Journals >Opto-Electronic Engineering
Contents
2009
Volume: 36 Issue 3
27 Article(s)
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Research Article
Orthogonally Linearly-polarized Lasers and Its New Application in Precision Measurement
ZHANG Shu-lian, and TAN Yi-dong
Orthogonally linearly-polarized lasers and its new applications in precision measurement are presented, including: 1) orthogonally linearly-polarized lasers, 2) principle for laser nanometer ruler (displacement sensor based on the competition between two polarized lights of the frequency splitting lasers), 3) principleOrthogonally linearly-polarized lasers and its new applications in precision measurement are presented, including: 1) orthogonally linearly-polarized lasers, 2) principle for laser nanometer ruler (displacement sensor based on the competition between two polarized lights of the frequency splitting lasers), 3) principle for phase retardation measurement using frequency splitting technology, 4) principle for phase retardation measurement based on laser feedback effects. These novel principles have remarkable characteristics of simple structure, tracing back to optical wavelength. The laser nanometer ruler has been applied in practical occasions, and its performance is as follows: the measurement range 12 mm, resolution 79 nm, and linearity less than 5×10-5. The repeatability reaches 0.3′ for phase retardation measurement system based on frequency splitting technology. However, laser feedback phase retardation measurement system has the advantage of on-line measuring..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 3, 1 (2009)
Frequency Estimation Algorithm of Laser Doppler Signal
WANG Ji-qiang, FENG Di, TIAN Lun, ZHANG Chun-xi, OU Pan, and JIA Yu-dong
The characteristics of laser Doppler echo signal are analyzed and a frequency estimation algorithm of laser Doppler signal is presented. The auto-correlation function of signal is obtained by Fast Fourier Transform (FFT) and coarse estimating frequency is acquired from the power spectrum, and then the auto-correlation The characteristics of laser Doppler echo signal are analyzed and a frequency estimation algorithm of laser Doppler signal is presented. The auto-correlation function of signal is obtained by Fast Fourier Transform (FFT) and coarse estimating frequency is acquired from the power spectrum, and then the auto-correlation function is shifted in frequency domain with coarse estimating frequency. The frequency offset is obtained by computing the phase of frequency-shifted signal’s auto-correlation function at one point. The frequency estimation value is acquired by the correction of coarse frequency with frequency offset. The results gotten above and the symmetry of FFT gene can be used to decrease computation complexity. Simulation demonstrates that the method has lower Root Mean Square Error (RMSE) and Mean Absolute Error (MAE). Applied to laser Doppler velocimetry experiment, the result is accordance with simulation..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 3, 12 (2009)
Linear Array Push-broom Method in Laser Imaging Fuze Detection Technology
SUN Zhi-hui, DENG Jia-hao, and YAN Xiao-wei
In laser imaging fuze detection technology, a linear array push-broom imaging method was proposed to solve the problem in circle-scan imaging method such as needing scanning mechanism and high pulse repetition frequency laser. The principle of linear array push-broom imaging method was analyzed in detail. Linear array In laser imaging fuze detection technology, a linear array push-broom imaging method was proposed to solve the problem in circle-scan imaging method such as needing scanning mechanism and high pulse repetition frequency laser. The principle of linear array push-broom imaging method was analyzed in detail. Linear array push-broom imaging detection system which consists of linear diode laser array and linear photodiode array was designed to detect tank target. One dimensional scanning was performed by linear array device itself and the other one dimensional scanning was performed by forward velocity of the munition. The image of target was generated based on range information. Basic design parameters of the system including the number of array elements, the size of the image, the pulse repetition frequency and the peak power of linear diode laser array, were chosen based on the calculation of the element laser footprint size. The methods of choosing basic design parameters provide guideline for hardware realization of the system..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 3, 16 (2009)
A New Algorithm of Target Tracking
QI Li-feng, FENG Xin-xi, XI Xiao-ping, and BAI Jian-lin
Aiming at complicated computing and difficulty of being realized when extending single sensor PHD filtering to the multi-sensor case by means of probability generating function, a multi-sensor multi-target sequential particle-PHD tracking algorithm is proposed based on the thought of sequential filtering for a centraliAiming at complicated computing and difficulty of being realized when extending single sensor PHD filtering to the multi-sensor case by means of probability generating function, a multi-sensor multi-target sequential particle-PHD tracking algorithm is proposed based on the thought of sequential filtering for a centralized fusion system. The algorithm chooses the importance density function with regard to every sensor, and updates sample particle of every sensor layer by layer. Finally, the multi-sensor multi-target sequential PHD tracking is realized. Experimental results show, when multi-target is tracked only using single sensor, some particles can deviate true trajectories of target, which causes the error of estimated numbers of targets. However, the multi-sensor multi-target sequential particle-PHD tracking algorithm can reduce distance error and improve tracking accuracy effectively..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 3, 22 (2009)
