宋奇林 1,2,3,4李杨 1,3,4周子夜 1,3,4肖亚维 1,2,3,4[ ... ]饶长辉 1,2,3,4
1 自适应光学全国重点实验室,四川 成都 610209
2 中国科学院大学,北京 100049
3 中国科学院光电技术研究所,四川 成都 610209
4 中国科学院自适应光学重点实验室,四川 成都 610209
Overview: Since the groundbreaking discovery of gravitational waves, the scientific community has fervently pursued the exploration of low-frequency gravitational waves to glean deeper insights into the cosmos. The inherent limitations of ground-based conditions, however, pose formidable challenges for detectors in capturing gravitational waves below the 1 Hz threshold. Consequently, the imperative has shifted toward the deployment of space-based gravitational wave detectors as the paramount solution for effective low-frequency gravitational wave detection. At the crux of space-based gravitational wave detection lies the pivotal role of spaceborne telescopes. Given the expansive transmission distances spanning magnitudes of 109 m between celestial constellations, the demand for nanoradian-level precision in telescope pointing accuracy becomes non-negotiable. The concomitant necessity for high-precision measurements and calibration emerges as a prerequisite for achieving the exacting standards of pointing accuracy in spaceborne telescopes dedicated to gravitational wave detection. To ameliorate the deleterious effects of pointing deviations on gravitational wave detection, this study strategically optimizes key parameters, including microlens structures, detector selection, and algorithmic frameworks, thereby achieving a breakthrough in high-precision pointing deviation measurements. Leveraging a low-density microlens array with extended sub-aperture focal lengths enhances the spatial scale of the light spot within each sub-aperture. This, coupled with detectors boasting a high signal-to-noise ratio, synergistically elevates the pointing detection accuracy of each discrete lens. Moreover, the paper introduces an innovative, Hartmann principle-based methodology for high-precision pointing deviation measurements, deploying a spatially reused paradigm across multiple sub-apertures. By aggregating measurement results from diverse sub-apertures, the approach effectively mitigates the influence of assorted random errors on measurement accuracy, thereby markedly enhancing the precision of pointing deviation measurements. Illustrating the efficacy of these methodologies, the paper exemplifies their application within the ambit of the "Tianqin Plan" for space-based gravitational wave detection. Employing numerical simulations and factoring in the design parameters of the Hartmann sensor, the study performs a meticulous analysis of pointing deviation measurement accuracy. Comparative analysis between single sub-aperture and sub-aperture correlation reuse technologies reveals a compelling enhancement in measurement accuracy, approximating a sevenfold improvement with the latter. The pointing deviation measurement accuracy achieved through sub-aperture correlation reuse technology is quantified at approximately 18.81 nanoradians. Considering the optical magnification inherent in spaceborne telescopes, estimated at around 30 times, the resultant pointing deviation measurement accuracy reaches an impressive 0.62 nanoradians. This design precision significantly surpasses the stipulated 1 nanoradian accuracy requirement for ground-based gravitational wave pointing deviation measurements. As a prudential measure, the proposed design incorporates a substantial margin to accommodate potential accuracy diminution attributable to external perturbations during empirical testing.
星载望远镜 指向偏差测量 哈特曼 多子孔径空间复用 spaceborne telescope pointing deviation measurement Hartmann multi-subaperture spatial multiplexing
1 中国科学院自适应光学重点实验室, 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
针对便携式快反镜系统对小尺寸快反镜的需求,设计了一种紧凑型压电式驱动的快反镜结构。通过对快反镜的驱动元件、位移放大机构、解耦支撑的合理布局,具有75 mm通光口径的快反镜机械结构的外形尺寸为90 mm×90 mm×33 mm。最后对快反镜进行了实验检测,结果显示紧凑型快反镜的角行程为4.2 mrad,机械谐振频率为671 Hz,表明该快反镜系统性能好,可满足小尺寸快反镜光学系统的应用需求。
光学器件 快反镜 紧凑型 谐振频率 自适应光学 中国激光
2021, 48(13): 1305002
1 中国科学院 自适应光学重点实验室,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
针对拼接主镜,开展子镜面共相校正装置的结构设计与性能测试。该装置整体采用粗调精调结合的两级式结构,主要由粗调级、精调级和横向卸载机构等部分构成。文章在基于有限元方法的装置整体设计与性能分析基础上,完成装置样件研制与基本性能测试。实测结果表明:该装置可平移±2.5 mm,校正精度约30 nm RMS(root mean square),带模拟镜面后固有频率约70.3 Hz,与设计结果相符,满足主镜系统技术指标需求。