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A study and analysis of high energy laser (HEL) systems aboard tactical aircraft is performed. The FA-18E/F Hornet and F-35 Joint Strike Fighter (JSF), equipped with solid-state HEL systems, are the main subjects of the study. Considerations of power generation and thermal management for a fighter-sized HEL system and aero-optic effects on beam propagation from high and medium altitude platforms are examined. An overview of system capabilities details how the HEL system will be more difficult to incorporate into legacy strike aircraft, but may be feasible for future aircraft such as the JSF. Tactical flight simulations are used to study and develop potential concepts of operation (CONOPS), using realistic scenarios and threat environments. Results show that a tactical HEL will not be a stand-alone weapon in combat, but will have many potentially useful tactical applications. Another study of a high energy free electron laser (FEL) system aboard C-130J-30 Hercules shows that such a system is feasible. Finally, a study of the FEL shows that strong field extraction can be optimized using undulator tapering. / US Marien Corps (USMC) author.

A operação dinamicamente estável com zonas conjuntas foi obtida para um ressonador laser contendo dois bastões de Nd:YAG com módulos laser comerciais. O ressonador não polarizado gerou 115 W de potência no modo transversal fundamental TEM00. Quando polarizado por lâmina de Brewster atingiu 100,5W de potência de saída com 91% de polarização. Quando o ressonador foi polarizado com um polarizador de filme fino, obteve-se melhora na qualidade de feixe e um aumento na polarização, com o valor de M2 sendo 1,56 e 1,84 nas direções x e y respectivamente com 95,4% de polarização. A potência de saída foi, ao nosso conhecimento, a mais alta obtida para lasers polarizados operando no modo fundamental e usando módulos lasers comerciais de Nd:YAG bombeados lateralmente por diodos sem nenhuma preparação especial. / Dynamically stable operation with joined stability zones of a linearly polarized resonator is shown for a laser containing two diode side-pumped Nd:YAG rods with commercial laser modules. The unpolarised resonator provided 115 W of TEM00 output. When polarized by a Brewster plate, it reached 100.5 W of output power with 91% polarization. When the resonator was polarized by a thin film polarizer, an increase in beam quality was obtained with M2 values of 1.56 and 1.84 in the x and y directions, respectively with 95.4% polarization. The output power achieved is, to our knowledge, the highest reported for polarized, fundamental-mode lasers using commercial, diode side-pumped Nd:YAG modules without any special preparation.

Os lasers Raman permitem a exploração de novos comprimentos de onda, não comumente acessíveis, graças ao Espalhamento Raman Estimulado. Unidos a processos de conversão não linear, abrem-se campos para emissão de comprimentos de onda na região do visível no espectro eletromagnético. Com uma mesma configuração, diversas combinações de cristais possibilitam a geração de múltiplas frequências, transformando esse tipo de laser em um dispositivo compacto e barato quando comparado com outras tecnologias existentes. Este trabalho apresenta a busca da conversão intracavidade em frequências de lasers Raman, em uma configuração linear. Com dois comprimentos de onda de bombeamento de energia (797 nm e 872 nm), diodos semicondutores foram utilizados para acessar dois picos de absorção do cristal Nd:YLF. O bombeamento em 797 nm levou a emissão fundamental em 908 nm. E através do cristal KGW, com linhas de emissão Stokes, um novo comprimento de onda foi alcançado, em 990 nm. Com o cristal dobrador, BiBO, soma de frequência e segundo harmônico foram gerados, permitindo as emissões em uma região espectral azul bastante larga (450 500 nm). Com o bombeamento em 872 nm, uma emissão de três níveis no cristal Nd:YLF não foi possível, conseguindo apenas a emissão em 1064 nm, linha comum para cristais de neodímio. Uma outra cavidade foi estudada, porém com bombeamento em 880 nm e cristal de Nd:YVO4, conhecido por ser self-Raman. Com uma configuração linear semelhante à anteriormente citada, somente sua linha de emissão fundamental em 914 nm foi obtida, não sendo possível com as condições trabalhadas a emissão Stokes, que permitisse dar continuidade ao estudo. / The Raman lasers allow the exploration of new wavelenghts, not commonly avaliable, thanks to stimulated Raman scattering. Using non-linear convertion processes, the emission of wavelenghts in the region of the visible spectrum become possible. With the same cavity configuration, the use of different combinations of crystals allow the generation of multiple frequencies, transforming this type of laser in a compact and cheap device when compared to other existing technologies. This work presents our research for intracavity Raman conversion, in a linear cavity configuration. Two pumping wavelengths of 797 nm and 872 nm, supplied by semiconductor diodes were used to access two absorption peaks of the Nd: YLF crystal. The pumping at 797 nm led to fundamental emission at 908 nm. And through the KGW crystal, with Stokes shift of 901 cm-1, a new wavelength was obtained at 990 nm. With the doubling crystal, BiBO, sum frequency and second harmonic were generated, allowing the emissions in a fairly broad blue spectral region (450 - 500 nm). With the pumping at 872 nm, a three levels emission in the Nd: YLF crystal could not be obtained, achieving only emission at 1064 nm, a common line for Neodymium crystals. An another cavity was studied, but with pumping at 880 nm and using a Nd:YVO4 crystal, known for being self-Raman. With a similar linear configuration to the above mentioned, only its fundamental, three-level emission line at 914 nm was obtained.

