Journals >Acta Photonica Sinica
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2010
Volume: 39 Issue 6
36 Article(s)
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Research Article
Design Diffractive Optical Elements for Beam Shaping with Hybrid Algorithm
PANG Hui, YING Chao-fu, FAN Chang-jiang, LIN Pei-qiu, and WU Hao-wei
A novel algorithm,which combines a genetic algorithm with an iterative quantization fourier transform algorithm and hill-climbing algorithm, is presented to design diffractive optical elements for beam shaping.This hybrid algorithm firstly takes the genetic algorithm which combines the iterative soft quantization fouriA novel algorithm,which combines a genetic algorithm with an iterative quantization fourier transform algorithm and hill-climbing algorithm, is presented to design diffractive optical elements for beam shaping.This hybrid algorithm firstly takes the genetic algorithm which combines the iterative soft quantization fourier transform algorithm to obtain a solution.Secondly,the hill-climbing algorithm is applied to search the local best solution around the solution derived firstly.It can acquire good efficiency and uniformity with only a small quantity of iterative number. Simulation result shows that the hybrid algorithm is effective and robust.Compared with other algorithms,this hybrid algorithm can greatly improve the effect of the beam shaping,especially the place where the uniformity is important..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 977 (2010)
The Theory and Design of the Rocket-borne Two Booms Electric Field Instrument
MAN Feng, LIU Bo, JIANG Xiu-jie, LUO Fu-shan, and YU Shi-qiang
Based on the analysis of detection theory of two booms electric field instrument,the detailed design of the electric field instrument boarded on sounding rocket which is used in Meridian Project is presented.In order to reduce asymmetries and inconsistencies of the probe,aluminous spherical probe is adopted.The graphitBased on the analysis of detection theory of two booms electric field instrument,the detailed design of the electric field instrument boarded on sounding rocket which is used in Meridian Project is presented.In order to reduce asymmetries and inconsistencies of the probe,aluminous spherical probe is adopted.The graphite coating is chosen to reduce the surface non-uniformity,and the particular shape design is used to eliminate the shadow effect of the boom.In order to improve the system dynamic range,four frequency ranges is selected,providing a set of analog signals subsequently directed to the data digitization and processing unit.Finally,several error considerations and the test results of system performance are presented.The bandwidth of this electric field instrument is 0～5MHz.The DC detection range is 0.1mV/m～±1V/m and the AC detection range is 10μV/m～50mV/m.The two-dimensional spatial electric field with intensity of 0～±1V/m can be measured..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 982 (2010)
Design of Sub-wavelength Grating with Triangle Carve for Separating Harmonic Waves
WANG Fang, SU Jing-qin, LIU Lan-qin, WANG Fang, WANG Wen-yi, and MO Lei
A new harmonic waves separation technological scheme is proposed based on sub-wavelength grating technology.Then,the merit function is defined to estimate the performance of harmonic waves separation.Grating with triangle carve parameters are design on the basis of vector diffraction theory,of which affecting the meritA new harmonic waves separation technological scheme is proposed based on sub-wavelength grating technology.Then,the merit function is defined to estimate the performance of harmonic waves separation.Grating with triangle carve parameters are design on the basis of vector diffraction theory,of which affecting the merit function are analyzed in details.At last,the grating design methods for harmonic waves separation are proposed..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 988 (2010)
Optical System Design of Light-Small CCD Camera
LI Xu-yang, LI Ying-cai, MA Zhen, and YI Hong-wei
With the development of space technology,small satellite will be widely applied.The paper design a catadioptric system base on Ritchey-Chretion system which including three sphere correction lens.The system has a focal length of 1000,F number of 5,and spectrum band of 450~900 nm,and the field angle reaches 2.3°.thWith the development of space technology,small satellite will be widely applied.The paper design a catadioptric system base on Ritchey-Chretion system which including three sphere correction lens.The system has a focal length of 1000,F number of 5,and spectrum band of 450~900 nm,and the field angle reaches 2.3°.the result indicates that,MTF reaches 0.47 at 77 lp/mm with 15% central obscure,the quality of image approaches the diffraction limit,and optical system distortion is less than 0.5%.The system with simpler structure,small size and light weight,can be used in light-small satellite..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 994 (2010)
Radiation Evolution Characteristic of Lightning Discharge Channel
Zhang Huiming, Yuan Ping, Yang Shigang, Hao Xiaozhi, and Niu Yongbo
