Contents
2009
Volume: 29 Issue 10
54 Article(s)
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Atmospheric Optics and Oceanic Optics
Application of Vehicle-Borne Passive Differential Optical Absorption Spectroscopy for Urban Traffic Air Pollution Monitoring
Wang Shanshan, Zhou Bin, Ye Qing, and Qi Feng
A mobile vehicle-borne monitoring system,passive differential optical absorption spectroscopy which is based on natural light sources,has been explored and applied successfully in the experiment of traffic air pollution monitoring in Hefei. The system uses passive zenith-sky scattered light differeential optical absorpA mobile vehicle-borne monitoring system,passive differential optical absorption spectroscopy which is based on natural light sources,has been explored and applied successfully in the experiment of traffic air pollution monitoring in Hefei. The system uses passive zenith-sky scattered light differeential optical absorption spectroscopy (DOAS) to sample and analysis the air on the top of the road,combining with real-time GPS receiver to acquire latitude and longitude coordinates. According to the GPS positioning coordinates in the Hefei traffic map and the NO2 vertical column density retrieved from the spectrum,a overall air quality map will be produced. The difference of NO2 vertical column density between the monitoring road section and the background (IEE of CPLA) is 6.4 × 1014 molecule/cm2 -1.96 × 1016 molecule/cm2. Due to the effects of vehicle type,traffic and other factors,the overall average concentration of northeast section is higher than southwest..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2645 (2009)
Diffraction and Gratings
Fabrication and Study of 2000 l/mm X-Ray Self-Standing Transmission Gratings
Li Hailiang, Wu Jian, Zhu Xiaoli, Xie Changqing, Liu Ming, and Cao Leifeng
Within the limit of fabricating techniques,2000 l /mm self-standing transmission gratings model was designed. And by combining the techniques of electronic-beam lithography and X-ray lithography,the 2000 l /mm X-ray self-standing transmission gratings was fabricated. Firstly,the electronic-beam lithography and micro-elWithin the limit of fabricating techniques,2000 l /mm self-standing transmission gratings model was designed. And by combining the techniques of electronic-beam lithography and X-ray lithography,the 2000 l /mm X-ray self-standing transmission gratings was fabricated. Firstly,the electronic-beam lithography and micro-electroplating technology was used to prepare a master mask of gratings on polyimide membrane substrate. Then by using X-ray lithography and micro-electroplating,child gratings was replicated on the master mask. And the self-standing graph was transferred to the daughter gratings via utraviolet (U-V) lithography and micro-electroplating. Finally,with the technology of etching and inductively coupled plasma (ICP),the fabrication of X-ray self-standing transmission gratings was fulfilled. From the fabrication results of the gratings,it shows that bars smoothness,the absent ratio and the profile of the gratings are all desired..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2650 (2009)
Characteristics of Long-Period Fiber Grating Coated with Double-Layer Films Including Metal Film
Deng Chuanlu, Gu Zhengtian, and Zhang Jiangtao
Based on the coupled-mode theory,the complex characteristic equation of long-period fiber gratings coated with metal film and sensing film is set up. By using the perturbation method,the complex roots are obtained. The results are coincident with the results of Reference[5]. The curves of intensity and the transmissionBased on the coupled-mode theory,the complex characteristic equation of long-period fiber gratings coated with metal film and sensing film is set up. By using the perturbation method,the complex roots are obtained. The results are coincident with the results of Reference[5]. The curves of intensity and the transmission spectrums are significantly influenced by the extinction coefficient. The proportion of the even mode′s intensity in core is much larger than that of the odd mode′s intensity. Also,the amplitude of the attenuation peak of the even mode is much larger than that of the odd mode. So the even mode is taken as the research object when the metal coated long-period fiber grating sensor is optimized. Furthermore,the influence of metal and sensitive film parameters on the resonant characteristics is analyzed in theory. The results show the metal film thickness,sensitive film thickness and refractive index influence the resonant wavelength,which shifts towards the short wavelength with the increase of the metal film thickness,sensitive film thickness and refractive index. And there is a jumping phenomenon for film parameters,so the film parameters corresponding to the jumping phenomena must be discarded in actual applications of long period fiber gratings (LPFG)..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2656 (2009)
Characteristics of Long-Period Optical Fiber Grating with High Refractive Index nm-Thick Film Overlay
Yu Xiujuan, Zhang Min, Wang Liwei, Lei Ming, and Liao Yanbiao
The sensing theoretical model of long-period gratings (LPGs) with high-refractive-index nanometer film coating is built. The influence of overlay thickness and external refractive index on the resonant wavelength of LPG is investigated theoretically. The phenomenon of reorganization of cladding modes at different coatiThe sensing theoretical model of long-period gratings (LPGs) with high-refractive-index nanometer film coating is built. The influence of overlay thickness and external refractive index on the resonant wavelength of LPG is investigated theoretically. The phenomenon of reorganization of cladding modes at different coating film thicknesses is shown and explained in detail. The theoretical analysis shows that a significant modification of the distribution of cladding modes is seen as an azimuthally symmetric nanoscale high-refractive-index coating deposited on the cladding of LPG. If the parameters of layers (the refractive index and thickness) and the external refractive index are chosen accurately,the lowest cladding mode HE1,2 will become the overlay mode and other cladding modes will experience mode transition. For the lower cladding modes (such as HE1,6),there is two-step modes transition. For higher cladding modes(such as HE1,14),there is only the one-step modes transition. The mode transition on the sensitivity of the external refractive index is also analyzed:Modes transition shifts to lower refractive index region with the increase of the overlay thickness..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2665 (2009)
Fiber Optics and Optical Communications
Guided Modes in a Four-layer Slab Waveguide with the LHM Core
Zhang Jing, He Ying, Li Chunfang, and Zhang Fanming
The guided modes are studied in a four-layer left-hand meterial (LHM) slab waveguide structure with a negative refractive material core and three traditional dielectric layer. The graphical method is applied to determine the TE guided modes. The LHM waveguide supports both oscillating guided modes and surface guided moThe guided modes are studied in a four-layer left-hand meterial (LHM) slab waveguide structure with a negative refractive material core and three traditional dielectric layer. The graphical method is applied to determine the TE guided modes. The LHM waveguide supports both oscillating guided modes and surface guided modes. The guided modes in the four layer LHM waveguide have some new properties compared to the three-layer waveguide. When the oscillating field exists both in the inner traditional dielectric layer and in the LHM layer,the fundamental mode appears and some high-order modes are absent. And when surface guided modes exist in the LHM layer with the oscillating field in the inner dielectric layer,mode double-degeneracy appears for the high-order modes. The four-layer LHM waveguide is equivalent to the asymmetric three-layer waveguide when the evanescent field exists in the inner dielectric layer. These novel properties are valuable for the fabrication of the optical waveguides in the future..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2673 (2009)
Characterization of Terahertz Hollow Fiber with an Absorptive Inner-Coating Dielectric Layer
Tang Xiaoli, and Shi Yiwei
Dielectric-coated metallic hollow fiber is one of the promising media for THz transmission. The dielectric layer enhances the reflection rate and hence lowers the transmission loss,whereas it brings additional loss due to its material absorption. The influence of dielectric absorption on the structure parameters of theDielectric-coated metallic hollow fiber is one of the promising media for THz transmission. The dielectric layer enhances the reflection rate and hence lowers the transmission loss,whereas it brings additional loss due to its material absorption. The influence of dielectric absorption on the structure parameters of the hollow fiber is theoretically discussed. Calculation results show that the optimum refractive index of an absorptive dielectric layer is greater than that of a perfect transparent dielectric layer. The optimum thickness of the dielectric layer to minimize the loss of HE11 mode becomes smaller due to the absorption. The absorption tolerance is also investigated when considering such factors as inner diameter,refractive index,and transmission wavelength. It is shown that absorption tolerance decreases when the inner diameter becomes smaller or when the transmission wavelength becomes larger. In extreme cases of small inner-diameter or large transmission wavelength,the absorption tolerance is not existent. The calculation results are useful to the structure design and material selection in the fabrication of terahertz hollow fibers..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2681 (2009)
