Research Of Control Technology Of Passively Q-switched Laser Output Characteristics

In recent years, high power diode pumping solid-state lasers have become a hotspot for research and development in the field of international new type of solid-state laser for their advantages of unique merits, such as long useful time, compact structure, and high efficiency and so on. What kind of the pump source adopted in this type of diode laser is semiconductor laser which can greatly improve the overall efficiency and reliability of the lasers and make the quality of the beam better. Therefore the research on high power diode pumping solid-state lasers is regarded as revolution in the laser history.With the improvement and development of high power diode lasers, main researches of domestic scholars have paid more attention to the high power of DPSSL. It can be predicted that high power will become one of the new type lasers with rapid development and much potentiality in the world.In the application of laser technology, related laser technologies, such as laser radar, pulse laser range finder have been greatly promoted under the production and development of Q-switch technology. This thesis is to make a research to the high repetition frequency Q-switch system in LD pumped solid laser, summarize the research status and development of Q-switch laser and discuss typical study on Nd3+:YAG..The thesis will also make a study to the fundamental principles of crystals when they are working continuously. Based on the study, experiment structure is established and the output property of continuous pumped lasers is studied. Considering the real circumstances that the off-axis pumping may exist, the thesis makes research on the effects that off-axis magnitude produce on the laser's output property. The research indicates that the output property of lasers will become poor with the increase of off-axis volume.The thesis also makes a comparison to several main kinds of Q-switch technologies and states the theory of relaxation oscillation, properties of Cr4+:YAG and saturation property. Based on the research, the paper will analyze and discuss the Cr4+:YAG and passively Q-switched laser according to rate equations. Then the experimental framework of the passively Q-laser end pumping will be constructed. The thesis will also make an experimental study on Cr4+:YAG passively Q-switch Nd3+:YAG laser. It put much emphasis on the effects that the factors, such as, the pump power, cavity length and transmittance of output mirror, produce on the repetition rate of the laser's output pulse sequence, pulse width and output power.The paper wants to achieve the purpose of actively controlling the feasibility of passive Q-Laser from the theoretical analysis according to working principles of passive Q-laser, that is, through the added LD the thesis aims to achieve the active controlling to the parameters of repetition frequency of passive O-laser output pulse, pulse width and on-off switch.