Thesis (Ph. D.)--Washington State University, December 2008. / Title from PDF title page (viewed on Apr. 13, 2009). "School of Mechanical and Materials Engineering." Includes bibliographical references.

Thesis (M.S.)--University of Michigan, 1963.

This thesis is concerned with the design and development of compact, all-solid-state femtosecond pulse lasers with low pump power requirements. A number of directly-diode- pumped laser systems based on the gain materials Cr3:LiSrGaF6 (chromium-doped lithium strontium aluminium fluoride) and Cr3:LiSrGaF6 (chromium-doped lithium strontium gallium fluoride) pumped with AlGaInP laser diodes are described. The motivation behind this work was the development of portable, low-noise and lower cost ultrashort pulse lasers for a number of low-power applications such as the characterisation of electron-optical streak camera systems. The investigation into the modelocking of lasers with modest intracavity powers was also an important challenge. The achievement of a battery-powered, compact and efficient laser system represents an excellent outcome for this research programme. Major consideration is given to the key factors that determine both the cw and modelocking thresholds of an ultrashort-pulse laser. In particular, the reduction of intracavity optical losses by designing the laser to operate with fewer cavity elements, the optimisation of second-order and higher-order dispersion for efficient modelocked operation and the inclusion of a semiconductor saturable absorber mirror for increased stability are discussed. This has enabled pump thresholds to be reduced to a level permitting, for the first time, the use of diffraction-limited, narrow-stripe laser diodes for efficient, low-power optical pumping. A number of laser oscillators with novel cavity designs and progressively lower pump thresholds are described. Pulses as short as 57 fs and average output powers as high as 9 mW for only 80 mW of incident pump power are reported for a battery powered femtosecond Cr:LiSAF laser. This represents an overall electrical-to-optical conversion efficiency of approximately 1% which is excellent for a femtosecond pulse laser system. In addition, the amplitude and phase noise performance is shown to be exceptionally good and is believed to be the best yet reported for this type of ultrashort pulse laser. The design and demonstration of highly compact, ultrashort-pulse lasers incorporating novel resonator configurations and simplified dispersion compensation schemes are then described. These lasers produced sub-ps pulses at cavity frequencies as high as 450 MHz.

Made available in DSpace on 2014-10-09T12:28:17Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:56:45Z (GMT). No. of bitstreams: 0 / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Made available in DSpace on 2014-10-09T12:27:54Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:04:48Z (GMT). No. of bitstreams: 0 / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Made available in DSpace on 2014-10-09T12:28:17Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:56:45Z (GMT). No. of bitstreams: 0 / Lasers emitindo no azul vêm sendo largamente utilizado em diversas aplicações como por exemplo, blu-ray, displays, e podem representar uma excelente fonte de bombeio para o meio ativo Ti:safira. Neste trabalho utilizamos um cristal de Nd:YAG, com diffusion bonded end-caps e um bombeamento com diodo semicondutor no comprimento de onda de 803,2 nm, dessintonizado do pico de absorção 808 nm de neodímio, a fim de minimizar os efeitos de lente térmica do Nd:YAG. Dessa forma, conseguiu-se uma melhor distribuição de temperatura dentro do cristal. Testando diferentes raios de curvatura para os espelhos da cavidade, obteve-se a melhor relação entre a cintura do feixe de bombeio e feixe laser, alcançando 6,75 W cw (continuous wave) de potência de saída laser em 946 nm e slope efficiency de 48%. Em um segundo passo foi inserido, em diferentes tipos de cavidades, um cristal dobrador de freqüência para obtenção de emissão no azul em 473 nm, e a potência de saída azul foi medida em função da potência absorvida. / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Made available in DSpace on 2014-10-09T12:27:54Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:04:48Z (GMT). No. of bitstreams: 0 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Lasers de estado sólido sintonizáveis com uma estreita largura de linha de emissão na região do vermelho são uma alternativa conveniente aos lasers de corante para aplicações em espectroscopia de alta resolução. Nesse trabalho, foram investigados lasers contínuos de Nd:YLiF4 e Nd:YVO4 operando em frequência única na região de 1,32 - 1,34μm, assim como a geração de segundo harmônico (GSH) desses lasers usando cristais de BiB3O6 (BiBO) e KTiOPO4 com inversão periódica de domínios (ppKTP), para a obtenção da emissão no vermelho (0,65 - 0,67μm). Utilizando um laser de Nd:YVO4 operando em frequência única em uma configuração em anel com um cristal não linear BiBO do tipo I, demonstrou-se o recorde de 680mW no vermelho em 671,1nm, sem a utilizaçãde nenhum elemento seletivo. Uma intonia em todo o ganho (~4 nm) foi obtida atravésda inserção de um etalon com filme refletor (R = 40%) e com 100μm de espessura, o que reduziu a potência de saída no vermelho para 380mW no comprimento de onda de maior ganho (671,15 nm). Em 1342nm foi demonstrada uma potência de saída de 1,5W em frequência única quando utilizado um espelho de saída com transmissão de 2%. Foi demonstrado ainda uma ótima eficiência de conversão de segundo harmônico em um laser em anel de Nd:YLF na polarização π (λ = 1321,5nm) quando usando um cristal de ppKTP. Este laser forneceu 1,4W em frequência única no vermelho em 660,5nm. Essa potência é a máxima que pode ser extraída desse laser no segundo harmônico e no fundamental quando utilizado um espelho com transmissão ótima. Utilizando um etalon com filme refletor (R = 25%), o laser pôde ser sintonizado em Δλ ~ 1,6nm. / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP / FAPESP: 06/57945-3