Tapers in Electro-Optic Polymer Waveguides
Hong Jianxun, Xu Kai, Zhou Liming, Zhou Jianxin, Chen Shuiping, Li Chengjun, Wu Youyu, and Chen Wei
A tapered electro-optic polymer waveguide is proposed and designed for coupling light between single-mode optical fiber and polymer waveguide. The tapered waveguide performs mode transformation between optical fiber mode and polymer waveguide mode by using a refractive index taper and a width taper with wedge profile. A tapered electro-optic polymer waveguide is proposed and designed for coupling light between single-mode optical fiber and polymer waveguide. The tapered waveguide performs mode transformation between optical fiber mode and polymer waveguide mode by using a refractive index taper and a width taper with wedge profile. Wedge width taper possess smaller loss and is easy to make. The refractive index taper can be fabricated by utilizing a gray-scale mask lithography to control the UV light reaching each portion of the taper. The transmission loss of the tapers that depend on taper length,waveguide width and height,material loss are analyzed. The optimization of the design is discussed. The total power,mode distribution and its transformation through the taper are presented. The transmission loss of the taper is less than 0.37 dB,which results in an 8.78 dB insertion loss improvement and a low fiber-to-fiber component loss of 1.62 dB. The mode transformation efficiency is 83.7%..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2686 (2009)
Improved Fiber Design and Fabrication of Non-Zero Dispersion-Shifted Fibers
Wu Jindong, Wu Xingkun, Lu Weimin, Wu Haigang, Zhang Liyong, and Huang Xiaopeng
A novel design of non-zero dispersion-shifted fiber and its fabrication by MCVD+OVD process are presented. An effective-area of greater than 71 μm2 is obtained for the designed fiber. Dispersion characteristics is improved by reducing 1550 nm dispersion slope from 0.0715 ps/(nm2·km) to 0.0605 ps/(nm2·km)or 0.A novel design of non-zero dispersion-shifted fiber and its fabrication by MCVD+OVD process are presented. An effective-area of greater than 71 μm2 is obtained for the designed fiber. Dispersion characteristics is improved by reducing 1550 nm dispersion slope from 0.0715 ps/(nm2·km) to 0.0605 ps/(nm2·km)or 0.0466 ps/(nm2·km),while zero dispersion wavelength was shifted from 1500 nm to 1450 nm. Experimental measurement indicates that the fabricated fiber has an excellent optical transmission property with a excellent macro-bending and splice performance,suitable for high-speed long haul dense wavelength division multiplexing systems in C+L or S+C+L bands. This innovative design procedure utilizes accurate perturbation algorithm for fine adjustment of key-part of fiber configuration,the method is not limited to MCVD process and non-zero dispersion-shifted fibers,but also can be applied for the development of specialty fibers..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2692 (2009)
Photoluminescence Spectra of CdSe/ZnS-Quantum Dot Doped Fiber with High Doping Concentrations
Cheng Cheng, Zeng Feng, and Cheng Xiaoyu
Optical fibers doped with highly concentrated CdSe/ZnS quantum dot (QD) are prepared,and their photoluminescence (PL) spectra are measured. The doping concentration and the fiber length,corresponding to the maximum PL peak,are determined by analyzing the respective PL spectrum. Compared with low doping concentrations,tOptical fibers doped with highly concentrated CdSe/ZnS quantum dot (QD) are prepared,and their photoluminescence (PL) spectra are measured. The doping concentration and the fiber length,corresponding to the maximum PL peak,are determined by analyzing the respective PL spectrum. Compared with low doping concentrations,the observed peak intensities enhance greatly within 1 cm fiber length,and decrease gradually as the fiber length increases. The exciting intensity at 473 nm shows an exponential attenuation with an extinction coefficient of 0.26-1.02 cm-1. Given the exciting intensity and the exciting wavelength,the total amount of QD that can be added to obtain the maximum PL emission is a constant. A red shift of the PL-peak wavelength reaches to 8-15 nm,depending on the doping concentration and the fiber length. These results provide a reference in the development of possible quantum dot-doped fiber amplifiers in the future..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2698 (2009)
Fourier Optics and Signal Processing
Research on the Phase Retrieval Algorithm Used for Multiple-Image Encryption with Region Multiplexing
Shi Yishi, and Zhang Jingjuan
The effect of diffractive shadow evidently degrades the performance of the multiple-image encryption system based on double phase encoding. The region multiplexing is proposed to solve this problem. Since multiple images to be encrypted are located in different regions of each output plane,the noise arising from the efThe effect of diffractive shadow evidently degrades the performance of the multiple-image encryption system based on double phase encoding. The region multiplexing is proposed to solve this problem. Since multiple images to be encrypted are located in different regions of each output plane,the noise arising from the effect of diffractive shadow can be suppressed. The corresponding phase retrieval algorithm is studied through theoretical analysis and computer simulations. After the whole iterations with the normal sequence,the image with the worst decrypted quality is compensated one by one. In this way,we can obtain the sequence of sub-iteration which is objectively suitable for the characters of multiple images to be encrypted. Based on this sequence,either an adjusting iteration after the whole iterations with the original sequence or completely changing the sequence of the whole iterations can be adopted. As a result,maintaining the advantage of the phase retrieval algorithm converging fast,both the quality of all decrypted multiple images and the multiplexing capacity of the system can be improved..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2705 (2009)
Digital Watermarking Technique Based on Cascaded Fractional Fourier Transform System
He Mingzhao, Cao Liangcai, Tan Qiaofeng, He qingsheng, and Jin Guofan
A novel digital watermarking method by optical cascaded fractional Fourier transform and random phase encoding is proposed. This method can be served as an effective way of information hiding and protection. Experimental results show that this watermarking method has strong robustness against noise,shearing,rotation,reA novel digital watermarking method by optical cascaded fractional Fourier transform and random phase encoding is proposed. This method can be served as an effective way of information hiding and protection. Experimental results show that this watermarking method has strong robustness against noise,shearing,rotation,resizing,and medium filtering. This watermarking method is based on optical cascaded fractional Fourier transform system. The watermark information is iterative fractional Fourier transformed and embedded into host image. And two phase distributions can be obtained as keys to protect the watermark information. With the introduction of double phase encoding,the key space of this watermark system is greatly enlarged. As a result the security of this watermark system is enhanced. This watermark technique can be implemented both optically and digitally..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2709 (2009)
Image Processing
An Image Fusion Algorithm Using Pseudo Wigner Ville Distribution
Liu Cong, Li Yanjun, and Zhang Ke
An image fusion algorithm using pseudo-Wigner Ville distribution (PWVD) is proposed.Firstly,a 1-D pseudo Wigner Ville distribution fuction is applied to nonoverlapping N-pixel window slices of the original image in different orientations,the resultant data is arranged as N energy maps according to the orientation whereAn image fusion algorithm using pseudo-Wigner Ville distribution (PWVD) is proposed.Firstly,a 1-D pseudo Wigner Ville distribution fuction is applied to nonoverlapping N-pixel window slices of the original image in different orientations,the resultant data is arranged as N energy maps according to the orientation where the mean square root is max. Then,the fusion principle of multiscale decomposition of the source images is the max partial energy of energy map in high frequency and the max variance of energy maps in low frequency. So,the resultant data can be arranged as N energy maps in different frequencies. Finally,the fused image is formed through contrary PWVD to the fused energy maps. The fusion experiment for infrared and visible images,multifocus images,computer X-ray tomography and magnetic resonance images,infrared and synthetic aperture radar images are taken,and the entropy comparison between fused image and source images is given. The results show that the fused image obtained by the presented algorithm preserves the abundant information of the source image..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2716 (2009)
Image Retrieval Based on Text-Retrieval Technology
Zhao Shan, and Tang Yongli
