Contents
2009
Volume: 29 Issue 11
55 Article(s)
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Atmospheric Optics and Oceanic Optics
Research on the Depoalrization Ratio Characteristic of the Aerosol in the Atmosphere with the CALIPSO Satellite Data
Zhao Yiming, Jiang Yuesong, Zhang Xuguo, and Lu Xiaomei
The depolarization ratio of the targets in the atmosphere was caculated from the CALIPSO satellite data.From the results it can be seen that the depolarization ratio can characterize the category,the characteristic and the verticle altitude of the aerosol in the atmosphere.The depolarization ratio of the aerosol applieThe depolarization ratio of the targets in the atmosphere was caculated from the CALIPSO satellite data.From the results it can be seen that the depolarization ratio can characterize the category,the characteristic and the verticle altitude of the aerosol in the atmosphere.The depolarization ratio of the aerosol applies the new method and believable parameter for the research of the aerosol.And the CALIPSO satllite data analyse result of this paper also gives new insight into the research about the reason of the global climate change,the pollution of the atmosphere,Saharan dust and other types of aerosol..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 2943 (2009)
Study on Aero-Optical Distortion Simulation of High Refraction Index Gradient Regions in Hypersonic Turbulent Flow
Wu Lin, Fang Jiancheng, and Yang Zhaohua
Based on the interfacial-fluid-thickness method,a mathematical model of the high gradient threshold of refractive index was established and the aero optical propagation effects of high gradient region in hypersonic flow was simulated.A gradient threshold using its harmonic mean was proposed.The density fields of hypersBased on the interfacial-fluid-thickness method,a mathematical model of the high gradient threshold of refractive index was established and the aero optical propagation effects of high gradient region in hypersonic flow was simulated.A gradient threshold using its harmonic mean was proposed.The density fields of hypersonic turbulence obtained from computational fluid dynamics were used to analyse refractive gradient magnitudes and aero optical distortions.Refractive index gradients whose absolute values were below the threshold were set to zero and the new refractive index field was reconstructed.Using the ray tracing algorithm of variable index-of-refraction,aero optical distortions of the original and reconstructed refractive index fields of different cross-sections,different flow conditions were simulated numerically and analyzed synthetically.The comparisons revealed that,using the threshold,the two dimensional correlation coefficients of the original and the reconstructed index-of-refraction fields were high to above 0.9,the relative error of the root mean square of optical path difference was not more than ±5%.Through the numerical simulations,the effectiveness and adaptability of the threshold proposed was validated and it also showed that the high index-of-refractive gradient region in hypersonic turbulent flow was the main reason in aero optical distortions..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 2952 (2009)
Propagation of Partially Coherent Vortex Beams in the Turbulent Atmosphere
Fu Wenyu, Li Gaoqing, and Liu Xiaojun
Based on the extended Huygens-Fresnel principle,the spatial correlation properties of partially coherent vortex beams in the turbulent atmosphere are studied synthetically in the paper.It is shown that the spectral degree of coherence and intensity of partially coherent vortex beams depend on topological charges,spatiaBased on the extended Huygens-Fresnel principle,the spatial correlation properties of partially coherent vortex beams in the turbulent atmosphere are studied synthetically in the paper.It is shown that the spectral degree of coherence and intensity of partially coherent vortex beams depend on topological charges,spatial relative coherence length and refractive index fluctuation et al.In the turbulent atmosphere,the spectral degree of coherence is shown to possess phase singularities,with the increase of spatial relative coherence length,coherence vortex gradually evolves into intenlsity vortex.Oppositely,with the increase of refractive index fluctuation,intensity vortex evolves into coherence vortex..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 2958 (2009)
Error Analysis of Equivalent Spheres Model for Computing the Reflection Properties of Ice Clouds
Sun Xianming, Shen Jin, Liu Wei, and Wang Haihua
The single scattering properties of the hexagonal ice crystals with a gamma particle size distribution were calculated by using the ray-optical theory at some wavelengths located in the visible and infrared spectral region(0.2-5 μm).The single scattering properties of the sphere particles having equal surface area withThe single scattering properties of the hexagonal ice crystals with a gamma particle size distribution were calculated by using the ray-optical theory at some wavelengths located in the visible and infrared spectral region(0.2-5 μm).The single scattering properties of the sphere particles having equal surface area with hexagonal ice crystals are calculated with Mie theory.Based on radiative transfer theory,the reflection properties of cirrostratus consisting of hexagonal ice crystals or equivalent spheres are computed by using the adding-doubling method,respectively.The results show that the Mie scattering calculations at the region of λ≈3.0 μm give good agreement with the hexagonal ice crystals.However,there are large errors at the region of λ<2.8 μm,especially,at the visible region.Finally,the schemes for calculations of the optical properties of ice clouds are proposed..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 2963 (2009)
Atomic and Molecular Physics
Spectrum Analysis and Level Lifetimes of Au48+ in Au Laser Plasma
Zhu Zhiyan, Zhu Zhenghe, Zhang Li, and Jiang Gang
The results of inertia confinement fusion (ICF) experiment indicate that the spectra of laser Au plasma contains the transitions of 3d4p,3d4f and 3p5d of Au48+.Based on the extended relativistic multi-configuration Dirac-Fock theory and the General-Purpose Relativistic Atomic Structure Program 2 (GRASP2) with quantuThe results of inertia confinement fusion (ICF) experiment indicate that the spectra of laser Au plasma contains the transitions of 3d4p,3d4f and 3p5d of Au48+.Based on the extended relativistic multi-configuration Dirac-Fock theory and the General-Purpose Relativistic Atomic Structure Program 2 (GRASP2) with quantum electrodynamical effect (QED) and Breit correction,the transition wavelengths,level lifetimes and level widths of Au48+ have been calculated.The transitions mentioned above have been considered in the calculation.The wavelengths obtained are in good agreement with the experimental data available.The relationship between the level lifetimes and the level widths satisfies with the,Heisenberg uncertainty principle.The results provide reference valuable for average ionic lifetime,charge state distribution and average ionization degree of Au plasma..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 2968 (2009)
Diffraction and Gratings
Studies on the Pulse response Characters of Large Chirped Fiber Bragg Grating
Che Yaliang, Luo Kaibin, and Du Tinglong
The pulse-stacking technology is one of the schemes of generating arbitrary seed pulse in the high power laser system which is used to spread the broadband short pulse to satisfy the need of the pulse-stacking components due to the wideband character of the large chirped fiber Bragg grating (LCBG).The reflect spectrum The pulse-stacking technology is one of the schemes of generating arbitrary seed pulse in the high power laser system which is used to spread the broadband short pulse to satisfy the need of the pulse-stacking components due to the wideband character of the large chirped fiber Bragg grating (LCBG).The reflect spectrum and the time delay of LCBG were simulated through the transmission matrix method.As a result,the dispersion and bandwidth depend on the chirp factor of LCBG,but the cost to increase the dispersion is the reduced bandwidth.The results also show that the bandwidth would be increased remarkably with longer LCBG,but at the same time the dispersion was invariable.These results are significant for designing the front-end of the high power laser system..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 2973 (2009)
Fiber Optics and Optical Communications
Accurate Computation of the Bit Rate Error in Differential Phase-Shift Keying-Balanced Direct Detection Receiver of High Speed Optical Communication Systems
Han Qingsheng, Li Wei, Mei Junyao, Huang Dexiu, and Sun Jun
The derivation of the probability density function (PDF) of differential nonlinear phase noise in diffrential phase-shift keying (DPSK)-balanced direct detection receiver of the high speed optical communication system is achieved by using the Gaussian approximation and Fourier transform methods.Finally,the result is usThe derivation of the probability density function (PDF) of differential nonlinear phase noise in diffrential phase-shift keying (DPSK)-balanced direct detection receiver of the high speed optical communication system is achieved by using the Gaussian approximation and Fourier transform methods.Finally,the result is used in computing the bit error rate (BER) considering all the noises influenced the transmission performance of the DPSK-balanced receiver system.The results have been verified by simulations through VPI software..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 2977 (2009)
Misalignment Analysis of Optical Interconnects Based on Non-Diffracted Beams
Wang Zhongyu, and Li Meng
