Journals >Acta Photonica Sinica
Contents
2014
Volume: 43 Issue 6
37 Article(s)
Export citation format
Research Article
Simulation of Atmospheric Radiative Properties at IR Bands under Water Clouds Based on MODIS Data
CAO Yanan, WEI Heli, XU Qingshan, DAI Congming, and CHEN Xiuhong
The combined atmospheric radiative transfer model based on MODIS level2 cloud products and atmospheric products was used to simulate brightness temperature at the top of atmosphere with water clouds at 8.55 μm, 11.03 μm and 12.02 μm bands. The brightness temperatures between model and MODIS observation at 8.55 μm,11.03The combined atmospheric radiative transfer model based on MODIS level2 cloud products and atmospheric products was used to simulate brightness temperature at the top of atmosphere with water clouds at 8.55 μm, 11.03 μm and 12.02 μm bands. The brightness temperatures between model and MODIS observation at 8.55 μm,11.03 μm and 12.02 μm bands were compared and analyzed . Results show that brightness temperature simulated by Combined Atmospheric Radiative Transfer model based on satellite cloud parameters, atmosphere parameters and space geometric parameters is basically consistent with MODIS observation. The brightness temperature difference between them is quite small. And brightness temperature difference between model and MODIS is mostly at the range of －10 K~10 K. Varieties of brightness temperature BTD(8.55~11.03 μm) and BTD(11.03~12.02 μm) of model were accordant with conditions under water clouds..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 601001 (2014)
Laboratory Simulation of Atmosphere Turbulence for Fourier Telescopy
ZENG Zhihong, LUO Xiujuan, WANG Baofeng, XIA Aili, CHENG Zhiyuan, and SI Qingdan
Fourier telescopy is a sort of highresolution imaging technology for deep space object which is very small and dim. To verify the atmosphere turbulence net effect on Fourier telescope, the experimental demonstrations of atmosphere turbulence simulation were performed in a lab. Based on the laboratory system of threebFourier telescopy is a sort of highresolution imaging technology for deep space object which is very small and dim. To verify the atmosphere turbulence net effect on Fourier telescope, the experimental demonstrations of atmosphere turbulence simulation were performed in a lab. Based on the laboratory system of threebeam Fourier telescope, the scintillation and the phase jitter were simulated by changing the radiofrequency driver output power and the instantaneous frequency, respectively. The detail of the experimental principle was presented, and the relation between the turbulent intensity and experimental variable was built. For different cases with random scintillation and phase jitter in weak turbulence, the experiments were conducted for single beam and three beams, and all the results’ Strehl ratio were calculated. The experimental results indicate that, with single beam holding turbulence, there are no obvious change for all the reconstructed image; with three beams adding turbulence, the image quality of the Fourier telescope system is few influenced by weak scintillation, but is severe affected by phase jitter. As indicated, removing the phase and light intensity jitter effect is a key point of improving the image reconstruction arithmetic..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 601002 (2014)
Determination of Azimuth Angle of Photonic Crystal Fiber by Characteristic Analysis of Side Transmission Images
CHEN Zhe, XIE Junxin, LUO Yunhan, TANG Jieyuan, HUANG Huacai, YU Xinyu, GAN Hongbo, MA Yue, WEI Qingsong, YU Jianhui, ZHANG Jun, LU Huihui, and PENG Jinggang
Determination of azimuth angle of photonic crystal fiber is essential in the fabrication of devices based on photonic crystal fiber. The side images of hexagonal、hybrid and large mode area20 structures of photonic crystal fibers were studied by illuminating the side of photonic crystal fibers vertically. The side imagDetermination of azimuth angle of photonic crystal fiber is essential in the fabrication of devices based on photonic crystal fiber. The side images of hexagonal、hybrid and large mode area20 structures of photonic crystal fibers were studied by illuminating the side of photonic crystal fibers vertically. The side images vary with the rotation of the fibers, and they display special light intensity characteristics. The characteristic values of images show periodic variation, which is corresponding with the inner structure of photonic crystal fibers. Simulation analysis for photonic crystal fibers were made by Tracepro software, the results of simulation show that the characteristic values of side images change with the rotation of fiber, and they perform the similar features with the experimental research. Compared with the characteristic curve of the experimental and the simulation results, the characteristic values has maxima values around the vertex direction of hexagonal structure formed by air holes, and it can be used to distinguish azimuth angle of photonic crystal fibers..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 606001 (2014)
Low Loss and High Birefringence Topas Photonic Bandgap Fiber at Terahertz Frequency
WANG Doudou, WANG Lili, ZHANG Tao, and XIE You
A photonic bandgap fiber was designed based on the novel Terahertz lowloss material Topas cyclic olefin copolymer. Fiber cladding was formed by arranging hexagonal air holes with rounded corners in triangular lattice pattern in the background of Topas. A rhombic hollowcore with rounded corners was formed by omitting A photonic bandgap fiber was designed based on the novel Terahertz lowloss material Topas cyclic olefin copolymer. Fiber cladding was formed by arranging hexagonal air holes with rounded corners in triangular lattice pattern in the background of Topas. A rhombic hollowcore with rounded corners was formed by omitting four central air holes of the cladding structure. Propagation properties in the terahertz band of the fiber were investigated by using the finite element method. Numerical results indicate the fiber has a photonic bandgap within a broadband area about 0.3 THz around 1.5 THz, and THz wave is welled confined in the air core. Birefringence of the order of 10－3 was obtained. Loss of the xand ypolarized fundamental modes is less than 0.1 cm－1 within 1.4~1.6 THz, and reaches the minimum value of 0.029 1 cm－1 and 0.028 7 cm－1 at 1.53 THz and 1.5 THz, respectively. Structure of designed terahertz Topas photonic bandgap fiber is simple, feasible for fabrication and bendable because of the relatively small diameter..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 606002 (2014)
3~5 Microns Chalcogenide Photonic Crystal Fiber with Broadband Ultra low Flattened Dispersion
CAO Fengzhen, ZHANG Peiqing, DAI Shixun, WANG Xunsi, XU Tiefeng, and NIE Qiuhua
Using the dispersion controlled feature of chalcogenide photonic crystal fiber, the broadband ultralow dispersionflattened chalcogenide photonic crystal fibers was designed, and the multipole method was used to research the effects of the hole pitch and the aperture ratio on the dispersion curves. By optimizing the diUsing the dispersion controlled feature of chalcogenide photonic crystal fiber, the broadband ultralow dispersionflattened chalcogenide photonic crystal fibers was designed, and the multipole method was used to research the effects of the hole pitch and the aperture ratio on the dispersion curves. By optimizing the diameter of the air holes of different layers in cladding, the structure with 0.7 μm air hole radius of inside two layers, 0.8 μm air hole radius of outer two layers and 5 μm hole pitch were obtained. The simulation results show that this structure is broadband flattened dispersion in 3~5 μm, and the absolute value of dispersion is less than 3.8 ps·nm－1·km－1..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 606003 (2014)
