Journals >Opto-Electronic Engineering
Contents
2010
Volume: 37 Issue 12
28 Article(s)
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Research Article
Design of Support for Large Aperture Primary Mirror
GUAN Ying-jun, and XIN Hong-wei
Support technology of large aperture space mirror is one of the key points for space camera development. The influences of stiffness, strength and thermal dimensional stability of the mirror component were considered in the process of support structure design. A support for Φ 980 mm primary mirror in Cassegrain space tSupport technology of large aperture space mirror is one of the key points for space camera development. The influences of stiffness, strength and thermal dimensional stability of the mirror component were considered in the process of support structure design. A support for Φ 980 mm primary mirror in Cassegrain space telescope was designed. The support scheme of six points support on back was proposed in which three points were main and the others were assistant. The problem that surface figure accuracy of large aperture primary mirror meets the demand in the gravity load, but out of errors under the load case of uniform temperature change was solved by adding flexible support. By adopting finite element analysis technique, the static and dynamic as well as thermal characters of primary mirror were analyzed. According to the analysis results, structural parameters of the flexible support were adjusted, and then reduce the influences of gravity, assembly stress and thermal stress on the primary mirror. Analysis and test results indicate that surface figure accuracy of the mirror reaches to PV<λ/10，RMS<λ/50 (λ=632.8 nm), the first natural frequency is 116 Hz, and the maximum stress is 65 MPa in the vibration test, which can meet the requirements for the primary mirror..
Opto-Electronic Engineering
- Publication Date: Oct. 12, 2021
- Vol. 37, Issue 12, 1 (2010)
Star Centroiding Algorithm for High-noising Situation
LIU Tai-yang, WANG Shi-cheng, LIU Zhi-guo, and YANG Jian-ye
Considering the difficulties in star centroiding computation of star image that is polluted by strong noises, a centroiding algorithm based on threshold judging with sub-window gray distribution static evaluation was proposed. With certain number of sub-windows with certain size chosen based on the image character, theConsidering the difficulties in star centroiding computation of star image that is polluted by strong noises, a centroiding algorithm based on threshold judging with sub-window gray distribution static evaluation was proposed. With certain number of sub-windows with certain size chosen based on the image character, the gray distribution was studied and the decentralization was calculated. After the judgment of decentralization according certain rules, sub-windows which contain peak noise regions or those unfavorable would be displaced by new chose ones. Hence, the threshold gray value final gained would represent the comprehensive character of the star image and the succeeding application of square-weighted subdivision algorithm could improve the succeeding centroiding algorithm’s accuracy. Simulation and result analysis proved a pleasant performance and robust capacity against sever peak noises of the proposed algorithm..
Opto-Electronic Engineering
- Publication Date: Oct. 12, 2021
- Vol. 37, Issue 12, 6 (2010)
Effect of Satellite Vibration on Imaging Quality of TDICCD Camera and Compensation Method
SHI Jun-xia, XUE Xu-cheng, and GUO Yong-fei
In order to realize image stabilization on vibrated image captured by an airborne TDICCD, the effect of satellite vibration on imaging quality of TDICCD is analyzed, and a method on compensation to satellite vibration is proposed. First, the principle of a TDICCD is introduced, and the characteristic that a TDICCD diffIn order to realize image stabilization on vibrated image captured by an airborne TDICCD, the effect of satellite vibration on imaging quality of TDICCD is analyzed, and a method on compensation to satellite vibration is proposed. First, the principle of a TDICCD is introduced, and the characteristic that a TDICCD differs from others is that a TDICCD is especially sensitive to vibration. Then, the effect of vibration on a TDICCD camera is analyzed by taking the MTF as an evaluation standard. As an emphasis, the relationship between vibration and TDICCD integration stage is researched. Finally, by using the satellite vibration data, the effect of satellite vibration on TDICCD is calculated. Results indicate that as the integration stage increases, MTF decreases greatly. When the integration stage increases to 54, the MTF decreases to below 0.95. Based on the analysis, vibration detecting method based on high-speed CCD and vibration compensating method based on vibration mirror are proposed to compensate the influence of satellite vibration. Aimed at the former，an improved gray projection algorithm is proposed to detect the parameters of satellite vibration, and the error is not more than half a pixel..
