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Wideband film polarizer design

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Chinese Optics Letters 2008年第7期6卷 544-546页

作者：傅小勇易葵邵建达范正修 Shanghai Institute of Optics and Fine Mechanics Chinese Academy of SciencesShanghai 201800 2 Graduate University of Chinese Academy of SciencesBeijing 100049 Shanghai Institute of Optics and Fine Mechanics Chinese Academy of SciencesShanghai 201800

The reflection and transmittance of s- and p-polarized lights should be treated separately at nonzero angle incidence. By choosing two special film materials whose refractive indices meet the Brewster condition in a given incident angle, the reflection of p-polarized light can be eliminated. When the two materials are fabricated into multilayer stacks, the reflection of s-polarized light can be largely increased while the reflection of p-polarized light keeps low. According to this principle, a film polarizer with bandwidth of 198 nm or even more is designed.

关键词： Angle measurement Light polarization optical instruments optical properties Polarization Reflection Refractive index

Evanescent waves of an annular left-handed material lens

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Chinese Optics Letters 2009年第2期7卷 134-137页

作者：闫长春崔一平王琼吕昌贵 Advanced Photonics Center School of Electronic Science and Engineering Southeast University School of Physics and Electronic Engineering Xuzhou Normal University

The imaging system formed by an annular left-handed material （LHM） lens as well as the evanescent waves in the lens are simulated numerically with a finite-difference time-domain （FDTD） method. For b - a 〉 λ （a and b are respectively the inner and outer radii of the annular lens, and λ is the wavelength）, when a point source is placed at an internal grid point, we demonstrate that the evanescent waves are produced around the internal interface, and cannot propagate outwards. As for b - a 〈λ ）,, the evanescent waves appear around both the internal and the external interfaces, which remarkably implies the coupling between the two interfaces. Hence it can be inferred that the evanescent waves around the external interface participating in the super-resolution imaging result from the coupling of the evanescent waves around the interface. Moreover, the partly uncomprehended properties of the evanescent waves in the LHM slab are also disclosed. It is conducive to understanding the evanescent waves in the LHMs further.

关键词： Finite difference time domain method Lenses Metamaterials Method of moments optical instruments Optoelectronic devices

Coarse error analysis and correction of a two-dimensional triangulation range finder

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Chinese Optics Letters 2006年第2期4卷 84-86页

作者：桂华侨吕亮黄伟徐军何德勇王焕钦谢建平赵天鹏明海 Department of Physics

A real-time two-dimensional （2D） triangulation range finder is presented, which is composed of two linear complementary metal oxidation semiconductor （CMOS） chips, two camera lenses, and four light emitting diodes （LEDs）. The high order distortion in image aberrations is the main factor responsible for the coarse errors. The theoretical prediction is in good agreement with experiments and the correction equation is used to obtain more reliable results with the unique distortion coefficient in tile whole working region.

关键词： Camera lenses Distortion (waves) Error analysis Image processing Light emitting diodes Microprocessor chips MOS devices optical instruments Real time systems Triangulation Two dimensional

Study on eight-pass dual-frequency laser interferometer with nanometer precision

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Chinese Optics Letters 2005年第9期3卷 513-515页

作者：高海军程兆谷宁志高崔品静黄惠杰 Precise Optoelectronic Measure and Control R&D Center Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai 201800

A new dual-frequency laser displacement measurement interferometer with nanometer precision has been developed. An eight-pass optical subdivision technology is proposed to improve resolution based on commercial interferometers. A static positioning error measuring method has been used to examine the precision and repeatability of the laser interferometer. An optical resolution of 1.24 nm and an accuracy of nanometer scale have been achieved.

关键词： Information technology Measurement errors Measurement theory optical instruments

Estimation of measuring uncertainty for optical micro-coordinate measuring machine

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Chinese Optics Letters 2004年第12期2卷 704-707页

作者：宋康蒋庄德 Institute of Precision Engineering Xi'an Jiaotong University Xi'an 710049 State Key Lab of Mechanical Manufacturing System Xi'an Jiaotong University Xi'an 710049

Based on the evaluation principle of the measuring uncertainty of the traditional coordinate measuring machine (CMM), the analysis and evaluation of the measuring uncertainty for optical micro-CMM have been made. optical micro-CMM is an integrated measuring system with optical, mechanical, and electronic components, which may influence the measuring uncertainty of the optical micro-CMM. If the influence of laser speckle is taken into account, its longitudinal measuring uncertainty is 2.0 μm, otherwise it is 0.88 μm. It is proved that the estimation of the synthetic uncertainty for optical micro-CMM is correct and reliable by measuring the standard reference materials and simulating the influence of the diameter of laser beam. With Heisenberg's uncertainty principle and quantum mechanics theory, a method for improving the measuring accuracy of optical micro-CMM through adding a diaphragm in the receiving terminal of the light path was proposed, and the measuring results are verified by experiments.

