Contents
2011
Volume: 31 Issue 1
50 Article(s)
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Atmospheric Optics and Oceanic Optics
Abilitiy Analysis of Spatial Heterodyne Spectrometer in Atmospheric CO2 Detection
Wu Jun, Wang Xianhua, Fang Yonghua, Xiong Wei, Shi Hailiang, and Qiao Yanli
The necessity of using high-resolution near infrared spectra in space-based atmospheric CO2 detection is discussed. According to simulation results, some key parameters such as detection band, spectral resolution and singnal to noise ratio (SNR) for space-based CO2 detection are analysed. Based on these simulated paramThe necessity of using high-resolution near infrared spectra in space-based atmospheric CO2 detection is discussed. According to simulation results, some key parameters such as detection band, spectral resolution and singnal to noise ratio (SNR) for space-based CO2 detection are analysed. Based on these simulated parameters, a spatial heterodyne spectroscopy (SHS) prototype instrument is introduced. Then this prototype instrument′s spectral resolution and abilities in CO2 detection are verified by laboratory and out-door experiments. Using LBLRTM software and near-real-time atmospheric parameters acquired from National Centers for Environmental Prediction (NCEP), the ground-based observation data of the instrument is simulated. The comparison between simulation results and SHS prototype instrument′s measurements shows a good fit. It is proved that the SHS prototype instrument is very sensitive to atmospheric CO2 absorption, and the instrument′s measurements could be used for space-based atmospheric CO2 detection..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 101001 (2011)
Effect of Near-Field Light Intensity on Reconstructed Effect by Linear Phase Retrieval Algorithm
Wu Yunyun, Li Min, and Li Xinyang
The effect of the near-field intensity distribution on linear phase retrieval is analyzed in detail. Reconstructed results in cases of three distributions-tilt, ring, random-type near-field intensity distribution are compared with uniform intensity respectively. The results show that the reconstructed effect of tilt-tyThe effect of the near-field intensity distribution on linear phase retrieval is analyzed in detail. Reconstructed results in cases of three distributions-tilt, ring, random-type near-field intensity distribution are compared with uniform intensity respectively. The results show that the reconstructed effect of tilt-type which is composed of odd functions is adverse; while the reconstructed effect of ring and random-type which is composed of even functions is not large. Especially when the spatial frequency was higher, the reconstructed effects are smaller. In addition, near-field intensity and phase obtained from atmospheric turbulence distortion are simulated by using the linear phase retrieval algorithm. Near-field intensity distribution of the results have influence on the reconstruction, but the influence is not too great..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 101002 (2011)
Numerical Simulation of a Prediction Control Algorithm for Close-Loop Adaptive Optical System
Yan Zhaojun, Li Xinyang, and Rao Changhui
To reduce the servo lag error in adaptive optics system which corrects the atmosphere turbulence distortion, a prediction control algorithm to predict the control voltage of deformable mirror is proposed. The prediction control method with recursive least-square (RLS) algorithm is used to predict the voltage of deformaTo reduce the servo lag error in adaptive optics system which corrects the atmosphere turbulence distortion, a prediction control algorithm to predict the control voltage of deformable mirror is proposed. The prediction control method with recursive least-square (RLS) algorithm is used to predict the voltage of deformable mirror in advance. Numerical simulation, based on the atmospheric turbulence distorted wave-front slope data changing with different transversal wind is studied. The residual error of the adaptive optics system is calculated and compared with the prediction control algorithm and proportional integral (PI) control algorithm. The results show that the residual error caused by servo lag in the system is reduced more effectively by using the prediction control algorithm than by using the PI control algorithm..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 101003 (2011)
Attenuation and Transmission of Laser Radiation at 532 nm and 1064 nm through Rain
Guo Jing, Zhang He, and Wang Xiaofeng
Rainfall can bring serious attenuation to the laser signals, so it will take some influence to the laser detection system applied in the rain. The attenuation of laser beam propagating in the rain is lucubrated in the infrared range, but the attenuation of green laser in the rain has not been reported. Therefore, basedRainfall can bring serious attenuation to the laser signals, so it will take some influence to the laser detection system applied in the rain. The attenuation of laser beam propagating in the rain is lucubrated in the infrared range, but the attenuation of green laser in the rain has not been reported. Therefore, based on Fraunhofer diffraction and geometric optics theory, the attenuation model of laser radiation at 532 nm and 1064 nm by raindrops is founded, and the attenuation characteristics are contrasted and analyzed. Then, the veracity of attenuation model is validated by experiments. Theory analysis and experimental results indicate that the differences of the scattering loss between the two wavelengths are slight, but the absorption of the raindrops to the 1064 nm is obvious, so the transmittance of laser radiation at 1064 nm is lower than 532 nm. Attenuation and transmission characteristics of laser in rain provide theoretical basis for green laser applied in the detection system working in the rain..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 101004 (2011)
Atomic and Molecular Physics
Influence of Off-Resonant Coupling Field on Electromagnetically Induced Transparency and Electromagnetically Induced Absorption in A Closed Λ-Shaped Four-Level System
Li Xiaoli, Liu Hongna, and Yang Yue
Electromagnetically induced transparency (EIT) and electromagnetically induced absorption (EIA) are intriguing nonlinear phenomena of light-atom interaction. The study on their nonlinear behaviors has theoretical significance and potential applications. A closed-lambda four-level system consisting of hyperfine levels oElectromagnetically induced transparency (EIT) and electromagnetically induced absorption (EIA) are intriguing nonlinear phenomena of light-atom interaction. The study on their nonlinear behaviors has theoretical significance and potential applications. A closed-lambda four-level system consisting of hyperfine levels of excited state and those of ground state is proposed. In addition to a coupling field and a probing field, there are two radio-frequency fields which interact with hyperfine levels of excited state and those of ground state, respectively. In order to focus on detuning effect of the coupling field on the system, two resonant radio-frequency fields are used. By solving the equations of density matrix motion, both EIT and EIA are obtained in the system, and the frequency and feature of EIT or EIA are controlled by tuning the detuning of coupling field..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 102001 (2011)
Generation of Raman laser for STIRAP of Cs Atom
Li Zhuoheng, Li Gang, Zhang Yuchi, Zhang Pengfei, Zhao Dongmei, Guo Yanqiang, Wang Junmin, and Zhang Tiancai
The stimulated Raman adiabatic passage (STIRAP) is an important technique in controlling the atomic states and it has been widely used in atom manipulation and quantum information. Obtaining Raman laser is the first step to demonstrate the STIRAP for atoms. A system is presented for generating Raman laser for STIRAP prThe stimulated Raman adiabatic passage (STIRAP) is an important technique in controlling the atomic states and it has been widely used in atom manipulation and quantum information. Obtaining Raman laser is the first step to demonstrate the STIRAP for atoms. A system is presented for generating Raman laser for STIRAP process for Cs atom based on waveguide fiber modulation with high frequency and two pieces of interference filter. Two sidebands with frequency difference of exact 9.19 GHz are separated from the carrier and each of them can be controlled independently. The distinction ratio between the sidebands and the carrier is 21 dB. The power of each sideband is about 120 μW and the fluctuation is less than 2% in ten minutes. This system could be used in atomic state preparation and coherent control of the atomic states..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 102002 (2011)
Fiber Optics and Optical Communications
Transmission Efficiency of Bending Fiber with Small Radius
Yao Shun, Pang Xiaolin, Dai Jingjing, Liu Xuesheng, Cao Yinhua, and Wang Zhiyong
