单频激光干涉仪四通道信号接收系统

在单频激光干涉仪四通道信号接收系统原理基础上,提出一种采用Wollaston棱镜的四通道信号接收系统。当使用偏振分光镜的四通道信号接收系统时,由于偏振混合现象,在信号接收的过程中会增加额外的误差。而Wollaston棱镜的自然物理特性提供了更好的分光性能,从而能降低偏振混合所带来的影响,提高了信号输出质量,并能简化接收系统中的光学元件。     

采用偏振分不棱镜的光桥式补偿技术

介绍了一种使用偏振分光棱镜的新型光桥式补偿技术，研究了棱镜消光比变化引起的误差。使用该补偿结构的光纤压力传感器实际应用于石油化工门油罐储量计量，其现场运行长期稳定性优于０．２％。     

采用偏振分光棱镜的光桥式补偿技术

介绍了一种使用偏振分光棱镜的新型光桥式补偿技术。研究了棱镜消光比变化引起的误差。使用该补偿结构的光纤压力传感器已实际应用于石油化工部门油罐储量计量，其现场运行长期稳定性优于０．２％。     

Wollaston棱镜方位对激光干涉测量精度的影响

在双频激光干涉测量系统中,Ｗｏｌｌａｓｔｏｎ棱镜是不可缺少的重要光学元件,它可将双频激光按偏振方向分为测量光和参考光,从而实现高精度测量;但是,如果Ｗｏｌｌａｓｔｏｎ棱镜的安装方位相对入射光线方向以及与聚集透镜距离不同时,测量结果将会不同。本文结合表面粗糙度激光测量系统,从理论上定量分析了Ｗｏｌｌａｓｔｏｎ棱镜的安装方位对测量精度的影响。     

Schmidt棱镜偏振像差的校正

为了校正Schmidt棱镜的偏振像差,消除双像和鬼影像现象,根据棱镜Jones矩阵B因子与衍射光强的关系,推导出B因子与屋脊面反射相移差δ之间的关系,明确了消除偏振像差,要求B=0需要屋脊面反射相移差δ=π的条件。采用在屋脊面镀制相位膜的方案,对比了单层膜与多层膜的反射相移差特性,得到了在可见光区实现宽波段消除偏振像差的膜系特性;证明了B=0是一条可以同时校正所有不同偏振状态入射光偏振像差的有效技术途径。实验镀制了屋脊面相位膜样品,进行了多种入射光偏振状态下的偏振像差检测,得到了很好的消偏振像差结果。     

基于机器视觉的保偏双尾纤装配精度检测

保偏光纤保持偏振状态的程度依赖于偏振光的入射状态,要保持偏振光的偏振态就要求偏振光的偏振态与保偏光纤慢(快)轴方向耦合对准.因此在保偏双光纤准直器中,双尾纤的(相对位置)装配精度直接影响保偏准直器的保偏性能.本文研究和分析了双尾纤的装配精度对保偏准直器保偏性能的影响,并指出双尾纤端面"猫眼"的垂直度是主要影响因素.基于机器视觉原理,通过生物显微镜、CCD摄像机,图像采集卡采集双尾纤端面的图像,建立"猫眼"垂直度的检测模型,由VB编程实现对图像的处理以及"猫眼"垂直度的检测,检测精度可达0.5度.该方法已在双纤保偏准直器工业装配中得到应用.     

棱镜折射率对光学加速作用的影响分析

针对所设计的棱镜Q开关,首次把棱镜的折射率考虑在内,将折射率对棱镜转镜Q开关光学加速作用的影响进行了详细的推导计算与分析.计算结果表明:考虑折射率影响后,相对于平面镜而言, 棱镜旋转速度会等效减小,说明折射率低的棱镜比折射率高的棱镜具有更明显的光学加速作用,即棱镜折射率对光学加速作用有一定负作用.因此,在选择光学加速装置时,除了要从反射损失小、易于加工等角度考虑外,还需将棱镜折射率因素考虑在内,以期获得最佳光学加速作用.     