In order to introduce effectively text-retrieval technologies into content-based image retrieval,a novel method is presented. Firstly,according to the human visual feature and principle of the block truncation code (BTC),the image is divided into non-overlapped and equally-sized sub-blocks which can embody the texture In order to introduce effectively text-retrieval technologies into content-based image retrieval,a novel method is presented. Firstly,according to the human visual feature and principle of the block truncation code (BTC),the image is divided into non-overlapped and equally-sized sub-blocks which can embody the texture and edge information of the original image. These blocks are defined and the sub-features are extracted,based on which the image is mapped into the text. Then,the text is chosen as key words and the technology of text-based retrieval is adopted for image retrieval. The content of the image and the text-based retrieval technology are considered,and experimental results have shown that the proposed method has sound and robust retrieval performance..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2721 (2009)
The Coherent Speckle Suppression Method in SAR image Based on Contourlet Domain Adaptive BivaShrink Model
Wang Wenbo, Zhang Xiaodong, Fei Pusheng, and Yi Xuming
In order to preserve the textural feature affected by multiplicative speckle in high resolution synthetic aperture radar (SAR) images,a despeckling metod,based on contourlet domain adaptive BivaShrink denoising model,is proposed to suppress the speckle in SAR images. By calculating the variance homogeneous measurement In order to preserve the textural feature affected by multiplicative speckle in high resolution synthetic aperture radar (SAR) images,a despeckling metod,based on contourlet domain adaptive BivaShrink denoising model,is proposed to suppress the speckle in SAR images. By calculating the variance homogeneous measurement and local energy ratio,the shape and size of variance estimating windows are determined adaptively,and then the variance of original images can be estimated optimally. Expriments show that the proposed algorithm performs better on not only speckle reduction but also preservation of structural detail information than wavelet BivaShrink algorithm and contourlet threshold algorithm. Visual effect and experimental numerical index both are improved apparently..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2726 (2009)
Multiscale Image Fusion Algorithm Based on Subpixel Weighted Region Energy
Chai Yong, He You, and Qu Changwen
Dividing pixels in rectangular and circular regions into subpixels and determining weight of each subpixel the composite weighted region energy of each pixel is obtained in the region. The source images are decomposed into multiresolution representation firstly. Then we select average of the coarse parts and maximal paDividing pixels in rectangular and circular regions into subpixels and determining weight of each subpixel the composite weighted region energy of each pixel is obtained in the region. The source images are decomposed into multiresolution representation firstly. Then we select average of the coarse parts and maximal parts of the detail components based on the new weighted region energy as the fusion coefficients. Experimental results show that the proposed method has better fusion effects than traditional image fusion schemes based on the traditional region energy. From the evaluation of image definition and entropy,this method improves the quality of the fusion image..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2732 (2009)
Iteration Algorithm for Color Image Restoration of Wavefront Coding System with Cubic Phase Mask
Liu Qinxiao, Zhao Tingyu, Zhang Wenzi, and Yu Feihong
The cubic phase mask is used to extend the depth of field in a wavefront coding system,the point spread function is asymmetric. We research a new iteration algorithm to get the final sharp color image,which based on the GMRES (generalized minimal residual methods) combined with the regularization method and multichanneThe cubic phase mask is used to extend the depth of field in a wavefront coding system,the point spread function is asymmetric. We research a new iteration algorithm to get the final sharp color image,which based on the GMRES (generalized minimal residual methods) combined with the regularization method and multichannel processing procedure. In order to eliminate the ringing effect,Antireflective boundary conditions and Kronecker product approximation is used for the new image formation. Analysis and the simulation show that the new algorithm can give excellent deconvolution results and suppress the noise magnification effectively. From the experimental result,this new algorithm can give better results than classic Wiener filtering with little ringing effect on the image border and little vibration on the edge..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2738 (2009)
Registration Technique for High-Resolution Remote Sensing Images Based on Nonsubsampled Contourlet Transform
Chen Zhigang, Yin Fuchang, and Sun Fu
For the purpose of improving high-resolution remote sensing images registration precision,nonsubsampled contourlet transform is applied to high-resolution remote sensing images registration. Firstly,for nonsubsampled contourlet transform shift invariance,nonsubsampled contourlet transform is used to extract the images For the purpose of improving high-resolution remote sensing images registration precision,nonsubsampled contourlet transform is applied to high-resolution remote sensing images registration. Firstly,for nonsubsampled contourlet transform shift invariance,nonsubsampled contourlet transform is used to extract the images edge in contourlet transform domain and the feature points are extracted from images edge by selecting an appropriate threshold. Then,normalized cross-correlation matching and probability support matching method are used to match the images feature points. Finally,triangle-based local transformation function is employed to register the images. The experimental results show that this method can more accurately extract the corresponding feature points of high-resolution remote sensing images and increase correct matching probability and have more precise and more robust registration effect than the method based on wavelet..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2744 (2009)
Speckle Fringe Pattern Smoothing Method Based on Gabor Filtering
Li Kai, and Zhang Qingchuan
A method based on Gabor filtering for speckle fringe pattern smoothing is presented. The fringe frequencies and fringe gradient orientation of the speckle fringe pattern are obtained by windowed Fourier operation. The Gabor filters with the particular frequencies and orientation are then determined and applied to smootA method based on Gabor filtering for speckle fringe pattern smoothing is presented. The fringe frequencies and fringe gradient orientation of the speckle fringe pattern are obtained by windowed Fourier operation. The Gabor filters with the particular frequencies and orientation are then determined and applied to smooth the speckle fringe pattern. Simulation and experimental results show that the speckle noise in the speckle fringe patterns is removed efficiently as well as the fringe structure is well-preserved. This method provides a good basis for further extracting fringe phase field from one speckle fringe pattern..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2751 (2009)
Composite Image Contrast Enhancement Algorithm Based on Local Adaptive Stretching Window
Li Cheng, Ju Ming, Bi Duyan, and Liu Bo
Images suffering from poor luminance and contrast need enhancement before further processing or analysis. An algorithm based on local adaptive stretching window (LASW) technique is proposed. Since spatial contrast enhancement techniques by local manipulations show the pros and cons,the method combined with local and glImages suffering from poor luminance and contrast need enhancement before further processing or analysis. An algorithm based on local adaptive stretching window (LASW) technique is proposed. Since spatial contrast enhancement techniques by local manipulations show the pros and cons,the method combined with local and global manipulations is much more reasonable. Firstly,the high boost Laplacian unsharp mask (UM) operator is conducted for more hiding and edged information,then the LASW is operated on low contrast regions to develop details,and a locally adaptive filter is used to smooth the image further. At last,the global contrast adjustment is made after local manipulations. Experimental results show the good performance of the proposed algorithm with measure rules of enhancement by absolute mean brightness error and entropy,especially in the case of weak and low-contrast information in the image..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2756 (2009)
Multiscale Image Segmentation Based on Graph Weighted Kernel K-means
Li Yuchuan, and Tian Zheng
An improved minimum cut model is presented considering that the minimum cut criteria favors cutting small sets of isolated nodes,then equivalence relation between the improved minimum cut model and weighted kernel k-means is researched,and the influence of different similarity functions on the results of segmentation aAn improved minimum cut model is presented considering that the minimum cut criteria favors cutting small sets of isolated nodes,then equivalence relation between the improved minimum cut model and weighted kernel k-means is researched,and the influence of different similarity functions on the results of segmentation are also analysed. And based on these,a multiscale image segmentation method based on graph weighted kernel k-means is proposed,this method avoids calculating graph spectral,which is a key step when using graph cut model to segment images,also,it avoids selecting kernel matrix,which is important to the weighted kernel k-means,finally it realizes multiscale image segmentation. The analysis of anti-noise and experimental results on a number of optical images show the effectiveness of this method..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2762 (2009)
