Journals >Opto-Electronic Engineering
Contents
2008
Volume: 35 Issue 11
28 Article(s)
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Research Article
Once Imaging Catadioptric Step Zoom Lens
SHI Guang-hui
A catadioptric step zoom lens for remote supervision TV is designed. Once imaging catadioptric step zoom is proposed so that three bands such as weak light,white light and near infrared share the same optical system. Theory is explained in detail and design examples are displayed in the paper. The disadvantages that thA catadioptric step zoom lens for remote supervision TV is designed. Once imaging catadioptric step zoom is proposed so that three bands such as weak light,white light and near infrared share the same optical system. Theory is explained in detail and design examples are displayed in the paper. The disadvantages that the secondary spectrum of reimaging catadioptric step zoom lens can not be corrected are overcome. Moreover,the black spots generated in image plane center are avoided and the structure is simple..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 35, Issue 11, 1 (2008)
Multi-position North Seeker and Error Analysis of Position Transformation Based on Dynamically Tuned Gyro
XIE Mu-jun, TAN Xu-guang, and WANG Zhi-qian
In order to reduce the influence of position error in every standstill-position of turntable on north-seeking precision,the work process of the Dynamically Tuned Gyro (DTG) multi-position north seeker and the principle of the azimuth arithmetic are introduced,and the relation between position error and north-seeking prIn order to reduce the influence of position error in every standstill-position of turntable on north-seeking precision,the work process of the Dynamically Tuned Gyro (DTG) multi-position north seeker and the principle of the azimuth arithmetic are introduced,and the relation between position error and north-seeking precision is analyzed. The mathematical model between position error and north seeking error is gotten through error theory and partial derivative principle. The analyses of theory and results of experiment show that,in the condition of the same north-seeking points,the less position error is,the higher north-seeking precision is; in the condition of the same position error,the more north-seeking points are,the higher north-seeking precision is. According to the theoretical analyses,two error compensation methods are presented..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 35, Issue 11, 4 (2008)
Method of High Accuracy Control for Motor-based Optoelectronic Tracking Equipment and Simulation
NING Da-yong, and GAO Yun-guo
A mathematic method for ensuring that motor-based optoelectronic tracking equipment works high accurately was introduced. The two-axis inclinometer was settled on the base,and the inclinometer examined the planeness of base in real time. According to the data of two-axis inclinometer,the optoelectronic tracking equipmeA mathematic method for ensuring that motor-based optoelectronic tracking equipment works high accurately was introduced. The two-axis inclinometer was settled on the base,and the inclinometer examined the planeness of base in real time. According to the data of two-axis inclinometer,the optoelectronic tracking equipment should change the angle of horizontal axis and vertical axis. The mathematic model was established and the working principle was analyzed. Then,the formulas of horizontal axis’ transfer and vertical axis’ transfer were worked out. The CAD model was built and simulated with virtual prototype technology. Analysis and simulation prove that the mathematic method could keep tracking precision of motor-based optoelectronic tracking equipment..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 35, Issue 11, 8 (2008)
Multi-cue Fusing Tracking Algorithm Based on Particle Filter
TAO Jie, and BI Du-yan
To solve the problem that target tracking only based on color cue always fails under complex background,a multi-cue fusing tracking algorithm is presented based on particle filter. Histogram of color is global description to targets,while histogram of oriented gradients contains some construction information. So they cTo solve the problem that target tracking only based on color cue always fails under complex background,a multi-cue fusing tracking algorithm is presented based on particle filter. Histogram of color is global description to targets,while histogram of oriented gradients contains some construction information. So they can complement each other,and target is represented by both histogram of color and histogram of oriented gradients in our algorithm. Color and gradient information are fused and updated online under the frame of particle filter. Experiments show that the proposed method provides more reliable result and robustness..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 35, Issue 11, 13 (2008)
