Contents
2015
Volume: 35 Issue 7
52 Article(s)
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Atmospheric Optics and Oceanic Optics
Technology of Laser Large-Footprint Multi-Objective Relative Distance Information Extraction and Verification
Lan Xiaoping, Huang Genghua, Wang Haiwei, and Wu Jun
In order to extract the relative elevation information of multi-objects from the echo waveform of the spaceborne earth observing laser altimeter with large- footprint, a Levenberg- Marquardt- based Gaussian decomposition algorithm is used to separate the waveforms, and a full-waveform acquisition system is developed foIn order to extract the relative elevation information of multi-objects from the echo waveform of the spaceborne earth observing laser altimeter with large- footprint, a Levenberg- Marquardt- based Gaussian decomposition algorithm is used to separate the waveforms, and a full-waveform acquisition system is developed for multi-objects. Experiments on the ground-based multi-objective distance information acquisition are carried out to verify the decomposition algorithm. The experimental results show that the calculated relative distance error of multi-objectives is less than 0.03 m which reveals the effectiveness of algorithm in separating multi-objects from echo waveforms and the validity of the large-footprint full-waveform acquisition system for expracting the relative distance informention of mulit-objects. The research is useful for the design of space-borne laser altimeter system and the study of data processing algorithm..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 701001 (2015)
Influence of Atmospheric Visibility on Laser Pulse Delay andBroadening in Sand and Dust Weather
Wang Huiqin, Wang Yangang, Cao Minghua, and Ke Xizheng
Based on the theory of optical signal transmitting in discrete medium, the two- frequency mutual coherence function and impulse response are derived for laser pulse delay and broadening problem in sand and dust weather, respectively. The relationship of laser pulse delay and broadening to atmospheric visibility in sandBased on the theory of optical signal transmitting in discrete medium, the two- frequency mutual coherence function and impulse response are derived for laser pulse delay and broadening problem in sand and dust weather, respectively. The relationship of laser pulse delay and broadening to atmospheric visibility in sand and dust weather is presented. In particular, the time delay and broadening is analyzed when the laser pulse wavelength is 3.8, 7.6 and 10.6 μm. Simulation results show that when using a specific laser wavelength, the laser pulse delay and broadening will decrease in a negative exponent form with the increase of atmospheric visibility and eventually converged to a definite value. Moreover, the laser pulse delay and broadening will increase with the laser wavelength increasement under a certain atmospheric visibility..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 701002 (2015)
Impact of Geometric Layouts of Laser Transceiver on the Correlation of Angle-of-Arrival Fluctuations
Huang Kai, Zhou Yu, Li Rongwang, Zhai Dongsheng, and Xiong Yaoheng
Tip-tilt disturbance of atmospheric turbulence leads to the angle-of-arrival fluctuations when a beam is propagating through such an atmosphere. The laser beam is propagating through the turbulent atmosphere twice in the cases of satellite laser ranging and laser guide star. Different locations of geometric layouts of Tip-tilt disturbance of atmospheric turbulence leads to the angle-of-arrival fluctuations when a beam is propagating through such an atmosphere. The laser beam is propagating through the turbulent atmosphere twice in the cases of satellite laser ranging and laser guide star. Different locations of geometric layouts of laser transceiver lead to the difference in correlation of tip-tilt fluctuations between laser launch and receive paths, and affect the variations of angle-of-arrival fluctuations in the end. Based on the geometry of laser transceiver, the tip-tilt correlation between two separated apertures is developed by using the wavefront expansion on the Zernike polynomials. The changes of the tip-tilt correlation due to the geometrical limit of common optical path system and non-common optical path system are analyzed. Finally, the impacts of geometric layouts of the different laser transceivers on the angle-of-arrival fluctuations are discussed..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 701003 (2015)
Simulation of the Scintillation Index of Plane Wave Propagating through General Non-Kolmogorov Atmospheric Turbulence Path
Li Yujie, Zhu Wenyue, Qian Xianmei, and Rao Ruizhong
The scintillation index of plane wave propagating through weak turbulent atmosphere, which contains Kolmogorov turbulence and non-Kolmogorov turbulence, are studied by using the numerical methods. The impacts of propagation distance on the irradiance scintillation index are analysed, and the impacts of spectral power lThe scintillation index of plane wave propagating through weak turbulent atmosphere, which contains Kolmogorov turbulence and non-Kolmogorov turbulence, are studied by using the numerical methods. The impacts of propagation distance on the irradiance scintillation index are analysed, and the impacts of spectral power law values and the percentage of non-Kolmogorov are also considered. The scintillation effects of plane wave propagation in mix turbulent path and in single turbulent path with Kolmogorov turbulence or non-Kolmogorov turbulence are compared. The results show that the scintillation index increases with the percentage of non-Kolmogorov turbulence increasing for one spectral power law, while Kolmogorov turbulence does the opposite in conditions of mix turbulent path. Besides, as the power law increases, the non-Kolmogorov scintillation index increases with power law up to the peak value, and then decreases with the further increase in power law in weak turbulent atmosphere..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 701004 (2015)
Study on Airborne Laser Bathymetric System Receiver Field of View
Li Kai, Zhang Yongsheng, Liu Xiaodi, and Tong Xiaochong
The effect of receive field of view (FOV) on laser sounding echo signals is analyzed based on“multipleforward scattering and single-backscattering”laser sounding echo signal mathematical model. The relationship between the FOV loss factor and the receiver FOV is discussed under different depths. D -index of discriminabThe effect of receive field of view (FOV) on laser sounding echo signals is analyzed based on“multipleforward scattering and single-backscattering”laser sounding echo signal mathematical model. The relationship between the FOV loss factor and the receiver FOV is discussed under different depths. D -index of discriminability of airborne laser bathymetric system is served as a performance evaluation criterion and the relationship between it and receiver FOV is analyzed. Further, the optimal FOV for different maximum detection depths is derived. The result in this paper can contribute to the optimization of FOV of airborne laser bathymetric system. Thus theoretical basis for the development of new airborne laser bathymetry system is provided..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 701005 (2015)
Detectors
Study on Discharge Characteristics of a Direct Current-Voltage Excited Plasma Jet
Li Xuechen, Chu Jingdi, Bao Wenting, Zhang Qi, and Jia Pengying
A needle-copper plate device excited by a direct current (DC) voltage is used to produce a nonequilibrium low temperature plasma plume at atmospheric pressure. Through optical method, it is found that the plasma plume discharge is pulsed. The total light emission signal is compared with the emission signal of 337.1 nm A needle-copper plate device excited by a direct current (DC) voltage is used to produce a nonequilibrium low temperature plasma plume at atmospheric pressure. Through optical method, it is found that the plasma plume discharge is pulsed. The total light emission signal is compared with the emission signal of 337.1 nm spectral line and the discharge current signal, it is found that the pulse duration is the largest for the current signal, and it is the smallest for the emission signal of 337.1 nm spectral line. Furthermore, the discharge frequency is studied, and results show that the discharge frequency increases with increasing the applied voltage. By using a spectrometer, the intensity of 337.1 nm spectral line decreases with increasing gas flow rate. It increases firstly and then decreases with the increasing the voltage. All of these physical phenomena mentioned above are analyzed qualitatively by gas discharge mechanism. These findings are of great importance for the generation and applications of non-equilibrium low temperature plasma plume generated at atmospheric pressure..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 704001 (2015)
Diffraction and Gratings
An Accurate Method for Measuring Interference Fringe Period in Scanning Beam Interference Lithography System
