Contents
2017
Volume: 37 Issue 5
45 Article(s)
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Atmospheric Optics and Oceanic Optics
Comparison of Two Approaches for Estimating Atmospheric Optical Turbulence Intensity near Sea
Lü Jie, Zhu Wenyue, Cai Jun, and Qing Chun
A refractive index structural constant C2n and three kinds of conventional meteorology parameters (temperature, wind speed and relative humidity) are chosen from ship-based measurement in Sanya from 2016-01-06 to 2016-01-09. Two models are established based on the backward propagation neural network and the stepwise reA refractive index structural constant C2n and three kinds of conventional meteorology parameters (temperature, wind speed and relative humidity) are chosen from ship-based measurement in Sanya from 2016-01-06 to 2016-01-09. Two models are established based on the backward propagation neural network and the stepwise regression theory, and three-day estimation of C2n is carried out. The results show that the variation tendency and magnitude of the results estimated by two models are in accord with general characteristics and change rule of the optical turbulence near the sea, and these results demonstrate the fundamental diurnal variation of C2n. Overall correlation coefficients are 0.8661 and 0.8496. Statistical variables of mean absolute error, mean relative error, root mean square variance and relative coefficient are used to evaluate the estimation results. Further analysis shows that both the two models can calculate C2n near the sea precisely. However, when weak turbulence occurs at night, the estimation results are slightly higher than measurement results. To further improve the estimation accuracy, the estimation effect during nighttime should be improved..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 501001 (2017)
Flue Gas Mercury Online Monitoring System Based on Transverse Zeeman Effect
Zhang Yong, Si Fuqi, Li Chuanxin, Zeng Yi, Liu Wenqing, and Zhou Haijin
In order to solve the problem of coal flue gas mercury monitoring, an online monitoring system for flue gas mercury is established based on transverse Zeeman effect. When a mercury lamp is placed in magnetic field with magnetic induction intensity of 1.5 T, the resonant absorption line at 253.65 nm is split into π and In order to solve the problem of coal flue gas mercury monitoring, an online monitoring system for flue gas mercury is established based on transverse Zeeman effect. When a mercury lamp is placed in magnetic field with magnetic induction intensity of 1.5 T, the resonant absorption line at 253.65 nm is split into π and σ± linearly polarized light because of Zeeman Effect. Mercury atom can absorb π linearly polarized light but can not absorb σ± linearly polarized light, so the system can realize the accurate correction for interference background including the interference gases, particulate matter and so on. The low detection limit of this system is 66.3 ng/m3. The mercury detection is not affected when the volume fraction of NO2 gas is not larger than 5.09×10-4 and the volume fraction of SO2 gas is not larger than 1.83×10-4. The monitoring for flue gas mercury in coal-fired power plant lasts 8 days. The average mass concentration of 8.3 μg/m3 and maximum mass concentration of 19.4 μg/m3 of flue gas mercury are obtained, and they are lower than that in national standard. The experimental results show that the flue gas mercury online monitoring system can realize accurate correction for background interference which is caused by interference gases and particulate matter, and realize accurate measurement for flue gas mercury. The system is proper to be used for long-term online monitoring of flue gas mercury..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 501002 (2017)
Carbon Dioxide Retrieval Method Based on Statistics and Optical Path Distribution
Duan Fenghua, Wang Xianhua, Ye Hanhan, Jiang Yun, and Wu Hao
In order to study climate change, high-precision measurement for carbon dioxide (CO2) by remote sensing satellite needs to be achieved. Scattering of aerosol and thin cirrus with high transmittance is the main environmental factor which affects CO2 retrieval precision. We combine statistical method of principal componeIn order to study climate change, high-precision measurement for carbon dioxide (CO2) by remote sensing satellite needs to be achieved. Scattering of aerosol and thin cirrus with high transmittance is the main environmental factor which affects CO2 retrieval precision. We combine statistical method of principal component analysis (PCA)with optical path probability density distribution function (PPDF). Priori values for CO2 retrieval can be obtained by PCA method, and large deviation which causes the problem that calculation results deviate from the truth value can be avoided. We also use three-layer PPDF model to approach the change of absorption spectral lines caused by variation of photon path because of scattering of thin cirrus and aerosol. The results show that the combination of PCA method and PPDF method improves the retrieval precision significantly. From the retrieval results of GOSAT data in Taklamakan desert in 2013, we can find that the variance is 3.5 by PPDF method, while the combination of two methods can obtain the variance of 1.4, which is superior to the variance of 1.6 provided by NIES.然科学基金青年科学基金(４１６０１３９３).
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 501003 (2017)
Detectors
Error Analysis of Infrared Temperature Measurement for 3D Non-Isothermal Porous Layer
Li Yang, Xia Xinlin, Fan Chao, Chen Xue, and Tan Heping
In the application of solar porous receivers, a numerical 3D model for infrared temperature measurement of non-isothermal porous layer with anisotropic scattering is developed based on the reverse Monte Carlo method. The effects of scattering event, layer thickness, material emissivity, porosity and pore diameter on thIn the application of solar porous receivers, a numerical 3D model for infrared temperature measurement of non-isothermal porous layer with anisotropic scattering is developed based on the reverse Monte Carlo method. The effects of scattering event, layer thickness, material emissivity, porosity and pore diameter on the measurement error are investigated. A procedure to calculate the surface temperature of porous materials is proposed. The results show that a notable error occurs between the detected temperature from the infrared camera and the surface temperature of porous materials. Backward scattering weakens the effect of background radiation, which brings smaller error at high temperatures and larger error at low temperatures. The measurement error increases rapidly with a high porosity (higher than 0.93). The parameters with measurement error less than 2% are as follows: the porous layer thickness is 14-27 mm, the material emissivity is 0.33-0.81, the porosity is 0.86-0.93 and the pore diameter is 1.5-2.8 mm..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 504001 (2017)
Diffraction and Gratings
Fast Simulation Method of Extreme-Ultraviolet Lithography 3D Mask Based on Variable Separation Degration Method
Zhang Heng, Li Sikun, and Wang Xiangzhao
A fast simulation method based on variable separation is proposed for 3D mask diffraction in extreme-ultraviolet lithography (EUVL). The method achieves higher simulation speed while maintaining a good simulation accuracy. In this method, the 3D mask is decomposed into two orthogonal 2D masks. The diffraction spectrum A fast simulation method based on variable separation is proposed for 3D mask diffraction in extreme-ultraviolet lithography (EUVL). The method achieves higher simulation speed while maintaining a good simulation accuracy. In this method, the 3D mask is decomposed into two orthogonal 2D masks. The diffraction spectrum simulation on two 2D masks are carried out through rigorous electromagnetic method. The results are then multiplied to reconstruct the three-dimensional diffraction spectrum. We set a premise of 6° main incident angle, 45° linearly polarized light illumination and 22 nm 3D square contact hole mask. Azimuth angle is ranging from 0° to 90°. Under the same simulation parameters, the simulation results of this method are compared with the rigorous simulation results of commercial lithography simulation software Dr.LiTHO. The errors of the simulated critical-dimension of the proposed method are within 0.21 nm, and the simulation speed is about 65 times faster. Under the above parameters, the proposed method is compared with the domain decomposition method of Dr.LiTHO and a fast method based on mask-structure decomposition. The results show that the simulation accuracy and speed are improved more than double. The method needs no calibrations for model parameters and suits fast simulations of 3D masks that contain rectangular patterns..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 505001 (2017)
Fiber Optics and Optical Communications