Iterative Image Restoration Algorithm Based on Contourlet Transform
Lou Shuai, Ding Zhenliang, and Yuan Feng
In consideration of the multi-scaled and multi-directional properties of contourlet transform and its better “sparse” representation of 2-D images,an image restoration algorithm based on contourlet transform is proposed. The algorithm adopts a bound optimization approach and is computed in the contourlet domain iteratiIn consideration of the multi-scaled and multi-directional properties of contourlet transform and its better “sparse” representation of 2-D images,an image restoration algorithm based on contourlet transform is proposed. The algorithm adopts a bound optimization approach and is computed in the contourlet domain iteratively by an expectation-maximization-type (EM-type) method,and then reaches to the optimal result of the penalized likelihood function finally. The experimental results show that,compared with the traditional algorithms based on the wavelet transform,the proposed algorithm based on contourlet transform can protect the detail and edge information of the restored image much better,with the peak singnal-to-noise ratio (PSNR) improvement about 0.6 dB-0.8 dB,and at the same time,the computational efficiency is also retained..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2768 (2009)
Imaging Systems
Imaging Quality of Double-Circle Sparse Aperture Array Configuration
Liu Li, Jiang Yuesong, and Wang Changwei
A new non-redundant double-circle sparse aperture array configuration,which is composed of two uniform circle arrays,is proposed,since the modulation transfer function (MTF) of the common uniform circle array usually has zero-value regions within the cut-off spatial frequency,which prejudice the image quality. The pupiA new non-redundant double-circle sparse aperture array configuration,which is composed of two uniform circle arrays,is proposed,since the modulation transfer function (MTF) of the common uniform circle array usually has zero-value regions within the cut-off spatial frequency,which prejudice the image quality. The pupil function and MTF have been given. Taking the five-three double circles array as an example,image performance is discussed in terms of the sub-aperture diameter,inner circle radius and inner circle rotation,based on the practical cut-off frequency. Imaging simulation and image restoration are given. The results show that,compared with the uniform circle array and Cornwell′s optimized circle array,the double circle array has higher practical cut-off frequency,and the image quality degrades with the decrease of filling factor..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2774 (2009)
Analysis of Three-Dimensional Measurement System and the Coordinates Calibration in Fourier Transform Profilometry
Wu Shuangqing, Zhang Yin, Zhang Sanyuan, and Ye Xiuzi
The optical geometry of the Fourier transform profilometry (FTP) which do not have coplanar and parallel limitations is analyzed through two different reference planes,and a fictitious exit pupil of the projector is introduced. The corresponding phase-height mapping is given based on ray tracing,a method to estimate thThe optical geometry of the Fourier transform profilometry (FTP) which do not have coplanar and parallel limitations is analyzed through two different reference planes,and a fictitious exit pupil of the projector is introduced. The corresponding phase-height mapping is given based on ray tracing,a method to estimate the parallelism is proposed. The camera coordinate system is applied to fulfill the calibration of the height and the lateral coordinates. Experiment results show the effectiveness and feasiblity of the proposed method..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2780 (2009)
Experimental Investigation of Intensity Correlated Three Dimensional Diffraction Tomography
Ying Guanrong, Liu Honglin, Wei Qing, and Han Shensheng
A new three-dimensional diffraction tomography,based on intensity correlation imaging,is demonstrated. Intensity correlated imaging (ghost imaging),which can realize the lensless Fourier-transform,the diffraction tomography and the two-step phase-retrieval algorithm are combined together to realize intensity correlatedA new three-dimensional diffraction tomography,based on intensity correlation imaging,is demonstrated. Intensity correlated imaging (ghost imaging),which can realize the lensless Fourier-transform,the diffraction tomography and the two-step phase-retrieval algorithm are combined together to realize intensity correlated three dimensional diffraction tomography by using 650 nm pseudo-thermal light. The theoretical basis of this technique is outlined,and the experimental results are presented. This paper is a preparation for the applications of incoherent X-ray intensity correlated three-dimensional diffraction tomography in the third generation X-ray synchrotron radiation source..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2786 (2009)
Instrumentation, Measurement and Metrology
Optimization Algorithm of Correlated Color Temperature for LED Light Sources by Dichotomy
Lin Yue, Ye Liewu, Liu Wenjie, and Lü Yijun
Color temperature and correlated color temperature (CCT) are important parameters of the LED light sources. The procedure for calculating colorimetric parameters,such as color coordinates (u,v) and CCT from spectra data,is rather complicated. An advanced algorithm is necessary to simplify the computation. Based on the Color temperature and correlated color temperature (CCT) are important parameters of the LED light sources. The procedure for calculating colorimetric parameters,such as color coordinates (u,v) and CCT from spectra data,is rather complicated. An advanced algorithm is necessary to simplify the computation. Based on the definition of chromaticity,the advantages and disadvantages of three classical CCT algorithms are analyzed,respectively,and a new dichotomy optimization algorithm is proposed,whose principle and procedure are illustrated in detail. By comparing the results of dichotomy with the other classical algorithms by Planck formula and actual white LEDs spectra,it is proved that the dichotomy is a CCT algorithm with higher accuracy and faster speed..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2791 (2009)
Application of Near Infrared Spectroscopy on Rapid Determination of Essential Components for Cordyceps Militaris
Wang Di, Zhang Aili, Meng Qingfan, Lu Jiahui, Jin Lu, and Teng Lirong
Partial least squares (PLS) method was applied to establish models with near infrared spectroscopy (NIRS) for quantitative analysis of polysaccharides,protein,cordycepic acid,adenosine content in cordyceps militaris mycelium. The origin spectra were used to establish the PLS models for quantitative analysis of adenosinPartial least squares (PLS) method was applied to establish models with near infrared spectroscopy (NIRS) for quantitative analysis of polysaccharides,protein,cordycepic acid,adenosine content in cordyceps militaris mycelium. The origin spectra were used to establish the PLS models for quantitative analysis of adenosine and polysaccharides content in cordyceps militaris mycelium. The Savitzky-Golay smoothing spectra were applied to establish the PLS models for quantitative analysis of protein and cordycepic acid content. The values of root mean square error of cross-validation(RMSECV) of the most optimum PLS quantitative analysis models of polysaccharides,protein,cordycepic acid and adenosine were 0.0091,0.0222,0.0088 and 0.6520,the values of root mean square error of prediction(RMSEP) were 0.0079,0.0196,0.0087 and 0.5780. The results demonstrated that the quantitative analysis model for determining the four contents of cordyceps militaris mycelium possessed good stability and high precision. This method has great foreground in quantitative analysis of Chinese traditional medicine..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2795 (2009)
Genetic Algorithm Used for Predicting Meat and Bone Meal Content in Fishmeal by Near Infrared Spectroscopy
Zhan Xiaomei, Han Lujia, Liu Xian, and Yang Zengling
For the purpose of optimizing near infrared spectroscopy model,and improving the prediction result,Genetic Algorithm (GA) was used to select wavelength variables of near infrared spectroscopy for fishmeal adulterated with meat and bone meal. 310 wavelengths are selted in genetic algorithm. By contrast with all wavelengFor the purpose of optimizing near infrared spectroscopy model,and improving the prediction result,Genetic Algorithm (GA) was used to select wavelength variables of near infrared spectroscopy for fishmeal adulterated with meat and bone meal. 310 wavelengths are selted in genetic algorithm. By contrast with all wavelengths based partial least squares(PLS),GA based PLS reduced 80% of the wavelengths,and gained much better cross validation and prediction results. Related coefficient of cross-validation RCV was improved from 0.80 to 0.90,while the value of root mean square error of cross- validation (RMSECV) was reduced from 5.22% to 3.62%. The related coefficient of prediction RV was improved from 0.91 to 0.96,while the value of root mean square error of prediction (RMSEP) was reduced from 3.85% to 2.95%. GA improved the robustness and predictability of the model. It’s indicated that GA was an effective method for variable selection and could improve the prediction result of the meat and bone meal content in fishmeal by near infrared spectroscopy..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2800 (2009)
