Low drift nuclear spin gyroscope with probe light intensity error suppression

A nuclear spin gyroscope based on an alkali-metal–noble-gas co-magnetometer operated in spin-exchange relaxationfree(SERF) regime is a promising atomic rotation sensor for its ultra-high fundamental sensitivity. However, the fluctuation of probe light intensity is one of the main technical error sources that limits the bias stability of the gyroscope. Here we propose a novel method to suppress the bias error induced by probe light intensity fluctuations. This method is based on the inherent magnetic field response characteristics of the gyroscope. By the application of a bias magnetic field, the gyroscope can be tuned to a working point where the output signal is insensitive to probe light intensity variation, referred to herein as ‘zero point’, thus the bias error induced by intensity fluctuations can be completely suppressed. The superiority of the method was verified on a K–Rb–21 Ne co-magnetometer, and a bias stability of approximately 0.01°/h was obtained. In addition, the method proposed here can remove the requirement of the closed-loop control of probe light intensity, thereby facilitating miniaturization of the gyroscope volume and improvement of reliability.

Zemax-Based Optimum Structural Design of Probe of an Optical-Fiber Sensor

Bubble plumes are important during the process of air-sea exchange,and optical-fiber phase detection is a suitable way to observe bubble plumes entrained by breaking waves.This paper designs a new optical-fiber probe(OFP)made of sapphire to overcome the limitations of existing materials(e.g.,high brittleness,poor corrosion resistance,and narrow bandwidth)and thereby enhance the detection performance of the OFP by improving its structure.Based on total internal reflection and light refraction,a simulation model of the probe is established in the Zemax optical design software to optimize the probe tip and matching mode of the two probe tips.The results show that the optimum OFP tip is a conical sapphire one with a cone angle of 35°.Tests are then conducted on a bespoke OFP sensor,the results of which are consistent with those predicted theoretically.The simulation results lay the foundation for the integrated design of OFP sensors and the optimization of their internal optics.The findings could also be applied to OFPs with multiple tips.

Testing of NAPL simulator to predict migration of a light nonaqueous phase liquid(LNAPL) under water table fluctuation in a sandy medium

Nanoqueous phase liquid(NAPL) simulator is a powerful and popular mathematical model for modeling the flow and transport of non-aqueous phase liquids in subsurface,but the testing of its feasibility under water table fluctuation has received insufficient attention.The feature in a column test was tested through two cycles of water table fluctuation.The sandy medium in the column was initially saturated,and each cycle of water table fluctuation consisted of one water table falling and one rising,resulting in a drainage and an imbibition of the medium,respectively.It was found that the difference between the simulated and measured results in the first drainage of the column test was minor.However,with the propagation of the water table fluctuations,the simulation errors increased,and the simulation accuracy was not acceptable except for the first drainage in the two fluctuation cycles.The main reason was proved to be the estimation method of residual saturation used in this simulator.Also,based on the column tests,it was assumed that the resulting residual saturation from an incomplete imbibition process was a constant,with a value equal to that of the residual value resulting from the main imbibition process.The results obtained after modifying NAPL simulator with this assumption were found to be more accurate in the first cycle of water table fluctuation,but this accuracy decreased rapidly in the second one.It is concluded that NAPL simulator is not adequate in the case of LNAPL migration under water table fluctuation in sandy medium,unless a feasible assumption to estimate residual saturation is put forward.

Noise Reduction in White Light Lidar Signal Using a One-Dim and Two-Dim Daubechies Wavelet Shrinkage Method

A 1-D and 2-D Daubechies 5 (db5) discrete wavelet shrinkage methods using a 10 level decomposition was applied to white light lidar data particularly at 350 nm and 550 nm backscattered signal. At 350 nm, the backscattered signal is very weak as compared to 550 nm backscattered signal because of the spectral intensity distribution of the generated white light. The 1-D and 2-D wavelet shrinkage method gave a much better result as compared with the moving average method. However, the 2-D wavelet shrinkage method produced a much better denoised lidar signal compared with the 1-D wavelet shrinkage method. This is indicated by the 142% increase in correlation coefficient between the 2-D denoised lidar signal and the 800 nm original lidar signal as compared with only 12% increase in correlation coefficient for the 1-D denoised lidar signal. The 2-D wavelet shrinkage method also gave a much higher SNR value of 65.9 compared to 1-D which is 38.8.

Ultrafast optical beam deflection in a pump probe configuration

Propagation of a signal beam in an Al Ga As/Ga As waveguide multiple-prism light deflector is theoretically investigated by solving the scalar Helmholtz equation to obtain the dependences of the temporal and spatial resolvable characteristics of the ultrafast deflector on the material dispersion of Ga As including group velocity dispersion and angular dispersion,interface reflection,and interface scattering of multiple-prism deflector.Furthermore,we experimentally confirm that,in this ultrafast beam deflection device,the deflecting angle of the signal light beam is linear with the pump fluence and the temporal resolution of the ultrafast deflection is 10 ps.Our results show that the improvement of the temporal and spatial resolvable performances is possible by properly choosing the structural parameters and enhancing the quality of the device.

