Researches Of High-repetition LDA Pumped Nd:YAG Ceramic Laser

In the field of solid state laser, Nd:YAG ceramic is another fine laser material after Nd:YAG single crystal, which breaks through the limitation of Nd:YAG single crystal unceasingly with the strong tendency of replacing the latter one and has been the focus for considerable researchers all over the world in recent years. Thereby, on the basis of studying the LDA side-pumped Nd:YAG single crystal laser, the following dissertation mainly researches the Nd:YAG ceramic crystal and Nd:YAG ceramic laser. The content as follows:We investigated and summarized the history of development, status quo of study, characteristics and application about the LDA side-pumped Nd:YAG single crystal laser and LDA side-pumped Nd:YAG ceramic laser. In addition, we introduced the basic theory of the Q-switched and the frequency doubling of the solid state laser, and designed the laser head and the cooling system of the LDA side-pumped Nd:YAG laser, then the purpose of miniaturizing of laser head and the quick cooling, high efficiency of the cooling system was carried out.On the basis of measuring thermal focal length of the LDA side-pumped Nd:YAG laser in the experiment, we designed the appropriate resonant cavity, then by means of traditional Q-switched methods of glan prism and KD*P crystal, the high-repetition Q-switched Nd:YAG single crystal and Nd:YAG ceramic laser were studied respectively. Finally, the conclusion is that Nd.YAG ceramic laser has almost the same insertion loss and output performance compared with Nd:YAG single crystal laser under the identical experimental condition.We adopt the dual-polarization electro-optic Q-switched technique to the Nd:YAG ceramic laser for the first time, and achieve the better results than traditional single polarization electro-optic Q-switched technique, which not only reduce the insertion loss of the Q-switched device but also increase the laser output energy in a big extent and compensate the thermal birefringence loss caused by the high-repetition Q-switched Nd:YAG ceramic laser effectively. The result in the experiment indicates:because of the adoption of dual-polarization electro-optic Q-switched technique, the insertion loss of the Q-switched device is decreased by 17%, the laser output energy is improved by 43% and the dynamic-static ratio is increased by 5.7%.According to the film system theory of laser resonant cavity, the reasonable film parameters were analyzed and designed, then by using of KTP crystal type II phase-matching intracavity frequency-doubling and inserting dispersion prism in the resonant cavity, the Nd:YAG ceramic laser operating at the single wavelength of 660nm was realized. On the basis of design of the film system in the single wavelength of 660nm Nd:YAG ceramic laser, the folded cavity parameters were optimized using the software of Matrixlaser, then by means of LN crystal electro-optic Q-switched and KTP crystal type II phase-matching intracavity frequency-doubling, the Nd:YAG ceramic laser at 670nm wavelength was carried out eventually. At present, there are not any reports on the electro-optic Q-switched Nd:YAG ceramic laser at 670nm wavelength.The adoption of cavity reflector coating selective dielectric film, the simultaneous output of dual wavelength of 1064nm and 1319nm were realized for the first time, then the truth that the Nd:YAG ceramic may achieve the simultaneous output of dual wavelength laser was confirmed.At present, the study on LDA side-pumped Nd:YAG laser, especially LDA side-pumped Nd:YAG ceramic laser becomes to be one of the focuses in the word. The further research in the field is going to establish the technological foundation for the development of high-repetition and high power ceramic solid state laser, and has important application value.