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Interference fringe period is a very important parameter of phase locking in scanning beam interference lithography system (SBIL). According to the feature of the SBIL system, a method that period is measured by moving beam-splitter is proposed. Based on Gaussian beam propagation theory, theoretical error is analyzed. Interference fringe period is a very important parameter of phase locking in scanning beam interference lithography system (SBIL). According to the feature of the SBIL system, a method that period is measured by moving beam-splitter is proposed. Based on Gaussian beam propagation theory, theoretical error is analyzed. Period counting method is proposed to calculate fringe period. In order to make it easy for two-dimension stage design, measuring period by short-stroke linear stage’s assistance is put forward and experiments are done. The results show that: the method that measuring period by short-stroke linear stage’s assistance is feasible in principle. When fringe density is 1800 line/mm in SBIL system, period measurement repeatability is 1.08 ×10-5 (1σ). Data measured in exposure experiments is consistent with the model, then the feasibility of this method is verified..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 705001 (2015)
Transmission Analysis of Single Layer Sub-Wavelength Metal Gratings
Wang Zhiwen, Chu Jinkui, and Wang Qianyi
In order to understand the transmission phenomena of sub-wavelength metal gratings and the effect of grating parameters on polarization transmission, the polarization transmission is analyzed qualitatively based on the equivalent medium theory. The influence of the grating parameters on polarization transmission and thIn order to understand the transmission phenomena of sub-wavelength metal gratings and the effect of grating parameters on polarization transmission, the polarization transmission is analyzed qualitatively based on the equivalent medium theory. The influence of the grating parameters on polarization transmission and the reason why these influences generated are presented. The mechanism of the transmission peaks is analyzed quantitatively by using the Fabry-Pérot resonance theory. The accuracy of the two theories is carefully verified and analyzed. The qualitative and quantitative analysis of the transmission mechanism of sub-wavelength metal gratings will be helpful for better understanding of the effect of grating parameters on polarization transmission..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 705002 (2015)
Generation of Localized Hollow Beams with Photon Sieves
Cheng Yiguang, Liu Junbo, Hu Song, and He Yu
In order to find a simple and effective method for generation of hollow laser beams, a method of producing hollow beams with the photon sieve is proposed. The light of internal zones and external zones has destructive interference at the center of the focal plane, and hence the localized hollow beam is formed. ResearchIn order to find a simple and effective method for generation of hollow laser beams, a method of producing hollow beams with the photon sieve is proposed. The light of internal zones and external zones has destructive interference at the center of the focal plane, and hence the localized hollow beam is formed. Research on relationships between the dark spot diameter and focal length, annulus, modulation factor is carried out. Hollow beams with micron and submicron dark spot are obtained with proper focal length and annulus. The method is verified by theoretical derivation and simulation analysis. Results show that it has advantages of simple structure and minimal dark spot, especially suitable for optical tweezers, atom cooling and so on..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 705003 (2015)
Fiber Optics and Optical Communications
Research on Noise Cancellation Based on Acousto-Optic Effect in Coherent Detection
He Ning, Feng Taiqin, and Liao Xin
The grating theory of acousto-optic effect grating is studied. The relationship between momentum matching and diffraction efficiency is analyzed. The noise reduction mechanism of balance coherent detection is discussed. The system is designed and the relative experiment is test. Noise reduction technology based on acouThe grating theory of acousto-optic effect grating is studied. The relationship between momentum matching and diffraction efficiency is analyzed. The noise reduction mechanism of balance coherent detection is discussed. The system is designed and the relative experiment is test. Noise reduction technology based on acousto-optic effect in coherent balanced detection is verified. The result shows that in the interaction of the sound and light ,a stable grating could be established when the phase of signal is determined, and its diffraction efficiency is bigger than noise signal whose phase is random. By using balance detection, the influence of noise fluctuation to the system output is effective inhibited, and the signal noise ratio is improved..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 706001 (2015)
Refractive Index Sensing Characteristics of Cladding-Etched Elliptical Core Polarization Maitaining Fiber based on Intermodal Interference
Guo Xuan, Liu Feng, Xu Xiang, Fu Xinghu, Qi Yuefeng, and Tan Ailing
The refractive index sensing characteristics of the elliptical core polarization maitaining fiber(Ecore PMF) based on intermodal interference are investigated. The refractive index sensor probe is composed with a section of E- core PMF that etached by hydrofluoric acid. And the taper structure of sensor probe can be coThe refractive index sensing characteristics of the elliptical core polarization maitaining fiber(Ecore PMF) based on intermodal interference are investigated. The refractive index sensor probe is composed with a section of E- core PMF that etached by hydrofluoric acid. And the taper structure of sensor probe can be controlled by erosion time conveniently. The relationship of the two-lobe intensity distribution produced by the intermodal interference between the basic made and the first order higher mode of PMF with the analyte refractive index is analyzed comprehensively. Furthermore, the influence of the tapered area radius and the wavelength on the refractive index sensitivity is discussed deeply. The experiments demonstrate that the refractive index sensitivity of a refractive index sensor with 8 μm tapered area radius can reach - 7.1/RIU, which means the ratio between the normalized ralue and the refractive index unit (RIU), near 1.39 refractive index, when the laser source wavelength is 980 nm..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 706002 (2015)
Performance Analysis of New Hybrid Pulse Modulation Scheme in Optical Wireless System
Liu Hongzhan, Liao Renbo, Sun Jianfeng, and Liu Liren
The modulation technique is one of the important factors affected the quality of optical wireless communication. It need to find the appropriate modulation scheme, and it is necessary to analyze the performances of different pulse modulation schemes completely and deeply. The symbol structures of not only traditional mThe modulation technique is one of the important factors affected the quality of optical wireless communication. It need to find the appropriate modulation scheme, and it is necessary to analyze the performances of different pulse modulation schemes completely and deeply. The symbol structures of not only traditional modulation scheme like pulse position modulation (PPM) and digital pulse interval modulation (DPIM) but also new hybrid modulation scheme such as pulse position width modulation (PPWM), differential pulse position width modulation (DPPWM), dual- amplitude pulse position modulation and dual- amplitude pulse interval modulation (DAPIM) are analyzed in detail. The average transmission power and bandwidth efficiency for these above modulation schemes are also analyzed. At last, the error performances of these different modulation schemes are derived in detail. The numerical results show that the power utilization of DAPPM is the best and DPPWM’s is the worst; when the value of binary bits M is given, the bandwidth utilization of DPPWM is the best, but PPM’s is the worst. With the increase of M , the bandwidth utilization of DAPPM is near to DPIM’s. When the values of M and signal to noise ratio RSN are given, the packet error rate of DAPPM is near to PPM’s, but they are better than the others. The packet error rate is gradually reduced with the increase of M and RSN . At the same time, through the enlargement of r or the decrease of α , the error performances of PPWM and DAPPM are partly improved. Consequently, the appropriate modulation scheme is need to be selected according to the system’s demand..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 706004 (2015)
Holography
Lateral Shearing Digital Holography with Objective Translation to Eliminate Optical Phase Aberration
Pan Weiqing, and Gong Guofang