Opto-Electronic Engineering
- Publication Date: Oct. 12, 2021
- Vol. 37, Issue 12, 11 (2010)
High-speed Centroid Calculation of Spot Image without Multipliers
FAN Zhi-hua, and WANG Chun-hong
Spot centroiding is the key technique used in optical precise tracking and measurement, and its precision and speed affect those of optical tracking systems directly. In the applications, image pre-processing methods, which suppress the noise effectively at the expense of logic resources, are combined with the conventiSpot centroiding is the key technique used in optical precise tracking and measurement, and its precision and speed affect those of optical tracking systems directly. In the applications, image pre-processing methods, which suppress the noise effectively at the expense of logic resources, are combined with the conventional mass of gravity to improve the reliability of spot centroid calculation. In order to realize real-time spot detection with resources limited, a high-speed spot centroid calculation method without multipliers is proposed. Instead of multiplications, it uses additions in recursive way to compute all low order moments needed by spot centroding. Compared with the architecture of the conventional mass of gravity method, our method needs only five accumulators, thus the resource cost is much lower than that of multipler-based spot detection. Moreover, the operating frequency of the hardware implementation of our method is up to 515 MHz with parallel and pipeline architecture. Experimental results indicate that when implemented in Field Programmable Gate Array at 100 MHz, our design can determine the spot centroid accurately with latency no more than 0.35 us at the cost of 214 slices, which is only half of resource consumption of the conventional method..
Opto-Electronic Engineering
- Publication Date: Oct. 12, 2021
- Vol. 37, Issue 12, 17 (2010)
Image Restoration Based on Phase Diversity
WANG Zong-yang, WANG Jian-li, WANG Bin, and WU Yuan-hao
Phase Diversity (PD) method estimates both the wave-front phase and object by two focused and defocused images with known phase as the prior information. An image restoration experiment by using PD method was designed. The wave-front phase aberration caused by atmosphere turbulence was simulated by using the deformablePhase Diversity (PD) method estimates both the wave-front phase and object by two focused and defocused images with known phase as the prior information. An image restoration experiment by using PD method was designed. The wave-front phase aberration caused by atmosphere turbulence was simulated by using the deformable-mirror. Due to simplifying the optical system and eliminating the effect of chromatic aberration，the Offner reflector was used to design the reflective imaging system. Experiment results indicate that, compared with the origin image, the resolution of the restored image can increase by 12% and the ability of improving image resolution and phase estimation is verified. So the proposed method can be used as a good means to restore the degradative images in the large aperture telescope..
Opto-Electronic Engineering
- Publication Date: Oct. 12, 2021
- Vol. 37, Issue 12, 25 (2010)
A VSMM Algorithm Based on Unscented Digraph Switching for Maneuvering Target Tracking
HUANG Xiang-yu, and PENG Dong-liang
In the region of maneuvering target tracking, the traditional interacting multiple model algorithm has a fixed structure, which brings unnecessary inter-competition among the amount of models and calculation burden that the algorithm needs enough models to ensure the accuracy. To resolve this contradiction, a variable In the region of maneuvering target tracking, the traditional interacting multiple model algorithm has a fixed structure, which brings unnecessary inter-competition among the amount of models and calculation burden that the algorithm needs enough models to ensure the accuracy. To resolve this contradiction, a variable structure multiple-model algorithm based on digraph switching and unscented Kalman filter is presented. According to the target motion state basis at different times, the algorithm can match sub-model-set based on the digraph. Simulation results show that this algorithm improves the accuracy of tracking by reducing the competition of the models as well as reducing the computation burden..