Video Object Tracking Based on Particle Filter with Genetic Evolution Strategy
XI Tao, ZHANG Sheng-xiu, YUAN Kui, and YAN Shi-yuan
Particle degeneration distinctly jeopardizes the visual tracking performance in particle filter. In order to deal with this shortcoming, an improved particle filter with genetic evolution strategy is addressed. In the proposed algorithm, the degeneracy problem is solved by applying the selection operator of genetic algParticle degeneration distinctly jeopardizes the visual tracking performance in particle filter. In order to deal with this shortcoming, an improved particle filter with genetic evolution strategy is addressed. In the proposed algorithm, the degeneracy problem is solved by applying the selection operator of genetic algorithm to choose the suboptimal samples iteratively based on the predefined likelihood threshold, and then the crossover and mutation operation are implemented to the samples which are not selected, so the diversity of the particles is maintained. Furthermore, considering the object appearance changes, the multi-template is employed to adaptively update the appearance of tracked object for keeping the accuracy in the scenario of tracking. The experiment results show that the proposed visual tracking algorithm can effectively track the moving object in the real-time indoor video sequences and is robust to the illumination and pose variations..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 3, 28 (2009)
Local Feature Spatial Correlation Kernel for Image Object Classification
CHEN Hai-lin, WU Xiu-qing, and HU Jun-hua
For representing the relative location relationship of local features in the image space, local feature Spatial Correlation Kernel (SCK) is proposed for image object classification. The local features in the image are extracted and quantized, and the spatial location auto-correlations are calculated for vector-quantizeFor representing the relative location relationship of local features in the image space, local feature Spatial Correlation Kernel (SCK) is proposed for image object classification. The local features in the image are extracted and quantized, and the spatial location auto-correlations are calculated for vector-quantized local features, and then the histogram intersection is used to match spatial location auto-correlations of two images to obtain the local feature spatial correlation kernel. The proposed kernel makes good use of both the powerfully discriminative ability of local features and their spatial locations. Furthermore, SCK has a linear computation cost, satisfies the positive definite condition and could be used for kernel-based learning algorithms. The experiments performed on the public image database by embedding SCK into the support vector machine to classify the image objects demonstrate that SCK achieves the good time efficiency and the good classification performance..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 3, 33 (2009)
Virtual Test Scene Simulation System for Theodolite
ZHANG Yong, JIANG Ping, and WU Qin-zhang
Virtual test scene simulation is an important method for testing capabilities of optoelectronic theodolite system in the lab. A general function structure of the virtual test scene simulation system was established. This system mainly provides the virtual scene and simulation image for virtual test. Methods of the virtVirtual test scene simulation is an important method for testing capabilities of optoelectronic theodolite system in the lab. A general function structure of the virtual test scene simulation system was established. This system mainly provides the virtual scene and simulation image for virtual test. Methods of the virtual target track modeling and the target pose simulation for the target motional characteristics, and the background cloud simulation in the scene simulation were proposed. Moreover, the target pose interference, the noise influence and the grey distribution were discussed in the scene image simulation. This simulation system was developed by the combination of VC++ and OpenGL. Simulation tests show that virtual test scene and the synthesis image of the target and background are effective in testing tracking capabilities of theodolite..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 3, 39 (2009)
Design and Realization of Fuzzy PI Algorithm for Stability Control of Photoelectric Stabilized Platform
YUN Ping-ping, HONG Hua-jie, LEI Jin-li, and ZHAO Chuang-she
