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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Generation of tunable femtosecond laser pulses and the construction of an ultrafast pump-probe spectrometer

Morrison, Vance. January 2008 (has links)
An ultrafast UV-visible spectrometer was designed and implemented. An optical parametric amplifier was constructed to be used as a pump source for the spectrometer. Using nonlinear optical processes and an 800 nm ultrashort pulses, tunable infrared(IR) light was produced with a wavelength range of ∼.1 mum to 3 mum. The IR light was then mixed with 800 nm light to produce tunable visible light with a wavelength range of 466 nm to 600 nm. Supercontinuum (SC) was used as the probe pulse of the spectrometer, providing a large observation bandwidth. Commercially purchased fast spectrometers were used as the detection mechanism. The characterization of the set up, as well the observation of some ultrafast molecular dynamics observed in 8-hydroxy-1,3,6-pyrenetrisulfonic acid, are presented.
62

Plasma waveguides for high-intensity laser pulses

Spence, David James January 2001 (has links)
This thesis documents the development of plasma waveguides for high-intensity laser pulses. Initial work concentrated on the development of the discharge-ablated capillary waveguide, based on the work of A. Zigler (Zigler, A., Y. Ehrlich, C. Cohen, J. Krall and P. Sprangle, J. Opt. Soc. Am. B 13, 68). The waveguide was shown to be capable of guiding picosecond laser pulses with an intensity of 10<sup>16</sup> W cm<sup>-2</sup> over a length of 10 mm. The pulse energy transmission of the capillary was increased from 48% to 70% when the discharge was fired. An interferometry-based measurement technique was developed, allowing measurement of the electron density profile formed in the capillary waveguide. These measurements were used as input to a numerical simulation that predicted the propagation of intense laser pulses through partially-ionised plasma waveguides. Numerical simulations accurately reproduced the picosecond pulse guiding results, and gave important insights into the properties and severe drawbacks of partially-ionised waveguides. Previous work on partially-ionised plasma waveguides has not fully explored the implications of the propagation of intense pulses through the partially-ionised plasma. For polypropylene waveguides, it was shown that for pulses with an intensity of 10<sup>16</sup> W cm<sup>-2</sup>, the waveguide is not capable of high-quality guiding. However, for pulses with an intensity of greater than 10<sup>17</sup> W cm<sup>-2</sup>, high-quality guiding is predicted through the partially-ionised waveguide in a new regime called "quasi-matched guiding". A novel gas-filled capillary discharge waveguide was designed and built. The device was shown to form a guiding channel inside a capillary pre-filled with gas. Interferometry measurements of the electron density profile formed in a hydrogen-filled capillary discharge waveguide showed that an approximately parabolic plasma waveguide could be formed in an essentially fully-ionised hydrogen plasma. The device was used to guide femtosecond laser pulses, with an intensity of 10<sup>17</sup> W cm<sup>-2</sup>, over distances of 20 and 40 mm, with a pulse energy transmission of 92% and 82% respectively. For the 20 mm-long waveguide, the peak intensity in the output plane of the waveguide was 70% of that at the waveguide input. These results indicate the lowest coupling and insertion losses of any waveguide published to date. The gas-filled capillary discharge waveguide is shown to be capable and versatile, and is suited for use as a tool in other applications. The use of the waveguide in the fields of XUV lasers and laser wakefield acceleration is discussed.
63

Femtosecond laser microprocessing of aluminum films and quartz

Doerr, David W. January 1900 (has links)
Thesis (Ph.D.)--University of Nebraska-Lincoln, 2007. / Title from title screen (site viewed Dec. 4, 2007). PDF text: xii, 80 p. : ill. ; 6 Mb. UMI publication number: AAT 3273191. Includes bibliographical references. Also available in microfilm and microfiche formats.
64

Molecular imaging using femtosecond laser pulses

Dooley, Patrick W. Corkum, Paul B. January 2003 (has links)
Thesis (Ph.D.)--McMaster University, 2004. / Supervisor: Paul B. Corkum. Includes bibliographical references.
65

Enhanced hot electron confinement and isochoric heating in high contrast ultra-intense laser produced plasmas via novel conical micro-target design

Rassuchine, Jennifer Melissa. January 2007 (has links)
Thesis (Ph. D.)--University of Nevada, Reno, 2007. / "December, 2007." Includes bibliographical references (leaves 244-254). Online version available on the World Wide Web.
66

Femtosecond Cr⁴⁺:forsterite laser for applications in telecommunications and biophotonics /

McWilliam, Alan. January 2007 (has links)
Thesis (Ph.D.) - University of St Andrews, March 2007.
67

Versatile high resolution dispersion measurements in semiconductor photonic nanostructures using ultrashort pulses /

Bell, Matthew Richard. January 2007 (has links)
Thesis (Ph.D.) - University of St Andrews, May 2007.
68

Optical micromanipulation using ultrashort pulsed laser sources /

Little, Helen. January 2007 (has links)
Thesis (Ph.D.) - University of St Andrews, May 2007.
69

Ultrashort-pulse generation from quantum-dot semiconductor diode lasers /

Cataluna, Maria Ana. January 2007 (has links)
Thesis (Ph.D.) - University of St Andrews, December 2007.
70

A UV preionized TEA CO₂ laser amplifier Master's project /

Miller, Marshall. Bach, David Rudolph. January 1900 (has links)
Thesis (M.S.)--University of Michigan, (1977?).

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