Journals >Acta Photonica Sinica
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2006
Volume: 35 Issue 2
38 Article(s)
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Research Article
The Theoretic Analysis on the Efficiency in the Cr4+∶YAG Solid-state Laser
Yu Xianlun, Yang Bojun, and Yu Li
The efficiency of the solid-state laser is one of the key technolygy in practice. The intrinsic efficiency of the Cr4+∶YAG solid-state laser as the absorption efficiency,quantum efficiency,storage efficiency and extraction efficiency has been discussed in this paper. The absorption cross section,the stimulated emissionThe efficiency of the solid-state laser is one of the key technolygy in practice. The intrinsic efficiency of the Cr4+∶YAG solid-state laser as the absorption efficiency,quantum efficiency,storage efficiency and extraction efficiency has been discussed in this paper. The absorption cross section,the stimulated emission cross section,the high energy level lifetime and the dopant ion concentration of the Cr4+∶YAG crystals would obviously affect the intrinsic efficiency of this laser. The efficiency of the Cr4+∶YAG solid-state laser will be largely improved when the optical quality and the dopant concentration in the Cr4+∶YAG crystals are increased and when the operated wavelength of pump and the design of the Cr4+∶YAG laser cavity is optimized..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 161 (2006)
Study on Energy Transfer in LHC Ⅱ of Bryopsis Corticulans by Femtosecond Spectra
Zhang Sujuan, Wang Shuicai, He Junfang, and Chen Hui
Based on the technique of Time Correlated Single Photon Counting(TCSPC),energy transfer kinetics among chlorophylls in a monomeroic unit of major light-harvesting complex (LHC Ⅱ) from bryopsis corriculan were studied. In the chlorophyll Q region,six characteristic molecules marked as Chlb630,Chlb642,Chla(653,652),Chla(Based on the technique of Time Correlated Single Photon Counting(TCSPC),energy transfer kinetics among chlorophylls in a monomeroic unit of major light-harvesting complex (LHC Ⅱ) from bryopsis corriculan were studied. In the chlorophyll Q region,six characteristic molecules marked as Chlb630,Chlb642,Chla(653,652),Chla(667,664),Chla(676,680,675),Chla(683,682) were discriminated. Fluorescence kinetics measured in the chlorophyll Q region was excited by pulsed light of 630 nm(70 fs). After analyzing,results of energy transfer among chls were obtained as following: only～20% of the energy absorbed by Chlb630 is initially transferred directly to other Chls with time constants shorter than 150 fs. Overwhelming part of the energy transfer among chlorophylls occur with time constants longer than 76 ps. Energy transfer pathway with time constants of several hundred femotoseconds and tens of picoseconds were also obtained. The fluorescence lifetimes of Chlb(653,652),Chla(667,664),Chla(676,680,675),Chla(683,682) were determined to be 1.41 ns,1.39 ns,676 ps,709 ps respectively. The percentages of energy dissipation in the pathway of fluorescence emission are no more than 40% in the monomeric unit of LHC Ⅱ..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 166 (2006)
Analysis of Parallel Directional Coupler Using 3D-Semi-vectorial BPM Based on the Variable Transformed Galerkin Method
Zhang Xifei, and Ma Changfeng
A novel three-dimensional semi-vectorial beam propagation method based on the variable transformed galerkin method(3D-VTGM-SBPM) is proposed for directly modeling optical waveguides,and is successfully applied to simulate parallel directional coupler. By adopting proper variable transformation,the basic three-dimensionA novel three-dimensional semi-vectorial beam propagation method based on the variable transformed galerkin method(3D-VTGM-SBPM) is proposed for directly modeling optical waveguides,and is successfully applied to simulate parallel directional coupler. By adopting proper variable transformation,the basic three-dimensional semi-vectorial BPM equations is reduced to a first-order normal differential equation system. The artificial boundary condition is avoided,and the polarization characteristic of the mode field is displayed..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 188 (2006)
Numerical Simulation of Net Gain Characteristics for Step Dopant Er∶Al2O3 Waveguide Amplifier
Li Chengren, Song Changlie, Li Shufeng, Li Jianyong, and Lei Mingkai
The theoretical model of Er-doped waveguide amplifier with longitudinal step-dopand was build.The finite element method,rate equations and propagation equations were used to simulate numerically net gain characteristics of the amplifier. The results show that pumping efficiency of the amplifier is improved. Net gain anThe theoretical model of Er-doped waveguide amplifier with longitudinal step-dopand was build.The finite element method,rate equations and propagation equations were used to simulate numerically net gain characteristics of the amplifier. The results show that pumping efficiency of the amplifier is improved. Net gain and signal output power of step-dopant waveguide amplifier increase 9.2% and 90.5% respectively than uniform-dopant waveguide amplifier. Length of the amplifier,however,is shortened 16.9%..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 192 (2006)
The Study of Optical Microsphere Cavity with a Stratified Structure
Yan Jun, Wang Zongbao, Wang Keyi, and Zhou Shaoxiang