Based on the analysis of propagation ray theory in cladding layer of multimode power delivery optical fiber and the high-power diode laser pigtail fiber bending experiment, part of the light transports into the cladding layer because fiber bending is found transporting back to the fiber core, especially when the lengthBased on the analysis of propagation ray theory in cladding layer of multimode power delivery optical fiber and the high-power diode laser pigtail fiber bending experiment, part of the light transports into the cladding layer because fiber bending is found transporting back to the fiber core, especially when the length of the bending fiber is short. It means that transmission efficiency of bending fiber is determined by bending radius and bending length. A high transmission efficiency of power in fiber at small bending radius can be obtained when the length of bending is well chosen..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 106001 (2011)
Characteristic Analysis of LPFG Resonance Wavelength Shift Owing to Transverse Load
Zeng Xiangkai, Rao Yunjiang, and Liang Kuai
The sensing characteristics of long-period fiber grating (LPFG) resonance wavelength shift owing to transverse load are theoretically analyzed, by considering influential factors such as strain-optic effect and the change of wave guide structure. The characteristics include the resonant wavelength shift and the intervaThe sensing characteristics of long-period fiber grating (LPFG) resonance wavelength shift owing to transverse load are theoretically analyzed, by considering influential factors such as strain-optic effect and the change of wave guide structure. The characteristics include the resonant wavelength shift and the interval between two resonant sub-peaks (namely transmission sub-pits) split in LPFG spectrum. According to the analytical properties, the sensitivity coefficients of the resonant wavelength shifts and the sub-peak wavelength interval, which are due to transverse load for a long-period fiber grating in single-mode fiber, are numerically calculated. The simulation results show that the shift directions and sensitivity coefficients of resonant wavelengths are dependent on the polarizations of light source. The resonant wavelength of linear polarization source in the direction of forcing transverse load shifts to shorter wavelength (blue shift), and the resonant wavelength corresponding to the polarization in the orthogonal direction of forcing shifts to longer wavelength (red-shift). The shift ratio of resonant wavelength to longer wavelength is over 2 times larger than that to shorter wavelength. The birefringence caused by transverse load splits the resonant peak (transmission pit) into two resonant sub-peaks in LPFG spectrum. The sub-peak shifts and the interval between two resonant sub-peaks are well linear with the transverse load, which can be used for highly sensitive measurement or absolute measurement of transverse load. These conclusions are in good agreement with the published results of the transverse load experiments..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 106002 (2011)
Theroretical Study on a Kind of Photonic Crystal Fiber Grating Based on Structural Change
Qi Yuefeng, and Bi Weihong
A kind of novel photonic crystal fiber grating based on structural change is researched. The influence of refractive index brought by structural change is studied by using multipole method. The relation between effective refractive index and collapsed cladding pillars is gotten. The model of structural changed photonicA kind of novel photonic crystal fiber grating based on structural change is researched. The influence of refractive index brought by structural change is studied by using multipole method. The relation between effective refractive index and collapsed cladding pillars is gotten. The model of structural changed photonic crystal fiber grating is built. Furthermore, the influence of cladding layers of pillars and the degree of collapsed pillars are discussed. It is shown that periodic collapsed pillars can form grating, and that not only the extent of collapsed pillars, but also the collapse envelope has influence on the magnitude and distribution of effective refractive index. As the layers of pillars increase, the resonant wavelength shows blue shift, the grating has wider bandwidth and weaker resonance intensity. Under the same fiber structure, resonant wavelength shows red shift and grating has narrower bandwidth with increasing the extent of collapsed pillars..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 106003 (2011)
Quantum Limits of Far-Field Beam Pointing Accuracy in Space
Wu Jili, Zhao Shanghong, Li Yongjun, Chu Xingchun, Li Qin, Zhu Zihang, and Shi Lei
Based on the equality of Helmholtz equation and stationary state Schrdinger equation, focalizing plane wave is just the transformation of state function of a photonic from coordinate representation to momentum representation. However, as a result of limited aperture size, the state function in the momentum space couldBased on the equality of Helmholtz equation and stationary state Schrdinger equation, focalizing plane wave is just the transformation of state function of a photonic from coordinate representation to momentum representation. However, as a result of limited aperture size, the state function in the momentum space could not be reconstructed exactly, which leads to the quantum precision limits of alignment. Under the conditions of quantum limits, the precision is approximately 26% of the diffraction limited angle. It depends on the aperture size only and is irrespective to the focal length. The centroid method on the focal plane could only reach the precision close to the diffraction limited angle. The root mean square of remained errors is still 3.24 times of the quantum limits..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 106004 (2011)
Study of Band-Pass Filtering Characteristics of W-Type Dispersive Fibers
Song Peng, Ji Minning, and Yu Yan
Band-pass filtering characteristics of W-type dispersive fiber are studied by combining online filtering dispersive optical fiber with W-type fiber which is long wavelength cutoff. A band-pass filter can be achieved by appropriate structure composed of SiO2 core, SiO2-F inner cladding and SiO2-B2O3 outer cladding respeBand-pass filtering characteristics of W-type dispersive fiber are studied by combining online filtering dispersive optical fiber with W-type fiber which is long wavelength cutoff. A band-pass filter can be achieved by appropriate structure composed of SiO2 core, SiO2-F inner cladding and SiO2-B2O3 outer cladding respectively. According to finite element method simulation and numerical calculation, energy loss of fundamental mode and energy distributions at some wavelength of the stopped band or passband can be obtained, and the cutoff wavelength and bandwidth can be adjusted by controlling the dopant concentration and structure parameters. The influence of the core radius and the central air hole on the filtering performance is analyzed. The results show that decreasing the core radius or enlarging the air hole will reduce bandwidth and increase the passing band edge steepness..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 106005 (2011)
Coupled-Mode Characteristics of Coupled-Microdisks and Single Microdisk Cavity with an Output Waveguide
Wang Jiaxian, Li Junjie, Wu Wenguang, and Huang Yongzhen
The optical microresonators with high Q factor and ultra-small mode volume have attracted great attentions for applications in optoelectronic devices. For a coupled-microdisks and a single microdisk connected with an output waveguide, coupled mode characteristics resulting from the structure asymmetry are investigated The optical microresonators with high Q factor and ultra-small mode volume have attracted great attentions for applications in optoelectronic devices. For a coupled-microdisks and a single microdisk connected with an output waveguide, coupled mode characteristics resulting from the structure asymmetry are investigated by the finite-difference time-domain (FDTD) method and the Padé approximation. Mode field patterns and mode Q factors are calculated, and the relative energies of mode-field components with different angular wave numbers are estimated from the coupled mode-field distribution. For coupled microdisk resonator, the higher-order modes introduced by the mode coupling usually reduces the mode Q factor of the coupled mode greatly. For a single microdisk resonator with a radius of 1 μm and a refractive index of 3.2 connected with a 0.2-μm-wide output waveguide, a coupled mode at the wavelength of 1.52 μm is observed with the mode Q factor of 268 and a triangle mode-field pattern, which is the coupled mode between whispering-gallery modes TE9,1 and TE6,2 with a wavelength difference of 6.6 nm..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 106006 (2011)
Mathematical Model of Optical Wedges for Cross-Correlation Demodulation of Cavity Length of Optical Fiber Fabry-Pérot Sensors
Zhao Yan, and Wang Daihua
