增益开关型Cr～（4+）：Mg₂SiO₄激光器和Cr～（4+）：YAG激光器的研究

【作者】 苏娅菲；

【导师】 王加贤；

【作者基本信息】 华侨大学 ， 物理电子学， 2004， 硕士

【摘要】 随着掺Cr⁴⁺激光材料的不断出现和器件的成功运转，掺Cr⁴⁺激光材料及其器件的研究已经成为固体可调谐激光器研究的热点之一。尤其是Cr⁴⁺：YAG和Cr⁴⁺：Mg₂SiO₄这两种晶体有望成为近红外可调谐固体激光器的理想增益介质，所以对它们的研究尤为重要。本文采用理论和实验相结合的方法，研究了Cr⁴⁺：YAG和Cr⁴⁺：Mg₂SiO₄二种晶体作为增益介质的增益开关型Cr⁴⁺：YAG和Cr⁴⁺：Mg₂SiO₄激光器的时间特性。 第一章：综述了掺Cr⁴⁺离子的激光材料特性，特别是Cr⁴⁺：YAG和Cr⁴⁺：Mg₂SiO₄晶体的重要特性以及在激光器件中的应用和国内外研究概况。 第二章：采用Nd：YAG调Q激光脉冲作为泵浦源，实现Cr⁴⁺：Mg₂SiO₄激光器的增益开关运转，得到中心波长为1.25μm，能量为0.4mJ，脉宽32ns的激光脉冲输出。从速率方程出发，对Cr⁴⁺：Mg₂SiO₄激光器的增益开关时间特性进行理论分析，计算出脉冲宽度，理论结果和实验结果基本一致。 第三章：对三镜腔的腔结构进行了理论研究，从高斯光束的传输理论出发，运用ABCD定律得到优化的折叠角，补偿了三镜腔的象散，从而保证晶体和输出镜上光束为高斯基模，并且计算腔的稳定条件。采用1.06μm激光脉冲泵浦三镜腔Cr⁴⁺：YAG激光器，得到能量和脉宽分别为0.46mJ和28ns的中心波长为1.44μm的调Q脉冲输出。 第四章：设计了一个复合腔，使Cr⁴⁺：YAG既作为可饱和吸收体对1.06μm激光调Q，同时又作为激光增益介质产生1.44μm激光，得到1.06μm和1.44μm双波长双调Q激光输出。1.06μm和1.44μm激光脉冲的能量和脉宽分别为6.8mJ、38ns和0.04mJ、21ns。理论上根据Cr⁴⁺：YAG激光器的相关参数，计算了1.44μm激光的脉宽，理论结果和实验结果基本一致。更多还原

【Abstract】 With the development of the Cr -doped crystals and the successful working of pertinent lasers, the study of them has become one of the hot pots of the study of the solid tunable lasers. These two crystals such as Cr4+:Mg2SiO4 and Cr4+:YAG will hopefully become the ideal gain medium of tunable lasers in the near infrared wavelengths, and the study of them will be the most important. With the theoretical and experimental methods, the paper studies the time characteristics of gain-switched Cr4+:YAG and Cr4+:Mg2SiO4 laser.Chapter 1: The paper appraises the laser characteristics of Cr4+ ions in several garnet host crystals, especially the important characteristics and the application in laser devices of Cr4+:YAG and Cr4+:Mg2SiO4 and the general research situation.Chapter 2: Pumped by 1.06um Q-switched Nd:YAG laser, gain-switching of Cr4+:Mg2SiO4 laser is realized. And the output energy and the pulse width of the central wavelength of 1.25 um are 0.4mJ, 32ns. By studing the time characteristics of gain-switching of Cr4+:Mg2SiO4 laser with the rate equations theoretically, we calculate the formulas of the pulse width, and the theoretical parameters are consistent with the experimental results approximately.Chapter 3: A theoretical study is devoted to the parameters of the three-mirror cavity. By using ABCD ray transmission matrix, an optimized folding angle is obtained to compensate astigmatism, so. that the beam of the output mirror is ensured to be Guass basic mode, and the stable condition is calculated. Using 1.06um Nd:YAG laser pumping the three-mirror cavity Cr4+:Mg2SiO4 laser, the output energy and the pulse width of the gain-switched 1.44 um laser are 0.46mJ, 28ns.Chapter 4: The dual-wavelength laser is achieved of 1.06um and 1.44um in the designed compound resonator. The Cr4+:YAG is operated as a saturable absorber and a gain medium simultaneously. The output energy and the pulse width of 1.06 um and 1.44um are 6.8mJ, 38ns and 0.04mJ, 21ns respectively. By using the pertinent parameters of Cr4+:YAG crystal, the pulse width of 1.44 um are analyzed theoretically and the results are consistent with the experimental data.更多还原