A lateral shearing digital holography to completely eliminate optical phase aberration is present. Based on three sequentially digital holograms by lateral translation, three phases are obtained from the holograms. The optical aberration is eliminated by subtracting the phases each other and two phase differences of thA lateral shearing digital holography to completely eliminate optical phase aberration is present. Based on three sequentially digital holograms by lateral translation, three phases are obtained from the holograms. The optical aberration is eliminated by subtracting the phases each other and two phase differences of the wavefront under test are obtained. Lastly, the objective three- dimensional phase without optical aberration is reconstructed through the phase differences based on Fourier expansion. An interferometer optical path in reflective configure is designed to demonstrate the proposed method. Two aberrational lenses are introduced into the path to produce unknown optical phase aberrations. The demonstration experiments are carried out without parallel calibration between the CCD plane and the test objective plane. In the experiments, the translation displacement is 0.02mm with the translation resolution of 0.01mm. The experimental results show that the root mean squared error is about λ 14 between the phase of the proposed method and the standard phase without aberration. The error sources are analyzed. The proposed lateral shearing digital holography can be used to ultra-precise optical measurement through eliminating optical phase aberration to increase the measurement resolution..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 709001 (2015)
Image Processing
Research and Implementation of Improved Neural Network Non-Uniformity Correction Algorithm
Duan Chengpeng, Liu Wei, Xie Qingsheng, Leng Hanbing, Yi Bo, and Chen Yaohong
In order to implement non-uniformity correction of infrared image, the neural network algorithm is commonly used to complete adaptive non-uniformity correction of infrared image at present, this method can update the correction factor automatically, but the algorithm is complex, and the correction output image contrastIn order to implement non-uniformity correction of infrared image, the neural network algorithm is commonly used to complete adaptive non-uniformity correction of infrared image at present, this method can update the correction factor automatically, but the algorithm is complex, and the correction output image contrast is low, the ghosting and image blurring appears. An improved neural network non- uniformity correction method is presented, the initial value of calibration coefficients are obtained by the use of high and low temperature blackbody, and the calculation of the output expect value in the iterative process is improved. The test results show that the method is simple and practical, and has a good non-uniform correction effect..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 710001 (2015)
Analysis of Focusing Camera Based on of Image Spectrum
Ma Lina, Zong Xiaoying, and Li Yongqiang
The imaging quality of camera severely depends on the precision of location of focal plane, and correlation research on the testing method is carried out. A testing method of locating focal length based on the image spectrum is presented, which can make use of at least two defocusing pictures from the same target to caThe imaging quality of camera severely depends on the precision of location of focal plane, and correlation research on the testing method is carried out. A testing method of locating focal length based on the image spectrum is presented, which can make use of at least two defocusing pictures from the same target to calculate the defocusing amount of camera image plane. And on the condition that the camera lens is aligned well with the design requirement,the target is random. In the process of numerical calculation using the similarity of two images, the image spectrum can avoid direct decomposition and make the testing easy, stable, reliable and with high precision..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 710002 (2015)
Imaging Systems
Dynamic Modulation Transfer Function Analysis and Research under Sinusoidal Vibration
Du Yanlu, Ding Yalin, Xu Yongsen, and Nie Pin
The image resolution of aerial camera declines resulting from vibration and the dynamic modulation transfer function(MTF) is used to evaluate the impact of vibration on image quality. In accordance with the transfer function theory of linear optical system, a formula based on Bessel function of the first kind is establThe image resolution of aerial camera declines resulting from vibration and the dynamic modulation transfer function(MTF) is used to evaluate the impact of vibration on image quality. In accordance with the transfer function theory of linear optical system, a formula based on Bessel function of the first kind is established to calculate dynamic MTF for sinusoidal vibration at any frequency. The tolerance of vibration amplitude is calculated with the restriction that dynamic MTF at Nyquist frequency is no less than 0.9. For low-frequency, the amplitude tolerance declines as frequency rises. And the tolerance of high-frequency is 0.2 pixel. The dynamic imaging experiment of the edge target under sinusoidal vibration is carried out. The experiment shows that the relative error between the MTFs calculated from the derived formula and the MTFs obtained by slanted-edge method from the practical degraded image is less than 4.25%. The accuracy rises 18.5 times compared with other relevant literature. Therefore, the proposed formula can be used to estimate and evaluate the image quality of aerial camera under vibration and is significant for the design of the line-of-sight stabilization system..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 711001 (2015)
Reflective Underwater Ghost Imaging
Xiang Qing, Yang Kecheng, Yu Long, Xia Min, Li Wei, and Guo Wenping
The quality of underwater imaging is restricted by laser power and receiver sensitivity. Existing ghost imaging method in free space can get higher resolution than traditional imaging detection. Based on theory of statistical optics and underwater optical properties, a two dimensional reflective underwater ghost imaginThe quality of underwater imaging is restricted by laser power and receiver sensitivity. Existing ghost imaging method in free space can get higher resolution than traditional imaging detection. Based on theory of statistical optics and underwater optical properties, a two dimensional reflective underwater ghost imaging method using pseudothermal light source is presented，a theoretical model is built to simulate the dynamic process of pseudothermal field variation and the optical fields modulation by target, and the light intensity fluctuate image of target is rebuilt. Experiment results agree well with the results of numerical simulations indicating that reflective ghost imaging pattern can be applied to underwater imaging..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 711002 (2015)
Study on Calculation Method of the Weighted Coefficient in X-ray Imaging Based on Variable Energy
Zhao Xia, and Liu Bin
X-ray radiographic imaging technology with variable energies acquires useful information of the object under tests in different thickness ranges by setting changing voltage parameters of the tubes. Such information are fused to show the complete internal structure of the object. In practical, the method to determine weX-ray radiographic imaging technology with variable energies acquires useful information of the object under tests in different thickness ranges by setting changing voltage parameters of the tubes. Such information are fused to show the complete internal structure of the object. In practical, the method to determine weighted coefficient of sub graphs based on tube voltage-thickness-device response curves in existing X-ray radiographic imaging experiments is passing out of current use, especially for composite materials. The reason is that the attenuation coefficient of the material and the fluorescence conversion efficiency of phosphor transform screen of materials are related to each other in energy spectra. A method of controlling varying steps of the tube voltages based on relations between adjacent tube voltages and effective transillumination thickness is presented by studying the gray changing rule of transillumination images under different voltages. And then, the proportion histogram is proposed to calculate the weighted coefficient. X-ray imaging of composite objects with variable energies shows experimentally that the mentioned method can realize fusion of effective sub-graphs of composite objects. It overcomes shortcomings of the existing image processing algorithms in X-ray radiographic imaging technology with variable energies..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 711003 (2015)
An Antenna can be Used for Terahertz Scanning Imaging
Wang Hanqi, Liu Xin, Deng Chao, and Zhang Cunlin
In order to overcome the shortcomings of the scanning antenna that is used in the current terahertz scanning imaging technology, a rectangular wave-guide antenna with inclined slits in the narrow side which can achieve one-dimensional frequency scanning is designed. Through applying the equivalent circuit method and thIn order to overcome the shortcomings of the scanning antenna that is used in the current terahertz scanning imaging technology, a rectangular wave-guide antenna with inclined slits in the narrow side which can achieve one-dimensional frequency scanning is designed. Through applying the equivalent circuit method and the Taylor line array method for designing slit antenna, the initial parameters such as slit spacing, slit width, slit length, slit inclination and slit number are estimated. Then, simulation and optimization are done in the ANSOFT-HFSS software. Finally, the antenna which is suitable for 0.101～0.111 THz bandwidth is achieved.The simulation results show that the antenna transmits or receives different frequencies according to different angles in bandwidth in the extending direction of wave-guide so that it can accomplish frequency scanning. Scanning range is about 6.1°. The gain of main lobe is higher and the difference between the main lobe level and minor lobe level at every frequency point is larger. The antenna has advantages of compact structure, small volume, light weight, low cost, faster scanning, which provides a certain application value for the terahertz scanning imaging technology..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 711004 (2015)