Foi desenvolvida e construída uma cavidade bombeadora para um meio de ganho de Cr:LiSAF na forma de bastão, bombeado por duas lâmpadas, visando sua operação como amplificador de pulsos ultracurtos a taxas de repetição elevadas, e com redução da carga térmica sobre o meio de ganho. A cavidade e o meio de ganho foram caracterizados sob operação como laser e como amplificador de pulsos ultracurtos. Atuando como laser, obtivemos 30 Hz de taxa de repetição e 20 W de potência média, resultado inédito, e ganho máximo de 1,5 por passagem. Alterando as características do bombeamento, foi possível operar o laser a 8 Hz e 16 W de potência média, com ganho máximo de 3,6 por passagem. A cavidade bombeadora, na configuração de maior ganho, foi integrada e sincronizada a um sistema Chirped Pulse Amplification baseado em cristais de Ti:Safira, concebido e construído visando a sua conjugação com o amplificador de Cr:LiSAF. O amplficiador introduziu um fator de amplificação de 150 em pulsos de 20 ps, produzindo pulsos com potência de pico de 0,5 TW. Também foi apresentada uma nova técnica para medida do limiar de ablação por pulsos ultracurtos, e sua teoria analítica foi desenvolvida. Esta técnica foi utilizada na determinação do limiar de ablação de cristais de Cr:LiSAF no regime de 20 ps. / We have developed and built a pumping cavity for a Cr:LiSAF rod, pumped by two flashlamps, in order to operate it as an ultrashort laser pulse amplifier at the highest possible repetition rate, under reduced thermal load. The pumping cavity and the gain medium were characterized under laser and ultrashort pulse amplifier operation. Operating as a laser, 30 Hz repetition rate and 20 W average power were obtained for the first time at a maximum gain per pass of 1.5. Changing the pumping characteristics, the laser provided 16 W at 8 Hz repetition rate, at a maximum gain of 3.6. The cavity, in the highest gain configuration, was integrated and synchronized to a Ti:Sapphire Chirped Pulse Amplification system, conceived and built to comprise the Cr:LiSAF amplifier. The amplifier provided amplification by a factor 150 to the 20 ps stretched pulses, resulting in pulses with 0.5 TW of peak power. Also, a new technique to measure ultrashort pulses ablation threshold was presented, and its analytical theory was developed. This technique was used to determine the ablation threshold for Cr:LiSAF crystals in the 20 ps regime.

Chen Fei. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 86-92). / Abstracts in English and Chinese. / Acknowledgements --- p.i / List of publications --- p.ii / Abstract (In English) --- p.iii / Abstract (In Chinese) --- p.v / Table of contents --- p.vii / List of figures --- p.x / List of tables --- p.xiv / Chapter Chapter I --- Introduction --- p.1 / Chapter Chapter II --- Sol-gel channel waveguides --- p.6 / Chapter 2.1 --- General sol-gel process --- p.6 / Chapter 2.2 --- Dye-doped sol-gel zirconia and zirconia-ORMOSIL materials --- p.10 / Chapter 2.3 --- Fabrication of sol-gel channel waveguides --- p.15 / Chapter 2.3.1 --- General process of the photolithographic technique --- p.15 / Chapter 2.3.2 --- Channels in glass substrates by using photolithographic wet etching technique --- p.19 / Chapter 2.3.3 --- Channels in fused silica substrates by using photolithographic dry etching technique (Inductive-coupled plasma etching) --- p.24 / Chapter Chapter III --- Coupled-wave theory and experimental setup of distributed feedback channel waveguide lasers --- p.27 / Chapter 3.1 --- Coupled-wave theory of distributed feedback lasers --- p.27 / Chapter 3.2 --- Experimental setup --- p.33 / Chapter Chapter IV --- One-dimensional and two-dimensional optical waveguide analysis --- p.37 / Chapter 4.1 --- 1-D planar waveguide analysis --- p.37 / Chapter 4.2 --- 2-D channel waveguide analysis using the Marcatili method --- p.39 / Chapter 4.2.1 --- The Eypq modes: Polarization in the y direction --- p.42 / Chapter 4.2.2 --- The Eypq modes: Polarization in the x direction --- p.46 / Chapter 4.3 --- 2-D channel waveguide analysis using the effective index method --- p.48 / Chapter Chapter V --- Distributed feedback channel waveguide lasers tunable in the visible --- p.50 / Chapter 5.1 --- Rhodamine 6G-doped zirconia planar and channel waveguides --- p.51 / Chapter 5.2 --- Results and discussion --- p.56 / Chapter 5.3 --- Summary --- p.66 / Chapter Chapter VI --- Near infrared distributed feedback channel waveguide lasers --- p.68 / Chapter 6.1 --- LDS dye-doped zirconia-ORMOSIL planar and channel waveguides --- p.68 / Chapter 6.2 --- Results and discussion --- p.72 / Chapter 6.3 --- Summary --- p.80 / Chapter Chapter VII --- Summary --- p.81 / References --- p.86

