Journals >Opto-Electronic Engineering
Contents
2013
Volume: 40 Issue 7
16 Article(s)
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Research Article
Effect of Ocular Aberrations on Binocular Summation in Different Light Levels
LIANG Bo, DAI Yun, ZHAO Haoxin, and ZHANG Yudong
A binocular Adaptive Optics (AO) visual simulator was used to study the effect of ocular aberrations on binocular contrast detection in three spatial frequencies (2 c/d, 8 c/d and 16 c/d) and two light levels (1 and 100 cd/m2). For all conditions, AO correction of ocular aberrations improved the binocular/monocular conA binocular Adaptive Optics (AO) visual simulator was used to study the effect of ocular aberrations on binocular contrast detection in three spatial frequencies (2 c/d, 8 c/d and 16 c/d) and two light levels (1 and 100 cd/m2). For all conditions, AO correction of ocular aberrations improved the binocular/monocular contrast sensitivity significantly. For both light levels, the binocular AO benefits in contrast sensitivity showed no significant difference with the benefits achieved monocularly. For signal at 8 c/d and 16 c/d, the visual benefits increased with the increase of light level. For all tested signal at three spatial frequencies, binocular summations were similar for conditions with and without AO correction of ocular aberrations at high light level. For low light level, binocular summation slightly decreased with AO correction. Our findings expand the knowledge on how ocular aberrations affect the binocular contrast detection in different light levels, while also improving the understanding of visual processing..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 7, 1 (2013)
The Model of Zernike Based on Partial Ridge Estimation for Wave-front Aberration Reconstruction of Human Eye
ZENG Ming, SHEN Jianxin, LIANG Chun, and NIU Saisai
In order to improve the wave-front aberration reconstruction accuracy of human eye in adaptive optics system, as well as the accuracy of point spread function, an algorithm of Zernike model based on partial ridge estimation for wave-front aberration reconstruction was proposed. First, based on the Zernike model, the alIn order to improve the wave-front aberration reconstruction accuracy of human eye in adaptive optics system, as well as the accuracy of point spread function, an algorithm of Zernike model based on partial ridge estimation for wave-front aberration reconstruction was proposed. First, based on the Zernike model, the algorithm partial ridge estimation was bought into wave-front aberration reconstruction. Second, in the sense of mean squared errors, the parameter of ridge estimation was ensured to improve the singularity of least square and restrain the enlarger of wave-front measure error. Finally, the error produced by two different kinds of algorithm was discussed with the influence of wave-front slope error. The results show that the partial ridge estimation can decrease the mean squared errors of the modal coefficient effectively. Compared with the singular value decomposition, the mean squared error is reduced by 8%~10%. With the increasing of wave-front measurement error, the accuracy of the partial ridge estimation is much better than the least square estimate, which is useful for studying the image restoration based on wave-front detection in the late of adaptive optics..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 7, 9 (2013)
Multi Scan Mode Atomic Force Microscope with Improved Properties and High Applicability
CHEN Huan, ZHANG Haijun, and ZHANG Dongxian
A multi scan mode Atomic Force Microscope (AFM) with improved properties and high applicability is proposed. The AFM system consists of three different scanners and provides at least three scan modes. The first scanner made of tube piezos and flexure structures uses the sample scan mode to realize high speed and high rA multi scan mode Atomic Force Microscope (AFM) with improved properties and high applicability is proposed. The AFM system consists of three different scanners and provides at least three scan modes. The first scanner made of tube piezos and flexure structures uses the sample scan mode to realize high speed and high resolution imaging for small sized sample. The second scanner made of stack piezos takes the tip scan mode for small and/or large samples. The third scanner driven by step motors provides the sample scan mode to realize wide range imaging for large sized samples. Their scan ranges can reach 4 μm×4 μm, 20 μm×20 μm and 40 μm×40 μm, respectively. Experiments show that, with multi scan modes and special structures, the AFM is of improved properties such as high resolution, quick scan speed, and high repeatability. Meanwhile, it is capable of realizing micro/nano imaging with different scan range for small and/or large sized samples. With these improved properties and high applicability, the AFM can be widely applied in the fields of micro/nano-technology..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 7, 16 (2013)
A Metallic Subwavelength Slit-grooves Structure with Highly Directional Radiation
PENG Ruobing, LI Xiong, ZHAO Zeyu, and LUO Xiangang
