Journals >Acta Photonica Sinica
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2012
Volume: 41 Issue 10
23 Article(s)
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Research Article
A Cloud Elimination Algorithm Based on Differential Absorption Lidar
FAN Guang-qiang, LIU Jian-guo, LIU Wen-qing, LU Yi-huai, ZHANG Tian-shu, DONG Yun-sheng, and ZHAO Xue-song
The cloud signals can cause severe wobble of tropospheric ozone concentration in the process of differential absorption lidar measurement of ozone concentration, and bring significant errors. A cloud elimination algorithm is presented. The algorithm effectively eliminate tropospheric ozone wobble by interpolating the oThe cloud signals can cause severe wobble of tropospheric ozone concentration in the process of differential absorption lidar measurement of ozone concentration, and bring significant errors. A cloud elimination algorithm is presented. The algorithm effectively eliminate tropospheric ozone wobble by interpolating the ozone concentration in cloud height region. The key point of the cloud algorithm is given through expounding its theoretical basis. The key point of the cloud elimination is the discrimination of cloud signal and accurate positioning of the cloud height. The cloud height information is determined by setting the aerosol extinction coefficient threshold according to the characteristics of the cloud extinction coefficient. The cumulative average of retrieved ozone concentration reduces measurement errors caused by noise. The results show that the correction by interpolation algorithm of ozone measurements in cloud region could overcome the wobble of the ozone measurements caused by clouds..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 1135 (2012)
Detection of Bottom Aerosols in Urban Area using Micro-pulse Polarization Lidar
SONG Yue-hui, HUA Deng-xin, LI Shi-chun, WANG Yu-feng, DI Hui-ge, and QIANG Li-hu
A portable micro-pulse polarization lidar system with 3D scanner at eye-safety level is developed, in which Nd∶YAG pulsed laser is employed as the exciting source with 2 μJ pulse energy and 1 kHz repetition rate, to detect the spherical characteristics and distribution of bottom aerosols in urban area. To ensure high aA portable micro-pulse polarization lidar system with 3D scanner at eye-safety level is developed, in which Nd∶YAG pulsed laser is employed as the exciting source with 2 μJ pulse energy and 1 kHz repetition rate, to detect the spherical characteristics and distribution of bottom aerosols in urban area. To ensure high accuracy detection near the earth's surface at the range from 80 m to 1000 m in the region of high-density aerosols such as northwest region, analog photoelectric detection technique is adopted. Continuous observations with scanning in zenith angle are carried out for the first time for depolarization ratio of atmospheric aerosols below 1 km in Xi′an in winter, the results of depolarization ratio scanning profiles are obtained and the effect of weather process and state of ground on depolarization ratio is analyzed. The experimental results show that, the depolarization ratio is around 0.1, where there were no sandstorms during the observations, and the depolarization ratio in certain regions is relative higher, which are occurred at the crossings of roads without greenbelts. The experimental results validate the feasibility of the system and will also provide scientific data for investigating the generation, transmission and diffusion characteristics of urban pollution particles..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 1140 (2012)
Investigation on the Output Characteristics of LD End-pumped Cr4+∶YAG Passively Q-switched Laser
YANG Xiao-dong, and HOU Xin-hua
The output characteristics of a LD end-pumped Cr4+∶YAG passively Q-switched Nd:YAG laser are experimentally investigated. The experiment shows that the output power and pulse repetition rate increases with the cavity length. To explain above experiment phenomenon, the pump laser beam sizes in the Nd:YAG crystal are meaThe output characteristics of a LD end-pumped Cr4+∶YAG passively Q-switched Nd:YAG laser are experimentally investigated. The experiment shows that the output power and pulse repetition rate increases with the cavity length. To explain above experiment phenomenon, the pump laser beam sizes in the Nd:YAG crystal are measured, and the fundamental mode laser beam radius in the Nd∶YAG crystal and the Cr4+∶YAG crystal are calculated. The investigations show that two reasons result in the output power and pulse repetition rate increasing with the cavity length. Firstly, the pump beam size in the Nd∶YAG crystal is far less than the fundamental mode laser beam in the Nd:YAG crystal. The overlap efficient between pump and the laser beam is low. With the cavity length increasing, the fundamental mode laser beam in the Nd∶YAG crystal decreases, which results in the overlap efficient between pump beam and the laser beam increasing. So the output power and the pulse repetition rate increase with the cavity length increasing. Secondly, the laser beam radius in the Cr4+∶YAG crystal also decreases with the cavity length, which shorten the time interval between two bleaching of the Cr4+∶YAG crystal. So the pulse repetition rate increases with the cavity length..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 1145 (2012)