Fiber Bragg Grating Wavelength Shift Measurement Method Based on Cross spectrum Detection and Crosscorrelation Technology
LI Zhizhong, XU Zhongliang, LI Haitao, CHENG Yusheng, and SHI Qiuliang
In order to improve the accuracy of wavelength shift measurement which is limited by the scanning wavelength step in the traditional measurement, a method which combinates a coarse measurement and a fine one was present based on the crossspectrum detection and crosscorrelation technology. The coarse wavelength shift In order to improve the accuracy of wavelength shift measurement which is limited by the scanning wavelength step in the traditional measurement, a method which combinates a coarse measurement and a fine one was present based on the crossspectrum detection and crosscorrelation technology. The coarse wavelength shift measurement which is based on the principle of crosscorrelation detection has achieved a wide range of measurement, and the fine wavelength shift mesurement which is based on the principle of crossspectrum detection has achieved a highprecision measurement. Both the range and the precision are improved with the combination of the coarse and the fine measrurement. The smoothing tecnlogy is applied for data processing, which has eliminated the influence of random noise in the detection system. The fiber grating wavelength shift is measured directly to reduce the system error which has avoided the measurement of the absolute values of FBG center wavelength. Simulation results show that the method breaks the limit of the scanning wavelength step, and the measurement accuracy is improved about three orders. FBG longitudinal load measuring experiment with the load range of 0~60 g was carried out and the new method was applied to process the experiment data, the results show that the FBG longitudinal load sensitivy is 13.2 pm/g, the new method has a better applicability..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 606004 (2014)
Medianbased Square Distance Symmetrical Cooccurrence Matrix Thresholding Method
ZHANG Hong, and FAN Jiulun
The image threshold selection of skew and heavytailed classconditional distributions were studied. Due to the deviation of the meanbased method in classification estimation, the medianbased method is more reasonable in threshold selection. Based on the square distance symmetrical cooccurrence matrix, the region meThe image threshold selection of skew and heavytailed classconditional distributions were studied. Due to the deviation of the meanbased method in classification estimation, the medianbased method is more reasonable in threshold selection. Based on the square distance symmetrical cooccurrence matrix, the region median was defined, and then using median classified statistics method, a new threshold approach was proposed based on the square distance symmetrical cooccurrence matrix, and the multithreshold segmentation algorithms was advanced. Compared with Otsu′s and square distance, the proposed method not only has prominent segmentation performance for the images of skew and heavytailed classconditional distributions, but it takes the more spatial statistical information on account, compared with medianbased Otsu′s thresholding, the extracted object information is more complete, and the edge is clearer. For the small object probability distribution images, this method also has better threshold segmentation effect. To illustrate the correctness and effectiveness, based on the groundtruth images, the misclassification error results show that the proposed method can obtain the minimum value..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 610001 (2014)
Imaging of Fluttering Target Based on Complexvalued Empiricalmode Decomposition Algorithm
XU Yimeng, GUAN Hua, WANG Guozheng, LUO Ying, and ZHANG Qun
In the process of inverse synthetic aperture radar imaging with the millimeter wave radar, the microDoppler effect caused by extensive fluttering in the target′s body may introduce interference into imaging. To solve this problem, an inverse synthetic aperture radar imaging model of a fluttering target was establishedIn the process of inverse synthetic aperture radar imaging with the millimeter wave radar, the microDoppler effect caused by extensive fluttering in the target′s body may introduce interference into imaging. To solve this problem, an inverse synthetic aperture radar imaging model of a fluttering target was established, the effect on the imaging made by fluttering was analyzed. A novel inverse synthetic aperture radar imaging method for fluttering target was proposed, based on complexvalued empiricalmode decomposition algorithm. Firstly, taking advantage of the adaptivity of complexvalued empiricalmode decomposition, the target echo signal was decomposed into component signals of different frequency; then the concept of complexity was used to distinguish the component signals; finally the micro motion signal component was excluded according to comparison of all components′ energy percentage, and the microDoppler effect can be eliminated effectively. Using the combination of the concept of the complexity and the energy percentage, this method can improve the imaging precision. Simulations show the effectiveness of the proposed method..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 610002 (2014)
Surface Plasmon Resonance Imaging Based on Slit Scanning
GAO Laixu, LI Songquan, YE Hongan, LIU Shugang, JIANG Shihong, LIU Chunyu, and AN Xu
The surface plasmon resonance technique was used for imaging of the dielectric sample. Based on a large numerical aperture microscope objective configuration, a light beam from a HeNe laser (λ=632.8 nm) was converged to excite surface plasmon resonance on gold film. The image of Si3N4 grating on the gold film was acquThe surface plasmon resonance technique was used for imaging of the dielectric sample. Based on a large numerical aperture microscope objective configuration, a light beam from a HeNe laser (λ=632.8 nm) was converged to excite surface plasmon resonance on gold film. The image of Si3N4 grating on the gold film was acquired by using a slit which restricts the incident angle of imaging beam. CCD was placed to detect the reflected light and get the surface plasmon resonance image of the sample at the conjugate plane of the sample. The images of sample was obtained at incident angles from 44° to 54° via scaning of the slit. The surface plasmon resonance curves of each point of the sample was extracted from this set of images. Grayscale image of resonance angular spectra of sample was reconstructed by computer simultaneously using the resonance angles corresponding to each point of sample..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 611001 (2014)
The Design and Realization of Dynamically Stabilizing Retinal Image in Human Eye Aberration Wavefront Correction Setup
LI Pengfei, XU Jinkai, HAN Wenbo, and SONG Hongfei