The optical wedge plays a vital role in the cross-correlation demodulation system of optical fiber Fabry-Pérot(F-P) sensors. A mathematical model for the light intensity reflected from the optical wedge is established based on analyzing results of the factors that cause the interference optical phase differences bThe optical wedge plays a vital role in the cross-correlation demodulation system of optical fiber Fabry-Pérot(F-P) sensors. A mathematical model for the light intensity reflected from the optical wedge is established based on analyzing results of the factors that cause the interference optical phase differences between the optical wedge and the F-P cavity of optical fiber F-P sensors according to the cross-correlation demodulation principle. The light intensity reflected from the optical wedges with different reflectivity combinations are numerically simulated and a simplified mathematical model for the light intensity reflected from the optical wedge is established by comparing the light intensity reflected from the optical wedge with those from the F-P cavity with the same reflectivity combinations. The analysis results of errors between the simplified mathematical model and the mathematical model indicate that the error of the simplified mathematical model for optical wedges is less than 0.6% when the optical wedge angle is less than 0.1° and the product of two surfaces′ reflectivity is not more than 9%. The simplified theoretical model of the optical wedges lays a theoretical foundation for establishing optical fiber F-P sensor systems based on the cross-correlation demodulation principle and further improving the accuracy of the demodulation system..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 106007 (2011)
Fourier Optics and Signal Processing
Spectrum Properties of Gaussian-Shell Mode Beam in the Chromatics Aberrated Fractional Fourier Transforms System
Chen Senhui, Zhang Tingrong, Huang Yongchao, Song Hongyuan, Zhang Weilin, and Li Yantao
Based on the Collins integral formula, the analytical spectral equations of the propagation of Gaussian-Shell mode (GSM) beam through a chromatics aberrated fractional Fourier transform (FRFT) system are derived. By giving the example of Lohmann II system, the effect of chromatic aberration coefficient, FRFT order and Based on the Collins integral formula, the analytical spectral equations of the propagation of Gaussian-Shell mode (GSM) beam through a chromatics aberrated fractional Fourier transform (FRFT) system are derived. By giving the example of Lohmann II system, the effect of chromatic aberration coefficient, FRFT order and the relative transverse coordinate on the normalized intensity distributions and relative spectral shift on exporting surface are analyzed numerically. It is shown that the relative spectral shift changes with the FRFT order. The value of chromatic aberration can affect the value of the relative spectrum shifting, the critical FRFT order, at which the spectral switch taking place, and the magnitude of the spectral jumping. The relative spectrum shift changes with FRFT, and there are differences of changing rules of that in systems with different FRFT order. In addition the normalized specteum and relative spectral shift change with the chromatic aberration coefficient and relative transverse coordinate as well..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 107001 (2011)
Properties of the Fractional Dual Nonlinear Correlator
Yang Xiujuan, Zhang Xiaoqiu, Yang Ming, Liu Zhengjun, and Liu Shutian
The fractional Foruier transform (FrFT) is introduced into the dual nonlinear optical correlation. The dual nonlinear fractional correlation can be realized by the nonlinear operations on the FrFT of the reference images and the target ones. The proposed scheme gives different weights to different shapes and textures bThe fractional Foruier transform (FrFT) is introduced into the dual nonlinear optical correlation. The dual nonlinear fractional correlation can be realized by the nonlinear operations on the FrFT of the reference images and the target ones. The proposed scheme gives different weights to different shapes and textures by nonlinear parameters and fractional orders. Therefore the properties of target recognition can be controlled. The dual nonlinear fractional correlator can be implemented by an opto-electronical setup. The simulation results show that the most remarkable characteristic of this system is that it has the variable and adjustable discrimination capability to shape changes and texture distortions of the objects. In addition it can improve the performances of the correlation output peak and it has better rubustness to noise..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 107002 (2011)
Instrumentation, Measurement and Metrology
Local Birefringence of Anisotropic Film Measured by Leaky Radiation-Mode Microscope
Yan Jie, Lu Yonghua, Wang Pei, and Ming Hai
There are several methods for birefringence measurement such as ellipsometer and optical coherence tomography. A novel method for birefringence measurement is proposed. The waveguide-mode resonance is excited by leaky radiation-mode microscope with azimuthally polarized beam illumination. By observe the Fourier spectruThere are several methods for birefringence measurement such as ellipsometer and optical coherence tomography. A novel method for birefringence measurement is proposed. The waveguide-mode resonance is excited by leaky radiation-mode microscope with azimuthally polarized beam illumination. By observe the Fourier spectrum on back focal plane, the birefringence character can be measured. The principle of birefringence measurement with this method is analyzed and the photo-induced birefringence about Δn≈0.005 of azobenzene (AZO) polymer film is measured, which can achieve high sensitivity and high spatial resolution birefringence measurement..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 112001 (2011)
Error Analysis of Attitude Angle Measuring System Based on Photoelectric Collimation and Virtual Extension Imaging
Jiang Jie, Wang Haoyu, and Zhang Guangjun
An attitude angle measuring system based on photoelectric collimation and virtual extension imaging is established to enlarge field of view (FOV) of system. The FOV is virtually enlarged through multi-imaging. The main principles of system is introduced, and error sources which may affect measuring precision of system An attitude angle measuring system based on photoelectric collimation and virtual extension imaging is established to enlarge field of view (FOV) of system. The FOV is virtually enlarged through multi-imaging. The main principles of system is introduced, and error sources which may affect measuring precision of system are analyzed based on system model. Experiments on error sources and system measuring precision is simulated under their mathematic relations. Simulation result is used to analyze and verify the system design. The results show that the proposed factors indeed affect system measuring precision. Based on the results, approaches to reduce system error and improve precision can be proposed..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 112002 (2011)
Investigation of Measurement Uncertainty of Aspheric Surface Based on Null-Computer-Generated HolographyWang Xiaopeng1,2Gao Zhishan1Ma Jun1Shen Hua1Ma Yun1
Wang Xiaopeng, Gao Zhishan, Ma Jun, Shen Hua, and Ma Yun
Aspheric surface acts as an important role in optical system. Because of its high precision, large data information and easy alignment, interferometric measurement method based on null computer-generated hologram (CGH) element is widely emphasized in the field of optical metrology and optical manufacture. A paraboloid Aspheric surface acts as an important role in optical system. Because of its high precision, large data information and easy alignment, interferometric measurement method based on null computer-generated hologram (CGH) element is widely emphasized in the field of optical metrology and optical manufacture. A paraboloid acting as a special aspheric surface sample is measured in auto-collimated interferometric path by using flats and transmission spheres. Then error data are obtained by means of measuring the same sample with null-CGH in interferometric path. By the calculation of major error data, a conclusion that the measurement uncertainty can reach λ/10（λ=0.6328 μm）which meets the requirement of optical metrology if null-CGH is made in a flat of fused silica with enough thickness..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 112003 (2011)
Analysis of a Sub-Aperture Scanning Machine with Double-Rotating Arms for Large-Aperture Optical System Transmittance Measurements
He Yingwei, Li Ping, Feng Guojin, Wang Yu, Liu Zilong, Zheng Chundi, Wu Houping, Li Cheng, and Sha Dingguo
For the purpose of large-aperture optical system spectral transmittance measurements, a novel double-rotating scanning machine with double-rotating arms (SSMDA) is designed. The sub-aperture scanning beam spot obtained from the SSMDA can cover full aperture of large optical system. By considering the structural parametFor the purpose of large-aperture optical system spectral transmittance measurements, a novel double-rotating scanning machine with double-rotating arms (SSMDA) is designed. The sub-aperture scanning beam spot obtained from the SSMDA can cover full aperture of large optical system. By considering the structural parameters errors, mathematical models of the SSMDA based on homogeneous coordinate transformation matrixes are developed. A detailed methodology for analyzing the scanning errors Δηr is proposed and implemented in practical design process. The computational results of scanning errors Δηr carried out on the mathematical models are between -0.007 nm and 0.028 mm while scanning radius ηr≤400.000 mm. The proposed methodology, developed mathematical models and obtained computational results can be not only the design reference for similar machines but also the theoretical and data basis for large-aperture optical system spectral transmittance measurements based on double-rotating sub-aperture scanning method..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 112004 (2011)