The stratified structured microsphere cavity with high refractive index shell outer its surface was simulated using the finite-difference time-domain method(FDTD). The energy density distributions of whispering-gallery modes(WGM) in the microsphere cavity have been analyzed,and resonance performance of stratified strucThe stratified structured microsphere cavity with high refractive index shell outer its surface was simulated using the finite-difference time-domain method(FDTD). The energy density distributions of whispering-gallery modes(WGM) in the microsphere cavity have been analyzed,and resonance performance of stratified structured microsphere cavities with different shell thickness were compared too. Then the methods to tune the microsphere cavity or to control the resonant modes of microsphere cavity were presented and discussed. With this stratified structure,an effective enhance was achieved for the resonant performance of microsphere cavity(with Q value 30% larger and mode volume 60% smaller than the homogeneous structured microsphere cavity). These studies and results provide new optimizing methods for the subsequent structure design and practical application of microsphere cavity..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 197 (2006)
Analysis of Stress Birefringence for Silica Waveguide on Silicon and SOI Rib Waveguide
He Zhongjiao
The birefringence originated from the residual stress of the silica waveguide on the silicon and the SOI(Silicon on Insulator) rib waveguide is analyzed using the finite element method. It is found that the coefficient of the stress birefringence is of the order of 10－4 for the silica waveguide on the silicon;the coeffThe birefringence originated from the residual stress of the silica waveguide on the silicon and the SOI(Silicon on Insulator) rib waveguide is analyzed using the finite element method. It is found that the coefficient of the stress birefringence is of the order of 10－4 for the silica waveguide on the silicon;the coefficient is of the order of 10－5 and 10－3 for the SOI rib waveguide covered by air and SiO2 respectively. It can be seen that the large birefringence arise in the silica waveguide on the silicon and the SOI rib waveguide covered by the SiO2 while there is small birefringence in the SOI rib waveguide covered by air..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 201 (2006)
Study on Optic Properties of Silicone Resin
Zhang Xiaokang, Liao Changjun, Feng Zhouming, Wu Yangzhe, Cai Jiye, Ye Xiaojing, and Liu Songhao
A high-resistant one was selected from several silicone resins. There was no absorption peak in the spectrum of 300 nm to 3000 nm according to the transmittance of the film material from 185 nm to 104 nm.The refractive indexes and extinction coefficients in the wavelengths of 600 nm to 1600nm were deduced by the methodA high-resistant one was selected from several silicone resins. There was no absorption peak in the spectrum of 300 nm to 3000 nm according to the transmittance of the film material from 185 nm to 104 nm.The refractive indexes and extinction coefficients in the wavelengths of 600 nm to 1600nm were deduced by the method of Manifacier,which were 1.513 and 0.0006 at 650 nm,respectively(at 26℃) and would decreased to 1.512 and 1.489 after exposed to UV for two hours. Polarization dependence wasn't detected by laser-V-prism device. The scattering loss of the film was less than 0.5 dB/cm based on the analysis of the surface characteristic with an RMS roughness of 1.7 nm and transmission loss. These results proved that this silicone resin could be valuable in the making of waveguide devices used in plastic optic fiber communication system..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 205 (2006)
The Spectroscopic Properties of Er3+-doped TeO2-Nb2O5 Glasses with High Mechanical Strength Performance
Wu Jialu, Dai Shixun, Zhang Junjie, Hu Lili, and Jiang Zhonghong
Er3+-doped(100－x) TeO2－xNb2O5(x=5,10,15,20 mol%) niobic tellurite glasses were synthesized,and their density,refractive index,glass transition temperature,crystallization temperature,Vickers microhardness,absorption spectra,fluorescence spectra and the lifetimes of Er3+: 4I13/2 level were measured. The Judd-Ofelt strenEr3+-doped(100－x) TeO2－xNb2O5(x=5,10,15,20 mol%) niobic tellurite glasses were synthesized,and their density,refractive index,glass transition temperature,crystallization temperature,Vickers microhardness,absorption spectra,fluorescence spectra and the lifetimes of Er3+: 4I13/2 level were measured. The Judd-Ofelt strength parameters Ωt(t=2,4,6) and the stimulated emission cross-section (σemi) were calculated by Judd-Ofelt theory and McCumber theory,respectively. The compositional dependence of optical parameters of Er3+ in glass samples wase investigated. The properties of Er3+-doped niobic tellurite glasses were compared with that of the typical 75TeO2－20ZnO－5Na2O(TZN) tellurite glass in aspect of thermal,mechanical,spectroscopic properties and amplification merit..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 209 (2006)
The Research of Spectral Matching Factors Under the Laser Aids
Di Huige, and Liu Lei
The change of spectral matching factors between photo cathode and reflecting spectrums of scenes is analyzed,when the laser aids system is used. Its expression is given,and the character and significance of the expression are analyzed. The spectral matching factor is calculated between the Super Second Generation PhotoThe change of spectral matching factors between photo cathode and reflecting spectrums of scenes is analyzed,when the laser aids system is used. Its expression is given,and the character and significance of the expression are analyzed. The spectral matching factor is calculated between the Super Second Generation Photo Cathode(New S25,Super S251,Super S252) and scenes by the laser. And the results are 0.833,0.72 and 0.56,which proves the laser(λ=850 nm) is reasonable. The character of matching factor under laser aids is discussed and analyzed. All of above is with practical value in the evaluation of visual range of night vision systems when the laser aids system is used..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 214 (2006)
Detection of Dissolved Organic Matter Concentration Using Laser-Induced Fluorescence Technique
Ding Zhiqun, Liu Wenqing, Zhang Yujun, Li Hongbin, Wei Qingnong, Zhao Nanjing, Chen Dong, and Yang Lishu
