1 中国科学院国家天文台南京天文光学技术研究所, 江苏 南京 210042
2 中国科学院天文光学技术重点实验室, 江苏 南京 210042
3 中国科学院大学, 北京 100049
4 加利福尼亚州立大学北岭分校物理与天文学院, 加利福尼亚州 91330
目前太阳活动观测存在视场小和分辨率低的问题。单共轭自适应光学系统可校正的视场范围较小, 多层共轭自适应光学系统使用三维重构的方法, 耗时长且过程繁琐; 而太阳地表层自适应光学系统只校正地表层湍流, 效率高, 能快速获得大视场、高分辨率图像。利用YAO软件, 在四导星阵列分布情况下, 应用平均算法对太阳, 地表层自适应光学系统在40″和60″优化视场、J和H波段的性能进行数值仿真, 并与相同条件下仿真得到的单共轭自适应光学系统性能结果进行比较。结果表明, 在60″~120″成像视场内, 地表层自适应光学系统的斯特列尔比值比单共轭自适应光学系统提高了130%~210%, 该结果与太阳自适应光学领域其他软件得到的仿真结果一致。
大气光学 主动或自适应光学 波前传感 大气湍流 地表层自适应光学 YAO软件 激光与光电子学进展
2017, 54(9): 090101
1 济源职业技术学院, 河南 济源 459000
2 中国科学院 长春光学精密机械与物理研究所, 吉林, 长春 130033
3 中国科学院 研究生院, 北京 100049
为了定量研究相位差波前探测技术(phase diversity technique, PD)对波前探测和图像重建的精度, 本文分别进行了数值模拟以及相关实验。数值模拟中采用了均方根(root-mean-square, RMS)分别为0.1λ~0.5λ的五组随机畸变波前, 获得其退化的焦面图像和相应的离焦图像信息, 利用PD技术对其进行波前探测和图像重建, 波前探测的残余误差RMS值均达到了10－5λ水平, 重建图像在分辨率和对比度上有明显提升。搭建了基于液晶空间光调制器的实验系统, 利用液晶空间光调制器来定量施加随机的波前像差, 可以有效解决湍流屏数据难以量化的问题。同样将PD技术应用于本实验所采集到的退化焦面图像和相应离焦图像, 对于RMS值为0.306λ的随机波前像差, 探测波前的残余误差为0091λ, 图像重建结果与模拟结果高度一致, 本文列举并分析了可能造成实验误差的多种因素, 同时为该技术应用于液晶系统积累了技术基础。
相位差探测技术 波前探测 图像重建 phase diversity technique wave-front sensing image reconstruction
1 中国科学院西安光学精密机械研究所, 西安 710119
2 西安电子科技大学 计算机学院, 西安 710071
在位相差异技术原理的基础上, 利用现有平台, 通过室内实验以及室外推扫成像试验, 检验了位相差异技术波前反演的效果.试验表明: 以干涉仪实测波前与反演波前的残差均方根误差作为评价标准, 基于位相差异技术的波前反演精度可达1/40λ(λ=632.8 nm); 同时, 利用反演波前进行的图像复原滤波能够大幅改善推扫退化图像的品质, 复原后图像信噪比的提升量优于40%, 奈奎斯特频率处调制传递函数的提升量超过80%.间接地证明了位相差异波前反演技术的实际效能, 为位相差异波前反演技术的空间应用奠定了基础.
空间光学相机 波前反演 位相差异 图像复原滤波 Space-borne camera Wave-front sensing Phase diversity Image restoration
Author Affiliations
Abstract
1 Key Laboratory on Adaptive Optics, Chinese Academy of Sciences, Chengdu 610209, China
2 Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu 610209, China
Our adaptive optics system based on a non-modulation pyramid wavefront sensor is integrated into a 1.8 m astronomical telescope installed at the Yunnan Observatory in LiJiang, and the first light with high-resolution imaging of an astronomical star is successfully achieved. In this Letter, the structure and performance of this system are introduced briefly, and then the observation results of star imaging are reported to show that the angular resolution of an adaptive optics system using a non-modulation pyramid wavefront sensor can approach the diffraction limit quality of a 1.8 m telescope.
010.1080 Active or adoptive optics 010.7350 Wave-front sensing Chinese Optics Letters
2016, 14(10): 100101
Author Affiliations
Abstract
College of Information Science & Electronic Engineering, Zhejiang University, Hangzhou 310027, China
Electromagnetic vortices, which describe the orbital angular momentum (OAM) carrying waves with a helical phase front, have recently attracted much interest in a radio frequency domain due to their potential applications in many diverse areas. In an OAM-based scenario, the antenna for OAM mode multiplexing/demultiplexing plays an essential role in controlling the overall system performance. In this paper, we demonstrated theoretically and experimentally an easily realized OAM antenna based on the traveling-wave circular loop structure for efficiently multiplexing/demultiplexing multiple OAM modes; in addition, its general propagation characteristics including the polarization, divergence, and radiation pattern are mathematically analyzed. Schemes for antenna size reduction and various radiation pattern manipulations have also been discussed to realize a more flexible and compact system.