Algorithm for Reconstructing the Whole-Aperture Wavefront from Annular Subaperture Hartmann-Shack Gradient Data
Xu Hongyan, Xian Hao, and Zhang Yudong
A new algorithm is proposed for annular subaperture stitching technology based on Hartmann-Shack wavefront sensor. The algorithm can reconstruct the whole-aperture wavefront without reconstructing annular subaperture wavefront. The algorithm is feasible for the limited Hartmann sampling frequency in annular subapertureA new algorithm is proposed for annular subaperture stitching technology based on Hartmann-Shack wavefront sensor. The algorithm can reconstruct the whole-aperture wavefront without reconstructing annular subaperture wavefront. The algorithm is feasible for the limited Hartmann sampling frequency in annular subaperture. By evaluating the sensitivity of the algorithm to the measurement noise of wavefront gradient data, the algorithm is not sensitive to the measurement noise of the wavefront gradient. The algorithm can stitch different abberations except spherical abberations with high precision. There is some defocus aberration in the residual aberration for reconstructing the spherical aberration, the root mean square value (RMS) of residual aberration depends on the RMS of the spherical aberration and it is decreased by removing the coupling error of the spherical aberration..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 112005 (2011)
Development and Application of a System for Fusion Reaction History Measurement
Peng Xiaoshi, Wang Feng, Tang Daorun, Liu Shenye, Jiang Xiaohua, and Liu Yonggang
In order to accurately measure the fusion reaction-rate of inertial confinement fusion experiments, a system has been developed for fusion reaction history measurement with high temporal resolution which is better than 40 ps. The system is composed of plastic scintillator and nose cone, an optical system and streak camIn order to accurately measure the fusion reaction-rate of inertial confinement fusion experiments, a system has been developed for fusion reaction history measurement with high temporal resolution which is better than 40 ps. The system is composed of plastic scintillator and nose cone, an optical system and streak camera. The thin piece of scintillator material acts as a neutron-to-light converter. The optical system images light from the scintillator surface to camera for recording.The camera simultaneously records an optical fiducial pulse which allows the camera time base to be calibrated relative to the incident laser. This system has been applied on the SG-Ⅲ prototype. Fusion reaction history and fusion reaction bang time have been measured for deuterium-tritium filled targets with netrons yields about 1010. Fusion reaction bang time can be measured with accuracy as low as 15 ps..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 112006 (2011)
Thermal Deformation Analysis of Optical Surfaces Caused by Environmental Temperature during Interferometric Testing
Chen Hua, Shi Zhenguang, Sui Yongxin, and Yang Huaijiang
For interferometric testing of optics with surface qualities of approximately 1 nm, thermally caused deformation of mirror surface cannot be ignored. The various temperature conditions of interferometer environment are analyzed and temperature distribution of the mirror under test is simulated using I-Deas software. ThFor interferometric testing of optics with surface qualities of approximately 1 nm, thermally caused deformation of mirror surface cannot be ignored. The various temperature conditions of interferometer environment are analyzed and temperature distribution of the mirror under test is simulated using I-Deas software. The temperature distribution was then used as thermal load of linear static analysis to perform mirror thermal deformation analysis. The peak-valley value and root-mean-square value surface figure error of a 300 mm convex lens caused by ambient temperature fluctuation is achieved. The environmental temperature fluctuation should be less than ±0.1 ℃, temperature difference be less than ±0.05 ℃ in mirror axis direction and ±0.1 ℃ in mirror diameter direction to perform optical test of 1 nm surface figure error, which is instructive to high quality optical testing..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 112007 (2011)
Digitized Foucault Tester for Quantitative Evaluation the Surface of Aspheric Optical Elements
Wang Xiaopeng, Zhu Rihong, Wang Lei, and Xu Rongguo
A digital knife-edge testing system is established. The knife-edge testing system is used to quantificatively evaluate the wavefront of conicoid aspherical optical element. Root mean square (RMS) and peak-to-valley (PV) values of wavefront aberration of aspherical optical element are given. Measurement results of digitA digital knife-edge testing system is established. The knife-edge testing system is used to quantificatively evaluate the wavefront of conicoid aspherical optical element. Root mean square (RMS) and peak-to-valley (PV) values of wavefront aberration of aspherical optical element are given. Measurement results of digital knife-edge testing system are compared with the measurement of interferometer. The measurement results show the consistency within 0.001 μm, which proves the feasibility of digital knife-edge testing system and the accuracy of the digital knife-edge testing system reported here. The measurement results are discussed in the end..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 112008 (2011)
Effect of Wave Plate on Nonlinear Error in Single-Frequency Polarized Laser Interferometer
Li Liyan, Yuan Yonggui, Wu Bing, Liu Binbin, Yang Jun, and Yuan Libo
The effect of wave plate on nonlinearity of single-frequency polarized laser interferometer in nano measurement is researched. An error analysis model of multi-wave-plate is established based on Jones matrices theory. The nonlinear error in interferometer induced by λ/2 and λ/4 wave plates is analyzed and nonlinear errThe effect of wave plate on nonlinearity of single-frequency polarized laser interferometer in nano measurement is researched. An error analysis model of multi-wave-plate is established based on Jones matrices theory. The nonlinear error in interferometer induced by λ/2 and λ/4 wave plates is analyzed and nonlinear error caused by the position of wave plate is experimentally studied. The results indicate that the adjustment accuracy of wave plate position has a great influence on measurement. In the range from 0 to 5°, the non-linearities caused by λ/2 and λ/4 wave plates are 6.5 nm and 9.5 nm respectively. The research results provide a beneficial reference for optical path adjusting and nonlinear errors compensation of orthogonal polarized laser interferometer..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 112009 (2011)
Dynamic Response Control and Analysis of Large Aperture Tiled Grating Mount
Zhang Junwei, Wang Xiao, Lin Donghui, Zhou Hai, Chen Liangming, Zhang Xiaomin, and Jing Feng
Tiled grating is an important approach to solve the problem of grating aperture limit, however, which will meet the problem of structral stability of tiled grating. According to the requirement of operation, the tiled grating mount was used, but the stability of tiled grating mount cannot satisfy the requirement fully.Tiled grating is an important approach to solve the problem of grating aperture limit, however, which will meet the problem of structral stability of tiled grating. According to the requirement of operation, the tiled grating mount was used, but the stability of tiled grating mount cannot satisfy the requirement fully. In order to determine the main factors which affect the stability of the grating mount, a muti-channel vibration test equipment is used to measure the ambient vibration around grating. The test indicates that vibration of heating, ventilation and air conditioning (HVAC) are the main factors that affect the stability of grating mount. The power spectral density of test (PSD) is used to optimize the dynamic response of the grating mount and the results indicate that increase of structure damp ratio can decrease the dynamic response of grating mount. According to the finite element analysis, the joint damp of grating amount′s combination planes is increased by applying high damp material. The experiment indicates that increase of structure damp ratio not only reduces the dynamic response greatly but also prolongs the stability time..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 112010 (2011)
Design and Study of an Optical System for a Far Ultraviolet Imaging Spectrograph in 120～180 nm Carried by Satellite
Yu Lei, Qu Yi, Lin Guanyu, and Wang Shurong
An optical system applied to the detection of 120～180 nm far ultraviolet waveband is developed for the study of ionosphere imaging spectrometer carried by satellite in China. The programme that uses off-axis parabolic as objective lens and Czerny-Turner system as imaging spectrum system structure is proposed after compAn optical system applied to the detection of 120～180 nm far ultraviolet waveband is developed for the study of ionosphere imaging spectrometer carried by satellite in China. The programme that uses off-axis parabolic as objective lens and Czerny-Turner system as imaging spectrum system structure is proposed after comparing different foreign programmes. The aberration theory is studied and a novel method of aberration correction is deduced to overcome the disadvantages of Czerny-Turner structure such as non-homogeneous aberration correction and low spatial resolution. Spectrograph system operating in 120～180 nm waveband with 4°field of view and 139.3 mm focal length is designed. The results demonstrate that the aberration of the system is substantially corrected and the modulation transfer function (MTF) of total field of view is more than 0.6 in all waveband, which satisfies the requirement. Compared with foreign loads, the structure is more convenient and predominant..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 112011 (2011)
