions. When an Action-Integral minimization technique is employed to optimize these parameters, the method is capable of describing the self-focusing process in some detail.

Item Type:Thesis (Dissertation (Ph.D.))
Degree Grantor:California Institute of Technology
Division:Physics, Mathematics and Astronomy
Major Option:Physics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Yariv, Amnon
Thesis Committee:
  • Unknown, Unknown
Defense Date:20 May 1974
Record Number:CaltechETD:etd-10252005-092652
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:4247
Deposited By: Imported from ETD-db
Deposited On:25 Oct 2005
Last Modified:21 Dec 2019 03:01

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PDF (Comly_jr_jc_1974.pdf) - Final Version
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