接触式与白光干涉测头复合测量坐标统一与数据融合

针对复合测量中两测头空间坐标系不统一的问题,提出了基于标定器提供基准点结合单位四元数法求解空间变换矩阵的坐标统一方法,并以均方根误差(RMSE)来评估坐标统一的效果。设计并制作了一种新型标定器,为坐标统一提供稳定可靠的基准点,并建立了基准点精度与坐标统一精度的关系模型。针对两测头测量数据,提出了空间误差椭球搜索策略结合加权最小二乘法的数据融合方法。实验结果表明,复合测量的坐标统一化配准精度可达1.889μm,所提出的数据融合方法相较传统加权最小二乘法的相对误差减小了16%,重复性精度提高了38%,实现了复合测量的高精度坐标统一与稳定精确的数据融合,提升了对器件的测量能力。

我国深空探测器数据管理技术发展

数据管理(简称数管)分系统是深空探测器平台的重要分系统,将探测器测控任务综合在一个以计算机系统为主的系统中,为探测器平台和有效载荷提供全面、综合的服务与管理。文章论述了在我国深空探测器(嫦娥一号到嫦娥六号月球探测器、天问一号火星探测器)任务实施过程中数管技术的发展历程及其应用情况;其中形成的针对深空探测器的高可靠、集成化、智能化、网络化的数管技术体系,为未来深空探测器任务顺利实施奠定了技术基础。展望后续深空探测器的发展,给出了数管技术在智能自主管理技术等方面的发展建议。

一维摄像机的线结构光测头标定方法

为了解决传统的线结构光标定过程步骤繁琐并且准确度不足的问题,提出了把线结构光的光刀平面建立模型为一维摄像机的测头标定方法。首先从线结构光的光条中心提取坐标信息,并计算其在标定靶上的位置坐标,接着依据至少两组姿势下的光条中心的三维坐标点来建立拟合平面方程,最后构建虚拟一维摄像机来表示光刀平面。通过进行迭代摄像机标定和线结构光测头标定,再结合三角测量技术,可获得在立体视觉模型中的被测物的三维点云数据坐标。经实验测试,对两个有高低差异的量块进行了测量,重复10次标定实验,结果显示迭代摄像机标定的平均误差为0.077 220 pixel,光刀平面标定的平均误差为1.415 17 mm,这个试验表明了这种线结构光测头标定的方法有着较高精度,是可行的。

探测几何反射光谱测量系统设计

地物反射光谱是地面遥感的基础,现有的测量装置多基于复杂的机械传动平台与控制系统,整体结构庞大笨重、成本较高、便携性差。为解决上述问题,该文设计了一种探测几何反射光谱测量系统,该系统主要由探测几何支架、光谱采集系统、卤钨聚光光源、载物台四个部分组成,探测几何支架采用模块化设计,通过各组成模块的灵活装配定位,可实现较大的角度、距离探测几何范围,该系统采用一分多光纤,可实现较大的光谱波段覆盖范围。通过对该系统的试制与调试,以及地物样品光谱采集测试实验,验证了其探测几何及波段范围。该系统结构简单、互换性好、安装携带方便、实用性较强、满足室内与野外使用需求的特点。

多波长自外差检测布里渊光时域反射系统

为了减小相干瑞利噪声,提出了一种多波长瑞利和布里渊自外差检测布里渊光时域反射系统。分析了相位调制产生多波长探测光的机理及三波长系统的自外差检测原理;搭建单波长和三波长自外差检测布里渊光时域反射系统,获得了沿光纤的自外差信号功率和布里渊频移。实验结果表明,相对于单波长系统,三波长系统有效地减小了相干瑞利噪声引起的功率波动,信噪比提高近4.56dB;布里渊频移波动的均方根误差降低2.2 MHz。

单目视觉测量技术研究

对单目视觉测量方法进行了研究、分析,其中包括几何相似法、几何形状约束法、结构光法、辅助测量棒法和激光辅助测距法。结合作者最新的研究成果,重点对结构光法和辅助测量棒法测量作了介绍。

有机染料作为光散射探针在分析应用中的研究进展

结合本实验室的研究工作 ,对有机染料作为光散射探针在蛋白质、核酸和金属离子测定中的应用进行了系统的评述 .结合光散射原理及有机染料的共振光散射增强理论 ,对实验中出现的现象作出解释 。

点光源测头光束方向的标定

指出在采用点光源测头测量物面测点坐标时 ,因光束方向相对于机床坐标系的安装偏角而引起的测量误差问题。提出了一种标定光束方向的方法。设计 V形块做标定的靶标平面 ,通过在 V形块随各坐标轴做等距移动时采样 ,实现了点光源测头光束方向的标定。给出了标定光束方向后的测点坐标计算方法。并设计了仿真程序验证了该方法的可行性。仿真结果表明 ,当测头精度为 0 .0 1m m,光栅尺对机床位移的检测精度为 0 .0 0 2 mm时 ,光束方向的标定误差可以控制在 0 .