Multiple-Input Multiple-Output Channel Decorrelation Technique for Visible Light Communication Based on Normal Vector Tilting
Zhang Haiyong, Zhu Yijun, and Zhang Yanyu
In visible light communication multiple-input multiple-output (VLC-MIMO) system, the increasing of sender and receiver elements, the decreasing of array element space, and the increasing of transmission distance cause a series problems of serious interference on receiver of the system and lack of channel matrix, and fuIn visible light communication multiple-input multiple-output (VLC-MIMO) system, the increasing of sender and receiver elements, the decreasing of array element space, and the increasing of transmission distance cause a series problems of serious interference on receiver of the system and lack of channel matrix, and further lead to low reusing rate of the system and large channel correlation. To solve these problems, the minimizing of interference-to-signal ratio is taken as the optimization goal. The channel model of VLC-MIMO is established, and the effects of the normal vector tilting angles of sender and receiver elements on channel correlation are analyzed. The normal vector tilting angle of light-emitting diode is optimized to decrease the channel correlation, and the optimal tilting angle of the normal vector tilting angle of each LED is obtained. By comparing the illumination distribution on the receiving plane of the system, we find that the proposed scheme can effectively reduce the interference, and the bit error rate is reduced by 42 dB compared with that of the link-blocked system..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 506001 (2017)
Characteristics of Modulation Transfer Function of Pixel Coupling Between Array Fiber Image Bundles and Array CCD
He Xu, Yuan Li, Jin Chunqi, and Zhang Xiaohui
For the advancements of imaging fiber bundle fabrication technology with high resolution, traditional high-performance photoelectric imaging instruments become flexible with greatly reduced volume and weight. However, traditional image quality evaluation models are limited by the pixel coupling discrete sampling effectFor the advancements of imaging fiber bundle fabrication technology with high resolution, traditional high-performance photoelectric imaging instruments become flexible with greatly reduced volume and weight. However, traditional image quality evaluation models are limited by the pixel coupling discrete sampling effect of array fiber image bundles and array CCD. On the basis of the transfer process of grayscale cosine distribution optical signal in array fiber image bundles and array CCD, a mathematical model of coupled modulation transfer function (Coupled-MTF) for coupled discrete sampling system is established. Results show that the coupled-MTF converges to a fixed value when the deviation between an input signal spatial frequency and Nyquist frequency is 1% and the total number of pixels in the array is more than 1000. A small frequency deviation corresponds to a slow convergence velocity of the coupled-MTF oscillation. The oscillation amplitude of coupled-MTF differs in tangential and sagittal directions in a manner related to the corresponding pixel coupling deviation. The coupled-MTF periodically oscillates with the coupling deviation between the array fiber image bundles and the array CCD. One cycle is equivalent to the diameter of fiber cladding. The results show that the coupled-MTF shows different characteristics from the modulation transfer function of classical space invariant imaging system..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 506002 (2017)
Constant Pressure Fiber Attenuated Total Reflection Probe Used in Infrared Spectrum Analysis
Qu Ruoyuan, Hou Liping, Feng Xiang, Wang Zhiji, Wu Kan, Zou Weiwen, and Chen Jianping
A constant pressure fiber attenuated total reflection (ATR) probe which can be used in infrared spectrum analysis and in situ nondestructive testing is developed. Combined with constant pressure inhabiting device, the probe contacts with the sample under constant positive pressure based on ATR technique. It can signifiA constant pressure fiber attenuated total reflection (ATR) probe which can be used in infrared spectrum analysis and in situ nondestructive testing is developed. Combined with constant pressure inhabiting device, the probe contacts with the sample under constant positive pressure based on ATR technique. It can significantly improve test repeatability of sample absorption spectra, and the multiple measurement error is less than 5%. The probe is used to analyze the stabilizer mass fraction in nitrate ester plasticized polyether (NEPE) propellant. The measurement results are in agreement with previous reports, and it can greatly improve the measurement convenience. The developed probe can be widely used in the occasions where the material has to be carried on nondestructive test repeatedly..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 506003 (2017)
Image Processing
Local Hypergraph Laplacian Regularized Low-Rank Representation for Noise Reduction of Hyperspectral Images
Xue Zhixiang, Yu Xuchu, Tan Xiong, and Fu Qiongying
Low-rank representation is one of the state-of-art hyperspectral image denoising algorithms, but it suffers from ignoring the high-order relations between data points in images. We propose a hypergraph Laplacian regularized low-rank representation algorithm for noise reduction of hyperspectral images, which can represeLow-rank representation is one of the state-of-art hyperspectral image denoising algorithms, but it suffers from ignoring the high-order relations between data points in images. We propose a hypergraph Laplacian regularized low-rank representation algorithm for noise reduction of hyperspectral images, which can represent the high-order relations between data points by using the hypergraph Laplacian regularization. The ability of maintaining the local information is improved, and the sparse and non-negative constraints are added to the model coefficient matrix. The proposed method not only resumes the low-rank signal components, but also represents the high-order relations of the image data. Experimental results on AVIRIS and ProSpecTIR-VS images show that the proposed approach can maintain the spatial and spectral information of images better, which improves the denoising results of hyperspectral images effectively..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 510001 (2017)
A Laminar Denoising Algorithm for Depth Image
Tan Zhiguo, Ou Jianping, Zhang Jun, and He Jie
Conventional denoising methods cannot deal with much noise in depth images, which are acquired by time-of-flight or structured light depth sensors. So, a laminar denoising algorithm is proposed in this paper, which evaluates the noise level of the image, and depth image laminas are acquired with established depth laminConventional denoising methods cannot deal with much noise in depth images, which are acquired by time-of-flight or structured light depth sensors. So, a laminar denoising algorithm is proposed in this paper, which evaluates the noise level of the image, and depth image laminas are acquired with established depth laminar level according to noise level. Then, noises and holes are removed in every lamina. At last, all laminar images are combined into a whole depth image. Experimental results demonstrate that the proposed algorithm can not only remove the uncertain interferential noise, but also maintain the original detail and edges of objects in the depth images..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 510002 (2017)
Imaging Systems
Research on Pseudo-Thermal Source of X-Ray Fourier-Transform Ghost Imaging
Zhao Xin, Yu Hong, Lu Ronghua, Tan Zhijie, Han Shensheng, and Cao Qing
High quality pseudo-thermal sources are essential in X-ray ghost imaging microscopic applications. The pseudo-thermal source used in X-ray Fourier-transform ghost imaging is obtained by modulating X-ray with a screen full of randomly distributed holes. The statistical properties of the X-ray speckle fields are analyzedHigh quality pseudo-thermal sources are essential in X-ray ghost imaging microscopic applications. The pseudo-thermal source used in X-ray Fourier-transform ghost imaging is obtained by modulating X-ray with a screen full of randomly distributed holes. The statistical properties of the X-ray speckle fields are analyzed based on the statistical optics, and the influence of the screen parameters is explored by numerical simulations. Results show that the optimum contrast for ghost imaging can be achieved when the phase difference introduced by the screen is π. For random amplitude screens, the imaging contrast increases with the decrease of the duty cycle, while for random phase screens, the imaging contrast decreases with the decrease of the duty cycle. In practical X-ray Fourier-transform ghost imaging systems, the screen made of metal can be treated as a complex amplitude screen, and the high-contrast ghost imaging can be realized by choosing appropriate transmittance and duty cycle of the screen..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 511001 (2017)
