Journals >Opto-Electronic Engineering
Contents
2013
Volume: 40 Issue 2
24 Article(s)
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Research Article
Analysis of the Simulation Model Based on Remote Sensing Imaging under Vibration
FENG Huajun, DENG Qin, ZHENG Zhenzhen, XU Zhihai, and LI Qi
The mechanism of optical degradation for remote sensing imaging is analyzed under vibration, and the corresponding simulation model is built, which includes imaging module and vibrating module. The imaging module discusses how the plane-array camera and TDI camera work and the imaging module divides the vibration into The mechanism of optical degradation for remote sensing imaging is analyzed under vibration, and the corresponding simulation model is built, which includes imaging module and vibrating module. The imaging module discusses how the plane-array camera and TDI camera work and the imaging module divides the vibration into four categories, including linear one, sinusoidal one, random one, and combined all of above. For the geosynchronous earth orbit satellite, the critical value of vibration is calculated by using the simulation model mentioned above. To verify the reliability of the proposed theoretical analysis, a properly designed semi-physical simulation system has been built. Loading a certain vibration parameter as the vibration source, the system can get a simulated degraded image. Using Modulation Transfer Function (MTF) to measure image quality, the images calculated from the simulation model and obtained by the semi-physical system present a good agreement, which verifies the accuracy and practical applicability of the proposed theoretical analysis..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 2, 1 (2013)
The Staring Imaging Laser Radar Based on Plane Array Detector
YAN Huimin, HU Jian, ZHANG Xiuda, FANG Yi, WANG Pengpeng, and FENG Huajun
In order to quickly obtain the three-dimensional structural information of targets, a staring imaging laser radar system is developed. The system consists of three parts. The first part is that of light emission. The pulsed laser diode stack with center wavelength of 808 nm was used. The second part is the receiver whiIn order to quickly obtain the three-dimensional structural information of targets, a staring imaging laser radar system is developed. The system consists of three parts. The first part is that of light emission. The pulsed laser diode stack with center wavelength of 808 nm was used. The second part is the receiver which is made up of objective lens,image intensifier and CCD camera. The third part is that of image capture and processing. Two images with constant gain modulation and linear gain modulation were obtained in two measurements, and the distance information was demodulated. The error based on noise model was analyzed and estimated for given parameters. Some experiments were made and the results were consistent with theoretical analysis..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 2, 8 (2013)
Field of View Sychronzition Control Method in Laser Active Imaging System
WU Dongsheng, BAI Tingzhu, LIU Bingqi, HU Wengang, and ZHOU Bin
The field of view of Laser irradiation and imaging detection need to be changed in step in laser active imaging system. Two control methods are presented, which are laser waist focus-object adjustment and zooming adjustment forlaser transmitting objective lens. The control formulas are derived from the transformation fThe field of view of Laser irradiation and imaging detection need to be changed in step in laser active imaging system. Two control methods are presented, which are laser waist focus-object adjustment and zooming adjustment forlaser transmitting objective lens. The control formulas are derived from the transformation formula of thin lens for fundamental mode Gaussian beam, which can be applied to method design of field of view sychronzition control. The results of numerical calculation for control formulas show that the control methods are valid. In order to make the adjustment control range and step be satisfied with the real design requirement, the parameters of laser waist focus-object adjustment, laser divergence angel and focal length of laser transmitting objective lens are need to be considered synthetically when designing. The control method of zooming adjustment for laser transmitting objective lens is easier to be carried out than the method of laser waist focus-object adjustment in terms of design difficulty..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 2, 17 (2013)
Maneuvering Target Tracking Based on Class-dependent Tracking Gates
GU Gongsong
In order to solve the problem of maneuvering target tracking in clutter, a joint probabilistic density description of the target state and target class is given. Using the joint state-class probabilistic density, the predicted measurements density function can be proven as a Gaussian mixture distribution. Based on thisIn order to solve the problem of maneuvering target tracking in clutter, a joint probabilistic density description of the target state and target class is given. Using the joint state-class probabilistic density, the predicted measurements density function can be proven as a Gaussian mixture distribution. Based on this attribute, we construct a class-dependent tracking gate for each target class, which achieves more effective association from measurements to tracks. A Gaussian mixture weighted Kalman filter is used in tracking process, where maneuver detection can also be avoided. In simulation, the results with three tracking algorithms are compared, which shows that proposed method here is more effective..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 2, 23 (2013)