Stability control is one of the core technologies of the photoelectric stabilized platform servo control. It is difficult for classical control way to deal with the conflict between the overshot and rapidity and to get satisfied dynamic performance. The system mathematical model for stability control was built, a self-Stability control is one of the core technologies of the photoelectric stabilized platform servo control. It is difficult for classical control way to deal with the conflict between the overshot and rapidity and to get satisfied dynamic performance. The system mathematical model for stability control was built, a self-tuning fuzzy PI controller was designed by combining the rapid response of fuzzy control with the steady state zero error of PI control, and the relation of the controller parameters was analyzed. Theoretical calculations and simulation analysis of the control system were carried out. The designed controller was realized by software on a digital platform based on DSP. Control performance test experiment of the control system was conducted. The simulations and experiments show that the new designed control system reaches the goal of zero overshot and rapid response..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 3, 46 (2009)
Optical Properties Analysis of Compound Parabolic Refractive X-ray Lenses
LE Zi-chun, and LIU Wei
The Compound Parabolic Refractive X-ray Lenses (CPRXLs) are a kind of novel optical components, especially suitable for hard X-rays. Due to their parabolic profiles, they are free of spherical aberration and are genuine devices for sub-micrometer focusing and imaging. The properties of a rotationally symmetric paraboliThe Compound Parabolic Refractive X-ray Lenses (CPRXLs) are a kind of novel optical components, especially suitable for hard X-rays. Due to their parabolic profiles, they are free of spherical aberration and are genuine devices for sub-micrometer focusing and imaging. The properties of a rotationally symmetric parabolic X-ray lens are studied theoretically and numerically in this paper. Firstly, the exact focal length formula is derived by using matrix optics method and a criterion of the thin lens approximation is obtained. Secondly, according to the diffraction theory, intensity distribution near focus is analyzed, which can give the limited focal spot size. Finally, the theoretical formulas of effective aperture and the transmittance are deduced. In addition, the numerical results of the designed CPRXLs made of various materials are also shown..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 3, 52 (2009)
Shoreline Detection Method in Video Images Based on Radon Transform and Gradient Tracking Algorithm
ZHANG Suo-ping, and ZHANG Chun-tian
To extract shoreline from video monitoring images, a method is proposed by applying Radon transform and gradient tracing algorithm. Based on the different color properties of land and water image, the gradient vector is calculated to present edges in color space efficiently. Then, with Radon transform and its basic abiTo extract shoreline from video monitoring images, a method is proposed by applying Radon transform and gradient tracing algorithm. Based on the different color properties of land and water image, the gradient vector is calculated to present edges in color space efficiently. Then, with Radon transform and its basic ability of linear singularity detection, a profile analysis technique is used to further select the corresponding peak area. Meanwhile, the approximate direction and area of waterline is obtained in the Radon domain. In addition, the image region including interface of shore and sea boundaries is located by reconstructing image using inverse Radon transform. Finally, the shoreline is determined by an improved searching strategy to explore the maximum gradient path. Experimental results indicate that the proposed approach is effective in finding the shorelines and the algorithm has robustness with varies lightening conditions..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 3, 57 (2009)
Hausdorff Distance Based on Edge-strength and Its Application on Object Location
CHEN Ying, and ZHENG Jin-rong
Object location is a principal problem in the field of machine vision. In order to eliminate the negative effects of noises, an improved Hausdorff distance based on edge-strength was proposed for object location. Edge length, edge gradient and edge closure were used for edge weights computation, and a location functionObject location is a principal problem in the field of machine vision. In order to eliminate the negative effects of noises, an improved Hausdorff distance based on edge-strength was proposed for object location. Edge length, edge gradient and edge closure were used for edge weights computation, and a location function was then established by adopting weighted Hausdorff distance. Distribution estimation algorithm concerning related multi-variables was used to avoid local minimum during optimization, which described the relationship between matching parameters with a probability model. The tasks of location were realized by probability model evolution. Experiments show that the algorithm outperforms other approaches in both accuracy and rapidity..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 3, 63 (2009)
Restoration of the Image Blurred by Motion Based on High-speed CCD Motion Detection
FU Zhong-liang, FENG Hua-jun, XU Zhi-hai, LI Qi, and MAO Cheng-jun
