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The Research Of LD End-Pumped AO Q-Switched Nd:GdVO4 Laser With High Repetition Rate

Posted on:2007-05-07Degree:MasterType:Thesis
Country:ChinaCandidate:Z F LeiFull Text:PDF
GTID:2178360212966781Subject:Physical Electronics
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Laser-diode pumped solid-state laser (DPSSL) has advantages of compactness, good stabilization, high efficiency and long lifetime. Pumping with a high power LD and with a Q switching technology, laser pulse with the characteristics of high repetition rate, high peak power and shot pulse width, will be obtained. This is widely used in fields of radar, laser range and laser remote sensing. While as a laser medium has excellent characteristics of high thermal conductivity,larger emission cross-section and higher absorption coefficient, moderate upper state lifetime and polarized laser output, Nd:GdVO4 crystals are more suitable for Q switch laser with high repetition rate and peak power output. Now, scientists have become more interest in this topic.This paper developed with the purpose of obtaining laser output that has high peak power, short pulse width and small divergence angle. From the four-level rate equation, we deduced threshold power and slope efficiency for continuous laser output; it is the foundation for experiment. We also deduced the peak power, laser pulse energy and pulse width for the Q switch laser, and optimized the Q switch theory.We analyzed the property of LD spectrum and light distribution on cross section. Then, we found that light distribution on cross section is fit for Gauss distribution, but the wavelength is lower than Nd:GdVO4 crystals'absorption peak(808nm), and it will move towards to 808nm while rising temperature or increasing the output power, and we had discussed its influence in the experiment.Firstly, we perform experiments for continuous laser output and Q switch laser output on a one end pumped flat-flat cavity setup. In the continuous laser output experiment, we study many factor influencing on output power such as cavity length, working temperature and output mirror transmission. When the pumping power is 30.6W, the continuous output power is 8W, slope efficiency is 30.3%. In the Q switch experiment, we study many influencing factor for laser pulse width including cavity length, working temperature and output mirror transmission, and analyze the result with the former Q switch theory. When the repetition rate is 10kHz and incident power is 16.8W, the output power is 3.1W, and the optimally pulse width is...
Keywords/Search Tags:DPSSL, Nd:GdVO4 crystal, acousto-optic Q-switched
PDF Full Text Request
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