The performance of optical interconnects utilizing non-diffracted beams under different misalignment conditions was analyzed.The signal-to-noise ratio (SNR) was used as the performance index,and the integral optical crosstalk of adjacent channels and detector pre-amplifier thermal noise were treated as the main noise.TThe performance of optical interconnects utilizing non-diffracted beams under different misalignment conditions was analyzed.The signal-to-noise ratio (SNR) was used as the performance index,and the integral optical crosstalk of adjacent channels and detector pre-amplifier thermal noise were treated as the main noise.The results show that the pitch and size of detectors can be used as optimization parameters for maximal misalignment tolerance and a high SNR.Increasing of detector radius and decreasing of spacing between detectors can tolerate greater misalignment,but the spacing cannot be too small in order to achieve an acceptable SNR.Moreover,optical interconnects using non-diffracting beams has the advantage that it is not affected by longitudinal misalignment..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 2984 (2009)
Effects of Photon-Number-Splitting Attacks on the Security of Satellite-to-Ground Quantum Key Distribution Systems
Chen Yan, Yang Hongyu, and Deng Ke
The security of practical quantum key distribution (QKD) systems based on weak coherent pulse (WCP) sources is imperiled by photon number splitting (PNS) attacks due to imperfectness of devices and channel loss.The relation between the zenith angle and the mean photon number for security of a satellite-to-ground QKD syThe security of practical quantum key distribution (QKD) systems based on weak coherent pulse (WCP) sources is imperiled by photon number splitting (PNS) attacks due to imperfectness of devices and channel loss.The relation between the zenith angle and the mean photon number for security of a satellite-to-ground QKD system based on the WCP source against PNS attacks which operates with the optimal eavesdropping strategy is provided.The theoretical and calculation results shows the upper limits of key parameters for satellite-to-ground QKD systems,such as the zenith angle and the mean photon number,are limited by PNS attacks,and eventually the key exchange rate and the capacity of QKD systems are limited as well.The zenith angle and the mean photon number have an incompatible effect on the capacity of a satellite-to-ground QKD system.At the same time a method of parameter estimation of the zenith angle and the mean photon number for security of practical satellite-to-ground QKD systems against PNS attacks is provided..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 2989 (2009)
Self-Similar Propagation and Amplification of High-Power Pulses in Large Mode Area Ytterbium Doped Fiber
Xu Dangpeng, Wang Jianjun, Lin Honghua, Deng Ying, Zhang Rui, and Li Mingzhong
The self-similar solutions of the nonlinear Schrdinger equation for the high-power pulses propagated and amplified in the gain fiber are analyzed,which result showing that when the pulse duration and energy satisfied the certain relation,the seed pulse can be propagated and amplified in the gain fiber by optimizing theThe self-similar solutions of the nonlinear Schrdinger equation for the high-power pulses propagated and amplified in the gain fiber are analyzed,which result showing that when the pulse duration and energy satisfied the certain relation,the seed pulse can be propagated and amplified in the gain fiber by optimizing the length of the gain fiber.The key self-similar evolution parameters of the seed pulse in the gain fiber are investigated.When the injection energy is 400 pJ and the pulse duration is 200 fs,the propagation and amplification characteristics of the secant,Gaussian,and super Gaussian seed pulses propagated and amplified in the large mode area gain fiber whose core diameter is 30 μm are numerical simulated.The results show that the temporal and spectral profiles of the three kinds of seed pulses are evolved into parabolic profiles and broadened.However,there are strong oscillations structure on the edges of the spectral profile.Moreover,the output pulse is linearly chirped parabolic pulse,which is easy to compress and has very important significance for realizing the all fiber high power ultra-short pulse generation system..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 2994 (2009)
Image Processing
Blind Image Restoration Algorithm Based on Wavelet Transform and NAS-RIF Algorithm
Guo Yongcai, Gao Chao, and Wang Enuo
An improved nonnegativity and support constraints recursive inverse filtering (NAS-RIF) algorithm based on wavelet transform is presented to restore blind images.The degraded image is decomposed to obtain its wavelet coefficients in wavelet domain.The image′s different frequency sub-bands are also obtained.Then,NAS-RIFAn improved nonnegativity and support constraints recursive inverse filtering (NAS-RIF) algorithm based on wavelet transform is presented to restore blind images.The degraded image is decomposed to obtain its wavelet coefficients in wavelet domain.The image′s different frequency sub-bands are also obtained.Then,NAS-RIF algorithm is used to restore degraded image in each sub-bands,different regularization terms are used in different sub-bands.By estimating the noise variance in each sub-bands,the adaptive regularization parameters can be calculated through the local properties of the observed image and the noise variance.The two simulating experiments are made and high signal to noise ratios (SNR) of 19.66 dB and 23.86 dB are obtained.The experimental results show that the method given by authors is more efficient than traditional space-adaptive regularization method..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3000 (2009)
An Algorithm of Adjacent Frame Matching Used for Head-on Point Targets Tracking
Wang Ledong, Wang Jiang′an, Kang Sheng, Zong Siguang, and Zhou Runzhi
Aiming at the detecting and tracking of head-on point targets in complicated sea-sky background,an algorithm that could detect while tracking is proposed based on adjacent frame matching.The algorithm obtains the interest region by the adjacent frame matching in infrared image sequences,adopts a mark image to memorize Aiming at the detecting and tracking of head-on point targets in complicated sea-sky background,an algorithm that could detect while tracking is proposed based on adjacent frame matching.The algorithm obtains the interest region by the adjacent frame matching in infrared image sequences,adopts a mark image to memorize the match result,adopts a statistical image to count the marking times of each pixels and outputs the statistical image to show head-on targets with input images.The algorithm is unique in no need to suppose the doubtful target points in advance;the single match process has nothing to do with other frames,and the whole match process does not change with the target movement state or the numbers of targets.Especially,the algorithm solves the head-on targets detection problems under the highly noisy condition.According to the simulations and experiments under the different condition time after time,it has been confirmed that the advantage above with high application value is different from the traditional algorithms and this method is of feasibility and validity..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3004 (2009)
A Segmentation Algorithm for High-Resolution Remote Sensing Texture Based on Spectral and Texture Information Weighting
Wang Leiguang, Liu Guoying, Mei Tiancan, and Qin Qianqing
High-spatial-resolution remote sensing imagery provides a large amount of spectral and structure information.However,their availability also poses challenges to conventional spectral segmentation methods,and the segmenation region is often too fragmentary and has low accuracy.In order to overcome this inadequacy,texturHigh-spatial-resolution remote sensing imagery provides a large amount of spectral and structure information.However,their availability also poses challenges to conventional spectral segmentation methods,and the segmenation region is often too fragmentary and has low accuracy.In order to overcome this inadequacy,texture information is introduced into spectral feature space.In the algorithm,the new feature space consists of spectral and texture elements,and weighted minimum distance classifier is designed.Firstly,spectral feature is got by a variable bandwidth mean shift filtering procedure on original images,and texture feature is got by convolving original image with multiscale Gabor filter bank band by band.Secondly,the weight of certain feature dimension for a certain land class is determined by its deviation in the land class training area.Then,the clustering centre is also calculated by averaging weighted feature vectors in the training area.Finally,every pixel is classified into the class with nearest weighted distance.The experiments demonstrate that the presented band definition method using the variable mean shift filtering is effective and the combination of different features can achieve better performance than only using texture or spectral feature independently..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3010 (2009)
An Adaptive Color Image Enhancement Algorithm Based on Human Visual Properties
Kang Mu, and Wang Baoshu
For the sensitivity to noise of some image enhancemext methods,an adaptive image enhancement algorithm is proposed.Using the basic principle of the original method,the parameters of the algorithm is adaptively generated according to the human visual properties.Firstly,the proposed algorithm can keep the original advantFor the sensitivity to noise of some image enhancemext methods,an adaptive image enhancement algorithm is proposed.Using the basic principle of the original method,the parameters of the algorithm is adaptively generated according to the human visual properties.Firstly,the proposed algorithm can keep the original advantages such as easy realization and quick calculation.Secondly,it plays a certain part in restraining noise.Finally,it can enhance and reserve the detail information.By comparing with other image enhancement algorithms,the proposed algorithm can get parameters of algorithm automaticly.Besides the easy realization of original method,the new algorithm also can improve the performance in restraining noise.At the same time,it can be used to enhance color image..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3018 (2009)