Near-infrared spectra of lightning return strokes are obtained by Slit-less infrared spectrograph in Shandong region.Compared with the visible spectrum of lightning return strokes,the radiation order of lighting plasma is analyzed,and the main radiation mechanism of continuum spectra in the two wavelength range are alsNear-infrared spectra of lightning return strokes are obtained by Slit-less infrared spectrograph in Shandong region.Compared with the visible spectrum of lightning return strokes,the radiation order of lighting plasma is analyzed,and the main radiation mechanism of continuum spectra in the two wavelength range are also discussed.The obtained results show that:the visible spectrum of lightning is mainly radiation from early stages and development of lightning,and the line spectra of ionizing nitrogen and oxygen is the main spectra of the separation spectrum; the near-infrared spectrum is mainly radiation from the latter of the lightning, and the line spectra of neutral nitrogen and oxygen atoms is the main spectra of the separation spectrum; the visible spectral band is mainly from bremsstrahlung contribution and the infrared part of the continuous spectrum is mainly from the recombination radiation; loss of a photon for the free electronic of high-temperature and other energy particle collisions of the lightning plasma is the main course of bremsstrahlung process,there are a lot of free e-collision,the lightning channel gathered in a large number of neutral atoms,molecules,electronics,and with the positively charged ions (including N++,N+,N*,N,O++,O+,O*,O particles,etc.),thus forming a typical plasma channel; atmospheric ions and free electrons of the dissociation process and the positive ions and negative ion radiation process is the direct radiation of the two main ways.It is deduced from the results that the recombination in lightning plasma is the main process for lightning producing O3 and NOX,the sorption and desorption of oxygen during the recombination may be the main reason for increased lines of oxygen atom in near-infrared spectra,and also for relative strength of OI 777.4 nm that is larger than normal..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue 6, 998 (2010)
Target Segmentation for Hyperspectral Imagery Based on FastICA
NIAN Yong-jian, ZHANG Zhi, WANG Li-bao, and WAN Jian-wei
Oriented the application background of target recognition and classification for hyperspectral imagery,a new target segmentation method for hyperspectral imagery based on fast independent component analysis (FastICA) is proposed.The concept of virtual dimensionality was introduced to determine the number of target endmOriented the application background of target recognition and classification for hyperspectral imagery,a new target segmentation method for hyperspectral imagery based on fast independent component analysis (FastICA) is proposed.The concept of virtual dimensionality was introduced to determine the number of target endmembers.The mixing matrix of FastICA was initialized by anomaly endmembers,which were extracted from hyperspectral imagery by using unsupervised orthogonal subspace projection.Minimum noise fraction was employed for dimensionality reduction of original data volumes,and FastICA transform was performed on the selected principal components with high signal-noise ratio (SNR) to generate independent components.Finally,constant false alarm rate (CFAR) detection was performed on each IC,which was followed by morphologic filtering.Experimental results on AVIRIS data show that the proposed algorithm can give better target detection performance,as well as better target segmentation..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 1003 (2010)
Computerized Tomography Technique Based on Differential Optical Absorption Spectroscopy
LI Chun-fang
A new computerized tomography (CT) technique based on differential optical absorption spectroscopy for the measurement of concentration field is proposed.A typical CT diagnoses system is designed，which consists of three parts: the lamp-house and its control system,the optical scanning measurement system and the data coA new computerized tomography (CT) technique based on differential optical absorption spectroscopy for the measurement of concentration field is proposed.A typical CT diagnoses system is designed，which consists of three parts: the lamp-house and its control system,the optical scanning measurement system and the data collecting and processing system,and numerical simulations are made.The results show that the projection data are obtained at only four viewing directions from range 0° to 180°,the maximum error of reconstruction image is less than 5％，and the average error is less than 1％..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 1010 (2010)
Materials Classification Based on Spectropolarimetric BRDF Imagery
CHEN Chao, ZHAO Yong-qiang, CHENG Yong-mei, PAN Quan, and LUO Li
A new classify method based on spectropolarimetric BRDF imagery is proposed.The performances of three different selected features in classifyication results under various weather conditions including sunny sky,cloudy,and dark sky are emphasized.The three selected features are material spectral information,spectropolariA new classify method based on spectropolarimetric BRDF imagery is proposed.The performances of three different selected features in classifyication results under various weather conditions including sunny sky,cloudy,and dark sky are emphasized.The three selected features are material spectral information,spectropolarimetric information,and spectropolarimetric BRDF information respectively.Support Vector Machine method is used to classify targets in clutter grass environments,then the classify results based on spectropolarimetric BRDF features are compared with the other two features under the three different weather conditions respectively.The results show that the method based on spectropolarimetric BRDF features performs the best among the three,no matter what the weather conditions are,and its advantage shows most evidently especially in the dark sky.Selecting the spectropolarimetric BRDF information as features in the materials classification will enhance the precision at most time,even in the case when the gray values between backgrounds and targets are very near..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 1026 (2010)
Static Aurora Images Classification Based on Morphological Component Analysis
FU Rong, LI Jie, and GAO Xin-Bo