一种新型的测量汽轮机内湿蒸汽两相流的集成化探针系统

汽轮机内湿蒸汽两相流中一次、二次水滴的参数和流场是密切相关的，但国内外迄今没有能同时测量这些参数的技术和设备。作者成功研制了能同时测量湿蒸汽两相流中一次、二次水滴和流场的集成化探针。该探针已在３５０ＭＷ汽轮机上进行了实测。本文介绍了该测量系统的原理和构成。

两种荧光探针法研究三种非甾体抗炎药与DNA的相互作用

采用溴化乙锭(EB)和中性红(NR)两种荧光探针分别考察了三种非甾体抗炎药(吲哚美辛、舒林酸和托美丁)与DNA的相互作用,采用荧光发射光谱和共振散射光谱技术得出了基本一致的结论:吲哚美辛和舒林酸可以在一定程度上与DNA结合(舒林酸更强),结合方式可能有嵌插作用,也可能有药物分子在DNA双链表面的组装,作用力来源于静电作用.而托美丁几乎不与DNA作用,因为其疏水性弱,与DNA分子结合几率小.

磁纳米探针检测人绒毛膜促性腺激素

采用链霉亲和素包被磁纳米粒子,将生物素标记的特异性抗体偶联在磁纳米粒子上,制备出高特异性的磁纳米探针;利用此探针对人绒毛膜促性腺激素(HCG)进行测定,建立了定量检测蛋白类激素的化学发光分析方法。利用紫外可见分光光度计、透射电镜及动态光散射仪对磁纳米探针进行表征,同时对化学发光实验条件进行优化。在2×10-4mol/L鲁米诺、8×10-4mol/L H2O2,pH=13的优化条件下,将磁纳米探针用于HCG的定量检测。结果表明,所测发光强度与待测HCG浓度之间线性相关,相关系数r为0.9924,线性检测范围由常规板式ELISA的5～200μg/L扩展到0.5～250μg/L;相对标准偏差为3.82%。采用本方法和常规ELISA法同时对34份人血清标本HCG进行测试,两者相关性良好。利用制备的磁纳米探针定量测定微量蛋白类激素,具有灵敏、高效、快捷、检测范围宽等优点,有望应用于其它微量蛋白的检测。

溴化乙锭探针研究劳氏青莲与脱氧核糖核酸的相互作用

用光谱探针溴化乙锭对劳氏青莲与脱氧核糖核酸的作用机制进行了研究。通过对体系的荧光光谱、吸收光谱及共振光散射光谱等方面的研究,结果表明,在pH为7.4的Tris-HCl缓冲溶液中,劳氏青莲与脱氧核糖核酸之间存在着嵌插作用,其结合常数为1.0×105L.mol-1。

新型光功能稀土配合物研究及应用进展

稀土配合物独特的光物理性质决定其在发光器件、荧光探针等领域具有重要应用前景,因而受到广泛关注。本文总结了光功能稀土配合物研究的相关研究进展,梳理了相关的稀土配合物的光物理性质和发光机理理论,重点总结了近年来稀土配合物在有机电致发光器件、荧光探针等领域的研究进展,并对其未来的应用和研究进行了展望。

透明软质薄膜的表面形貌测量

为了实现光刻胶表面形貌的广域、高精度测量,对新一代测量理论及测量方法进行了研究。首先分析了被测物件的特性,根据其柔软、透明的特征提出应用光干涉法和机械探针相结合的方法进行测量,同时阐明了使用此方法进行表面形貌测量的优点,并据此原理搭建了光学多探针表面形貌测量装置,光学测量部分采用白光干涉计,探针部分采用拥有8只球型探头的多点悬臂测量探针。然后应用此装置对标准刻槽试件和半透明光造型薄膜试件进行了测量。测量52 nm的标准刻槽试件时得到了测量误差小于2%,标准偏差小于1 nm的结果,表明本装置可以达到高精度测量表面形貌的目的。通过测量高约400 nm的树脂材料证实了此装置可以克服多重反射的影响测量透明薄膜的表面形貌。

复合型超精密表面形貌测量仪

研制了基于同一显微镜基体实现原子力探针扫描测量与非接触光学测量两种功能的复合型超精密表面形貌测量仪。分析了基于白光显微干涉原子力探针的测量方法、探针微悬臂变形量与白光干涉条纹移动量的关系以及探针微悬臂测量非线性误差的修正方法,和通过融合垂直扫描系统的位移量和悬臂梁变形量得到了原子力探针的工作方式。研制了三维精密位移系统和基于白光显微干涉的原子力探针测头。采用原子力探针扫描测量对NT-MDT公司生产的扫描探针校准光栅TGZ2_PTB进行了重复性实验,实验显示标准差为0.96nm,相对重复性误差为3.08%。给出了原子力探针扫描测量、相移干涉测量及白光干涉垂直扫描测量的测量实例。实验结果表明,所研制的超精密表面形貌测量仪可用于超精密加工工程表面、光学表面以及微纳几何结构的测量。