Depth-Dependent Dispersion Compensation for Optical Coherence Tomography
Pan Liuhua, Li Zhongliang, Wang Xiangzhao, Zhang Xiangyang, Nan Nan, Chen Yan, Wang Xuan, and Lu Yu
A depth-dependent dispersion compensation method is presented to enhance the axial resolution in Fourier-domain optical coherence tomography. The dispersion compensation coefficients at different depths are calculated by an iterative algorithm, and a mathematical expression between the dispersion compensation coefficieA depth-dependent dispersion compensation method is presented to enhance the axial resolution in Fourier-domain optical coherence tomography. The dispersion compensation coefficients at different depths are calculated by an iterative algorithm, and a mathematical expression between the dispersion compensation coefficient and depth is obtained through numerical calculation. From the mathematical expression, the dispersion compensation coefficients at different depths are calculated to eliminate the high-order dispersion phase at different depths. The dispersion mismatch between the reference arm and sample arm is compensated and the broadening effect of dispersion is avoided. Theoretical derivation and experimental results in the optical coherence tomography systems show that the dispersion at different depths, including the deeper positions which have weaker signals, is effectively compensated by the depth-dependent dispersion compensation method and thus more structure informations of the sample are obtained..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 511002 (2017)
Three-Dimensional Imaging of Optical Projection Tomography Based on Normalized Dynamic Range-Transform
Wang Jielin, Liao Riwei, Zeng Yaguang, Xiao Hua, and Tang Zhilie
The dynamic range and exposure time of the camera are the main limitation for the traditional optical projection tomography to achieve the intact and detailed three-dimensional information of samples with complicated spatial structure. The normalized dynamic range-transform of three-dimensional imaging acquisition and The dynamic range and exposure time of the camera are the main limitation for the traditional optical projection tomography to achieve the intact and detailed three-dimensional information of samples with complicated spatial structure. The normalized dynamic range-transform of three-dimensional imaging acquisition and process are used to solve the existing conundrum of traditional three-dimensional imaging based on the optical projection tomography technology, by means of setting the Lambert source and carrying on the new method of normalized dynamic range-transform. Setting multiple exposures to get the image of sample, normalizing the tested response curve of the camera for solving the non-linear distortion and false appearance existing in the traditional high dynamic range, using the image fusion theory to improve the image processing program, then reconstructing the sample by the reverse projection algorithm, and get the three-dimensional structure of the sample finally. From the analysis of imaging result, the normalized dynamic range-transform of three-dimensional imaging acquires more information of samples with complicated spatial structure, more details of different areas are able to be observed through this way..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 511003 (2017)
Hyperspectral Camera Based on Ghost Imaging via Sparsity Constraints with Application of Flat-Field Grating
Liu Shengying, Liu Zhentao, Wu Jianrong, Li Enrong, Tan Shiyu, Shen Xia, and Han Shensheng
A spectral camera based on the ghost imaging via sparsity constrains acquires a three-dimensional spatial-spectral data cube of information about a target in a single exposure. However, the spectral resolution and signal-to-noise ratio are limited, since the speckle field with different wavelengths are at the same locaA spectral camera based on the ghost imaging via sparsity constrains acquires a three-dimensional spatial-spectral data cube of information about a target in a single exposure. However, the spectral resolution and signal-to-noise ratio are limited, since the speckle field with different wavelengths are at the same location in the detector. To deal with these issues, a system which utilizes a flat-field grating to disperse the optical fields with different wavelengths in the detector to realize hyperspectral camera based on the ghost imaging via sparsity constraints is demonstrated. Through theoretical derivation of the imaging process, the correlation function of the system is obtained, and the derived result is verified by the experiments and numerical simulations. Under guaranteeing the advantages of previous ghost imaging spectral camera spectral camera, the proposed system can modulate the spatial and spectral resolution separately, meanwhile, the signal-to-noise ratio becomes controllable. Additionally, the measurement matrix will be better optimized according to the characteristics of optical fields with different wavelengths to improve the quality of imaging in the future..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 511004 (2017)
Instrumentation, Measurement and Metrology
Testing Device Based on Interferometric Ballistic Pendulum and Its Double Precision Data Processing Method
Jin Yunsheng, Zhang Xingwei, Tan Fuli, Zhao Jianheng, Sun Chengwei, and Yang Hua
The laser interferometry is employed in the ballistic pendulum measurement, and the main uncertainties of measurement are analyzed. In the measurement process, the corresponding treatment methods are provided. A new set of independent complementary data processing methods is added on the basis of the original method thThe laser interferometry is employed in the ballistic pendulum measurement, and the main uncertainties of measurement are analyzed. In the measurement process, the corresponding treatment methods are provided. A new set of independent complementary data processing methods is added on the basis of the original method that calculates the maximum swing angle with the accumulated peak amount. The combination of these two methods has the double precision test effect and can expand the applicable scope and improve the measurement credibility..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 512001 (2017)
Attitude and Angular Speed Estimation of Spacial Objects Based on Photometric Observation
Shan Bin, Liang Yongqi, and Li Hengnian
The photometric measuring model of spacial objects is established based on the shape reflection of the objects and the motion relationship among the sun, the earth and the spacial objects. The effects of the attitude, the angular speed, and the object shape on the photometric measuring data are analyzed. The kinematic The photometric measuring model of spacial objects is established based on the shape reflection of the objects and the motion relationship among the sun, the earth and the spacial objects. The effects of the attitude, the angular speed, and the object shape on the photometric measuring data are analyzed. The kinematic model related to the attitude angle and the angular speed of the objects is established which realizes the joint estimation of the attitude and the angular speed, and the adaptive estimation capability of the algorithm is discussed. The simulation results shows that the photometric observation scheme can realize the joint estimation of unknown attitudes and angular speeds. The algorithm has an adaptive estimation ability when the attitude and the angular speed change slowly. However, with the increase of the side face number, the estimation errors of attitude and angular speed increase and the convergence rate of this algorithm decreases..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 512002 (2017)
Lasers and Laser Optics
Adaptive Adjusting Technique of Thermal Effect to Laser Beam Quality
Qu Pengfei, Wang Shiyu, Guo Zhen, Cai Defang, and Li Bingbin
Spatial distributions of pump beam and oscillating beam will be affected by thermal effect in solid state laser. The research shows that a specific pump power region is existed in end-pumped solid state laser. In this interval, pump beam and fundamental mode oscillating beam achieve large overlap in the gain medium undSpatial distributions of pump beam and oscillating beam will be affected by thermal effect in solid state laser. The research shows that a specific pump power region is existed in end-pumped solid state laser. In this interval, pump beam and fundamental mode oscillating beam achieve large overlap in the gain medium under thermal effect, which results in higher efficiency of pump source and better beam quality of laser. Based on the characteristic, a laser is designed. Spatial distributions between pump beam and fundamental mode oscillating beam of the laser can achieve large overlap, and the beam quality factor is lower than 2.3 with pumping power ranging from 105 W to 115 W. Out of this range, the beam quality rapidly increases to more than 3. A new optimization algorithm is proposed to calculate the pump power region, which can find ideal pump power region rapidly in end-pumped solid state laser. Compared with the experiment, the pump power region of the proposed method achieves a higher level of compliance with experimental region, and the relative error is less than 5% with high reliability..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 514001 (2017)