This paper provides a new method to restore the image blurred by any motion and a corresponding system for experiments is established. Previous restoration methods can only be useable when the motion is special, for example, uniform rectilinear motion, which is solved in the paper. During the integral time of prime CCDThis paper provides a new method to restore the image blurred by any motion and a corresponding system for experiments is established. Previous restoration methods can only be useable when the motion is special, for example, uniform rectilinear motion, which is solved in the paper. During the integral time of prime CCD, a series of images used to compute the displacement, are captured by the low resolution white-black CCD. And then, the instantaneous speed can be computed. From the theoretic analysis, we know that the Point Spread Function (PSF) has corresponding relationship with the instantaneous speed. Then the PSF for restoring the blurred image can be worked out. Finally, the Richard-Lucy (RL) method is used to restore the blurred image. The experiment shows that, for any motion blurred images, this method for image restoration can get preferable results..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 3, 69 (2009)
Method of Image Compression for Optical Wavelet Transform
JI Yan-li, TIAN Feng-chun, LIU Guo-jin, and XU Xin
Since the wavelet transformation caused a great deal of data and occupies a long time, image data compression on optical system was realized. The characteristics of optical system and optical wavelet coefficients were analyzed in detail and simulation was done on several quantization encoding methods. Then, appropriateSince the wavelet transformation caused a great deal of data and occupies a long time, image data compression on optical system was realized. The characteristics of optical system and optical wavelet coefficients were analyzed in detail and simulation was done on several quantization encoding methods. Then, appropriate compression method was put forward and lossy compression was realized. In addition, by analyzing the endurance to quantity noise of optical system, an important conclusion was achieved that the ideas of nearly lossless compression was sparked. Experimental results show that, compared with the directly reconstructed image, the PSNR of nearly lossless reconstructed image is only 0.1 dB, and there is no significant difference in vision..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 3, 74 (2009)
Detecting Obstacles in Grass by Fusing Range and Color Information
XIANG Zhi-yu, and WANG Wei
A novel method for detecting obstacles in grass is proposed by fusing information from ladar and camera. Firstly, training range data is acquired by a 3-D ladar, and shape feature parameters of obstacles and grass are calculated respectively. Using Expectation Maximization (EM) algorithm, the Gaussian Mixture Model (GMA novel method for detecting obstacles in grass is proposed by fusing information from ladar and camera. Firstly, training range data is acquired by a 3-D ladar, and shape feature parameters of obstacles and grass are calculated respectively. Using Expectation Maximization (EM) algorithm, the Gaussian Mixture Model (GMM) which represents the distribution of shape features is learned. With these learned models, the 3-D points of candidate obstacles in the scene can be obtained. Meanwhile, mean-shift algorithm is applied to the corresponding color image to acquire the region information of the scene. With the result of joint calibration of the 3D ladar and the camera, those candidate obstacle points are projected to the segmented image and fusion is then performed to make the final decision. Experimental results show that the proposed method can distinguish obstacles from grass effectively with high precision and low false-alarm..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 3, 79 (2009)
Dissolved Oxygen Sensor Based on Biconical Shaped Plastic Optical Fiber
CHU Feng-hong, YANG Jun-jie, CAI Hai-wen, QU Rong-hui, and FANG Zu-jie
A dissolved oxygen sensor is reported based on plastic optical fiber as sensor head and light transmit element. In order to enhance the systems sensitivity, the sensor head is bent into biconical-shape, and dissolved oxygen concentration is measured based on fluorescence quenching phenomenon. Dichlorotris (1, 10-phenanA dissolved oxygen sensor is reported based on plastic optical fiber as sensor head and light transmit element. In order to enhance the systems sensitivity, the sensor head is bent into biconical-shape, and dissolved oxygen concentration is measured based on fluorescence quenching phenomenon. Dichlorotris (1, 10-phenanthroline) ruthenium (II) is used as fluorescence indicator and Sol-gel method is used to prepare the sensor material. According to Stern-Volmer equation, the dissolved oxygen concentration is linear with fluorescence intensity. We measure the relationship between dissolved oxygen concentration and fluorescence intensity and find that they are sub-linearity. In order to explain this phenomenon, we propose a model. By conic fitting the measured curve, the conclusion is drawn that 85% sensitivity film is not affected by dissolved oxygen..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 3, 84 (2009)
Research of F-P Optical Fiber Stress Sensor
GAO Xiao-ding, GAO Peng, and WANG Xu