Opto-Electronic Engineering
- Publication Date: Oct. 12, 2021
- Vol. 37, Issue 12, 30 (2010)
Multi-object Edge Extraction Based on GVF Snake
XIE Shan-shan, and MA She-xiang
An improved algorithm is presented based on the GVF Snake in order to achieve the multi-objective edge extraction. Firstly, the GVF Snake is used for carrying out the edge extraction of the whole object region, and the results will contain false edges because of the stagnation point region. Secondly, this false edge isAn improved algorithm is presented based on the GVF Snake in order to achieve the multi-objective edge extraction. Firstly, the GVF Snake is used for carrying out the edge extraction of the whole object region, and the results will contain false edges because of the stagnation point region. Secondly, this false edge is analyzed and a new initial contour is established automatically. Then, the GVF Snake is used again to carry out new edges extraction and to determine the real edge and false edge. In the end, those real edges are connected, which were extracted in above two steps, and remove the false edges to get the complete multi-objective edge. Experimental results show that the proposed algorithm can achieve the multi-objective edge extraction..
Opto-Electronic Engineering
- Publication Date: Oct. 12, 2021
- Vol. 37, Issue 12, 35 (2010)
A Microscope Measurement System of Cellular Mueller Matrix
LI Yu-bo, LI Shi-bo, CHEN Wei-jian, ZENG Yu-xiao, and YANG Jian-yi
A polarizing measurement system is designed which could acquire Mueller matrix of the target cells. The system utilizes a liquid crystal modulator bonding with polarization splitter prism as its key component, to realize Mueller matrix measurement with a period of 10-time light intensity. This method can easily acquireA polarizing measurement system is designed which could acquire Mueller matrix of the target cells. The system utilizes a liquid crystal modulator bonding with polarization splitter prism as its key component, to realize Mueller matrix measurement with a period of 10-time light intensity. This method can easily acquire real-time data divided from Mueller matrix, which is more efficient than other method. Besides the specific design and the experiment result are presented based on this system. The analysis and discussion of measurement error are also included, which indicates that this system’s error can be controlled within 2%..
Opto-Electronic Engineering
- Publication Date: Oct. 12, 2021
- Vol. 37, Issue 12, 41 (2010)
Effect of Optical Zoom and Scaling Algorithms on Image Resolution
WANG De-jiang, KUANG Hai-peng, LI Wen-ming, and CHEN Xi-hui
In order to study effect of optical zoom and scaling algorithms on image resolution, firstly, lens resolution, detector resolution and photographic resolution are discussed thoroughly. Then, differences between optical zoom and scaling algorithms are deduced from sampling theory. Finally, a resolution measurement systeIn order to study effect of optical zoom and scaling algorithms on image resolution, firstly, lens resolution, detector resolution and photographic resolution are discussed thoroughly. Then, differences between optical zoom and scaling algorithms are deduced from sampling theory. Finally, a resolution measurement system is established, and image of drones are obtained based on variable focus and scaling factors. Experimental results indicate that drone of 100 mm focus is vivid in edge and owns higher resolution, and drone of 50 mm amplified by one time is blurred in edge and owns lower resolution..
Opto-Electronic Engineering
- Publication Date: Oct. 12, 2021
- Vol. 37, Issue 12, 46 (2010)
A Surface Plasmon Resonance Sensor Based on Differential Intensity Detection
LIU Jin, and CHEN Bao-xue
Traditional surface plasmon resonance sensors have the shortcoming of needing expensive rotation or the spectrum equipment, so the method of differential detection for refractive changes with light intensity is presented and two LDs are used. This method is based on the surface plasmon resonance principle and variationTraditional surface plasmon resonance sensors have the shortcoming of needing expensive rotation or the spectrum equipment, so the method of differential detection for refractive changes with light intensity is presented and two LDs are used. This method is based on the surface plasmon resonance principle and variation of the refractive indices is measured by the optical intensity of two different wavelengths. The reference light path is designed to eliminate the fluctuation of light. Theoretical analysis and experimental results show that the sensitivity value of this method is twice as much as that of single-LD light intensity detection method, easy to implement instrument miniaturization. The angle detection device and the spectrometer are not used in the system, so the system can be potable and compact. Adjusting the incident angles and different wavelengths of light can be used to detect different range of refractive index..