Detection of Infrared Small Dim Targets Based on Layered Dynamic Programming
LONG Yun-li, XU Hui, AN Wei, and SHENG Wei-dong
In order to detect infrared dim targets in low Signal-to-noise Ratio (SNR) background,an adaptive Track-before-detect (TBD) algorithm based on Directional Median Value Filtering (DMVF) and Layered Dynamic Programming (LDP) was proposed. The structure clutter was suppressed using four adaptive Weighted Directional MediaIn order to detect infrared dim targets in low Signal-to-noise Ratio (SNR) background,an adaptive Track-before-detect (TBD) algorithm based on Directional Median Value Filtering (DMVF) and Layered Dynamic Programming (LDP) was proposed. The structure clutter was suppressed using four adaptive Weighted Directional Median Values (WDMV) on the ground of its correlation in the local neighbor. For the out-threshold potential targets,the LDP was implemented for multiframe detection through the continuity and smooth of the trajectories in order to reduce the computation complexity. As to the matching the trajectories detected in every layer,a decision was made. The simulated experiments show that the SNR is effectively improved by DMVF,and LDP reduces the false detection probability and greatly improves the operation speed..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 35, Issue 11, 18 (2008)
Method for Designing Grating Beam Splitter with Plane-surface-relief
CHEN Min, YU Sheng-lin, JIANG Hai-hui, LUO Ning-ning, and GAO Yi-qing
A method is proposed for designing the grating splitter with plane-surface-relief. Ray tracing theory is used to obtain phase and universal polynomial function of grating,and the coefficient of the polynomial function is optimized by genetic algorithm. Several grating splitters with ratio 1:2×2,1:3×3,1:4×A method is proposed for designing the grating splitter with plane-surface-relief. Ray tracing theory is used to obtain phase and universal polynomial function of grating,and the coefficient of the polynomial function is optimized by genetic algorithm. Several grating splitters with ratio 1:2×2,1:3×3,1:4×4 and diffraction efficiency 81.83%,81.11% and 74.01%respectively are designed based on the method. The simulation made by Matlab software shows that the intensity uniformities of the three gratings designed through the method achieve 0.023 94,0.183 8 and 0.191 2 respectively,which indicates that the method has universal compatibility for designing the diffraction optics components..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 35, Issue 11, 24 (2008)
Simulation and Fabrication of 5Gb/s Monolithically Integrated Optical Receiver Front End
FAN Chao, CHEN Tang-sheng, CHEN Chen, JIAO Shi-long... and YE Yu-tang|Show fewer author(s)
A 850nm monolithically integrated optical receiver front end,which consisted of a PIN photodiode and a Transimpedance Amplifier (TIA),was designed and fabricated in a 0.5μm gate-length GaAs PHEMT standard process. A photodiode model was established based on published literature and SILVACO software. The results of expeA 850nm monolithically integrated optical receiver front end,which consisted of a PIN photodiode and a Transimpedance Amplifier (TIA),was designed and fabricated in a 0.5μm gate-length GaAs PHEMT standard process. A photodiode model was established based on published literature and SILVACO software. The results of experiment show that the matching between model and data of test is good. The eye diagrams of optical receiver are measured at bit rate up to 5 Gb/s. The photodiode has a diameter of 50 μm,a capacitance of 0.51 pF and a maximum dark current of 30 nA. The TIA achieves a -3 dB bandwidth of nearly 10 GHz,a transimpedance gain of 43 dBΩ and minimal equivalent input noise current density of 17.6 pA/Hz1/2..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 35, Issue 11, 29 (2008)
Fast Skew Correction for Microarray Image Based on Cellular Neural Networks
LV Rui-min, WANG Shu-rong, LUO Zheng-quan, TANG Xiao-ping, and YAN Wei
Skew correction algorithm is indispensable in fully automated microarray image processing. Since most previous image skew correction algorithms for microarray were time-consuming,a fast skew correction algorithm was proposed based on Cellular Neural Networks(CNN). The first step was to obtain the center points of all sSkew correction algorithm is indispensable in fully automated microarray image processing. Since most previous image skew correction algorithms for microarray were time-consuming,a fast skew correction algorithm was proposed based on Cellular Neural Networks(CNN). The first step was to obtain the center points of all spots by applying a series of CNN templates. The second step was to find out the skew angle by performing Hough transform and calculating deviation. The final step was to correct skew by CNN grey-scale image rotation template. Our algorithm utilized the parallel processing attributes of CNN and the characteristics of microarray image. Experiment results and theoretical analysis show that the algorithm works accurately and fast..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 35, Issue 11, 33 (2008)
