空间引力波探测器中的锁臂控制器设计  

The Arm Locking Controller Design for Space-based Gravitational Wave Observatories

作　　者：张祎 李明哲 王童 沈玉霖 杨杰 辛明 ZHANG Yi;LI Mingzhe;WANG Tong;SHEN Yulin;YANG Jie;XIN Ming(School of Electrical and Information Engineering,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学电气自动化与信息工程学院,天津300072

出　　处：《光子学报》2025年第2期71-84,共14页Acta Photonica Sinica

基　　金：国家重点研究发展计划(No.2021YFC2201902);国家自然科学基金(No.61975149)。

摘　　要：由于引力波信号非常微弱,需要对引力波探测器中激光系统的频率噪声及强度噪声等进行抑制才能满足引力波探测要求,激光锁臂则是抑制激光频率噪声的关键技术之一。将逆向设计思想引入到激光锁臂控制器的优化设计中,具体采用分层式结构,利用多参数协同优化方式,对科学频段内(0.1 mHz~1 Hz)不同频率处的激光频率噪声抑制比进行协同优化。理论建模分析结果表明:优化后的控制器不仅可以提升激光频率噪声抑制效果,还能大幅度提高引力波信号相对于激光频率噪声及其他技术噪声的信噪比。相关研究成果可推广应用到其他架构的噪声耦合锁臂控制器的优化设计中。When an object with mass accelerates,it produces Gravitational Waves(GWs)that are not easily absorbed or scattered.GW is the only means to study some extreme astronomical phenomena.To overcome the limitations from seismic gravity-gradient noise in ground-based GW observatories,several spaced-based GW observatory projects:LISA,DECIGO,Taiji,and TianQin,have been initiated world widely in the past two decades,aiming to detect GWs in the frequency range from 0.1 mHz to 1 Hz(science band).Spaced-based GW observatory is essentially a laser interferometer consisting of three spacecrafts.Because GW is extremely weak,the frequency noise of the lasers inside the interferometer needs to be suppressed by at least 8 to 10 orders of magnitude to meet the detection requirements.To achieve this goal,three techniques are typically employed.The laser's frequency is first prestabilized to a fixed-length ultrastable optical cavity using Pound-Drever-Hall(PDH)locking method;then the arm length of the constellation,which is much more stable than the laser's frequency in the science band,is used as a reference to further reduce the laser's phase noise,and this is called arm locking technique;finally,the residual laser frequency noise can be canceled by Time Delay Interferometry(TDI),with the help of virtual delays introduced in data postprocessing.Despite significant advances in arm locking techniques over the past two decades,all arm locking controllers reported so far have been based on the traditional forward design approach:first giving the concrete form of the controller and then fine-tuning a small number of parameters.This method has a very limited degree of freedom for optimization,which severely limits the noise suppression performance of the arm locking system.In this paper,for the first time,the inverse design idea is employed for the design of the arm locking controller.A layer structure is used for the controller optimization.The data input layer is responsible for modeling noise,gravitational wave signal and controller pa

关 键 词：引力波探测 锁臂 激光频率噪声抑制 逆向设计 反馈控制 

分 类 号：O412.1[理学—理论物理] TN249[理学—物理]