Wavefront Phase Recovery from the Plenoptic Camera
ZHANG Rui, YANG Jinsheng, TIAN Yu, and RAO Xuejun
Plenoptic camera could measure the distance and wavefront information simultaneously, but there aren’t any related researches in China. In this paper, we researched plenoptic camera’s wavefront phase recovery ability for a point source. Firstly, the structure between plenoptic camera and other common wavefront sensors Plenoptic camera could measure the distance and wavefront information simultaneously, but there aren’t any related researches in China. In this paper, we researched plenoptic camera’s wavefront phase recovery ability for a point source. Firstly, the structure between plenoptic camera and other common wavefront sensors was compared. Then, imaging principle of plenoptic camera was explained. Finally, farfield spot was simulated by using MATLAB, and wavefront phase was reconstructed with the relevant slope evaluated algorithm. The simulation results show that plenoptic camera has the ability of recovering wavefront phase..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 2, 32 (2013)
Coordinate Measuring Inspection and Inverse Analysis on Ellipsoidal Surface Reflector
Lü Shaobo, WANG Yinhe, ZHANG Yongxi, LIU Xinhua, SUN Zhaoyang, and YIN Xiaojun
Two ellipsoidal surface reflectors, one was made by grinding and the other by molding, were detected using coordinate measuring machine. Contrasting to their profile line, a deviation distribution curve with peaks and valley on the first reflector and a linear deviation distribution on the other one are acquired. TraceTwo ellipsoidal surface reflectors, one was made by grinding and the other by molding, were detected using coordinate measuring machine. Contrasting to their profile line, a deviation distribution curve with peaks and valley on the first reflector and a linear deviation distribution on the other one are acquired. TracePro was used to simulate luminance of their reflecting spot and a reflecting effect ratio of 92% comparing between the two reflectors is obtained. Optical imaging method was used to inspect the reflected light spot and the result shows that bright and dim rings appear alternately in the reflected spot of the grinding reflector, and the other one gets a cloud-like reflected light spot..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 2, 40 (2013)
A Three-dimensional Auto-focusing System Based on Image Processing
WANG Jian, CHEN Hongbin, ZHANG Xiaoming, AN Tao, and XIONG Shuai
In order to solve the deficiency of one-dimensional auto-focusing technology, on the basis of the Six Degrees of Freedom (6-DOF) platform, a three-dimensional auto-focusing system is proposed based on the image processing technology. The system utilizes the CMOS as an image sensor, and the 6-DOF platform as an actuatorIn order to solve the deficiency of one-dimensional auto-focusing technology, on the basis of the Six Degrees of Freedom (6-DOF) platform, a three-dimensional auto-focusing system is proposed based on the image processing technology. The system utilizes the CMOS as an image sensor, and the 6-DOF platform as an actuator, and a computer for obtaining image definition evaluation value and driving 6-DOF platform to realize three-dimensional auto-focusing. The auto-focusing experiments have two parts, which are one-dimensional and three-dimensional auto-focusing closed-loop. According to the coupling relationship of the X-axis, Y-axis and Z-axis, a modified Stochastic Parallel Gradient Descent (SPGD) algorithm is presented. The experimental results show that the closed-loop error is below 3 percent, which meets the precision requirements for three-dimensional auto-focusing..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 2, 46 (2013)
Design of Thickness Measurement Systems for Powder Coating of Lithium-ion Battery Electrode
QIU Baomei, and WANG Jianwen
The coating thickness of lithium-ion battery electrode has the important effect on its electrochemical properties, so the coating thickness should be controlled in industrial production. According to the demand of dynamic, non-contact and high accuracy for lithium-ion battery electrode coating thickness in industrial, The coating thickness of lithium-ion battery electrode has the important effect on its electrochemical properties, so the coating thickness should be controlled in industrial production. According to the demand of dynamic, non-contact and high accuracy for lithium-ion battery electrode coating thickness in industrial, a measurement method based on TwoCCD laser displacement sensor and the ARM+FPGA processor control structure is designed. The μC/OS-II is used to the operation system and two cell immune feedback controllers are presented. The system includes the motor drive units and the signal processing of sensor and so on. Through experimental test, the measurement accuracy of system can reach +/-0.01 mm, which can satisfy the demands in practice..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 2, 52 (2013)