A Total-Variation Majorization-Minimization Sectioned Restoration Algorithm with Gradient Ringing Metric Image Quality Assessment
Tao Xiaoping, Feng Huajun, Zhao Jufeng, Li Qi, and Xu Zhihai
For eliminating the ringing artifacts between the sub-frames of the sectioned restoration algorithm for images with space-variant point spread function (SVPSF),the paper introduces a sectioned restoration algorithm,which bases on total variation(TV) majorization-minimization restoration algorithm and gradient ringing mFor eliminating the ringing artifacts between the sub-frames of the sectioned restoration algorithm for images with space-variant point spread function (SVPSF),the paper introduces a sectioned restoration algorithm,which bases on total variation(TV) majorization-minimization restoration algorithm and gradient ringing metric (GRM) image quality assessment approach.Firstly,the SVPSF-blurred image is divided into rectangular sections,circular sections or any other,which relies on the distribution of the degradation function,with some overlapped-regions.Then,each sub-section is restored by TV restoration algorithm with GRM as the convergence limit of restoration iteration.The GRM method is helpful to identify ringing of restored image,which relies on the similarity of the gradients of two images.After removing the overlapped regions,the sub-frames are spliced together to construct the composite full image.Taking the restorations of the rectangular-section and circular-section SVPSF-blurred images as examples,the paper proves that the algorithm is good at suppressing ringing artifacts.Consequently a better image with smooth splicing is obtained.The drawback of the sectioned restoration algorithm is overcomed..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3025 (2009)
Moving Object Detection from Dynamic Image Sequence Based on Stability Matrix
Hao Zhicheng, and Wu Chuan
To extract the moving target in video sequence fast and exactly,a self-adaptive background estimation technique was developed.Because of the different time-variability between background and foreground,a stability matrix was constructed,and according to its changes the background points could be distinguished from the To extract the moving target in video sequence fast and exactly,a self-adaptive background estimation technique was developed.Because of the different time-variability between background and foreground,a stability matrix was constructed,and according to its changes the background points could be distinguished from the foreground points.By setting two saturation values to the stability matrix,the algorithm could perceive the saltation of background automatically and update the background image quickly.Besides,in order to register the dynamic image sequences some local features were selected as templates,and projection matching technique was used to simplify the calculation and quicken the offset estimation.The experiment results show this algorithm has a high rate of convergence that only 10 frame are needed to get a stable background image,and the whole time is only 35 ms.So it meet the need of a processing ability of 25 frame/s in engineering..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3031 (2009)
A New Approach of Small and Dim Target Detection in Cloud Cluster Infrared Image Based on Classification
Li Xin, Zhao Yigong, and Chen Bing
A new method is proposed to detect infrared small and dim targets in cloud cluster image based on fuzzy classification.Firstly,according to the infrared imaging principles,dim and small targets in cloud cluster image can be divided into three classes,which are the edge class,the inner cloud and clear sky class,the targA new method is proposed to detect infrared small and dim targets in cloud cluster image based on fuzzy classification.Firstly,according to the infrared imaging principles,dim and small targets in cloud cluster image can be divided into three classes,which are the edge class,the inner cloud and clear sky class,the target class.By analyzing different classes,the classified models for each class are established.And then four-direction pixel feature vector is defined to describe different classes.Finally,based on the fuzzy classification theory,class correlation coefficient is defined to classify each pixel of the infrared image.Experimental results show that the proposed method can separate dim and small targets from the cluster in low signal-to-clutter ratio (SCR) infrared cloud images efficiently..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3036 (2009)
A Seal Imprint identifiction System Based on Embedded Structure
Liu Tiegen, He Jin, Deng Jijie, and Zhu Junchao
An embedded seal imprint identifiction system based on high speed digital signal processor (DSP) and field-programmable gate array (FPGA) is designed and fabricated.In recognition algorithms of the system,spatial coordinates of centers and radius of tested seals are calculated with a method based on flatness convolutioAn embedded seal imprint identifiction system based on high speed digital signal processor (DSP) and field-programmable gate array (FPGA) is designed and fabricated.In recognition algorithms of the system,spatial coordinates of centers and radius of tested seals are calculated with a method based on flatness convolution.The orientation between sample seal (SS) and model seal (MS) is calculated with the radius projection method,which calculates a group of one-dimensiond feature data instead of two-dimensiond.Improved Hausdorff distance is used to measure the similarity between seals,as seal quality being the control parameters.Artificial neural network is adopted in analyzing and estimation.In respect of hardware realization,System-on-a-programmable chip (SOPC) combining DSP serves as CPU of this verification system.Image preprocessor and controller are included in the SOPC system.As the master processor,DSP is applied to accomplish image feature detection and verification.General purpose interface (GPI) such as Ethernet interface,USB and RS232 is designed in the system.Experiment shows that seals can be effectively identified and the function of the small-size and low-cost verification system can be upgraded flexibly..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3043 (2009)
Tone Reproduction Method by a Local Model of Visual Adaptation Based on Sigmoid Function
Xiao Manjun, Chen Siying, Ni Guoqiang, and Wen Yan
In order to solve the dynamic range gap between image acquisition and display devices,tone reproduction algorithms are used to generate a visually similar mapping of input luminance to display luminance,which can be imported to realistic image rendition for ordinary images.The task is similar to visual adaptation proceIn order to solve the dynamic range gap between image acquisition and display devices,tone reproduction algorithms are used to generate a visually similar mapping of input luminance to display luminance,which can be imported to realistic image rendition for ordinary images.The task is similar to visual adaptation processes in human visual system.Under different adaptation levels,human eyes have different contrast sensitivity and adaptation mechanisms to cope with high dynamic range scenes,where both too bright and too dark regions contained.So a realistic image rendition method by a local model of visual adaptation is proposed in this paper.The S-shape nonlinear mapping relationship is simulated by parameters controlled Sigmoid function,and its adaptive compression curves are achieved corresponding to various lightness adaptation levels.The method effectively keeps the balance between the wholly tone and luminance and local contrast,and enhances the visibility in dark region and keeps the detail in too bright region at the same time.Subjective assessment with objective featured statistical values is applied in the paper,it′s approved that the method can effectively achieve high dynamic range compression,enhance image detail without artifacts,and it′s computationally efficient and easy to use..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3050 (2009)
Instrumentation, Measurement and Metrology
Research on High-Precision Acquisitive Method of Surface Coordinate Information Based on Parallel Confocal Microscopy
Yu Qing, Yu Xiaofen, and Bi Meihua
Parallel confocal microscopy,which can detect lots of measured points simultaneously,can provide better efficiency in measurement,but bring larger off-axis aberration into the system.The horizontal offset of off-axis facula cannot be eliminated by existing data processing method,so centre-proliferation method and opticParallel confocal microscopy,which can detect lots of measured points simultaneously,can provide better efficiency in measurement,but bring larger off-axis aberration into the system.The horizontal offset of off-axis facula cannot be eliminated by existing data processing method,so centre-proliferation method and optic-intensity restructuring method are brought up to obtain optic-intensity displacement curves.Experimental results show that the method of centre-proliferation and optic-intensity restructuring can remove horizontal offset of about 10 μm of off-axis facula.In contrast to exiting method,the system′s stability has been increased by 2 and 5 times by these two kinds of methods,which can fit the high-precision requirement in rapid measurement..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3057 (2009)