The principle of F-P optical fiber stress sensor was analyzed，The Mathematical mold of F-P Optical fiber stress sensor was proposed. An elastic structure of F-P Optical fiber stress sensor and photoelectric conversion circuit was designed. APC circuit was used in the design of F-P Optical fiber stress sensor light sourThe principle of F-P optical fiber stress sensor was analyzed，The Mathematical mold of F-P Optical fiber stress sensor was proposed. An elastic structure of F-P Optical fiber stress sensor and photoelectric conversion circuit was designed. APC circuit was used in the design of F-P Optical fiber stress sensor light source circuit. The APC circuit was made up of two operational amplifiers, transistor and periphery circuit, and adopted backward photorefractive feedback offset control, which used laser diode module of PD photodiode to watch the backward output optical power. A calibration test of static state characteristic for F-P Optical fiber stress sensor was made. The test indicates that the sensor has high measure precision, which can meet the requests of project measuring..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 3, 88 (2009)
An All-fiber Interleaver Using Four Directional Couplers
ZHANG Bao-ge, WANG Tian-peng, and LU Huai-wei
An all-fiber interleaver of Cascaded M-Z Interferometer (CMZI) composed of two 2×2 and two 3×3 fiber couplers with almost rectangular wavelength response was developed by using a new configuration. Based on the principle of characteristics of fiber transmissivity, the complex amplitude output spectra were estAn all-fiber interleaver of Cascaded M-Z Interferometer (CMZI) composed of two 2×2 and two 3×3 fiber couplers with almost rectangular wavelength response was developed by using a new configuration. Based on the principle of characteristics of fiber transmissivity, the complex amplitude output spectra were established and described by the expression using the matrix transfer function. The analytical results indicate that when the third length difference of interference arms is as twice as the first length difference of interference arms, the coupling coefficient of the couplers is some certain values, and then a uniform flattop passband and similarity to square spectral response can be obtained by the configuration. The passband and stopband of optical interleaver are improved remarkably and the interval of peak output power is 1.6 nm. A filter of novel structure is fabricated by using the fused biconical taper technologies in experiment. The experiment results are in good agreement with the analytical ones..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 3, 93 (2009)
IHS Remote Sensing Image Fusion Based on Imaging Model
LIU Peng, LIU Ding-sheng, and LI Guo-qing
To reduce the spectral distortion in IHS fusion, fusion process was analyzed by spectral response function, bias and gains of the CCD sensor based on imaging mechanism, and it was simulated from spectral density to the panchromatic images and multi-spectral image. Condition equation was set up to maintain the spectral To reduce the spectral distortion in IHS fusion, fusion process was analyzed by spectral response function, bias and gains of the CCD sensor based on imaging mechanism, and it was simulated from spectral density to the panchromatic images and multi-spectral image. Condition equation was set up to maintain the spectral properties in IHS image fusion, and a new model of fusion was established based on the simplified process. Furthermore, the least square method was used to determine the relationship between the different spectral response functions in fusion process, and then the required parameters were calculated. Finally, we did experiments by using the true QuikBird image data and compared proposed method with others. Experiments show the proposed algorithm not only enhances the spatial resolution of the images but also maintains spectral characteristics better..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 3, 97 (2009)
Overall Visual Statistical Model for Object Recognition on Remote Sensing Image
LIU Wei, and TIAN Jin-wen
The overall visual statistical model is put forward based on the structural model. This model not only considers the local features of the objects but also considers the spacial information between objects. The model of local parts which are chosen depending on application, and the model of connection between parts areThe overall visual statistical model is put forward based on the structural model. This model not only considers the local features of the objects but also considers the spacial information between objects. The model of local parts which are chosen depending on application, and the model of connection between parts are built separately which are expressed by graph model. We simplify the problem by minimizing the energy function into MAP problem based on the statistical model. In this paper, this model is applied to the typical object recognition of remote sensing image and this model works well not only on single target detection but also on multiple target localization..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 3, 102 (2009)
Restoration of Remote-sensing Images Based on Meteorologic Data
WANG Zhen-guo, GENG Ze-xun, ZHAO Zhen-lei, SUI Xue-lian, and WANG Lan