A Theoretical Investigation of Resonant Model on Cantilever Thin Square Plate
JI Ye, JIA Dagong, CHEN Zhitong, ZHANG Hongxia, and ZHANG Yimo
In order to analyze resonant model of the cantilever thin square plate, a theoretical interpretation of resonant vibration based on Rayleigh-Ritz method and amplitude-fluctuation electronic speckle pattern interferometry (AF-ESPI) is proposed. The resonant frequencies and deflection of the first eight orders are obtainIn order to analyze resonant model of the cantilever thin square plate, a theoretical interpretation of resonant vibration based on Rayleigh-Ritz method and amplitude-fluctuation electronic speckle pattern interferometry (AF-ESPI) is proposed. The resonant frequencies and deflection of the first eight orders are obtained. Based on this theory, we calculate the theoretical distribution of the speckled fringe pattern of the square thin cantilever plate. In order to verify the accuracy of theoretical expression and measure in experiment, AF-ESPI is employed to measure resonant frequency and mode shape of this cantilever square plate. The theoretical results are compared with the experimental measurement. Good agreement of vibration fringe patterns is obtained, and the relative errors of resonant frequencies between AF-ESPI and our method are 0.1%~9.1%..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 2, 57 (2013)
Analysis of the Wave-front Diffracted by Three-dimension Pinhole with Shape Errors
XU Jiajun, and XING Tingwen
The interferometer is an indispensable instrument in the modern optic manufacture and testing, whose testing accuracy limits the manufacture accuracy of the optic. In theory, the point diffraction interferometer, which use the wave-front diffracted by a pinhole as reference wave, can be applied in the sub-nanometer optThe interferometer is an indispensable instrument in the modern optic manufacture and testing, whose testing accuracy limits the manufacture accuracy of the optic. In theory, the point diffraction interferometer, which use the wave-front diffracted by a pinhole as reference wave, can be applied in the sub-nanometer optical testing. The deviationbetween the wave-front, which is diffracted by the pinhole with shape errors, and the ideal spherical wave-front is calculated based on finite element method. The main aberrations of the diffracted wave, induced by the shape errors, are also analyzed. When the axes of the pinhole are 380 nm and 320 nm, the deviation is 0.9e-3 λ..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 2, 64 (2013)
Performance Index Analysis of the Support of Lithographic Lens with Multi Flexural Brackets
PENG Haifeng, GONG Yan, and ZHAO Lei
The support of large aperture optical lens is one of the key technologies of the precision optical instrument. The support with multi flexural brackets is widely used in the support of the optical lens because it can eliminate the thermal aberration efficiently and make the lens act with uniform stress. A structure of The support of large aperture optical lens is one of the key technologies of the precision optical instrument. The support with multi flexural brackets is widely used in the support of the optical lens because it can eliminate the thermal aberration efficiently and make the lens act with uniform stress. A structure of a support of optical lens is designed with L-shape multi flexural brackets. A theoretical derivation of its mechanic index is also presented. Take a typical lens as an example, the relationship of the number of brackets and the lens aberration is also given. The results indicate that we can set the distance between the center of the lens and the support point closer and the length of the brackets shorter to to make the aberration of the lens better. At last, the relationship and the geometric indexes of the support is obtained. The results of this article can be the references for the applications of the support with multi brackets..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 2, 71 (2013)
Fast Partially Coherent Imaging Algorithm with Symmetric Illumination Source
SHI Zhaojun, and GAO Yiqing
A fast computation algorithm for aerial images is presented based on the sysmmetric properties of illumination light and matrix multipication. The new discretization approach divides the light source into many concentric circles based on the sysmmetric properties, and the resulting sampled source points can be put alonA fast computation algorithm for aerial images is presented based on the sysmmetric properties of illumination light and matrix multipication. The new discretization approach divides the light source into many concentric circles based on the sysmmetric properties, and the resulting sampled source points can be put along one line outgoing from the origin point, which can reduce the sampling number due to its simplified two dimension traditional orthogonal discretization method to one dimension concentric circles method. In addition, a matrix multiplication technique is adopted to speed up the computation. The simulation results show that under the same sampling number, the circle discretization approach has a higher accuracy than the traditional orthogonal discretization method, and under the same accuracy, the sampling number of concentric circles method is 1/N to the traditional orthogonal discretization method (N×N)..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 2, 76 (2013)