波长校正调节螺杆调节的原理和方法

721型分光光度计采用自准式光路,单光束方法,其波长范围自360～800ｎｍ,用钨丝白炽灯泡作光源,其光学系统分光部分如图1。图1　光学系统分光部分图1.光源灯　2.聚光透镜　3.色散棱镜　4.准直镜　5.狭缝　　6.反射镜由光源灯发出的连续辐射光线,射到聚光透镜上,会聚后再经过平面转角90°,反射至入射狭缝,由此入射到单色器内,狭缝正好位于球面准直镜的焦面上,当入射光线经过准直镜反射后就以一束平行光射向棱镜(该棱镜的背面镀铝),光线进入棱镜后,就在其中色散,入射角为最小偏向角,入射光在铝面上反射后是依原路稍偏转一个角度反射回来,这样从…     

基于Zigbee的全站仪反射棱镜遥控装置研究

针对全站仪检定过程中,移动棱镜不方便的问题,研制出一种基于Zigbee的遥控反射棱镜装置。装置通过Zigbee实现无线传输,选取ATMEGA16作为控制芯片,通过按键以及无线传输将指令发送给接收端,接收端通过ATMEGA16芯片控制步进电动机的转动,从而实现对各个棱镜的控制。     

双Wollaston棱镜的光程差及其色散

深入研究了的光程差与棱镜楔角以及空间变量-入射角三者的关系,并进行了计算机模拟.发现了对方解石构成的双Wollaston棱镜,光程差有较大的变化范围,光程差和入射角的关系有较好的线性的条件是:棱镜楔角在22°附近,入射角在-50°到10°范围内变化.然后对光程差的色散特性进行了分析和计算机模拟,结果表明,双Wollaston棱镜的光程差明显依赖于光波长,根据拟合结果它们的关系可以用三阶多项式来表述.本结果为偏振型空间调制干涉光谱仪的设计和应用提供了理论依据.     

A photoexcited switchable perfect metamaterial absorber/reflector with polarization-independent and wide-angle for terahertz waves

We present a photoexcited switchable perfect metamaterial absorber/reflector for terahertz waves. The switchable absorber/reflector is based on a cross-shaped structure (CSS) integrated semiconductor photoconductive silicon (Si). The electric response property of the photoconductive Si can be easily modified through a pump optical beam. The conductivity of Si pads filled in the gap of CSS is tuned efficiently through the incident pump optical beam with different power, resulting in the modulation of absorption magnitude from 0 to 100% at the fixed operation frequency. Thus, the switch ability of the perfect absorber/reflector can be easily realized. Furthermore, the proposed design is polarization insensitive and operated well at wide incidence angles for both TE and TM waves.     

Dove棱镜的加工误差对耦合损耗的影响

平行光束经过有加工误差的Dove棱镜后,在出射面往往会发生角度倾斜和离轴偏差,从而导致利用Dove棱镜制成的光纤旋转连接器的传输耦合损耗增大。对于Dove棱镜的加工误差在耦合损耗方面的影响,本文利用光线追迹的方法对其进行了理论及模拟分析。分析结果显示,由于加工误差带来的耦合损耗随着Dove棱镜的底角误差及其锥体角误差的增加而增大。而后依据理论结果及光纤旋转连接器的需求,设计加工了5块Dove棱镜,测量了其耦合损耗,并对实验测量值进行了修正,进一步验证了理论的正确性。     

光学相关器系统的固化设计与性能分析

小型固化光学相关器,以偏振分光棱镜和反射型傅里叶透镜作为基本部件,并采用透明固体介质填充光学系统的空隙。该系统通过各元件端面相连,简化了校准难度;使用反射型透镜,具有色像差和轴外像差小的优势。模拟分析表明,这种固化结构具有良好的系统性能,并满足识别的需要。     

Plasmonics for Laser Beam Shaping

This paper reviews our recent work on laser beam shaping using plasmonics. We demonstrated that by integrating properly designed plasmonic structures onto the facet of semiconductor lasers, their divergence angle can be dramatically reduced by more than one orders of magnitude, down to a few degrees. A plasmonic collimator consisting of a slit aperture and an adjacent 1-D grating can collimate laser light in the laser polarization direction; a collimator consisting of a rectangular aperture and a concentric ring grating can reduce the beam divergence both perpendicular and parallel to the laser polarization direction, thus achieving collimation in the plane perpendicular to the laser beam. The devices integrated with plasmonic collimators preserve good room-temperature performance with output power comparable to that of the original unpatterned lasers. A collimator design for one wavelength can be scaled to adapt to other wavelengths ranging from the visible to the far-IR regimes. Plasmonic collimation offers a compact and integrated solution to the problem of laser beam collimation and may have a large impact on applications such as free-space optical communication, pointing, and light detection and ranging. This paper opens up major opportunities in wavefront engineering using plasmonic structures.      

