Interferometric tolerance determination for a Dove prism using exact ray trace

We use exact ray trace to calculate the interferometric Dove prism tolerance to manufacturing errors. We model the manufacturing errors by modifying the position of the prism vertices. The normal to the prism faces establishes the direction of the rays. We determine the prism tolerance by analyzing the optical traversed path rays. We evaluate the change in the image quality introduced by the normal deviation. When the manufacturing tolerance is maintained within ±0.35 arc sec, the maximum wave-front deviation is better than λ/10 at 633 nm. We found that a Dove prism with such tolerance introduces an OPD of two orders of magnitude lesser than a commercial Dove prism. The exact ray trace accuracy of the developed program is validated with the commercially available optical-design program OSLO™. The calculated tolerance complements a previous analysis of a Dove prism for its implementation in a rotationally shearing interferometer.     

道威棱镜的偏振特性及偏振补偿研究

为了避免机载光电吊舱中共口径光学系统内部由于道威棱镜旋转引起的激光照射脉冲偏振态的变化,利用琼斯矩阵对道威棱镜的偏振特性与四分之一波片、半波片补偿道威棱镜旋转引起的激光脉冲偏振态变化进行了理论分析和实验验证。结果表明:线偏振的激光脉冲通过旋转一定角度的道威棱镜时,激光脉冲偏振态变为椭圆偏振,偏振态发生变化;而激光脉冲首先通过旋转一定角度的四分之一波片与半波片时,可使通过道威棱镜系统的激光脉冲偏振态保持不变,且两波片旋转角度与道威棱镜旋转角度之间存在一种非线性关系。采用偏振补偿方法可有效避免机载共口径光学系统中道威棱镜引起的激光脉冲偏振态变化,提高激光脉冲能量利用率,降低激光脉冲后向散射抑制难度。     

Polarization transforming properties of Dove prisms

We analyze the polarization changes introduced by a rotated Dove prism on the linearly polarized light, using the Jones calculus and the exact ray trace analysis. The state of polarization changes from the linear to a mildly elliptical one when a plane wave front passes through a rotated Dove prism: its semi-major axis is nearly parallel to the input plane of polarization, for any angle of prism rotation. The interferogram contrast remains high for all shearing angles in spite of polarization changes when the Dove prism is incorporated into a rotational shearing interferometer. These results are confirmed experimentally.     

Sorting and detecting orbital angular momentum states by using a Dove prism embedded Mach-Zehnder interferometer and amplitude gratings

An experimental system consisting of a Dove prism embedded Mach-Zehnder (M-Z) interferometer and two gratings was built to sort and detect orbital angular momentum (OAM) states of light beams. The helical beams with different OAM states were generated by propagating the fundamental-mode Gaussian beam through a spatial light modulator. The Dove prism embedded M-Z interferometer was used to sort helical beams with odd or even OAM number and two binary amplitude gratings were used to measure the OAM states. Sorting of coaxially-superposed coherent and incoherent helical beams with odd and even OAM states was realized in the experiment.     

用于角膜放射状切开手术的准分子激光器和光束投射系统

介绍了用于角膜放射状切开手术的准分子激光器和光束投射系统.得到宽0.14mm长8mm的狭缝光束.能量密度大于200mJ/cm~2.用Dove棱镜可使光束旋转.这个光学投射系统适合于动物角膜放切研究.     

Optical levitation of absorbing particles with a nominally Gaussian laser beam

We use a Gaussian laser beam to study the levitation of absorbing Mie particles. Several metal oxide particles are stably levitated, and their movement over time is recorded. Our studies show that the position of each particle is highly dependent on the other particles' locations. The observations are explained by the phenomenon of thermal creep. The increased local pressure that is due to a temperature gradient along the particle's surface induces levitation. The particles rest close to minima in the intensity distribution near the optical axis. An experiment is suggested that can be used to locate these minima in a laser beam.     

