空间引力波探测是目前国内外热门的研究领域，拟在空间中进行0.1mHz~1Hz频段的引力波探测，以期2030年左右联合地面探测开启引力波天文学时代。已经提出的空间引力波探测计划，包括欧美的LISA计划、我国的太极计划和天琴计划。技术要求在百万公里量级臂长上，0.1mHz~1Hz频段内位移波动测量精度达到1 pm/Hz^1/2 。作为目前最为成熟的技术手段，激光差分干涉被广泛接受并应用于空间引力波探测任务。为验证包括激光差分干涉在内的关键技术，已发射的技术验证卫星包括LISA计划的LISA Pathfinder、GRACE Follow-On及我国的太极一号、天琴一号等。LISA Pathfinder测量精度达到了敏感频段内的噪声极限，最高可达32.0fm/Hz^1/2 ，噪声物理模型认识清晰。国内由于起步较晚，在适合各干涉系统的噪声模型建立、验证及差异化噪声消减方案方面与LISA有着巨大的差距。

本文针对太极计划干涉仪噪声的模型建立、实验验证和噪声消减问题，围绕干涉仪测试，特别是地面测试环境时，遇到的典型噪声源进行分类讨论，给出可行的抑制方法和方案。主要解决的关键科学技术问题如下：1）太极计划干涉系统的噪声指标体系与针对性的噪声抑制方案？2）针对干涉仪平台光程噪声，如何有效建立光程噪声与相关参量间的模型？3）现阶段太极计划初代超稳光粘干涉仪平台噪声评估，能否能通过建立有效的噪声消减方法，进一步提高干涉仪的测量精度？根据所面临的关键问题，本文主要完成以下工作：

建立初步的太极计划干涉仪噪声指标体系，给出完整的噪声分类、指标架构及出处。太极计划干涉仪系统硬件上由激光器、干涉仪光学平台、望远镜、探测器和相位计组成。为实现pm级星间激光测距指标，从顶层指标步步分解，对组成部分各单机载荷进行逐步剖析。首先介绍了干涉仪系统的功能及组成，并对各分系统级指标进行噪声分解；其次从子系统层面逐步分解干涉系统的各类噪声，对个子系统的各项噪声指标进行初步的约束。最终，初步建立太极计划干涉仪系统的噪声指标体系，为后续的噪声讨论奠定理论基础。

针对干涉仪光程噪声的力扰动问题，通过太极一号干涉仪，给出扰动力与光程噪声间传递函数的建立方法。由于干涉仪在空间中会受到太阳风、太阳光压、微推进器对卫星的作用力、星上微振动、元件内应力及卫星结构热变形等噪声的影响，产生光程噪声。为了分析微推进器对干涉测量的影响，本文提出了一种建立力扰动噪声模型的方法，即通过“力扰动仿真-光学追迹-频谱分析”建立力噪声与光程噪声间的传递函数。以太极一号干涉仪为例，通过仿真和实验验证了此方法建立传递函数的有效性。

与力扰动噪声分析方法类似，针对影响干涉仪光程噪声的热漂移问题，通过太极一号鉴定件，给出热漂移与光程噪声间传递函数的建立方法。卫星在轨期间，太阳常数或者载荷功率的波动等因素会使干涉仪的温度场发生波动，进而影响mHz频段的干涉仪测量精度。为研究热漂移和光程噪声间的耦合关系进而抑制热漂移噪声，提出通过“热扰动仿真-光学追迹-频谱分析”的方法，建立二者的耦合关系。以太极一号干涉仪为例，通过仿真和实验验证了这种方法建立传递函数的有效性。

针对干涉系统、卫星结构等力热引起的变形测量需求，本文结合差分干涉技术及光纤传感技术用于力、微变形测量。基于太极计划干涉仪的共模噪声抑制方法，设计并搭建对结构变形敏感的接触式全光纤微变形监测传感器。通过微变形的监测反映扰动量引起的应力场分布情况，为光程噪声中力扰动噪声的抑制提供基础。实验结果表明该传感器的光程噪声与变形量之间的耦合关系与理论预测基本一致，并体现出良好的噪声抑制效果。

针对目前太极计划初代光粘超稳干涉仪的噪声标定问题，在地面进行全面测试，给出各类噪声的分析，建立噪声模型，并针对不同噪声建立差异化抑制方案。首先介绍光粘超稳干涉仪光路、实验系统搭建及初步测试性能；其次，对各类噪声进行分析及建模，如光程差异噪声、激光强度噪声、激光频率噪声、温度漂移噪声、角度耦合噪声等，并对不同的噪声建立差异化抑制方案；最终通过“扰动量测量-相关性分析-数据后抑制”的方法，针对不同噪声的频谱特性，在特定的频段内，对光程噪声进行数据后处理抑制。抑制后表明，太极计划初代光粘超稳干涉仪测量精度在1Hz处为1.1pm/Hz^1/2 ，0.1Hz为5pm/Hz^1/2 ，0.01Hz处为8pm/Hz^1/2 ，1mHz处为150pm/Hz^1/2 .