Recent Development of the Seawater Salinity Measurement Technology
ZHAO Yong, HU Kai-bo, CHEN Shi-zhe, and LIU Chang-wei
Traditional method for seawater salinity measurement and electroconductivity measurement technology is introduced in this article. The merits,disadvantages,and measurement characteristics of the method are introduced. Recent developments in this field are discussed in detail,including microwave remote sensing,bare fibeTraditional method for seawater salinity measurement and electroconductivity measurement technology is introduced in this article. The merits,disadvantages,and measurement characteristics of the method are introduced. Recent developments in this field are discussed in detail,including microwave remote sensing,bare fiber sensor,surface plasmon resonance,position sensitive detector and optical technology,and salinity-sensitive material. Theory and current situation of these technologies are thoroughly analyzed. The advantage and disadvantage of each kind of salinity measurement technology are compared. In the end,some existed key problems which need to be solved in the future are proposed..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 35, Issue 11, 38 (2008)
Effect and Simulation of the Deviant Angle Error on TDI CCD Cameras Image
YANG Xiu-bin, HE Xiao-jun, ZHANG Liu, XU Kai, and JIN Guang
The process of deviant angle adjustment and the factors of deviant angle matching error were analyzed. Then,the mathematical model for corresponding relation between scanning camera pixels and the point of scenery was established. According to cumulative TDI CCD imaging exceeding the corresponding pixel horizontal and The process of deviant angle adjustment and the factors of deviant angle matching error were analyzed. Then,the mathematical model for corresponding relation between scanning camera pixels and the point of scenery was established. According to cumulative TDI CCD imaging exceeding the corresponding pixel horizontal and vertical offset,camera imaging was simulated when stability of satellite attitude changed. At the same time,the uniaxial flotation turntable and plane array CCD were used to imaging experiment. The experiment imaging speed should match simulation imaging speed and the offset of plane array CCD imaging was cumulated to simulate CCD push-broom image. At last,we used image contrast and cross-correlation similar measure simulation to analyze experimental imaging quality. Simulation and experimental imaging are just difference only 0.03 in the imaging contrast and cross-correlation similar measure,which can meet the needs of experiments. The model can be further used for image simulation for testing satellite camera on the ground..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 35, Issue 11, 45 (2008)
Spectral Irradiance Responsivity Calibration of Space Ultraviolet Remote Sensing Instrument by Diverging Light Illuminating Method
ZHANG Zhen-duo, WANG Shu-rong, LI Fu-tian, LI Bo... and YUAN Jia-guang|Show fewer author(s)
On the basis of radiation theory,the result expressions of spectral irradiance responsivity calibration of space ultraviolet remote sensing instruments are deduced by diverging light illumination method and parallel light illumination method. The factors which impact the calibration results of two methods are analyzed.On the basis of radiation theory,the result expressions of spectral irradiance responsivity calibration of space ultraviolet remote sensing instruments are deduced by diverging light illumination method and parallel light illumination method. The factors which impact the calibration results of two methods are analyzed. The calibration method error of diverging light illumination method is calculated through the relevant testing. The calculation results show that the calibration method error of diverging light illumination method is 0.5～1.2% in the assumed condition that parallel light irradiance is uniform and the diverging light source is the Lambert source. The calculation result has some guidable significance for carrying on spectral irradiance responsivity calibration of space ultraviolet remote sensing instrument by diverging light illuminating method..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 35, Issue 11, 51 (2008)
Methods of Improving CCD Alignment Measurement Accuracy in Wild Environment
DONG Ming-guo, GUO Xiao-song, ZHOU Zhao-fa, MA Fu-lu, and SHI Yin-jie