The unconsciousshake of human eye leads to the random variations of image position, and makes it impossible to observe a specific area. To solve the problem, during the object imaging, a real time “calculationmovement”stabilizing image algorithm was presented based on image matching theory. It uses a series of continuThe unconsciousshake of human eye leads to the random variations of image position, and makes it impossible to observe a specific area. To solve the problem, during the object imaging, a real time “calculationmovement”stabilizing image algorithm was presented based on image matching theory. It uses a series of continuously grabbed images that focus on nearly the same area of retina. Therefore, it is possible to find the center area of the image through “samplingcalculaiton”, and do the correlation between the center area and that of the first image so as to get the direction and amplitude of movement, finally move the picture according the results. Repeat this process to stabilize the series of images and remove those unmatched images, which make the object image nearly on the same position. The results indicates that the algorithm can overcome the random variation problem of object image position and stabilize the retinal image in real time for the adaptive optics imaging setup; overcome the problem that one cannot focus on the same area for a long time because of laser′s strongly irritation, and realize the retina and blood capillary observation with the same setup and same algorithm; make it possible to get anpatched image with large field of view..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 611002 (2014)
Digital Holographic Video Imaging Technology and its Application in Liver Fluke Cercariae Observation
WANG Fengpeng, LI Yibao, ZHEN Xiangzhi, and WANG Xinquan
The traditional microscope is not suitable to observe the liver fluke cercariae moves in water, because it needs an optical focusing process. A continuous dynamic observation method for liver fluke cercariae based on digital inline holographic video was proposed. The dynamic tracking focus and video processing algoritThe traditional microscope is not suitable to observe the liver fluke cercariae moves in water, because it needs an optical focusing process. A continuous dynamic observation method for liver fluke cercariae based on digital inline holographic video was proposed. The dynamic tracking focus and video processing algorithms were studied. The center of the liver fluke cercariae in the reconstructed image was used as the center of focusing window in the reconstructing for next frame of holographic video, so the focusing window followed the liver fluke cercariae all the time. Thus ensuring each frame of reconstructed video was in focused accurately, so that the liver fluke cercariae in the video was always in a clear state. The observation of liver fluke cercariae experiment was carried out. The holographic reconstructed video of liver fluke cercariae swiming in the water was obtained. The liver fluke cercariae law of motion was summed up by tracked it’s trajectory in the water. The experimental results show that capture a digital hologram can observed fluke cercariae at different positions in water use the digital holography technology, which makes detection more convenient and efficient, and the proposed digital holographic video imaging technology can achieve the continuous dynamic observation of the liver fluke cercariae or other plankton in water..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 611003 (2014)
A Rapid Position Estimation Algorithm Inspired of Compound Eyes
XING Qiang, DAI Zhendong, and WANG Hao
Compound eye consistis of thousands of ommaditia, which insures the ability of fast detection and location on obstacles and predators. Inspired of compound eye, a method of fast location estimation was proposed. Firstly, a parametric equation between space and detectors field of view was established including unknown pCompound eye consistis of thousands of ommaditia, which insures the ability of fast detection and location on obstacles and predators. Inspired of compound eye, a method of fast location estimation was proposed. Firstly, a parametric equation between space and detectors field of view was established including unknown parameters, which can be gotten from the array of detecters detected moving targets; secondly, detectors in line array were used to get moving objects signals by simulation; finally, analys the signal data with threshold to form the array of detectors′, which was used to solve parametric equation and achieve positioning. Compared with the result betwen actual distance and the calculated, the results show the method can achieve the target location estimation of different sizes in different trajectories in time..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 612001 (2014)
A Method for ShenguangⅢ Diagnostic Instrument Manipulator High Precision Automatic Aiming
WANG Wei, WANG Zhengzhou, HE Junhua, ZHANG Min, WEI Mingzhi, and YAN Yadong
In order to realize diagnostic instrument manipulator precise targeting, an aiming method based on visual servoing was proposed. Defined the target deviation and projection matrix in the vision system, the calculated target deviation value computed by projection matrix was closed to the true value. Using a 3DOF hybridIn order to realize diagnostic instrument manipulator precise targeting, an aiming method based on visual servoing was proposed. Defined the target deviation and projection matrix in the vision system, the calculated target deviation value computed by projection matrix was closed to the true value. Using a 3DOF hybrid mechanism motion mode, the motion accuracy was promoted. With optimizing visual servoing strategy based on projection matrix and motion mode, the total targeting work was greatly simplified, making the vision system calibration unnecessary. Automatic positioning tests indicate that pointing accuracy is 11μm in X direction and 12 μm in Y direction. Radical positioning accuracy is 14 μm.Laser shot tests with streak camera show that the automatic aiming method can satisfy the requirements of project..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 612002 (2014)
Numerical Simulation of Transient Response Process of L2 Aluminum Sheet by Laser Loading Highspeed Forming
YAO Hongbing, YU Wenlong, GAO Yuan, LI Yaru, MENG Chunmei, JIANG Guangping, and ZHANG Yongkang
The highspeed forming process of L2 aluminum sheet by laser loading was numerically simulated with the finite element software ABAQUS. In the simulation, the transient response process of the forming by single laser loading was investigated, and the change rules of the characteristics, such as displacement, velocity, The highspeed forming process of L2 aluminum sheet by laser loading was numerically simulated with the finite element software ABAQUS. In the simulation, the transient response process of the forming by single laser loading was investigated, and the change rules of the characteristics, such as displacement, velocity, strain and strain rate, were discussed. The results indicated that an obvious plastic deformation occurred in the central part of the target after the laser loading, and the cross sections thereof were conical. During the process of highspeed forming, the metal sheet underwent a rapid elastic deformation with large oscillation amplitude, and then attenuated into a static state. In the laser forming, the deformation duration was usually at a level of a few microseconds. The displacements at the different nodes varied in a similar trend, among which those in the central region endured larger variations than those in the boundary region. The maximum speed in the central region of the aluminum sheet reach 3 700 m/s during the laser forming. The strain rate increased considerably in the period of 2 μs during the forming, whose maximum value is at a level of 104~105 s－1..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 614001 (2014)
Tunable Multiwavelength Brillouin Erdoped Fiber Laser with 0.173 nm Spacing
ZHANG Peng, JIA Qingsong, WANG Tianshu, and JIANG Huilin