Interferometric Testing the Vertex Radius and Conic Constant of a Conic Surface
Wu Gaofeng, Chen Qiang, Hou Xi, and Fan Bin
Interferometric testing the vertex radius of curvature (ROC) and conic constant (CC) of a conic surface is calculating the radius and CC with radii difference and Seidel coefficients obtained by comparing the test surface with a spherical reference wavefront having a ROC equal to the local sagittal,medial,or tangentialInterferometric testing the vertex radius of curvature (ROC) and conic constant (CC) of a conic surface is calculating the radius and CC with radii difference and Seidel coefficients obtained by comparing the test surface with a spherical reference wavefront having a ROC equal to the local sagittal,medial,or tangential ROC. The method is explained in detail and the angle of the optical axis and normal of the conic segment is introduced and divided into two angles α and β to improve the mathematical model. Angle β can be removed because of the symmetry of the segment according to the specific Zernike coefficients to simplify the new model. Equations about the vertex ROC and CC are derived with α and the simulation program is compiled. The maximum Seidel coefficients diffidence between theoretical calculation and simulations of a paraboloidal (=100 mm,F=3) is 0.0002 λ when α is 0.03° and β is 0. The research indicates that there are the same characteristic relations of the Seidel coefficients at the three positions even with the angle α..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2804 (2009)
Feasibility Study for the Use of Near-Infrared Spectroscopy in the Quantitative Analysis of TVB-N Content in Pork
Cai Jianrong, Wan Xinmin, and Chen Quansheng
To non-destructively determine the freshness of pork rapidly,near-infrared (NIR) spectroscopy was applied to quantitative the content of total volatile basic nitrogen (TVB-N) in pork which was an important index of pork freshness. The raw spectra of pork was preprocessed by the normaliyation method of standard deviatioTo non-destructively determine the freshness of pork rapidly,near-infrared (NIR) spectroscopy was applied to quantitative the content of total volatile basic nitrogen (TVB-N) in pork which was an important index of pork freshness. The raw spectra of pork was preprocessed by the normaliyation method of standard deviation (SNV). Synergy interval partial least squares (siPLS) algorithm was used to build the precessed spectra of pork and calibration model of TVB-N content and that model was compared with the models respectively built by classical partial least squares (PLS) and interval PLS (iPLS) algorithms. Experimental results showed that the performance of siPLS model was the best in contrast to PLS and iPLS. The optimal calibration model was achieved with correlation coefficient (Rc=0.8332),root mean square error of cross-validation (fRV=3.75) in calibration set and correlation coefficient (Rp=0.8238),root mean squared error of prediction (fRP=4.17) in prediction set. This study demonstrated that NIR spectroscopy with siPLS can be successfully applied as a rapid method to determine the TVB-N of pork rapidly..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2808 (2009)
Measurement of Monochromator′s Angle Repeatability by Phase Plate Diffraction Collimation Method
Gong Zhihua, Chen Min, Wang Yong, Yan Rui, and Tai Renzhong
In order to measure the mechanical angle repeatability of the variable-included-angle plane-grating-monochromator used in soft X-ray spectro-microscopy beamline at Shanghai Synchrotron Radiation Facility,a new method was proposed based on the phase plate diffraction collimation. This system was designed combining laserIn order to measure the mechanical angle repeatability of the variable-included-angle plane-grating-monochromator used in soft X-ray spectro-microscopy beamline at Shanghai Synchrotron Radiation Facility,a new method was proposed based on the phase plate diffraction collimation. This system was designed combining laser diode fiber with phase plate diffraction collimation technique. A 2-dimension CCD was adopted to collect the images,which was used to measure the displacement of the light spot,thus the angle repeatability of the plane mirror and the grating could be determined. The results show that this method could be used to measure the monochromator′s angle repeatability in a higher precision estimated to be ±0.1″,which is better than that measured by the commercial ELCOMAT 3000 auto collimator used in the same condition..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2813 (2009)
Real-time Wavelet Transform Based Coherent detecting Brillouin Optical Time Domain Reflectometer
Song Muping, and Chen Xiang
In Brillouin optical time domain reflectometer,the detected spontaneous Brillouin scattering light is very weak,and the Brillouin frequency shift is only about 11 GHz. The coherent detect is a good method,but the detected signal is a wideband amplitude-modulated signal,which is hard to demodulate. The real-time Morlet In Brillouin optical time domain reflectometer,the detected spontaneous Brillouin scattering light is very weak,and the Brillouin frequency shift is only about 11 GHz. The coherent detect is a good method,but the detected signal is a wideband amplitude-modulated signal,which is hard to demodulate. The real-time Morlet wavelet transform is adopted to overcome this problem. The experimental procedures and results are presented in the text. A laboratorial system of 25 km distributed Brillouin optical time domain refractor is achieved,with the stress resolution of 40 με,the spatial resolution of 5m and the system response time of 1 minute..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2818 (2009)
Lasers and Laser Optics
External Optical Cavity Locked by Laser Frequency
Li Chuanliang, Deng Lunhua, Yang Xiaohua, and Chen Yangqin
With the peak-seeking servo-controlled technology based on a residual error,an external optical cavity can keep in resonance with the frequency of Ti-sapphire laser in the experiment. The servo loop uses a piezoelectric transducer (PZT) as a modulator,which modulates the intensity of the transmitted light passing throuWith the peak-seeking servo-controlled technology based on a residual error,an external optical cavity can keep in resonance with the frequency of Ti-sapphire laser in the experiment. The servo loop uses a piezoelectric transducer (PZT) as a modulator,which modulates the intensity of the transmitted light passing through the cavity. The servo signal is obtained from the lock-in amplifier,then it is amplified by a high voltage amplifier,which adjusts the length of the cavity according to the laser frequency. In this approach,the resonant frequency of the cavity can be locked to the laser frequency for a long time as the laser operates in a fixed frequency and the relative fluctuation of output power from the cavity is lower than 2%. When the frequency of the laser scans,the cavity is also capable to follow the variation of laser frequency automatically in an uninterrupted range of 2 GHz..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2822 (2009)
Machine Vision
Extended Object Tracking Method Based on Straight-Line Edge Feature Matching
Zhang Jianwei, and Zhang Qiheng
In order to track the extened object stably and precisely,firstly,all straight-line edge features in extended object between neighboring frames are extracted and every intersection of straight-line feature edge can be described by slopes,obliquities and intercepts of two straight lines,then the intersections are matcheIn order to track the extened object stably and precisely,firstly,all straight-line edge features in extended object between neighboring frames are extracted and every intersection of straight-line feature edge can be described by slopes,obliquities and intercepts of two straight lines,then the intersections are matched between neighboring frames by computing the Euclidean distance minimum of descriptors,finally the centroid of intersections is considered as the tracking position. Experimental results show that the method has an excellent performance in the object tracking. If the object does not transform greatly,the tracking method is more stable and more precise than ordinary template matching method..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2826 (2009)
Calibration Approach to Single-Camera Virtual Computer Mouse
Li Weixian, Zhou Fuqiang, Zhang Luming, and Yang Xiaoke
The mathematical model of a single-camera virtual computer mouse sensor is established and a field calibration approach to the single-camera virtual mouse is proposed. The mapping from the camera coordinates in working status to the screen coordinates can be calibrated through one media planar target in the camera′s fiThe mathematical model of a single-camera virtual computer mouse sensor is established and a field calibration approach to the single-camera virtual mouse is proposed. The mapping from the camera coordinates in working status to the screen coordinates can be calibrated through one media planar target in the camera′s field of view and one virtual target on the screen. Calibrating the single-camera virtual mouse is completed by efficiently establishing an available correspondence between the three-dimensional control point in space and the point of the mouse in the operating system. The proposed approach has an easy operation,and demands no extra costly tools. In the work range of 30 cm and with 50 features from image in 640 pixel×480 pixel,the RMS errors of the control point coordinates in the screen under test are within 3 pixels when the image noise variance reaches 1 pixel. The demo program shows the proposed approach is practicable and is applicable to field calibration for virtual mouse based on the tip of the user′s nose..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2832 (2009)