Projector Calibration Algorithm for the Structured Light Measurement Technique
Li Zhongwei, Shi Yusheng, Zhong Kai, and Wang Congjun
A projector model is described in details,and a simple and accurate projector calibration method is proposed.In this method,the projector can be viewed as an inverse camera,and a plane calibration board with circle marks is used to calibrate the projector.During the calibration processing,two series fringe patterns witA projector model is described in details,and a simple and accurate projector calibration method is proposed.In this method,the projector can be viewed as an inverse camera,and a plane calibration board with circle marks is used to calibrate the projector.During the calibration processing,two series fringe patterns with different directions are projected onto the calibration board to establish accurate projector image and camera image correspondence.Thereby,the projector calibration dataset can be generated.Then the projector can be calibrated using a well established camera calibration algorithm.The experiment results show that the projector calibration algorithm proposed in this work is easy to operate and precise.The calibration precision can achieve 0.312 pixel..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3061 (2009)
Target Detection Method of Focal Plane Array Search System
Qian Weixian, Guan Zhiqiang, Chen Qian, and Gu Guohua
In accordance with the features of the area infrared focal plane array (AFPA),an new focal plane array search system is introduced.The system′s innovation lies in that the AFPA′s rotation will increase the number of the target detection effective pixel,and this will increase the target detection signal to noise ratio (In accordance with the features of the area infrared focal plane array (AFPA),an new focal plane array search system is introduced.The system′s innovation lies in that the AFPA′s rotation will increase the number of the target detection effective pixel,and this will increase the target detection signal to noise ratio (SNR).Firstly,the parameters of focal plane array search system′s and it′s work process,then deduces the system point spread model are described and the imaging characteristics of the target is analyed.Secondly the target detection algorithm is described and analyzed,and the signal processing hardware architecture is introduced.Finally the experimental results show that the focal plane array search system has high target detection probability,and can detect dim target in the strong clutter enviroment..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3066 (2009)
A Study on the Low Energy X/γ-ray Spectral Response of CdZnTe Planar Detectors
Xu Yadong, Jie Wanqi, Zha Gangqiang, Gao Junning, Wang Tao, Fu li, and Paul Sellin
Three CdZnTe planar detectors,named CZT1,CZT2 and CZT3 respectively,were fabricated based on the as-grown CdZnTe wafers grown with different dopant conditions.The low energy X/γ-ray spectral responses of the detectors were obtained under various electrical field strengths at room temperature.The energy resolution of thThree CdZnTe planar detectors,named CZT1,CZT2 and CZT3 respectively,were fabricated based on the as-grown CdZnTe wafers grown with different dopant conditions.The low energy X/γ-ray spectral responses of the detectors were obtained under various electrical field strengths at room temperature.The energy resolution of the detectors was evaluated by combining the charge transport properties of the materials and the dopant behaviors.The deep level trapping centers of Cd2+i have been tentatively recognized as the electron trapping centers,hence deteriorating the resolution.Low In concentration doped CZT2 exhibits excellent X/γ-ray spectral resolution and charge transport properties,which implies a lower density of trapping centers in the crystal.In Al doped CZT3,however,a critically uncompleted charge carrier collection and in turn the reduced energy resolution is likely attributed to the scattering of the ionized aluminum interstitial Ali..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3072 (2009)
Extract Original Grating Information from Deformed Grating Pattern
Yang Chuping, Weng Jiawen, Zhao Jing, and Yang Yi
Based on fourier transform profilometry(FTP),a new method is proposed for extracting the fundamental frequency information of the original grating pattern from its deformed grating pattern and reconstructing the original grating pattern.Firstly,the functions of original grating pattern and reference plane are describedBased on fourier transform profilometry(FTP),a new method is proposed for extracting the fundamental frequency information of the original grating pattern from its deformed grating pattern and reconstructing the original grating pattern.Firstly,the functions of original grating pattern and reference plane are described,and the relation between original grating pattern and its deformed grating pattern is revealed.Then the spectrum distribution of the deformed grating pattern is analyzed by use of 1-D dilating Gabor transform,and the fundamental frequency information is distinguished and extracted from the spectrum.Finally,a full original grating pattern is reconstructed to realize 3-D shape measurement.Experimental results show the validity of the above method..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3078 (2009)
Modeling and Experiment of Testing Asphere by Annular Subaperture Stitching Interferometer
Wang Yuezhu, Tian Yi, Li Hongyu, and Ju Youlun
In order to obtain the whole aspheric lens′ surface information,measurement of aspheric optical components is implemented by using spheric wave interferometry.Problems of precise location and removing relative rotation are resolved by the Givens transform of markers′ position.Each subaperture′s data is processed by theIn order to obtain the whole aspheric lens′ surface information,measurement of aspheric optical components is implemented by using spheric wave interferometry.Problems of precise location and removing relative rotation are resolved by the Givens transform of markers′ position.Each subaperture′s data is processed by the best fitting wave front which is the solution of the least object function value.Global optimization stitching model is established.A parabolic mirror of 150 mm in outer diameter,100 mm in inner diameter was used in three annular subapertures stitching experiment,the obtained root mean square (RMS) is 0.053 λ.Compared with full caliber interference measurement results obtained by compensator method,ΔWrms=0.052 λ,the relative error of RMS is 1.92%.Experimental results indicate that the approach reduces the requirements of high-precision rail in traditional annular subaperture stitching interference measurement..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3082 (2009)
Lasers and Laser Optics
The Influence of Wave-Front-Distorted Pump Pulse on the Beam Quality of OPA Front-End System of the Petawatt Laser
Wang Yanhai, Pan Xue, Li Xuechun, and Lin Zunqi
The influence of wave-front-distorted pump pulse on the beam quality of the amplified signal pulse in the non-collinear optical parametric amplification (OPA) is numerically simulated.The results indicate that diffraction and walk-off effects degrade the signal beam quality via different physical process when the wave-The influence of wave-front-distorted pump pulse on the beam quality of the amplified signal pulse in the non-collinear optical parametric amplification (OPA) is numerically simulated.The results indicate that diffraction and walk-off effects degrade the signal beam quality via different physical process when the wave-front of pump laser pulse is distorted seriously.Walk-off effect is the main factor to degrade the beam quality of the signal pulse when OPA works in linear regime.The sunken-center of spatial beam shapes induced by oversaturation of OPA play the dominant role in the degradation of beam quality when OPA works in oversaturated regime..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3088 (2009)
50 fs Pulse Generation from All-Fiber Stretched-Pulse Laser
Deng Dinghuan, Zhan Li, Gu Zhaochang, Gu Yi, and Xia Yuxing
Using the nonlinear polarization rotation mode-locking and cavity dispersion management,we report the direct generation of 50-fs pulses from a stretched-pulse Er-doped ring laser with all-fiber construction.The average output power was 56.4 mW under a 330 mW pump power with a repetition rate of 37.8 MHz,which had relatUsing the nonlinear polarization rotation mode-locking and cavity dispersion management,we report the direct generation of 50-fs pulses from a stretched-pulse Er-doped ring laser with all-fiber construction.The average output power was 56.4 mW under a 330 mW pump power with a repetition rate of 37.8 MHz,which had relatively high conversion efficiency of 17% for all-fiber construction.The pulse energy was greatly improved to 1.5 nJ.The smooth output spectrum without any side lobe showed the laser worked on the single-pulse operation..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3094 (2009)
leetro-Optic Q-Switched of Double LDA Alternate Symmetric Side-Pumped Nd:YAG Laser
Chen Xinyu, Jin Guangyong, Yu Yongji, and Liang Zhu
Double laser diode array (LDA) alternate symmetric side-pumped Nd:YAG laser is developed.The 1064 nm dynamic-laser output has been obtained by electro-optic (E-O) Q-switch.The perfect matching of gain field inside of the crystal and fundamental mode of cavity can be made by this structure,and high beam quality,high powDouble laser diode array (LDA) alternate symmetric side-pumped Nd:YAG laser is developed.The 1064 nm dynamic-laser output has been obtained by electro-optic (E-O) Q-switch.The perfect matching of gain field inside of the crystal and fundamental mode of cavity can be made by this structure,and high beam quality,high power output and high extraction efficiency can be easily obtained.The pumping source is the LD array which the peak power of one module is 100 W,and a direct close-pumping configuration and KD*P crystasal as E-O Q-switch are used for the laser in the experiment chooses.By using the ABCD propagation law of Gaussian beams,the stability-area of resonant cavity is calculated and the more reasonable parameters of resonant cavity are offered.When the repetition frequency is 20 Hz and the pumping energy is 1200 mJ,the 1064 nm dynamic-laser output with 151 mJ output energy and 8.48 ns pulse width is obtained,and the conversion efficiency of light-light is 12.6%..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3098 (2009)