Research of Errors Analysis and Material Removal Stability in Fluid Jet Polishing
Shi Chunyan, Yuan Jiahu, Wu Fan, and Wan Yongjian
Experiments is designed to research the instability of fluid jet polishing system. The results show that the material removal shape is dissymmetrical, and the material removal ratio is fluctuating with different polishing regions even on the same polishing condition. Then the influence factors of the instability is anaExperiments is designed to research the instability of fluid jet polishing system. The results show that the material removal shape is dissymmetrical, and the material removal ratio is fluctuating with different polishing regions even on the same polishing condition. Then the influence factors of the instability is analyzed, such as pressure fluctuation, abrasive particles deposition, turbulent intensity and so on. The fluctuation of those error factors are acquired from experiments and simulation. Based on these data, the uncertainty is established for material removal ratio, showing that the theoretical uncertainty accords with the experiments′ error. Polishing precision can be improved by error factors′ compensation..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 112012 (2011)
Integrated Optics
Slow Light Waveguide with Low Group-Velocity Dispersion and Low Loss in 2-D Photonic Crystal
Zhang DongZhao, JianlinLü, and Shuyuan
An analysis on the transmission properties of the light in 2-D photonic crystal coupled cavity waveguide (CCW) with triangular lattice structured by columned media and air background is presentod using plane wave expansion (PWE) method. The numerical simulation results show that, the group velocity of the guide model dAn analysis on the transmission properties of the light in 2-D photonic crystal coupled cavity waveguide (CCW) with triangular lattice structured by columned media and air background is presentod using plane wave expansion (PWE) method. The numerical simulation results show that, the group velocity of the guide model decreases quickly with increasing the distance between the defect cavities. Considering both the dispersion and loss of the CCW, it was found that when the distance between the defect cavities is taken as double of the lattice constant, the transmittance per mm of the CCW, the bandwidth and the effective group refractive index would be 47%, 1.97 GHz and 22.4, respectively. The property of group-velocity dispersion (GVD) of the slow light was analyzed. It is found that the magnitude of the GVD value in the area of slow light is 10-2, meaning that the structure has the best slow-light characteristic and allow the slow light propagate efficiently. Based on this CCW structure a low loss optical delayer was proposed, the calculation results show that this delayer is able to achieve a delay time of 9.4 ps and a loss of lower than 1 dB..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 113001 (2011)
Slow-Light Characteristics of Photonic Crystal Waveguides
Qu Lianjie, Yang Yuede, and Huang Yongzhen
Based on two-dimensional triangular lattice air-hole photonic crystal, a kind of waveguide structure with good slow-light characteristics is proposed by inducing coupled-cavity on both sides of the photonic crystal single-line defected waveguides. The energy-band structure, group velocity and group-velocity dispersion Based on two-dimensional triangular lattice air-hole photonic crystal, a kind of waveguide structure with good slow-light characteristics is proposed by inducing coupled-cavity on both sides of the photonic crystal single-line defected waveguides. The energy-band structure, group velocity and group-velocity dispersion characteristics of slow-light mode are analyzed by plane wave expansion method. For the waveguide structure using single-defect cavity as coupled cavity, the group velocity of 0.0128c at the zero-dispersion point with the bandwidth of 409 GHz in the 1.55 μm wavelength could be obtained by appropriately adjusting the waveguide width. As for the waveguide structure using two-defect cavity as coupled cavity with the super-cell of 4a×9b, the group velocity can reach 0.0070c at the zero-dispersion point with the bandwidth of 226 GHz in the 1.55 μm wavelength by adjusting the waveguide width. To further increase the distance between the two-defect cavities, the slow-light mode with group velocity of 0.0011c at the zero-dispersion point could be obtained. Besides, the slow-light waveguide can meet different requirements by selecting the appropriate width of waveguide..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 113002 (2011)
Machine Vision
Uniform Illumination Study by Light-Emitting Diode Ring Array and Diffuse Reflection Surface
Zhu Zhenmin, Qu Xinghua, Liang Haiyu, and Jia Guoxin
Well mixed-color distribution of illumination and uniform illuminated environment are the common requirements in color vision applications. Using three-ring light-emitting diode (LED) array and diffuse reflection surface, an indirection method for the uniform illumination is proposed, and a mathematic simulation algoriWell mixed-color distribution of illumination and uniform illuminated environment are the common requirements in color vision applications. Using three-ring light-emitting diode (LED) array and diffuse reflection surface, an indirection method for the uniform illumination is proposed, and a mathematic simulation algorithm is constructed. Based on the Lambertian characteristic of a sing LED, the irradiance distribution over a sphere inner surface to the three-ring LED array is discussed. Then light is reflected to the detected surface by sphere inner surface. The sphere inner surface with high diffuse reflectance can be seemed as a Lambertian surface. According to bi-directional reflectance distribution functions (BRDF) of sphere inner surface, the uniformity of irradiance distribution of detection surface is simulated. Experimentd are implemented to check the validity of simulation results and the indirection method. Some experimental images show uniform mixed-color distribution and the illumination uniformity of 95.5% can fulfill the meets of color vision applications. The experimental results confirm that this method is useful for the uniform illumination design..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 115001 (2011)
Novel Grating Projection System Based on Assistant Line and its Calibration Method
Wang Tao, Sun Changku, Shi Yongqiang, and Wang Peng
The structure of the traditional grating projection system is difficult to construct for its rigid geometry constraints. In addition, the reference plane is inevitably employed in the system which limits the range of the measurement and the application. In order to resolve the above problems, an assistant line is introThe structure of the traditional grating projection system is difficult to construct for its rigid geometry constraints. In addition, the reference plane is inevitably employed in the system which limits the range of the measurement and the application. In order to resolve the above problems, an assistant line is introduced to the system. The equation of translation from relative phase to absolute phase is deduced according to the assistant line. Space mapping method and its optimization algorithm are employed, by which the object′s real 3D data can be calculated. A circle liner target is designed, with which the extraction of feature points, target phase and feature line can be accomplished by only one image, and the procedure of the calibration is simplified. Last, the profile of a plaster model is measured by the system with two images, and the accuracy of the result is proved, the mean-square deviation (MSE) of the distance between ten shifting planes is 0.02 mm, and the MSE of the angle between ten rotating planes is 0.03°. The experiment shows that the method is accurate, fast, and easy to construct and calibrate, which has improtant application values..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 115002 (2011)
Variable Domain Algorithm for Image Segmentation Using Statistical Models Based on Intensity Features
Gao Xiaoliang, Wang Zhiliang, Liu Jiwei, Cui Chaohui, and Wang Lu
Image segmentation technology is an important part of the lower level of computer vision. It′s also a basic precondition for image analysis and pattern recognition. It has been widely used in many fields such as medical images and remote sensing images. Meanwhile, image segmentation is a difficulty in image processing Image segmentation technology is an important part of the lower level of computer vision. It′s also a basic precondition for image analysis and pattern recognition. It has been widely used in many fields such as medical images and remote sensing images. Meanwhile, image segmentation is a difficulty in image processing as well. Aiming at medical imagery, a novel variational domain approach to curve evolution for image segmentation is proposed based on a statistical active contour model using level sets. The essential idea is to re-define the computing domain in image repeatedly by separating the segmentation procedure into several individual phases. By our algorithm, the work can be done automatically without manual intervention. Moreover, compared with current methods, the rapidity can be enhanced effectively for the objects with complicated topology..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 115003 (2011)