In order to resolve the problem incurred by low efficient manual classification of tremendous aurora images,an automatic aurora images classification system for huge dataset application is proposed.First,static aurora images are decomposed into texture part and cartoon part with a method called Morphological Component In order to resolve the problem incurred by low efficient manual classification of tremendous aurora images,an automatic aurora images classification system for huge dataset application is proposed.First,static aurora images are decomposed into texture part and cartoon part with a method called Morphological Component Analysis (MCA).Then features extracted from texture part are classified by three classification methods:nearest neighbor (NN),Support Vector Machine (SVM) with RBF kernel and SVM with linear kernel.The experiment results exhibit that the classification accuracy improved by 10%,of which,the SVM with linear kernel is much faster and is therefore suitable for massive data processing..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 1034 (2010)
Microcalcification Diagnosis Based on Dual-Tree Complex Wavelet Transform
YANG Wei, and GAO Xie-ping
A new diagnosis method of microcalcification is applied based on dual-tree complex wavelet transform.A set of texture features are extracted,including the wavelet based features and gray-level histogram based features.Combining the genetic algorithm to optimize the features,the neural network,support vector machine andA new diagnosis method of microcalcification is applied based on dual-tree complex wavelet transform.A set of texture features are extracted,including the wavelet based features and gray-level histogram based features.Combining the genetic algorithm to optimize the features,the neural network,support vector machine and KNN classifier are used to distinguish the benign and malignant microcalcifications.The results of the three different classifiers are analyzed,which show that KNN classifier get the best result and support vector outperformed neural network.Compared with the other two classifiers,KNN classifier is a non-training method which can save much training time.It directly computes the distances between samples,which can reduce the adverse effects caused by inefficient selection of features and minimize the error in classification.The KNN classifier depends on a small quantity of samples when kind deciding,which can solve the problem caused by the imbalance of samples.Compared to traditional wavelet basis,the shift invariance and high regularity of dual-tree complex wavelet make it more helpful for direction selection of image signal,and dual-tree complex wavelet transform will get limited redundancy and less amount of calculation..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 1040 (2010)
An Adaptive Object Tracking Algorithm Combined with Particle Filter and Tensor Subspace
WEN Jing, LI Jie, and GAO Xin-bo
In order to overcome the disadvantage that traditional subspace methods usually lose the two-dimensional information of the objects in image,a novel adaptive object tracking method is proposed.The appearance of the object in tensor subspace is modeled and the object model is updated with online learning method.The objeIn order to overcome the disadvantage that traditional subspace methods usually lose the two-dimensional information of the objects in image,a novel adaptive object tracking method is proposed.The appearance of the object in tensor subspace is modeled and the object model is updated with online learning method.The object is tracked by using particle filter and the prior of affine motion,and the optimal observation is feeded back to the tensor subspace updating.Moreover,DPF is introduced into the subspace updating to reject outliers so as to keep the object subspace precise and compact.The proposed method is able to track targets effectively and robustly under pose variation,short-time occlusion and large lighting and so on in the experiments..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 1047 (2010)
An Optical Method for MSD Addition
LI Mei, HE Hua-can, JIN Yi, and WANG Xian-chao
Ternary optical computer combines light intensity and polarization to denote ternary information.The core component of ternary optical computer is ternary logic optical processor which is designed and completed according to the the decrease-radix design principle (DRDP).This processor can finish all the 19683 dualisticTernary optical computer combines light intensity and polarization to denote ternary information.The core component of ternary optical computer is ternary logic optical processor which is designed and completed according to the the decrease-radix design principle (DRDP).This processor can finish all the 19683 dualistic ternary logic operations.This paper aims at proposing a new method of using ternary logic ternary processor to complete optical addition.To solve the carry-propagation of addition,to use the MSD representation to encode the operand and realize fully parallel carry-free addition.Using this method of combing ternary optical computer and MSD representation together to complete addtion can both take good advantage of the feature of huge band-width and easily finishing dualistic ternary logic operations of ternary optical computer,and make use of the carry-free feature of MSD addition.By experiment the feasibility and correctness are proved and this method is a new idea for optical adder..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 1053 (2010)
Multi-Metric Combined Real-Time Scene Cut Detection Algorithm for Video Coding
MA Yan-zhuo, CHANG Yi-lin, and YANG Hai-tao
A real-time scene cut detection algorithm is proposed which shares the results of motion estimation with the video encoder.To deal with different kinds of scene cuts,two metric functions are introduced based on the statistics of the first and second order difference between the original pictures and their motion compenA real-time scene cut detection algorithm is proposed which shares the results of motion estimation with the video encoder.To deal with different kinds of scene cuts,two metric functions are introduced based on the statistics of the first and second order difference between the original pictures and their motion compensated pictures.The detection thresholds for each metric are adaptively adjusted according to the scenes.The experimental results and analysis show that the recall and precision of the proposed algorithm are generally higher than other tested ones at the cost of little computation time increment..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 1058 (2010)
