Overview: Gravitational waves are spacetime oscillations radiated outward by accelerating mass objects. Significant astronomical events in the universe, such as the merging of massive black holes, emit stronger gravitational waves. Detecting gravitational waves allows for a deeper study of the laws governing celestial bodies and the origins of the universe, making accurate detection crucial. Gravitational wave detection technology utilizes Michelson interferometers to convert the extremely faint spacetime fluctuations caused by gravitational waves into measurable changes in optical path length. Recently, ground-based large Michelson interferometers have achieved direct detection of high-frequency gravitational waves. However, the detection of low-frequency gravitational waves, which is equally important, is not feasible on the ground due to arm length and ground noise issues. This necessitates the construction of ultra-large Michelson interferometers in space for low-frequency gravitational wave detection. Spaceborne gravitational wave detection telescopes play a vital role in collimating bidirectional beams in ultra-long interferometric optical paths in space. The extremely subtle changes in optical path caused by gravitational waves impose high demands for pm-level optical path length stability and below 10^?10 level backscattered light in these telescopes. The ultra-high level index requirements exceed the precision limits of current ground testing techniques for telescopes. To ensure that spaceborne telescopes maintain their ultra-high design performance in the orbital environment, developing testing and evaluation techniques for these key indicators is a crucial prerequisite for the success of the space gravitational wave detection program. This paper provides an overview of the development of spaceborne gravitational wave detection telescopes, both domestically and internationally. It focuses on the current status and some test results of optical path length stability and backscattered light testing of telescopes under development, as well as further testing plans, providing a reference for the testing and evaluation of Chinese space gravitational wave detection space-borne telescopes.

采用功率谱反演法模拟了同轴叠加产生的双拉盖尔-高斯涡旋光束（Double Laguerre-Gaussian Vortex Beam，DLGVB）在海洋湍流中传输时的光强和相位分布，仿真分析了DLGVB光束在不同海洋湍流参数下的闪烁指数以及在基于开关键控调制的水下光通信系统中的通信误码率。结果表明，随着湍流动能耗散率的减小，盐度温度波动平衡参数、温度方差耗散率及传输距离的增加，闪烁指数逐渐增加；随着湍流动能耗散率以及拓扑电荷差值的增加，误码率减小。在海洋湍流环境下，使用DLGVB光束进行传输可以抑制海洋湍流带来的干扰，选择最佳的拓扑电荷差值，可以有效提高传输通信质量及通信系统容量。本文研究结果对涡旋光束及其叠加态在海洋湍流下传输特性研究及水下光通信系统持续扩容的发展需求方面具有重要的参考价值。