Contents
2015
Volume: 37 Issue 6
17 Article(s)
Export citation format
Research Article
Measurement of diffraction efficiency of dot-matrix-holographic security indentifiers
WU Jingzheng, XU Zhongbao, and ZHOU Shengfei
A measurement method of diffraction efficiency of dot-matrix holography was proposed and an optical system was built. The first order (positive and negative) diffractive beams were separated from the zero and second ones skillfully by placing a plane reflect mirror within the system optical path to make a photodetectorA measurement method of diffraction efficiency of dot-matrix holography was proposed and an optical system was built. The first order (positive and negative) diffractive beams were separated from the zero and second ones skillfully by placing a plane reflect mirror within the system optical path to make a photodetector receive the first order (positive and negative) diffractive beams only. The direction variation of interference fringe cannot affect the experiment value. A half-wave plate was placed behind the laser and the power of the reflected beams and diffractive beams were received by two same photodetectors. At last the diffraction efficiency of eight different holographic security identifiers were calculated..
Optical Instruments
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 471 (2015)
Optical rotation angle detection based on the lock-in amplifier and magneto-optical modulation
CAO Jianghui, JIA Hongzhi, CAO Junjie, YOU Bei, and WANG Liao
According to Faraday effect and lock-in amplification principle, the magneto-optical modulation of polarized light through an optical material occurs after deflection. The output light contains a fundamental signal and a frequency-doubled signal whose frequencies are equal and doubled to modulation frequency respectiveAccording to Faraday effect and lock-in amplification principle, the magneto-optical modulation of polarized light through an optical material occurs after deflection. The output light contains a fundamental signal and a frequency-doubled signal whose frequencies are equal and doubled to modulation frequency respectively. Based on the analyses of amplitudes of fundamental and frequency-doubled signals, we put forward an algorithm for measuring the rotation angle. According to the relation between optical rotation angle and magnetic declination, we put forward a method to calibrate the magnetic declination in the Faraday magneto-optic effect. The feasibility of such measurement approach has been verified by our experiments..
Optical Instruments
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 475 (2015)
Study on measurement technology of the flow field in the flocculation tank
CHENG Yawen, ZHAN Yong, YANG Yake, XIA Rui, ZHANG Yuxiang, and QIAN Xianglin
It is very difficult to measure the full flow field because of narrow gallery and complex hydraulic flow pattern on the corner in the reciprocating baffled flocculation tank. The particle image velocimetry and middle field tests and numerical simulation are used. This paper uses an advanced particle image velocimetry tIt is very difficult to measure the full flow field because of narrow gallery and complex hydraulic flow pattern on the corner in the reciprocating baffled flocculation tank. The particle image velocimetry and middle field tests and numerical simulation are used. This paper uses an advanced particle image velocimetry technology, and develops a two-dimensional numerical model. It can be seen clearly that the improvement of hydraulic conditions of flow field in the different boundary conditions through the flow particle image. By means of the middle field tests, coagulation effect has improved significantly in the improved flocculation, and the addition of tiny eddies can achieve effective flocculation. The comparison shows that the numerical results are in agreement with the experiment results of the flocculation tank..
Optical Instruments
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 479 (2015)
A method for measurement of suspended matter concentration based on laser difference detection
HOU Honglu, CUI Kai, CHEN Haibin, and LIU Kai
A method based on laser difference detection for measuring suspended matter concentration is introduced in the paper. It can be used for the concentration measurement of suspended particles such as smog, dust and other aerosols. Based on the light scattering effect of the suspended particles, real-time monitoring of thA method based on laser difference detection for measuring suspended matter concentration is introduced in the paper. It can be used for the concentration measurement of suspended particles such as smog, dust and other aerosols. Based on the light scattering effect of the suspended particles, real-time monitoring of the suspended particles without changing their properties can be achieved. By means of a direct amplification of the differential signal of the test and reference light, fluctuations of the laser energy can be reduced. The measuring principles and methods are presented in detail. Through the study of the light decaying mechanism during laser propagating in the suspended particles, the relationship between the suspended matter concentration and light intensity attenuation is deduced. We also build a laser differential detection system for the measurement of the suspended matter concentration. By measuring the smog of known concentration, practical feasibility of the measurement method is verified..
Optical Instruments
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 484 (2015)
A study on the test method of the resolution of concave grating
SU Yangqing, HUANG Yuanshen, and YANG Haima
In order to detect the resolution of the concave gratings, it needs to build a precise detection system. Based on the theoretical analysis of the system of the bandwidth of light source, the slit width and the pixel size of the detector, combining with the aberration analysis of concave gratings, a method for the resolIn order to detect the resolution of the concave gratings, it needs to build a precise detection system. Based on the theoretical analysis of the system of the bandwidth of light source, the slit width and the pixel size of the detector, combining with the aberration analysis of concave gratings, a method for the resolution detection system is proposed. According to the standard method in JB/T 8239.2-95 which is named The technical conditions for diffraction grating, the system analyzes the above three factors quantitatively and puts forward a reasonable calculation method. Then it can obtain the practical value of concave grating resolution in the detection system. By experimental verification, the method can distinguish the difference between the test results and the theoretical analysis results from 0.001 0 nm to 0.003 7 nm..