Experimental Research on Pseudo-Thermal Light Ghost Imaging with Random Phase Plate Based on Variable Motion Trail
Wu Nan, Gong Wenlin, and Han Shensheng
In order to ensure the independence of every sampling, ghost imaging system with repeatable pseudothermal light based on random phase plate moves one laser spot in each sampling to produce pseudo-thermal light. By using rotating motor and linear motor to control motion trail of random phase plate, an experimental platfIn order to ensure the independence of every sampling, ghost imaging system with repeatable pseudothermal light based on random phase plate moves one laser spot in each sampling to produce pseudo-thermal light. By using rotating motor and linear motor to control motion trail of random phase plate, an experimental platform is established. Based on differential ghost imaging linear reconstruction algorithm and nonlinear sparsity constraints reconstruction algorithm, the influence of different offset value Δx of the random phase plate on the quality of ghost imaging is studied researched. The results of the simulation and experimental results demonstrate that in the case of the same compression ratio, when Δx is no more than the speckle size Δxs , the imaging quality enhances with increasing Δx , and when Δx is larger than Δxs , the imaging quality almost does not change with increasing Δx. Besides, in the case of the same sampling, the imaging quality by using nonlinear sparsity constraints reconstruction algorithm is better than that by using differential ghost imaging linear reconstruction algorithm..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 711005 (2015)
Error Analysis of Spot Diagram’s Mean Radius Measured with CCD Sensor and Choice of the Optimal Threshold
Zhou Longfeng, Zhang Ang, Zhang Junbo, and Xian Hao
In the process of error correction based on reflecting telescope system, definition function of spot target is usually used as performance metric of imaging quality. The definition function will reach extremum by using optimization algorithm to correct parameter error. Mean radius as definition function of spot diagramIn the process of error correction based on reflecting telescope system, definition function of spot target is usually used as performance metric of imaging quality. The definition function will reach extremum by using optimization algorithm to correct parameter error. Mean radius as definition function of spot diagram is widely used for its large- scale and good dynamic property in correction. While the value of mean radius of calculation is different from the value of theory because of the noise of detector, thus the correction process is affected. The calculation error of mean radius because of noise and the influence of threshold is analyzed through theory and simulation.The result indicates that there exists an optimal threshold to make the error minimum. A fitting formula is proposed by the simulating optimal thresholds in different noise intensities.The formula can accurately calculate optimal thresholds..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 711006 (2015)
Research on the Effects of Forward Scattering Angle to Polarization Imaging Contrast
Zhan Juntong, Fu Qiang, Zhang Su, Duan Jin, Zhang Yalin, An Yan, Liu Xianzhu, and Jiang Huilin
For analyze the impact of the forward scattering angle to polarization imaging, starting from the contrast ratio of the polarization image, the target is irradiated by horizontal polarization and - 45° linear polarization respectively with 532 nm wavelength in different polarization states of the linearly polarizeFor analyze the impact of the forward scattering angle to polarization imaging, starting from the contrast ratio of the polarization image, the target is irradiated by horizontal polarization and - 45° linear polarization respectively with 532 nm wavelength in different polarization states of the linearly polarized light, the polarization image contrast of them are calculated. The results show that the polarization image contrast is raised by the increasing of forward scattering angle and the horizontal linear polarization image contrast is lower than that of -45° linear polarization. The experimental results can provide technical support for the subsequent work on polarization imaging detection..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 711007 (2015)
Instrumentation, Measurement and Metrology
MTF Measurement Method Based on Slanted-Edge Image Simulated by Normal Distribution
Yuan Hangfei, Guo Yongfei, Si Guoliang, Li Yunfei, and Qu Lixin
The modulation transfer function (MTF) is one of the key indicators to evaluate the signal transmission frequency characteristics of an optical imaging system, and the slanted-edge method is one of the important MTF measurement methods. To solve the problem that the traditional slanted-edge measurement method is not roThe modulation transfer function (MTF) is one of the key indicators to evaluate the signal transmission frequency characteristics of an optical imaging system, and the slanted-edge method is one of the important MTF measurement methods. To solve the problem that the traditional slanted-edge measurement method is not robust against noise, a new MTF measurement method based on the normal distribution fitting and median point estimate is proposed. A modified method that estimates the edge angle by fitting a two-dimensional function to the image data based on the normal distribution is proposed, the optimum slope angle and edge-spread curve of the actual image are calculated by using the method of looking up median point to the fitted image, and the edge-spead function (ESF) is achieved by using the Fermi function. The experimental result shows that the precision of the edge angle of the modified method is improved obviously when the noise of the actual image is relatively seriously, and the precision of the value of the MTF is also increased..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 712001 (2015)
Design of High-Precision Phase Computer-Generated-Hologram
Zhu Deyan, and Zhang Xuejun
To solve the high precision of testing of aspheric surface or even free-form surface, the line binary grating theory is used, gave the influence result of each errors of the computer generated hologram (CGH), based on an 846 mm×630 mm free-form surface, the CGH to test the surface is designed and manufactured. TheTo solve the high precision of testing of aspheric surface or even free-form surface, the line binary grating theory is used, gave the influence result of each errors of the computer generated hologram (CGH), based on an 846 mm×630 mm free-form surface, the CGH to test the surface is designed and manufactured. The result shows that when design CGH to test surface, first separate the diffraction order, change the distance between the focus of the interferometer to CGH to decrease the pattern distortion; calibrate the substrate errors; at last choose duty-cycle to 0.5, etching depth to 0.3λ to decrease duty-cycle errors，phase function errors and amplitude errors when encoding..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 712002 (2015)
A Camera Calibration Method for Large Field Camera Pointing at Sky on Sway Platform
Guan Banglei, Sun Xiangyi, Shang Yang, and Yu Qifeng
A camera parameters field calibration method using dynamic control points created by unmanned aerial vehicle (UAV) is presented for large field camera difficult to calibrate air photograph on sway platform. The camera continuously shoots images when UAV is flying at the field of view, the position of UAV is measured byA camera parameters field calibration method using dynamic control points created by unmanned aerial vehicle (UAV) is presented for large field camera difficult to calibrate air photograph on sway platform. The camera continuously shoots images when UAV is flying at the field of view, the position of UAV is measured by the designed system fixed on the sway platform, thus all the UAV′ s positions in the entire flight are used as control points for camera calibration, and the control points are easily distributed in space or in the calibration image rationally, the camera parameters are solved accurately by using the sufficient number of control points and images. The proposed method overcomes the contradiction that the condition of traditional camera calibration methods often cannot be constructed in some field experiments. The proposed camera calibration method requires low field experimental conditions that demand a minimum of coordinates of two reference points and azimuth camera optical center in the reference coordinate system on sway platform. The proposed method is successfully used in applications, such as calibrating the camera in the berthed ship..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 712003 (2015)
Measuring Fine Particle Size with RGB Three Wavelength Bands Light Extinction Method
Li Shizhu, Cai Xiaoshu, Gao Wei, and Liu Hao