The polluted water column is excited with the third harmonics(355 nm) of Nd∶YAG laser and fluorescence spectrum is detected by laser induced fluorescence technique. After analysed and processed the spectrum data,normalization of fluorescence intensity is obtained,which is the ratio of 450 nm value to 405 nm value. CommThe polluted water column is excited with the third harmonics(355 nm) of Nd∶YAG laser and fluorescence spectrum is detected by laser induced fluorescence technique. After analysed and processed the spectrum data,normalization of fluorescence intensity is obtained,which is the ratio of 450 nm value to 405 nm value. Commercial humic acid is diluted with different quantity of deionized water as water sample of known DOM concentration. The result has been shown that there is a good correlation between DOM concentration and the normalization fluorescence intensity of ultraviolet laser induced fluorescence. Therefore the LIF technique is a good method for the practical utilization of in vivo monitoring polluted water column..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 217 (2006)
The Optical Properties of AIN Film
Yan Guojun, Chen Guangde, Qiu Fusheng, and Zhaoyan Fan
An X-diffraction,a transmittance spectrum and absorption spectrums at different temperatures of an AIN film deposited on a(001) SiC substrate by MBE were measured on a X-diffractometer and an UV spectrophotometer(190nm～800nm) respectively. The X-diffraction spectrum shows that: there are strains in the c-axial orientatAn X-diffraction,a transmittance spectrum and absorption spectrums at different temperatures of an AIN film deposited on a(001) SiC substrate by MBE were measured on a X-diffractometer and an UV spectrophotometer(190nm～800nm) respectively. The X-diffraction spectrum shows that: there are strains in the c-axial orientation of the AIN,these sstrains are caused by the dismatching of crystal lattice constant of the AIN and the SiC substrate,and these stains will cause the stresses in the AIN film;the transmitrtance spectrum of the AIN shows that: the direct-band-gap of the AIN is about 6.2 eV;and obvious“knees”or a“shoulders”structure around 6.2 eV existing in the absorption spectrums are considered to the caused by the free excitonic absorptions in the AIN film,if not considered the formation energy of the free exciton,6.2 e is the value of the direct-band-gap of the AIN film;the“kness”or the“ shoulder”structure and position don't change with the temperature in the absorption spectrums of the AIN shows that: the temperature doesn't influence the value of the direct-band-gap of the AIN obviously,this is probable,which is caused by the stresses existing in the AIN film..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 221 (2006)
Influence of Deposited Pressure on Refractive Index and Packing Density of ZrO2 Coatings by Electron Beam Evaporation
Hao Dianzhong, Wu Fuquan, Ma Lili, Yan Bin, and Zhang Xu
ZrO2 coatings were prepared by electron beam evaporation at different deposition pressure,while deposition rate was monitored and demonstrated by quartz crystal oscillation. Used the new spectroscopic ellipsometer and spectrophotometer to test about the ZrO2 deposited spectral character and measure the film refractive ZrO2 coatings were prepared by electron beam evaporation at different deposition pressure,while deposition rate was monitored and demonstrated by quartz crystal oscillation. Used the new spectroscopic ellipsometer and spectrophotometer to test about the ZrO2 deposited spectral character and measure the film refractive index. Calculated the packing density of thin-film according to wavelength deviation dispersion theory before and after the thin-film suck tide. It was found that the refractive index and packing density were increasing as the working pressure was decreasing..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 224 (2006)
The Monitoring System and the Analysis of Locating Theory for Pipeline Leakage Detection Based on Single Distributed Optical Fiber Sensor
Tan Jing, Chen Weimin, Zhu Yong, and Wang Ding
The pipeline leakage detecting and locating system based on Sagnac interferometer and distributed optical fiber technology has many advantages,such as the long monitoring range and the high precision in fault locating. In the prototype,the non-sensing fiber portion of the Sagnac ring must be shielded to avoid disturbanThe pipeline leakage detecting and locating system based on Sagnac interferometer and distributed optical fiber technology has many advantages,such as the long monitoring range and the high precision in fault locating. In the prototype,the non-sensing fiber portion of the Sagnac ring must be shielded to avoid disturbance,which will restrict the application in actual monitoring system. To address this problem,a new optical configuration was put forward in this paper. It adopted one optical fiber line as sensing part instead of the optical fiber ring,and some necessary modifications were made to remove the effect of the fiber birefringence. A theoretical analysis of optical path and locating method were also given in this paper,which demonstrated the feasibility of pipeline intrusion(or leakage) detecting and locating by this system..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 228 (2006)
A Novel Packaged Fiber Bragg Grating Temperature Sensor with High Temperature-resistance
Yu Dakuan, Qiao Xueguang, Jia Zhenan, Sun An, and Wang Min
The principle of fiber Bragg grating sensing is analyzed. Fiber Bragg grating(FBG) is placed in a thin metal tube and a special kind of high temperature-resistance pastern felts with two ends of the metal tube to make FBG not to fall off. Tensile force is put on the FBG by the screw thread in the process of encapsulatiThe principle of fiber Bragg grating sensing is analyzed. Fiber Bragg grating(FBG) is placed in a thin metal tube and a special kind of high temperature-resistance pastern felts with two ends of the metal tube to make FBG not to fall off. Tensile force is put on the FBG by the screw thread in the process of encapsulation,which ensures the FBG tightening in changeable temperatures out of environment. It is found that the structure of FBG temperature sensor has good repeatability and linearity. The experimental results show that the temperature response sensitivity is 0.0252 nm/℃,and the response curve is linear,and the whole measuring range is over 200℃ at least. The FBG temperature sensor can be used in high temperature environment..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 232 (2006)