Materials
Fluorescent Properties of 7-Hydroxy-4-Trifluoromethylcoumarin Incorporated in Mesoporous AlPO4 Glass
Li Rihong, Fan Youyu, Fan Jintai, and Zhang Long
7-hydroxy-4-trifluoromethylcoumarin (7-coumarin) incorporated in mesoporous AlPO4 glass is prepared with dipping method. The effects of 7-Coumarin concentration and pore size of AlPO4 glass on the optical properties and molecular formation of 7-Coumarin are studied by excitation spectra and emission spectra. The main e7-hydroxy-4-trifluoromethylcoumarin (7-coumarin) incorporated in mesoporous AlPO4 glass is prepared with dipping method. The effects of 7-Coumarin concentration and pore size of AlPO4 glass on the optical properties and molecular formation of 7-Coumarin are studied by excitation spectra and emission spectra. The main excitation band placed at 372 nm is ascribed to monomeric 7-Coumarin in excitation spectra, and the blue shift of main excitation band is due to the aggregating of fluorescent dimers in the mesoporous glass as 7-Coumarin concentration increases from 1×10-6 mol/L to 1×10-2 mol/L. Red shift of emission band from 421 nm to 435 nm is observed in emission spectra as 7-Coumarin concentration increases from 1×10-6 mol/L to 1×10-2 mol/L. The emission spectra and excitation spectra of two different mesoporous AlPO4 glass with the loading dyes concentration 1.0×10-4 mol/L are studied to investigate the effects of pore size on the optical properties. The blue shift of excitation band from 370 nm to 365 nm, as well as red shift of emission band from 428 nm to 433 nm are observed as the pore diameter of the AlPO4 glass increased from 3.52 nm to 6.74 nm, which reveals less aggregates as H-dimers in the AlPO4 mesoporous glass with smaller pore diameter and that can benefit for loading the dyes in high concentration..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 116001 (2011)
Growth and Spectral Properties of Tm:YLiF4 Crystals
Chen Guangzhu, Hang Yin, Peng Haiyan, Zhang Lianhan, Yin Jigang, Xiong Jing, He Xiaoming, and Xu Jianqiu
High optical quality 2% number fraction of thulium replacemented yttrium atoms Tm:YLiF4 (YLF) crystal is successfully grown by the Czochralski technique with the medium frequency induction heating furnace. The structure of TmYLF crystal is determined by the precise X ray diffraction (XRD) measurement. And the spectral High optical quality 2% number fraction of thulium replacemented yttrium atoms Tm:YLiF4 (YLF) crystal is successfully grown by the Czochralski technique with the medium frequency induction heating furnace. The structure of TmYLF crystal is determined by the precise X ray diffraction (XRD) measurement. And the spectral properties of TmYLF crystal are studied and analyzed by absorption and fluorescence spectra. Absorption coefficient and absorption section of Tm ion at different wavelengths are calculated. At room temperature, TmYLFslabs made by 2% thulium-doped single crystal are end-pumped by a laser diode stack at wavelength of 793 nm. Laser output of 54.4 W continuous wave power at 160 W input power is achieved, corresponding to an optical efficiency of 31.2%..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 116002 (2011)
Nonlinear Optics
Study on Noncollinear Phase Matching in YCOB Crystal
Sun Meizhi, Bi Qunyu, Zhang Fuling, Kang Jun, Xie Xinglong, and Lin Zunqi
The non-collinear phase matching in XOY and XOZ principal planes of yttrium calcium oxyborate (YCOB) crystal is analyzed in detail with signal pulse of central wavelength at 1053 nm and pump pulse of wavelength at 532 nm. Based on the concepts without numerical approximation, the optimal noncollinear angles, phase-matcThe non-collinear phase matching in XOY and XOZ principal planes of yttrium calcium oxyborate (YCOB) crystal is analyzed in detail with signal pulse of central wavelength at 1053 nm and pump pulse of wavelength at 532 nm. Based on the concepts without numerical approximation, the optimal noncollinear angles, phase-matching angles, parametric bandwidths, walk-off angles, acceptance angles, efficiency coefficients, and gain bandwidths are presented. It is concluded that the YCOB crystals have broad gain bandwidth, high gain, big acceptance angle and small walk-off angle, and they can be utilized as gain media both in high-energy high-power solid-state lasers and tens of femtoseconds ultra-short pulsed laser systems..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 119001 (2011)
Optical Devices
A Beam Steering Approach of Liquid Crystal Phased Array Based on Nonperiodic Blazed Grating
Kong Lingjiang, Zhu Ying, Song Yan, and Yang Jianyu
Periodic blazed grating of binary grating limits the number and distribution of the diffraction angles realized by liquid crystal phased array (LCPA). Inspired by microwave radar phase arrays theory, a beam steering approach of liquid crystal phased array based on a nonperiodic blazed grating is proposed. Through the dPeriodic blazed grating of binary grating limits the number and distribution of the diffraction angles realized by liquid crystal phased array (LCPA). Inspired by microwave radar phase arrays theory, a beam steering approach of liquid crystal phased array based on a nonperiodic blazed grating is proposed. Through the deduction of diffraction theory, it is verified that periodic blazed grating is a special case of nonperiodic blazed grating. Simulations are presented to testify that the beam steering approach based on nonperiodic blazed grating can obtain steering angles which are ten times as many as those produced by periodic blazed grating. Without combining with other devices, LCPA can realize continuous beam steering of almost all the resolvable spots over the field of view and will not decrease diffraction efficiency. In order to validate the proposed approach, beam steering experiment is performed with single LCPA. The results show that the beam steering approach based on nonperiodic blazed grating can obtain continous beam steering and steering angles which periodic blazed grating cannot..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 123001 (2011)
Properties of Photon Counting Imaging Detector with Au Photocathode
Liu Yongan, Zhao Feifei, Hu Huijun, Sheng Lizhi, Yan Qiurong, and Zhao Baosheng
Au photocathode is used in photon counting imaging system with induction readout. A 15 nm gold film is deposited on the resolution test board and it is used for transmission photocathode. The gain performance of micro-channel plates (MCP), resolution and counting rate of the detector with Au photocathode are tested. ThAu photocathode is used in photon counting imaging system with induction readout. A 15 nm gold film is deposited on the resolution test board and it is used for transmission photocathode. The gain performance of micro-channel plates (MCP), resolution and counting rate of the detector with Au photocathode are tested. The results show that the system with Au cathode has a quasi-Gaussian pulse height distribution (PHD) curves. The peak of the PHD curves moved to the high-gain zone and the full width at half maximum (FWHM) gradually widened as the voltage increased. After the adoption of Au cathode, the detection efficiency and the signal-to-noise ratio of photon counting imaging detector effectively improved. The resolution test results show that the spatial resolution of the detector is better than 75 μm, and the counting rate can reach 13.5 kHz when the system′s resolution is better than 150 μm..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 123002 (2011)
Research on the Characteristics of Sub-Wavelength Grating Color Filter
Zhou Yun, Ye Yan, Shen Su, Fang Zongbao, Pu Donglin, and Chen Linsen
Transmission characteristic of a novel sub-wavelength grating color filter at visible region is investigated theoretically. The device consists of three parts: the flexible transparent substrate, the dielectric grating and the metal grating. By using rigorous couple-wave analysis (RCWA), the transmission characteristicTransmission characteristic of a novel sub-wavelength grating color filter at visible region is investigated theoretically. The device consists of three parts: the flexible transparent substrate, the dielectric grating and the metal grating. By using rigorous couple-wave analysis (RCWA), the transmission characteristic is analyzed as a function of the duty cycle, the thickness of the dielectric grating, the thickness of the metal grating and the period. Based on the simulation results, a high-performance color filter is proposed by optimizing the structural parameters. The bandwidth of the filters are about 85 nm. The peak transmission efficiency of the filters are about 95%. The calculated results show that the peak transmission efficiency of the filters are increased more than 12% compared with the previous color filters incorporating a grating. The overlap of the tricolor output spectra decreases effectively, which will increase the color saturation of the color filter. The proposed color filter is suitable for filtering used in liquid crystal devices..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 123003 (2011)