1.5 μm Fiber Ethane Gas Raman Laser Amplifier
Chen Yubin, Wang Zefeng, Gu Bo, and Lu Qisheng
A 1.5 μm fiber gas Raman laser amplifier based on the hollow core fibers is reported. In the experiments, a 1.5 μm tunable distributed feed back laser is used as a seed. The output continuous wave seed laser, together with the output pulse pump laser of a 1064 nm microchip laser, is coupled into the ethane-filled holloA 1.5 μm fiber gas Raman laser amplifier based on the hollow core fibers is reported. In the experiments, a 1.5 μm tunable distributed feed back laser is used as a seed. The output continuous wave seed laser, together with the output pulse pump laser of a 1064 nm microchip laser, is coupled into the ethane-filled hollow core fiber by using a dichroic mirror, and then efficiently generated 1553 nm Raman laser by stimulated Raman scattering of ethane gas. With the injected seed laser, the Raman scattering threshold is significantly decreased and the Raman conversion efficiency increases to 47.5%. This study provides an effective technical avenue to achieve the efficient fiber gas Raman laser output..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 514002 (2017)
Dual Concentration Doped Nd∶YAG Composite Ceramic Slab Laser with High Power
Li Mi, Hu Hao, Gao Qingsong, Wang Juntao, Zhang Jian, Wu Yingcheng, Chen Xiaoming, Zhou Tangjian, Xu Liu, Tang Chun, Zhao Na, Liu Peng, and Xu Xiaoxiao
A Nd∶YAG composite ceramic slab end-pumped with diode is designed theoretically, and a dual concentration doped Nd∶YAG composite ceramic slab is fabricated. The extracted power after double-pass amplification is 7.08 kW when the total pumping power of diode is 18.06 kW, the optical-optical conversion efficiency is up tA Nd∶YAG composite ceramic slab end-pumped with diode is designed theoretically, and a dual concentration doped Nd∶YAG composite ceramic slab is fabricated. The extracted power after double-pass amplification is 7.08 kW when the total pumping power of diode is 18.06 kW, the optical-optical conversion efficiency is up to 39.2%, and the depolarization of single-pass transmission is about 3.2%. The experimental results show that the Nd∶YAG composite ceramic slab has significant effect on enhancing the output power and reducing the depolarization of the slab laser..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 514003 (2017)
Machine Vision
Multi-Scale Correlation Filtering Tracker Based on Adaptive Feature Selection
Shen Qiu, Yan Xiaole, Liu Linfeng, Kong Fanqiang, and Wang Dandan
Recently, the correlation filter-based trackers have aroused increasing interest because of their good performance and high efficiency. A multi-scale correlation filtering tracker based on adaptive feature selection is presented. Firstly, we extract three complementary features to learn three independent filter models.Recently, the correlation filter-based trackers have aroused increasing interest because of their good performance and high efficiency. A multi-scale correlation filtering tracker based on adaptive feature selection is presented. Firstly, we extract three complementary features to learn three independent filter models. By comparing the response maps, we evaluate the tracking performance of each feature, and then adaptively select the most representative feature for tracking. Secondly, to better handle occlusions and drifts, we improve the online model update strategy by setting peak response threshold as a criterion. Furthermore, we learn a separate filter model for scale estimation. The experimental results show that the proposed tracker achieves better accuracy compared with state-of-the-art correlation filter-based trackers and other popular trackers when running at 53.12 frame/s..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 515001 (2017)
A Calibration Method of Focused Light Field Cameras Based on Light Field Images
Sun Junyang, Sun Jun, Xu Chuanlong, Zhang Biao, and Wang Shimin
In the three-dimensional depth reconstruction of the scene based on light field photography, it is necessary to calibrate the geometric parameters of light field cameras. In this paper, a calibration method of focused light field cameras is proposed based on Jiangsu raw light field images. The raw light field images ofIn the three-dimensional depth reconstruction of the scene based on light field photography, it is necessary to calibrate the geometric parameters of light field cameras. In this paper, a calibration method of focused light field cameras is proposed based on Jiangsu raw light field images. The raw light field images of a calibration board with different orientations are captured. According to the conjugation relationship between image points and virtual image points (conjugation points of image points for the microlens), the coordinates of the virtual image points are calculated. The calibration model of focused light field cameras is established according to the conjugation relationship between the corner points on the calibration board and the virtual image points. The model is then solved by Levenberg-Marquardt algorithm. Calibration experiments are carried out. The accuracy of the proposed method is compared to that of the calibration method based on the total focused images. Experimental results show that the error between the virtual image points obtained from raw light field images and those (conjugation points of corner points for mainlens) from total focused images is less than 21 pixels. The relative calibration errors of the corner points are less than 3%. The calibrated configuration parameters and external parameters from raw light field images are in good consistence with those from total focused images. The proposed method is proved to be effective calibrating the focused light field cameras..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 515002 (2017)
Real-Time Panoramic Imaging Method for Train-Borne Forward Motion Video
Jiang Xinlan, Wang Shengchun, Luo Siwei, Huang Yaping, and Dai Peng
In the traditional video mosaic model and image alignment method, the time-consuming image matching and complicated optical flow computation are the performance bottleneck of real-time mosaic. A real-time panorama imaging method is proposed, which makes use of the geometric structure of the physical scene and the motioIn the traditional video mosaic model and image alignment method, the time-consuming image matching and complicated optical flow computation are the performance bottleneck of real-time mosaic. A real-time panorama imaging method is proposed, which makes use of the geometric structure of the physical scene and the motion information of the train to construct the mosaic region of the video and establishes the geometric model to achieve the alignment of the mosaic region. The entire stitching avoids the complex image processing, realizes the railway panorama real-time acquisition and also provides a lightweight video panoramic index method, which reduces the storage and access cost of the video data..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 515003 (2017)
3D Reconstruction Based on Horopter
Wang Shan, and Xu Xiao
A simple three-dimensional (3D) reconstruction algorithm is designed based on the rule of horopter and the theory of binocular stereo vision. The optical axes of the two cameras to shoot the same object are cross-placed. The image pixel coordinates are changed into spherical coordinates. The feature points are matched A simple three-dimensional (3D) reconstruction algorithm is designed based on the rule of horopter and the theory of binocular stereo vision. The optical axes of the two cameras to shoot the same object are cross-placed. The image pixel coordinates are changed into spherical coordinates. The feature points are matched in spherical coordinates domain and the precise points are gotten by curve fitting. Finally, we turn the points to space coordinates, and obtain the 3D model of the target object. Experimental results show that this matching algorithm can accurately determine the location of the target object, and it has low computing complexity. The data processing of the later stage adopts the method of piecewise fitting so that the points on the 3D model of the target object obtained after the coordinate transformation distribute accurately and densely..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 515004 (2017)
