激光二极管抽运Cr^4＋：Nd^3＋：YAG自锁模自调Q激光器  

Laser Diode-Pumped Self-Mode-Locking Laser with a Self Q-Switched Cr^(4+):Nd^(3+):YAG Laser

作　　者：张海鹍[1] 陈秀峰[2] 王培吉[1] 张中士[1] 赵圣之[3] 杨克建[3] 相方超[1] 

机构地区：[1]济南大学理学院,山东济南250022 [2]中材高新材料股份有限公司,山东淄博255000 [3]山东大学信息科学与工程学院,山东济南250100

出　　处：《光学学报》2009年第3期738-742,共5页Acta Optica Sinica

基　　金：国家自然科学基金(60578010);济南大学科研基金(XKY0717)资助项目。

摘　　要：采用光纤耦合半导体激光抽运,实现了Cr^(4+):Nd^(3+):YAG自锁模白调Q激光器1.06μm激光输出。当抽运功率超过阈值2.83 W时,激光器便运转在调Q锁模状态,其锁模调制深度达到80%以上。当抽运功率最大为5.72 W时,平均输出功率为233 mW,相应调Q包络的单脉冲能量为16.5μJ,调Q包络的脉冲宽度大约为120 ns。调Q包络中锁模脉冲之间的间隔为2.8 ns,这与光子在谐振腔内的往返时间相一致,对应的重复率为357 MHz,锁模脉冲宽度估计为560 ps。利用双曲正割函数,考虑腔内光子数密度的空间高斯分布、增益介质的受激辐射寿命和饱和吸收体的激发态寿命对激光特性的影响,建立了描述Cr^(4+):Nd^(3+):YAG晶体自调Q自锁模动力学过程的速率方程组。数值求解该方程组,与实验结果符合较好。Simultaneous self-mode-locking and self-Q-switching in a laser diode-pumped Cr^4＋ ： Nd^3＋ ： YAG laser is presented. More than 80 % modulation depth of self-mode-locking has been achieved at the threshold pump power. A maximum average output power of 233 mW was generated at the maximum incident pump power of 5. 72 W, corresponding to a maximum pulse energy of 16.5 gJ for a single self-Q-switched pulse. The typical Q-switched envelope duration containing the mode-locked pulse trains was found to be around 120 ns and the repetition rate for the self-mode-locked pulse trains within the self-Q-switched pulse envelope was about 357 MHz. The width of the self-mode-locked pulse was estimated to be less than 560 ps. Using a hyperbolic secant function method, we introduced a rate equation model not only considering the Gaussian distribution of the intracavity photon density and the influences of the continuous pump rate, but taking into account the stimulated radiation lifetime of the active medium as well as the excited-state lifetime of the saturable absorber. Numerically solving the set of equation, the theoretical calculations are in good agreement with the experimental results.

关 键 词：激光器 自锁模 自调Q Cr^4+:Nd^3+:YAG晶体 速率方程 

分 类 号：TN248.1[电子电信—物理电子学]