A camera based RGB three wavelength bands light extinction for fine particle size measurement is proposed. When a particle system is illuminated by a parallel white light, the transmitted light of different wavelengths can be analyzed by the light extinction theory to calculate the particle size. Using a color camera aA camera based RGB three wavelength bands light extinction for fine particle size measurement is proposed. When a particle system is illuminated by a parallel white light, the transmitted light of different wavelengths can be analyzed by the light extinction theory to calculate the particle size. Using a color camera as a detector, the transmitted light is recorded in RGB three wavelength bands. The recorded signal is related to the camera′ s RGB response curve, light source spectrum characterization, particle size and concentration. Analyzing the RGB three wavelength bands signal with the light extinction theory, the particle size distribution can be determined. The simulations and experiments are carried out. And the results show the feasibility of this method. This approach combining image measurement with the light extinction method, enable the camera based particle size measurement ranged from sub micrometer to hundreds micrometers..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 712004 (2015)
Displacement Measuring Method Based on Astigmatism Effect of Crossed Cylindrical Lenses
Han Qing, Wang Jian, Li Can, Liu Ying, and Sun Qiang
Higher precision, non- destructive and handy are necessary to the displacement measurement. Astigmatism effect in orthogonal cylindrical lenses is utilized to measure object displacement. In paraxial approximation, matrix methods for Gaussian ray model are used to trace analysis. In addition, Zemax is adopted to simulaHigher precision, non- destructive and handy are necessary to the displacement measurement. Astigmatism effect in orthogonal cylindrical lenses is utilized to measure object displacement. In paraxial approximation, matrix methods for Gaussian ray model are used to trace analysis. In addition, Zemax is adopted to simulate the behavior of the model. Then, the displacement measuring system is set up.At the same time,measuring range and resolution of the system are discussed briefly. The result of the experiment indicates an applicable measuring range of 5.6 μm with a highly accuracy of 200 nm for displacement measurement. The technique provides a new noncontract, highly accuracy method for displacement measurement..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 712005 (2015)
Lasers and Laser Optics
Matric Analysis and Experimental Design of Offner Stretcher
Guo Xiaoyang, Leng Yuxin, Xu Yi, Li Wenkai, Lu Xiaoming, Peng Yujie, Lu Jun, Wang Cheng, and Li Ruxin
Effective grating pair distance of Offner triplet stretcher is obtained by matric optics. Pulse duration after stretcher calculated formula and the elements’size analytic expressions are obtained. A generalized solution designing a practical Offner stretcher and an example are provided. The analytic results are in agreEffective grating pair distance of Offner triplet stretcher is obtained by matric optics. Pulse duration after stretcher calculated formula and the elements’size analytic expressions are obtained. A generalized solution designing a practical Offner stretcher and an example are provided. The analytic results are in agreement with the ray tracing results..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 714001 (2015)
Chaos Complexity of Erbium-Doped Chaotic Fiber Ring Laser
Yang Huanhuan, Yang Lingzhen, Zhang Jun, and Wang Juanfen
The complexity of the erbium doped fiber ring lasers is experimentally investigated based on the autocorrelation function and permutation entropy function. By controlling the loss in the ring cavity, the different chaotic complexity is analyzed in detail. The experimental results show that the intra-cavity loss has greThe complexity of the erbium doped fiber ring lasers is experimentally investigated based on the autocorrelation function and permutation entropy function. By controlling the loss in the ring cavity, the different chaotic complexity is analyzed in detail. The experimental results show that the intra-cavity loss has great effect on the chaotic complexity of fiber laser. With increase of the loss, the permutation entropy complexity increases gradually and the time- delay signature shown in the autocorrelation curves can also be suppressed. By controlling the intra-cavity loss, the time-delay signature of chaos is completely hidden and its permutation entropy complexity reaches a maximum, which can effectively improve the security of chaotic secure communications and the measurement precision of chaotic sensing or ranging..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 714002 (2015)
Generation and Synchronization of Chaos in Single-Ring Erbium-Doped Fiber Lasers Based on Delay Phase-Shift Feedback Control
Zhang Xu, Feng Yuling, and Yao Zhihai
The generation of chaos in single-ring erbium-doped fiber laser (SREDFL) is investigated by using the delay phase-shift feedback. Chaos generation is realized in the SREDFL by properly adjusting the parameters such as the feedback coefficient, the phase-shift, and the delay time. The routes of chaos generation and the The generation of chaos in single-ring erbium-doped fiber laser (SREDFL) is investigated by using the delay phase-shift feedback. Chaos generation is realized in the SREDFL by properly adjusting the parameters such as the feedback coefficient, the phase-shift, and the delay time. The routes of chaos generation and the parameter ranges of the chaotic states are given. Moreover the chaotic synchronization of two SREDFLs is investigated by using the method of chaotic signal driving. The results show that no matter the original driven systems are in chaotic state or periodic state, the chaotic synchronization can be completed by appropriately adjusting the driving intensity. Furthermore, the chaos synchronization quality is analyzed by using the correlation coefficient..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 714003 (2015)
Machine Vision
An Efficient Road Detection Algorithm Based on Parallel Edges
Wang Wenfeng, Ding Weili, Li Yong, and Yang Shujun
In order to improve the accuracy and efficiency of intelligent venicle road extraction, a road detection algorithm based on parallel edge features is proposed. A new fast rough segmentation algorithm for road area image based on edge connection is proposed. Edges points local linear detection and direction are coded, aIn order to improve the accuracy and efficiency of intelligent venicle road extraction, a road detection algorithm based on parallel edge features is proposed. A new fast rough segmentation algorithm for road area image based on edge connection is proposed. Edges points local linear detection and direction are coded, and the vertical lines are detected to estimate the most likely road region. The parallel edges in the most likely road region are extracted based on the similarity degree of local orientation, and three efficient criterions are presented to extract the road region. Experimental results show that the proposed algorithm is suitable for various road images, which can accurately detect the road regions of straight and curved roads at a fast time. The speed and accuracy of the proposed algorithm improves largely..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 715001 (2015)
High Resolution Light Field Depth Reconstruction Algorithm Based on Priori Likelihood
Ding Weili, Ma Pengcheng, Lu Ming, and Huang Xiangsheng
In order to solve the problem that traditional two-frame and multi-view stereo matching have a poor effect and robustness in dealing with occlusion and low texture regions. A depth reconstruction algorithm based on epipolar plane image (EPI) is proposed to reconstruct complicated and fine scenes deeply. According to thIn order to solve the problem that traditional two-frame and multi-view stereo matching have a poor effect and robustness in dealing with occlusion and low texture regions. A depth reconstruction algorithm based on epipolar plane image (EPI) is proposed to reconstruct complicated and fine scenes deeply. According to the special linear structure of EPI, a cross-detect model is proposed to detect the outlines of EPI, whose depth is computed by combining the exponent distance function and distance weight coefficient. The contour depth is used as a priori to the inner flat regions, and the priori likelihood is integrated into an energy function. The contour depth is propagated to the whole depth map by minimizing the energy function. The proposed algorithm is local, so it not only preserves the exact contour edge depth but also assures the smoothness of low texture regions. The test result shows that the proposed algorithm is superior to the primary in term of reconstruction speed and quality..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 715002 (2015)
Space Point Positioning Based on Optimization of Fisheye Lens Imaging Model