Distractor-Aware Object Tracking Based on Multi-Feature Fusion and Scale-Adaption
Li Shuangshuang, Zhao Gaopeng, and Wang Jianyu
Aiming at the tracking drift problem caused by the RGB feature, similar appearance and scale change in complex scenes, an improved method of distractor-aware object tracking based on multi-feature fusion and scale-adaption is proposed. Firstly, the distractor-aware object models are established base on the RGB feature Aiming at the tracking drift problem caused by the RGB feature, similar appearance and scale change in complex scenes, an improved method of distractor-aware object tracking based on multi-feature fusion and scale-adaption is proposed. Firstly, the distractor-aware object models are established base on the RGB feature and the modified (histogram of oriented gradient) HOG feature, which are extracted from object, surrounding background, and distractors. Secondly, the candidates are extracted by dense sampling in likelihood maps, which are obtained by calculating every pixel in the search region. The locations of the target and the distractor are obtained by vote score and distance score, also the model updating method is given. The RGB feature is extracted to establish a model scale, and the multi-scale feature pyramid method is used to get templates at different scales. The optimal scale is obtained by comparison between the model scale and the template scales. The experimental results indicate that the proposed algorithm can well adapt to environmental variation including distractors, partially blocking and scale variation and outperforms the compared tracking methods in terms of the distance precision and overlap precision..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 515005 (2017)
Center Extraction Method for Star-Map Targets Based on Anisotropic Gaussian Surface Fitting
Wang Min, Zhao Jinyu, and Chen Tao
The star and satellite target detection and recognition are one of the important applications of space surveillance system. Because of the characteristic of point target imaging of the map image, and a large number of the interference of background stars, the feature extraction of the map for target recognition is diffThe star and satellite target detection and recognition are one of the important applications of space surveillance system. Because of the characteristic of point target imaging of the map image, and a large number of the interference of background stars, the feature extraction of the map for target recognition is difficult, so the location of the object is the key characteristics to realize target identification. Gaussian curved surface fitting method is one of the target centroid extraction algorithms to be used widely. Theoretical analysis and experiment show that the traditional Gaussian curved surface fitting method of the satellite motion poisoning has much error. So, the anisotropic Gaussian surface fitting model is put forward, and the model by using two different Gaussian blur parameters and rotation factors to capture target of anisotropic characteristics of different directions, which is suitable for the fuzzy random direction caused by the satellite movement. Simulation experiments and real data test show that the overall positioning accuracy of this method can achieve 0.008 and 0.04, respectively, which is able to accurately extract the map target centroid, and improved greatly than that of the traditional methods..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 515006 (2017)
Materials
Photoluminescence Properties of K1-xSr4(BO3)3∶xPr3+ Phosphors Prepared by High-Temperature Solid-State Method
Ma Shizhang, Feng Wenlin, and Peng Zhiqing
Luminescent materials of K1-xSr4(BO3)3∶xPr3+ are successfully prepared with the high-temperature solid-state method. The X-ray diffraction patterns show that the synthesized sample has a symmetrical structure of Ama2 space point group. The scanning electron microscopy analysis results show that the sample has good dispLuminescent materials of K1-xSr4(BO3)3∶xPr3+ are successfully prepared with the high-temperature solid-state method. The X-ray diffraction patterns show that the synthesized sample has a symmetrical structure of Ama2 space point group. The scanning electron microscopy analysis results show that the sample has good dispersion degree and crystallinity although its appearance is irregular and fluffy. When the doped mole fraction of Pr3+ is 1%, the light intensity of the sample reaches the maximum. The absorption and diffuse reflection spectra are well enantiomorphous with excitation and emission spectra..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 516001 (2017)
First-Principles Study of Electronic Structure and Optical Property of AlN1-xPx Alloys
Hou Jiahui, He Dafang, Chen Jingjing, Li Chunmei, and Cheng Nanpu
Based on the plane-wave ultra-soft pseudo-potential in the first-principles of density functional theory and by using the generalized gradient approximation and the Heyd-Scuseria-Ernzerhof 03 (HSE03) method to correct the energy bands and density of states, the crystal structure, the electronic structure and the opticaBased on the plane-wave ultra-soft pseudo-potential in the first-principles of density functional theory and by using the generalized gradient approximation and the Heyd-Scuseria-Ernzerhof 03 (HSE03) method to correct the energy bands and density of states, the crystal structure, the electronic structure and the optical property of AlN1-xPx (x=0, 0.25, 0.50, 0.75, 1) alloys are studied. The results show that the lattice constant of AlN1-xPx alloys increases linearly as the P component increases. AlN1-xPx (x=0, 0.25, 0.75, 1) alloys are of the cubic system, while AlN0.50P0.50 alloy belongs to the tetragonal system. The band gap of AlN1-xPx alloys firstly decreases and then increases as the P component increases. AlN and AlP alloys are the indirect band gap semiconductors, while AlN1-xPx (x=0.25, 0.50, 0.75) alloys belong to the direct band gap semiconductors. The presence of P destroys the original eigenvalues and the degenerate states of AlN, and changes the electronic band structures. As the P component increases, the optical characteristic curves of AlN1-xPx move towards the low energy region, and the subsidiary strong peaks of the imaginary parts of dielectric functions gradually fade away. AlN1-xPx alloys can absorb the ultraviolet light strongly and the presence of P can broaden the absorption region of visible light..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 516002 (2017)
Microscopy
Development of Compact Spectrally Encoded Microscopy Imaging System
Liao Jiuling, and Gao Wanrong
Spectrally encoded microscopy uses a diffraction grating and a spectrum analysis setup to obtain microscopic images. The different positions on the sample are illuminated by different wavelengths. Then the spatial information is obtained by decoding the spectrum of reflection light. In this paper, a compact spectrally Spectrally encoded microscopy uses a diffraction grating and a spectrum analysis setup to obtain microscopic images. The different positions on the sample are illuminated by different wavelengths. Then the spatial information is obtained by decoding the spectrum of reflection light. In this paper, a compact spectrally encoded microscopy (CSEM) is developed based on a swept source and a balanced detection. A fixed gain balanced detector is employed in the system to detect the weak sample light without amplifier. The lateral resolution of the system is measured by imaging a 1951USAF resolution test target. The imagings of excised swine small intestine and the finger skin in vivo are obtained to verify the imaging performance of biological tissue. The results show that the CSEM has the capability of generating depth-resolved imaging of biological tissue..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 518001 (2017)
Nonlinear Optics
Generation of Quadrature Squeezed Vacuum Light Field for Cesium D1 Line
Zhang Yan, Liu Jinhong, Ma Rong, Wang Dan, Han Yuhong, and Zhang Junxiang
The non-classical light at alkali atomic absorption lines is one of the important resources for quantum information networks, and it gets more attentions recently. Because of the unique wavelength of the non-classical light field at cesium D1 line, it has important application prospect in the field of solid-state quantThe non-classical light at alkali atomic absorption lines is one of the important resources for quantum information networks, and it gets more attentions recently. Because of the unique wavelength of the non-classical light field at cesium D1 line, it has important application prospect in the field of solid-state quantum information networks. Continuous wave single frequency Ti: sapphire laser is used as light source. The 447.3 nm blue laser is generated by the output 894.6 nm laser locked at cesium D1 line via frequency doubling of external cavity. The blue laser is used to pump continue wavelength degeneration optical parametric oscillator, and the nonlinear medium of the oscillator is periodically poled KTP (PPKTP) crystal. Then the simple module quadrature squeezed vacuum light at cesium D1 line is obtained. The threshold of the optical parametric oscillator is 39 mW. When the pump power is 30 mW, quadrature squeezing degree measured by balanced homodyne detector is 2.8 dB. Taking account of detection efficiency, the actual squeezing degree of the output light field of optical parametric oscillator reaches 4.4 dB..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 519001 (2017)