Investigation of Balanced Detection and Receiver for 1.55 μm Coherent Wind Lidar
GAO Long, WANG Chun-hui, LI Yan-chao, and CONG Hai-fang
Balanced receiver technique for signal detection in coherent lidar is analyzed.Mathematical modeling and signal-to-noise ratio of the balanced detection process is deduced.A numerical simulated system is established.For the same input signal，when the beam-splitter coefficient of balanced coherent detection is between 0Balanced receiver technique for signal detection in coherent lidar is analyzed.Mathematical modeling and signal-to-noise ratio of the balanced detection process is deduced.A numerical simulated system is established.For the same input signal，when the beam-splitter coefficient of balanced coherent detection is between 0.293 and 0.707,the signal-to-noise ratio of balanced coherent detection is higher than that of single detector coherent detection.And also direction of the wind can be obtained using the balanced detection technique，and experiment results are consisted well with simulation results..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 1064 (2010)
Characteristics of Temporal Wave-form and Frequency Spectrum of Broad-band Laser Pulse Stacked by Chirped Pulses
WANG You-wen, CHEN Lie-zun, YOU Kai-ming, and LU Shi-zhuan
The dependence of the temporal wave-form and frequency spectrum of the broad-band laser pulse stacked by chirped pulses on the parameters of the sub-pulses is investigated theoretically and numerically.It is shown that,the temporal wave-form of the broad-band lasers stacked by the transform-limited pulses is usually smThe dependence of the temporal wave-form and frequency spectrum of the broad-band laser pulse stacked by chirped pulses on the parameters of the sub-pulses is investigated theoretically and numerically.It is shown that,the temporal wave-form of the broad-band lasers stacked by the transform-limited pulses is usually smoothing,while that stacked by chirped pulses takes detrimental modulation.And the former consists of one spectrum line,while the latter consists of multiple spectrum lines.In addition,with the delay-time between neighboring sub-pulses increasing,the modulation riding on the broad-band laser pulse increases,and results in the spectrum lines of the output pulse to increase.The results can help in generating broad-band laser pulse of specific temporal wave-form and frequency spectrum by optimize parameters of the sub-pulses..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 1070 (2010)
High Repetition Rate LD-end-pump Acousto-optic Q-switched Intracavity Frequency Doubling Green Laser
WANG Qiu-ming, LIN Yong-qin, WANG Xin, WANG Jing, and YAN Cai-fan
A high effect green laser is realized by acousto-optic (A-O) Q- switched intracavity frequency doubling Nd∶YVO4 /KTP laser,which is formed with a simple two-mirror line cavity.The TEM00 mode green light power of 999 mW is obtained with 1 608 mW of an input 1 064 nm fundamental pump power at the pulse repetition rate ofA high effect green laser is realized by acousto-optic (A-O) Q- switched intracavity frequency doubling Nd∶YVO4 /KTP laser,which is formed with a simple two-mirror line cavity.The TEM00 mode green light power of 999 mW is obtained with 1 608 mW of an input 1 064 nm fundamental pump power at the pulse repetition rate of 40 kHz.The corresponding to optical-optical conversion efficiency is up to 62.1%.The spectral width (full width at half maximum) of green laser is about 0.11 nm or less.±1.2% instabilityof output power is obtained..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 1078 (2010)
Experimental Research on Temporal Characteristics of PPMgLN-OPO
WANG Hong-jie, ZHAI Yong-cheng, JIN Shuai, YU Li-wei, CUI Hai-xu, and YAN Cai-fan
An optical parametric oscillator based on periodically poled MgO doped lithium niobate ( PPMgLN-OPO) is reported.The output temporal characteristics of PPMgLN-OPO are discussed by varying its domain period and temperature tuning as well as pump power.In this experiment,the pulse width of pumping light and signal light An optical parametric oscillator based on periodically poled MgO doped lithium niobate ( PPMgLN-OPO) is reported.The output temporal characteristics of PPMgLN-OPO are discussed by varying its domain period and temperature tuning as well as pump power.In this experiment,the pulse width of pumping light and signal light is measured respectively by adopting MOTORULA′s Si-diode and JUDSON′s InGaAs diode as detectors.LD end-pumped Q-switched Nd∶YVO4 laser operating at a repetition rate of 19 kHz is used as pump source,when the pump power is 1 008 mW,PPMgLN-OPO produces the signal output power of 238 mW with the smallest pulse width of 9.3 ns,its optical-optical conversion efficiency is 23.6%,and the pulse width of signal wave is narrowed significantly..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 1082 (2010)
Ultraviolet Nanoimprint Lithography for Fabricating Fresnel Lens
ZOU Jian-bing, PU Dong-lin, SHEN Su, and CHEN Lin-sen
In view of the drawbacks of Fresnel lens in the traditional condenser optical system,which needs high cost and the light intensity distribution is uneven,a method of fabricating Fresnel lens by ultraviolet nanoimprint lithography is put forward.The mold of Fresnel lens is designed through ray-tracing theory of geometriIn view of the drawbacks of Fresnel lens in the traditional condenser optical system,which needs high cost and the light intensity distribution is uneven,a method of fabricating Fresnel lens by ultraviolet nanoimprint lithography is put forward.The mold of Fresnel lens is designed through ray-tracing theory of geometrical optics.The mold is imprinted by the ultraviolet nanoimprint lithography system.And after employing UV light to cure the resin,the ultra-thin Fresnel lens is fabricated.The optical properties of the ultra-thin Fresnel lens on are tested and analyzed in the sunshine.And the results show that the Fresnel lens which has low cost,high concentration and even light intensity destribution can be realized..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 1085 (2010)