The Hybrid Refractive-Diffractive Optical Coupler for Image Guide Fiber Bundle
Li Dongyuan, Yan Xiusheng, Zhang Xiaoguang, Hou Lantian, Zhou Guiyao, and Yin Tie
Optical coupler is designed with diffractive surface. According to the third order aberration theory of binary optical element,the method to calculate the initial structure parameter of binary surface was presented. The result of design with one diffractive surface is shown with calculation and optimization of optical Optical coupler is designed with diffractive surface. According to the third order aberration theory of binary optical element,the method to calculate the initial structure parameter of binary surface was presented. The result of design with one diffractive surface is shown with calculation and optimization of optical design software ZEMAX,whose operating wavelength,focal length,optical length respectively is 0.4～0.7 μm,27.5 mm,64 mm. The result is available for image guide fiber bundle,whose single core diameter is 16 μm and section diameter is 6 mm. Compared with the conventional optical coupler,the hybrid refractive-diffractive systems offer considerable reduction in the apparent size,weight,and improve the imaging quality..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 235 (2006)
Determining the Parameters of VPHG with the Diffractive Efficiencies Ratio(+1/－1)
Li Jianlong, Fu Kexiang, Zhu jianhua, Zhang Lijuan, and Zeng Yangsu
A new method is proposed to determinate the parameters of the gratings at the same time by means of the diffractive efficiencies ratio (+1/－1) and simulated annealing algorithm. We make use of the diffraction orders efficiency ratio (m=+1,－1) decrease the error result from the varied degree surface roughness,the aberraA new method is proposed to determinate the parameters of the gratings at the same time by means of the diffractive efficiencies ratio (+1/－1) and simulated annealing algorithm. We make use of the diffraction orders efficiency ratio (m=+1,－1) decrease the error result from the varied degree surface roughness,the aberration in the structure period and the medium distributing uneven etc,in order to ensure to calculation precision in the optimized method. In the experiment of determining the Volume Phase Holographic Grating's parameters,the error of the result is not over l%,so it demonstrates the metrology's validity and feasibility. At the same time,It has a lot of advantages such as no damage,simplicity of measurement,facility of manipulation,good stability and so on.. we believe that the metrology will become the powerful instrument in measurement the grating constant..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 239 (2006)
Study of Holographic Character of a Novel Photopolymer
Wang Airong, Zhai Fengxiao, Wang Sulian, and Huang Mingju
A novel wide band sensitive holographic recording materials co-sensitized by two dyes is presented. The sensitive spectrum of the polymer is dramatically extended from 50 nm to 200 nm. The maximum diffrcation efficiencies are more than 40% and up to 80% in different exposure wavelengths. Four different images are storeA novel wide band sensitive holographic recording materials co-sensitized by two dyes is presented. The sensitive spectrum of the polymer is dramatically extended from 50 nm to 200 nm. The maximum diffrcation efficiencies are more than 40% and up to 80% in different exposure wavelengths. Four different images are stored in the same location of the photopolymer film by the multi-wavelength holographic storage method,and these images can be reconstructed with high quality. It is said that this material is suitable for multi-wavelength holographic storage..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 244 (2006)
True Color Holographic Stereogram
Wang Ding, Yuan Xia, and Huang Jiyang
Two parallactic films of a nature color scene are obtained with a three color grating camera. With the films,a true color holographic stereogram can be made with one-wavelength laser through two exposure recordings. A true color stereoscopic scene image can be reconstructed from the hologram as it is illuminated by a wTwo parallactic films of a nature color scene are obtained with a three color grating camera. With the films,a true color holographic stereogram can be made with one-wavelength laser through two exposure recordings. A true color stereoscopic scene image can be reconstructed from the hologram as it is illuminated by a white light source. Compared with other methods,this method is simpler in operation. It decreases the scattering noise and gets rid of chromatic aberration of the reconstructed image. It canproduce a clearer and brighter achromatic aberration stereoscopic color image..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 248 (2006)
Numerical Investigations of Interactions among Planar Bright Photorefractive Screening Solitons
Ma Yanghua, Zhang Peng, Zhao Jianlin, and Peng Tao