Thesis (MSc (Physics. Institute for Laser Research))--University of Stellenbosch, 2005. / This thesis consists of two parts: a discussion on diode-pumped solid-state lasers and a detailed description of the development of a diode-end-pumped Nd:YLF laser. A background motivation, which places this research area in perspective, is also given. Part One introduces solid-state lasers and their physics. The focus is on the Nd3+ active ion and describes its energy level structure as a typical four-level solid-state laser. An overview of optical pump sources for solid-state lasers is given, focussing on the construction, operation and advantages of diode lasers. It is motivated that diode-end-pumping solid-state lasers produce laser systems with the highest efficiency and diffraction limited beam quality. It is, however, emphasised that power scaling of diode-end-pumped solid-state lasers is problematic due to localised heat generation in the solid-state laser medium. The adverse effect of heat generation on the laser performance is also described. In the design of diode-endpumped solid-state lasers, the management of thermal effects is suggested as the approach to scale the output power of these lasers. Part Two of the thesis describes the design and the results of a novel high-power diode-end-pumped solid-state laser developed at the Laser Research Institute. The description of the design is split into three components: the laser material, the pump source and the laser resonator. The choice of laser material is motivated in detail, focussing on Nd:YLF’s advantage of having a very weak thermal lens when operated on the σ-polarization at 1053 nm. Its disadvantage of having a low fracture limit is also highlighted, but the approach to power scale it to the multi-10-watt level, with the use of low doping concentration, a low absorption pump wavelength, and a large pump beam, is described. It is further shown that this approach led to the development of a novel laser resonator, which allows a large fundamental mode in the laser material to match the large pump beam, and it can compensate for the astigmatic thermal lens in Nd:YLF. The experimental results of the high-power diode-end-pumped Nd:YLF laser are presented, showing the influence of doping concentration, output coupling efficiency and resonator adjustments on the continuous wave and Q-switched laser performance. It is shown that the optimum laser parameters were determined, resulting in the Nd:YLF laser producing more than 26 W of continuous wave output power with a close to diffraction limited beam quality (M2 < 1.4), and more than 3 mJ of energy per pulse at a repetition rate of 6 kHz when Q-switched. It is concluded that the powerscaling concept proved to be efficient and that further power scaling would be possible with this scheme.

by Lam King Shun. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references (leaves [40-41]). / by Lam King Shun. / Acknowledgement --- p.i / Biographical Sketch --- p.ii / Abstract --- p.iii / Table of Contents --- p.iv / Chapter Chapter One --- Introduction --- p.1 / Chapter Chapter Two --- The Sol-Gel Derived Silica / Chapter 2.1 --- Introduction to the so-gel science --- p.3 / Chapter 2.2 --- The procedure of the silica formation --- p.5 / Chapter 2.3 --- During the sol-gel process --- p.7 / Chapter 2.4 --- The silica characterization --- p.12 / Chapter 2.4.1 --- Physical properties --- p.12 / Chapter 2.4.2 --- Optical properties --- p.13 / Chapter 2.5 --- Sample preparation --- p.15 / Chapter Chapter Three --- Laser Experiments / Chapter 3.1 --- Basic principle of dye laser --- p.16 / Chapter 3.2 --- Experimental procedure --- p.20 / Chapter 3.3 --- Data and discussion --- p.23 / Chapter 3.3.1 --- Spectral and temporal behaviour --- p.2 3 / Chapter 3.3.2 --- The performance of the sol-gel silica laser --- p.37 / Chapter Chapter Four --- Conclusions and Suggestions for Further Work --- p.39 / References

Zhu Xiao Lei. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (p. 116-121). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.