Opto-Electronic Engineering
- Publication Date: Oct. 12, 2021
- Vol. 37, Issue 12, 50 (2010)
Lighting System Analysis of Visual Inspection of Strip-surface Scratch Defects
HU Rong-hua, YU Ming, and LIU Guo-ping
The low-angle and dark-field lighting system is set up with common array LED source for the strip-surface scratch defects. Meanwhile, illumination function in the given area is derived on the basis of LED lighting system, which receives the light intensity distribution function of LED by the curve fitting. The lightingThe low-angle and dark-field lighting system is set up with common array LED source for the strip-surface scratch defects. Meanwhile, illumination function in the given area is derived on the basis of LED lighting system, which receives the light intensity distribution function of LED by the curve fitting. The lighting system model is built based on the distribution function. and the Tracepro is used to simulate the lighting system model, and the relation is analyzed between the parameter β，S and illumination uniformity ΔE, which provides the corresponding basis for setting up the lighting system of visual inspection. Finally, the simulation results are verified through lighting experiments..
Opto-Electronic Engineering
- Publication Date: Oct. 12, 2021
- Vol. 37, Issue 12, 55 (2010)
Long Period Fiber Gratings with Complex Refractive Index Deposited Based on LP Modes
LUO Tao, and GU Zheng-tian
As the refractive index of the overlay is higher than that of the cladding, the Long Period fiber Grating (LPG) element exhibits high sensitivity. However, when the thickness of the overlay is tens of nanometers, the material of the overlay present a high absorption, and the absorption can impact the property of the LPAs the refractive index of the overlay is higher than that of the cladding, the Long Period fiber Grating (LPG) element exhibits high sensitivity. However, when the thickness of the overlay is tens of nanometers, the material of the overlay present a high absorption, and the absorption can impact the property of the LPG element. A numerical study based on the linearly polarized (LP) modes and the coupled-mode theory (CMT) is used for our research. The analyses mainly comprise the mode structure and the spectrum influenced by the transition intervals which include both the transition nearby and the transition apart. On the basis of the non-absorption ideal mode, we studied the transition and re-organization of the cladding modes caused by the absorption, as well as its impact on the spectrum of the LPG. The result shows that the absorption causes the sensitivity and the dynamic range of the LPG element changed. Finally, we present a new absorption LPG sensor element..
Opto-Electronic Engineering
- Publication Date: Oct. 12, 2021
- Vol. 37, Issue 12, 59 (2010)
Image Fusion Using Lifting Stationary Wavelet Transform and Adaptive PCNN
GUO Mao-yun, LI Hua-feng, and CHAI Yi
A novel image fusion algorithm based on the Stationary Lifting Wavelet Transform (SLWT) and adaptive Pulse Coupled Neural Network (PCNN) is proposed. Compared with the traditional PCNN where the linking strength of each neuron is the same, this adaptive PCNN uses the sharpness of each pixel as its value, so that the liA novel image fusion algorithm based on the Stationary Lifting Wavelet Transform (SLWT) and adaptive Pulse Coupled Neural Network (PCNN) is proposed. Compared with the traditional PCNN where the linking strength of each neuron is the same, this adaptive PCNN uses the sharpness of each pixel as its value, so that the linking strength of each pixel can be chosen adaptively. By using a stationary lifting wavelet transform, we can calculate a flexible multiscale and shift-invariant representation of registered images. A Novel Sum-Modified-Laplacian (NSML) in the low frequency subbands and the pixels value of high frequency subbands of SLWT are input into motivate adaptive PCNN, respectively. The coefficients in SWLT domain with large firing times are selected as coefficients of the fused image. Experimental results demonstrate that the proposed fusion approach outperforms the traditional discrete wavelet transform-based SLWT-based and SLWT-PCNN-based image fusion methods in terms of both visual quality and objective evaluation..
