Three-dimensional dynamic optical manipulation by combining a diffractive optical element and a spatial light modulator

Since the introduction of computer-controlled spatial light modulators (SLMs), holographic optical tweezers have become an important tool for dynamic parallel optical manipulation. In this paper we clarify the usefulness of a new configuration for optical trapping that creates light patterns using the combination of a diffractive optical element (DOE) and an SLM. This configuration not only enables the use of the higher part of the SLM’s diffraction efficiency curve, because a simple hologram can be chosen for the SLM, but also achieves three-dimensional dynamic optical manipulation over a large spatial range. By switching blaze-like holograms displayed on the SLM, we demonstrated simultaneous transportation of three 6-μm-diameter polystyrene beads over a range of 90 μm in the vertical direction and 37.5 μm in the horizontal direction. Compared with the same manipulation executed using only the SLM, the range of this method is extended four-fold in the vertical direction and three-fold in the horizontal direction.     

Optical manipulation of gold nanoparticles using an optical nanofiber

Gold nanoparticles are gaining increasing attention due to their biological and medical applications.In this letter,we experimentally demonstrate the optical manipulation of 250-nm-diameter gold nanoparticles along an optical nanofiber(550 nm in diameter) injected by an 808-nm laser light.The nanoparticles situated in the evanescent optical field are trapped by optical gradient force and move along the direction of light propagation due to optical scattering force.The velocities reach as high as 132 μm/s at an optical power of 80 mW.     

Optical manipulation at planar dielectric surfaces using evanescent Hermite-Gaussian light

We show that a set of high order Hermite-Gaussian light beams when internally reflected at a dielectric/vacuum interface can generate well-defined evanescent light modes in each of which the intensity distribution is confined to a sub-wavelength region near the interface outside the dielectric. We suggest that this could greatly facilitate lateral optical manipulation of nano-particles and neutral atoms along the interface. Equally significantly, the scenario could lead to the formation of two-dimensional optical potential arrays and surface optical lattices that could form a suitable architecture for the implementation of quantum computing using neutral atoms.     

激光投影显示中光棒匀光的照明光路设计

在方棒照明系统的基础上,根据激光光源的发光特性和准直性,设计了一款用于激光投影显示的,基于光棒匀光的照明光路系统。此系统具有结构简单、开发周期短、加工成本低的优点。仿真结果表明：设计的激光投影机光能量利用率达到78%,均匀度达到85%,满足激光投影显示中对集光和照明的设计要求。     

激光投影显示中光棒匀光的照明光路设计

在方棒照明系统的基础上,根据激光光源的发光特性和准直性,设计了一款用于激光投影显示的,基于光棒匀光的照明光路系统。此系统具有结构简单、开发周期短、加工成本低的优点。仿真结果表明:设计的激光投影机光能量利用率达到78%,均匀度达到85%,满足激光投影显示中对集光和照明的设计要求。     

Optical formation and manipulation of particle and cell patterns using a tapered optical fiber

A method for optical formation and controllable manipulation of particle and cell patterns using a tapered optical fiber is demonstrated. With a laser beam at 980‐nm wavelength launched into the fiber, different sized silica particles were formed into particle patterns (both one‐dimensional chains and two‐dimensional arrays) with different particle numbers by optical binding. The formed particle patterns can be controllably manipulated in three dimensions. Using yeast cells as an example, it was demonstrated that the method is applicable for the formation of biological cell patterns, without damage to the yeast cell viability. This method provides a new facile way for biophotonic and biological researches with particles and cells in a highly organized manner.     

Nonmechanical Optical Manipulation of Microparticle Using Spatial Light Modulator

A spatial light modulator (SLM) is introduced to an optical manipulation system. The real-time reconfigurable feature of the SLM makes it possible to perform an optical manipulation of microparticles without mechanical movements of optical parts. A liquid crystal SLM incorporated in the system forms a Fresnel zone plate (FZP). The beam spot generated by the FZP is imaged on a sample solution by reduction optics. A microparticle in the sample solution is trapped by the beam and manipulated by changing the addressing position of the FZP onto the SLM from a computer. The nonmechanical optical manipulation of microparticles is demonstrated for the first time.     

光拍频法测光速实验的改进

光速的测定是物理学中一个十分重要的课题,文章介绍光拍法测光速原理,结合现有实验仪器,对原有光拍频法测光速的公式加以变换,光速测量的精度有了很大提高。     

Generation of Circular Optical Vortex Array

We report on a novel optical vortex array named circular optical vortex array, which is generated by the superposition of two concentric perfect optical vortices. The circular optical vortex array has a constant topological charge of +1 or ?1, the number and sign of which are determined by the topological charges of the two perfect optical vortices. Moreover, the radius of the circular optical vortex array is easily adjusted by using the cone angle of an axicon. Furthermore, the circular optical vortex array and multiple circular optical vortex array can be rotated by changing the initial phase difference of the perfect optical vortices on demand. This work demonstrates a complex structured optical field, which is of significance for applications such as optical tweezers, micro‐particle manipulation, and optical imaging.     