Influence of 60Co Radiation Damage on Performance of Light Emitting Diode
HU Jin, DU Lei, ZHANG Hai-hui, and YANG Guang-lin
The Light Emitting Diode model is presented based on the scattering theory.Taking the influence of low dose ionization radiation damage into consideration,the model of the relationship between device scattering factors and radiation damage is introduced.Over a wide range of input current,the electrical characteristics The Light Emitting Diode model is presented based on the scattering theory.Taking the influence of low dose ionization radiation damage into consideration,the model of the relationship between device scattering factors and radiation damage is introduced.Over a wide range of input current,the electrical characteristics of devices are meassured for different ionization radiation situations.The experimental results agree well with the proposed models.After the analysis of the experimental results and the above-mentioned models,the relationship between low dose ionization radiation damage and Light Emitting Diode performance degradation is studied.It is proved that with increasing electron density in recombination center，the interface trap density and scattering probability increase slightly,which leads to slight degradation of I-V and L-V characteristics in Light Emitting Diode .Because heavy particle radiation can cause displacement effect directly,which leads to significant increase of interface trap density,heavy particle radiation has much more influence on the performance of Light Emitting Diode than ionization radiation..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 1089 (2010)
Focusness Evaluation for Digital Refocusing Light Field Photography
ZHOU Yu, YUAN Yan, HU Huang-hua, and ZHANG Xiu-bao
The focusness detection methods for digital refocusing both in spatial and frequency domain are presented.The spatial method reduces the data used in image reconstruction according to the selected evaluation area.And the frequency domain method embeds the evaluation functions in image reconstruction.The experimental reThe focusness detection methods for digital refocusing both in spatial and frequency domain are presented.The spatial method reduces the data used in image reconstruction according to the selected evaluation area.And the frequency domain method embeds the evaluation functions in image reconstruction.The experimental results show that the improved methods are faster than the conventional..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 1094 (2010)
Dispersion Compensation in Optical Coherence Tomography
LIN Lin, GAO Ying-jun, LONG Bing-chang, CAI Li-yu, and HE Yong-jian
In order to solve the problem that dispersion in dispersive material restricts improvement of depth resolution of optical coherence tomography(OCT)with broadband optical source.a numerical posteriori dispersion compensation technique for optical coherence tomography depth-scan signals is presented.The relationship betwIn order to solve the problem that dispersion in dispersive material restricts improvement of depth resolution of optical coherence tomography(OCT)with broadband optical source.a numerical posteriori dispersion compensation technique for optical coherence tomography depth-scan signals is presented.The relationship between resolution of optical coherence tomography and FWHM of optical source is analyzed.In experience,1 550 nm optical source and fiber Michelson interferometer are used to get imaging signal from planes in the water.Data of the image are compensated up to the third order optical dispersion of water and rapid optical delay line.A tunable phase factor is introduced to improve the results of compensation.Examples of dispersion compensated depth-scan signals obtained from microscope cover glasses under water and muscle tissue of mouse are presented..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 1099 (2010)
Research on Sampling and Computer Simulation of Mask-based Light Field Photography
CHANG Lei, YUAN Yan, ZHANG Xiu-bao, and ZHOU Zhi-liang
Light field photography is a new imaging technology with a patterned mask inserted between lens and sensor in a conventional camera.The mask attenuates the incident light rays and the sensor records both 2D spatial and 2D directional information.Sharp images at different depths could be calculated from reconstructed 4DLight field photography is a new imaging technology with a patterned mask inserted between lens and sensor in a conventional camera.The mask attenuates the incident light rays and the sensor records both 2D spatial and 2D directional information.Sharp images at different depths could be calculated from reconstructed 4D light field.This paper establishes computer modeling of light field camera,and proposes a method of reducing computational amount due to sampling theorem on the premise of image quality assurance.It is proved in the computer simulation..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 1104 (2010)
Measuring the Tip-tilt Angles of the Active Mirror in the Stellar Interferometer
LU Yi, FAN Wei-jun, and KONG Ming
Using laser interference technology,computer control technology and data image processing technology,the CCD interferometer measuration system is designed.Then,the mathematical model between the interferogram and the tip-tilt angles is deduced.After preprocessing the interferogram and thinning the fringes,least square Using laser interference technology,computer control technology and data image processing technology,the CCD interferometer measuration system is designed.Then,the mathematical model between the interferogram and the tip-tilt angles is deduced.After preprocessing the interferogram and thinning the fringes,least square method is used to fit the fringes.Based on equal thickness interferometer theory,the tip-tilt angle parameters of the active mirrors are obtained.The X axis′s movement range is 56″.872,and the resolution is 0″.113.The Y axis′s movement range is 49″.835,and the resolution is 0″.112..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 1115 (2010)