Opto-Electronic Engineering
- Publication Date: Oct. 12, 2021
- Vol. 37, Issue 12, 67 (2010)
Efficient SAR Image Segmentation Based on Non-grid MRF in High Noise Background
CHEN Hua-jie, and WU Xiang-wei
Image segmentation model based on Markov Random Field (MRF), which combines prior knowledge and likelihood information, have the certain ability to preserve image boundary and reduce speckle noise. However, the method in SAR image with high noise background is difficult to balance reduction of noise and preservation ofImage segmentation model based on Markov Random Field (MRF), which combines prior knowledge and likelihood information, have the certain ability to preserve image boundary and reduce speckle noise. However, the method in SAR image with high noise background is difficult to balance reduction of noise and preservation of boundary because of the abilities based on neighborhood structure. If the neighborhood structure is simple, the algorithm can keep the image boundary, but cannot reduce noise well. Besides, the pixel processing unit in the iterative optimization stage of the method led to massive inefficiencies, and can not meet the requirements of practical application. Thus, a new segmentation strategy is proposed. Firstly, the original image is partitioned into many small segments which have similar grayscale and good boundary. Secondly, in order to enhance the ability of reducing noise of the method, each image pixel gray value is set as the average of the segment to which the pixel belongs. Finally, in iterative optimization stage of the algorithm, each segment in place of pixels was used as the processing units, which reduce the amount of processing unit and improve the efficiency of the algorithm. In order to demonstrate our algorithm’s performance, simulated and real SAR image’s segmentation results are presented..
Opto-Electronic Engineering
- Publication Date: Oct. 12, 2021
- Vol. 37, Issue 12, 75 (2010)
Anomaly Detection for Hyperspectral Image Based on SVDD with Negative Examples
PU Xiao-feng, LEI Wu-hu, TANG Jun-jie, and HUANG Tao
Anomaly detection algorithm based on the Support Vector Data Description (SVDD) usually brings low detection rates due to background examples being contaminated by anomalous data. To deal with the problem, a new method based on SVDD with negative examples is proposed. By leading into the origin and a few anomalies as nAnomaly detection algorithm based on the Support Vector Data Description (SVDD) usually brings low detection rates due to background examples being contaminated by anomalous data. To deal with the problem, a new method based on SVDD with negative examples is proposed. By leading into the origin and a few anomalies as negative examples, the capability of description to anomaly and background is improved. In order to control the influence of false examples, the distance of each sample deviating from the mean of background example is mapped into the sample as weighting coefficient. The results show that the proposed method could obtain higher detection rate under low false rate than the algorithm based on SVDD. The effectiveness of the proposed method is validated by experimental results obtained from real data..
Opto-Electronic Engineering
- Publication Date: Oct. 12, 2021
- Vol. 37, Issue 12, 83 (2010)
Interactive Volumetric Three-dimensional Display Based on Dynamic Hand Gesture Control
PAN Wen-ping, SHEN Chun-lin, ZHANG Zhao-xing, and XING Jian-fang
Tracking and recognition algorithms for dynamic hand gestures have been studied and interactive volumetric three-dimensional (3D) display based on dynamic hand gesture control has been implemented. Volumetric 3D display can present images with physical depth cues in the true 3D space, where images can be viewed from alTracking and recognition algorithms for dynamic hand gestures have been studied and interactive volumetric three-dimensional (3D) display based on dynamic hand gesture control has been implemented. Volumetric 3D display can present images with physical depth cues in the true 3D space, where images can be viewed from almost any angle without any special eyewear. With vision-based hand gesture control, viewers can interact with volumetric 3D display from any viewpoint. Firstly, tracking region containing a special static hand posture is initialized from frame-differencing images. Meanwhile, a skin color model is built based on the region. Then positions of KLT features in the initial region are updated using optical flow tracking method and adjusted with the “flock of features” algorithm and the learned skin color model. Thereafter, through coordinate transformation and encoding according to eight-directional Freeman chain code, gesture observation sequence is generated for recognition. Finally, a pre-specified gesture symbol is decided by Hidden Markov Model (HMM) evaluation using a trained gesture HMM set. Experiments are conducted for the interactive volumetric display based on dynamic hand gesture control. Experimental results show that with these gesture tracking and recognition algorithms, the average recognition rate is high up to 93%, the average response time is less than 40 ms, and interactions can be well performed from arbitrary viewpoint..