A subwavelength structure based on Ag/Al/Ag multilayer, consisting of a narrow slit and periodically patterned metallic grooves, with property of high directional radiation, is proposed and an experimental platform used for direct optical far-field measurement is designed and built. In the simulation, we analyzed the iA subwavelength structure based on Ag/Al/Ag multilayer, consisting of a narrow slit and periodically patterned metallic grooves, with property of high directional radiation, is proposed and an experimental platform used for direct optical far-field measurement is designed and built. In the simulation, we analyzed the influence of beaming effect on structure parameters, and optimized the values by finite element method. The results show that the structure can radiate light with narrow divergence angle in far field by 632.8 nm TM light. Moreover, we performed experiments to test the far-field radiation performances of the slit-grooves sample. The results illustrate that the far-field divergence angle of the structure is about 4.1°, which is in good accordance with simulation results..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 7, 21 (2013)
Design and Experiments of Artificial Compound Eye with Large View Field
SHI Lifang, CAO Axiu, LIU Yan, YE Yutang, DENG Qiling, ZHENG Meiling, and DU Chunlei
A design method for artificial compound eye with large Field of View (FOV) is presented, where the lens array are arranged on curved surface. By researching the FOV characteristic of each lens and studying the FOV relationship between each lens and the whole system, an optimized design method was presented. The design A design method for artificial compound eye with large Field of View (FOV) is presented, where the lens array are arranged on curved surface. By researching the FOV characteristic of each lens and studying the FOV relationship between each lens and the whole system, an optimized design method was presented. The design method of single lens was also described and the arrangement criterion was also given. The imaging structure designed by using the criterion can not only realize the detection with no dead field but also use the least lenses. Experiments were carried out and the imaging performance of the artificial compound eye designed was verified..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 7, 27 (2013)
Design of Gaussian Beam Homogenizer Optical System
LI Yuyao, WANG Fei, and CHE Ying
In order to improve the application level of laser technology, it is necessary to convert a Gaussian beam to a flattop beam. The basic principles and design theory of aspheric Gaussian beam homogenizer was analyzed, and the function of super Gaussian beam was chosen as the mathematical and physical model of flattop beaIn order to improve the application level of laser technology, it is necessary to convert a Gaussian beam to a flattop beam. The basic principles and design theory of aspheric Gaussian beam homogenizer was analyzed, and the function of super Gaussian beam was chosen as the mathematical and physical model of flattop beam. The mapping formula of the incident Gaussian beam and the output flattop beam w established. Then, the surface coefficient of high order even aspheric was given. Moreover, the optical system of Gaussian beam homogenizer was designed with optical design software ZEMAX. The incident beam diameter was 2 mm, the output beam diameter was 4 mm and the wavelength of the laser was 1 064 nm. The energy conversion efficiency was analyzed, and the flattened degree of flattop beam was defined according to the Bessel formula. The design results show that the multiplying power of collimated laser beam expander is 2, the energy conversion efficiency is 95.98% and the flattened degree is 96.6%..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 7, 34 (2013)
Design and Analysis for the High-precision Lens Flexible Structure of Lithography Objective Lens
HUA Yangyang, and GONG Yan
The surface figure precision of lens is decided by the supporting form in lithography objective lens, which influences the performance of optics system further. In order to reach the requirement of lens figure precision, which is better than 5nm RMS, this article introduces a lens supporting structure. The structure inThe surface figure precision of lens is decided by the supporting form in lithography objective lens, which influences the performance of optics system further. In order to reach the requirement of lens figure precision, which is better than 5nm RMS, this article introduces a lens supporting structure. The structure includes three points main flexible supporting and six points aided spring supporting. Optimization and analysis to the structure has been done for considering the influence of gravity, clamping force and thermal on figure precision. The conclusion is that PV of upper surface figure is 21.7 nm, RMS is 4.49 nm, PV of lower surface figure is 81.3 nm and RMS is 3.63 nm. The supporting structure satisfies the requirement of high precision figure in lithography objective lens..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 7, 39 (2013)
Design and Analysis of the Third Mirror Mantle Structure for a Space Camera
FU Lianglianga, HE Xina, WU Jinb, and WANG Zhongshana
The third mirror mantle is a carrier for affixing calefaction patch. First of all, confirm the distance between the third mirror mantle and the third mirror considering thermodynamics. Then, design and optimize the material and structure project of the third mirror mantle. Finally, analyze statics, dynamics and thermalThe third mirror mantle is a carrier for affixing calefaction patch. First of all, confirm the distance between the third mirror mantle and the third mirror considering thermodynamics. Then, design and optimize the material and structure project of the third mirror mantle. Finally, analyze statics, dynamics and thermal characteristics using Finite Element Method (FEM). The result indicates that the project meets the statics and dynamics requirements of design and application, and the project is reasonable and feasible..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 7, 44 (2013)