Estimation of Color Optical Flow Based on Geometric Algebra
Li Maokuan, and Guan Jian
A new optical flow estimation method for color image sequence is proposed,from a new point of view,the probability and simplicity of using the concept of geometric algebra to analyse color optical flow is discussed in detail. Color image sequence is presented by multivectors in geometric algebra,it is proved that if meA new optical flow estimation method for color image sequence is proposed,from a new point of view,the probability and simplicity of using the concept of geometric algebra to analyse color optical flow is discussed in detail. Color image sequence is presented by multivectors in geometric algebra,it is proved that if meet the constrained conditions for color optical flow analysis,a multivector instead of multichannel image processing method can be used to represent the continued distribution of images to expand the measurement range. then a new optical flow constraint equation and its solution in geometric algebra domain was deduced based on color invariance under motion,The experimental results of several synthesized and natural image sequences show that this algorithm can improve the ability of color optical flow estimation in different conditions greatly..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2837 (2009)
Measurement and Analysis of Water Mist Droplet Size Based on Machine Vision
Yuan Jiangtao, Yang Li, Wang Xiaochuan, Zhang Jian, and Jin Renxi
In order to meeting the demand of measuring the water mist droplet size with high accuracy and low cost,the machine vision measuring technique for the droplet size was studied in depth. The water mist droplets were sampled in self-building high pressure spraying system and droplets collecting device,the photos of the dIn order to meeting the demand of measuring the water mist droplet size with high accuracy and low cost,the machine vision measuring technique for the droplet size was studied in depth. The water mist droplets were sampled in self-building high pressure spraying system and droplets collecting device,the photos of the droplets sample were taken by the microscope and its CCD camera,the droplets sample photos were processed and analysed using the image processing software. The total number of the measured and counted droplets was 5966. The droplet size spectral,cumulative distribution and the droplet mean and indicated diameter were obtained. The machine vision measuring results were compared with the PDPA measuring results. Results indicate that the minimum droplet which the machine vision technique can be used to measure is 4.39 μm,and the machine vision results are close to the PDPA measuring results.The relative errors of the water mist droplet mean and indicated diameter are less than 5%,and that of the droplet size dispersion coefficient is 0.27%..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2842 (2009)
Materials
First-Principles Calculation of Electronic Structure and Optical Properties of CrSi2 with Doping Mn
Zhou Shiyun, Xie Quan, Yan Wanjun, and Chen Qian
The electronic structure and optical properties of Mn-doped CrSi2 have been calculated using the first-principles pseudo-potential method based on density functional theory. The calculated results show that CrSi2 is an indirect semiconductor and the indirect band gap is 0.35 eV,the Fermi level enters conduction band anThe electronic structure and optical properties of Mn-doped CrSi2 have been calculated using the first-principles pseudo-potential method based on density functional theory. The calculated results show that CrSi2 is an indirect semiconductor and the indirect band gap is 0.35 eV,the Fermi level enters conduction band and the band gap narrows after it was doped with Mn,with the indirect band gap width ΔEg=0.24 eV and CrSi2 changes into n-type semiconductor thereafter. There are some changes of optical parameters after doping. The static dielectric constant before doping is ε1(0)=32,then it changes to ε1(0)=58 after doping. Moreover the influence on electronic structure,density of states and optical properties of CrSi2 after Mn doping is analyzed as well. The work could provide theoretical basis for doping of CrSi2 materials in future research..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2848 (2009)
1×3 Beam Splitter Based on Photonic Crystal Waveguides Directional Coupler
Chen Shuwen, Zhu Guixin, Yu Tianbao, Liao Qinghua, Liu Nianhua, and Huang Yongzhen
Directional coupler can be constructed by parallelly putting five photonic crystal waveguides together. The propagation of the optical field entering this system symmetrically is analyzed numerically on the basis of self-imaging principle. 1×3 beam splitter,whose length can be as short as 14.26 μm,is designed by uDirectional coupler can be constructed by parallelly putting five photonic crystal waveguides together. The propagation of the optical field entering this system symmetrically is analyzed numerically on the basis of self-imaging principle. 1×3 beam splitter,whose length can be as short as 14.26 μm,is designed by using this structure. By symmetrically tuning the effective refractive index of two dielectric rods in the coupler,and accordingly inducing the redistribution of the electric field,equipartition or free distribution of output energy can be achieved. By asymmetrically tuning the effective refractive index of one dielectric rod in the coupler,free distribution of output energy can also be achieved. Due to the ultracompact size and the free modulation of output energy,the device has extensive practical value in future photonic integrated circuits..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2898 (2009)
Fabrication of FCC Structure Colloidal Photonic Crystals and Characteration of Band-Gap Measured
Yan Haitao, Wang Ming, Ge Yixian, Yu Ping, and Liu Qing
Based on the transmission characteration of optical fiber and the methods of fabrication colloidal photonic crystals,electric field-controlled method is used to fabricate colloidal photonic crystals with the photonic band-gap(PBG) in communications wavelength. RSOFT is used to simulate PBG characteration of colloidal pBased on the transmission characteration of optical fiber and the methods of fabrication colloidal photonic crystals,electric field-controlled method is used to fabricate colloidal photonic crystals with the photonic band-gap(PBG) in communications wavelength. RSOFT is used to simulate PBG characteration of colloidal photonic crystals and the parameters of colloidal microsphere are obtained. By the self-assembled method,the stepping motor is used to control the glass substrate,with the rate of 5 μm/s. At the same time an electric field is applied in the process of the colloidal crystals growth. The scanning electron microscopy is used to observe the surface of colloidal photonic crystals. An optical fiber system is designed to test PBG center wavelength of colloidal photonic crystals. Transmission spectrum shows the PBG of this colloidal crystals at 1552 nm. The agreement is very good between the experimental results and the simulation results,with the error of only 2 nm..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2905 (2009)
Dual Resonance Interference of Cascaded LPG Inscribed in Photonic Crystal Fiber
Wang Zhi, Zhang Limei, Wang Jing, and Yu Kuanglu
The propagation properties of the long-period fiber grating (LPG) pair in standard single-mode fiber (SMF) are discussed including some factors affecting the interference transmission spectra,and the characteristics of the LPG pair in the photonic crystal fiber (PCF) at the U-band near 1665 nm are investigated in detaiThe propagation properties of the long-period fiber grating (LPG) pair in standard single-mode fiber (SMF) are discussed including some factors affecting the interference transmission spectra,and the characteristics of the LPG pair in the photonic crystal fiber (PCF) at the U-band near 1665 nm are investigated in detail. A dual resonance interference spectrum is obtained after the structural parameters of the LPG pair in PCF are designed based on the relation between coupling strength and the beat length as well as the relation between beat length and wavelength. The spectra at both resonance wavelength are different due to the different coupling strength..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2909 (2009)
Filtering Characteristics and Application of Defect Mode of One-Dimensional Photonic Crystal
Wang Jizhou, Xiong Yuqing, Wang Duoshu, Chen Tao, and Liu Hongkai
The filtering characteristics of one-dimensional photonic crystal with defect mode was studied in detail,and the relevant influencing factors and rules have been emphasized. At the same time the possibility of designing multi-channel narrow band-pass filters using photonic crystals was demonstrated,the results show thaThe filtering characteristics of one-dimensional photonic crystal with defect mode was studied in detail,and the relevant influencing factors and rules have been emphasized. At the same time the possibility of designing multi-channel narrow band-pass filters using photonic crystals was demonstrated,the results show that it is possible to design multi-channel narrow filters using one-dimension photonic crystals. Finally a dual-channel narrow band-pass filter satisfying actual demand is designed and prepared..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2914 (2009)