Opto-Electronic Engineering
- Publication Date: Oct. 12, 2021
- Vol. 37, Issue 12, 88 (2010)
Region-of-interest Image Coding for Satellite Application Based on Saliency of Visual Attention
TIAN Xin, WEI Jiao-long, WANG Chun-ming, and TIAN Jin-wen
To satisfy the demand for high-fidelity remote sensing image transmission in the limited channel, a Region-of-interest (ROI) image coding algorithm based on the saliency of visual attention is proposed. Firstly, the CCSDS coding framework can reduce the computing complexity, which is suitable for real-time applicationsTo satisfy the demand for high-fidelity remote sensing image transmission in the limited channel, a Region-of-interest (ROI) image coding algorithm based on the saliency of visual attention is proposed. Firstly, the CCSDS coding framework can reduce the computing complexity, which is suitable for real-time applications (such as satellite application). Secondly, an automatic ROI extraction algorithm, which is based on the saliency of visual attention, is proposed. Finally, the ROI is determined by using the mask and can be used for arbitrary shape. The experimental results have demonstrated that, compared with the algorithm in JPEG2000, the proposed algorithm is easy to be implemented. Moreover, it has good subjective visual quality, which is consistent with the human visual perception. Meanwhile, the proposed algorithm could be a ROI algorithm used for CCSDS standard..
Opto-Electronic Engineering
- Publication Date: Oct. 12, 2021
- Vol. 37, Issue 12, 96 (2010)
A Method for Optical Remote Sensing Image Ship Extraction in Cloudy Sea Background
CHEN Yan, and GONG Yu-chang
Ship extraction is usually a challenging problem because of different complicated backgrounds, including coarse sea surface, clouds and shadows. A new cloud over ship model is proposed according to the features of intensity and whether the cloud has a shadow or not. Firstly, shape prior is introduced based on shape disShip extraction is usually a challenging problem because of different complicated backgrounds, including coarse sea surface, clouds and shadows. A new cloud over ship model is proposed according to the features of intensity and whether the cloud has a shadow or not. Firstly, shape prior is introduced based on shape distance metrics. An energy function is then constructed in which shape energy is computed according to the similarity of the shape information of the ship and its corresponding shape template. Secondly, the energy function is minimized based on graph cut theory. The experiment results show efficiency of ship extraction in cloudy sea backgrounds in optical remote sensing images whether there is a cloud shadow or not..
Opto-Electronic Engineering
- Publication Date: Oct. 12, 2021
- Vol. 37, Issue 12, 103 (2010)
Driven Design and Test of MEMS Optical Wavelength Selector
SUN Zhi-dan, LIANG Zhong-zhu, and LIANG Jing-qiu
By combining micro-machine with micro-assembly techniques, the 1×8 Optical Wavelength Selector (OWS) has been realized. The OWS based on Micro-Electro-Mechanical System (MEMS) technology is composed of electromagnetic optical switch, reflecting prisms, thin films filters and fiber collimators. The driving control By combining micro-machine with micro-assembly techniques, the 1×8 Optical Wavelength Selector (OWS) has been realized. The OWS based on Micro-Electro-Mechanical System (MEMS) technology is composed of electromagnetic optical switch, reflecting prisms, thin films filters and fiber collimators. The driving control circuit is designed for the 1×8 OWS. The test system of the response time and the insertion loss is designed and built for the 1×8 OWS. The response time and insertion loss of the 1×8 OWS has been measured. The final experimental results of the 1×8 OWS include the response time of about 15 ms and the insertion loss of about 2.5 dB..