Aimed at the weak anti-interference ability of traditional angle measuring system in the open field,a set of complete plan was proposed to enhance the angle measuring accuracy of CCD alignment in the wild environment. Beginning with each segment of angle measuring system,the plan analyzed various technological principlAimed at the weak anti-interference ability of traditional angle measuring system in the open field,a set of complete plan was proposed to enhance the angle measuring accuracy of CCD alignment in the wild environment. Beginning with each segment of angle measuring system,the plan analyzed various technological principles and also adopted corresponding technological steps in different segments,which mainly included technologies of semiconductor laser power constant control,optical spectrum matching and narrow-band filtering,CCD automatic changeable scan control and CCD frequency doubling interpolation subdivision,etc. The test result proves that the above mentioned method can enhance the anti-inference ability of CCD alignment in the wild environment and the system measuring accuracy..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 35, Issue 11, 57 (2008)
Depolarization Characteristics of the Polarized Laser in Atmosphere
YANG LI-hong, KE Xi-zheng, and MA Dong-dong
A Monte Carlo algorithm is presented to model characteristics of polarized laser in thick fog and thin fog media. When the wavelengths of polarized laser are equal,the depolarization characteristics of the polarized laser are analyzed separately in the different fog particle radii. And the changes of polarizing angle aA Monte Carlo algorithm is presented to model characteristics of polarized laser in thick fog and thin fog media. When the wavelengths of polarized laser are equal,the depolarization characteristics of the polarized laser are analyzed separately in the different fog particle radii. And the changes of polarizing angle are compared in the different transmitting range. The simulation result shows that,1) when the granule radius is small,the biggest changes of backward polarization angle are mainly centralized,and the changes of all forward polarization angles are very small. The forward scattering polarization angle of a single sphere granule is invariable; 2) more and more complex side lobes of polarization angles appear with the increase of the fog particle radius; 3) the diffused light polarization angles increase with the increase of optical transmission distances,and the depolarization angles of laser in thick fog are bigger than those in thin fog..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 35, Issue 11, 62 (2008)
Experiment Investigation of Water Breakdown Characteristic by High Power Laser
ZONG Si-guang, WANG Jiang-an, and WANG Yu-hong
An experimental investigation of the shock wave and cavitation bubble after optical breakdown in water with Nd:YAG laser pulses was presented. The experimental investigation of the laser-induced cavitation bubble expansion and collapse was done with high-speed video. The pressure acoustic signal generated by the cavitaAn experimental investigation of the shock wave and cavitation bubble after optical breakdown in water with Nd:YAG laser pulses was presented. The experimental investigation of the laser-induced cavitation bubble expansion and collapse was done with high-speed video. The pressure acoustic signal generated by the cavitation bubble was detected with the high-frequency measuring hydrophone. In general,the bubble characteristic generated by the laser is similar to the bubble characteristic generated by the propeller cavitation in a liquid. The laser energy affects the characters of laser-induced acoustic signal,such as signal intensity,signal appearance. The results of experiment investigation may serve for the optimization in the bubble study,applications of laser medicine,laser machining and laser-generated sound..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 35, Issue 11, 68 (2008)
Air Quality Detecting Based on FTIR and Spectrum Substraction
WANG Yan, ZHANG Yan-chao, LI Ning, and ZHAO Xue-hong
To realize multi-component analysis of air quality detecting,an gas quantitative method combining technique of Fourier Transform Infrared (FTIR) spectroscopy and the method of spectrum subtraction was applied. Based on Michelson micro-interference principle and Lambert-Beer law,FTIR spectrometer coupled with long path To realize multi-component analysis of air quality detecting,an gas quantitative method combining technique of Fourier Transform Infrared (FTIR) spectroscopy and the method of spectrum subtraction was applied. Based on Michelson micro-interference principle and Lambert-Beer law,FTIR spectrometer coupled with long path White gas cell was used to measure the infrared spectrums of the trace gases,and then,the values of gas concentration was deduced by the method of spectrum subtraction. Furthermore,for the gases to be detected,the regions were chosen carefully to provide optimum detection of the compounds interested with minimum interference by other compounds (especially,vapor and CO2). The optimal window for CO,SO2,NO2,NO and CO2 would be the regions at 2250～2020 cm-1,1230～1070 cm-1,2 940～2 840 cm-1,1 965～1 775 cm-1,and around 668.24 cm-1 respectively. The quantitative analysis for CO,SO2,NO2,NO and CO2 of different concentrations was carried out in this way. Results indicate that the values of relative errors are below 10%..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 35, Issue 11, 73 (2008)