A tunable multiwavelength brillouin/erbium fiber laser with doubleBrillouinfrequency spacing based on a fourport circulator was experimentally demonstrated. The fiber laser configuration formed by fourport circulator isolates the oddorder brillouin stokes signal to circulate within the cavity only. In addition, itA tunable multiwavelength brillouin/erbium fiber laser with doubleBrillouinfrequency spacing based on a fourport circulator was experimentally demonstrated. The fiber laser configuration formed by fourport circulator isolates the oddorder brillouin stokes signal to circulate within the cavity only. In addition, it also allows propagation of the incoming brillouin pump and evenorder Stokes signals from fourport circulator to output coupler. A fiber FabryPerot tunable filter was used to manipulate the location of selflasing cavity and to increase power for multiwavelength oscillation. It can be obtained that a wideband tuning range and more output channels. At the brillouin pump power of 8 dBm and the 980 nm pump power of 279 mW, 6 output channels with 0.173 nm spacing and tuning range of 28 nm from 1535 nm to 1563 nm were achieved..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 614002 (2014)
A Temperature Controller for Nearinfrared Semiconductor Laser Used in Gas Detection
HUANG Jianqiang, ZHAI Bing, HE Qixin, YE Weilin, ZHENG Chuantao, and WANG Yiding
In order to decrease the design complexity of software and to enhance the control stability and accuracy of distributed feedback laser′s emitting wavelength, a temperature controller for semiconductor laser used in gas detection was developed, which includes digital signal processor, temperature setting circuit, temperIn order to decrease the design complexity of software and to enhance the control stability and accuracy of distributed feedback laser′s emitting wavelength, a temperature controller for semiconductor laser used in gas detection was developed, which includes digital signal processor, temperature setting circuit, temperature sampling circuit, analog proportionintegrationdifferential circuit, thermal electric colling control circuit, etc. A wavelengthtunable distributed feedback laser centered at 1 860 nm used for humidity detection was driven using the proposed temperature controller. Experimental results indicate that, the control scale on temperature is 10 ℃~50 ℃, the accuracy is ±0.05 ℃, and the temperatureestablished time is less than 60 s; with different driving current and temperature supplied by the system, the operation wavelength of the laser shows good tuning characteristics; the four spectral curves from four days′ measurements almost coincide with each other, demonstrating stable performances of the controller..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 614003 (2014)
Laser doped Selective Emitter of Polycrystalline Silicon Solar Cell
WANG Xue, DOU Weijiang, QIN Yingxiong, and JU Xiaobao
The matching property of polycrystalline wafers phosphorus diffusion and laser doping process was studied. Nanosecond pulsed laser with a wavelength of 532 nm was used to conduct laser scanning doping on polycrystalline wafers which remains phosphorosilicate glass after diffusion. The sheet resistance decreases about 5The matching property of polycrystalline wafers phosphorus diffusion and laser doping process was studied. Nanosecond pulsed laser with a wavelength of 532 nm was used to conduct laser scanning doping on polycrystalline wafers which remains phosphorosilicate glass after diffusion. The sheet resistance decreases about 50%, and with the increasing of laser power, more phosphorus atoms diffuse to polycrystalline silicon, and the sheet resistance decreases more significantly. The external quantum efficiency of the conventional solar cells and laserdoped solar cells was tested, and for the band of 340~480 nm, the EQE of laserdoped cells increased by 18% to 5% compared to the conventional solar cells. The photoelectric conversion characteristics of laserdoped polycrystalline silicon cells were studied, and the failure characteristics under high laser power were analyzed. With the using of optimization of laser doping polycrystalline silicon solar cell process technology, the average photoelectric conversion efficiency of solar cells achieves 17.11%, which is 0.34% higher than that of the conventional cells. The highest efficiency achieves 17.47%. Laser doping process is simple, and conversion efficiency increases significantly, so this process makes it easy to realize industrialization..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 614004 (2014)
Novel Ge-Ga-Te-KBr Far InfraredTransmitting Chalcogenide Glasses System
ZHU Minming, WANG Xunsi, XU Huijuan, NIE Qiuhua, JIANG Chen, ZHANG Peiquan, DAI Shixun, SHEN Xiang, XU Tiefeng, and XianghuaZhang
A series of (Ge15Ga10Te75)100x(KBr)x (x=2, 4, 6, 8 mol%) far infrared transmitting chalcogenide glasses was prepared by the traditional meltquenching method. Some instruments of Xray diffraction, differential scanning calorimeter were adopted to test the structure and physicochemical properties of the glasses. At thA series of (Ge15Ga10Te75)100x(KBr)x (x=2, 4, 6, 8 mol%) far infrared transmitting chalcogenide glasses was prepared by the traditional meltquenching method. Some instruments of Xray diffraction, differential scanning calorimeter were adopted to test the structure and physicochemical properties of the glasses. At the same time, the effects of KBr to GeGaTe glasses on glass forming, net structure and thermal stability, UVVis absorption and FTIR spectrometer were adopted to study the optical properties of the glasses with the dopant of KBr. The Tauc equation was adopted to calculate the direct and indirect optical band gaps of the bulk glasses. The results show that a redshift appears in the absorbing cutoff edge of shortwave in the glasses, cutoff edge of longwave IR just keeps the same regardless of the increase of KBr content. The group of glasses can keep the superiorities of stable and wide infrared transmission..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 616001 (2014)
Judd Ofelt Theory Analysis and Spectroscopic Properties of Nd3+-doped TeO2-Al2O3-Cs2O Tellurite Glasses
QIN Zhongxue, YUAN Xiao, XIONG Baoxing, ZOU Kuaisheng, ZHANG Xiang, and ZHANG Guiju
A kind of tellurite glasses with the composition of 80TeO210Al2O310Cs2OxNd2O3 (x=0,0.5,1.0) (mol%) were fabricated by the conventional meltquenching method. The index of refraction of the glass was measured. The absorption apectra, fluorecence spectra and fluerecence decay cures of Nd3+in the glass were recorded. AA kind of tellurite glasses with the composition of 80TeO210Al2O310Cs2OxNd2O3 (x=0,0.5,1.0) (mol%) were fabricated by the conventional meltquenching method. The index of refraction of the glass was measured. The absorption apectra, fluorecence spectra and fluerecence decay cures of Nd3+in the glass were recorded. A JuddOfelt theory analysis was made based on the absorption spectrum for each Nd3+doped tellurite glass. The three JuddOfelt intensity parameters Ωλ(λ=2,4,6) for Nd3+ in TeO2Al2O3Cs2O glass were obtained form the absorptive spectrum and an fluorescence effective linewidth Δλeff , radiative transition probabilities AJ for emission from 4F3/2 to the 4IJ (J=9/2, 11/2, 13/2, 15/2) manifolds, luminescence branching ratios β, corresponding radiative lifetime τrad and quantum efficiency η, the stimulated emission cross section for the 4F3/2→4I11/2 transition σemi as well.The TeO2Al2O3Cs2O tellurite glass doped with 0.5mol% Nd3+ possesses a good effective linewidth of 31.4nm, a high quantum efficiency of 89% and a large value of σemi·τmeas up to 6.21×10－24cm2·s for the transition from 4F3/2 to 4I11/2. Spectrum analysis results indicate that, the Nd3+doped TeO2Al2O3Cs2O tellurite glass is a kind of solid laser material with excellent performance..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 616002 (2014)