球棱镜及其应用

现代科技的迅速发展促进了非共轴光学系统的发展和日益广泛的应用。球棱镜是非共轴光学系统常采用的光学元件之一。合理采用球棱镜元件可以设计出一系列具有不同用途的光学系统。它们具有尺寸小、重量轻、结构紧凑等特点，并且具有共轴光学系统难以达到的一些光学性能，因而也拓宽了光学系统的应用范围。本文从非共轴光学系统出发，对球棱镜的种类和性能特点进行了阐述，并介绍了其在非共轴光学系统中的几种应用。     

平行光路中的三轴稳像反射镜组

在对立方棱镜的结构特性和阿贝棱镜的成像特性分析的基础上 ,提出了由反射镜组成的三轴稳像反射镜组 ,并推导了该三轴稳像反射镜组在平行光路中的稳像公式。该三轴稳像反射镜组具有体积小和适合于所有光谱范围等特点。     

利用Sagnac干涉仪实现光子轨道角动量分束器

光子轨道角动量量子态具有高维和光学涡旋特性, 在经典和量子领域展示出了巨大的应用潜力, 目前对其的研究已成为物理学的一个热点. 本实验研究了利用Sagnac干涉仪干涉的方法将具有不同轨道角动量的光束无破坏地分离到不同的路径, 即实现光子轨道角动量分束器. 实验中利用此分束器验证了对几种不同轨道角动量态(包含叠加态)的分离, 得到了与理论预期相符的实验结果. 这种对轨道角动量态的区分的方法相比已有的其他区分方法具有较好的稳定性, 而且可用于区分叠加态, 也可以达到单光子水平, 最重要的是实现了不同的轨道角动量本征态无破坏的与路径比特耦合. 这种新方法对高密度通信、量子纠缠、量子保密通信、量子计算与量子信息等方面有着重要的意义.     

Research on DMD infrared scene projector with a high contrast ratio infrared prism design

In this paper a single-DMD infrared scene projector with a high contrast ratio prism design of the illumination optical system is presented. By using the innovative infrared three-element TIR prism group, the off-state and flat-state light that reflected by the DMD could be all steered away from the projection lens. The contrast ratio and optical efficiency has been improved with this three-element TIR prism as the light-separator. This DMD infrared scene projector also features low-profile and compact structure. The illumination and projection optical systems are proved to be of great efficient light utilization. In this letter we analyze the impacts of optical efficiency on temperature simulation. This architecture with three-element TIR prism added could be used in IRSP based single-DMD to improve contrast and optical efficiency.     

稳像光学系统设计

重点沦述光学稳像的光学原理,并引用具体的平面反射镜作为光学补偿元件(也就是光稳元件)的稳像方式加以阐述,由此导出倒像系统和正像系统达到相对稳像和绝对隐像时补偿角与扰动角之间的关系式。论述采用会聚光路稳像时由棱镜的微量转动而达到绝对稳像时棱镜转动中心的求法。论述光稳元件兼作转像棱镜时光稳元件的有效孔径与转功中心和棱镜位置的关系。     

消色差的1/4波长延迟器的几何光学设计

在许多光谱学测量和实验研究中,常需要一个消色差1/4波长延迟器来满足各种实验测量条件.这可以通过一个在工作波长范围内折射率变化较小的菱型棱镜来实现.为了使用方便,在光学系统中可设计一个具有三个全内反射面的V型棱镜,其总的相位延迟达90°,同时可避免光路偏差.在实际应用中,需对棱镜的尺寸和通光孔径进行优化设计,以达到最佳效果.在本文中,我们给出了具有这种结构的几何设计例子,还结合不同参量成功地设计研制了一个消色差的1/4波长延迟器,并应用于磁光材料的克尔效应测量中.文中给出了详细计算和误差修正,所给出的计算公式可用于其他尺寸的消色差1/4波长器的设计和研制.     

Tunable optofluidic aperture configured by a liquid-core/liquid-cladding structure

Miniaturized and tunable optical components, such as the waveguide, lens, and prism, have been of great interest for lab-on-chip systems. This Letter reports an optofluidic aperture stop formed by the liquid-core/liquid-cladding flow. The aperture size can be tuned accordingly by adjusting the flow rates. Manipulation of the aperture size allows control of the amount of light passing through the corresponding optical system as well as the angular aperture on the image side. This optofluidic aperture enables lab-on-chip optical systems to have a greater flexibility and more functionalities.     