Optical Short Pulse with Dual Wavelength and High Stability Based on Optoelectronic Oscillator and Soliton Compression
Chen Bin, Jia Shi, Wang Ju, Wang Wenrui, Wang Zixiong, and Yu Jinlong
One effective scheme to generate optical short pulses based on chirp compression and soliton compression effects in the dual-loop optoelectronic oscillator (OEO) with different wavelengths is proposed. Dual-wavelength optical short pulses can be generated simultaneously with the proposed scheme. By modulating the high-One effective scheme to generate optical short pulses based on chirp compression and soliton compression effects in the dual-loop optoelectronic oscillator (OEO) with different wavelengths is proposed. Dual-wavelength optical short pulses can be generated simultaneously with the proposed scheme. By modulating the high-quality microwave signal generated by the dual-loop OEO into the directly modulated lasers and the phase modulator, optical pulses and chirps can be obtained. The maximum chirp rate of the optical pulses is achieved by adjusting the optical delay between the directly modulated laser and the phase modulator. The chirp compression and soliton compression of optical pulses are conducted by utilizing the dispersion compensation fiber and the highly nonlinear fiber, respectively and the final optical pulse width is as narrow as 1.2 ps. After the system cavity length is effectively controlled with the phase-locked-loop technology, the long-term stability of optical pulses is further improved..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 519002 (2017)
Optical Design and Fabrication
Solar Concentrator Mirror Unit Supporting-Adjusting Structure and Posture Alignment
Yan Jian, Peng Youduo, Cheng Ziran, and Tan Xinhua
In order to achieve fast error alignment in concentrator mirror unit installation, a mirror unit supporting-adjusting structure consists of threaded vice and ball joint is designed to precisely control the adjusting amount. A fast measurement method of mirror unit posture (axis vector and vertex position) and a quantitIn order to achieve fast error alignment in concentrator mirror unit installation, a mirror unit supporting-adjusting structure consists of threaded vice and ball joint is designed to precisely control the adjusting amount. A fast measurement method of mirror unit posture (axis vector and vertex position) and a quantitative alignment method of axis vector posture error are proposed. Firstly, the photogrammetry method is applied to determine the three feature points (construct a triangle) coordinates in the mirror unit surface. Then, an association mathematical model of the ball joint center coordinates, the mirror unit posture, and the feature points coordinates is established to achieve fast measurement of the mirror unit posture. After that, combined with the mirror unit alignment process, we propose the “three rotational-one moving” rigid body motion (three rotate around axis and one moving) to equate the mirror posture error. The mirror unit posture associated with the bolt adjusting quantity model is established to achieve the quantitative alignment of mirror unit axis vector error. Finally, the convenience of the mirror unit supporting-adjusting structure and the effectiveness of the axis vector quantity alignment method are verified by the virtual alignment experiment established by SolidWorks software and metal flat surface posture alignment experiment in door. The proposed mirror unit alignment method is not restricted by the reflector geometry and it has extensive applicability..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 522001 (2017)
Design and Imaging Distortion Correction of Pin-Hole Objective Lens with Large Field
Hu Mingyong, Li Mingjie, Zhao Qi, Fan Errong, and Feng Zhiwei
An optical system of pin-hole objective lens with large field is designed with relative aperture of 1/5, focus length of 5 mm and field angle of 125°. In this structure, the modulation transfer function for all fields is bigger than 0.5 at 50 lp/mm, and the imaging reaches the diffraction limit, but the full fieldAn optical system of pin-hole objective lens with large field is designed with relative aperture of 1/5, focus length of 5 mm and field angle of 125°. In this structure, the modulation transfer function for all fields is bigger than 0.5 at 50 lp/mm, and the imaging reaches the diffraction limit, but the full field distortion rate reaches -46%. According to optical imaging theory and image processing technology, the lattice template is used to calculate the optical center and the distortion coefficient. The distortion correction model is built and distortion correction algorithm is designed. With a combination of linear imaging model and distortion correction model, the calibration equation of distortion correction rate is built. The distortion correction rate obtained by this algorithm is 96.17%. This calibration method is compared with other methods, and we find that the proposed method is simple and practicable. The proposed method basically meets the needs of industry, and it can be widely used in image distortion correction of large field lenses..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 522002 (2017)
Design of Aspheric Cylindrical Lens of Uniform Light Distribution for Circumferential Detection
Zheng Xiang, and Zhao Baiqin
A solution of partition detection based on aspheric cylindrical lens array is proposed, which aims at the requirements of circumferential detection system on the detection laser beam divergence angle and energy distribution. Source of the detection system is a fast-axis collimated laser diode array. Slow-axis light powA solution of partition detection based on aspheric cylindrical lens array is proposed, which aims at the requirements of circumferential detection system on the detection laser beam divergence angle and energy distribution. Source of the detection system is a fast-axis collimated laser diode array. Slow-axis light power is distributed via aspheric cylindrical lens array. Collimated line source approximation is put forward to simplify the complicated process of corresponding calculation on Gaussian beam, and an equation of the aspheric curve is finally established. The aspheric cylindrical lens array is determined by applying this equation, the system can obtain outgoing beam with adjustable divergence angle and uniform power density distribution about plane angle in sagittal plane. And the evenness can reach 98.64%. A lens array with wavy structure is designed to diminish the effect of tolerance of optical system. According to tolerance analysis, the refractive index tolerance of lens material only influences the beam divergence angle instead of the evenness of light distribution. And the traditional structure of lens array is replaced by wavy structure so that wedge shape between adjacent lens can be eliminated effectively, which reduces the difficulty and tolerance in manufacture. Moreover, the length of line source is consistent with the periods of lens array, which weakens the influences of tolerance of lens eccentricity and lens tilt during fabrication..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 522003 (2017)
Optical Devices
Design of X-Ray Framing Camera with Single Perspective
Zong Fangke, Zhang Jingjin, Lei Baoguo, Guo Baoping, and Yang Qinlao
In view of the inconsistent perspective in target images obtained by pinhole array for traditional X-ray gating micro channel plate (MCP) framing camera, an implement method of X-ray framing camera with single perspective is proposed. At the electro-optic intersection in electrostatic focus image tube, the electrons caIn view of the inconsistent perspective in target images obtained by pinhole array for traditional X-ray gating micro channel plate (MCP) framing camera, an implement method of X-ray framing camera with single perspective is proposed. At the electro-optic intersection in electrostatic focus image tube, the electrons carry holographic information, and can be divided into multiple output images with single perspective, subsequently a gated MCP unit is matched with the frame to enhance the target image. Compared with the traditional gated MCP framing camera, the designed framing camera realizes identity of image perspective and avoids direct light′s excitation on screen, and a higher signal-to-noise ratio is obtained. The designed framing image tube has an effective input working diameter of 40 mm, an output image diameter of 40 mm, a magnification of 1.29, the center spatial resolution of 60 lp/mm in theory, the marginal spatial resolution of 26 lp/mm, and the geometric distortion of less than 15%. Single frame exposure duration is determined by shutter pulse time of gated MCP framing unit. This method is an effective way to realize identity of image perspective for X-ray framing image camera..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 523001 (2017)