OPTOELECTRONICS
Analysis of Output Characteristics of Super Cells Serial Module with Partial Shading
Li Guoliang, Li Ming, Wang Liuling, Xiang Ming, Huang Bo, Zheng Tufeng, Wei Shengxian, and Wang Yunfeng
Based on a circuit model of a photovoltaic (PV) cell with an extension term considering avalanche effect, the model of PV module with partial shading is established for the analysis of shadow effect. The validity of the model is verified with outdoor experimental test under real solar radiation condition. The output chBased on a circuit model of a photovoltaic (PV) cell with an extension term considering avalanche effect, the model of PV module with partial shading is established for the analysis of shadow effect. The validity of the model is verified with outdoor experimental test under real solar radiation condition. The output characteristics of one super cell at reverse bias-voltage, the I-V characteristics, P-V characteristics and yield of the serial module under different shadow block are analyzed by use of the model. The results indicate that the maximum output power drops 40% when the serial module has 40% partial shading. The output power of the module declines rapidly with shading increasing of one super cell. The maximum power decrease 7.36%, 25.81% and 97.94% respectively when each cell is shaded 1/5, 2/5 and the whole..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 125001 (2011)
Quantum Optics
Electromagnetically Induced Transparency of Four-Level Atomic System in a Field of Time-Varying Frequenry
Cai Xunming
When two optical fields interact with a four-level N type atom, there are three transitions and the middle transition is used as a probe transition. The two field are called coupled fields and probe field. Two cases of electromagnetically induced transparency (EIT) are discussed. When the frequency changes with time inWhen two optical fields interact with a four-level N type atom, there are three transitions and the middle transition is used as a probe transition. The two field are called coupled fields and probe field. Two cases of electromagnetically induced transparency (EIT) are discussed. When the frequency changes with time in sinusoidal form, the frequency of electromagnetically induced transparency won′t change but the degree of EIT will change with time periodically. When the frequency changes with time in rectangular form, the frequency will change, the frequency shift can be calculated by the formula proposed in the article. The amplitude of EIT changing with time periodically-energy increases when the modulation amplitude of these rectangular pulses is increased..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 127001 (2011)
Remote Sensing and Sensors
Fresnel Telescope Full-Aperture Synthesized Imaging Ladar: Principle
Liu Liren
An idea of Fresnel telescope full-aperture synthesized imaging ladar is proposed, which is based on the optoelectronic data collection from the relative scanning between target and two cocentric coaxial beams of polarization-orthogonal quadratic wavefronts, and the image reconstruction from the complex quadratic phase An idea of Fresnel telescope full-aperture synthesized imaging ladar is proposed, which is based on the optoelectronic data collection from the relative scanning between target and two cocentric coaxial beams of polarization-orthogonal quadratic wavefronts, and the image reconstruction from the complex quadratic phase decoded with optics and digital processing. It has two operational modes with moving target by 1D beam scanning and statistic target by 2D scanning. The imaging resolution is higher than that from the diffraction limit and 3D imaging is also possible. Because of the transformation of spatial signal to temporary signal and the utilization of coherent detection of coaxial beams, both the imaging S/N ratio and the receiving sensitivity are improved, and particularly the atmospheric influence is decreased greatly, optical receiving system of low quality is allowed to use to increase optical receiving aperture and decrease laser transmitting power. The systematic optoelctronic and mechanical configuration is quite simple due to the use of an optical hybrid. The detailed description of principle and mathematical analysis is given..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 128001 (2011)
Spectroscopy
Variation Trend of Three-Dimensional Fluorescence Characteristics of Aromatic Organic Pollutants in the ABS Wastewater Treatment Process
Lai Bo, Zhou Yuexi, Dou Lianfeng, Qin Hongke, Sun Lidong, and Cheng Jiayun
The ABS resin wastewater was treated by biological activated carbon and sequencing batch reactor(BAC-SBR), and the variation trend of three-dimensional fluorescence spectra, chemical oxygen demand (COD) and total organic carbon of (TOC) for ABS resin wastewater was detected in the treatment process. The difference of fThe ABS resin wastewater was treated by biological activated carbon and sequencing batch reactor(BAC-SBR), and the variation trend of three-dimensional fluorescence spectra, chemical oxygen demand (COD) and total organic carbon of (TOC) for ABS resin wastewater was detected in the treatment process. The difference of fluorescence fingerprint for ABS resin wastewater and typical municipal wastewater was studied comparatively. The correlation of total fluorescence intensity removal ratio with the removal ratio of COD and TOC for ABS wastewater was studied intensively in the treatment process. The results show that the fluorescence fingerprint (the ratio of Peak A/Peak B) of ABS wastewater is 0.124, which is much lower than that of typical municipal wastewater (about 1.6). In the whole treatmet process, the total fluorescence intensity removal ratio has good linear relation with the removal ratio of COD and TOC, and their corelation coefficient were 0.98 and 0.99, respectively. Therefore the removal ratio of the aromatic organic pollutants in wastwater could be analysed by the determination of the change of fluorescence intensity..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 130001 (2011)
Properties of Laser-Induced Breakdown Spectroscopy between Liquid Steel and Solid Steel
Dong Meirong, Lu Jidong, Li Jun, Chen Kai, Pan Shenghua, Yao Shunchun, and Li Junyan
In order to deeply understand the detection mechanism of determining the components content of liquid steel using laser-induced breakdown spectroscopy, the 45# steel is used to study the different properties between liquid state and solid state which is cooled after solidification. It indicats that the direct measuremeIn order to deeply understand the detection mechanism of determining the components content of liquid steel using laser-induced breakdown spectroscopy, the 45# steel is used to study the different properties between liquid state and solid state which is cooled after solidification. It indicats that the direct measurement stability of liquid steel is poorer than that of the solid steel. The spectrum intensities of liquid steel are significantly stronger than those of the solid steel and the plasma characteristics of them are significantly different. Five iron atomic spectra lines are used to calculate the plasma temperature and a silicon atomic spectra line of 390.55 nm is chosen to estimate electron density. The results show that the plasma temperature and electron density of liquid steel are both stronger than those of the solid steel. The differences of temperature and physical form contribute the differences of plasma and spectral characteristics between liquid steel and solid steel..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 130002 (2011)
Thin Films
Study on Extraordinary Optical Transmission through Arrays of Holes Metal Films Based on Scattering Matrix Method
Yuan Xiaodong, Liu Ken, Ye Weimin, Zhang Jianfa, and Zeng Chun
Scattering matrix method is a research method in frequency domain. Transmission spectra of metal films with periodic air holes is studied based on this method. Copper slabs etched with periodic square lattice of air holes are used. Lorentz-Drude model is used to describe permittivity ε of copper. Transmission spectra aScattering matrix method is a research method in frequency domain. Transmission spectra of metal films with periodic air holes is studied based on this method. Copper slabs etched with periodic square lattice of air holes are used. Lorentz-Drude model is used to describe permittivity ε of copper. Transmission spectra are obtained for different thicknesses of copper slabs, different lattice constants and different radii of air holes. The results agree well with the results obtained by finite-difference time-domain method (FDTD). It is shown that while light cannot be transmitted thought metal slabs, extraordinary optical transmissions can be observed if metal slabs are drilled with periodic air holes. This is mainly caused by surface plasmon resonance in the metal photonic crystal slabs. Results can be verified by comparing them obtained from the scattering matrix method in frequency domain and the FDTD method in time domain. Thus it can reduce the cost to verify the results experimentally and enhance the ability of simulation..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 131001 (2011)
