1 自适应光学全国重点实验室,四川 成都 610209
2 中国科学院光电技术研究所,四川 成都 610209
3 中国科学院大学,北京 100049
4 山东高等技术研究院,山东 济南 250100
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.
空间引力波探测 星载望远镜 地面测试 光程稳定性 后向杂散光 space gravitational wave detection spaceborne telescope ground test optical path length stability backscattered light
“天琴计划”教育部重点实验室,天琴中心 & 物理与天文学院,天琴前沿科学中心,国家航天局引力波研究中心,中山大学(珠海校区),广东 珠海 519082
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/Hz1/2, 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/Hz1/2.
引力波望远镜 Bipod连杆支撑 面形变化 尺寸稳定性 gravitational wave telescope bipod linkage support surface deformation dimensional stability
1 同济大学物理科学与工程学院精密光学工程技术研究所,上海 200092
2 上海大学理学院,上海 200444
3 中国科学技术大学国家同步辐射实验室,安徽 合肥 230029
Mo/Si多层膜是13.5 nm极紫外波段理想的反射镜膜系,它与极紫外光源的结合使得极紫外光刻成为了目前最先进的制造手段之一。极紫外光源的实际应用对Mo/Si多层膜提出了高反射率、高热稳定性、抗辐照损伤、大口径等诸多要求。针对极紫外光源用Mo/Si多层膜面临的膜厚梯度控制和高温环境问题,利用掩模板辅助法对大口径曲面基底上不同位置处的多层膜膜厚进行修正;选择C作为扩散阻隔层材料,对磁控溅射法制备的Mo/Si、Mo/Si/C和Mo/C/Si/C三种多层膜在300 ℃高温应用环境下的热稳定性展开了研究。研究结果表明:通过掩模板辅助的方式能够将300 mm口径曲面基底上不同位置处的Mo/Si多层膜膜厚控制在预期厚度的±0.45%以内,基底上不同位置处Mo/Si多层膜的膜层结构和表面粗糙度基本相同;引入C扩散阻隔层后,经过300 ℃退火,Mo/Si多层膜的反射率损失从9.0%减少为1.8%,说明C的引入能够有效减少高温对多层膜微结构的破坏和对光学性能的影响,提高了多层膜的热稳定性。
激光光学 极紫外光源 Mo/Si多层膜 磁控溅射 膜厚控制 热稳定性
1 广东晶科电子股份有限公司, 广东 广州 511458
2 华南理工大学物理与光电学院 广东省光电工程技术研究开发中心, 广东 广州 510640
3 华南理工大学 微电子学院, 广东 广州 510640
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%。
大功率白光LED 玻璃荧光片 荧光粉胶 光热性能 热稳定性 high power WLEDs PiG PiS photothermal performance thermal performance
1 中国科学院长春应用化学研究所 稀土资源利用国家重点实验室, 吉林 长春 130022
2 中国科学技术大学 应用化学与工程学院, 安徽 合肥 230026
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。
近红外发射 Cr3+ 热稳定性 量子效率 荧光粉转换发光二极管 near-infrared emission Cr3+ thermal stability quantum efficiency NIR pc-LED
辐射研究与辐射工艺学报
2024, 42(1): 010203