Flat-Field Measurement Method of Coronagraph with Opal Glass
Bai Xianyong, Wang Yiran, Zhang Zhiyong, Feng Zhiwei, Deng Yuanyong, Liu Siqing, Ji Kaifan, Guo Jingjing, and Zhang Yang
Flat-field correction can remove the non-uniformity in the coronagraph imaging process, which is a necessary step in its data calibration. The device and method for measuring flat-field of coronagraph based on an opal glass are proposed in this paper. Some simulations and site measurements are carried out to verify theFlat-field correction can remove the non-uniformity in the coronagraph imaging process, which is a necessary step in its data calibration. The device and method for measuring flat-field of coronagraph based on an opal glass are proposed in this paper. Some simulations and site measurements are carried out to verify the feasibility of this method. First of all, the uniformity of the diffused sunlight passing through the opal glass in the field of view of the coronagraph is simulated. The simulation result shows that its uniformity is 99.98%, which is very close to the ideal and uniform area source. Moreover, the flat-field of the 12 cm ground-based coronagraph is measured. The observational result indicates that the non-uniformity of the coronagraph imaging can be observed with this method, such as the fringes on the detector. The result after flat-field correction agrees well with the radial distribution of the background luminance of coronagraph and sky. Lastly, the flat-fields from the opal glass are compared with the sky flats in order to evaluate the validity of flat-field measurement with opal glass. Their correlation coefficient is 99.94% and the corresponding linear fitting slope is 1, which shows a strong correlation..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 523002 (2017)
Experimental Preparation of Bipartite Polarization Entangled Optical Fields at 795 nm
Wu Liang, Liu Yanhong, Deng Ruijie, Yan Zhihui, and Jia Xiaojun
Bipartite polarization entangled optical fields are theoretically analyzed and experimentally prepared. When the analysis frequency is 1.8-6.5 MHz, the normalized quantum correlation noise of Stokes operator is below 1, where the bipartite polarization entangled state is obtained. When the analysis frequency is above 3Bipartite polarization entangled optical fields are theoretically analyzed and experimentally prepared. When the analysis frequency is 1.8-6.5 MHz, the normalized quantum correlation noise of Stokes operator is below 1, where the bipartite polarization entangled state is obtained. When the analysis frequency is above 3 MHz, the correlation noise reaches 0.5. This non-classical light source can be applied in quantum memory in future and to realizing the entanglement and quantum state transfer between the quantum channel and quantum node or between two quantum nodes..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 523002 (2017)
Realization and Optimization of Holographic Waveguide Display System
Liu Ao, Zhang Yuning, Shen Zhongwen, and Wang Baoping
In the near-eye display system of holographic optical waveguide, the carrier wave emitted from the micro-image source is collimated and then coupled into the slab waveguide by input coupling grating. The wave propagates through the upper and lower surfaces of the slab waveguide with total reflection. After reaching theIn the near-eye display system of holographic optical waveguide, the carrier wave emitted from the micro-image source is collimated and then coupled into the slab waveguide by input coupling grating. The wave propagates through the upper and lower surfaces of the slab waveguide with total reflection. After reaching the output end, passing through output coupling grating, the wave propagates out of the waveguide and finally reaches the human eye. In order to achieve real image transmission, aspects such as the holographic diffraction efficiency and the field of view are theoretically analyzed and optimally designed. A holographic grating with grating period of 197 nm, grating vector angle of 26°, and thickness of 7.5 μm is fabricated in the laser interference exposure experiment. The peak efficiency of the grating is more than 80%. Combined with waveguide optical design, we realize the image transmission..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 523003 (2017)
Physical Optics
Study on High-Numerical-Aperture-Focused Characteristics by π Phase Diaphragm Modulation
Cai Xunming, Zhao Jingyun, Tong Hong, Luo Jiaolian, Yang Yingye, and Li Lingfu
The strong axial electric field component can be obtained in the focus area by an annular diaphragm with a larger radius. In contrast, by another annular diaphragm with a smaller radius which combines with a π phase plate, the axial electric field distribution can be obtained in the focus area with the vibration directThe strong axial electric field component can be obtained in the focus area by an annular diaphragm with a larger radius. In contrast, by another annular diaphragm with a smaller radius which combines with a π phase plate, the axial electric field distribution can be obtained in the focus area with the vibration direction opposite to that of the axial electric field produced by the annular diaphragm with a larger radius. Consequently, the focused spot formed by the annular diaphragm with a larger radius in the focus area is reshaped. In certain conditions, the size of the focused spot can be greatly reduced. The study results show that, compared with that when using sing annular diaphragm, the size reduction of the focused spot with the proposed method can be more than 40 nm..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 526001 (2017)
Characteristics of Far-Field Distributions of Gaussian Beams with Non-Paraxial LG00 Mode and LG10 Mode
Zhu Zhilü, Li Lianhuang, Guo Fuyuan, and Li Weixian
Based on the expressions of electric field distributions of non-paraxial Gaussian beams in the oblate ellipsoid coordinate system, an expression of far-field electric field amplitude distribution of the non-paraxial LG10 mode Gaussian beam is given. The characteristics of far-field electric field amplitude distributionBased on the expressions of electric field distributions of non-paraxial Gaussian beams in the oblate ellipsoid coordinate system, an expression of far-field electric field amplitude distribution of the non-paraxial LG10 mode Gaussian beam is given. The characteristics of far-field electric field amplitude distributions of the Gaussian beams with non-paraxial LG00 mode and non-paraxial LG10 mode are analyzed. The matching effciencies of the far-field electric field amplitude distributions and the relative calculation errors of the second-order moment parameters of the electric field intensity distributions of the non-paraxial and paraxial Gaussian beams are calculated. It is shown that the far-field electric field amplitude distributions of the non-paraxial LG00 mode and LG10 mode Gaussian beams tend to coincide with the far-field electric field amplitude distributions of the paraxial LG00 mode and LG10 mode Gaussian beams when the half of focal length of the oblate ellipsoid coordinate system is much larger than the wavelength..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 526002 (2017)
Quantum Optics
Round Robin Differential Phase Shift Quantum Key Distribution Protocol Based on Heralded Single Photon Source and Detector Decoy State
Hu Kang, Mao Qianping, and Zhao Shengmei
A novel round robin differential phase shift quantum key distribution protocol based on heralded single photon source and detector decoy state is proposed, which is named as HSPS-DD-RRDPS-QKD protocol. The key generation rate of the proposed protocol is derived in detail, and the relevant numerical simulation is presenA novel round robin differential phase shift quantum key distribution protocol based on heralded single photon source and detector decoy state is proposed, which is named as HSPS-DD-RRDPS-QKD protocol. The key generation rate of the proposed protocol is derived in detail, and the relevant numerical simulation is presented. The performance of the proposed protocol is compared with that of the round robin differential phase shift quantum key distribution based on weak coherent source and detector decoy state (named WCS-DD-RRDPS-QKD) protocol and that of the decoy state BB84 protocol, respectively. The results show that the key generation rate and the farthest transmission distance decrease with the increase of the pulse sequence length L. When the pulse sequence length L=16, the security communication distance of the HSPS-DD-RRDPS-QKD protocol increases by nearly 100 km and the key generation rate increases by one order of magnitude compared with those of the WCS-DD-RRDPS-QKD protocol. When the system error rate is 9.5%, the key generation rate of the HSPS-DD-RRDPS-QKD protocol is nearly two orders of magnitude higher than that of the decoy state BB84 protocol..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 527002 (2017)