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Due to the big position error and strong limitations by using high odd polynomial method and optical refraction model, an optimization of fisheye lens imaging position algorithm is proposed. A new distortion model is derived according to the decentering distortion of the lens and optimized imaging model is established Due to the big position error and strong limitations by using high odd polynomial method and optical refraction model, an optimization of fisheye lens imaging position algorithm is proposed. A new distortion model is derived according to the decentering distortion of the lens and optimized imaging model is established based on the distortion model and optical refraction model. After calibrating the imaging model parameters, a back projection model is derived and then three dimensional point coordinates are obtained. Space targets are precisely positioned. Experimental results show that the proposed algorithm has far less relative positioning error than the method which using high odd polynomial and optical refraction when the measured object respectively in fisheye image center and edge areas. Compared with previous method, the image distortion of proposed algorithm obviously has less influence on measurement precision and it effectively improves the positioning accuracy..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 715003 (2015)
Small Target Detection Based on Visual Saliency Improved by Spatial Distance
Yang Linna, An Wei, Lin Zaiping, and Li Andong
In human visual system (HVS), is the contrast value occupies the most important part rather than the brightness. The existing infrared small target detection algorithm based on HVS can get a higher signal to noise ratio and detection rate, but it also has shortcomings of higher false alarm rate and easily effected by nIn human visual system (HVS), is the contrast value occupies the most important part rather than the brightness. The existing infrared small target detection algorithm based on HVS can get a higher signal to noise ratio and detection rate, but it also has shortcomings of higher false alarm rate and easily effected by noise. Considering those shortcomings, An infrared small target detection algorithm based on visual saliency improved by spatial distance is proposed. The gray value of target is weighted by the ratio of the target pixel block and its surrounding blocks, and a saliency map is got. Spatial distance is one of the most important factors in visual attention mechanism and is used in the calculation of the weighted sum of the surrounding blocks. Smaller weight value is distributed to fruther distance according to the weighted space distance. Experimental results show that the proposed algorithm can not only get a lower false alarm rate, but also has robustness for noise..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 715004 (2015)
Medical Optics and Biotechnology
Fluorescence Molecular Tomography Based on Nonconvex Sparse Regularization
Guo Hongbo, He Xiaowei, Hou Yuqing, Dong Fang, and Zhang Shuling
To improve the accuracy of fluorescence molecular tomography (FMT), non-convex LP (0<P<1) regularization is introduced into 3D reconstruction. By transforming the non-convex optimization problem into a series of weighted L1 regularization problems, an iterative reconstruction scheme based on the weighted homotopyTo improve the accuracy of fluorescence molecular tomography (FMT), non-convex LP (0
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 717001 (2015)
Nonlinear Optics
Transmission Control of Line Optical Rogue Waves in Two-Dimension Graded-Index Waveguides
Hu Wencheng, Zhang Jiefang, Huang Wenhua, and Lu Zhiming
Optic pulse propagation in inhomogeneous nonlinear waveguides can be described by nonlinear Schrodinger equation with (2+1) dimension variable coefficients. Similarity transformation is used to construct exact optical rogue wave solutions of (2 + 1) dimensional nonlinear Schrodinger equation with varying coefficients. Optic pulse propagation in inhomogeneous nonlinear waveguides can be described by nonlinear Schrodinger equation with (2+1) dimension variable coefficients. Similarity transformation is used to construct exact optical rogue wave solutions of (2 + 1) dimensional nonlinear Schrodinger equation with varying coefficients. Moreover，the dynamic of the first- order optical rogue waves in the optical fiber amplifier is investigated by the nonlinear Schrodinger equation with an external harmonic potential. Manipulating propagate conditions of two- dimensional optical rogue waves are given. In the suitable regulation of parameters, the properties of the optical rogue waves are found, such as amplitude and position, which are controllable in the nonlinear media. In the controllable parameters, the propagation behaviour of the controllable light waves in the nonlinear media are discussed, including delayed excitation, annihilation and maintaining. These results give edification in theory and practical application..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 719001 (2015)
Optical Design and Fabrication
Analysis and Optical Design of Very High Spectral Resolution Imaging Spectrometer of the Atmospheric CO2
Song Wenbao, Jin Yangming, Zhao Zhicheng, Shen Weimin, and Fan Dongdong
For monitoring the emission of CO2 in the global scopes, determining the location of carbon sources and sinks, high precision detection of the column concentration of atmospheric CO2 is needed. First, the principle of remote sensing of the column concentration of atmospheric CO2 is introduced, and the relationship betwFor monitoring the emission of CO2 in the global scopes, determining the location of carbon sources and sinks, high precision detection of the column concentration of atmospheric CO2 is needed. First, the principle of remote sensing of the column concentration of atmospheric CO2 is introduced, and the relationship between detection accuracy, spectral resolution and the required signal to noise ratio (SNR) is analyzed by using the lineby-line radiative transfer model (LBLRTM). Then based on satellite remote sensing requirements, the indexes of the optical system are analyzed. According to the indexes, echelle immersion grating is chosen as light splitting element, the inverse Cassegrain telescope and the off-axis three-mirror anastigmat structure beam splitting system is determined. The optical system of atmospheric CO2 column concentration detection imaging spectrometer with F number 4 and spectral resolving power of 21000 is designed. This optical system consists of a single telescope, a set beam splitting system and three pieces of focal plane array which has small size and good image quality..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 722001 (2015)
New Method for First-Order Structure Design of Continuous Zoom Lens System
Zhai Tingting, and Zhu Jianqiang
The core issue for first- order structure design of mechanical compensated zoom system is to determine the optical power and distance of components. In order to reduce excessive dependence on designing experience, a method is proposed for first- order structure design of continuous zoom lens system. Taking the optical The core issue for first- order structure design of mechanical compensated zoom system is to determine the optical power and distance of components. In order to reduce excessive dependence on designing experience, a method is proposed for first- order structure design of continuous zoom lens system. Taking the optical power and distance of components as optimization variables, the motion equations are generated at different zoom positions. Regarding the image plane stability, total length of system and Petzval field curve as the evaluation function, the optimal solution is searched in multi- dimensional constraint space by particle swarm algorithm. In order to verify the feasibility of the proposed method, a first-order structure is optimized with the focal length ranging from 10 mm to 100 mm. This paper provides a new idea of solving the first-order structure of mechanical compensated zoom system..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 722002 (2015)
Small Distortion Panoramic Annular Lens Design with Q-Type Aspheres
Zhou Xiangdong, and Bai Jian
Implemented Q-type aspheres interface in Zemax by means of user defined surface dynamic link library (DLL), and then design of a panoramic annular lens (PAL) with Q-type aspheres worked in the visible spectrum is presented. The designed PAL’s half field of view (FOV) in vertical plane is 30°～110°, focal lengtImplemented Q-type aspheres interface in Zemax by means of user defined surface dynamic link library (DLL), and then design of a panoramic annular lens (PAL) with Q-type aspheres worked in the visible spectrum is presented. The designed PAL’s half field of view (FOV) in vertical plane is 30°～110°, focal length is -1.25 mm, F Number is about 5 with a total length of 28.7 mm, which includes six spherical lenses and one lens with two Qtype aspheres. The performances of the designed optics are also analyzed. F-Theta distortions at the whole fields are less than 1%, and modulation transfer function (MTF) values are greater than 0.5 at the Nyquist spatial frequency of 83 lp/mm that is approaching to the diffraction limit. For validating Q-type aspheres’s superiority in PAL design, an even aspherical PAL with the same parameters has been designed to compare with the Q-type ones. The results show that, under the same computing platform, Q-type aspheric polynomial coefficients have 3~6 more significant digits than the corresponding even aspheric ones which can effectively reduce the computer truncated error in the optimization process. It’s help to speed up the design progress and enhance the precision of manufacturing and inspection of aspheric optical components..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 722003 (2015)