by Tong Wai Yin Alex. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references (leaf 55). / by Tong Wai Yin Alex. / Acknowledgement / Biographical Sketch / Abstract / Table of contents / Chapter Chapter 1 --- Introduction --- p.1 / Chapter Chapter 2 --- Nonlinear Optics in dye-doped solid --- p.4 / Chapter 2.1 --- Nonlinear Optics --- p.4 / Chapter 2.2 --- Photophysics of dye molecules --- p.6 / Chapter 2.3 --- Nonlinear effect in dye-doped solid --- p.8 / Chapter Chapter 3 --- Sol-Gel Silica --- p.11 / Chapter 3.1 --- The formation of dye-doped sol-gel silica --- p.11 / Chapter 3.2 --- The physical properties --- p.15 / Chapter 3.3 --- The optical properties --- p.16 / Chapter Chapter 4 --- Saturation Absorption --- p.18 / Chapter 4.1 --- Saturation Absorption in Fluorescein 548 dye-doped solid --- p.18 / Chapter 4.2 --- Experimental Details --- p.19 / Chapter 4.3 --- Results and Discussion --- p.19 / Chapter 4.4 --- Conclusion --- p.30 / Chapter Chapter 5 --- Optical Phase Conjucation --- p.31 / Chapter 5.1 --- OPC Theory --- p.31 / Chapter 5.11 --- The Distortion Correction Theorem --- p.32 / Chapter 5.12 --- The Proof of the Distortion Theorem --- p.32 / Chapter 5.13 --- The generation of Phase Conjucate Waves --- p.34 / Chapter 5.2 --- Degenerate Four Wave Mixing --- p.35 / Chapter 5.21 --- Geometries of DFWM --- p.35 / Chapter 5.22 --- DFWM Theory --- p.37 / Chapter 5.23 --- DFWM in Absorbing Media --- p.40 / Chapter 5.3 --- Experimental Details --- p.44 / Chapter 5.4 --- Results and Discussion --- p.46 / Chapter 5.5 --- Conclusion --- p.53 / Chapter Chapter 6 --- Conclusion and Suggestions for future work --- p.54 / Reference

Wang Jun. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 74-79). / Abstracts in English and Chinese. / Acknowledgements --- p.i / List of publications --- p.ii / Abstract (In English) --- p.iii / Abstract (In Chinese) --- p.v / Table of contents --- p.vii / List of figures --- p.x / List of tables --- p.xiv / Chapter Chapter I --- Introduction --- p.1 / Chapter Chapter II --- Dye-doped sol-gel zirconia and zirconia-organically modified silicate waveguides --- p.6 / Chapter 2.1 --- General sol-gel process --- p.6 / Chapter 2.2 --- Dye-doped sol-gel zirconia and zirconia-ORMOSIL waveguides --- p.7 / Chapter Chapter III --- Basic theory and experiment setup of distributed feedback waveguide lasers --- p.13 / Chapter 3.1 --- Coupled-wave theory of distributed feedback lasers --- p.13 / Chapter 3.2 --- Introduction on the theory of planar optical waveguide --- p.16 / Chapter 3.3 --- Experiment setup design of DFB waveguide lasers --- p.19 / Chapter Chapter IV --- Zirconia and zirconia-organically modified silicate distributed feedback waveguide lasers tunable in the visible --- p.23 / Chapter Chapter V --- Tunable multi-wavelength distributed feedback zirconia waveguide lasers --- p.35 / Chapter 5.1 --- Brief introduction on multi-wavelength lasers --- p.35 / Chapter 5.2 --- R6G-doped zirconia multi-mode waveguides --- p.36 / Chapter 5.3 --- Experimental results and discussion --- p.39 / Chapter 5.3.1. --- Dual- and quadruple-wavelength DFB waveguide lasers --- p.39 / Chapter 5.3.2. --- The dispersion characteristics of multi-wavelength DFB waveguide lasers --- p.44 / Chapter 5.3.3. --- Determination of waveguide parameters by the DFB technique --- p.48 / Chapter 5.4 --- Summary --- p.51 / Chapter Chapter VI --- Distributed feedback laser action in sol-gel glass symmetric waveguides --- p.53 / Chapter 6.1 --- The fabrication of dye-doped glass symmetric waveguides --- p.54 / Chapter 6.2 --- Experimental results and discussion --- p.56 / Chapter 6.2.1. --- DFB laser action in sol-gel glass symmetric-asymmetric waveguide --- p.56 / Chapter 6.2.2. --- Dispersion characteristics of DFB symmetric and asymmetric waveguide lasers --- p.61 / Chapter 6.3 --- Summary --- p.65 / Chapter Chapter VII --- Summary --- p.69 / References --- p.74