基于铌酸锂晶体的光束精密指向控制技术研究(特邀)  

Precise Beam Pointing Control Technology Based on Lithium Niobate Crystal(Invited)

作　　者：赵卫岗 呼新荣 葛锦蔓 刁文婷 冯野[3] ZHAO Weigang;HU Xinrong;GE Jinman;DIAO Wenting;FENG Ye(National Key Laboratory of Science and Technology on Space Microwave,China Academy of Space Technology,Xi′an 710100,China;China Academy of Space Technology,Xi′an 710100,China;Xi′an Institute of Optics and Precision Mechanics,Xi′an 710119,China)

机构地区：[1]西安空间无线电技术研究所空间微波通信全国重点实验室,西安710100 [2]西安空间无线电技术研究所,西安710100 [3]中国科学院西安光学精密机械研究所,西安710119

出　　处：《光子学报》2025年第2期39-49,共11页Acta Photonica Sinica

基　　金：国家重点研究发展计划(No.2022YFC2203804);重点实验室基金(No.2023-JCJQ-LB-007);陕西省重点项目(No.2023KXJ-267);国家自然科学基金(No.62071376)。

摘　　要：系统对比分析现有光束指向控制技术,提出了一种基于铌酸锂晶体的高精度电光光束指向控制方法。采用光轴对称结构,有效降低了电光晶体系统的有效热光系数,显著提升了器件的环境适应性能。数值计算和物理仿真证明了光束偏转的可行性。器件完成封装后,利用Zygo干涉仪测得器件中心通光区域的透射波像差RMS为0.2λ(λ=632.8 nm),红外电荷耦合器件图像传感器角度测量法,测得系统在15 kV电压下的最大光束偏转角度为1.88 mrad。实验结果证明了该器件设计的有效性和可行性,为基于铌酸锂晶体的高精度光束偏转器件的研发奠定了基础,同时为星间激光干涉系统的半物理地面验证实验提供了关键技术储备。Space gravitational wave detection is a groundbreaking effort to observe spacetime ripples caused by cosmic events.It requires deploying laser interferometry systems with inter-satellite baselines ranging from hundreds of thousands to millions of kilometers.These systems need detect picometer-scale displacements induced by gravitational waves.However,this task faces significant technical challenges.Key challenges include ultra-long interferometric baselines(~1 million kilometers),small telescope apertures(~100 mm),and beam degradation due to space environmental factors such as thermal fluctuations,radiation,and residual gas interactions.These effects lead to substantial laser power attenuation(down to~100 picowatts at the receiver)and distortions in beam parameters,including wavefront,polarization,and pointing stability.Achieving sub-nanoradian precision in beam pointing control is critical to maintaining phase stability and ensuring a sufficient signal-to-noise ratio.To address these issues,this study introduces an innovative electro-optic beam-pointing control system using lithium niobate(LiNbO_(3))crystals.This system is designed for high precision,environmental robustness,and scalability.We analyzed various beam-steering technologies,including non-mechanical methods(e.g.,electro-optic,acousto-optic,and liquid crystal)and mechanical methods(e.g.,fast steering mirrors and rotating prisms).Our analysis highlighted the limitations of current technologies,particularly in terms of precision,adaptability to space environments,and wavefront preservation.The proposed system leverages the superior electro-optic properties of LiNbO_(3)crystals.These crystals have a high electro-optic coefficient(r_(33)=30.9 pm/V at 632.8 nm,r_(33)=29.49 pm/V at 1064 nm)and excellent optical transparency in the near-infrared range,making them ideal for high-precision beam steering.The core innovation is in the system's symmetric optical design.It actively compensates for effective thermo-optic effects,a critical bottleneck in conventiona

关 键 词：空间引力波探测 激光干涉测量 光束指向控制 电光晶体 半物理地面验证 

分 类 号：O734[理学—晶体学]