Passively Mode-Locked Side-Pumped Nd:YAG Laser with SESAM
Li Xiao, Wang yongang, Zhang Shiqiang, Wang Xiaobo, and Xu Xiaojun
Recently,semiconductor saturable absorbers mirror (SESAM) have become the important components in the compact mode-locking solid-state lasers.We designed a side-pumped folded cavity Nd:YAG solid laser mode-locking with SESAM and get the highest average output power about 9.45 W.The single pulse has about 141 nJ energy Recently,semiconductor saturable absorbers mirror (SESAM) have become the important components in the compact mode-locking solid-state lasers.We designed a side-pumped folded cavity Nd:YAG solid laser mode-locking with SESAM and get the highest average output power about 9.45 W.The single pulse has about 141 nJ energy and 71 MHz repetitionrate.With exactly measurement about the thermal focal length,special cavity can be designed to control the mode radius.Although the laser was pumped by high power laser diode (LD) (over hundreds watts),but it still has very well beam quality (nearly the diffraction-limited beam).From this work ,it get closer towards the high power mode-locked solid laser..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3103 (2009)
Spectral Selection in He-Ne Laser by Internal F-P Etalon
Liang Jing, Long Xingwu, Zhang Bin, and Jin Shilong
In He-Ne laser,since the 633 nm line has higher gain than the other 5 lines around its band,as far as the mode competition is concerned,it′s hard for the line with low gain (such as the 629 nm line) to emit.A spectral selection method in He-Ne laser by Fabry-Perot (F-P) etalon is discussed in this paper.By choosing theIn He-Ne laser,since the 633 nm line has higher gain than the other 5 lines around its band,as far as the mode competition is concerned,it′s hard for the line with low gain (such as the 629 nm line) to emit.A spectral selection method in He-Ne laser by Fabry-Perot (F-P) etalon is discussed in this paper.By choosing the proper length and reflectivity of the F-P etalon,the line with high gain can be restrained while keep the weak one untouched.In this way,the line with weak gain can emit.The transmitting properties of F-P etalon in cavity are calculaled by Gaussian beam theory..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3108 (2009)
Numerical Simulation of Temperature Field of Coaxial Powder Flow in Laser Cladding
Yang Xichen, Li Li, and Zhang Ye
In laser coaxial cladding,laser casing qualities are directly affected by temperature field of powder flow for the interaction between laser and powers.According to the model of non-premixed combustion,regarding laser beam as continuity medium phase and powder as disperse medium phase,the conservation equations of massIn laser coaxial cladding,laser casing qualities are directly affected by temperature field of powder flow for the interaction between laser and powers.According to the model of non-premixed combustion,regarding laser beam as continuity medium phase and powder as disperse medium phase,the conservation equations of mass,momentum and energy are established in laser and powder flow.Computer simulations of temperature field in different parameters are finished using Fluent software.Some effects of laser cladding parameters on temperature distribution such as laser power and powder flow velocity are discussed.Temperature field distribution in the powder flow is measured by CCD camera.It is shown that simulation and experimental results agree well,numerical simulation of temperature field in powder flow is important for laser cladding..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3114 (2009)
Femtosecond Erbium-Doped Fiber Laser Mode-Locked with a High Modulation Depth SESAM
Cai Yue, Yang Weijian, Zhou Chun, Zhang Guangxiao, Zhang Meng, and Zhang Zhigang
We fabricated a 20% modulation depth semiconductor saturable absorber mirror on a metal/dielectric mirror base,for ease of the growth restrictions.Using such a saturable absorber mirror,we obtained self-starting mode-locking in a ring erbium-doped fiber laser.The output pulse width was 170 fs and the repetition rate waWe fabricated a 20% modulation depth semiconductor saturable absorber mirror on a metal/dielectric mirror base,for ease of the growth restrictions.Using such a saturable absorber mirror,we obtained self-starting mode-locking in a ring erbium-doped fiber laser.The output pulse width was 170 fs and the repetition rate was 25.6 MHz..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3121 (2009)
Machine Vision
An Accurate Calibration Method for Line Structured Light Vision Sensor
Liu Zhen, Zhang Guangjun, Wei Zhenzhong, and Jiang Jie
A calibration method for line structured light vision sensor that does not require extraction of control points in the light plane is proposed to solve the calibration problem of line structured light vision sensor.The planar target is placed in front of the vision sensor several times.The Plücker matrix of light A calibration method for line structured light vision sensor that does not require extraction of control points in the light plane is proposed to solve the calibration problem of line structured light vision sensor.The planar target is placed in front of the vision sensor several times.The Plücker matrix of light strip on the target plane is computed.The equation of the light plane in the camera coordinate frame can be solved by combining the Plücker matrixs of the light stripe on the target plane at different positions.The maximum likelihood estimation of the light plane equation is obtained through nonlinear optimization.The proposed method is robust and accurate,because all of the light stripe image points are used to determine the equation of the light plane.Experimental results show that,compared with that of existing calibration methods,the calibration accuracy of the proposed method improves about 30%..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3124 (2009)
An Extended Orthogonal Iteration Algorithm for Pose Estimation from Point and Line Segment Correspondences
Xu Yunxi, Jiang Yunliang, and Chen Fang
The orthogonal iteration algorithm is fast and globally convergent pose estimation based on points.And it is a one of the state-of-art real-time pose estimation algorithms.A new method that we express the uncertainty of sensed line segment using object-space line segment error is introduced.An extended orthogonal iteraThe orthogonal iteration algorithm is fast and globally convergent pose estimation based on points.And it is a one of the state-of-art real-time pose estimation algorithms.A new method that we express the uncertainty of sensed line segment using object-space line segment error is introduced.An extended orthogonal iteration algorithm is proposed.And it can use point and line segment feature simultaneously.Firsly we formulate coplanarity equation of point data into the same mathematics format with collinearity equation of point data and translate object-space coplanarity error of line segment into coplanarity error of point.Then the sum of object-space collinearity error of point and coplanarity error of line segment is used as error function.Finally,an iterative algorithm is developed to minimize the error function.The experiment results show that extended orthogonal iteration algorithm is effective and accurate.The algorithm can give more accurate,stable result and increase the noise resistance performance compared with the orthogonal iteration algorithm..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3129 (2009)
Cameras Calibration Based on One-Dimensional Reference Object and Improved Evolutionary Strategy
Zhang Lingfei, Chen Gang, Ye Dong, and Che Rensheng
To calibrate the intrinsic and extrinsic parameters of cameras in motion parameters photoelectric measurement system,a novel approach based on improved evolutionary strategy and surveying a rigid one-dimensional object carrying three markers on its middle and extremities moved inside the working volume,which does not rTo calibrate the intrinsic and extrinsic parameters of cameras in motion parameters photoelectric measurement system,a novel approach based on improved evolutionary strategy and surveying a rigid one-dimensional object carrying three markers on its middle and extremities moved inside the working volume,which does not require other complex calibration equipments,was proposed in this paper.Firstly,it is assumed that the principal point is located at a certain location around the image plane center.Then the focal length of cameras,the rotation matrix,translation vector and the scale factor are obtained.Finally,the estimation of intrinsic and extrinsic parameters of cameras is formulated as a nonlinear minimization problem of a cost function.The simulated annealing evolutionary strategy algorithm was improved by introducing the self-improved factor and the Euclidean distance between individual.Consequently the global convergence performance of the search algorithm of this method was mended and accelerated.By introducing the evolutionary strategy,the new method can find out the intrinsic and extrinsic parameters all together,and need not constrain the movement of the one-dimensional object in comparison with traditional methods..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3136 (2009)