Space-based gravitational wave detection, currently a hot research field at home and abroad, is planned to detect the gravitational wave in 0.1mHz~1Hz, which would open the era of gravitational wave astronomy with ground-based detection around 2030. The typical space-based detection missions include LISA program from ESA and NASA, Taiji program and TianQin program from China. As a mature technology, laser heterodyne interference has been accepted and utilized in space-based gravitational wave detection widely. The measurement precision of 1pm/Hz^1/2  is required when the inter-satellite distance is in the order of millions of kilometers. The technology validation satellites were launched to verify the key technologies in the system, such as LISA Pathfinder, GRACE Follow-On, Taiji-1 and TianQin-1. The measurement precision of LISA Pathfinder has reached 32.0fm/Hz^1/2, which is the noise limit within the frequency range of interest, and the noise model has been analyzed and established. Become of the late start, the domestic research is still in the development stage especially on the noise model establishment, experimental verification and noise suppression when compared to LISA.

To realize the noise model establishment, experimental verification and noise suppression in Taiji interferometer, the noise sources are described, and the noise suppression method is investigated. The main scientific and technical problems to be solved in this article are as follows: 1) Which noises are included in the interference system and how to suppress the effect of these noises? 2) How to establish the transfer function between the noise disturbance and the optical path noise in the interference optical bench? 3) How to evaluate the measurement noise of the Taiji initial ultrastable optical interferometer with Hydroxide-catalysis bonding, and how to increase the measurement precision by the effective noise suppression method? Based on the above challenges, the article is constituted as follows:

Establishing the noise system of interferometer in Taiji, including the noise classification, architecture and noise sources. The interference system consists of laser, optical bench, telescope, photodetector and phasemeter. To realize the measurement target, the noise is decomposed from the top level and analyzed through each subsystem. Firstly, the function and constitution of interferometer system is introduced, and the noise of each subsystem is decomposed; Afterwards, the possible noise sources in each subsystem is introduced and the related noise requirement is given; Finally, the noise system of interferometer is established.

To suppress the effect of force disturbance to optical path noise in interferometer, the transfer function can be established between force and optical path noise in Taiji-1 interferometer. The optical path noise can be influenced by external disturbance, such as the solar wind, solar pressure, force disturbance from micro thruster, micro vibration, internal stress and thermal-induced deformation. To analyze the influence of the micro thrust to interference measurement, the transfer function between force disturbance and optical path noise is established by “simulation of force disturbance-optical path tracing-frequency spectrum analysis”, proposed in this article. The effectivity of this method is verified by the simulation and experiment procedure of Taiji-1 interferometer.

The thermal-induced optical path noise can be suppressed by the transfer function between temperature fluctuation and optical path noise in Taiji-1 interferometer. During the orbit of satellite, the temperature can be influenced by the fluctuation of solar constant and electrical element power. It leads to the interference measurement noise at mHz frequency range. To suppress the thermal-induced optical path noise, the transfer function between the temperature fluctuation and optical path noise is established by the method, which is “simulation of temperature fluctuation-optical path tracing-frequency spectrum analysis”. The effectivity of this method is verified by the simulation and experiment procedure of Taiji-1 interferometer similarly.

For the measurement requirement of deformation caused by the interference optical bench and satellite structure, the heterodyne interference fiber optic sensing system is proposed. Based on the common mode noise suppression method used in Taiji interferometer, a contact all-fiber-optic micro-deformation monitoring sensor sensitive to the deformation is designed and constructed. Through the deformation monitoring, the stress field can be obtained and used to provide a foundation for the suppression of force disturbance. The experimental results reveal that the sensing scheme aligns with the theoretical predictions with the acceptable tolerance for error and the deformation measurement error of the sensor is reduced through the noise suppression scheme.

To evaluate the measurement noise of the Taiji initial ultrastable optical interferometer with Hydroxide-catalysis bonding, the ground experiment is arranged, where the noise model and different suppression schemes for each noise are established and investigated. Firstly, the composition and performance of interferometer is introduced and tested preliminarily. Then, various types of noise are analyzed and modeled, such as optical path difference noise, laser intensity noise, laser frequency noise, temperature fluctuation noise and angular coupling noise. Besides, the different noise suppression scheme with respect to each noise model is introduced. Finally, according to the different frequency range, the optical path noise caused by these noises can be suppressed by the frequency spectrum method, which is “disturbance measurement-correlation analysis-data postprocessing”. The noise suppression result shows that the measurement precision of the interferometer is 1.1pm/Hz^1/2 at 1Hz, 5pm/Hz^1/2  at 0.1Hz, 8pm/Hz^1/2 at 0.01Hz and 150pm/Hz^1/2 at 1mHz, respectively.