光镊轴向阱位操控及器件安装误差对径向阱位操控的影响

光镊利用光学梯度力捕获和操控微小粒子,已经成为深入研究生物分子间相互作用等微观机制的独特技术.光镊光束操控系统一般由扩束输入镜、扩束输出镜、调焦透镜、耦合透镜和压电转镜等光学元器件组成,以保证物镜后瞳充满的前提下实现光镊阱位操控.光镊阱位的三维精确操控是实现光镊位钳和力钳模式的基本条件.本文根据矩阵光学,对基于无穷远校正显微镜的光镊操控光路进行计算,分析扩束输入镜、调焦透镜和物镜轴向位置调整,以及压电转镜、调焦透镜和耦合透镜安装位置误差对光镊径向阱位操控精度的影响,得到了物镜高度调整基本不会影响光镊径向位置操控,压电转镜和调焦透镜的安装位置误差对光镊径向阱位操控精度影响最大等结论,提出了能够实现径向阱位精确操控的轴向阱位动态操控范围,为光镊设计和操控提供理论和实验指导.     

光捕获和光操控研究进展

光捕获和光操控是一种通过光镊、倏逝波、光泳或光热等对微纳尺度颗粒、生物大分子和细胞等微小物体进行非接触、无损伤捕获和操控的方法和技术.详细归纳和总结了国际上在光捕获和光操控方面的研究进展和最新动态,分析了其今后的研究发展方向.     

光栅光阀光学特性分析及其在热敏CTP中的应用

光栅光阀(GLV)是一种衍射MOEMS空间光调制器,利用其对激光束的调制作用,可成功地应用于计算机直接制版(CTP)系统中。提出了简化的光栅光阀光学模型,并根据夫琅和费单缝衍射理论和多光束干涉理论对光栅光阀的光学特性进行了理论分析。介绍了光栅光阀在热敏CTP系统中的应用,分析了光栅光阀光学记录设备的结构和成像原理。得出了基于GLV技术的热敏CTP数字成像过程,为国内印刷企业使用这种热敏成像技术提供了理论依据。     

光镊技术在生命科学研究中的应用

介绍了光镊技术的工作原理和系统结构,论述了光镊技术工作特点,并结合具体的研究工作,阐述了光镊技术在单细胞、单分子等生命科学研究领域中的应用,最后给出了近年来光镊技术取得的进展和新的应用.     

光学读出红外成像中面光源影响下的光学检测灵敏度研究

在光学读出红外成像的理论分析中, 通常将具有一定实际尺寸的非相干面光源简化为理想点光源, 导致了分析误差. 本文建立了面光源模型, 通过夫琅禾费衍射理论, 研究了面光源影响下的光学检测灵敏度, 发现了光学检测灵敏度随光源半径和焦平面阵列反光板长度的变化关系, 提出了面光源影响下的光源尺寸和反光板长度的优化设计准则. 针对理论分析, 进行了实验验证, 测试结果与理论分析一致. 关键词： 面光源 光学读出 焦平面阵列 非制冷红外成像     

Spectral polarization-encoding of broadband laser pulses by optical rotatory dispersion and its applications in spectral manipulation

We propose a kind of spectral polarization-encoding(SPE) for broadband light pulses, which is realized by inducing optical rotatory dispersion(ORD), and decoded by compensating ORD. Combining with polarization-sensitive devices, SPE can not only work to control polarization-dependent transmission for central wavelength or bandwidth-tunable filtering, but also can be used for broadband regenerative or multi-pass amplification with a polarization-dependent gain medium to improve output bandwidth. SPE is entirely passive thus very simple to be designed and aligned. By using an ORD crystal with a good transmission beyond 3-μm mid-infrared region, e.g., Ag Ga S_2, SPE promises to be applied for the wavelength tuning lasers in mid-infrared region, where the tunning devices are rather under developed compared with those in visible and near-infrared region.     

光网络中的关键器件

光器件是光网中的基础单元之一。介绍了光网络中一些关键器件的重要特性及进展情况,讨论了光器件发展趋势。     

利用光杠杆测量微小位移的光路可视化研究与设计

通过对光杠杆测量微小位移装置进行改进,使光线的传播路径可以看见,便于学生理解实验原理,更快更好地进行仪器调整。     

连续变量量子态的光学操控

量子态的光学操控是指在光场的传输、存储和频率变换等过程中用光学方法对光场的量子态进行操作与控制.量子态操控是量子通讯及量子态制备和应用的基础.在简要介绍连续变量多组份纠缠态光场制备的基础上,概述基于多组份纠缠态光场的连续变量量子通讯网络及在执行压缩态和纠缠态光场操控方面的实验研究进展.     

单原子冷却及光学操控的实验进展

文章综述了基于原子冷却与俘获的单原子制备及其光学操控的基本实验原理及实验进展,并介绍了单原子制备及光学操控在量子寄存器、单光子源、原子-光子纠缠等方面的应用,简述了文章作者所在研究小组在单原子制备和光学操控方面的实验进展.     

Optical trapping and manipulation of micrometer and submicrometer particles

Subwavelength features in conjunction with light‐guiding structures have gained significant interest in recent decades due to their wide range of applications to particle and atom trapping. Lately, the focus of particle trapping has shifted from the microscale to the nanoscale. This few orders of magnitude change is driven, in part, by the needs of life scientists who wish to better manipulate smaller biological samples. Devices with subwavelength features are excellent platforms for shaping local electric fields for this purpose. A major factor that inhibits the manipulation of submicrometer particles is the diffraction‐limited spot size of free‐space laser beams. As a result, technologies that can circumvent this limit are highly desirable. This review covers some of the more significant advances in the field, from the earliest attempts at trapping using focused Gaussian beams, to more sophisticated hybrid plasmonic/metamaterial structures. In particular, examples of emerging optical trapping configurations are presented.