Opto-Electronic Engineering
- Publication Date: Oct. 12, 2021
- Vol. 37, Issue 12, 110 (2010)
Concatenated Space-time Block Code in Atmosphere Laser Communication
WANG Hui-qin, CAO Ming-hua, and JIA Ke-jun
Space-time Block Code (STBC) can achieve full diversity gain, but it can not provide code gain. So the system error rate capability will be restricted. In this paper, the optical Multiple Input Multiple Output (MIMO) system channel model was introduced at first. Then, for Q-PPM (Q>2) modulation, the existing STBC isSpace-time Block Code (STBC) can achieve full diversity gain, but it can not provide code gain. So the system error rate capability will be restricted. In this paper, the optical Multiple Input Multiple Output (MIMO) system channel model was introduced at first. Then, for Q-PPM (Q>2) modulation, the existing STBC is amended. Moreover, by concatenating RS code, a concatenated STBC is proposed and its upper bound of error rate is analyzed. At last, the feasibility of this method is proved by the simulation experiment result. Compared the result with repetition code that concatenated RS code, it is shown that in atmosphere laser communication, the concatenated STBC can provide higher code gain..
Opto-Electronic Engineering
- Publication Date: Oct. 12, 2021
- Vol. 37, Issue 12, 116 (2010)
Analysis of Tuning Wavelength Filter Based on One-dimensional Ternary Photonic Crystal Containing Electro-optical Material LiNbO3
LIU Xiao, ZHOU Jun, TAN Xiao-ling, SUN Yong-tang, and JIN Li
A new one-dimensional ternary photonic crystal containing electro-optical material LiNbO3 is proposed. Based on transmit matrix method, the photonic band-gap varied with external field is simulated and analyzed in near infrared region. The simulation results show that the defect mode is found to merge inside photonic bA new one-dimensional ternary photonic crystal containing electro-optical material LiNbO3 is proposed. Based on transmit matrix method, the photonic band-gap varied with external field is simulated and analyzed in near infrared region. The simulation results show that the defect mode is found to merge inside photonic band-gap with the impact of external field, and the peak wavelength of defect mode can be tuned by adjusting the external field. Moreover, the angle-dependent peak position of defect mode is also examined, which opens a promising way to design tunable wavelength filters in near infrared region..
Opto-Electronic Engineering
- Publication Date: Oct. 12, 2021
- Vol. 37, Issue 12, 122 (2010)
White LEDs Packing Technology of Planar Phosphor Coating Layer
WAN Yuan-tao, RAO Hai-bo, and GAO Han-song
Based on the self-exposure planar phosphor coating technique, which adopted a kind of water-soluble sensitive glue consisting of Polyvinyl Alcohol (PVA) and Ammonium Dichromate (ADC). This method adopted the blue light exposure by itself which could obtain controllable phosphor layer. Finally, by using the plasma stripBased on the self-exposure planar phosphor coating technique, which adopted a kind of water-soluble sensitive glue consisting of Polyvinyl Alcohol (PVA) and Ammonium Dichromate (ADC). This method adopted the blue light exposure by itself which could obtain controllable phosphor layer. Finally, by using the plasma stripping, only phosphor’s planar coating layer could be obtained. Luminous efficiency, spectrum of light output and color uniformity of different packing structures were measured by the nine point’s method. Experimental results show that the uniformity of white LED obtained by this technique is better than that obtained by the traditional dropping glue technology and sprays coating technology. And the luminous efficiency is as good as the other two technologies..
Opto-Electronic Engineering
- Publication Date: Oct. 12, 2021
- Vol. 37, Issue 12, 127 (2010)
Polarization-independent Phase-only Variable Retarder
JIANG Ji-jun, SHEN Zhi-xue, ZHANG Da-yong, LI Jian-feng, and LIU Hai-tao
A polarization-independent phase-only Liquid Crystal (LC) phase retarder was demonstrated by using two orthogonal identical Liquid Crystal Variable Retarders (LCVR). Based on Jones matrix theory, the relationship of polarization state between input beam and output beam was deduced. And the Stokes parameters were measurA polarization-independent phase-only Liquid Crystal (LC) phase retarder was demonstrated by using two orthogonal identical Liquid Crystal Variable Retarders (LCVR). Based on Jones matrix theory, the relationship of polarization state between input beam and output beam was deduced. And the Stokes parameters were measured on the condition that the voltage individually applied to the two LCVRs was 1.55 V and 1.49 V. It is proved that the structure well operates in polarization-independent modulation. And the phase variation induced by voltage from 1~2.7 V is given out..