Differential schlieren-interferometry with a simple adjustable Wollaston-like prism

An adjustable Wollaston-like prism is characterized for use in shearing- and differential schlieren-interferometry with laser and white-light illumination. We demonstrate that a polycarbonate prism under mechanical loading behaves identically to Wollaston's classical birefringent beam splitter. A linear relationship is found between the pure bending moment applied to the polycarbonate prism and the resulting light-beam-divergence angle. The utility of this prism in shearing-interferometry is shown by using it in place of the knife-edge in small and large schlieren optical systems. It is inexpensive to fabricate, and it yields adjustable beam-divergence angles over a range of at least 0-24 arc min.     

Foundations for low-loss fiber gradient-index lens pair coupling with the self-imaging mechanism

A fiber-optic collimator that emits a Gaussian beam with its beam waist at a certain distance after the exit face of the lens is labeled a self-imaging collimator. For such a collimator, the waist of the emitted Gaussian beam and its location are partly dependent on the properties of the gradient-index (GRIN) lens. Parameters for the self-imaging collimator are formulated in terms of the parameters of a GRIN lens (e.g., pitch, core refractive index, gradient index, length) and the optical wavelength. Next, by use of the Gaussian beam approximation, a general expression for the coupling power loss between two self-imaging-type single-mode fiber (SMF) collimators is, for the first time to our knowledge, derived as a function of three types of misalignment, namely, separation, lateral offset, and angular tilt misalignment. A coupling experiment between two self-imaging collimators with changing separation distance is successfully performed and matches the proposed self-imaging mechanism coupling loss theory. In addition, using a prism, lateral offset, as well as angular tilt, misalignments are experimentally simulated for a two self-imaging collimator coupling condition by a single collimator reflective test geometry. Experimental results agree well with the proposed loss formulas for self-imaging GRIN lenses. Hence, for the first time to our knowledge, the mathematical foundations are laid for employing self-imaging-type fiber collimators in SMF-based free-space systems allowing optimal design for ultra-low-loss coupling.     

基于光学定心加工的道威棱镜装配方法

本论文针对如何实现道威棱镜光轴与旋转轴平行,将道威棱镜转像理论与光学定心加工结合,提出了基于光学定心加工的道威棱镜组件装配方法.该方法根据道威棱镜旋转轴偏转时其出射光束发生变化的特性确定道威棱镜光轴,并通过车削的方式保证其镜筒外圆旋转轴与其光轴平行.本文具体提出两种道威棱镜组件定轴方案,分别为平行光管定轴方案以及激光定...     

Polarization properties of retroreflecting right-angle prisms

The cumulative retardance Delta(t) introduced between the p and the s orthogonal linear polarizations after two successive total internal reflections (TIRs) inside a right-angle prism at complementary angles phi and 90 degrees - phi is calculated as a function of phi and prism refractive index n. Quarter-wave retardation (QWR) is obtained on retroreflection with minimum angular sensitivity when n=(sqr rt 2+1)(1/2)=1.55377 and phi =45 degrees. A QWR prism made of N-BAK4 Schott glass (n=1.55377 at lambda=1303.5 nm) has good spectral response (<5 degrees retardance error) over the 0.5-2 microm visible and near-IR spectral range. A ZnS-coated right-angle Si prism achieves QWR with an error of < +/- 2.5 degrees in the 9-11 microm (CO(2) laser) IR spectral range. This device functions as a linear-to-circular polarization transformer and can be tuned to exact QWR at any desired wavelength (within a given range) by tilting the prism by a small angle around phi =45 degrees. A PbTe right-angle prism introduces near-half-wave retardation (near-HWR) with a < or =2% error over a broad (4< or =lambda< or =12.5 microm) IR spectral range. This device also has a wide field of view and its interesting polarization properties are discussed. A compact (aspect ratio of 2), in-line, HWR is described that uses a chevron dual Fresnel rhomb with four TIRs at the same angle phi =45 degrees. Finally, a useful algorithm is presented that transforms a three-term Sellmeier dispersion relation of a transparent optical material to an equivalent cubic equation that can be solved for the wavelengths at which the refractive index assumes any desired value.