Optical Devices
Fast All-Optical Switch Based on Nonlinear Polarization Rotation in Cascaded Semiconductor Optical Amplifiers
Zhu Zhe, Sheng Xinzhi, Mao Yaya, Wu Chongqing, Wang Ran, and Wang Ying
The principle states of polarization (PSP) alignment in multilevel cascaded semiconductor optical amplifiers (SOA) system are studied based on the relationship between their PSP alignment and Poincare Sphere′ s correlation. Scheme of the all- optical switch is proposed based on nonlinear polarization rotation (NPR) in The principle states of polarization (PSP) alignment in multilevel cascaded semiconductor optical amplifiers (SOA) system are studied based on the relationship between their PSP alignment and Poincare Sphere′ s correlation. Scheme of the all- optical switch is proposed based on nonlinear polarization rotation (NPR) in multilevel cascaded SOAs. An all- optical switch is demonstrated based on NPR in two cascaded SOAs. A light signal of 50 μW is all- optically switched by a square wave control light of 6 mW, and the switching speed is 200 ps. The all- optical switch′ s wavelength band is from 1510 nm to 1570 nm, and its insertion loss is 3.62 dB and power consumption is 12 mW. The all- optical switch has advantages like high switching speed, low insertion loss and power consumption, and good compatibility with optical fiber communication system and will effectively promote the technology development in all-optical switch field and all-optical network field, as well as optical computing field and all-optical signal processing field..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 723001 (2015)
Physical Optics
Study on Properties of Speckle Field Formed by Laguerre-Gaussian Beam Illumination
Li Xinzhong, Tian Xiaomin, Wang Hui, Tang Jie, Wang Yishan, Nie Zhaogang, Li Hehe, and Wang Jingge
The properties of speckle field is studied when Laguerre-Gaussian (LG) beams illuminate a ground glass plate. The LG vortex beams are generated by a spatial light modulator combing with computer-generated hologram. The relation of speckle size and azimuthal and radial indices and the bright region of the LG beams are aThe properties of speckle field is studied when Laguerre-Gaussian (LG) beams illuminate a ground glass plate. The LG vortex beams are generated by a spatial light modulator combing with computer-generated hologram. The relation of speckle size and azimuthal and radial indices and the bright region of the LG beams are analyzed experimentally. Experimental results show that the speckle size decreases linearly with the azimuthal index increasing for certain radial index. Similarly, the speckle size also decreases with the radial index increasing for certain azimuthal index. Moreover, the speckle size is proportional to the negative factor of illuminating area of the LG beam. Further, the negative factor is gradual close to the results of Gaussian beam illuminating with the increasing radial index..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 726001 (2015)
Generation and Propagation Characters of Broad Band Radially Polarized Beam
Zhang Lei, and Pu Jixiong
The method of generating broad band radially polarized beam and its propagation are researched. The relationship between generation，propagation characteristics and their coherence, i.e. temporal coherence and spatial coherence is analyzed. The propagation of broad band radially polarized beam is numerically simulated. The method of generating broad band radially polarized beam and its propagation are researched. The relationship between generation，propagation characteristics and their coherence, i.e. temporal coherence and spatial coherence is analyzed. The propagation of broad band radially polarized beam is numerically simulated. Spatial coherence is changed by the method of modifying the distance of incident beam from xenon lamp. Polarization degree is also examined, and theoretical values agree well with experimental data..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 726002 (2015)
Quantum Optics
An All-Fiber Continuous Variable Quantum Key Distribution Based on Multi-bits Coding of Single Pulse
Chen Yan, Shen Yong, and Zou Hongxin
An all-fiber continuous variable quantum key distribution by implementing discrete-modulated coherent state protocol based on multi-bits coding of single pulse is realized. The system employs a scheme combining polarization and frequency multiplexing. The pulse width of quasi-continuous wave is 200 ns. Each pulse is diAn all-fiber continuous variable quantum key distribution by implementing discrete-modulated coherent state protocol based on multi-bits coding of single pulse is realized. The system employs a scheme combining polarization and frequency multiplexing. The pulse width of quasi-continuous wave is 200 ns. Each pulse is divided into four equal parts in time domain. In order to increase the secure key rate, the two quadrature components of each part are encoded with random number. At a repetition rate of 1MHz, the system achieves a final secure key rate of 32.8kb/s over a distance of 25km of optical fiber..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 727001 (2015)
Quantum Properties of Two-Photon Jaynes-Cummings Model without Rotating Wave Approximation
Cong Honglu, Ren Xuezao, and Liao Xu
Quantum properties of a two photon Jaynes-Cummings model (JCM) interacting with a single mode coherent light field is calculated mechanically without rotating wave approximation. The evolution properties of the two-photon JCM and JCM quantum entanglement and the atomic population inversion are contrasted. The effects oQuantum properties of a two photon Jaynes-Cummings model (JCM) interacting with a single mode coherent light field is calculated mechanically without rotating wave approximation. The evolution properties of the two-photon JCM and JCM quantum entanglement and the atomic population inversion are contrasted. The effects of the mean photon number, the atom- field coupling coefficient and the detuning on the quantum entanglement and the atomic population inversion are studied. The numerical results indicate that, with the increase of the atom-field coupling coefficient, the period of the entanglement evolution disappear gradually, and it takes longer time for the mean entanglement to reach the maximum value with increasing of the mean photon number. The little indentation oscillation appears in the evolution curves of quantum entanglement and the collapse regime of the atomic population inversion, which is caused by virtual photon effect, weather increasing of the atom-field coupling coefficient or the mean photon number and the detuning..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 727002 (2015)
Quantum Properties of State via Operation of Light Field Combination Operator on Chaotic Field
Lu Daoming
Light field combination operator excited chaotic field is constructed by operation of light field combination operator on chaotic field. Its squeezing, antibunching effect, statistical property and negativity of Wigner function are analysed by calculating two orthogonal components of the light field fluctuations, seconLight field combination operator excited chaotic field is constructed by operation of light field combination operator on chaotic field. Its squeezing, antibunching effect, statistical property and negativity of Wigner function are analysed by calculating two orthogonal components of the light field fluctuations, secondorder correlation function, Mandel Q parameters and Wigner function, respectively. The influences of superposition coefficient of operators and the average photon number of the field on quantum properties are discussed. Results show that the nonclassical property of the field is weakened with the increase of average photon number of the field. On the other hand, its antibunching effect and sub- poissonian statistical property are strengthened as the ratio of photon addition operator in superposition operation increases. The result shows that the increase of the ratio of photon addition operator in superposition operation can help strengthen antibunching effect and sub-poissonian distribution property..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 727003 (2015)
Avalanche Luminescence Crosstalk between Avalanche Photodiodes
Gao Yanlei, Lu Xiaogang, Bai Jinhai, Wang Meng, Wu Ling-an, Wang Ruquan, Pang Zhaoguang, Yang Shiping, Fu Panming, and Zuo Zhanchun
Avalanche photodiode (APD) has a wide range of applications for time- correlated single- photon counting in quantum secure communication, quantum cryptography, and other quantum optics fields. However, during APD operation, incident photons in the absorption layer create carriers, which then multiply exsponentially. AsAvalanche photodiode (APD) has a wide range of applications for time- correlated single- photon counting in quantum secure communication, quantum cryptography, and other quantum optics fields. However, during APD operation, incident photons in the absorption layer create carriers, which then multiply exsponentially. As each carrier goes through the P-N junction node there is a certain probability that it will cause the emission of another photon. Under certain conditions this newly emitted photon can generate crosstalk in the other avalanche photodiode, thus affecting the time-correlated single-photon counting results when detecting single photons in the Geiger mode. Through experimentally reproducing the phenomenon of relatively high contrast crosstalk interference we analyze the factors influencing the crosstalk peak, including peak spacing and shape. A scheme using optical isolation is proposed to avoid the crosstalk, and its feasibility is verified experimentally..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 727004 (2015)