Materials
The Effects of Yb3+/Tm3+ / Ho3+ Doping Concentration on 2 μm Wavelength Luminscence in Germanium Glasses
Yu Chunlei, He Dongbing, Wang Guonian, Hu Lili, and Zhang Junjie
In order to study on the feasibility of achieving 2 μm laser by using Yb3+/Tm3+/Ho3+ codoping in germanium glass,the effects of doping concentration of three rare-earth ion on the nearly 2 μm luminscence were researched,so optimized doping concentration can be acquired.The results show that when the doping mole fractioIn order to study on the feasibility of achieving 2 μm laser by using Yb3+/Tm3+/Ho3+ codoping in germanium glass,the effects of doping concentration of three rare-earth ion on the nearly 2 μm luminscence were researched,so optimized doping concentration can be acquired.The results show that when the doping mole fraction of TmF3 is 1%,the 2 μm luminscence of Ho3+ increases with doping concentration of Yb3 + ions.However,as the doping mole fraction of TmF3 is increased to 3%,the 2 μm luminscence intensity of Ho3+ is reduced with increasing doping concentration of Yb3 +.The near 2 μm luminscence of Tm3+ can be raised by increasing doping concentration of Yb3+ ions and it is more apparent at high doping concentration of Tm3+ ions,which could weaken the luminscence of Ho3+ relatively.On the whole,the 2 μm luminscence of Ho3+ is significantly effected by the doping concentration ratio of Tm3＋/Ho3+.When the three doped samples were pumped by 980 nm LD,both the high doping concentration of Tm3+ ions and low doping concentration of Ho3+ ions can lead to the reduction of 2 μm luminscence intensity of Ho3+..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3143 (2009)
Study on the Dispersion of Birefringent Indexes of Mica Crystal
Kong Fanmei, Li Guohua, Li Chunhong, and Du Honggang
The inherent discrepancy of birefingent dispersion relations of mica crystal has an unfavourable effect on designing wave-plate.A way of the polarization interference spectrum to study the dispersion of birefringent indexes of mica crystal is presented.The polarization interference spectrum of mica wave-plates are measThe inherent discrepancy of birefingent dispersion relations of mica crystal has an unfavourable effect on designing wave-plate.A way of the polarization interference spectrum to study the dispersion of birefringent indexes of mica crystal is presented.The polarization interference spectrum of mica wave-plates are measured with spectrophotometer.Then through accurate judgment extreme points of the polarization interference spectrum,the maximal birefringent index at the extreme points can be calculated exactly and the dispersion curve is obtained from visible spectral band to ultraviolet spectral band.At last,expressions of the birefingent dispersion at any wavelength for mica crystal can be achieved through polynomial fitting data processing.This paper offers a accurate and simple method for measuring the birefringent index of mica crystal at any wavelength and temperature,also offers parameter choice basis for correctly using and designing crystal mica devices..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3148 (2009)
Study on the Electronic Structure and Optical Properties of Ru2Si3 Epitaxial on Si(001)
Cui Dongmeng, Xie Quan, Chen Qian, Zhao Fengjuan, and Li Xuzhen
We calculated the electronic structure and optical properties of semiconductor material Ru2Si3 epitaxial on Si (001) that the epitaxial relation is Ru2Si3 (100)//Si(001) with Ru2Si3 [010]//Si[110] by using the pseudo-potentials plane-wave method based on first-principles methods.As shown by the calculated results,when We calculated the electronic structure and optical properties of semiconductor material Ru2Si3 epitaxial on Si (001) that the epitaxial relation is Ru2Si3 (100)//Si(001) with Ru2Si3 [010]//Si[110] by using the pseudo-potentials plane-wave method based on first-principles methods.As shown by the calculated results,when the lattice parameter α is between 1.087 nm with 1.099 nm,the band gap of orthorhombic Ru2Si3 increases with the increase of α.The system is in the stable conduction as well as Ru2Si3 is a direct semiconductor with the band gap of 0.773 eV when the lattice parameter is 1.093 nm.The valence bands of Ru2Si3 are mainly composed of Si 3p,3s and Ru 4d,the conduction bands are mainly composed of Ru 4d and Si 3p.The calculated real part and imaginary part of dielectric function shows that the trend of change is similar on the whole between the epitaxial stable conditions and its neighbouring points.However,the curves of epitaxial Ru2Si3 drift toward low energy and the number of dielectric function peak decreases as well as the intensity bocomes strong obviously..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3152 (2009)
High Performance Large Aperture Paramagnetic Faraday Rotatory Glass
Jiang Yasi, Zhou Peiming, Wang Biao, and Hu Lili
Faraday rotatory glass has been used for modulating,deflecting of laser,optical switch and isolator.The main property of Faraday rotatory glass is the Verdet constant.Faraday rotatory glass containing high paramagnetic ion concentration is of the large Verdet constant,transparency in the visible region of light.TerbiumFaraday rotatory glass has been used for modulating,deflecting of laser,optical switch and isolator.The main property of Faraday rotatory glass is the Verdet constant.Faraday rotatory glass containing high paramagnetic ion concentration is of the large Verdet constant,transparency in the visible region of light.Terbium ion with larger magnetic moment and lower f-d transition energy gap should possess the large Verdet constant.Based on the Tb2O3-B2O3-Al2O3-SiO2 system with high terbium oxide content,the glass formation region was determined and a linear relation between Tb3+ concentration and the Verdet constant was established.Faraday rotatory glass series of TG20,TG28 and TG32 with the Verdet constant of 75.1-116.4 rad/(T·m) was developed by modifying the glass composition to avoid devitrification.A melting furnace of 10 liters platinum crucible,forming apparatus and fine annealing skin were built up to produce 30 cm aperture Faraday rotatory glass.The glass is provided with an optical absorption coefficient of less than 0.008 cm-1 at 1054 nm,a laser damage threshold of larger than 8 J/cm2 at 1 ns pulse width,a transmitted wavefront distortion of less than λ/5 at 632 nm.The glass has been used for high power systems of LLNL in US,upgraded “Shenguang Ⅱ” in China,Vulcan laser system of Ruthorford Lab.In UK and Luli Laser System of CNRS,CEA in France..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3157 (2009)
Medical Optics and Biotechnology
Experimental Research on Fluorescence Spectra of Melamine Solution
Han Caiqin, Liu Ying, Zhao Wenyan, Luo Xiaosen, and Ni Xiaowu
The fluorescence spectra of melamine-water solution and milk powder-water solution mixed with melamine excited by UV-light were studied experimentally.The emission mechanism and the spectral characteristic were discussed,and the fluorescence spectra were analyzed and calculated by ordinate ratio transformation.The resuThe fluorescence spectra of melamine-water solution and milk powder-water solution mixed with melamine excited by UV-light were studied experimentally.The emission mechanism and the spectral characteristic were discussed,and the fluorescence spectra were analyzed and calculated by ordinate ratio transformation.The result shows that the melamine-water solution exhibits an obvious fluorescence peak nearby 350 nm and 370 nm with the optimal excitation wavelength of 240 nm.Compared with milk powder-water solution,the fluorescence peak location of milk powder-water solution mixed with melamine,excited by UV-light with same wavelength,changes from 328 nm to 350 nm.The other peak locations are basically changeless,and the relative fluorescence intensity of 370 nm is the maximum one..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3163 (2009)
Three-Dimensional Vector Velocity Measurement in Optical Doppler Tomography
Meng Jie, Ding Zhihua, and Zhu Ying
Optical Doppler tomography (ODT) is a high-resolved and non-invasive biomedical imaging technique,which can obtain tissue structure and blood flow velocity at the same time.A novel phase-resolved ODT method to measure three-dimensional vector velocity is presented.After inserting the designed narrowband phase plate betOptical Doppler tomography (ODT) is a high-resolved and non-invasive biomedical imaging technique,which can obtain tissue structure and blood flow velocity at the same time.A novel phase-resolved ODT method to measure three-dimensional vector velocity is presented.After inserting the designed narrowband phase plate between the collimator and focusing lens of the sample arm,three different phase retardations are formed.By calculating the Doppler shift and the Doppler bandwidth relative to the three phase retardations,three-dimensional vector velocity distribution of the solution inside the capillary is obtained.Several experiments of polystyrene solution with different angle setup and variational flow velocity are conducted,and the results demonstrate the feasibility of this method to measure three-dimensional vector velocity..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3168 (2009)
Finite Element Analysis for Temperature Characteristics of Normal and Embedded Tumor Female Breast
Yang Hongqin, Xu Aqing, Wang Yuhua, Xie Shusen, Ye Zhen, and Su Yiming