Design of Natural Refractor’s Optical Structure and Experiment of Measuring Diopters
YAO Cheng, SUI Chenghua, WANG Helin, WEI Gaoyao, and SHI Wenyuan
In order to reduce the impact of eye’s self-control on the diopter measuring, an open-view optical system of natural refractor is established and its optical imaging characteristics and diopter measuring method are investigated. And a method of optometry by measuring the ring thick of the reflection image, rings thick In order to reduce the impact of eye’s self-control on the diopter measuring, an open-view optical system of natural refractor is established and its optical imaging characteristics and diopter measuring method are investigated. And a method of optometry by measuring the ring thick of the reflection image, rings thick method for short, is proposed. Firstly, the optical path of the open windows type natural refractor and its working principle are introduced. Next, the relationship between diopter and far point distance is obtained through theoretical analysis and the ring thick method is proposed to measure the far point distant. Then, build related eye models to verify the optical system’s simulation performance by Zemax. Finally, set up the related optical system to test nine simulation eyes. The experimental results indicate that the relative error of the nine simulation eyes is controlled within 7%. These results satisfy the requirement of diopter measuring very well and the optical system is characterized by compact structure, low cost, good accuracy, and high stability..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 7, 50 (2013)
Design of Reduced Projection Lens for Digital Lithography
LIU Haiyong, ZHOU Jinyun, LEI Liang, LIU Lixia, LIU Zhitao, and GUO Hua
For the reduced-magnification optical projection system in high precision digital lithography, a kind of digital lithography projection lens, composed of six lenses and suitable for 0.7XGA Digital Micro-mirror Device (DMD), is developed and designed. Through optimizing and splicing the three pieces of lens’ structure, For the reduced-magnification optical projection system in high precision digital lithography, a kind of digital lithography projection lens, composed of six lenses and suitable for 0.7XGA Digital Micro-mirror Device (DMD), is developed and designed. Through optimizing and splicing the three pieces of lens’ structure, the objective lens, of which numerical aperture NA=0.1, magnification -0.255 8 and resolution 3.5 μm, is obtained. The results of Zemax software show that it reaches the diffraction limit, which is not affected by DMD grid effect. The optical path difference is less than λ/5 and MTF is more than 0.58 at 145 cycles/mm, which shows that it meets the requirement of the lithography lens’ design. Utilizing Monte Carlo method to analyze the tolerance, 100 groups of lenses’ assembling and fabricating are simulated. The result indicates 90% of the lenses’ FMTF>0.55 when setting the space frequency to 145 cycles/mm, which verifies the practicability of lenses’ assembling and fabricating..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 7, 57 (2013)
The Automatic Spatial Filtering for the Phase Analysis of Spatial Carrier-fringe Pattern
WENG Jiawen, LI Hai, and YANG Chuping
An algorithm for the decision of the automatic filter based on the uniform standard is proposed for the numerical analysis of the spatial carrier-fringe signal. At first, a numerical simulation is presented to demonstrate the feasibility and validity of the proposed algorithm. It is shown that the proper selection of tAn algorithm for the decision of the automatic filter based on the uniform standard is proposed for the numerical analysis of the spatial carrier-fringe signal. At first, a numerical simulation is presented to demonstrate the feasibility and validity of the proposed algorithm. It is shown that the proper selection of the spatial filter would improve the quality of the reconstructed image. However, the distribution of the spectrum varies with different objects. It means that, there is not a deterministic function for the description of the distribution of the spectrum. Therefore, it brings difficulties to define a precise spatial filter. According to the numerical analysis of the distribution of the spectrum of each spatial carrier-fringe signal, the uniform standard for the decision of the threshold of the adaptive filter is researched, which helps the automatic spatial filtering method to be more advantageous for the dynamic and automatic analysis. The detailed steps and an example of 3-D shape measurement are presented..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 7, 63 (2013)
Tightness Testing of Gas Meter Valve
Based on Laser Triangulation
CUI Ting, SHEN Xiaoyan, HU Jiacheng, LI Dongsheng, and LI Jiafu
Valve bonnet and valve seat are the main factors that compose the metering error of gas meter. For evaluating the tightness of gas meter valve in a quantitative way, laser displacement sensor based on triangulation was applied to scan surface profile of the valve working face which was on the two-dimensional air floatiValve bonnet and valve seat are the main factors that compose the metering error of gas meter. For evaluating the tightness of gas meter valve in a quantitative way, laser displacement sensor based on triangulation was applied to scan surface profile of the valve working face which was on the two-dimensional air floating stage. And then, surface roughness parameters were calculated through a Gaussian filter, which could judge the tightness of gas meter valve qualified or not. The results indicate that surface roughness has a big difference between the qualified and unqualified workpiece. Besides, there is a little deviation between the experimental value and the roughmeter measuring value, which has no impact on the testing result. The tightness of gas meter valve can be judged by measuring the valve surface profile, which provides a scientific basis for evaluating the quality of gas meter valve in a quantitative way..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 7, 71 (2013)