Auto-focusing System Based on CCD Aerial Cameras
ZHAO Mei, MA Zhong-zhou, TANG Hai-yan, SHA Yu-fang, and ZHANG Yong
To get images of high quality with aerial camera,the focus of the lens and the situation of the real image plane must accord with the technical standards. A system is put forward which can automatically measure focus and estimate whether the aerial camera is off-focus and the situation of the real image plane is in theTo get images of high quality with aerial camera,the focus of the lens and the situation of the real image plane must accord with the technical standards. A system is put forward which can automatically measure focus and estimate whether the aerial camera is off-focus and the situation of the real image plane is in the focus plane range or not. The work principle,the hardware composition and the software design are discussed in detail. The system acquires examining-focus information with collimator,receives images information with CCD camera which can be regarded as optoelectric conversion apparatus,processes data with the center of gravity method,and realizes the axial flow of the CCD camera translation with the grating displacement sensor and the digital readout together. Then,the optimum image situation and the image size can be fixed on. The optimum image situation can be used to judge whether the camera is off-focus,and the image size can be used to calculate the focus. The accurate rate of examining focus can reach almost 99.87% and the estimation of off-focus or not accords with experiment result of flight..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 35, Issue 11, 77 (2008)
Coupling Duct for Slab Amplifier Pumping
ZHAO Tian-zhuo, FAN Zhong-wei, CUI Jian-feng, SHAN Xiao-nan... and GUO Fang|Show fewer author(s)
The coupling duct characteristics used in Laser Diode Array (LDA) pumped slab amplifiers was investigated by ray tracing. The ideal reflective characters were analyzed at first. And then,the coupling ducts with different parameters were simulated to prove the relation between coupling duct reflection and structure paraThe coupling duct characteristics used in Laser Diode Array (LDA) pumped slab amplifiers was investigated by ray tracing. The ideal reflective characters were analyzed at first. And then,the coupling ducts with different parameters were simulated to prove the relation between coupling duct reflection and structure parameters,which showed that ducts had its own loss and the relations between duct reflectivity and its structure parameters were obtained. The concept of duct side wall equivalent times of reflection was also put forward,which could be used to calculate the reflection loss on the side wall. After ray tracing and numerical fitting,an approximate mathematical expression was gotten,which could be well used to show the reflection situation of duct. Finally,an experiment about practical project design was done to prove the good precision of the simulation..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 35, Issue 11, 82 (2008)
Three-axis Ultraviolet Optical Sensor
WEI Zhi-jun, and LIU Xiao-jun
Three-axis Ultraviolet Optical Sensor (UVOS) is designed. The observation problem for a very wide field of view is solved in the orbit for near earth. By the irregular optical system that is reflecting arrays and combined optical system,the circular wide field of view is divided into 8 sub-fields. UVOS provides both thThree-axis Ultraviolet Optical Sensor (UVOS) is designed. The observation problem for a very wide field of view is solved in the orbit for near earth. By the irregular optical system that is reflecting arrays and combined optical system,the circular wide field of view is divided into 8 sub-fields. UVOS provides both three-axis attitude and autonomous navigation data by utilizing image-overlap and image-processing. Calibration precision for UVOS is under yaw angle 0.05°,pitch angle 0.05°and roll angle 0.05°. Engineering Model is finished. By means of observing star experiment and star simulator experiment,UVOS can measure 5 magnitudes. UVOS is one of the important sensors for space vehicles of deep space exploration.