THz Transmission Investigation of Composed Single-layer Metamaterials
XIONG Wei, YAO Jun, LI Wei, and SHEN Jingling
The transmission characters of metal strip arrays were investigated at terahertz range. The experiments and simulations verify that the resonance frequency and bandwidth of metal strip are dependent on the length of the rectangular. We proposed a composed single-layer metamaterials assembled by two metal strips with diThe transmission characters of metal strip arrays were investigated at terahertz range. The experiments and simulations verify that the resonance frequency and bandwidth of metal strip are dependent on the length of the rectangular. We proposed a composed single-layer metamaterials assembled by two metal strips with different length. The transmission spectra exhibit multiple band or a broaden band characters. This single-layer metamaterials have a potential application in THz filter, polarizer, reflector fabricated and provides a new method for the THz designing..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 2, 81 (2013)
Impact of Non-ideal Illumination Pupil on Imaging Performance of Lithography
CHEN An, LIN Wumei, and JIANG Haibo
The impact of Non-ideal illumination pupil on imaging performance of lithography is calculated using software PROLITH. Effect of the sensitivity of image CD placement error caused by a shift of illumination with numerical aperture (NA) and coherent factor (σ) is also calculated. Calculations show that the main effect oThe impact of Non-ideal illumination pupil on imaging performance of lithography is calculated using software PROLITH. Effect of the sensitivity of image CD placement error caused by a shift of illumination with numerical aperture (NA) and coherent factor (σ) is also calculated. Calculations show that the main effect of a shift of illumination on imaging performance of lithography is the image CD placement error in the ideal optical systems. The image CD placement error caused by a shift of illumination is proportional to the defocus, and the slope of line increases with increasing the shift of illumination. A shift of illumination has little effect on H-V bias and Depth of Focus (DOF). The impact of a shift of illumination and pupil filling unbalance on image CD placement error is the sum of the CD placement error induced separately..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 2, 87 (2013)
Research of Vacuum Micro-pressure Controlling Based on PSS Etching Platform
LIN Yongben, LI Yongtao, LI Chaobo, XIA Yang, WANG Minggang, and CHEN Yan
A mathematic algorithm based on the adaptive fuzzy PID was introduced to monitor and regulate the nonlinear micro-pressure feature of inductively coupled plasma (ICP) vacuum chamber in the process of current patterned dry-etching of sapphire substrate. This algorithm realizes the regulation of micro-pressure of chamberA mathematic algorithm based on the adaptive fuzzy PID was introduced to monitor and regulate the nonlinear micro-pressure feature of inductively coupled plasma (ICP) vacuum chamber in the process of current patterned dry-etching of sapphire substrate. This algorithm realizes the regulation of micro-pressure of chamber in the vacuum condition flexibly through adjusting variables of the Mass Quality Flowmeter (MFC) and compression release valve connected with vacuum pump. The results of Matlab simulation and test on the dry-etching chamber substantiate the efficacy of this algorithm. In the vacuum condition ranged from 0.13 Pa to 20 Pa, the algorithm features strong robustness, small overshoot, short transition time, and etc. which can meet the dry-etching specification of standard etching rate, etching ration selectively and etching uniformity..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 2, 93 (2013)
Novel Projection Lens Design for Large-area PCB Lithography
DENG Yafei, ZHOU Jinyun, LEI Liang, RAN Zuo, and ZHOU Yamei
For large-area and high-density Printed Circuit Board (PCB) lithography, we use ZEMAX optical design software to design a kind of lithographic projection lens with 8 optics element． Symmetrical double Gaussian structure is applied in the lens, the magnification is -1, and numerical aperture NA = 0.06. It can exposure aFor large-area and high-density Printed Circuit Board (PCB) lithography, we use ZEMAX optical design software to design a kind of lithographic projection lens with 8 optics element． Symmetrical double Gaussian structure is applied in the lens, the magnification is -1, and numerical aperture NA = 0.06. It can exposure a area of Φ = 80 mm at a time, and have better than 7 μm resolution and 120 μm focus shift．The result of tolerance analysis show that the tightest tolerance is part of the element tilts, which should be lower than 0.017 °. We use the Monte Carlo method to simulate fabricating and assembling 50 group of lens. The results show 90% of the lens MTF > 0.58 at spatial frequency 72 line/mm, which can ensure more than 90% yield when they are fabricated and assembled..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 2, 100 (2013)
