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Gigawatt Picosecond Dye Lasers and Ultrafast Processes in Semiconductor Lasers


Koch, Thomas Lawson (1982) Gigawatt Picosecond Dye Lasers and Ultrafast Processes in Semiconductor Lasers. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/61ca-rp72.


This thesis is a theoretical and experimental investigation of a gigawatt picosecond dye laser oscillator-amplifier system, and the application of that system to the study of ultrafast lasing and carrier dynamics in semiconductor lasers.

Beginning with a review of traveling wave rate equations, nonlinear pulse propagation in a generalized two-level amplifying/absorbing medium is discussed. This permits a qualitative treatment of synchronously mode-locked dye lasers. The formalism is then refined to provide a quantitative analysis of picosecond dye laser amplifier chains, including amplified spontaneous emission, saturable absorbers used for amplifier stage isolation, gain saturation with "angular hole-burning" and triplet losses, and linear and nonlinear pulse shaping effects.

Experimentally, the construction and operation of a three stage Nd:YAG laser pumped picosecond dye laser amplifier chain is described. Numerical modeling is used to compare the theoretical analysis with the experimental results. In addition, a brief discussion of picosecond time domain measurement techniques is presented, focussing on nonlinear optical methods. This includes a parametric sum frequency upconversion gating technique used extensively in this work to provide linear, picosecond resolution temporal measurements of optical pulses which are synchronized to the dye laser pulses.

The output of the picosecond dye laser system is used to optically generate high carrier densities in semiconductor lasers, and the ensuing short pulse lasing dynamics are investigated and compared to the predictions of a simple rate equation analysis. Novel effects are observed in the spectrally resolved temporal measurements of the lasing output from picosecond optically pumped buried heterostructure semiconductor lasers. A model is developed which includes both broadband stimulated emission as well as many-valley and hot electron effects in the semiconductor, and the model is in close agreement with the observed behavior. The conclusion is drawn that the picosecond lasing dynamics of semiconductor lasers can be understood if the conventional rate equations are abandoned in favor of a more fundamental analysis which includes not just the dynamics of the optical energy exchange in the laser cavity, but the detailed picosecond dynamics of the semiconductor material as well.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Applied Physics
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Applied Physics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Yariv, Amnon
Thesis Committee:
  • Yariv, Amnon (chair)
  • Bridges, William B.
  • Nicolet, Marc-Aurele
  • Psaltis, Demetri
  • Zewail, Ahmed H.
Defense Date:24 May 1982
Funding AgencyGrant Number
NSF Graduate Research FellowshipUNSPECIFIED
Earle C. Anthony FellowshipUNSPECIFIED
Record Number:CaltechETD:etd-10042006-130634
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:3920
Deposited By: Imported from ETD-db
Deposited On:12 Oct 2006
Last Modified:16 Apr 2021 23:14

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