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 35, Issue 11, 86 (2008)
Fast Angle Vector Computation Algorithm Based on Row Gray Projection Correlation for Rotation Image
TAO Sheng-xiang, ZHOU Ya-jun, ZHANG Jiang-hui, and SU Xiang
As current electronic image stabilization algorithms are weak in angle vector computation for rotation images,a fast angle vector computation algorithm based on row gray projection correlation was presented. By selecting reference frames areas and correlating their row gray projection areas in the center areas of curreAs current electronic image stabilization algorithms are weak in angle vector computation for rotation images,a fast angle vector computation algorithm based on row gray projection correlation was presented. By selecting reference frames areas and correlating their row gray projection areas in the center areas of current frames,angle vector between frames was computed. The principle of selecting projection and rotation areas was discussed. Through analyzing the correlation curves between row gray projection and column gray projection,the conclusion is educed that the row gray projection curve has single peak characteristic. Principle of fast searching algorithm and its application in this algorithm were explained. Experiment show that the algorithm realizes fast angle vector computation of rotation images sequence,and can compute any angle vector with high precision..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 35, Issue 11, 91 (2008)
Infrared Sequential Image Registration for the Tendency Analysis of Converter Inner-lining Wear
LIU Fei-fei, and DONG Shao-hua
For the tendency analysis of copper converter inner-lining wear,a new method of infrared sequential images registration based on the isotherm contour features was proposed. The most similar isotherm contour was sought by centroid distance function and Fourier descriptor. The parallelism point set was given on the similFor the tendency analysis of copper converter inner-lining wear,a new method of infrared sequential images registration based on the isotherm contour features was proposed. The most similar isotherm contour was sought by centroid distance function and Fourier descriptor. The parallelism point set was given on the similar isotherm contour,and the images registration space was built by projective transformation. The image registration problem was converted into the least square estimation problem of standard parameter matrix. The test result shows that the isotherm contour matching and images registration are found rapidly and simply by the method,which may attain the analytical precision of smelting plant..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 35, Issue 11, 96 (2008)
Robustness Analysis of Image Registration Measures to Overlay Area Changing
SHANGGUAN Jin-tai, GUO Hui, YUE Jin, and YANG Ru-liang
The robustness of registration measures is one of the most frequently considered problems in image registration process. The robustness of some dominant registration measures to overlay area changing is discussed by using statistic method. In addition,quantitative analysis is included. The results indicate that the linThe robustness of registration measures is one of the most frequently considered problems in image registration process. The robustness of some dominant registration measures to overlay area changing is discussed by using statistic method. In addition,quantitative analysis is included. The results indicate that the linear correlativity between these registration measures and overlay area is very prominent. Among these registration measures,the normalized mutual information [H(A)+H(B)]/H(A,B) has the smallest variation coefficient while Absolute Difference(AD)has the largest coefficient. Image registration using this normalized mutual information measures can reduce the performing time and speed up the image registration process in the condition of ensuring accuracy,which has been validated in the registration tests..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 35, Issue 11, 101 (2008)
Improved Image Fusion Algorithm Based on Local Energy
GONG Chang-lai