Detailed numerical investigations of the interactions among planar bright photorefractive screening solitons are performed by employing the so-called beam propagation method (BPM). It's found that two in-phase solitons attract each other,and soliton fusions do occur at certain interaction length,which increases monDetailed numerical investigations of the interactions among planar bright photorefractive screening solitons are performed by employing the so-called beam propagation method (BPM). It's found that two in-phase solitons attract each other,and soliton fusions do occur at certain interaction length,which increases monotonously with the initial separation of the two interacting solitons. While in the case of out-of-phase,the two solitons repel each other with a force decreasing monotonously with the initial separation. When the relative phase between the two solitons falls within the ranges of (0,π) and (－π,0),energy transfer will accompany the interactions. Moreover,interactions among multiple solitons could be qualitatively predicted by analyzing those of the neighboring ones..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 252 (2006)
Screening Solitons in Biased Centrosymmetric Photorefractive Media
Li Jinping, Lu Keqing, Zhao Wei, Yang Yanlong, Zhu Xiangping, and Guo Xiaohui
The space-charge field with a higer-order nonlinearity in biased centrosymmetric photorefractive media is presented. When the higer-order term can be neglected,this space-charge field is that studied previously in biased centrosymmetric photorefractive media. The nonlinear wave equation with a higerorder nonlinearity iThe space-charge field with a higer-order nonlinearity in biased centrosymmetric photorefractive media is presented. When the higer-order term can be neglected,this space-charge field is that studied previously in biased centrosymmetric photorefractive media. The nonlinear wave equation with a higerorder nonlinearity is investigated in biased centrosymmetric photorefractive media,which can exhibit bright and dark spatial solitons under appropriate conditions. The nonlinear change in the refractive index in centrosymmetric photorefractive media resulted from the quadratic electro-optic effect,rather than the linear electro-optic effect in noncentrosymmetric media. The stability of these spatial solitons is discussed using beam propagation methods,and it has been found that optical spatial solitons in biased centrosymmetric photorefractive media are stable against small perturbations in amplitude not broken up..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 257 (2006)
Iterative Least Square-Based Algorithm for Nonuniformity Correction of Infrared Focal Plane Arrays
Xu Tianhua, and Zhao Yigong
Based on the iterative least square and image registration technology,the iterative least square based algorithm (ILS) for nonuniformity correction of infrared focal plane arrays was presented,which greatly reduced the time and space complexity and made real-time realization of the image process possible.The ILS algoriBased on the iterative least square and image registration technology,the iterative least square based algorithm (ILS) for nonuniformity correction of infrared focal plane arrays was presented,which greatly reduced the time and space complexity and made real-time realization of the image process possible.The ILS algorithm had the strength of accurate estimation of FPN,fast convergence rate and low computational complexity. The deduction of the algorithm has been presented and the effectiveness has been demonstrated by the simulation results..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 261 (2006)
The Technology of Invasive Measurement of Thermal Response in Laser Medicine
Zhao Youquan, Fan Shifu, Li Xiaoxia, and Li Liyong
The invasive irradiation temperature measurement was applied to trace the process of thermal interaction between lasers and bio-tissues. Portable Infrared thermal detector has inside LD red introductive light and can make a sound when aiming at an object. The minimum measured diameter is 2.5 mm at the distance of aboutThe invasive irradiation temperature measurement was applied to trace the process of thermal interaction between lasers and bio-tissues. Portable Infrared thermal detector has inside LD red introductive light and can make a sound when aiming at an object. The minimum measured diameter is 2.5 mm at the distance of about 25 mm. The changes of the target's temperature rise are general reveal of both the laser parameters and the optical and thermal properties of the bio-tissue,which are closely relative to the final therapy effect. Experimental results included the real thermal responses of several tissues under single ruby laser pulse and CW CO2 laser. The thermal response difference was also discussed with variable duration time,temperature rise peak and rise time..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 265 (2006)
Theoretic Analysis and calculation on Optical-thermal Effect in PDT
Li Zhongming, and Zhang Zhenxi
Temperature distribution in the bio-tissue during PDT is theoretical analyzed based on the Pennes' bio-heat transfer equations. The study indicated that Laser heat source can be formed in bio-tissue during laser irradiation which result in temperature rising in one-dimensional space. The temperature in biological tTemperature distribution in the bio-tissue during PDT is theoretical analyzed based on the Pennes' bio-heat transfer equations. The study indicated that Laser heat source can be formed in bio-tissue during laser irradiation which result in temperature rising in one-dimensional space. The temperature in biological tissue increases in exponent with time and decreases in exponent with the distance from laser irradiation area. There is minimal light dosage threshold during the optical-thermal interaction between laser and biological tissue. When light dosage below the critical threshold,laser irradiating will not produce thermal effect. The threshold,which depends on optical parameter and heat parameter of biotissue,increases in exponent with the distance from laser irradiating area..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 269 (2006)
Analysis of Label Extraction with Semiconductor Optical Amplifier for Outical Networks
Niu Changliu, Zhang Min, and Ye Peida