Medical Optics and Biotechnology
Single-Cell Raman Spectral Analysis of Oxygenated and Deoxygenated Thalassemia Erythrocytes
Chen Xiuli, Wang Guiwen, Yin Xiaolin, Liu Junxian, Yao Huilu, Huang Shushi, and Li Yongqing
A laser tweezers Raman spectroscopy (LTRS) system was used to investigate the capacity of carrying oxygen in thalassemia erythrocytes. Single erythrocyte from patients with thalassemia HbH-CS and normal donors were trapped,and the Raman scattering signal of trapped cell was collected. The intensity ratio of band 1638 cA laser tweezers Raman spectroscopy (LTRS) system was used to investigate the capacity of carrying oxygen in thalassemia erythrocytes. Single erythrocyte from patients with thalassemia HbH-CS and normal donors were trapped,and the Raman scattering signal of trapped cell was collected. The intensity ratio of band 1638 cm-1 to band 1547 cm-1 (I1638/I1547) was selected to distinguish oxygenated erythrocytes from deoxygenated ones. By comparing the oxygenation cycle of optically trapped single red blood cells and the deoxygenated cells population from the two kinds of specimen,and analyzing the oxygenated and deoxygenated states,it is found that,in the oxygenation cycle,the ratio I1638/I1547 of thalassemia HbH-CS was much higher than that of normal control in deoxygenated state and slightly higher than the normal control in oxygenated state. In the population statistic,46% of the red blood cells from the normal control reach oxygenated state,but thalassemia HbH-CS only 15%,if the base is set by less than the average of I1638/I1547 from normal control cells. The result shows that the red blood cells of thalassemia HbH-CS are easy to oxygenate,but difficult to deoxygenate. The individual difference between thalassemia HbH-CS erythrocytes is obvious. This study provides the spectral vision on the oxygenation of thalassemia HbH-CS erythrocytes and the laboratorial referrences for the diagnosis and treatment..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2854 (2009)
Gastric Cancer Detection Using Diffuse Reflectance Spectral Ratio R540/R575 of Oxygenated Hemoglobin Bands
Li Lanquan, Wei Huajiang, He Bohua, Guo Zhouyi, Yang Hongqin, Xie Shusen, Chen Xuemei, Li Libo, Wu Guoyong, and Lu Jianjun
Differential diagnosis of epithelial tissues of normal human gastric,undifferentiated gastric adenocarcinoma,gastric squamous cell carcinomas,and poorly differentiated gastric adenocarcinoma were studied using the mean diffuse reflectance spectral ratio (R540/R575) of the oxygenated hemoglobin absorption bands. Exvivo Differential diagnosis of epithelial tissues of normal human gastric,undifferentiated gastric adenocarcinoma,gastric squamous cell carcinomas,and poorly differentiated gastric adenocarcinoma were studied using the mean diffuse reflectance spectral ratio (R540/R575) of the oxygenated hemoglobin absorption bands. Exvivo diffuse reflectance spectra in the 400 nm to 600nm region was measured from surgically removed gastric lesions using a spectrophotometer with an integrating sphere attachment. The results showed that the reflectance spectral intensity of the malignant tissues was lower than that of human normal gastric tissues and showed dips at 540 nm and 575 nm owing to absorption from oxygenated hemoglobin. Measurements carried out,the diffuse reflectance spectral ratio for epithelial tissues of normal human gastric,undifferentiated gastric adenocarcinoma,gastric squamous cell carcinomas,and poorly differentiated gastric adenocarcinoma were (94.2±2.4)%,(109±3.0)%,(103±2.8)% and (98.6±2.6)% respectively..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2860 (2009)
Optical Design and Fabrication
Integrated Analysis and Simulation of Opto-Mechanical System
Shi Jianliang, and Ren Ge
With the comparison to traditional design method in opto-mechanical system,the basic frame of integrated analysis and simulation was conceived. A mirror in telescope was taken as an example,and Patran,Matlab/Simulink and Zemax were selected as the software environment,the each independent model was set up respectively,With the comparison to traditional design method in opto-mechanical system,the basic frame of integrated analysis and simulation was conceived. A mirror in telescope was taken as an example,and Patran,Matlab/Simulink and Zemax were selected as the software environment,the each independent model was set up respectively,the realization methods for integrated analysis were discussed. On the basis of brief study on model generation and model reduction,the structural control interface tool was developed,and the structure control integrated analysis in mechanical/optical system was implemented. On the basis of study on dynamic data exchange (DDE),the method to the problem of a large number of ray tracing was discussed. The DDE of Matlab and Zemax and optical control integrated analysis in opto-mechanical system were implemented. The purpose of opto-mechanical control integrated analysis in opto-mechanical system was achieved..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2866 (2009)
Design of SG-III X-Ray Streak Camera
Hu Xin, Liu Shenye, Ding Yongkun, Yang Qinlao, Tian Jinshou, and He Xiao′an
According to its′ operation and target chamber′s structure,the X-ray streak camera built synchronously would make a great difference from the traditional one.It will be used not only to measure the time history of the physical process but also to monitor the synchronization among the 48 laser beams on SG-Ⅲ laser faciliAccording to its′ operation and target chamber′s structure,the X-ray streak camera built synchronously would make a great difference from the traditional one.It will be used not only to measure the time history of the physical process but also to monitor the synchronization among the 48 laser beams on SG-Ⅲ laser facility. The X-ray streak camera is composed of modules,which has a goal of temporal resolution of 10 ps and spatial resolution of 15 lp/mm . Its′ photocathode is sensitive to photon energy ranging from 100 eV to 10 keV. The camera system contains a hermetical air box,streak tube,CCD and all the electrical devices residing in a chamber to maintain themselves working at normal temperature and standard atmospheric pressure. The whole camera system is controlled by an embedded computer,which communicates through main control computer by Ethernet . The camera has a perfect security-lock system to ensure the safety of remote control and meets strict shielded requirement for EMI/EMP,which also has the ability of taking ultraviolet(UV) laser light introduced by optic fiber to build the absolute time fiducial for x-ray emission signal..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2871 (2009)
Design of Optical Balanced Bridge Current Transformer
Ma Rende, Wu Fuquan, Meng Xiangsheng, and Li Aiguo
In order to eliminate the effect to the optical current transformer by the liner birefringence which changes with the temperature,the idea of optical balanced bridge current transformer is advanced,and the principle is also given;analytical expression of azimuth angle variation is deduced that is produced by liner bireIn order to eliminate the effect to the optical current transformer by the liner birefringence which changes with the temperature,the idea of optical balanced bridge current transformer is advanced,and the principle is also given;analytical expression of azimuth angle variation is deduced that is produced by liner birefringence,the direction of 1/2 wave plate axis is also calculated which is used to eliminate the effect of the liner birefringence. The working principle and signal processing method of the optical balanced bridge are given,the expression that used to calculate the current is deduced. It is proved that the current transformer output error is within 2.96% when the temperature changes between 20 ℃ and 65 ℃ as the current is 2 A. The advancement of optical balanced bridge current transformer solved the problem of the effect to the system produced by the birefringence along with the variation of temperature which could not be solved using the traditional methods. This new method will boost the utility of optical current transformer..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2876 (2009)
Optical Devices
Intrinsic Frequency Response Extraction of Electroabsorption Modulators
Hasen Qiqige, Zhang Yun, Liu Yu, Xie Liang, and Zhu Ninghua
A new method for extracting intrinsic response of electro-absorption modulator is proposed,which is based on the analysis of modulation principle and equivalent circuit model. This method can simply remove the effects of the parasitic network、 test fixtures and optical detectors. We can get the accurate intrinsic respoA new method for extracting intrinsic response of electro-absorption modulator is proposed,which is based on the analysis of modulation principle and equivalent circuit model. This method can simply remove the effects of the parasitic network、 test fixtures and optical detectors. We can get the accurate intrinsic response of InGaAs/InAlAs electro-absorption modulator using our proposed technique..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2881 (2009)
Light Out-Coupling Efficiency in Flexible Organic Light-Emitting Devices
Xiong Zhiyong, Li Hongjian, Wang Junxi, Yuan Ming, Zhou Ziyou, and Li Xueyong