Application of a Multi-algorithm Fusion Real Time Filter in FOGs
LIU Ying, LI Yan, and XU Jin-tao
A method of multi-algorithm fusion real time filter was researched on the basis of the characteristic of the output signals of fiber optic gyros(FOGs),Mallat wavelet transform theory and the requirements of FOG in the application environment.The IIR filtering is adopted to deal with the signal while the data is few in A method of multi-algorithm fusion real time filter was researched on the basis of the characteristic of the output signals of fiber optic gyros(FOGs),Mallat wavelet transform theory and the requirements of FOG in the application environment.The IIR filtering is adopted to deal with the signal while the data is few in the initial sample time,a moving window is adopted to realize the wavelet real time filter,and period symmetry extend method to eliminate the problem of the boundary.The method can eliminate the high frequency noise,and the random drift is restrained.Experimental results show the feasibility and efficiency of the method in FOGs signals de-noising..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 1116 (2010)
Infrared Optical Properties of VO2 Nano-array
YU Xiao-jing, LI Yi, WANG Hai-fang, HUANG Yi-ze, ZHANG Hu, ZHANG Wei, and ZHU Hui-qun
The interaction of scattering light between nanoparticles in nano-array is considered in its phase transition from semiconductor to metal.The mathematical model of vanadium dioxide nanoparticle is established based on the absorption and scattering properties of small particles,and the property of complex refractive chaThe interaction of scattering light between nanoparticles in nano-array is considered in its phase transition from semiconductor to metal.The mathematical model of vanadium dioxide nanoparticle is established based on the absorption and scattering properties of small particles,and the property of complex refractive changing with the various different temperature and wavelength.The results show that the main contribution to the optical response with wavelength is absorption cross section in the infrared,and the absorption peak of metal phase is near 980 nm.The change of extinction coefficient is larger in the infrared region than in the visible region.The study indicated that the extinction cross section of nano-array is depended on the distance between particles.When the distance between particles increases,the peak position of extinction cross section appears red-shift and the peak value of extinction cross section increases.However,when the distance is more than a certain value,the peak will decrease.The vanadium dioxide nano-array is prepared by magnetic reactive sputtering with the mask of porous alumina.The measurement results show that the transmittance of nano-array is higher than the transmittance of vanadium dioxide film..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 1120 (2010)
Measurements of Infrared Materials Refractive-index Using Infrared Interferometer
HE Jun, CHEN Lei, and WANG Qing
The refractive index of infrared material is measured using the infrared Twyman-Green interferometer.By adding a rotation stage in the test arm,the OPD of the test piece placed on the stage is changed with the rotation and the interference fringe is shifted.The refractive index of the test piece can be calculated by thThe refractive index of infrared material is measured using the infrared Twyman-Green interferometer.By adding a rotation stage in the test arm,the OPD of the test piece placed on the stage is changed with the rotation and the interference fringe is shifted.The refractive index of the test piece can be calculated by the recorded values of rotating angle and shifting fringe.The result shows that the refractive index of germanium crystal is 4.003 and the refractive index of GeAsSe is 2.494 when the temperature is 25 ℃ and the wavelength is 10.6 μm.The measurement error of the method is 10－3 ,which indicates that the precision can be improved if the test piece is thicker or its refractive index is lower..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 1125 (2010)
Dim Infrared Targets Detection Based on Adaptive Bilateral Filtering
LI Fan, LIU Shang-qian, and QIN Han-lin
A adaptive bilateral filtering method is presented for background prediction in small targets detection of infrared images.To improve the performance of small targets detection,the true image background is estimated adaptively via nonlinear combination based on low-pass domain filter and the gray level information of iA adaptive bilateral filtering method is presented for background prediction in small targets detection of infrared images.To improve the performance of small targets detection,the true image background is estimated adaptively via nonlinear combination based on low-pass domain filter and the gray level information of images.Simulations and experiments show that the algorithm is more efficient to detect the small target from complicated background compared with the method based on wavelet filtering..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 1129 (2010)
Optical Measuring Concentration of DOP Aerosol
MA Ying, LIU Qun, QIU Dan-gui, SHI Ying-xia, HOU Jian-Rong, and YIN Wang-Bao