Optical Instruments
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 498 (2015)
Spectrum recovery method of the Fourier transform spectrometer based on fitting algorithm
LI Tao, HUA Jianwen, SUN Xiaojie, and CHEN Ren
In the Fourier transform spectrometer (FTS), obtaining the optical path difference of each sampling points accurately is the key of data processing. The velocity fluctuation of moving mirror will cause equal-time sampling error, and traditional equal optical path difference sampling method can not be used for visible wIn the Fourier transform spectrometer (FTS), obtaining the optical path difference of each sampling points accurately is the key of data processing. The velocity fluctuation of moving mirror will cause equal-time sampling error, and traditional equal optical path difference sampling method can not be used for visible wavelengths. The influence of speed fluctuation is analyzed and a method to calculate the optical path difference of each sampling points based on fitting algorithm is developed. The method is verified by processing the interference signal of visible light with large velocity fluctuation. The experimental results verify its correctness and effectiveness. This method can also be used in any kind of Fourier transform spectrometer..
Optical Instruments
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 504 (2015)
Focusing properties of hyperbolic-cosh-Gaussian beams with optical vortex induced by amplitude
YIN Liang, ZHANG Dawei, and HONG Ruijin
Optical intensity distributions in the focal region play an important role in many optical systems. In this paper, the focal patterns of hyperbolic-cosh-Gaussian (HCG) beam in focal plane were investigated by changing amplitude. It was found that the focal patterns can be altered very considerably by changing the chargOptical intensity distributions in the focal region play an important role in many optical systems. In this paper, the focal patterns of hyperbolic-cosh-Gaussian (HCG) beam in focal plane were investigated by changing amplitude. It was found that the focal patterns can be altered very considerably by changing the charge number of the amplitude,and some novel focal patterns appear, including multiple rhombus and multiple focal spots arry..
Optical Instruments
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 509 (2015)
Resrarch on the stability of the high volume fraction SiC/Al composites frame welded structure applying in the space camera
LIU Xiaofeng, HE Xin, and ZHANG Kai
As for the immaturity of the weld technology applied to the high volume fraction SiC/Al composites, the stability of the space remote sensor skeleton construction was studied. According to the findings of the tolerance analysis of optical deign and structures, the verification of measuring angle and linearity using thrAs for the immaturity of the weld technology applied to the high volume fraction SiC/Al composites, the stability of the space remote sensor skeleton construction was studied. According to the findings of the tolerance analysis of optical deign and structures, the verification of measuring angle and linearity using three-coordinate measuring machine and theodolite was proposed. The feasibility of cementing technology was demonstrated. By the thermal cycling test of frame, the angel and the distance of measuring point were calibrate. The calibrated data was compared. The results show that the torsional angel of the frame is 2.1″ in pitch, 2.3″ in azimuth, and the changes of the distance in the three directions are 0.034 mm, 0.044 mm and 0.034 mm, which can meet the technical requirements of torsional angel smaller than 5″ and the distance tolerance of ±0.05 mm..
Optical Instruments
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 513 (2015)
Design and simulation of TIR combination of lens for a specific rectangular spot based on micro-lens array
LIU Yanjie, HUI Bin, LI Jingzhen, and DING Jinfei
LED is widely used in different lighting environment instead of traditional lighting source as its power becoming higher and higher. LED lens are always needed to make rectangular spot to avoid waste of flux in some illumination design of indoor and road conditions. In this design, total internal reflection(TIR) lens aLED is widely used in different lighting environment instead of traditional lighting source as its power becoming higher and higher. LED lens are always needed to make rectangular spot to avoid waste of flux in some illumination design of indoor and road conditions. In this design, total internal reflection(TIR) lens and micro-lens array are integrated by Light Tools. The transmission and the total reflection surface of TIR lens are all set up to quadric for optimization. And the ratio of length and width of a single micro-lens is set to 1∶1, 3∶2 and 4∶3. The size of the micro-lens and spherical curvature are also variable for further optimization. Finally, a uniform rectangular spot appears on the detector, and the ratio of the length and width is the same as the ratio of micro-lens which can meet illumination design of different condition..
Optical Instruments
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 517 (2015)
Design of a high-precision reference spherical lens for Fizeau interferometer
QU Yi, and SU Dongqi
A high-precision reference spherical lens is designed. The F number of the lens is 0.82. The wavefront PV value is 0.09 λ and RMS value is 0.028 λ. The slope of wavefront is 11 μrad. We calculate the retrace error of the reference spherical lens. The maximum of retrace error is 0.29 nm. A part of surface is measured wiA high-precision reference spherical lens is designed. The F number of the lens is 0.82. The wavefront PV value is 0.09 λ and RMS value is 0.028 λ. The slope of wavefront is 11 μrad. We calculate the retrace error of the reference spherical lens. The maximum of retrace error is 0.29 nm. A part of surface is measured with the reference spherical lens. The results show that precision of 1 nm can be reached..