In this paper,a novel scheme of header extraction for optical packet networks using only a semiconductor optical amplifier is proposed. Numerical analysis and simulation show,that more than 13 dB contrast ratio of the separated header at 2.5 Gb/s to the suppressed payload at 40 Gb/s could be achieved. In addition,the SIn this paper,a novel scheme of header extraction for optical packet networks using only a semiconductor optical amplifier is proposed. Numerical analysis and simulation show,that more than 13 dB contrast ratio of the separated header at 2.5 Gb/s to the suppressed payload at 40 Gb/s could be achieved. In addition,the SOA parameters are discussed and designed to optimize the performance of the proposed scheme..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 274 (2006)
Improvement on Statistic Model for PMD
Ding Panfeng, Sun Junqiang, and Hou Rui
Segment-dividing model is appropriate for research on PMD. Mathematical deduction is made to change it into iterative model. It is easy to find that the new model gives clear meaning in physics and reveals the process of PMD accumulation in fiber. It is applicable for being transplanted to analysis on PMD. Theoretic anSegment-dividing model is appropriate for research on PMD. Mathematical deduction is made to change it into iterative model. It is easy to find that the new model gives clear meaning in physics and reveals the process of PMD accumulation in fiber. It is applicable for being transplanted to analysis on PMD. Theoretic analysis gives the reason for error in Numerical calculation. The iterative method is put forward for practical numeration. It gives instruction for PMD compensation. Calculation is curtailed in the new model..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 277 (2006)
The Crosstalk Peculiarity of SOA Switch Gates In Optical Packet Switching
Ji Wei, Zhang Min, and Ye Peida
The crosstalk modeling of switching matrix based on the XGM in SOA for optical packetswitched networks is presented. Crosstalk-induced bit error rate (BER) and switch cascaded capability under unbalanced traffic are examined,which proves to be relevant to the SOA parameters,the traffic model unbalanced degree,the contrThe crosstalk modeling of switching matrix based on the XGM in SOA for optical packetswitched networks is presented. Crosstalk-induced bit error rate (BER) and switch cascaded capability under unbalanced traffic are examined,which proves to be relevant to the SOA parameters,the traffic model unbalanced degree,the control pulse energy and so on. Several rules are drawn to facilitate the design of SOA-based switching matrix under unbalanced traffic..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 281 (2006)
Tunable Transmittance of Defect Modes in One-dimensional Photonic Crystal with 3 Defects
Liu Dandong, Chen Guangde, Li Puxuan, and Sun Zhongyu
By propagation matrix method,the property of one-dimensional photonic crystals with 3 defects was analyzed. On condition that the distance between adjacent defects in the photonic crystals was long enough for a degenerate defect mode to be produced,transmittance of the degenerate defect mode can be tuned to the full exBy propagation matrix method,the property of one-dimensional photonic crystals with 3 defects was analyzed. On condition that the distance between adjacent defects in the photonic crystals was long enough for a degenerate defect mode to be produced,transmittance of the degenerate defect mode can be tuned to the full extent by a change of the optical path of one of defect layers in the photonic crystal. Nematic liquid crystal was introduced as one of the defect layers. As a result,the transmittance of the degenerate defect mode in the structure can be tuned by a change of the refractive index of the liquid crystal upon the application of an electric field. For the system,the maximum of transmittance was 1 and the minimum approachd 0,which were calculated by 4 × 4 propagation matrix. Possible applications of this system were discussed,especially in the field of communication where a optic switch can be produced..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 286 (2006)
Experiments of Point-projection Backlighting Using Pinholes
Jiang Shaoen, Huang Yixiang, Hu Xin, Yu Yanning, and Yu Ruizhen
X-ray backlighting is a powerful tool for diagnosing a large variety of high-density phenomena.In pinhole-assisted point-projection backlighting,pinholes are placed a small distance away from the backlighter source to produce images with large field of view. The techniques of point backlighting using pinhole was experiX-ray backlighting is a powerful tool for diagnosing a large variety of high-density phenomena.In pinhole-assisted point-projection backlighting,pinholes are placed a small distance away from the backlighter source to produce images with large field of view. The techniques of point backlighting using pinhole was experimentally demonstrated on Xingguang-Ⅱ facility (XG-Ⅱ) with 80 J,1 ns,351 nm laser pulse. The pinhole drilled on gold in diameter of 50 μm was irradiated by laser beam and pinhole closure was produced in order that x-ray pulse width was shortened,and then the function similar to point backlighting was obtained. The experimental results shown that the pinhole-assisted point-projection backlighting was feasible..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 290 (2006)
Applications of Two Types of Calibration Method to CCD Camera's Image Center Measurement
Wang Feng, Zhou Renkui, Yang Xiaoxu, Chen Min, Zou Yongxing, Luo Xiujuan, Cao Jianzhong, Zhou Sizhong, and Nie Haozhi