In order to ensure the work efficiency of High Efficiency Particulate Air Filter(HEPA),Dioctylphthalate method,which is widely used in the efficiency and leaking test of HEPA filtration system,is analyzed.The optical detect theory of Ddictylphthalate aerosol concentration is summarized.Based on Mie scattering theory,a In order to ensure the work efficiency of High Efficiency Particulate Air Filter(HEPA),Dioctylphthalate method,which is widely used in the efficiency and leaking test of HEPA filtration system,is analyzed.The optical detect theory of Ddictylphthalate aerosol concentration is summarized.Based on Mie scattering theory,a mathmatical model is derived on relation between light-scattering intensity and concentration of aerosol when the special aerosol is generated.The optical measurement system based on the theory is designed and manufactured.The validity of the model is testified by the experiment.The experimental result shows that there is a good linear relation between light-scattering intensity and mass concentration of Dioctylphthalate aerosol..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 1132 (2010)
Study of the Phase-recovering Algorithm for Saturated Fringe Patterns in the Projection Grating Phase-shifting Profilometry
HU Er-yi, and LI Yan
The phase error caused by intensity saturation in the projection grating phase-shifting profilometry is studied.The applicability ranges of phase-recovering algorithms corresponding to different intensity saturation coefficients of N frame phase-shifting technique are studied.The formula of the phase-recovering algoritThe phase error caused by intensity saturation in the projection grating phase-shifting profilometry is studied.The applicability ranges of phase-recovering algorithms corresponding to different intensity saturation coefficients of N frame phase-shifting technique are studied.The formula of the phase-recovering algorithm corresponding to seven-frame phase-shifting method is deduced.The theoretical analysis indicates that the applicability range of the phase-recovering algorithm will be extended with the increasing of phase-shifting steps.Finally，some Simulative and experimental results are presented to prove the availability of the phase-recovering algorithm.The phase error caused by the image intensity saturation can be effectively decreased by the phase-recovering algorithm based on seven-step phase-shifting technique..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 1137 (2010)
A New Measuring Method of Laser Positional Error on Moving Platform
DANG Li-ping, TANG Shu-gang, and ZHOU Zhou
Combining quadrant detector and fast steering mirror,a new measuring method of the positional error of laser beam on moving platform is proposed.In this method,the fast steering mirror is used to stabilize axis direction of outputting laser beam and the quadrant detector is used to measure the corresponding change of rCombining quadrant detector and fast steering mirror,a new measuring method of the positional error of laser beam on moving platform is proposed.In this method,the fast steering mirror is used to stabilize axis direction of outputting laser beam and the quadrant detector is used to measure the corresponding change of return laser position,then the coupling action between fast steering mirror and the movement of tracking platform is separated in order to get the angle between laser axis and line-of-sight of target.According to this,it can be concluded that the axis of the laser at the target steadily and guide the missile attacking precisely.This method is suitable for real time processing and it is suitable to the laser guided weapons with second class guiding time at last stage trajectory..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 1143 (2010)
System of Speed-measurement by Flash Imaging Based on High Power LED
LEI Juan, BAI Yong-lin, XIONG Fa-tian, and YANG Wen-zheng
A non-contacted speed-measurement system for high speed moving objects is designed.During one single frame exposure time of CCD,the flashlight flares to a moving object twice and the two corresponding images of the object are captured by CCD in sequence.The movement speed of the object can be determined from the displaA non-contacted speed-measurement system for high speed moving objects is designed.During one single frame exposure time of CCD,the flashlight flares to a moving object twice and the two corresponding images of the object are captured by CCD in sequence.The movement speed of the object can be determined from the displacement of the images versus their interval time.This system has the advantage of real-time measurement,thus it breaks through the limitation of single point measurement technology in space.Moreover,it can acquire not only the spacial information of one point at different moments,but also the information of different space points at the same moment..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 1148 (2010)
Fiber Optics and Optical Communications
Design of Optical Comb Filters Based on Cascaded Phase-Shifted Linearly Chirped Fiber Gratings
ZHOU Jun, YUAN Hong-wei, XU Tie-feng, ZHANG Ling-fen, and MA Wei-tao
A novel optical comb filter is designed with two cascaded phase-shifted linearly chirped fiber gratings.According to the transmission matrix method and Fabry-Perot resonant cavity theory,the characteristics of reflection spectrum of the optical comb filter are numerically analyzed for the different combinations of two A novel optical comb filter is designed with two cascaded phase-shifted linearly chirped fiber gratings.According to the transmission matrix method and Fabry-Perot resonant cavity theory,the characteristics of reflection spectrum of the optical comb filter are numerically analyzed for the different combinations of two chirp gratings,the value of chirp,the index modulation and the phase-shift.The results show that the distribute density of reflection peaks is different for the different combinations of two chirp gratings,that is,the spacing between reflection peaks is equal if the signs of two chirps same,it can be used to design a uniform filter; on the other hand,the distribute of reflection peaks shows the characteristic density gradient if the signs of two chirps opposite,which can be used to design a non-uniform filter.And the greater the chirp of gratings,the wider the bandwidth of reflection spectrum of the filter,and the lower the reflectivity; however, the reflectivity will be improved with the increase of index modulation; furthermore each of the reflection peaks moves with the change of phase-shift,which is useful to select a filter window by changing the phase-shift..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 961 (2010)
