Cr (4 +): Yag Passively Q-switched Microchip Laser Output Pulse Characteristics

LD-pumped passively Q-switched microchip laser has many merits, such as allsolid-state, structure compactness, high repetition rate, and short pulse width,compared with traditional solid laser. The output laser with high repetition rate andshort pulse width is of great interest in the fields of remote ranging, 3-dimensionalimaging, and environmental monitoring. Therefore, it has been the research focustoday. Based on analyzing the performance processing of Cr4+:YAG passiveQ-switching, output laser characteristic and its stability of LD-pumped Cr4+:YAGpassively Q-switched microchip is mainly investigated, theoretically andexperimentally.The main research works and achievements are listed below:1. Output laser characteristic of CW LD-pumped Cr4+:YAG passively Q-switchedmicrochip, is investigated theoretically and experimentally. Research resultsshow that, ratio of gain and loss in the cavity, after opening the Q-switch, is themain factor of effecting output laser characteristic.2. Output laser stability of CW LD-pumped Cr4+:YAG passively Q-switchedmicrochip, is investigated theoretically and experimentally. Research resultsshow that, the uncertainty of switching time and rate is the main reason ofeffecting output laser stability.3. For improving the output stability, pre-pumping technology is presented andanalysed. Research results show that, uncertainty of switching time and rate isreduced, and stability of output laser is increased, after using pre-pumpingtechnology.