Author Affiliations
Abstract
1 CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China
2 CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
3 Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
Modulation of a vector light field has played an important role in the research of nanophotonics. However, it is still a great challenge to accurately measure the three-dimensional vector distribution at nanoscale. Here, based on the interaction between the light field and atomic-sized nitrogen-vacancy (NV) color center in diamonds, we demonstrate an efficient method for vectorial mapping of the light-field distribution at nanoscale. Single NV centers with different but well-defined symmetry axes are selected and then interact with the same tightly focused light field. The excitation of a single NV center is related to the angle between the NV center axis and the polarization of the light field. Then the fluorescence patterns of different NV centers provide the information on the vectorial light field distribution. Subsequently analyzing the fluorescence patterns with the help of a deep neural network, the intensity and phase of the light-field vectorial components are fully reconstructed with nanometer resolution. The experimental results are in agreement with theoretical calculations. It demonstrates that our method can help to study light–matter interaction at nanoscale and extend the application of vector light fields in research on nanophotonics.
light-field measurement nitrogen-vacancy center tightly focused light field Chinese Optics Letters
2023, 21(7): 071202
1 首都师范大学物理系, 北京 100089
2 中国计量科学研究院时间频率计量科学研究所, 北京 100029
介绍了一种自主搭建的测量落体在自由下落过程中旋转角速度的装置,评估了不同落体旋转角速度引入的旋转误差对重力测量的影响。针对具有旋转初速度的落体在真空腔内自由下落的运动模型,该装置采用光杠杆原理,将高精度位置传感器(PSD)作为光跟踪设备,研究并推导出落体由旋转所导致的反射光位移与下落时间的关系。然后,对PSD采集记录的时间位移曲线进行拟合,求解落体单次下落的旋转角速度值。在调整真空腔垂直度后,最大旋转角速度值可减小为16.88 mrad/s,引入的重力测值不确定度为0.57 μGal,即该状态下落体的释放更加平稳。实验表明,该装置不仅可以进一步提升绝对重力仪中落体传动机构的装调精度,还可以对光学干涉绝对重力仪工作过程中的落体姿态进行监测,进一步降低落体旋转所引入的测量不确定度。
测量 计量仪器 光学干涉绝对重力仪 落体旋转误差 光杠杆原理 角速度测量
为了减小自由落体式光学干涉型绝对重力仪中光束垂直度对重力测量准确度的影响, 提出了一种基于双层液体光楔对光束的可变偏折实现光束垂直性自校正的快速调节方法。当光束偏离铅锤方向时, 利用液面天然水平的特性, 使液体在重力的作用下形成可变液体光楔, 自上而下的光束经双层液体光楔时光束传播方向发生偏转, 合理地匹配双层液体的折射率, 使它偏离铅锤方向的夹角得到实时修正。搭建光束垂直性自校正装置并进行实验验证, 结果表明, 装置的角度抑制比优于18.0, 当装置倾斜角度不大于2.7′时, 出射光束偏离铅锤方向不超过9.0″, 对应于重力加速度的测量误差小于1 μGal (1 μGal=10-8 m/s2)。将本方案用于自由落体式的重力加速度测量, 仅通过条式水平仪调平便可实现光束垂直性的快速准确调节, 同时还能抑制测量过程中光束垂直性缓变带来的影响。
绝对重力仪 光楔 光束垂直性 激光干涉仪 自校正 absolute gravimeter optical wedge beam verticality laser interferometer self-correction
Author Affiliations
Abstract
1 Institute of Optics, Department of Physics, Zhejiang University, Hangzhou 310027, China
2 Center for Optics and Optoelectronics Research, College of Science, Zhejiang University of Technology, Hangzhou 310023, China
The first Asia-Pacific Comparison of Absolute Gravimeters (APMP.M.G-K1) was organized by the National Institute of Metrology (NIM) of China from December 21, 2015 to March 25, 2016 in Changping, Beijing. Our compact cold atom gravimeter (CCAG) was transported from Hangzhou to Beijing with a long distance of about 1200 km to participate in this comparison. The CCAG is the only one, to the best of our knowledge, that is based on the principle of atom interferometry among all the instruments. Absolute gravity in the indicated three test sites has been measured as requested by the organizer. The sensitivity of our CCAG is estimated to be 90 μGal/Hz, even when the measurements are carried out without any vibration isolation. Besides, the accuracy of this gravimeter has been evaluated to be about 19 μGal by considering the significant system errors. Our results show a good agreement with the given reference value.
120.3180 Interferometry Chinese Optics Letters
2019, 17(1): 011204
哈尔滨师范大学物理与电子工程学院， 黑龙江 哈尔滨 150025
由耦合模理论分析得出，光纤布拉格光栅反射偏振相关损耗峰值位置对于温度和侧向力的作用有不同的响应特性。可通过相关灵敏度系数矩阵，用单根光纤光栅实现对温度和侧向力的同时测量，此方法解决了温度应力交叉敏感问题。实验测得反射偏振相关损耗左峰和右峰的温度灵敏度分别为0.0101 nm/℃和0.0100 nm/℃，侧向力灵敏度分别为0.0071 nm/N和0.0005 nm/N，温度和侧向力测量精度分别为±1 ℃和±0.6 N。此方法具有核心传感元件简单、稳定性好、易于埋入被测材料内部进行实时监测等优点，是一种检测材料内部结构和环境温度变化的新方法。
光纤光学 光栅 反射偏振相关损耗 温度 侧向力 中国激光
2012, 39(12): 1205003
1 哈尔滨师范大学 物理与电子工程学院, 哈尔滨 150025
2 齐齐哈尔医学院 医学技术学院, 黑龙江 齐齐哈尔 161006
理论分析了切趾弱双折射光纤布喇格光栅反射偏振相关特性与温度之间的关系.数值模拟了切趾弱双折射光纤光栅的反射谱、偏振相关损耗和差分群时延随波长变化曲线.实验测出了不同温度下反射谱、偏振相关损耗和差分群时延随波长变化曲线.根据实验结果对偏振相关损耗和差分群时延的变化情况作出了分析.反射偏振相关损耗呈现两个峰值，随温度增加两峰漂移程度相同，表明偏振相关损耗无明显差异.差分群时延最大值随温度增加成线性向长波方向漂移，证明了光纤光栅正交模损耗变化的等同性.综合理论分析与实验结果表明：切趾弱双折射光纤布喇格光栅的偏振特性随温度产生明显的变化，其正交模变化呈现等比例特性.
光纤布喇格光栅 双折射 偏振相关损耗 差分群时延 Fiber Bragg grating Birefringence Polarization dependent loss Differential group delay
哈尔滨师范大学物理与电子工程学院， 黑龙江 哈尔滨 150025
根据耦合模理论，深入研究了横向压力作用下光纤布拉格光栅(FBG)的反射偏振相关损耗(RPDL)特性，对不同横向压力下的RPDL分别进行了数值模拟。模拟结果表明，RPDL对横向压力的响应非常敏感，压力变化时其峰值高度和主峰位置均发生较大的变化。对此进行大量的实验验证，实验结果与理论分析相符；并且实验结果显示RPDL峰高变化和峰位变化曲线在一定范围内均呈很好的线性关系。从而可以利用RPDL特性实现对外力场信息变化的灵敏监测。
光栅 偏振相关损耗 耦合模理论 横向压力