Deterministic qubit transfer between orbital and spin angular momentum of single photons

In this work we experimentally implement a deterministic transfer of a generic qubit initially encoded in the orbital angular momentum of a single-photon to its polarization. Such a transfer of quantum information, which is completely reversible, has been implemented adopting an electrically tunable q-plate device and a Sagnac interferometer with a Dove prism. The adopted scheme exhibits high fidelity and low losses.     

Single-lens camera based on a pyramid prism array to capture four images

An optical design with a pyramid prism array is employed to simultaneously capture four images. The apex angle design of an upper and lower prism array is to form the upper and the lower images of the object. The design of the left and right prism array is to develop the left and right images. In the prism array, the unwanted image can be eliminated by blacken process in the plane gap between each prism. The optical design was based on the pyramid prism array and a single-lens to make the system light, portable and low-cost.     

某型号周视镜总体设计技术分析

为了扩大观察范围,模块化结构单元,提高可靠性,设计了一款多功能周视镜。利用滚珠丝杠和直线轴承实现头部升降,扩大产品的观察范围;利用齿轮组差动技术实现上反射镜运动传输,保证系统可靠性;利用步进电机驱动道威棱镜及配合绝对值式光电编码器反馈角值位置信息,消除周视过程中的图像旋转,保证系统观瞄和测角精度。实验结果表明:周视镜可昼夜观瞄、昼间3～6连续变焦、头部升降300 mm、方位向全周视、测角精度在连续转动下不低于1 mard。     

Effect of spatio-temporal coupling on ultrafast laser direct writing in glass

Spatio-temporal coupling characteristics of ultrafast laser pulses are quantitatively tailored. An asymmetric microstructure is induced in the focal volume when the laser scans perpendicularly to the direction of the spatial chirp in fused silica. The tilted direction reverses when adding a Dove prism into the light path. The sign of the pulse front tilt can be turned from positive to negative by changing the group delay dispersion by steps. We reveal that the tilted direction of a microstructure depends on spatial chirp, and the interplay between spatiotemporal chirp leads to the change of tilted angles.     

A displacement measurement system, utilizing a Wollaston interferometer

A dual interferometric displacement measurement system is presented where a Wollaston prism interferometer is employed in conjunction with a normal Michelson interferometer. The system operates without the use of external polarizers, apart from those associated with the Wollaston prism interferometer itself. It is shown that an optical path difference induced in the Michelson interferometer can be detected using the Wollaston prism in a normal interferometer arrangement. Further, the interference pattern produced by the Wollaston prism interferometer changes in a measurable, linear fashion as the optical path difference from the Michelson interferometer alters. A simple theoretical analysis of the system is presented and used to derive a computer model of the optical arrangement. Results from an experimental implementation of the system, using a Wollaston prism with a beam separation of 0.5 degrees and a superluminescent diode, of wavelength 825 nm, as a light source, are included and compared to the results from the computer model.     

基于差分光密度差异的组织内异质体的快速定位方法

基于近红外光谱法对组织内的异质体进行无创检测时,光源-探测器(S-D)相对于异质体的位置对检测效果有着重要影响。为实现对组织内异质体的快速定位,该研究基于一源多探的检测结构针对不同水平位置、不同深度和不同直径的异质体进行光密度分布有限元分析,计算各探测器之间的差分光密度差异。仿真实验结果表明,根据多探测器形成的差分光密度差异曲线可快速定位组织内异质体的水平位置。曲线的高斯拟合特征量与异质体的水平位置、深度和直径有着强相关性。基于差分光密度差异曲线可以实现组织内感兴趣区域的快速定位,对采用近红外光谱法的组织肿瘤检测、光学脑功能成像等领域的源-探位置放置提供重要参考,提高其检测精度。