Opto-Electronic Engineering
- Publication Date: Oct. 12, 2021
- Vol. 37, Issue 12, 131 (2010)
A Kind of Control System Based on XC164CS and Visual Inspection
WANG Xu-dong, YE Yu-tang, CHEN Dong-ming, CHEN Yu, WU Jian-ping, and PU Liang
16-bit microcontroller is used to control system as the core controller. Moving parts are driven by position-servo-system. Buttons switch, adjustable stroboscopic light source and fiber optic sensors are isolated by high-speed opto-couple TLP521-4. Optical fiber sensors and servo encoder feedback signals, complementing16-bit microcontroller is used to control system as the core controller. Moving parts are driven by position-servo-system. Buttons switch, adjustable stroboscopic light source and fiber optic sensors are isolated by high-speed opto-couple TLP521-4. Optical fiber sensors and servo encoder feedback signals, complementing each other, were combined in the controller design. Through the analysis and design of the control system, the analysis of the relationship between the exposure time and light frequency and the analysis of relationship between the CCD image acquisition frequency, in-depth research and demonstration are done. The control system has been successfully applied to the appearance of PCB optical inspection machine. Experiments show that the system has many significant properties, such as high precision, small error，high stability and flexibility of parameter changing..
Opto-Electronic Engineering
- Publication Date: Oct. 12, 2021
- Vol. 37, Issue 12, 136 (2010)
Correlation Analysis Identification for High Precision Servo System with Stribeck Friction
WANG Xuan, ZHANG Juan-mei, and ZHOU Yang
The accuracy of servo system model affects the analysis and design of controllers directly. The non-linear friction has adverse effects on the high-precision servo system, and the control-oriented system identification is an vitual way to the system analysis recognization.The correlation analysis method can reduce noisThe accuracy of servo system model affects the analysis and design of controllers directly. The non-linear friction has adverse effects on the high-precision servo system, and the control-oriented system identification is an vitual way to the system analysis recognization.The correlation analysis method can reduce noise strongly, and identify system’s discrete difference model directly. Therefore, it is still widely used. This paper analyzes the effect of Stribeck friction on the servo system at low speed ,and identifys the system by correlation analysis method with a compensated excitation. Then the excitation parameters are analyzed and derived, and the concrete steps is listed. The experimental results show that the method can improve the accuracy of servo system identification with nonlinear frictions..
Opto-Electronic Engineering
- Publication Date: Oct. 12, 2021
- Vol. 37, Issue 12, 143 (2010)
Wireless Meter Reading System with Advance Payment Based on Opto-electrical Structure
ZHAO Yong, and SU Xian-yu
Wireless meter reading system with advance payment based on opto-electrical structure is introduced in this paper. By using wireless route technique, the long range transfers with little power are implemented. And the data transmission channels possess self-healing function when route is blocked. The manners like advanWireless meter reading system with advance payment based on opto-electrical structure is introduced in this paper. By using wireless route technique, the long range transfers with little power are implemented. And the data transmission channels possess self-healing function when route is blocked. The manners like advance payment of cell phone is adopted as expense manage means. Shortcoming of current meter reading system is improved. Actual operation validates feasibility and practicability of the system..
Opto-Electronic Engineering
- Publication Date: Oct. 12, 2021
- Vol. 37, Issue 12, 147 (2010)
[in Chinese]
[in Chinese]
Opto-Electronic Engineering
- Publication Date: Oct. 12, 2021
- Vol. 37, Issue 12, 151 (2010)
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