Optical Instruments
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 522 (2015)
Design of measuring instrument of printing dot based on Blackfin image recognition
WANG Qi, GAO Pengfei, and HU Qi
In the printing industry, printing dot parameters are measured by means of obtaining the values of area, distance,angle of printing dots to control printing quality. Because the traditional measuring instrument in the measuring network area is based on optical measurement and indirect conversion of light into density vIn the printing industry, printing dot parameters are measured by means of obtaining the values of area, distance,angle of printing dots to control printing quality. Because the traditional measuring instrument in the measuring network area is based on optical measurement and indirect conversion of light into density value, there is measurement error and calculation error which affect the printing quality. In this paper, a printing measuring instrument is designed on the basis of digital image processing whose measuring is direct. Its measuring accuracy is higher and it is more helpful for controlling printing quality..
Optical Instruments
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 526 (2015)
Calculation on focusing performance of hard X-ray multilayer Laue lens with 10 keV X-ray
CHENG Lihua, LI Haochuan, and YUE Shuaipeng
The dynamical diffraction theory is employed to analyze the diffraction efficiency and the resolution ratio of hard X-ray waves inside the multilayer Laue lenses. The multilayer Laue lenses are made from NbC/Si with a zone thickness of 40 μm. There are two ways to improve the resolution ratio. The first way is to reducThe dynamical diffraction theory is employed to analyze the diffraction efficiency and the resolution ratio of hard X-ray waves inside the multilayer Laue lenses. The multilayer Laue lenses are made from NbC/Si with a zone thickness of 40 μm. There are two ways to improve the resolution ratio. The first way is to reduce the outmost zone thickness and use wedge structure, but it is hard to form the structure. The second way is to use the high order. This way can improve the resolution ratio without changing the structure. The results show that a focused beam size of 6.72 nm and a mean efficiency of 49.31% can be obtained by the -3rd order of multilayer Laue lens with 10 keV X-ray..
Optical Instruments
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 535 (2015)
Research on the optimized design method of shortening the optical waveguide splitter
FANG Jinhui, CHEN Baoxue, WANG Changjun, and CHEN Ziwei
The paper presents and experimentally verifies a new design method of shortening the optical waveguide splitter.Based on the use of BPM simulation, we summarize the relationship between unit central angle and the curvature radius of the bend loss, establishing the monotone arc connection model about all levels between The paper presents and experimentally verifies a new design method of shortening the optical waveguide splitter.Based on the use of BPM simulation, we summarize the relationship between unit central angle and the curvature radius of the bend loss, establishing the monotone arc connection model about all levels between the Y branch of the optical waveguide splitter. We determine the calculation formula about the optical waveguide splitter length, total bending loss, single bend loss and uniformity. In consideration of the whole length of waveguide, bending loss and uniformity, we introduce the design technique of genetic algorithm for global optimization, designing the reasonable and feasible evaluation function. We choose the initial numerical range of the genetic function, and study the genetic algorithm by using MATLAB. Through the verified design on an 1×8 quartz optical waveguide splitter, we find that insertion loss and uniformity index are equivalent,and the effective length is shorten 3.5 mm or more, compared with the existing similar products..
Optical Instruments
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 541 (2015)
An optical and mechanical system design of an eye-safe laser
YAO Qingxiang, CHEN Baohua, GAO Xueping, and XU Wen
A compact structure for an eye-safe laser, and the transmitting and receiving section of the optical system are designed by Zemax software. It can be easily assembled and mass produced based on a simple structure.The cost of this device is low. The optical system can control the divergence angle of the laser, and meet A compact structure for an eye-safe laser, and the transmitting and receiving section of the optical system are designed by Zemax software. It can be easily assembled and mass produced based on a simple structure.The cost of this device is low. The optical system can control the divergence angle of the laser, and meet the performance requirements..
Optical Instruments
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 547 (2015)
Imaging technology in modern microsystems
ZHANG Xiangxiang
The imaging technology in modern microscope for widefield microscope, confocal microscope and super-resolution microscope is outlined here. The most frequently-used technology in the widefield microscope is brightfield, darkfield, phase contrast, polarization, DIC, modulation contrast and fluorescence. In phase contrasThe imaging technology in modern microscope for widefield microscope, confocal microscope and super-resolution microscope is outlined here. The most frequently-used technology in the widefield microscope is brightfield, darkfield, phase contrast, polarization, DIC, modulation contrast and fluorescence. In phase contrast, there is also apodized phase contrast. In addition, DIC, C-DIC and PlasDIC are also presented. Confocal microscope is developed greatly with the development of computer and manufacture technology. Besides conventional confocal system, the principle of coherent anti-Stokes Raman scattering(CARS) confocal,multi-photo confocal, white confocal are also explained in detail. As for super-resolution microscope, the principle of stimulated emission depletion(STED) and ground state depletion microscopy followed by individual molecule return(GSDIM) are clarified..
Optical Instruments
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 6, 550 (2015)
© Copyright 2018-2021 | Chinese Laser Press. All Rights Reserved 沪ICP备15018463号-20