For China and Brazil Earth Resource Satellite (CBERS-02) Remote-sensing (RS) image data, a novel deblurring algorithm is proposed by using the estimated atmosphere Modulation Transfer Function (MTF) through meteorologic data when imaging. In this method, both turbulence and aerosol MTFs are all estimated via meteorologFor China and Brazil Earth Resource Satellite (CBERS-02) Remote-sensing (RS) image data, a novel deblurring algorithm is proposed by using the estimated atmosphere Modulation Transfer Function (MTF) through meteorologic data when imaging. In this method, both turbulence and aerosol MTFs are all estimated via meteorological parameter measured by local weather station on the time when and in the region where the RS images were recorded. The product of these two MTFs is used as the total atmospheric MTF which is incorporated with a reformative Wiener filter. Experimental result shows that MTF curve covering area of restoration image is obviously bigger than that of original image and the validity and feasibility of this method is further testified..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 3, 110 (2009)
Novel Design of Drive and Test System for TDI IRCCD
LAI Rui, ZHOU Hui-xin, LI Qing, and WANG Bing-jian
Based on the idea of visual interactive control, a novel drive and test system for Time-delay Integration (TDI) IRCCD is presented. Being different from traditional drive circuit system, the newly developed system can accurately generate arbitrarily adjustable drive signals and feed back the device characteristic paramBased on the idea of visual interactive control, a novel drive and test system for Time-delay Integration (TDI) IRCCD is presented. Being different from traditional drive circuit system, the newly developed system can accurately generate arbitrarily adjustable drive signals and feed back the device characteristic parameters, simultaneously. Especially, the system consists of two parts, which are Host-computer-subsystem (HCS) and Slave-computer-subsystem (SCS). The HCS, being man-machine interface of the whole system, accomplishes parameter input and testing results display, while the SCS constructed with Single Chip Micyoco (SCM) and Field Programmable Gate Array (FPGA), fulfils the electronic parameter adjustment for drive signals according to the data sent from HCS or stored in data-store unit, and implements the electronic injection test for the IRCCD. It is validated that some intrinsic defects of the traditional design, such as less flexibility and poor reliability, are successfully eliminated in this new designed system..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 3, 115 (2009)
A Method for Calibrating Non-Uniformity of Multiple CCD Images Based on Scene
LIU Chang, LI Hui-zhuo, FAN Yong, and TANG Zun-lie
The factors which lead to non-uniformity of images are very complex. The conventional methods for calibrating non-uniformity of multiple Charge Coupled Device (CCD) imaging can not consider all of these factors. According to the characters of non-uniform images of multi-CCD, a calibrating method based on the scene was The factors which lead to non-uniformity of images are very complex. The conventional methods for calibrating non-uniformity of multiple Charge Coupled Device (CCD) imaging can not consider all of these factors. According to the characters of non-uniform images of multi-CCD, a calibrating method based on the scene was proposed by using the theory of two-point calibration and finding out the linearity of the images. Compared with the conventional two-point calibration and multi-point calibration methods, contrastive calibrating results were obtained. This method can calibrate the scene images without standard illumination images, which provides an effective way for online calibrating the multiple CCD imaging system in practical application..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 3, 120 (2009)
FUV Imaging Spectrometer Based on Crossed Czerny-Turner Structure
WU Yan, TANG Yi, NI Guo-qiang, BAI Ting-zhu, and HUANG Gang
This article introduced the needs and key technologies of the Far Ultraviolet (FUV) imaging spectrometer. The design method and spectral calibration were researched. The FUV imaging spectrometer was based on crossed Czerny-Turner optical structure with all reflective components in it. The initial structure was calculatThis article introduced the needs and key technologies of the Far Ultraviolet (FUV) imaging spectrometer. The design method and spectral calibration were researched. The FUV imaging spectrometer was based on crossed Czerny-Turner optical structure with all reflective components in it. The initial structure was calculated based on the primary aberrations theory, and the optical system whose effective wavelength range is from 100 nm to 300 nm was simulated and optimized by the optical design software Zemax in order to advance the spectral resolution. The crossed Czerny-Turner spectrometer system was set up and the spectral calibration and imaging ability test were achieved. The measured spectral bandwidth is less than 1.67 nm..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 3, 125 (2009)
Super-resolution Focus Property of Photon Sieves
LI Ya-wen, CHEN Jun-ning, JIA Jia, ZHU Xiao-li, WU Xuan, and XIE Chang-qing
Photon sieves were successfully designed after patterns optimization, and the focusing ability of 355 nm laser was investigated and compared with traditional Fresnel zone plates through experiments. Firstly, optimal patterns of photon sieves were automatically generated by the macro program. Secondly, photon sieves andPhoton sieves were successfully designed after patterns optimization, and the focusing ability of 355 nm laser was investigated and compared with traditional Fresnel zone plates through experiments. Firstly, optimal patterns of photon sieves were automatically generated by the macro program. Secondly, photon sieves and zone plates with 2 μm critical dimension were fabricated for focusing 355 nm lasers. Finally, with focusing-spot testing system, the focusing spot of 355 nm laser was gained for photon sieves and zone plates, and diameters of focusing spots were measured. The experimental results indicate that photon sieves have promising ability to achieve finer focusing spot and suppress more side lobe than zone plates..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 3, 130 (2009)