Optical vortices Optical vortices Wave-front sensing Wave-front sensing Electromagnetic optics Electromagnetic optics Microwaves Microwaves Photonics Research
2016, 4(5): 050000B9
建立了采用相关波前探测算法(Correlation wave-front sensing algorithm, COR)的自适应光学(Adaptive Optics, AO)系统的数值模型, 对准直光束大气传输自适应光学校正进行了数值模拟, 分析了不同热晕强度条件下光子噪声和读出噪声对系统校正效果的影响, 并与质心(Center of Gravity, COG)算法和阈值质心(Threshold Center of Gravity, TCOG)算法进行了对比。数值模拟结果表明, COR算法对噪声和热晕强度的变化具有更好的鲁棒性, 可以提高夏克-哈特曼波前探测器(Shack-Hartmann Wave-front Sensor, SH-WFS)在低信噪比(Signal to Noise Ratio, SNR)条件下的波前探测精度, 同时还可以较好地抑制噪声诱发的相位补偿不稳定性(Phase Compensation Instability, PCI), 改善低信噪比条件下大气热晕校正的稳定性。
自适应光学 相关波前探测算法 噪声 热晕效应 位相补偿不稳定性 adaptive optics correlation wave-front sensing algorithm noise thermal blooming effect phase compensation instability 红外与激光工程
2016, 45(10): 1032001
1 中国科学院自适应光学重点实验室，成都 610209
2 电子科技大学光电信息学院，成都 610054
3 中国科学院光电技术研究所，成都 610209
4 中国科学院大学，北京 100049
相位差算法 (PD)不仅应用于波前传感器还可以作为一种图像复原技术，在波前复原与高分辨力图像事后图像复原有很大的潜力；但是，由于相位差算法的计算量大导致了在 PC平台上很难实现实时处理。以 CPU与 GPU之间较少的数据交互为原则，本文首先对 PD计算过程进行了分析，然后在多 GPU平台上，对 PD算法进行任务划分及优化。实验结果表明，在相差 PV=2λ条件下对于 256 pixels×256 pixels大小图像，经过 50次迭代单 GPU和双 GPU分别耗时 53 ms和 45 ms。
相位差算法 自适应光学 波前探测 图像复原 并行计算 phase diversity adaptive optics wave front sensing image restoration parallel computing
Author Affiliations
Abstract
Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
Phase diversity (PD) is a kind of wavefront sensing technology based on image collecting and post-processing. We apply the PD technology to align an off-axis three-mirror reflecting anastigmatic system precisely. It can be concluded that the wavefront error obtained by PD agrees well with the interferometric result. The focused images are also restored according to the testing results of PD, and the qualities of restored images are improved.
100.5070 Phase retrieval 010.7350 Wave-front sensing 100.3020 Image reconstruction-restoration 110.6770 Telescopes Chinese Optics Letters
2015, 13(s1): S11003
中国科学院 长春光学精密机械与物理研究所, 吉林 长春 130033
设计了1.23 m地基望远镜自适应系统的非共光路标定系统。针对自适应光学系统非共光路像差检测中遇到的问题, 构造了离焦量不可测情况下的相位差异法的评价函数。利用多通道约束波前的解集和像差检测与变形镜调整互相迭代最终收敛的办法, 弥补了测量条件不理想对像差检测的影响。与双通道相位差异法相比, 多通道相位差异法对目标光源形状的容忍力更强, 理论上对波前求解精度更高。将该方法应用于1.23 m地基望远镜自适应系统的非共光路静态像差测量中, 取得了良好的效果, 使光路装调更加方便。通过改变变形镜的初始偏置对测得的像差进行校正, 提高了望远镜光学系统的成像质量。
自适应光学 波前探测 非共光路检测 多通道相位差异法 adaptive optics wave-front aberration detection calibration of no-common path aberration multi-channel phase-diversity wave-front sensing 光学 精密工程
2014, 22(12): 3175
Author Affiliations
Abstract
1 Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, China
2 Max-Planck-Institute for Astronomy, K?nigstuhl 17, D-69117 Heidelberg, Germany
3 Graduate School of Chinese Academy of Sciences, Beijing 100039, China
4 LESIA - Observatoire de Paris, 77, Avenue Denfert-Rochereau, 75014 Paris, France
5 Max Planck Institute for Extraterrestrial Physics, Postfach 1312, 85741 Garching, Germany
6 Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, China
The adaptive optics system for the second-generation VLT-interferometer (VLTI) instrument GRAVITY consists of a novel cryogenic near-infrared wavefront sensor to be installed at each of the four unit telescopes of the Very Large Telescope (VLT). Feeding the GRAVITY wavefront sensor with light in the 1.4 to 2.4 micrometer band, while suppressing laser light originating from the GRAVITY metrology system, custom-built optical components are required. In this paper, we present the development of a quantitative near-infrared point diffraction interferometric characterization technique, which allows measuring the transmitted wavefront error of the silicon entrance windows of the wavefront sensor cryostat. The technique can be readily applied to quantitative phase measurements in the near-infrared regime. Moreover, by employing a slightly off-axis optical setup, the proposed method can optimize the required spatial resolution and enable real time measurement capabilities. The feasibility of the proposed setup is demonstrated, followed by theoretical analysis and experimental results. Our experimental results show that the phase error repeatability in the nanometer regime can be achieved.
Active or adaptive optics Active or adaptive optics Wave-front sensing Wave-front sensing interferometry interferometry Diffraction theory Diffraction theory Fringe analysis Fringe analysis Metrological instrumentation Metrological instrumentation Collection Of theses on high power laser and plasma physics
2013, 11(1): 9069