An image fusion algorithm based on local energy processing of wavelet coefficient is analyzed. To overcome its disadvantage of insufficient consideration for local pixel independent information,an improved algorithm is proposed. The improved algorithm combines the local energy selection and weighted average fusion ruleAn image fusion algorithm based on local energy processing of wavelet coefficient is analyzed. To overcome its disadvantage of insufficient consideration for local pixel independent information,an improved algorithm is proposed. The improved algorithm combines the local energy selection and weighted average fusion rule by using the phase information of window center pixel. When the high frequency wavelet coefficients of the two source images are the same in phase,maximum rule of local energy is used to select the high frequency wavelet coefficient of the fusion images. When the two coefficients are reversal in phase,weighted average rule of local energy is used to obtain the coefficient. Experiment results show the effectiveness of the improved algorithm..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 35, Issue 11, 106 (2008)
Optical Fiber Ring Resonator Based on Brillouin Fiber Optic Gyro
LI Xu-you, ZHANG Yong, WANG Rui, and HE Zhou
A method for designing optic fiber ring in Brillouin Fiber Optic Gyro (B-FOG) is presented. Based on the principle of Brillouin fiber optic gyroscope,the optical Jones matrix theory and stimulated Brillouin scattering classical theory are utilized to describe the characteristic of Brillouin optical resonator in detail.A method for designing optic fiber ring in Brillouin Fiber Optic Gyro (B-FOG) is presented. Based on the principle of Brillouin fiber optic gyroscope,the optical Jones matrix theory and stimulated Brillouin scattering classical theory are utilized to describe the characteristic of Brillouin optical resonator in detail. Through meticulous analysis of light intensity inside and outside the resonator,the requirement of coupling state and pump light intensity which the fiber ring resonator in B-FOG needs is obtained. In the end,the reasonable Brillouin fiber ring resonator in B-FOG is designed,and test results show that when this method is used to set B-FOG working point,the greatest transmission efficiency of the Stokes light is ensured and the granular noise is suppressed..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 35, Issue 11, 111 (2008)
Application of Passive Fiber-optic Probe to Detonation Experiments
WANG Rong-bo, LI Ze-ren, TIAN Jian-hua, WU Ting-lie, and HE Li-hua
A fiber-optic probe diagnostic system has been developed for measuring shock arrival time by taking advantage of shock-induced luminescence of fused quartz. When the shock front reaches the tip of the fiber probe,an intense optic pulse is produced. The visible pulse is transmitted via fiber to an opto-electrical converA fiber-optic probe diagnostic system has been developed for measuring shock arrival time by taking advantage of shock-induced luminescence of fused quartz. When the shock front reaches the tip of the fiber probe,an intense optic pulse is produced. The visible pulse is transmitted via fiber to an opto-electrical converter then to oscillograph for recording. The shock arrival times can be gotten by reading the signals recorded in oscillograph. The fiber-probe is passive and electromagnetic interference immunity,whose response time can reach sub-nanosecond. Metal and nonmetal materials can be directly measured by this sensor. At present,the probe has been greatly applied in the detonation testing experiments. This article introduces the fiber-sensor applications,such as the shock wave velocity of LY12 sample,the flatness of Mylar film loaded by electric blasting,and the detonation wave profile of GI-920 explosion..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 35, Issue 11, 117 (2008)
Variable Step-size Sign LMS Self-adaptive Filtering Method for Fiber Optic Gyro
ZHU Yan-hua, LIU Jian-ye, LAI Ji-zhou, and ZHOU Hai-bo
To reduce the random drift in Fiber Optic Gyro (FOG),a self-adaptive filtering method called variable step-size sign Least Mean Square (LMS) algorithm was presented. Considering the practical engineering requirement,some positive work was carried on based on the traditional LMS algorithm. On one hand,normalized power vTo reduce the random drift in Fiber Optic Gyro (FOG),a self-adaptive filtering method called variable step-size sign Least Mean Square (LMS) algorithm was presented. Considering the practical engineering requirement,some positive work was carried on based on the traditional LMS algorithm. On one hand,normalized power value of input signal was introduced to improve filtering accuracy and stability; on the other hand,sign function of error was used as well in order to decrease calculation burden and increase real-time performance. Besides,the step-size parameter was determined by convergence analysis. The actual static and rotation experiment results indicate that the new algorithm is able to select the step-size parameter in advance and with more favorable filtering stability,accuracy and real-time performance. The variable step-size sign LMS filtering method is suitable for engineering application..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 35, Issue 11, 122 (2008)