Bandgap Characteristics of Twodimensional Archimedes (4,82)Compound Lattice Photonic Cystals with Dielectric Rods
HAN Changsheng, YANG Yibiao, WANG Yuncai, FEI Hongming, CHEN Zhihui, and LI Xiangxia
The bandgaps of the twodimensional Archimedes (4,82) lattice consisting of different dielectric circular and square rods were calculated with the plane wave expansion method. The bandgaps of the lattice with dielectric rods were investigated as the refractive index, dielectric rods shape, filling fraction and rotationThe bandgaps of the twodimensional Archimedes (4,82) lattice consisting of different dielectric circular and square rods were calculated with the plane wave expansion method. The bandgaps of the lattice with dielectric rods were investigated as the refractive index, dielectric rods shape, filling fraction and rotational symmetry changing. It was found that the width of the complete photonic bandgaps is not always increasing with the difference of the refractive index. The widest complete photonic bandgaps could be achieved in the (4,82) structure when the refractive index is between 2.60 and 5.40. For the Archimedes (4,82) lattice of circular dielectric rod, the width of complete bandgap reaches the maximum when the dielectric refractive index of rod is equal to 2.80. Also, the complete bandgap of square dielectric rod reaches the maximum when the dielectric refractive index equals 2.80 and 4.40. In addition, the rotation angle of square dielectric rods can significantly increase the width of complete bandgap. The results demonstrate that the quantity, width and frequency position of bandgaps can be modulated by changing the refractive index, the filling fraction and other structural parameters..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 616003 (2014)
Strain Distribution of Metal Nanoparticles Embedded in Lu2O3 Film
LIU Xiaoshan, YUAN Cailei, LIU Guiqiang, FU Guolan, and LUO Xingfang
The strain distributions of Au, Cu, Pt and Co nanoparticles embedded in Lu2O3 matrix were investigated by the finiteelement calculations. The simulation results indicated that all of metal nanoparticles incure compressive stress by the Lu2O3 matrix, which thus result in the corresponding strain in the center and at thThe strain distributions of Au, Cu, Pt and Co nanoparticles embedded in Lu2O3 matrix were investigated by the finiteelement calculations. The simulation results indicated that all of metal nanoparticles incure compressive stress by the Lu2O3 matrix, which thus result in the corresponding strain in the center and at the surface of nanoparticles. The strain distributions are closely related to the Young's modulus and poisson's ratio of metal nanoparticles and matrix. For the metal nanoparticle with bigger Young′s modulus,the difference between the strain in the center and that at the surface of the nanoparticles is largerer. While, for the metal nanoparticle with smaller Young's modulus, the difference between the strainat the surface and that in the center of the nanoparticles is smaller. Meanwhile, with the growth of metal nanoparticles, the deviator strain also increase. This net deviatoric strain distribution may also have a significant influence on the morphology and microstructure of metalnanoparticles, and thus the physical properties of metal nanoparticles..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 616004 (2014)
The Preparation and Stability Study of Silver Triangle Nanoparticle
FENG Xuehong, FENG Xuanqi, HUANG Liqing, XU Zhongfeng, WANG Jun, ZHANGWeiwei, LIU You, LI Xin, CHENG Long, YE HongGang, ZHAI Lipeng, SHAN dongzhi, and GAO Meng
Silver triangular nanoparticles were prepared by irradiating silver seed colloid with controlled PH at room temperature. The surface enhanced Raman activity and the time stability of asprepared silver triangular nanoparticles were investigated by experiments. The comparative analysis results of transmission electron mSilver triangular nanoparticles were prepared by irradiating silver seed colloid with controlled PH at room temperature. The surface enhanced Raman activity and the time stability of asprepared silver triangular nanoparticles were investigated by experiments. The comparative analysis results of transmission electron microscopy images, UVvisible spectroscopy and Surface Enhanced Raman Scattering (SERS) spectroscopy of asprepared sample and sample deposited for 5 months in dark room at room temperature show that the geometric shape, size and maximum absorption wavelength of deposited sample are essentially unchanged, which indicate that asprepared silver triangular nanoparticles have better time stability. And the deposited sample exhibits strong SERS activity for rhodamine 6G molecules..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 616005 (2014)
Holographic Properties of Modified and Unmodified Fe3O4nanoparticle Dispersed Acrylate Photopolymer
LI Chunliu, LI Yunxi, XUE Xiaoyu, WEI Qiaonan, NIE Huili, ZHU Zhiguang, and HUANG Mingju
Holographic recording characteristics of the unmodified and modified by sodium citrate Fe3O4nanoparticles dispersed in conventional organic photopolymers were studied. The hybrid photopolymer exist the mutual diffusion process and antiwrinkle effect in the experimental system was verified. The results of the experimeHolographic recording characteristics of the unmodified and modified by sodium citrate Fe3O4nanoparticles dispersed in conventional organic photopolymers were studied. The hybrid photopolymer exist the mutual diffusion process and antiwrinkle effect in the experimental system was verified. The results of the experiment show that the incorporation of the both two kinds of Fe3O4nanoparticle leads to an improvement of the holographic performance, but the incorporation of the modified Fe3O4nanoparticle shows a higher holographic performance. The maximum diffraction efficiency reach to 90%, the maximum refractive index modulation arrives at 2.14×103, and the volume shrinkage reduces to 0.8%. All of the results demonstrate that the incorporation of modified Fe3O4nanoparticle is more conductive to improving photopolymer holographic performance..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 616006 (2014)
Optimization of Optical Systems with the Realcoded Genetic Algorithm Incorporated into Escape Function
WANG Zemin, and LU Lijun
To reach the optimal design of optical system, the binary coding of standard genetic algorithm was changed to real coding to improve its robustness and calculation efficiency, and an escape function was incorporated into the evaluation function of system to avoid falling into local minima. Then the improved genetic algTo reach the optimal design of optical system, the binary coding of standard genetic algorithm was changed to real coding to improve its robustness and calculation efficiency, and an escape function was incorporated into the evaluation function of system to avoid falling into local minima. Then the improved genetic algorithm was applied to optimize a fisheye lens and a catadioptric panoramic image system. The imaging performances were simulated by raytracing calculation with Zemax and optimized with CODE V for comparison. The calculation results show that the optical system optimized with the improved algorithm has better imaging performance than which optimized with standard genetic algorithm mixed with escape function or optimized by CODE V. The study confirms that the proposed algorithm has satisfactory robustness and calculation efficiency in optimization of optical systems..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 622001 (2014)