Optical Code Division Multiple Access System with Optical Hard-limiter and Parallel Interference Cancellers under Multiple Noise Background
LI Xiao-bin, WANG Li-chao, HUANG Huan-bin, and WANG Fu-qiang
To suppress multiple access interference and multiple noises existing in optical code division multiple access system,a system with hard-limiter and parallel interference canceller based on maximal value decision is presented.The effect of suppress multiple access interference is examined while APD noise and thermal noTo suppress multiple access interference and multiple noises existing in optical code division multiple access system,a system with hard-limiter and parallel interference canceller based on maximal value decision is presented.The effect of suppress multiple access interference is examined while APD noise and thermal noise exist.Optical orthogonal code is applied as address code,APD is used as opto-electro detector,and bit error rate of the system is derived and analyzed.Simulations based on the expression are done and comparison with other multi-user interference suppressing methods is made.Compared with other effective methods such as single bit with single hard-limiter,single bit with double hard-limiters,multiple-bit transmitted method,multiple-bit transmitted with hard-limiter method,parallel interference canceller(without hard-limiter) based maximal value decision method and so on,simulation results show that the effect of suppress multiple access interference of the system is superior to parallel interference canceller without hard-limier and multiple-bit transmitted method with or without hard-limiter.If the received power is low,the system is also superior to double hard-limiters method.So,it is effective for suppressing multiple access interference and multiple noises..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 967 (2010)
Performance of Magnetooptic Fiber Bragg Grating Filters for All-Optical Clock Extraction
WEI Jin-zhe, WU Bao-jian, and WEN Feng
The reflection spectra of polarization-mode conversed light in Magnetooptic Fiber Bragg Gratings (MFBGs) dependent on the magnetooptical coupling intensity is investigated.According to the magnetooptic coupled-mode theory combined with the propagation property of fiber Bragg grating,the magnetic control characteristicsThe reflection spectra of polarization-mode conversed light in Magnetooptic Fiber Bragg Gratings (MFBGs) dependent on the magnetooptical coupling intensity is investigated.According to the magnetooptic coupled-mode theory combined with the propagation property of fiber Bragg grating,the magnetic control characteristics of the MFBGs are analyzed numerically.The 3 dB bandwidth tunable filter is obtained by adjusting the magnetooptical coupling intensity.The clock extraction of 40 Gbps RZ data signal by utilizing the comb filtering of MFBGs under bias magnetic fields is simulated and the jitter performance of the MFBGs is also analyzed..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 972 (2010)
Physical Optics
Dispersion of Liquid Crystal Wavefront Correctors
LIU Zhao-nan, LI Chao, XIA Ming-liang, LI Da-yu, and XUAN Li
The research on the dispersion of liquid crystal wavefront correctors is introduced,using the lens of 250D focus,250D astigmatism and the narrow band filter of 650 nm,670 nm,710 nm,840~860 nm,835~865 nm,830~870 nm.For the 850 nm near-infrared light,when the waveband below 30 nm,the dispersion of liquid crystal wavefronThe research on the dispersion of liquid crystal wavefront correctors is introduced,using the lens of 250D focus,250D astigmatism and the narrow band filter of 650 nm,670 nm,710 nm,840~860 nm,835~865 nm,830~870 nm.For the 850 nm near-infrared light,when the waveband below 30 nm,the dispersion of liquid crystal wavefront correctors has little affect to the system,which can be working with high energy; when the waveband over 40 nm,the affect will not be overlooked.Dispersion of liquid crystal of visible light is almost the same as near-infrared.As conclusion,the waveband that the liquid crystal wavefront correctors may correct with high energy and small dispersion is assured to be 30nm to 40 nm at visible range..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 1014 (2010)
Attenuation Characteristics of Laser in the Randomly Distributed Soot Agglomerates
LEI Cheng-xin, WU Zhen-sen, ZHANG Hua-fu, and LIU Han-fa
Based on fractal theory,the cluster-cluster aggregation (CCA) model is used to simulate the fractal structure of the soot agglomerates with random distribution,and the properties of single scattering of randomly distributed soot agglomerates are studied using the discrete dipole approximation (DDA) method.Then the laseBased on fractal theory,the cluster-cluster aggregation (CCA) model is used to simulate the fractal structure of the soot agglomerates with random distribution,and the properties of single scattering of randomly distributed soot agglomerates are studied using the discrete dipole approximation (DDA) method.Then the laser attenuation characteristics in the randomly distributed soot cluster agglomerates are studied using Monto Carlo method.The effects of the incident angle,laser wavelength,number concentration,the number and diameter of primary particles in soot agglomerates on the attenuation properties of laser are discussed.The research result provides theoretical basis to the propagation and attenuation characteristics of laser in the complex random medium..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 6, 1021 (2010)
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