Magnetic Polarization of Co/PAA in Adjustable Magnetic Field
Zheng Mengmeng, Liu Zaiguo, Wu Wendi, Song Lianke, and Xu Hui
Highly ordered porous anodic aluminum oxide (PAA) membranes are prepared by electrochemical method. By alternating current electrodepositing, Co nanowire arrays are fabricated in the porous anodic alumina (PAA) in an electrolyte CoSO4. The morphology and microstructures of Co/PAA are characterized by SEM and X-ray diffHighly ordered porous anodic aluminum oxide (PAA) membranes are prepared by electrochemical method. By alternating current electrodepositing, Co nanowire arrays are fabricated in the porous anodic alumina (PAA) in an electrolyte CoSO4. The morphology and microstructures of Co/PAA are characterized by SEM and X-ray diffraction. The results show that Co nanowires are indeed synthesized in porous alumina, and the nanowires have a preferred crystal face (100) during growing. The optical system is established in which the changes of polarization state for sample can be measured. In this optical system, the depolarization effect in Co/PAA which often be used in optical isolator is measured in large variation range of adjustable magnetic field. The experiment result shows that Co/PAA has depolarization effect in adjustable magnetic field, and the polarization performance is best in Co/PAA when it reaches saturated magnetization. The depolarization effect is occured when the intensity of magnetic field increases over saturation intensity. The principle for magnetic depolarization effect is also given according to the experimental result..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 131002 (2011)
Morphology Analysis of ZnO:Ga Thin Films Deposited by Pulsed Laser Deposition
Liu Yunyan, Cheng Chuanfu, Song Hongsheng, Zang Yongli, and Yang Shanying
The quantitative study on the film surface morphology is important for the understanding of thin film growth mechanism. The ZnO:Ga (GZO) transparent conductive film is prepared by pulsed laser deposition (PLD). Since this GZO film growth is far from equilibrium, the GZO film has self-affine fractal characteristics and The quantitative study on the film surface morphology is important for the understanding of thin film growth mechanism. The ZnO:Ga (GZO) transparent conductive film is prepared by pulsed laser deposition (PLD). Since this GZO film growth is far from equilibrium, the GZO film has self-affine fractal characteristics and can be described by height-height correlation function H (r, r+ρ). By using atomic force microscope to get the height data of the surface image, the quantitative analysis of height-height correlation function of the GZO film prepared by PLD is carried out. The values of the three important parameters W, ξ and α are measured and it is suggested that the growth of GZO thin film is consistent with Kuromoto-Sivashinsky growth model..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 131003 (2011)
Study on the Preparation and Properties of the Nonlinear Optical Polymer Containing Tricyanofuran Units
Han Likun, Jiang Yadong, and Li Yuanxun
A novel nonlinear optical polymer (P1) containing tricyanofuran units is synthesized by Friedel-Crafts reaction. The polymeric films are then fabricated by means of the spin-coating method, and the alignment of the chromophores of the polymeric film is carried out by corona poling method. The poling behaviors of the fiA novel nonlinear optical polymer (P1) containing tricyanofuran units is synthesized by Friedel-Crafts reaction. The polymeric films are then fabricated by means of the spin-coating method, and the alignment of the chromophores of the polymeric film is carried out by corona poling method. The poling behaviors of the films are studied by UV-visible absorption spectra and atomic-force microscopy (AFM). From the absorbance change, the order parameter (Φ=0.20) of the poled film can be estimated. The second-order nonlinear optical properties of the polymer are measured by the second harmonic generation (SHG), and the obtained value of the second harmonic coefficient d33=9.4 pm/V. The sample is stored at room temperature for 2 d, and the value of d33 is remained at 70% of the initial value. The experimental results show that compared with the host-guest adulterant polymer, P1 possesses competitive optical nonlinear stability..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 131004 (2011)
Piezo-Optical Effect of Polymer Dispersed Liquid Crystal Films
Fan Zhixin, Xie Yijun, Wei Xiangdong, Xie Huijie, Song Xinhua, Wang Dan, and Sun Yubao
It is reported that polymer dispersed liquid crystal (PDLC) films are transparency when pressed, and it is called piezo-optical effect of PDLC films. The concepts of stressed liquid crystal, sheared liquid crystal and stretched liquid crystal for PDLC films are described respectively. The pictures of piezo-optical effeIt is reported that polymer dispersed liquid crystal (PDLC) films are transparency when pressed, and it is called piezo-optical effect of PDLC films. The concepts of stressed liquid crystal, sheared liquid crystal and stretched liquid crystal for PDLC films are described respectively. The pictures of piezo-optical effect, polarized photographs of PDLC films, spectral analysis of electro-optical property and spectral analysis of piezo-optical effect are given. The principle of piezo-optical effect of PDLC films is also proposed, which believes that only if liquid crystal molecules in each micro-droplet are well orientated, the PDLC films will show transparency, no matter liquid crystal molecules in different droplets are well orientated or not. The piezo-optical effect of PDLC films poses questions to basic sciences of liquid crystal and may be applied in a lot of new press-optical applications without electricity (press-windows, functional glass, optical fiber press sensor, etc.)..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 131005 (2011)
Vision, Color, and Visual Optics
Investigation of Color Discrimination Threshold Characteristics Under Different Chromatic Backgrounds
Zeng Wang, Xu Haisong, Wang Zhehong, and M. Ronnier Luo
In order to investigate the influence of different chromatic backgrounds on the color discrimination characteristics, the psychophysical experiment based on the interleaved staircase method is carried out on the CIE1976L*a*b* plane to obtain the color discrimination thresholds at the five CIE color centers under these In order to investigate the influence of different chromatic backgrounds on the color discrimination characteristics, the psychophysical experiment based on the interleaved staircase method is carried out on the CIE1976L*a*b* plane to obtain the color discrimination thresholds at the five CIE color centers under these five different background colors respectively. Detailed analysis on the fitted discrimination threshold ellipses indicates that the local visual uniformity, as a whole, is stable at the same color centre under different background colors, and the semi-axis ratios of individual chromatic ellipses at different color centers shows similar trends against the hues of background colors. The color discrimination sensitivity is highest when the colors of the center and the background are the same, which implies evidently the crispening effect. For the cases of red and blue centers or of yellow and blue backgrounds, the human color discrimination characteristics are less affected at the red-green direction than the yellow-blue direction..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 133001 (2011)
Investigation of Chromatic Contrast Sensitivity Based on Different Color Directions and Spatial Frequencies
Lü Weige, Xu Haisong, Wang Zhehong, and M. Ronnier Luo
Based on the interleaved staircase method, the psychophysical visual experiment is carried out to investigate the spatial and color directional characteristics of chromatic contrast sensitivity. For the spatial frequencies from 0.5 to 11.7 cycle /(°) under the viewing field of 6° and 10°, the chromatic cBased on the interleaved staircase method, the psychophysical visual experiment is carried out to investigate the spatial and color directional characteristics of chromatic contrast sensitivity. For the spatial frequencies from 0.5 to 11.7 cycle /(°) under the viewing field of 6° and 10°, the chromatic contrast sensitivity which is defined as the reciprocal of the color-difference threshold is measured in 6 color directions in the iso-luminance plane of CIELAB color space at the two color centers of gray and red. The low-pass chromatic contrast sensitivity functions (CSF) of different color directions are compared, and the chromatic contrast threshold ellipses of different frequencies are fitted. With the increase of spatial frequency, the ellipse rotate with larger sizes and change ratio of semi-axis, which results in the change of chromatic contrast sensitivity with spatial frequencies and color directions, and implies the change of color appearance with the spatial frequencies. With the increase of viewing field, the ellipses′ peak azimuths and the fluctuation bands of semi-axis ratio shift to the lower frequencies, the tendency of which for red center is similar, but with lower values, to that of gray center under the same viewing field..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 31, Issue 1, 133002 (2011)
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