Remote Sensing and Sensors
Nonuniformity Correction Method Based on Gradient Scenes
Zhou Dabiao, Wang Dejiang, Huo Lijun, Liu Rang, and Jia Ping
Long wave infrared detectors are often employed in airborne infrared early warning systems, which are often contaminated the with heavy nonuniformity noises. To correct the nonuniformity and compensate the nonlinearity of detectors, a nonuniformity correction method is proposed. The observation model of radiance nonuniLong wave infrared detectors are often employed in airborne infrared early warning systems, which are often contaminated the with heavy nonuniformity noises. To correct the nonuniformity and compensate the nonlinearity of detectors, a nonuniformity correction method is proposed. The observation model of radiance nonuniformity is introduced. The correction coefficients are deduced in theory with the reference of a blackbody and a gradient scene. And, an outfield experiment with a proof-of-concept camera is performed to detect the airliners. Experimental results show that the peak value of local standard deviation of the corrected image decreases from 8.57 to 2.39, compared with the two-point correction method based on a blackbody. For the target of Airbus A319 from 50.64 km away, the signal-to-clutter ratio rises from 4.87 to 11.22. The proposed method can decrease the local standard deviation effectively, which has a significant contribution to airborne infrared early warning systems..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 528001 (2017)
Accurate Spatial Co-Registration of Multi-Angle Multi-Source Remote Sensing Data Based on Self-Defined Projection Grids
Li Jian, Chen Shengbo, Wang Yufei, and Yu Yan
An accurate spatial co-registration method for multi-angle multi-source remote sensing data based on self-defined projection grids is proposed. Taking the accurate spatial co-registration between the multi-angle imaging spectroradiometer (MISR) L2 products and moderate-resolution imaging spectroradiometer (MODIS) L3 prAn accurate spatial co-registration method for multi-angle multi-source remote sensing data based on self-defined projection grids is proposed. Taking the accurate spatial co-registration between the multi-angle imaging spectroradiometer (MISR) L2 products and moderate-resolution imaging spectroradiometer (MODIS) L3 products carried on American earth observation satellite (EOS) as an example, the data processing abilities of ENVI, HEG, MRT softwares and the proposed method when the reprojection is performed on two kinds of products are compared and analyzed. In order to verify the proposed method, the advanced along track scanning radiometer (AATSR) data from the environmental satellite ENVISAT of European Space Agency are co-registered with the MISR and MODIS data. The proposed method solves the problem that MISR L2 product data cannot be directly and accurately registered with other remote sensing data by using common remote sensing data processing softwares, which only resamples once and can avoid the possible information loss caused by repeated resamples. The basic ideas and objectives of the proposed method are also applicable to the spatial accurate co-registration of other similar multi-angle remote sensing data..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 528002 (2017)
Reviews
Cladding-Modulation Bragg Grating with Asymmetric Structure
Liu Chunjuan, Yang Chaoshan, Lian Le, Xu Xiaorui, and Hu Yanwei
In order to optimize the performance of gratings,one cladding-modulation grating with an asymmetric structure is proposed based on the complementary metal oxide semiconductor compatibility fabrication technique. By adjusting the position of grating teeth, the coupling efficiency of the transmission light in the waveguiIn order to optimize the performance of gratings,one cladding-modulation grating with an asymmetric structure is proposed based on the complementary metal oxide semiconductor compatibility fabrication technique. By adjusting the position of grating teeth, the coupling efficiency of the transmission light in the waveguide is altered, which eventually achieves the improvements of reflection bandwidth, extinction ratio and output power of the grating. The effect of the improved grating structure on coupling coefficient, reflection bandwidth and output performance of gratings is analyzed by using the coupled mode theory, and the numerical simulation is conducted as well with the finite element method. The results show that the reflection bandwidth of the improved grating is reduced from 0.9 nm to 0.3 nm, the absolute value of the extinction ratio is increased from 29.2 dB to 35.1 dB, and the optical power dissipating in the claddings is decreased from 5.99×10-5 W to 3.13×10-5 W. The performance of the improved grating device is improved..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 505002 (2017)
Scattering
Effect of Relative Humidity of Atmospheric Aerosol on Radiation Properties of Soot Aggregate
Yin Jinying, Zheng Yunong, Yang Hongyan, and Zhou Zhen
According to the fractal theory, soot aggregates which have typical morphologies coated with water are generated in high and low relative humidity conditions. The relationships among relative humidity of atmospheric aerosol, equivalent refractive index and radius of soot particle are investigated. It is found that the According to the fractal theory, soot aggregates which have typical morphologies coated with water are generated in high and low relative humidity conditions. The relationships among relative humidity of atmospheric aerosol, equivalent refractive index and radius of soot particle are investigated. It is found that the radius of soot particle coated with water remarkably increases with the increase of relative humidity. The radiation properties of soot particles are calculated by means of Maxwell-Garnett (MG) theory and T matrix (MG-T) method, while the accuracy of the calculation results is verified by Coat-Mie theory. The calculation results of the radiation properties of soot particles calculated by MG-T method are in well agreement with that by Coat-Mie theory. The radiation properties of two kinds of soot aggregates in infrared wavelength are calculated by MG-T method. The results reveal that the values of radiation properties of packed soot aggregates are much larger than those of the branched soot aggregates with the increasing relative humidity. When the relative humidity is larger than 50%, the values of the radiation properties of the two kinds of soot aggregates increase due to the increase of water layer thickness and radius of soot aggregates. It is confirmed that the radius of soot aggregates plays a critical role in determining the radiation properties for soot aggregates..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 529001 (2017)
Thin Films
Design and Preparation of Multilayer Dielectric Beam Splitter for Division-of-Amplitude Photopolarimeter at 1064 nm
Yuan Wenjia, Shen Weidong, Zhang Yueguang, Zheng Xiaowen, Mu Wen, Fang Bo, Yang Chenying, and Liu Xu
A differential phase shift beam splitter with a multi-layer dielectric film structure which is used for a division-of-amplitude photopolarimeter (DOAP) with an operating wavelength of 1064 nm is designed and prepared. The optimal parameters of beam splitter are obtained by analyzing instrument matrix parameters of the A differential phase shift beam splitter with a multi-layer dielectric film structure which is used for a division-of-amplitude photopolarimeter (DOAP) with an operating wavelength of 1064 nm is designed and prepared. The optimal parameters of beam splitter are obtained by analyzing instrument matrix parameters of the DOAP system. The beam splitter sample and its anti-reflection coating on the backside are prepared with the ion beam sputtering (IBS) deposition method. The experimental results are well consistent with the designed value. Comparing with single-layer film beam splitters, this multilayer dielectric film beam splitters possess a wider application, which is not limited by the substrate, layer materials, incident angle, and operating wavelength..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 37, Issue 5, 531001 (2017)
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