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.

Overview: Space gravitational wave detection missions typically consist of three identical satellites, with two laser links between the satellites at an angle of sixty degrees forming a Michelson interferometer. The arm length changes are measured using high-precision inter-satellite laser interferometry. As a key component of the inter-satellite laser interferometry system, the telescope system needs to have picometer-level optical path stability, a wavefront error of λ/30, and stray light less than 10^?10 of the transmitted power. To meet the requirements of space gravitational wave detection for the telescope system, an optical and mechanical integrated analysis and optimization method is proposed to design and optimize the primary mirror and its supporting structure. The off-axis parabolic primary mirror adopts the side three-point support method, and the influence of the support point position on the mirror surface shape and the rigid body displacement under gravity conditions has been studied. Optimization of the size of the triangular lightweighting holes on the primary mirror has been performed, and density-based topology optimization has been used to optimize the support backplate while ensuring that the first-order mode of the primary mirror component remains essentially unchanged. The flexural matrix of the primary mirror component supported by a parallel bipod linkage structure was derived based on spinor theory, and an evaluation function for the support structure was established. The size parameter range of flexible support was preliminarily determined by Matlab analysis. A optical-mechanical integrated simulation platform is set up to optimize the parameters of the support structure using a weighted sum method to convert the multi-objective optimization problem into a single-objective optimization problem. The results showed that the first-order frequency of the primary mirror component system was 392.43 Hz. Under gravity and temperature loads, the deformation of the primary mirror surface was better than λ/60, the translational rigid body displacement was better than 2.5 μm, and the rotational rigid body displacement was better than 0.5 μrad, all of which met the design specifications. Under space thermal disturbance of 10 μK/Hz^1/2, the size stability of the primary mirror component, represented by the displacement of the central point of the mirror, was at a level of 10 pm/Hz^1/2.

大功率白光LED封装主要分为玻璃荧光片封装和荧光粉胶封装。本文提出一种用荧光胶封装大功率白光LED的方法，优化白光LED的发光面的均匀性，并分析了荧光胶封装和用荧光片封装的大功率白光LED的光热性能。实验结果表明，在1 400 mA电流驱动下，荧光胶封装白光LED的光通量为576.07 lm，比荧光片封装白光LED的光通量高15.5%，光转换效率为35.8%。在温度从25 ℃提升到125 ℃的过程中，荧光胶封装器件的亮度衰减了20%，色温从5 882.11 K提高到6 024.22 K。荧光胶封装的白光LED在常温下的热阻为1.7 K/W，与玻璃荧光片封装的热阻接近。在840 h高温高湿老化和1 600 h高温老化实验中，荧光胶封装的相对光衰均能稳定在97%。

近年来，近红外荧光粉转换发光二极管（NIR pc-LED）在夜视、生物成像和无损检测等领域引起了广泛关注。然而，获得兼具高量子效率和优异热稳定性的近红外荧光粉仍然是一个巨大挑战。本文利用高温固相法合成了一种新型近红外荧光粉BaY₂Al₂Ga₂SiO₁₂∶Cr³⁺（BYAGSO∶Cr³⁺），并系统研究了材料的结构和发光性质。在440 nm蓝光激发下，BYAGSO∶Cr³⁺荧光粉的发射光谱在650~850 nm范围内呈现锐线和宽带的混合发射，源于Cr³⁺：²E→⁴A₂自旋禁戒跃迁和⁴T₂→⁴A₂自旋允许跃迁发射。该近红外发光表现出可观的量子效率和良好的热稳定性，最优化样品的外量子效率可达30.3%，在200 ℃时样品的发光强度可保持其在室温时强度的99%。通过将BYAGSO∶Cr³⁺荧光粉与450 nm蓝光LED芯片结合，我们封装了一个NIR pc-LED器件。该器件在300 mA驱动电流下，输出功率为70.83 mW；在20 mA驱动电流下，光电转换效率为11.20%。研究结果表明，BYAGSO∶Cr³⁺在NIR pc-LED领域具有良好的应用前景。

为了开发出高效稳定的单一基质白光发射荧光材料，本工作通过高温固相法成功合成了一系列La₄GeO₈∶Bi³⁺，Eu³⁺荧光粉样品，并通过X射线衍射、室温光谱、变温光谱等手段研究了实验样品的结构与发光性能。研究发现，Bi³⁺离子在该结构中占据两种不同的格位（Bi³⁺（Ⅰ）和Bi³⁺（Ⅱ）），且在紫外光激发下呈现两个峰值分别在475 nm和620 nm的宽带发射。对于Bi³⁺、Eu³⁺共掺样品，由于Bi³⁺（Ⅰ）与Eu³⁺之间的竞争吸收、Bi³⁺（Ⅰ）至Bi³⁺（Ⅱ）以及Bi³⁺（Ⅱ）至Eu³⁺的能量传递作用，可实现蓝色至红色、橙红色至红色的可调发光。特别地，样品La₄GeO₈∶0.07Bi³⁺，0.06Eu³⁺在313 nm光激发下可获得CIE值为（0.335，0.319）的优异白色发光。此外，该白光发射材料具有较佳的发光热稳定性，当温度升高至380 K时，发光积分强度仍然为室温的59%，表明其在白光二极管上具有潜在的应用价值。

研究了粉末原子层沉积技术（ALD）在白光LED用K₂SiF₆∶Mn⁴⁺（KSFM）红色荧光粉包覆和表面改性中的应用，以及对其结构特性、发光性能和湿热环境中稳定性的影响。结果表明，采用ALD技术以三甲基铝作为前驱体、臭氧作为氧化剂，可以在KSFM表面形成氧化铝包覆层。X射线衍射、表面形貌分析表明，ALD处理过程不会影响KSFM荧光粉的晶相和形貌特征。发光光谱分析表明，由于氧化铝钝化特性还会增强KSFM荧光粉的发光强度，并且不改变其发光波长。相较于未经包覆的KSFM荧光粉，包覆层可以显著改善KSFM粉末的湿热环境稳定性，ALD包覆后样品的相对发光强度在85%湿度/85 ℃环境中老化处理24 h后仍能保持初始值的84%。

从提出自由基的双线态电致发光新机制，到成功实现高发光效率的自由基，再到开发具有可调控自旋态的发光双自由基，这一系列的创新为一个世纪前已存在的自由基领域重新注入了新的活力。本文追溯了稳定有机自由基的历史，并介绍了我们在发光自由基领域近期的研究进展。

目标的变化和任务的拓展对光电跟瞄系统提出了快速机动的要求，从地基平台到车载、船载、机载、星载等运动平台是光电跟瞄系统的重要发展趋势。基于惯性参考单元（Inertial Reference Unit，IRU）的视轴稳定方式是克服运动平台高频扰动，实现光电跟瞄系统微弧度甚至亚微弧度级跟瞄的主要技术手段。针对运动平台光电跟瞄系统精确指向对载体基座扰动抑制的需求，分析和对比了IRU的各种技术方案，特别介绍了利用低噪声、宽频带惯性传感器敏感角扰动，并通过反馈控制实现视轴惯性稳定的系统方案。从此类IRU系统的工作原理出发，阐述了系统的两种工作模式及功能特点，建立了系统数学模型。然后，介绍了IRU的国内外研究进展及发展方向，指出惯性传感、支承结构和控制系统是决定IRU稳定能力的关键因素，梳理了三项关键技术的研究动态。最后，总结了IRU的空间应用情况，并结合目前的应用需求对其未来应用领域进行了探讨。