【作者】 马建立；

【导师】 端木庆铎；

【作者基本信息】 长春理工大学 ， 物理电子学， 2010， 博士

【摘要】 高光束质量激光器在科学研究、信息通信、工业加工、医疗卫生、国防军事等领域有极为广阔的应用。基模光束是高光束质量的极限,如何获得高功率基模光束激光是DPL领域的研究热点,基模光束实现稳定倍频可以扩展DPL(diode pumped laser)的应用范围。本论文主要针对DPL的光束质量控制技术和稳定倍频技术展开研究。研究包括：腔内光束的控制；晶体产热和热源分布的控制；影响高重频调Q脉冲稳定性的因素；高效率双程放大技术和稳定倍频技术。重点研究了以下几方面内容：DPL腔内光束控制技术研究。用透镜和谐振腔的腔镜组成大基模体积腔型,配合五围错位泵浦Nd:YAG模块,研究获得了宽动态范围的基模输出,单模块最高输出61W、双模块最高输出124W,光束质量因子M2<1.5。采用VCSEL端面泵浦Nd:YVO4薄片晶体,实现了平均功率66mW的激光输出。DPL的生热控制技术研究。通过控制晶体中生热量和生热路径的手段实现端面泵浦高功率基模激光器：采用887nm激光泵浦Nd:YVO4晶体,延长了泵浦光吸收路径,获得22W基模激光,对应的光-光转换效率为71.2%,并可在100kHz调Q下稳定工作,脉冲宽度96ns；多模运转可输出42.3 W,光-光转换效率72.2%。此外,采用913nm泵浦Nd:GdVO4晶体,将Nd:GdVO4的泵浦光和振荡光能量差降到最低,实现低热高效率运转的基模激光器：在吸收4.30W泵浦光下输出3.32W激光,对应的光-光转换效率和斜率效率分别高达77.2%和81.2%。高重频稳定调Q基模光束振荡器的设计。用881nm激光泵浦Nd:YVO4晶体,获得了平均功率11.3W、高重频100kHz稳定调Q、脉冲宽度30.2ns的基模激光,光-光转换效率和斜率效率分别是67.3%和73.7%,并针对该激光器研究了高重频调Q的稳定性问题。激光放大及稳定倍频技术研究。采取独特的光路设计研究了端泵Nd:YVO4的双程放大特性,在注入16.8W泵浦功率下,对0.5W可以放大16倍；11.3W振荡光做抽取时,得到21.7W的输出,抽取效率高达62%；并对放大后的激光做倍频研究,得到不稳定度小于±2%的532nm激光,倍频效率为44.7%。更多还原

【Abstract】 High beam quality lasers have been broadly applied in the field of scientific reaseach, information communication, industrail processing, health care and national defense and military. How to obtain high power foudamental mode laser beam was deemed as a difficult point in DPL. Using foundamental mode laser beam, the application of DPL could be extended by frequency doubling with stablity. The present paper mainly focuses on the reasearch of beam quality control and stable frequency doubling, the reasearch including intra-cavity beam control, controlling the heat generated by crystal and heat distribution, factors influncing Q switched pulses with high repeating frequency, high efficiency double pass amplifier and stable frequency doubling. The obtained results are as follow:Reaseach on intra-cavity beam control:a large volume cavity for foudamental mode was realized by combining lens and resonator, and wide dynamic range foudamental mode output was obtained, with the maximum output power of 61W by single module and 124w by double modules and beam quality factor M2<1.5. By VCSEL sidepumping Nd:YVO4 thin slice, an average power of 66mW laser output was obtained.Reasearch on the control of heat generated by DPL:a sidepumped high power foudamental mode laser was realized by means of controlling the generated heat and the route of heat radiation. By using 887nm light to pump Nd:YVO4 crystal, the pump absorption route was extended and 22w foudamental mode laser was obtained. Further,100kHz modulated stable reasonace was realized with pulse width of 96ns and light-light conversion efficiency of 71.2%, on the other aspect,42.3w output and light-light conversion efficiency of 72.2% was realized under the multimode operation. Moreover,913nm light was used to pump Nd:GdVO4 in order to reduce the difference between pump light and resonating light, as a result, a high efficiency foudamental mode laser generating fewer heat was realized.3.32w output energy was obtained by absorbing 4.30w pump light and the corresponding light-light conversion efficiency and slop efficiency were 77.2% and 81.2% respectively.Design of stable Q swithed foudamental mode resonator with high repeating frequency: using 881nm pump light to pump Nd:YV04 crystal, foudamental laser beam with average power of 11.3w,100kHz stable Q switched output and pulse width of 30.2ns was obtained. The light-light conversion efficiency and slop efficiency were 67.3% and 73.7% respectively, and the stability of the high repeating frequency Q swithed laser was also studied.Reasearch on laser amplification and stable frequency doubling:the double pass amplification charateristics of sidepumped Nd:YVO4 was studied by using a particularly designed beam path.In the case of 16.8w pump power, incident laser of 0.5w can be ampified to 16 times larger, and 21.7w output was,obtained by extracting 11.3w resonating light, resulting a 62% extraction efficiency. Further, a frequency doubling reasearch for the amplified laser was performed, and 532nm output with unstablity less±2% was obtained, resulting a doubling frequency of 44.7%.更多还原