Manufacturing and Testing of a SiC Unrotational-symmetric Aspherical Optics
YAN Feng, FAN Di, ZHANG Bin-zhi, YIN Long-hai, LI Rui-gang, and ZHANG Xue-jun
It is presented that a SiC unrotational-symmetric aspherical optics whose surface equation is z=3λ(x3+y3) (where x, y is normalized coordinate, λ=0.632 8 μm, Φ150 mm) has been manufactured. Both digital-controlled polishing and hand working are used to modify the surface figure. The tilt component is subtracted to miniIt is presented that a SiC unrotational-symmetric aspherical optics whose surface equation is z=3λ(x3+y3) (where x, y is normalized coordinate, λ=0.632 8 μm, Φ150 mm) has been manufactured. Both digital-controlled polishing and hand working are used to modify the surface figure. The tilt component is subtracted to minimize the material removal without any effect on the surface figure in the polishing process. The material removal of the lowest point on the surface is 3.8 μm before subtracting tilt, while the removal is 2.06 μm after subtracting tilt. A non-null testing method based on digital mask is proposed to test this surface. The Zygo interferometer with flat reference wavefront is applied. The testing result can be divided into three parts: the derivation between the actual surface figure and the ideal one, the derivation between ideal surface figure and the reference wavefront, and the non-null error. The second part can be calculated ahead and made the system error of testing process with the transforming tool of Metropro. Thus, it can be eliminated automatically in the testing process. The third part is proven to have little effect on testing result by an experiment of testing a known sphere model, so it can be ignored. Thereby, the surface figure error (the first part) can be obtained within single measure. The final surface figure is 0.327λ (PV) and 0.025λ (RMS) by means of the non-null testing method, which achieves the prospective goal..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 3, 135 (2009)
Ear Detection Method in Complex Background
LIU Jia-min, and ZHU Sheng-jun
Based on the research of human-face detection, existing ear-detection methods are investigated in this paper, and a new optimized detecting method is presented to solve difficulties in ear detection such as small region, few common features, complex background and so on. Firstly, images are segmented into different regBased on the research of human-face detection, existing ear-detection methods are investigated in this paper, and a new optimized detecting method is presented to solve difficulties in ear detection such as small region, few common features, complex background and so on. Firstly, images are segmented into different regions with skin-color information and potential candidate regions are selected. Secondly, prior knowledge of side-face is applied to eliminate impossible regions. Thirdly, image edge is detected in different scales and ears are detected according to the rich edge information of human ear. In this method, the skin information of color image and multi-scale edge of grey image are combined with human ear features, which are employed to solve the problem that common features of ear image are difficult to extract in complex background. Experimental results show that this method is effective in complex background..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 3, 140 (2009)
Maximum Information Recording and Simplified Phase-shifting Technique in Digital Holography
QIU Pei-zhen, WANG Hui, JIN Hong-zhen, and SHI Yi-le
Based on information theory, the relationship between the information content of digital holography and recording optical structure was studied. In-line Fourier transform holography which could realize the maximum information content recording was proved. Meanwhile, a new simplified phase-shifting digital holographic mBased on information theory, the relationship between the information content of digital holography and recording optical structure was studied. In-line Fourier transform holography which could realize the maximum information content recording was proved. Meanwhile, a new simplified phase-shifting digital holographic microscopy that can effectively eliminate the zero order and conjugate virtual image was proposed. In this technique, a quarter-wave plate was used as the phase-shifting device, and the original reference wave was simulated by computer. This technique just needs phase once, only two digital holograms and an intensity image of object wave. With the combination of the new phase-shifting technique and in-line lensless Fourier transform holography, the phase-shifting process is simplified and the reconstructed image is outputted by maximum pixels. Thus, the resolution of the reconstructed image is improved obviously..
Opto-Electronic Engineering
- Publication Date: Oct. 08, 2021
- Vol. 36, Issue 3, 146 (2009)
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