空间引力波探测任务中, 由于干涉臂臂长的巨大差异, 激光频率不稳定噪声成为系统最大的噪声源之一。需采用Pound-Drever-Hall锁腔、锁臂和TDI(Time Delay Interferometer)技术三级联合, 将此噪声压制到10-6 Hz1/2量级, 才能使得频率噪声低于散粒噪声。而实现TDI技术需要准确测量卫星间的绝对距离和星间通信。本文以空间引力波探测中的绝对距离测量和通信技术为背景, 详细阐述此项技术的实现原理和方法。拟通过EOM(Electro-Optic Modulator)将测距伪随机码和通信码调制至主激光相位中, 再传输至远端航天器。在远端航天器通过锁相环和延迟环组成的解调系统计算伪随机码的时间延迟, 进而解析出卫星间的绝对距离和通信信息。相关结论可为未来的验证实验奠定理论和技术基础, 同时为我国未来空间引力波探测的相关技术发展提供一定参考。

Due to the large unequal interferometer arm, laser frequency jitter noise is the dominant noise in space gravitational wave detection. This noise can be less than shot noise when the frequency jitter is suppressed below than 10-6 Hz1/2 through the combination of PDH(Pound-Drever-Hall), arm locking and TDI (Time Delay Interferometer) technologies. However, absolute ranging and laser communication are the preconditions of the TDI. In this paper, we discuss the principle and implementation of the absolute ranging and laser communication. The pseudo-random code and communication code are modulated by the EOM(Electro-Optic Modulator) into the phase of the main laser beam and then sent to the far satellite. The absolute distance and the message can be obtained through the PLL(Phase Lock Loop) and the DLL(Delay Lock Loop). The related conclusions can be regarded as the basis and principle for related experimentation and will give a design reference for future space gravitational wave detection in our country.