Spread Spectrum Watermarking Algorithm Based on Ridgelet Transform
HU Yu-feng, and ZHU Shan-an
A novel image watermarking algorithm was designed by taking the advantage that ridgelet transform domain is a more suitable representation of image’s linear outline edge features than wavelet transform. Firstly,the image was divided into blocks,and each block was transformed by finite ridgelet transformation. Secondly,A novel image watermarking algorithm was designed by taking the advantage that ridgelet transform domain is a more suitable representation of image’s linear outline edge features than wavelet transform. Firstly,the image was divided into blocks,and each block was transformed by finite ridgelet transformation. Secondly,the watermark was spread spectrum modulated by two zero mean and uncorrelated random sequences. At last,the modulated watermark was additively embedded in the high frequency coefficients of ridgelet transform domain. Experiment results show that the proposed algorithm can not only resist common attacks such as compression,noise,filtering and cropping,but also resist image gray enhancement and weakened attack. The comparison with wavelet transform domain watermarking algorithm also shows the advantages of the algorithm..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 35, Issue 11, 128 (2008)
Novel Fingerprint Minutiae Extraction Algorithm Using Hessian Matrix
LUO Jing, LIN Shu-zhong, NI Jian-yun, and ZHAN Xiang-lin
An algorithm of fingerprint minutiae extraction using Hessian matrix was proposed in order to overcome the shortcoming of Direct Gray-level Minutiae Detection (DGMD) proposed by Maio,etc.,which had the failure of minutiae extraction as a result of abrupt changes of the fingerprint ridge curvature. Combining the charactAn algorithm of fingerprint minutiae extraction using Hessian matrix was proposed in order to overcome the shortcoming of Direct Gray-level Minutiae Detection (DGMD) proposed by Maio,etc.,which had the failure of minutiae extraction as a result of abrupt changes of the fingerprint ridge curvature. Combining the characteristics of Hessian matrix eigenvectors and the geometry direction of fingerprint,the proposed algorithm tracked the ridges of fingerprint and extracted minutiae accurately. The experimental results based on FVC2000 show that the proposed algorithm can track the fingerprint ridge whose curvature changes abruptly. So the algorithm has achieved the total correct minutiae extraction rate of 95.5%. Moreover,the algorithm has better robustness and accuracy than DGMD algorithm and Hessian matrix algorithm..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 35, Issue 11, 134 (2008)
Investigation of Optical Components Polished with Polyurethane Pad
LI Ya-guo, WANG Jian, XU Qiao, YANG Wei... and GUO Yin-biao|Show fewer author(s)
The effect of high speed polishing process was investigated,which was applied to polish large optical flatware. Material removal rate as well as surface roughness was measured,which was used to evaluate the quality of optical component. The effect of pressure and spindle speed on material removal rate was researched,whThe effect of high speed polishing process was investigated,which was applied to polish large optical flatware. Material removal rate as well as surface roughness was measured,which was used to evaluate the quality of optical component. The effect of pressure and spindle speed on material removal rate was researched,which was up to 10um/h in our experiments. The results of experiments coincided with Preston formula. Moreover,the surface form of optical components polished by high speed polishing is ～1.0λ(λ=632.8 nm). Last,surface roughness induced by high speed polishing with different size polishing agents (300 and 500 mesh size) was also observed. Our results show that the surface roughness is proportional to the size of polishing agent which deceases with the time of use..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 35, Issue 11, 139 (2008)
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