Based on the geometrical optics model,the expression of flexible organic light emitting devices (FOLED)′s out-coupling efficiency was presented. The influence of substrate curvature and its thickness,and organic layer′s refractive index on the performance of the FOLED′s out-coupling efficiency was studied,and the variaBased on the geometrical optics model,the expression of flexible organic light emitting devices (FOLED)′s out-coupling efficiency was presented. The influence of substrate curvature and its thickness,and organic layer′s refractive index on the performance of the FOLED′s out-coupling efficiency was studied,and the variation of out-coupling efficiency between FOLED and plane organic light emitting display (OLED) are contrasted as well. The result shows that:the out-coupling efficiency is enhanced with increased substrate curvature and its thickness,but is reduced with increased organic layer′s refractive index for outcurved substrate. The out-coupling efficiency is reduced with increased substrate curvature and thickness,and is also reduced with increased organic layer′s refractive index for incurvated substrate. The out-coupling efficiency of OLED is reduced with increased organic layer′s refractive index..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2885 (2009)
Dispersion Equalization of Four-Frequency Differential Laser Gyroscope with Non-Planar Resonator
Wang Zhiguo, Long Xingwu, and Wang Fei
In order to reduce drift caused by cavity variation,dispersion equalization of non-planar four-frequency differential laser gyro was investigated. Expression of DLG bias as a function of operating point and axial magnetic field was derived from classic theory of gas laser. Consequently the dispersion equalization was pIn order to reduce drift caused by cavity variation,dispersion equalization of non-planar four-frequency differential laser gyro was investigated. Expression of DLG bias as a function of operating point and axial magnetic field was derived from classic theory of gas laser. Consequently the dispersion equalization was proved theoretically. Coil around gain tube was used to provide axial magnetic field with controllable strength for gain medium,and piezoelectric transducer attached to cavity mirror was used to adjust cavity length or operating point. Afterwards,experimental curve of bias versus cavity length and coil current was obtained. The results showed that bias sensitivity to cavity-length change was a function of axial magnetic field,which was zero with Zeeman splitting of gain curve equal to nonreciprocal splitting. Dispersion equalization reduces drift caused by cavity variation,so it helps to improve DLG precision..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2892 (2009)
Physical Optics
Propagation Properties of Hollow Cone Double Gaussian Beams
Ling Ming, Dong Yuan, Cheng Liang, Ning Guobin, and Liang Zhu
A new mathematical model named hollow cone double Gaussian beams is set up. Based on mathematical model of hollow double-Gaussian beams and the initial light field intensity distribution,the analytical propagation formula for hollow cone double Gaussian beams through paraxial system was derived by use of Collins formulA new mathematical model named hollow cone double Gaussian beams is set up. Based on mathematical model of hollow double-Gaussian beams and the initial light field intensity distribution,the analytical propagation formula for hollow cone double Gaussian beams through paraxial system was derived by use of Collins formula under the cylindrical coordinates. Using the derived propagation formula,the controllable evolution properties of the intensity distribution of hollow cone double Gaussian beams in free space propagation were illustrated graphically at 1,10 and 60 m. After experenting with the biaxial crystal KNbO3,the hollow cone double Gaussian beams was obtained and the result,that the outer conic refraction angle of was equal to the convergence angle of the beams,was found. The experiment showed that the black spot areas in hollow beams increased with the transmission distance and the mathematical model of hollow cone double Gaussian beams was agreed to the experiment results basically. This research is significant for design of new laser hollow beams to generate the laser device based on hollow cone double Gaussian beams..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2920 (2009)
Quantum Optics
Experiment of Controllable Double-Well Optical Trap and Application of Asymmetric Double-Well Optical Trap
Li Yali, Wang Zhijian, Gong Tianlin, Zhang Hua, and Ji Xianming
The phase plates with different phase differences were fabricated according to the experimental scheme that used phase plates to generate controllable double-well optical traps. The diffraction intensity distributions of different phase plates and intensity distribution from double-well to single-well evolution processThe phase plates with different phase differences were fabricated according to the experimental scheme that used phase plates to generate controllable double-well optical traps. The diffraction intensity distributions of different phase plates and intensity distribution from double-well to single-well evolution process were measured. The experimental results showed good accordance with the theoretical results. Further analysis of the results revealed that the phase plates with Δφ≠π can generate asymmetric double-well optical traps. This has important applications in atomic optics experiment and develops their application range..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2924 (2009)
Thin Films
Study and Fabrication of Visible and IR Dual-Band Broadband Antireflection Coating
He Caimei, Fu Xiuhua, Zhang Jiabin, and Li Shan
In order to meet the military instruments′ operating requirements,An antireflection coating on the substrate of ZnS at 400-1000 nm (visible and near infrared band) and 7-11 μm (far infrared band) is deposited,it requires a average transmittance over 90%. Electronic beaming vacuum depositing method is adopted with the aIn order to meet the military instruments′ operating requirements,An antireflection coating on the substrate of ZnS at 400-1000 nm (visible and near infrared band) and 7-11 μm (far infrared band) is deposited,it requires a average transmittance over 90%. Electronic beaming vacuum depositing method is adopted with the aid of ion assistant deposition systems as well as chose ZnS as the material of high refractive index and YbF3 as the material of low refractive index. Using three modular processing systems of the latest optilayer software as assistance,optimizing technical parameters,and improving monitor method,reducing thickness error,antireflection coating on the substrate of ZnS to achieve the requirements have be deposited. The average transmittance exceeds 91% through 400-1000 nm wavelength. Moreover,it makes the transmittance over 90% through 7-11 μm wavelength. In addition,the film can resist harsh environment and completely meet the demands of military optical instruments..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2929 (2009)
Photoluminescence of Amorphous Niobium Oxide Film in Visible Light Area
Tao Shufeng, and Zhou Xiaofeng
Niobium oxide amorphous films were deposited on silicon substrates at temperatures ranging from 200-300 ℃ by heating a pure niobium foil in a rough vacuum. The films were amorphous in structure and with morphology of vertically aligned nanocolumniations. This structure after anealing is of interesting photoluminescenceNiobium oxide amorphous films were deposited on silicon substrates at temperatures ranging from 200-300 ℃ by heating a pure niobium foil in a rough vacuum. The films were amorphous in structure and with morphology of vertically aligned nanocolumniations. This structure after anealing is of interesting photoluminescence property in the visible light range. The curve of emission intensity with annealing temperature of films was given. The mechanism for this photoluminescence (PL) behavior of the amorphous niobium oxide films was also investigated and discussed;the changed power PL experiment having supported the result forcefully..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2934 (2009)
Influence of Substrate Temperature on the Structure and Band Edge Luminescence of ZnO Thin Films
Zhang Dong, Wang Changzheng, and He Ying
Zinc oxide films are deposited on silicon substrate by reactive pulsed laser deposition of zinc target. The effect of substrate temperatures on the crystal and band edge luminescence is studied using X-ray diffraction,scanning electron microscopy,Raman spectra and photoluminescence. The results show that the films depoZinc oxide films are deposited on silicon substrate by reactive pulsed laser deposition of zinc target. The effect of substrate temperatures on the crystal and band edge luminescence is studied using X-ray diffraction,scanning electron microscopy,Raman spectra and photoluminescence. The results show that the films deposited at 300 ℃ had the highest c-axis preferred orientation,and with increase of the substrate temperature the full width of half maximum decreases,and the grain size increases. The films deposited at 400 ℃ have the equiaxed crystallites. Meanwhile,the result of Raman spectra shows that the defects in films deposited at various substrate temperature has no obvious differene,and exhibits tensile strain which is the smallest in the films deposited at 400 ℃. The films deposited at 400 ℃ exhibits most intense UV emission and the weakest green-yellow emission. Therefore,the equiaxed crystallites can improve the photoluminescence property with less defects and tensile strain in the films..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 29, Issue 10, 2938 (2009)
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