Based on the breast anatomical structure and physiological characteristics, a three-dimensional thermal model for normal and embedded tumor breast which considered the metabolic heat generation, blood perfusion and heat exchange between vascular and breast was established. Finite element method was used to solve this mBased on the breast anatomical structure and physiological characteristics, a three-dimensional thermal model for normal and embedded tumor breast which considered the metabolic heat generation, blood perfusion and heat exchange between vascular and breast was established. Finite element method was used to solve this model for numerically simulating the temperature distribution of breast, and then the effects of various factors, such as blood perfusion, metabolic heat generation, the size, location and numbers of breast tumor, air convection coefficient and environmental temperature on the temperature distribution of breast were discussed. The results show that the temperature profiles of breast could be significantly affected by the metabolic heat generation, blood perfusion, tumor size, tumor position and numbers, while the surface thermal expression of embedded tumor breast could be influenced by the air flow and environmental temperature. This study results may guide the experiment of breast thermograms and provide important reference for its qualitative analysis..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3173 (2009)
Optical Design and Fabrication
Process-Based Design of Continuous Phase Plates
Wen Shenglin, Xu Qiao, Ma Ping, Yang Chunlin, Zhou Lishu, and Yan Hao
A theoretical design model for continuous phase plates (CPP) used in inertial confinement fusion is built to improve the focus beam quality and reduce the difficulty of CPP′s fabrication.Moreover,the traditional G-S algorithm is modified through choosing continuous initial phase,phase unwrapping,phase filtering and conA theoretical design model for continuous phase plates (CPP) used in inertial confinement fusion is built to improve the focus beam quality and reduce the difficulty of CPP′s fabrication.Moreover,the traditional G-S algorithm is modified through choosing continuous initial phase,phase unwrapping,phase filtering and controlling the frequency spectrum of focal spot.The operational characteristic and the focal spot′s performance caused by the CPP designed by traditional G-S algorithm and modified G-S algorithm are analyzed comparatively.The surface designed by the modified method is smoother than the traditional G-S algorithm,and the root mean square (RMS) and capacity usage ratio of the focal spot caused by modified G-S algorithm are 16.9% and 98.6% respectively,which are all better than the traditional method′s 62.8% and 98.0%.The 10-100 μm modulations of focal spot are suppressed very well.It shows that the CPP designed by the modified method meets the process restriction and physical specifications very well..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3179 (2009)
Design of Apochromatism Objective Lens of Aerial Camera Based on Large Frame Array CCD
Li Yuyao, Tang Yong, Lin Zhaoheng, and Li Ning
To meet the requirement for simple structure and high-resolution,a method for correcting secondary spectrum of large frame array CCD aerial camera′s objective lens with long focal length and wide band based on wave aberration method is proposed.The principle of secondary spectrum is introduced and the equations of desiTo meet the requirement for simple structure and high-resolution,a method for correcting secondary spectrum of large frame array CCD aerial camera′s objective lens with long focal length and wide band based on wave aberration method is proposed.The principle of secondary spectrum is introduced and the equations of designing apochromatism objective lens based on wave aberration are presented.The apochromatism objective lens of aerial camera is designed by common optical materials.Objective′ focal length is 400 mm,relative aperture is F/4,and work waveband is 420-850 nm.The figures of optical system,longitudinal aberration and modulation transfer function (MTF) are given.Designing results show that the MTF of every field above 0.75 in 60 lp/mm,and satisfy the requirements of imaging for large frame array CCD whose effective size is 36 mm×48 mm..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3183 (2009)
Research on Meridian Lines Design for Progressive Addition Lenses
Wu Quanying, Qian Lin, Chen Hao, Wang Yuanyuan, and Yu Jingchi
The construction of progressive addition lenses is introduced,and the designing idea of lenses is also illustrated.The principle of designing meridional power laws for progressive addition lenses is expounded based on polynomial,and the criterion of designing meridional power laws is given out.On the basis of designingThe construction of progressive addition lenses is introduced,and the designing idea of lenses is also illustrated.The principle of designing meridional power laws for progressive addition lenses is expounded based on polynomial,and the criterion of designing meridional power laws is given out.On the basis of designing meridional power laws,the isopower contours are designed in order to determine the surfaces of progressive addition lenses.The mean surface power and the constant surface astigmatism are calculated.Three kinds of progressive addition lenses which are designed based on different meridional power laws are compared,and the lenses are manufactured and tested.It is shown that designing meridional power law is an important aspect of designing progressive addition lenses.There is much difference of the surface power,the surface astigmatism and the distortion corresponding to different meridional power laws.The rules of meridional power laws are given out to satisfy with individual demands according to the practical design and the testing results of progressive addition lenses..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3186 (2009)
Optical Devices
Axial Focusing Characteristics of Low F-Number Diffractive Optical Elements with Continuous Relief Fabricated by Laser Direct Writing
Shan Mingguang, Zhong Zhi, Guo Lili, and Zhi Pei
In order to study the effect of convolution effect and fabrication errors on the axial focusing characteristics of low F-number diffractive optical elements (DOE) with continuous relief fabricated by laser direct writing,a theoretical model is established using Rayleigh-Sommerfeld diffraction theory to describe the infIn order to study the effect of convolution effect and fabrication errors on the axial focusing characteristics of low F-number diffractive optical elements (DOE) with continuous relief fabricated by laser direct writing,a theoretical model is established using Rayleigh-Sommerfeld diffraction theory to describe the influence of the structure parameters,the diameter of the writing spot,the interscan distance and the fabrication errors on the diffraction focusing characteristics of low F-number DOE with continuous relief,and continuous-relief DOE with a design wavelength of 441.6 nm,a F-number of 4 and a phase depth factor of 3 are fabricated and measured.The good agreement between theoretical and experimental results verifies the validity of the diffraction model established..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3192 (2009)
Algorithm of Measuring Rate Biased Laser Gyro Static Angle Rate Based on Moving Average
Zhan Dejun, Qin Shiqiao, Wang Xingshu, and Zhang Baodong
Improving measuring accuracy of rate biased laser gyro angle rate is important to its application field.The quantization error is found important influence to laser by analyzing random drift of rate biased laser gyro,then a new static angle rate algorithm based on moving average theory is presented,which is also analyzImproving measuring accuracy of rate biased laser gyro angle rate is important to its application field.The quantization error is found important influence to laser by analyzing random drift of rate biased laser gyro,then a new static angle rate algorithm based on moving average theory is presented,which is also analyzed and simulated.The results shows that with properly grouping parameter selection,the influence of quantization error on rate biased laser gyro angle rate is reduced prominently,and the validity of the algorithm is also proved experimentally.The algorithm can be used in other situation,in which quantization reduction is significant..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3197 (2009)
Magnetic Sensitivity and Optimal Operating Point of Four-Frequency Differential Laser Gyroscope
Wang Zhiguo, Long Xingwu, Wang Fei, and Yuan Jie
In order to reduce magnetic sensitivity of four-frequency differential laser gyro (DILAG),effect of operating point on magnetic sensitivity was investigated.According to theoretical analysis,magnetic sensitivity arises mainly from unequal relative scale factor corrections of left and right circularly polarized gyros.ThIn order to reduce magnetic sensitivity of four-frequency differential laser gyro (DILAG),effect of operating point on magnetic sensitivity was investigated.According to theoretical analysis,magnetic sensitivity arises mainly from unequal relative scale factor corrections of left and right circularly polarized gyros.The DILAG,however,is insensitive to magnetic field when operating at the optimal point.Axial magnetic filed was produced by winding coil around gain tube,and operating point was changed by adjusting voltage of piezoelectric transducer affixed to cavity mirror in our experiment.As a result,the curve of magnetic sensitivity versus operating point was obtained.The results showed that DILAG was insensitive to magnetic field at the optimal operating point,which uniquely existed within operating area.Environmental disturbance would be reduced when DILAG was operating at the optimal point.This helped to improve DILAG performance.The conventional frequency stabilization method using light intensity comparison should be changed so as to make sure DILAG operating at the optimal point..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3202 (2009)
Development of an Imaging Velocity Interferometer System for Any Reflector
Peng Xiaoshi, Wang Feng, Liu Shenye, and Jiang Xiaohua