The practical applications of two types of calibration method to CCD camera's image center measurement were researched. With regard to image center,pixels' distribution on image plane is still symmetrical even under the influence of lens distortion. Based on this,in direct optical method,the image center is judThe practical applications of two types of calibration method to CCD camera's image center measurement were researched. With regard to image center,pixels' distribution on image plane is still symmetrical even under the influence of lens distortion. Based on this,in direct optical method,the image center is judged by the symmetry of pixels' position in vertical and horizontal directions on image plane. In lens distortion based perspective projection method,a complete imaging model could be constructed and image center is one of the parameters in the model. Two kinds of main lens distortion are considered in the model. Tests were done and the comparison was made for two methods. The second method's strong convergence property was confirmed..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 294 (2006)
General Theory Research on Morphological Correlation for Gray-Scale Face Recognition
Yu Yang, and Zhang Xuping
General morphological correlation (GMC) is proposed and hardware design for a compact joint transform correlator(JTC) is proposed in order to implement GMC. Two kinds of modified general morphological correlation is studied. The gray-scale image is decomposed into a set of binary image slices in certain decomposition mGeneral morphological correlation (GMC) is proposed and hardware design for a compact joint transform correlator(JTC) is proposed in order to implement GMC. Two kinds of modified general morphological correlation is studied. The gray-scale image is decomposed into a set of binary image slices in certain decomposition method. In the first algorithm,the edge of each binary joint image slice is detected and the joint power spectrum of which is summed. In the second algorithm,one situation is that the joint power spectrum of each pair is binarized or thinned and then summed,and another situation is that the summation of the joint power spectrums of these pairs is binarized or thinned. Computer-simulation results indicate that the modified algorithm can improve the discrimination capabilities with respect to the high similarity gray-scale face images..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 299 (2006)
A method of Complexion Detection based on SVM
Li Sumei, Zhang Yanxin, Dong Lei, Chang Shengjiang, and Shen Jinyuan
A detection method of complexion based on SVM is proposed in this paper. The technique is an approach for locating faces in a scene image based on the detection of skin color of an unspecific human which is essentially important in development of contact free human-machine-interaction (HMI) as well as in machine visionA detection method of complexion based on SVM is proposed in this paper. The technique is an approach for locating faces in a scene image based on the detection of skin color of an unspecific human which is essentially important in development of contact free human-machine-interaction (HMI) as well as in machine visions. The simulation results show that it may not only get better rate of correct recognition of complexion than that by using traditional artificial neural network but also is better in generalization.This is because that according the criteria of structural risk minimization of support vector machine(SVM),the errors between sample-data and model-data are minimized and the upper bound of predicting error of the model is also decreased simultaneously..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 304 (2006)
A Novel Image Retrieval Algorithm Based on Color and Distribution of Prominent Interest Points
Zeng Zhiyong, Zhang Xuejun, Cui Jiangtao, and Zhou Lihua
A novel algorithm for image retrieval based on prominent interest points is presented. The algorithm consists of three steps: prominent interest points detection,feature description based on prominent interest points and similarity measurement,image is filtered by a self-adaptive filter,then prominent interest points aA novel algorithm for image retrieval based on prominent interest points is presented. The algorithm consists of three steps: prominent interest points detection,feature description based on prominent interest points and similarity measurement,image is filtered by a self-adaptive filter,then prominent interest points are extracted;prominent interest points are regarded as clues,and annular color histogram is designed,which takes not only the local color feature into consideration but also the space distribution information of prominent interest points;the similarities are measured by the distance of annular color histograms. With robustness to rotation and translation,the algorithm avoids shortcoming of losing the location information in color histogram. Experimental results show that this algorithm is efficient for image retrieval..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 308 (2006)
An Approach of Extracting Reliable Feature Points for Image Matching
Jiao Yulong, Luo Xiujuan, and Ma Jiankang
An approach of extracting reliable feature points alone ridges/troughs is presented. The feature points including high curvature points along ridge/trough,cross points of ridges/troughs and minimum points in image surface. Experimental result shows that the approach is more robust as compare with the traditional approaAn approach of extracting reliable feature points alone ridges/troughs is presented. The feature points including high curvature points along ridge/trough,cross points of ridges/troughs and minimum points in image surface. Experimental result shows that the approach is more robust as compare with the traditional approach of extracting feature points along step edges and reduce the possibility of the appearance of outliers. Scanning the image for just one time will get the points along ridges/troughs,but computing the cross points of ridges/troughs and the high curvature points along ridge/trough will cost more time. So this approach is available for applications that require only a small set of highly reliable feature points..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 312 (2006)
RBF Neural Network Based Image Fusion Restoration Approach
Niu Lihong, Ni Guoqiang, and Su Binghua
