内置透镜平平腔自调Q激光器的特性研究

Research on Self-Q-switch Laser with Internal Lens in Plano-plano Resonator

文章在Cr4+∶Nd3+∶YAG自调Q激光器中,实验验证了内置透镜平平腔组成的等效腔具有比普通平凹腔更高的稳定性,并给出相应理论解释;实验中还观察到在泵浦功率增加时,输出功率、重复频率呈现极值特性和单脉冲能量增加近两倍等特殊实验现象。本文通过理论分析指出,引起基模光束半径和泵浦速率的动态变化主要影响因素是晶体内热透镜效应,且可通过调节腔长、内置透镜的位置等方式改变输出激光的重频、能量特性。这说明在自调Q激光器方面,内置透镜平平腔比普通平凹腔具有更大的设计灵活性。

In this paper, it has been experimentally verified that the piano-piano resonator with internal lens behaves steadier than piano-concave resonator in an Cr^4＋ ：Nd^3＋：YAG self-Q-switch laser. And also, some especial phenomenon, such as the extremum properties of both the output power and repetition-rate along with pumping power increasing,is observed. By theoretical analysis, the major reason of extremum properties is explained by the dynamical variation of both the pumping rate and the radius of foundational-mode laser beam, which are excited by thermal lens effect in laaer crystal. Furthermore, by adjusting resonator length, focus-length and location of internal lens, the output charaetera of laser would be changed, which means that the piano-piano resonator represents more design-flexibility than piano-concave resonator in self-Q-switch laser.