Finite Element Analysis for Optical Property of Infrared Lead
YANG Jinsong
Optical property of infrared lead was solved by finite element analysis to make sure that the deformation of optical system under dynamic environment meets imaging requirement. The optic property of infrared lead was analyzed by means of finite element model based on model updating. First, composite material element waOptical property of infrared lead was solved by finite element analysis to make sure that the deformation of optical system under dynamic environment meets imaging requirement. The optic property of infrared lead was analyzed by means of finite element model based on model updating. First, composite material element was created to simulate the connection relation between parts, and then property parameter of composite material element was modified repeatedly to make the result of tested model and calculated model identical. Therefore, correct and effective model finite element was achieved. Finally, the simulation calculation of transient vibration and overload was carried out for the updated finite element model of Infrared lead. Analysis result indicate: mirror face deflection of structure under dynamic environment less than 3″, and mirror face deformation of structure under dynamic environment less than 1 μm. The mirror face deformation and deflection of infrared lead optical system under dynamic environment were within the allowable range, and the optical property of infrared lead meets the imaging requirement..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 2, 105 (2013)
Infrared Image Magnification Algorithm Based on Linear Interpolation and Sine Gray Level Transformation
GONG Changlai, LUO Cong, YANG Dongtao, and HUANG Jiexian
Organically combined linear interpolation and sine gray level transformation, a new infrared image interpolation and zooming method has been proposed. Firstly, bilinear interpolation method is adopted to calculate the interpolation points as the preliminary interpolation. And then S-shaped sine gray transformation curvOrganically combined linear interpolation and sine gray level transformation, a new infrared image interpolation and zooming method has been proposed. Firstly, bilinear interpolation method is adopted to calculate the interpolation points as the preliminary interpolation. And then S-shaped sine gray transformation curve is used to enhance processing as the final interpolation. The method makes full use of the simple algorithm and small computational amount of the linear interpolation, meanwhile reduces the effect of image edge blurring brought by linear interpolation. Experimental results show that method of interpolation is better than traditional bilinear interpolation..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 2, 110 (2013)
Theoretical Calculation on Infrared Radiation of Air Target Scarfskin
FENG Yunsong, Lü Xiangyin, LING Yongshun, and ZHOU Rui
The infrared characteristics of an air target’s scarfskin are very important for the detection and identification of the air target. Referring to a certain oversea air target, its flight path was set. Aerodynamic heating and radiation from environment being considered comprehensively, one dimensional heat conduction eqThe infrared characteristics of an air target’s scarfskin are very important for the detection and identification of the air target. Referring to a certain oversea air target, its flight path was set. Aerodynamic heating and radiation from environment being considered comprehensively, one dimensional heat conduction equations were established about the air target’s scarfskins. These equations were solved with backward difference approximation, and then temperature distributions of the scarfskins were achieved in 4:00 AM~4:45 AM and 12:00 PM~12:45 PM. Finally, influence of environment radiation being considered, while time and space changing, the infrared radiant intensity distributions of the scarfskins were calculated numerically in 3～5 μm and 8～14 μm. The result shows that far infrared radiant intensity of the scarfskins is far more than their middle infrared radiant intensity and the infrared characteristics have few changes when the air target flights..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 2, 115 (2013)
Non-uniformity Correction of IRFPA Based on the Radiation Attenuation
LI Manliang, WU Qinzhang, and CAO Xiaowei
