高平均功率腔倒空纳秒薄片激光器  

Cavity-Dumped Nanosecond Thin-Disk Laser with High Average Power

作　　者：戴隆辉 刘锐[1] 公发全[1] 李想 邓淞文[1] 贾勇[1] 金玉奇[1] 李刚[1] Dai Longhui;Liu Rui;Gong Faquan;Li Xiang;Deng Songwen;Jia Yong;Jin Yuqi;Li Gang(Key Laboratory of Chemical Lasers,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian,Liaoning 116023,China;University of Chinese Academy of Sciences,Beijing,100049,China)

机构地区：[1]中国科学院大连化学物理研究所化学激光重点实验室,辽宁大连116023 [2]中国科学院大学,北京100049

出　　处：《中国激光》2021年第13期29-38,共10页Chinese Journal of Lasers

基　　金：大连市科技创新基金(2018J11CY013)。

摘　　要：基于自主研制的24通薄片泵浦模块,开展了高重复频率、窄脉宽、高光束质量的腔倒空激光技术研究。首先,基于朗伯-比尔定律,计算了不同厚度的薄片晶体的吸收效率和泵浦多通数之间的关系;其次,基于准三能级速率方程,计算了阈值泵浦功率、连续输出功率与输出镜透过率的关系,并对腔倒空谐振腔中光子数密度随时间的变化规律进行了研究。最后,采用该多通泵浦模块进行了连续出光实验,获得了输出功率为94.1 W的1030 nm连续p偏振激光输出,其光-光转化效率为52.28%,斜率效率为60%,光束质量为Mx2=2.05,My2=1.93的基模输出;不改变腔型结构,插入普克尔盒和1/4波片,获得了脉冲宽度为7.43 ns,重复频率为100 kHz的1030 nm脉冲输出,平均输出功率为65.4 W,光-光效率为36.33%,斜效率为45%,光束质量Mx2=2.37,My2=2.20。Objective Laser-matter interaction research using nanosecond pulse lasers has resulted in industrial applications, such as laser processing, laser marking, and laser cleaning, because of its advantages of moderate cost and high reliability. The repetition rate is an important indicator to describe the number of laser pulses per unit time. The higher the repetition frequency, the more the number of working pulses per unit time. Thus, high-quality processing results can be obtained via high-speed and high-precision processing using nanosecond pulse lasers. Therefore, development efforts in this field focus on achieving a narrow pulse width, high average power, and high repetition rate. With the increase in pump power, traditional lasers such as fiber lasers have strong nonlinear effects, such as stimulated Brillouin scattering and backscattering, resulting in a wider output pulse width;however, the peak power obtained is limited. Because of the radial distribution of the heat generated by the laser rod and the uneven temperature distribution, the radial temperature gradient will cause a serious thermal lens effect, which will affect the high power output and beam quality of the nanosecond laser. The emergence of thin-disk lasers has effectively improved this situation, wherein multipass pump technology is used to compensate for the considerably low single-pass absorption of the gain medium. The ingenious pump method improves its pump absorption efficiency, while the single-sided pumping back cooling method further reduces the thermal lens effect of the crystal, making it widely used in continuous and nanosecond pulse fields.Methods A cavity-dumped laser based on an independently developed 24-pass thin-disk pump module was investigated with a high repetition rate,narrow pulse duration,and high beam quality.First,the relationship between media absorption and the number of pump passes was calculated according to the Beer-Lambert law.Then,using the quasi-three-level rate equations,the dependence of the threshold pump p

关 键 词：激光器 薄片激光器 腔倒空 多通泵浦 重复频率 光束质量 

分 类 号：TN248[电子电信—物理电子学]