产生钠导引星星群的钠信标激光合/分束技术  

Beam combining/splitting technology of sodium beacon laser for generating sodium guidestars constellation

作　　者：卞奇 薄勇[1,2] 左军卫 彭钦军[1,2] Bian Qi;Bo Yong;Zuo Junwei;Peng Qinjun(Center for Laser Physics and Technique,Technical Institute of Physics and Chemistry,Chinese Academy of Sciences,Beijing 100190,China;Institute of Optical Physics and Engineering Technology,QiluZhongke,Ji’nan 250000,China)

机构地区：[1]中国科学院理化技术研究所激光物理与技术研究中心,北京100190 [2]齐鲁中科光物理与工程技术研究院,济南250000

出　　处：《强激光与粒子束》2023年第4期124-129,共6页High Power Laser and Particle Beams

基　　金：国家自然科学基金项目(62005295);国家重点研发计划项目(2016YFB0402103)。

摘　　要：研究了脉冲光束的偏振和时序非相干合成技术,通过偏振合束器将两路50 W级500 Hz的589 nm钠信标激光在空间上合为一束光线,成功突破了100 W级μs脉冲全固态钠信标激光输出;利用脉冲激光同步延时器控制两路激光脉冲的时序,使其按先后顺序合成一束脉冲激光,重复频率提升到1 kHz。合束后的激光光束质量M2约为1.41,与单光束的光束质量基本保持一致,光斑抖动性约为40μrad,可满足激光钠导引星自适应光学系统的应用需求。与传统的相干合成方法相比,该偏振和时序非相干合成方案具有结构简单、稳定、效率高的优点,且整个系统无需复杂的相位控制机制,为脉冲激光功率扩展提供了新途径。基于上述技术基础,结合自主提出的精密偏振分光专利技术,在丽江天文台通过一台发射望远镜将四束25 W/束的μs脉冲黄激光发射到钠层,成功产生了四颗钠导引星,这一结果将有助于推动大型地基光学望远镜中多层共轭自适应光学技术的发展。A polarization and sequence incoherent combining technology of pulsed laser beam is introduced.A 100 W level microsecond-pulse all-solid-state sodium beacon laser is performed,via combining two independent 50 W level 589 nm lasers at 500 Hz to be one beam by a polarized coupler.Through a pulsed laser synchronizing and delay controller,the two pulsed laser beams are added successfully at time sequence,and the corresponding repetition rate is up to 1 kHz.The beam quality factor M2 of the combined laser is about 1.41,maintaining at almost equal level with one of two laser beams,and the beam pointing stability is measured to be about 40μrad,which can well meet the requirements at the time of laser guide star testing.Compared with the coherent beam combining,the approach of polarization and sequence incoherent combining has high efficiency,simple combination,and no specific restriction on phase and frequency spectrum,providing a new way for pulsed laser power scaling.Based on a self-proposed precise polarized splitting technology,four beams of(25 W/beam)μs-pulsed yellow laser are projected up to the sodium layer through one launching telescope at Lijiang Observatory,and successfully generate four sodium guidestars,which could promote the development of multi-conjugate adaptive optics systems on large-aperture ground-based telescopes.

关 键 词：钠信标激光 非相干光束合成 偏振调制 时序控制 脉冲激光器 

分 类 号：O437[机械工程—光学工程]