声光调Q CO_2激光器的实验研究  

Experimental researches on acousto-optic Q-switched CO_2 laser

作　　者：何洋[1] 陆君[2] 陈飞[1] 李殿军[1] 郑长彬[1] 谢冀江[1] 郭劲[1] 

机构地区：[1]中国科学院长春光学精密机械与物理研究所激光与物质相互作用国家重点实验室,吉林长春130033 [2]第二炮兵装备研究院,北京100085

出　　处：《红外与激光工程》2015年第8期2280-2285,共6页Infrared and Laser Engineering

基　　金：中国科学院长春光学精密机械与物理研究所创新项目(Y25632C120);激光与物质相互作用国家重点实验室自主基础研究课题(SKLLIM1413)

摘　　要：为满足13.5 nm极紫外光刻（EUVL）等领域的应用需求,研制了高重复频率、高稳定性的声光调Q CO2激光器。首先,对声光Q开关的工作原理进行了分析,并实验研究了调制信号电压与衍射效率的关系。接着,研究了调制信号占空比对脉冲波形的影响,通过选择适当的占空比消去了脉冲拖尾。然后,对不同重复频率下的脉冲宽度、功率和脉冲幅值稳定性进行了测量和分析。最后,对激光器的光束指向稳定性进行了测量。实验结果表明：该激光器实现了重复频率1～100 k Hz连续可调的脉冲输出,在重复频率1 k Hz时,获得最小脉冲宽度252 ns和最大峰值功率7 579 W的激光脉冲输出。通过设计以殷钢管为主体的支撑架,使得激光器的脉冲幅值不稳定性小于3%,光束指向稳定性为46.6μrad。该声光调Q CO2激光器可作为高性能种子源在EUVL等领域中得到应用。In order to meet the demand of 13.5-nm extreme ultraviolet lithography （EUVL）, an acousto- optically Q-switched CO2 laser was developed, which has high repetition rate and high stability. First, the operating principle of the acousto-optic Q-switch was analyzed and the relationship between the voltage of modulated signal and diffraction efficiency was researched experimentally. And then, by studying the influence of modulated signal duty cycle on pulse waveform, the appropriate duty cycle was chosen to eliminate the pulse tail. Under the conditions of different repetition rates, pulse duration, power and the pulse amplitude stability were measured and analyzed. Finally, the beam pointing stability of the laser was measured. Experimental results indicate that the range of pulse repetition rate can be adjusted from 1 kHz to 100 kHz. When the repetition rate is 1 kHz, the minimum pulse duration is 252 ns and the maximum peak power reaches 7 579 W. By designing the support frames mainly made of invar steel, the unstablity of pulse amplitude is less than 3% and the beam pointing stability is only 46.6μrad. This acousto-optic Q-switched C02 laser is suitable for a seed source used in EUVL.

关 键 词：CO2激光器 声光调Q 重复频率 稳定性 

分 类 号：TN248.2[电子电信—物理电子学]