Optomechanical Design of Beam Expander on Laser Jamming System
HE Binggao, AN Zhiyong, CAO Miao, and CAO Weiguo
In view of the actual problems existed in the routine infrared jamming technology, such as failure to meet required energy concentration, poor concealment and unable to be realized zoom, a design scheme regarding a new offaxis double mirror type of laser jamming applied at beam expander was put forward. The opticalmeIn view of the actual problems existed in the routine infrared jamming technology, such as failure to meet required energy concentration, poor concealment and unable to be realized zoom, a design scheme regarding a new offaxis double mirror type of laser jamming applied at beam expander was put forward. The opticalmechanical structures of such key components as the battery of offaxis double mirrors, the steering mirror and supporting and fixing mechanisms, etc. were designed and analyzed. A newstyle structural design of offaxis was adopted, realizing zoom function of the expansion ratio; the design of microstress was adopted for components of both the main and secondary mirrors and the components of steering mirror. Analysis results show that the first order natural frequency is 108.3 Hz, and stress responses of the structure is also smaller than yield limit of the material; in the temperature range of －20℃ to +60℃, the maximum displacement of the main and secondary mirrors is below or equal to 0.01mm and the surface accuracy is below to 71.9 nm. After the actual detection, the beam expanding ratio obtained is 1:10.02(19.92, 25.02), meeting the requirement of designed technical index. Analysis and experimental results demonstrate that designs of the optical and mechanical structure are effective that can meet the requirements of actual applications..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 622002 (2014)
Design, Measurement and Alignment of a Coude Optical System with Reimaging
MING Ming, Lv Tianyu, and WU Xiaoxia
A 1.23 m aperture optical telescope and its Coude optical system were introduced. Compared several forms of Coude optical systems with internal and overseas groundbased telescope, a kind of optical system was designed that used offaxis elliptical mirror as reimaging element. Then the corresponding measurement and aliA 1.23 m aperture optical telescope and its Coude optical system were introduced. Compared several forms of Coude optical systems with internal and overseas groundbased telescope, a kind of optical system was designed that used offaxis elliptical mirror as reimaging element. Then the corresponding measurement and alignment methods of optical system were obtained. After actual measurement and alignment, the wavefront errors among three processes (designed errors, test error and alignment errors) were compared and analyzed, which proved that the method of measurement and alignment were reliable and advanced. The focal length of Coude optical system is 125 meters, field of view is 1.5′, the band of wavelength is between 0.4~5 μm, and the designed RMS wavefront error is less than λ/50(λ=0.632 8 μm). The RMS wavefront error that measured in the room is less than λ/20. The telescope was used to observe fixed star, the wavefront was tested with ShackHartmann wavefront sensor, and the whole Coude optical system RMS wavefront error of less than λ/4 was obtained..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 622003 (2014)
Design of Large Aperture Offaxis Middle Infrared Continuous Zoom Lens
WANG Dabao, JIANG Kai, ZHAO Shimin, HAO Wei, JIANG Bo, and ZHOU Sizhong
On the basics of a cool 320×240 detector with staring focal plane array, a offaxis catadioptric middle infrared continuous zoom system with large aperture and long focal length is designed. The optical system was divided into two segments. First an offaxis aspheric nonpower system as the front system was designOn the basics of a cool 320×240 detector with staring focal plane array, a offaxis catadioptric middle infrared continuous zoom system with large aperture and long focal length is designed. The optical system was divided into two segments. First an offaxis aspheric nonpower system as the front system was designed, then the continuous zoom lens which matched with the nonpower system as the back system was designed. Because of the material constraint, the refractive zoom system can′t realize large aperture. Coaxal catadioptric zoom system has great block ratio. And three mirrors zoom system can′t achieve cold shield efficiency 100%. The offaxis catadioptric zoom system can account for forenamed limitation. The system worked at 3.7～4.8 μm has achieved the zoom of 250 mm to 2 000 mm and F number of 4. This system can offer a high resolution and excellent images, and its cold shield efficiency is 100%. The system satisfies the design requirements..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 622004 (2014)
Calibration Approaches of the Phase Nonlinearity of the Phase only Liquid Crystal Spatial Light Modulator
SHAN Xin, DUAN Mengyun, AI Yong, and HU Liang
Based on the TymanGreen interference system, the phase modulation character of the phaseonly liquid crystal spatial light modulator at 808 nm was studied. In order to increase the simulation fidelity of the atmospheric turbulence, the approximation method and the inverse interpolation method were used to compensate tBased on the TymanGreen interference system, the phase modulation character of the phaseonly liquid crystal spatial light modulator at 808 nm was studied. In order to increase the simulation fidelity of the atmospheric turbulence, the approximation method and the inverse interpolation method were used to compensate the phase nonlinearity of the spatial light modulator, and the calibration effect were compared with each other. Results show that, although the approximation method is straightforward, the inverse interpolation method can get a higher linearity of 0.991 6 and a lower calibration error of 0.06 rad. Moreover, after analyzing the calibration process and the error source, the inverse interpolation method is found to be more flexible to get a further improvement in the linear calibration, which is more significant to the pratical application of the liquid crystal spatial light modulator..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 623001 (2014)
Threeport Y Junction Optical Circulator Using a Ferrite Cylinder in Two dimensional Magnetophotonic Crystals
WANG Yong, ZHANG Dengguo, OUYANG Zhengbiao, and LI Jingzhen
A new defect structure of twodimensional magnetic-photonic crystal was proposed and applied to implement the threeport Yjunction circulator using a ferrite cylinder. External characteristics of the circulator were calculated by the plane wave expansion method and finite element method, the numerical results show thaA new defect structure of twodimensional magnetic-photonic crystal was proposed and applied to implement the threeport Yjunction circulator using a ferrite cylinder. External characteristics of the circulator were calculated by the plane wave expansion method and finite element method, the numerical results show that there is an agreement between the resonance frequency of microcavity constructed by a point defect in the 2D triangular lattice photonic crystal with those results of corresponding experiments. In the center frequency, the transmission efficiency of the circulator is the highest and there is no energy loss between output port and input port; the isolation and insertion loss of circulator respectively reach 23.2 dB and 0.003 7 dB. When frequency diverges from the center frequency, the transmission efficiency gradually decreases with increasing frequency offset, and the transmission characteristics of the circulator sharply deteriorated. This design of circulator with air as background, can overcome low isolation of circulator with an array of air holes, and solve the high loss from multiple ferrite cylinders, having obvious superiorities..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 623002 (2014)