For a motorized infrared measurement system single-point non-uniformity correction results are poor and two-point non-uniformity correction is restricted by many factors, a new non-uniformity correction method is put forward based on radiation attenuation. The method uses different attenuator to produce Infrared Focal For a motorized infrared measurement system single-point non-uniformity correction results are poor and two-point non-uniformity correction is restricted by many factors, a new non-uniformity correction method is put forward based on radiation attenuation. The method uses different attenuator to produce Infrared Focal Plane Array (IRFPA) response to achieve the two-point correction and the segmented two-point correction. The segmented two-point correction by the establishment of the decay rate and the IRFPA gray response curve can calculate any radiation response, and then the two-point correction finishes in the segment without prior measurement calibration source radiation. The experimental results show that the method is superior to conventional correction methods, and improves the uniformity about 50% under low radiation background. At the same time, the new correction methods have many advantages, such as environmental adaptability and simple operation..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 2, 123 (2013)
Adaptive Zero Calibration for the Designed Thermal Microscope Imaging System
GAO Meijing, GU Haihua, GUAN Congrong, and WU Weilong
In order to accurately calibrate micro scanning position and improve the spatial resolution of micro thermal imaging systems, the zero of micro scanning should be determined. The image registration algorithm was used to calculate the micro-displacement, and then a new adaptive zero calibration was presented based on geIn order to accurately calibrate micro scanning position and improve the spatial resolution of micro thermal imaging systems, the zero of micro scanning should be determined. The image registration algorithm was used to calculate the micro-displacement, and then a new adaptive zero calibration was presented based on geometric principle. Using telescopic thermal image to simulate the real system, different reconstruction methods were adopted to construct the simulation image and the real thermal microscope image before and after adaptive zero calibration. The results show that the method significantly improves the oversample reconstructed image quality, and increases the system spatial resolution. This method can also be used in other electro-optical imaging systems..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 2, 130 (2013)
An Improved RWA Algorithm and Wavelength Converter Allocation Strategy in Intelligent Optical Networks
[in Chinese], and [in Chinese]
Routing and Wavelength Assignment (RWA) is one of the key issues in Intelligent Optical Network (ION). Dueto the Wavelength Continuity Constraint (WCC), RWA algorithms need to introduce the wavelength converter to solve the wavelength conflict. An optical network dynamic RWA algorithm based on improved ant colony optimRouting and Wavelength Assignment (RWA) is one of the key issues in Intelligent Optical Network (ION). Dueto the Wavelength Continuity Constraint (WCC), RWA algorithms need to introduce the wavelength converter to solve the wavelength conflict. An optical network dynamic RWA algorithm based on improved ant colony optimization is proposed. The link idle ratio was introduced into the traditional ant transition probability as a constraint and a novel wavelength converter allocation strategy was discussed. Compared the blocking probability and resources utilization through the regular MESH and NSFNET network with numerical simulation, the result shows that in the case of the same traffic intensity, the blocking probability and channel utilization performance of the improved algorithm are improved significantly, compared with Dijkstra + First-Fit algorithm with wavelength convertors..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 2, 137 (2013)
Analysis and Improvement of CDMA Optical Module Intermodulation Distortion Characteristics
HU Xinyan, LIU Jinmei, LI Aitao, and HUO Wenxiao
Nonlinear distortion of CDMA optical module has severely affected the whole system performance in a communication system, for the problem, by the use of IP3(the third-order Intercept point) and IM3(third-order intermodulation signal) parameters as an index of measuring CDMA optical module nonlinear distortion, and distNonlinear distortion of CDMA optical module has severely affected the whole system performance in a communication system, for the problem, by the use of IP3(the third-order Intercept point) and IM3(third-order intermodulation signal) parameters as an index of measuring CDMA optical module nonlinear distortion, and distortion properties of optical modules is analyzed in detail from two aspects including lasers and amplifiers. On this basis, basic methods to improve the CDMA module distortion are discussed preliminarily, such a series of methods as changes to module internal laser bias currents, amplifier bias currents and peripheral matching circuits, and etc. The experimental results demonstrate that the proposed method is effective, which can improve the system distortion index in a certain degree, by watching influence on IP3 and IM3 parameters when condition changes. At present, the research for such distortion characteristics generally concentrated on the electrics, less on the optical devices combined with electrical devices at home and abroad. The method has certain significance and value for actual commercial optical module products..
Opto-Electronic Engineering
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 2, 145 (2013)
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