The Effect of Pulse Ultraviolet Laser Modification on the Surface Wetting Property of Polycarbonate
WANG Suhuan, LIU Jianguo, Lü Ming, and ZENG Xiaoyan
The effect of the etching and modification power density of 355 nm pulse (100 kHz) ultraviolet (UV) laser on the wetting property of the surface of polycarbonate (PC) materials was found to have the following regularity: when the laser power density was less than 0.27×108 W/cm2, a hydrophilic surface of PC was proThe effect of the etching and modification power density of 355 nm pulse (100 kHz) ultraviolet (UV) laser on the wetting property of the surface of polycarbonate (PC) materials was found to have the following regularity: when the laser power density was less than 0.27×108 W/cm2, a hydrophilic surface of PC was produced; While the laser power density was from 1.15×108 W/cm2 to 10×108 W/cm2, a hydrophobic surface could be obtained. The mechanism of the effect of UV laser etching and modification on the wetting property of PC surface was explored in detail by Scanning Electron Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS). It was shown that, when laser power density was larger than 1.15×108 W/cm2, the polar groups containing element oxygen on the surface of the modified PC increased. However, the porous microstructure with V type-groove resulted from the laser etching and modification determined the hydrophobicity of the PC surface. The distinct microstructure was able to result in the composite contact of water droplet on the PC surface. When certain laser power density was used to modify the PC surface, the feasibility to explain the changes of the water contact angle and wetting property of PC surface with Cassie model was also investigated..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 7, 77 (2013)
A Fast DP Polyline Simplification Algorithm for High-resolution PCB Bare Board Image Contours
HU Tao, REN Xianyi, and ZHANG Jihong
The high-resolution PCB bare board images in online high-precision AOI detection system are up to 60000× 60000 or more. In order to improve processing speed, image contours extraction and DP polyline simplification are used to reduce the amount of processing data. Distance measure of point to segment is one of detThe high-resolution PCB bare board images in online high-precision AOI detection system are up to 60000× 60000 or more. In order to improve processing speed, image contours extraction and DP polyline simplification are used to reduce the amount of processing data. Distance measure of point to segment is one of determinants which affect the efficiency of DP algorithm. A new method to compute distance is proposed. Firstly, a rotating coordinate is established based on the two endpoints of curve, in which the new coordinate value is computed for each point and used to divide the points into three zones and calculate distance, and Manhattan distance is adopted in zone I and III, perpendicular distance in zone II. Compared with Dan Sunday’s method, the proposed method takes full advantage of the computation result of the previous point, and the way to divide the points is more concise and efficient, the distance metric calculation amount for points in zone I and III basically keeps, but the amount for points in zone II which own highest proportion reduces significantly. Experimental results show that the improved distance measure method can improve the efficiency of DP polyline simplification algorithm for high resolution PCB bare board image contours..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 7, 83 (2013)
Temporal High-pass Filtering Nonuniformity Correction with Adaptive Time Constant
CAO Xiaohe, ZHU Bin, GUO Lixin, LI Jing, CHANG Qing, and GONG Tao
The Temporal High-pass Filtering Nonuniformity Correction (THPF-NUC) algorithm has three major drawbacks, namely only correcting the offset coefficient, difficulty in choosing a proper time constant and unclear detail of corrected image. By analyzing the time constant’s effect on the correction quality, an improved THPThe Temporal High-pass Filtering Nonuniformity Correction (THPF-NUC) algorithm has three major drawbacks, namely only correcting the offset coefficient, difficulty in choosing a proper time constant and unclear detail of corrected image. By analyzing the time constant’s effect on the correction quality, an improved THPF-NUC algorithm is proposed. Firstly, to guarantee the uniformity of the gain coefficient, the noise background image is subtracted from the output image of Infrared Focal Plane Arrays (IRFPA) as preprocessing. Then according to the motion degree obtained from the motion detection technique, adaptively adjust the time constant to design the low-pass filter. Lastly the high-boost filtering is adopted to improve the brightness of the whole IR image and enhance the details. The experiment on a real IR video shows that the proposed algorithm eliminates the ghosting artifact and the target fade-out effectively. And the corrected image is high quality with fast convergence rate, giving advantage to real-time engineering application..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 7, 89 (2013)
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