The Analysis of the Photocarriers of the InGaAs pin Phtodiode Response to the High Optical Injection
HU Wei, DOU Xianan, and SUN Xiaoquan
To study the internal mechanism of the photodiode nonlinear response to the high energy laser pulse, the influence of the space charge screening on the photoelectric response characteristic of the InGaAs pin photodiode was calculated under the high optical injection. The electrical field, distribution of carriers andTo study the internal mechanism of the photodiode nonlinear response to the high energy laser pulse, the influence of the space charge screening on the photoelectric response characteristic of the InGaAs pin photodiode was calculated under the high optical injection. The electrical field, distribution of carriers and electronhole mobility in the depletion region were calculated respectively. The simulated results indicate that when the applied bias field is low or the laser pulse energy is high, the electrical field in the depletion region is suppressed and the driftdiffusion velocity is reduced to the unsaturated state. Therefore, the separation and recombination of the holeelectron is slowed down, lots of the photocarriers is in the depletion region, which leads to the nonlinear response due to the space charge screening. In the experiment, the InGaAs pin photodiode′s response voltage pulse width is widening and the peak voltage is increasing nonlinearly with the increasing 20 ps laser pulse energy in the 5 V applied bias. The calculation of the photodiode internal mechanism is proved to be valid by the experimental phenomena..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 625001 (2014)
Conversion Efficiency of Photon Enhanced Thermionic Emission Solar Converters with Exponential Doping GaAs Cathodes
TANG WeiDong, YANG WenZheng, YANG Yang, SUN ChuanDong, and CAI ZhiPeng
Photonenhanced thermionic emission solar energy converter is a new highly efficient solar energy utilization technologies. An exponential doping GaAs material was presented as the cathode of photonenhanced thermionic emission solar converter. The conversion efficiencies of the photonenhanced thermionic emission solaPhotonenhanced thermionic emission solar energy converter is a new highly efficient solar energy utilization technologies. An exponential doping GaAs material was presented as the cathode of photonenhanced thermionic emission solar converter. The conversion efficiencies of the photonenhanced thermionic emission solar devices with exponential doping GaAs were theoretically analyzed by using the energybalance and diffusiondriftemission models. The results show that exponential doping GaAs prominently enhances photonenhanced thermionic emission conversion, and the efficiency of photonenhanced thermionic emission solar converters with exponential doping GaAs cathodes is a monotonically increasing function of sun concentration and a monotonically decreasing function of cathode surface recombination velocities. The efficiency of the converter can reach 30% at a flux concentration larger than 200 suns and surface recombination velocities maintained at fewer than 104 cm/s..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 625002 (2014)
Study on K2Te(Cs) Solar Blind Ultraviolet Cathode
LI Xiaofeng, ZHAO Xuefeng, CHEN Qijun, and WANG Zhihong
The making process of K2Te(Cs) solar blind ultraviolet cathode was described and samples of K2Te(Cs) solar blind ultraviolet cathode were made. The spectral response, spectral reflectance and fluorescence spectra under the excitation condition of 250 nm wavelength about K2Te(Cs) and Cs2Te solar blind ultraviolet cathodThe making process of K2Te(Cs) solar blind ultraviolet cathode was described and samples of K2Te(Cs) solar blind ultraviolet cathode were made. The spectral response, spectral reflectance and fluorescence spectra under the excitation condition of 250 nm wavelength about K2Te(Cs) and Cs2Te solar blind ultraviolet cathodes were measured. The measuring results showed that under the existing technological condition, the spectral response of K2Te(Cs) solar blind ultraviolet cathode is higher, the peak wavelength of spectral response is shorter than that of Cs2Te solar blind ultraviolet cathode. However, their long wavelength thresholds of both cathodes were basically same. The peak wavelength of spectral response of K2Te(Cs) cathode is about 250 nm, long wavelength threshold is about 336 nm. In addition, K2Te(Cs) solar blind ultraviolet cathode has better solar blind property; the spectral sensitivity at 633 nm is ranked at the order of magnitude of 10－4 mA/W, one order of magnitudes lower than that of Cs2Te solar blind ultraviolet cathode. As for the spectral reflectance, the measuring results showed that the spectral reflectance of K2Te(Cs) solar blind ultraviolet cathode is higher than that of Cs2Te solar blind ultraviolet cathode within the scope of 200~437 nm wavelength, however is basically same as that of Cs2Te solar blind ultraviolet cathode within the scope of 437~600 nm wavelength, the refractive index and extinction coefficient of K2Te(Cs) solar blind ultraviolet cathode are less than that of Cs2Te solar blind ultraviolet cathodeThe measuring results on fluorescence spectra indicated that under the same condition and within the scope of 250~350 nm wavelength, the fluorescence of K2Te(Cs) ultraviolet cathode is stronger than that of Cs2Te ultraviolet cathode, the more strongly the fluorescence, the more transition electrons and the higher spectral response of cathode. The properties of K2Te(Cs) solar blind ultraviolet cathode are better than that of Cs2Te solar blind ultraviolet cathode, and thus can be applied to image device for solar blind ultraviolet detection as well..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 625003 (2014)
Classification of Hyperspectral Images by Fusion of Multifeature Under Kernel Mapping
FAN Liheng, LV Junwei, YU Zhentao, and CAO Liangjie
The spectral bands have strong relation with land covers both partically and theoretically.Thus it is possible to extract enough spectral features with the help of more efficient data represent methods to distinguish land covers. More pertinent spectral matching methods can be taken to improve the similarity and dissimThe spectral bands have strong relation with land covers both partically and theoretically.Thus it is possible to extract enough spectral features with the help of more efficient data represent methods to distinguish land covers. More pertinent spectral matching methods can be taken to improve the similarity and dissimilarity metric and to improve the performance of the classifiers.A couple of classic and efficient spectral measures,such as spectral angle mapper,spectral correlation mapper,mahalanobis distance,spectral similarity value and spectral information divergence,were selected.Then the RBF Guassian function was used and the spectral measure under the kernel mapping were obtained.A new method based on the fusion of multifeatures under kernel mapping was taken to dig the features of hyperspectral remote sensing data.Profile the similarity between different classes and thus a new classification algorithm was proposed.At last,this method was applied to a hyperspectral remotely sensing AVIRIS dataset named 92AV3C using the LIBSVM toolbox of MATLAB.The results show that the classification method of hyperspectral images by fusion of multifeatures under kernel mapping can significantly improve the accuracy of the classification. Experimental comparison shows the proposed algorithm can provide better performance for the pixel classification of hyperspectral image than many other wellknown techniques..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 630001 (2014)