Remote Sensing and Sensors
Application of Smoothness Prior Aproach for Coherent Doppler Wind Lidar
Li Lu, Guo Pan, Zhang Yinchao, Chen Siying, and Chen He
The periodogram maximum estimator is usually employed in coherent Doppler wind Lidar. However, the estimates are biased in the far-field with low signal-to-noise region, and the wind speed errors will increase. The baseline- drift of the range gate power spectra is one of the error items, which biases the benchmark of The periodogram maximum estimator is usually employed in coherent Doppler wind Lidar. However, the estimates are biased in the far-field with low signal-to-noise region, and the wind speed errors will increase. The baseline- drift of the range gate power spectra is one of the error items, which biases the benchmark of spectral peak distribution and interferences the peak- frequency detection. In order to correct the drifting, the smoothness prior approach based on the regularization penalized least squares is introduced to estimate the spectral baseline. In the atmospheric wind speed measurements, the result shows that the proposed approach can remove the drift baseline effectively, improve the wind speed estimation precision in far-fields significantly and increase the detection range of the wind Lidar ultimately..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 728001 (2015)
A Comprehensive Evaluation Method Based on Analytic Hierarchy Process for CCD Pixel Subdivision Algorithms
Chen Jiawei, Zhang Yuanfei, Zhang Yu, and Xie Zongwu
The accuracy of laser range finder based on CCD can be effectively improved by pixel subdivision. There are mant pixel subdivision algorithms, and each has advantages and specific application. However, according to the specific range finder, there is no effective mean to evaluate which algorithm is better comprehensiveThe accuracy of laser range finder based on CCD can be effectively improved by pixel subdivision. There are mant pixel subdivision algorithms, and each has advantages and specific application. However, according to the specific range finder, there is no effective mean to evaluate which algorithm is better comprehensively. Hence, a comprehensive evaluation method is proposed, which is based on analytic hierarchy process (AHP) and is used to evaluate the pixel subdivision algorithms. This method is based on actual positioning precision, variance and range of the pixel subdivision algorithms in the proximal, the middle and the distal of measuring range of the laser range finder. And it constructs the comprehensive evaluation model by AHP. According to the method, the applicability of the dichotomy, weighted centroid, weighted polynomial interpolation and center from the proportion algorithm for the specific range finder is analyzed by experiment. The experimental results show that the method can be used to obtain the optimal pixel subdivision algorithm for specific range sensor effectively..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 728002 (2015)
On-Orbit Calibration and Evaluation of GF-2 Satellite Based on Wide Dynamic Ground Target
Han Qijin, Ma Lingling, Liu Li, Zhang Xuewen, Fu Qiaoyan, Pan Zhiqiang, and Wang Aichun
To validate the radiometric performance changing of GF-2 satellite, and obtain reliable on-orbit calibration coefficients of GF-2 sensors, an in-situ calibration methodology based on wide dynamic ground target is presented. Based on Dunhuang Gobi site, a test site including high, middle, and low reflective characteristTo validate the radiometric performance changing of GF-2 satellite, and obtain reliable on-orbit calibration coefficients of GF-2 sensors, an in-situ calibration methodology based on wide dynamic ground target is presented. Based on Dunhuang Gobi site, a test site including high, middle, and low reflective characteristics is re-selected and established. After that, the first on-orbit calibration for GF-2 is performed using the reflectance-based method and field measurement campaign. At last, the calibration coefficients changes and influence by comparing with prelaunch laboratory calibration results is discussed. The results indicate that: 1) the system offset of GF-2 itself is close to zero and relatively stable, while the radiometric responsivity has changed; 2) the calibration coefficients by using multi-site calibration method can better characterize on-orbit performance of GF-2 compared to the prelaunch lab calibration; the new calibration coefficients can be used for quantitative products retrieval and systems performance evaluation..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 728003 (2015)
A Cloud-Top Height Detection Method for Autonomous Planning of Satellites
Kong Xianghai, Chen Yueting, Li Qi, Feng Huajun, and Xu Zhihai
Autonomous planning of high-resolution optical earth-observing agile satellites requires on-orbit clouds detection over observation zones ahead, in order to reschedule the time window to enhance the operational effectiveness of satellites. Cloud heights are essential information, a cloud heights detection method for auAutonomous planning of high-resolution optical earth-observing agile satellites requires on-orbit clouds detection over observation zones ahead, in order to reschedule the time window to enhance the operational effectiveness of satellites. Cloud heights are essential information, a cloud heights detection method for autonomous planning of satellites is proposed. On the basis of the difference in matching relationship between cloud and ground with different points remote sensing images, projecting deviation of cloud to ground is computed on the reference of ground and then cloud- top height is calculated by geometric relation. The simulation experimental result demonstrates that the disparity of cloud-top heights between detected and actual is less than 1 pixel and the method performs stably even rotation and affine transformation among images. Error analysis shows the trend of relative error along with different imaging angles. The experimental results of muti-angle imaging spectroradiometer images suggest that the proposed method has convincing performance over the real appilication..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 728004 (2015)
Reviews
Research on Rotating Paraboloid Based Surface in Space Laser Communication Network
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Rotating paraboloid mirror mosaic structure antenna has important applications in the multi- point space laser communication. Different rotating paraboloid base surfaces result in different communication ranges.The relationship between the parabola coefficient p and communication range θ with different effective apertuRotating paraboloid mirror mosaic structure antenna has important applications in the multi- point space laser communication. Different rotating paraboloid base surfaces result in different communication ranges.The relationship between the parabola coefficient p and communication range θ with different effective apertures is discussed rationally. The results show that the maximum communication angle can achieve 118.7377° ，where the parabola coefficient p is 28 in the reasonable range. However, because of restrictions coming from the following system, the surface need to be a reasonable choice that the parabola coefficient p is 50, and the maximum communication angle is 109.8084°..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 706003 (2015)
Spectroscopy
Research on Fluorescence Enhancement Effect of Silver Nanoparticles on Zinc Porphyrin
Wang Jingjing, Liu Ying, Wu Ying, and Sun Song
Adult blood with silver nanoparticles is radiated by laser with wavelength of 407 nm, and the effect of colloidal silver nanoparticles on the fluorescence performance of zinc porphyrin (ZPP) in blood has been investigated. It has been found that colloidal silver nanoparticles can enhance fluorescence intensity of ZPP iAdult blood with silver nanoparticles is radiated by laser with wavelength of 407 nm, and the effect of colloidal silver nanoparticles on the fluorescence performance of zinc porphyrin (ZPP) in blood has been investigated. It has been found that colloidal silver nanoparticles can enhance fluorescence intensity of ZPP in low concentration human blood significantly, the highest enhancement ratio is about 5.2. Moreover, with the increase in silver colloid amount, the fluorescence enhancement efficiency increases firstly and then decreases. Theoretical analysis indicates that when the distance between ZPP molecules and silver nanoparticles in the solution meets fluorescence enhancement condition, the intensity of ZPP fluorescence can be improved. However, after adding extra silver particles, the distance between molecules will decrease, which is detrimental to the enhancement effect. The research shows that silver nanoparticles can enhance the fluorescence intensity of ZPP in low concentration human blood, which is important for the improvement of ZPP detection sensitivity and accuracy..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 7, 730001 (2015)
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