关键词： Coordinate measuring machines Diaphragms Laser beams Measurement theory Measurements optical instruments Speckle

Compact liquid-refractive index measuring equipment

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Chinese Optics Letters 2003年第5期1卷 278-280页

作者：叶红安王熙常存 Department of Electronic Engineering Heilongiang UniversityHarbin 150080 Heilongjiang August-First Land Reclamation University Harbin 158308 Department of Electronic Engineering Heilongjiang UniversityHarbin 150080

Based on total reflection principle, a compact liquid-refractive index measuring equipment was designed and fabricated, in which a diode laser was used as light source and a charge-coupled device (CCD) as photodetector. The influence on measurement accuracy of the wavelength shift and intensity fluctuation of the diode laser were surmounted by an effective feedback method. It is crucial whether the diode laser could be used in such a system.

关键词： Charge coupled devices Liquids optical instruments optical variables measurement Photodetectors

Dual-core photonic crystal fiber polarization splitter based on lead silicate glass

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Optoelectronics Letters 2015年第3期11卷 170-173页

作者：孙宇伟白育堃马秀荣 Key Laboratory of Film Electronics and Communication Devices Tianjin University of Technology

A dual-core photonic crystal fiber(PCF)polarization splitter based on lead silicate glass is *** characteristics of the polarization splitter are analyzed using full-vector finite element *** with the silica glass PCF polarization splitter with the same structure,it is shown that the new material polarizer can realize splitting with less coupling loss and higher extinction *** the wavelength is 1 550 nm and the PCF length in the beam splitter is 688μm,the coupling loss is only 0.001 9 d B,and the extinction ratio for the input core is-64.1 d B.

关键词： Crystal whiskers Finite element method Glass Light extinction Nonlinear optics optical instruments Photonic crystals Polarization Silicates

Design of a fiber polarizer based on an asymmetric dual-core photonic crystal fiber

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Optoelectronics Letters 2011年第4期7卷 253-255页

作者：孙兵陈明阳于荣金张永康周骏 Department of optical Engineering School of Mechanical EngineeringJiangsu University School of Information Science and Engineering Yanshan University Faculty of Science Ningbo University

We propose a novel optical polarizer based on an asymmetric dual-core photonic crystal fiber(PCF) with triangular lattice *** fiber is designed as that the effective indices of modes in the two cores are matched at one polarized state but mismatched at another polarized *** a result,one of the polarization states is coupled to the other core and transferred into a high-order *** transmission properties of the polarizer are investigated by the semi-vectorial beam propagation method(SV-BPM).Numerical results demonstrate that a device length of 11.3 mm shows extinction ratio as low as-20 dB with bandwidth as great as 80 nm ranging from 1.51 mm to 1.59 mm.

关键词： Beam propagation method Crystal whiskers Fibers Nonlinear optics optical fiber fabrication optical instruments Photonic crystals

Symmetrical fully-etched and chirped beam splitter based on a subwavelength binary blazed grating

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Optoelectronics Letters 2012年第3期8卷 182-185页

作者：周唯张华良杨俊波杨俊才 College of Science National University of Defense Technology

A novel symmetrical chirped beam splitter based on a binary blazed grating is proposed, which adopts the fully-etched grating structure compatible with the current fabrication facilities for CMOS technology and convenient for integration and manufacture process. This structure can realize nearly equal-power splitting operation under the condition of TE polarization incidence. When the absolutely normal incidence occurs at the wavelength of 1580 nm, the coupling efficiencies of the left and the right branches are 43.627% and 43.753%, respectively. Moreover, this structure has the tolerances of 20 nm in etched depth and 3?in incident angle, which is rather convenient to manufacture facility.

关键词： CMOS integrated circuits optical instruments Prisms