Manifold based Semi supervised Feature Selection for Hyperspectral Data
WEI Feng, HE Mingyi, SHEN Zhiming, and LI Xu
The traditional Feature Selection methods of hyperspectral data include supervised and unsupervised modes, is not efficient for the real processing system in which abundant unlabeled and few labeled data coexist. Additionally, most of existing feature selection methods ignore that real data has a manifold structure whThe traditional Feature Selection methods of hyperspectral data include supervised and unsupervised modes, is not efficient for the real processing system in which abundant unlabeled and few labeled data coexist. Additionally, most of existing feature selection methods ignore that real data has a manifold structure which embedded into the high dimensional space. In order to solve these problems, a Manifold based Semisupervised Feature Selection (MSFS) algorithm was proposed. Considering the prior information of labeled data with the local and nonlocal invariance of the whole data, the discriminate structure is optimized through simultaneously maximizing betweenclass and minimizing withinclass variances. Meanwhile, the manifold structure is exploited from constructing local and nonlocal graphs for the whole data. Then, the efficient features is selected by defining an appropriate evaluation criterion. Finally, through performing the classification experiment on the selected features of real hyperspectral data, it demonstated that our method is able to retain the main structure of data after dimensionality reduction well..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 630002 (2014)
Astigmatism Compensation in Imaging Spectrometer Based on Concentric Offaxis Dual Reflector System
CHEN Tingai, TANG Yi, ZHANG Lijun, CHANG Yuee, and ZHENG Cheng
A specific imaging spectrometer based on concentric offaxis dual reflector system was proposed which consisted of four spherical mirrors and a plane grating. On the basis of analysis of the concentric offaxis dual reflector system, aberration theory and optical pathlength concept were used to derive an expression foA specific imaging spectrometer based on concentric offaxis dual reflector system was proposed which consisted of four spherical mirrors and a plane grating. On the basis of analysis of the concentric offaxis dual reflector system, aberration theory and optical pathlength concept were used to derive an expression for the separation of astigmatic images in concentric offaxis dual reflector system, the astigmatism elimination in which was found further. It is shown that the astigmatism of the imaging spectrometer can be eliminated by applying concentric offaxis dual reflector system without astigmatism in both the collimating and condensing optics. A symmetrical and concentric imaging spectrometer was described and a generalized design procedure was shown. The symmetrical and concentric imaging spectrometer working in farultraviolet (120~180 nm) wavelength was simulated by applying the design procedure. To verify the stigmatic principle, spot diagram and the curves of astigmatism were shown. The results show that the initial structure satisfies the stigmatic principle well. The spectral resolution of the optimized spectrometer is close to 1.6 nm and the modulation transfer function is more than 0.37 for the total field of view at all wavelengths, which provides good imaging quality..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 630003 (2014)
Laser tweezer Raman Spectroscopy Study of Single Rat Fetal Liver Stem Cell
WANG Yanjun, QIN Zongding, YAO Huilu, WANG Yun, and FENG Meifu
Laser tweezers Raman spectroscopy system is an optical technique combining the laser tweezers and Raman spectroscopy technique, which could be able to study recognition and detect constituent components of single biological cell in close to its natural state. Rat fetal liver stem cells at 10~21 days of gestation and adLaser tweezers Raman spectroscopy system is an optical technique combining the laser tweezers and Raman spectroscopy technique, which could be able to study recognition and detect constituent components of single biological cell in close to its natural state. Rat fetal liver stem cells at 10~21 days of gestation and adult rat hepatocytes were separated by collagenase digestion. Single fetal liver stem cell, hepatocyte and WBF344 rat liver stem cell line were detected by laser tweezers Raman spectroscopy technique, and their Raman spectrum was compared. It was indicated that the value of 1 336 cm－1 (assigned to Polynucleotide chain, DNApurine bases) and 1 446 cm －1(CH2 bending mode of proteins) band increased before 13th day and decreased after 14th day of gestation, and the mean of peak value of 1 336 cm－1 and 1 446 cm－1 bands at 13th day of gestation was the highest. The results showed that the Laser tweezers Raman spectroscopy system could differentiate fetal liver stem cells of different period of gestation from adult hepatocytes, and analyze differentiation and development mechanism of fetal liver stem cells, which lay a foundation for clinical application of hepatic stem cells therapy..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 630004 (2014)
Apoptosis Process under High Concentrations of Ethanol Stress at a Single Cell Level with Raman Spectroscopy
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
At group cells level and a single yeast level, laser tweezers Raman spectroscopy was used to monitor the dynamic of the intracellular biological macromolecular in realtime during the apoptosis process of yeast cells stressed with high concentrations of ethanol. The results show that the intensities of Raman peaks of nAt group cells level and a single yeast level, laser tweezers Raman spectroscopy was used to monitor the dynamic of the intracellular biological macromolecular in realtime during the apoptosis process of yeast cells stressed with high concentrations of ethanol. The results show that the intensities of Raman peaks of nucleic acids (721, 1 083, 1 301 cm－1), proteins (721, 858, 1 001, 1 301, 1 445, 1 608, 1 657 cm－1) and lipids (1 083, 1 301, 1 445 cm－1) decreased significantly along with the extension of treatment time, indicates that the contents of nucleic acids, proteins and lipids are reduced gradually while the yeast cells are undergoing apoptosis induced by high concentrations of ethanol. However, the results of single factor analysis and repeated measures analysis show that the changes of the intensities of Raman peaks between the group cells and the single cells are difference significantly, implies that the heterogeneities of the single cells are covered by the average spectroscopy of the population cells. The results display that laser tweezer Raman spectroscopy can be used to directly and truthfully detect the kinetic apoptosis process under high concentrations of ethanol stress at the single cell level and probe cellular heterogeneity..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 6, 630005 (2014)
© Copyright 2018-2021 | Chinese Laser Press. All Rights Reserved 沪ICP备15018463号-20