A radial basis function (RBF)neural network based image fusion restoration approach for multiple spectrum images is proposed and investigated. The spatial resolution improvement of images with poor resolution can be achieved by fusing the images of various resolutions. The simulated experimental results show the effectA radial basis function (RBF)neural network based image fusion restoration approach for multiple spectrum images is proposed and investigated. The spatial resolution improvement of images with poor resolution can be achieved by fusing the images of various resolutions. The simulated experimental results show the effectiveness of the method. The image quality is improved by fusing the correlative and redundant information between images. The modified algorithms ensure quick training and mapping precision of the networks. The research also illustrates that using multi-channel information is more effective than using a single one and the scenario conducted has advantages over conventional methods..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 316 (2006)
Optoelectronics
Analysis and Simulation of Solar Cells' V-A Properties Based on P-N Junction
Ren Ju, Guo Wenge, and Zheng Jianbang
With the establishing of a mathematical model of P-N junction,the difference between a practical P-N junction and its ideal model was analyzed. The volt-ampere properties of diodes and solar cells were simulated through the model. The influence of series and shunt to open-circuit voltage and short-circuit current of soWith the establishing of a mathematical model of P-N junction,the difference between a practical P-N junction and its ideal model was analyzed. The volt-ampere properties of diodes and solar cells were simulated through the model. The influence of series and shunt to open-circuit voltage and short-circuit current of solar cells under certain illumination were demonstrated. With a simple model established by Matlab,the equivalent circuit of a solar cell was numerically analyzed and solved though a equation. At last,I-V properties of a Si solar cell were measured and compared to the I-V curve calculated by our model whose parameters were setting properly. The results show that the model established in this paper is consistent with the practical devices..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 171 (2006)
Study of the Phosphor Screen with the Transparent Conducting Film
Bai Xiaohong, Liu Jinyuan, Bai Yonglin, Liu Baiyu, Liu Xiuqin, and Wang Chen
A new type of phosphor screen is presented,in which the aluminum film is replaced by the transparent conducting film as electrode. When voltage is added in the electrode coated with transparent conducting film,the electric capability of this new type screen is much better than that used ones. And the X-ray imaging tubeA new type of phosphor screen is presented,in which the aluminum film is replaced by the transparent conducting film as electrode. When voltage is added in the electrode coated with transparent conducting film,the electric capability of this new type screen is much better than that used ones. And the X-ray imaging tube with this new type phosphor screen can obtain higher space resolution. Additionally,this technique also has some other virtues,such as more easier in operation,low cost and high rate of finished product..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 176 (2006)
Electron-Phonon Interaction on the Optical Kerr Effect in Cylindrical Quantum Wires
Guo Kangxian, and Chen Chuanyu
The optical Kerr effect in cylindrical quantum wires is investigated with density matrix approach,most emphasis is devoted to the electron-phonon interactions on the optical Kerr effect. With characteristic parameters pertaining to GaAs quantum wire,the numerical results are presented. It is shown that,the optical KerrThe optical Kerr effect in cylindrical quantum wires is investigated with density matrix approach,most emphasis is devoted to the electron-phonon interactions on the optical Kerr effect. With characteristic parameters pertaining to GaAs quantum wire,the numerical results are presented. It is shown that,the optical Kerr effect increases as the wire radius R0 decreases;the optical Kerr considering the electron-LO-phonon interactions is over twenty percent greater than the one without considering the electron-phonon interactions;the smaller the wire radius R0,the sharper the peak will be,and the larger the peak intensity will be;when the wire radius R0 is greater than 40 nm,the peak will disappear gradually..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 180 (2006)
Properties of Solar Cells Sensitized by Mixed Dye of Plant
Liu Baoqi, and Zhao Xiaopeng
The photochemical solar cells were prepared by mimicing photoelectrical conversion of photosynthesis using nanocrystalline mesoporous TiO2 film electrode,which were sensitized by single dye of chlorophyll and xanthophyll and the mixture of different concentration of them. The results of output properties test showed thThe photochemical solar cells were prepared by mimicing photoelectrical conversion of photosynthesis using nanocrystalline mesoporous TiO2 film electrode,which were sensitized by single dye of chlorophyll and xanthophyll and the mixture of different concentration of them. The results of output properties test showed that photoelectric conversion efficiency(η) of the cell sensitized by mixture of chlorophyll and xanthophyll were 5.8 times and 1.4 times as high as of which the cells sensitized by each single dye,the maximum output power(Wopt) was 5.7 times and 1.4 times of the cells sensitized by each single dye. The η and maximum Wopt exceeded linear superposition of the cells were sensitized by each single dye. This synergistic effect would be very important to improve η of the cells and obtain cheap and clean energy with great efficiency..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 35, Issue 2, 184 (2006)
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