Imaging velocity interferometer system for any reflector (VISAR) is an important diagnostic tool for a variety of experiments involving laser-driven shock-wave propagation,including pulse shaping tool experiments for inertial confinement fusion research,high-pressure state equation experiments and materials characterizImaging velocity interferometer system for any reflector (VISAR) is an important diagnostic tool for a variety of experiments involving laser-driven shock-wave propagation,including pulse shaping tool experiments for inertial confinement fusion research,high-pressure state equation experiments and materials characterization experiments.On the basis of conventional VISAR,an imaging VISAR has been implemented at the shenguang-Ⅲ prototype.Making use of the imaging VISAR,velocity of free surface and shock wave traveling through transparent media can be measured.The key points in designing an imaging VISAR are described in detail.Analyzing and testing the capability of the imaging VISAR indicate that the instrumen′s temporal resolution is 30 ps,spatial resolution about 10 μm,and velocity can be measured over the range from 6-45 km/s..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3207 (2009)
Study on Curing Control and Focal Spot Measurement of Aspherical Liquid Microlens
Zhan Zhenxian, Wang Keyi, Yao Haitao, and Ding Zhizhong
Aspherical liquid microlens of ultra-violet(UV) curable polymer was fabricated by using electrostatic field and real-time measurement.It was investigated that the surface profile and focal spot of the aspherical liquid lens had distortions while UV curing.The surface profiles and the focal spots before and after curingAspherical liquid microlens of ultra-violet(UV) curable polymer was fabricated by using electrostatic field and real-time measurement.It was investigated that the surface profile and focal spot of the aspherical liquid lens had distortions while UV curing.The surface profiles and the focal spots before and after curing were compared.The reasons why distortion happened,its influence on lens′s optical quality and how it can be solved were all discussed.Spot probe scanning microscope with 50 nm resolution was employed to accurately measure the focal spots of the aspherical microlens.The spots at different axis positions and focal spot with 0.384 μm diameter were achieved.The point spread function and optical transfer function of the aspherical microlens were calculated,and the actual imaging photographs were provided.So the imaging ability of the aspherical microlens can be evaluated and it′s important for perfecting the lens fabricating technology..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3212 (2009)
Physical Optics
Scattering From an Elliptic Cylinder Irradiated By an Electromagnetic Wave With Arbitrary Direction and Polarization
Li Yingle, Wang Mingjun, and Tang Gaofeng
Based the three dimensional scales transformation of E.M.theory,the analytical expression of scattering field from a conductor elliptic cylinder is presented,as the electromagnetic wave propagating vertical to the axis of an elliptic cylinder with arbitrary incident angle and polarization.The obtained result is in agreBased the three dimensional scales transformation of E.M.theory,the analytical expression of scattering field from a conductor elliptic cylinder is presented,as the electromagnetic wave propagating vertical to the axis of an elliptic cylinder with arbitrary incident angle and polarization.The obtained result is in agreement with that in the reference when we use the analytical expression to calculate the scattering field from a cylinder.The varying of scattering width of this elliptic cylinder with the incident azimuth angle,frequency and sizes of the target is simulated.It is shown that the vertical size of the elliptic cylinder effects greatly the scattering field when we observe it in the direction perpendicular to the direction of incident wave.The scattering field is strong as the polarization direction of incident wave parallels to the axis of the elliptic cylinder.The algorithm used in the article can be able used to investigate the scattering characteristic of other elliptic cylinders.The obtained result offers a theoretical foundation for the practical applications such as electromagnetic remote sensing of target′s size and shape..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3217 (2009)
Characteristics of Plane Waves′ Rainbow Scattered by Infinite Inhomogeneous Cylinder
Jiang Huifen, Li Daoyong, and Han Xiang′e
Characteristics of scattering intensity distributions of the first and second order rainbows of graded-index polymer optical fiber (GI-POF) are studied by Lorenz-Mie theory and Debye series.By using low pass filter,band filter and inverse fast Fourie transform to the interference intensity distributions of different orCharacteristics of scattering intensity distributions of the first and second order rainbows of graded-index polymer optical fiber (GI-POF) are studied by Lorenz-Mie theory and Debye series.By using low pass filter,band filter and inverse fast Fourie transform to the interference intensity distributions of different order rainbows,the contributions of each order can to recogniyed.The result conforms to the simulations of Debye series well.Twin first order rainbows are discussed,and the corresponding scattering intensity distributions are simulated by Lorenz-Mie theory and Debye series..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3222 (2009)
Scattering
Analysis of Scattering Properties for Magnetic Absorbing Particles at the Radar Wave Band
Yang Jingtao, Cai Xiaoshu, and Shen Jianqi
This paper analyzes the light-scattering properties of the widely-used nanometer or micrometer absorbing magnetic particles at radar wave band based on Mie scattering theory.the effects of the permeability,refractive index and particle sizes on the scattering characteristics are analyzed.The scattering characteristics This paper analyzes the light-scattering properties of the widely-used nanometer or micrometer absorbing magnetic particles at radar wave band based on Mie scattering theory.the effects of the permeability,refractive index and particle sizes on the scattering characteristics are analyzed.The scattering characteristics including scattering intensity,absorption coefficient,scattering coefficient and etc.by magnetic and non-magnetic particles are also compared analytically as well as those by absorbent and transparent particles.Numerical results indicate that the permeability variation has influences on the scattering characteristics such as scattering intensity and absorption property.It is found that the absorption ability increases and back scattering characteristic decreases towards high permeability while its effect on the particles scattering characteristics is restricted simultaneously by the complex refractive index..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3227 (2009)
Thin Films
Photoelectric Effects of ZnO/P-Si Heterojunction
Qi Hongxia, and Chen Chuanxiang
ZnO/P-Si heterojunctions are fabricated by pulsed laser deposition of ZnO films on P-Si substrates.The substrate temperatures of 400 ℃,500 ℃,550 ℃ and 600 ℃ are taken for the ZnO film deposition.All the heterojunctions show typical rectifying behaviors and the reverse dark current increases with the substrate temperatuZnO/P-Si heterojunctions are fabricated by pulsed laser deposition of ZnO films on P-Si substrates.The substrate temperatures of 400 ℃,500 ℃,550 ℃ and 600 ℃ are taken for the ZnO film deposition.All the heterojunctions show typical rectifying behaviors and the reverse dark current increases with the substrate temperature.The sample prepared at 550 ℃ shows the best photoelectric effects.There are different I-V characteristics as the ZnO/P-Si heterojunction is exposed to visible and ultraviolet (UV) photons.The photocurrent increases rapidly in the initial several voltages,but slowly beyond a certain reverse bias voltage.When the sample is illuminated by UV photon,the photocurrents show a gradual increase with the bias.According to the transmittance spectra of the ZnO films,it is thought that the electron-hole pairs are induced in the different depletion of the heterojunction for the visible and UV photons..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3232 (2009)
Properties of Germanium Thin Film and Its Application in Photon Counting Imaging System
Zhao Feifei, Zhao Baosheng, Zhang Xinghua, Li Wei, Zou Wei, Sai Xiaofeng, and Wei Yonglin
The Ge thin films applied in photon counting imaging system based on Ge induction readout were fabricated by electron beam evaporation.The structures of Ge thin films deposited on ceramic and quartz glass substrates and influences of technical parameters on resistance were studied.The X-ray diffraction (XRD) analysis oThe Ge thin films applied in photon counting imaging system based on Ge induction readout were fabricated by electron beam evaporation.The structures of Ge thin films deposited on ceramic and quartz glass substrates and influences of technical parameters on resistance were studied.The X-ray diffraction (XRD) analysis of thin films deposited on the two substrates shows that the thin films deposiited on two kinds of substrates both have cubic amorphous Ge structure.The field emission scanning electron microscopy (FESEM) images indicate that the film deposited on quartz glass is more compact and smooth than that deposited on the ceramic substrate.If the film on the ceramic substrate is too thin,the film is discontinuous,which induces the high resistance.The resistance can be controlled by annealing,depositing rate,or thickness of film.The performance of the system,which adopted Ge layers with different resistance,was studied.These results suggest that resistance of the charge induced layer influences spatial resolution less than the counting rate..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 11, 3236 (2009)
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