Heterodyne Laser Doppler Vibrometer Based on Double Acousto-optic Frequency Shifters
SHANG Jian-hua, REN Li-hong, XU Hai-qin, ZHAO Shu-guang, and HE Yan
The influence on the measured vibration signal caused by the frequency-stability and signal power of driver signal to acousto-optic frequency shifter (AOFS) in the high-precision heterodyne laser doppler vibrometry (HLDV) with one AOFSs was analyzed. In order to reduce the frequency drifting and the phase noise of the The influence on the measured vibration signal caused by the frequency-stability and signal power of driver signal to acousto-optic frequency shifter (AOFS) in the high-precision heterodyne laser doppler vibrometry (HLDV) with one AOFSs was analyzed. In order to reduce the frequency drifting and the phase noise of the driver signal, the HLDV composed with two AOFSs was proposed. And based on the direct digital frequency synthesis (DDS) technology, the design of the driving signal generation unit has been completed with AD9912 which has the characteristic of adjustable initial-phase and low phase noise. The vibration-measuring experiments performed with HLDV consists of two AOFS shows that the designed generation unit is able to drive the AOFS. Meantime, compared with the HLDV with one AOFS, the noise floor from 0 to 10 kHz of the HLDV with two AOFS is flat and the noise distribution below 1 kHz has been depressed greatly..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 1149 (2012)
Comparison on Terahertz Transmission Based on Spoof Surface Plasmon Polaritons Between Bull’s Eye Structures with Different Ring Grooves
GAO Chun-mei, CHEN Lin, XIE Le, PENG Yan, CHEN Ke-jian, CAI Bin, and ZHU Yi-ming
To study the effect of different circular groove numbers of bull′s eye structures on the enhanced transmission in terahertz region, two bull′s eye samples were fabricated with five circular grooves and fifteen circular grooves on aluminum slabs, respectively. Transmitted terahertz signals from two bull′s eye samples weTo study the effect of different circular groove numbers of bull′s eye structures on the enhanced transmission in terahertz region, two bull′s eye samples were fabricated with five circular grooves and fifteen circular grooves on aluminum slabs, respectively. Transmitted terahertz signals from two bull′s eye samples were obtained by using terahertz time-domain spectroscopy. Experimental results show that for both samples, broad-band terahertz reference signal from 0.1 THz to 2.7 THz was filtered to be narrow-band signal, the center peak was at 0.53 THz, the transmission efficiency can reach 55.7% by five circular grooves and 68.3% by fifteen circular grooves through the center holes respectively. The differences on band widths and amplitudes of transmitted terahertz signals from small sample and big sample with different circular groove numbers come from insufficient periodical extension and leakage from edge of structure. Furthermore, spoof surface plasmon polaritons theory was employed to analyze filter phenomena of transmitted signals from different size bull′s eye structures with the help of finite element method. The simulated results agree well with the experimental results, both proved that the circular groove numbers can affect the enhancemen of the transmission in terahertz region..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 1156 (2012)
Wideband Photonic Microwave Downconversion Based on an Optoelectronic Oscillator for Uncompressed HD Video Distribution
TANG Zhen-zhou, PAN Shi-long, ZHOU Pei, ZHU Dan, GUO Rong-hui, and BEN De
Wideband photonic microwave downconversion based on an optoelectronic oscillator (OEO) is proposed and demonstrated for the uncompressed HD video radio-over-fiber (RoF) transmission system. By using the injection locking of the OEO, high-quality RF carrier is extracted from the optical microwave signal. The extracted RWideband photonic microwave downconversion based on an optoelectronic oscillator (OEO) is proposed and demonstrated for the uncompressed HD video radio-over-fiber (RoF) transmission system. By using the injection locking of the OEO, high-quality RF carrier is extracted from the optical microwave signal. The extracted RF carrier is then fed back to the modulator to perform the downconversion in the optical domain. An experiment is performed. The distribution and downconversion of the signal with a carrier frequency of 10 GHz and a data rate of ≥2 Gb/s is verified. The wireless distance is 0.5 m and the length of optical fiber is 10 km. The distribution of a real-time 1.5-Gb/s uncompressed HD video is also demonstrated in the radio over fiber link. The results show that the system features wide bandwidth and low electromagnetic interference. Meanwhile, thanks to the automaic phase tracking of the OEO, no additional phase-locking operation is needed. The overall system is simple and stable, which provides a presentation and demonstration platform for HD video transmission..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 1161 (2012)
Influence of Nickel Impurity on the Performance of GaAs Solar Cells with Impurity Photovoltaic Effect
YUAN Ji-ren, HONG Wen-qin, DENG Xin-hua, and YU Qi-ming
The solar cell with impurity photovoltaic effect can make use of the solar photons with energies less than the bandgap so that its conversion efficiency could be improved. To improve the conversion efficiency of the GaAs solar cells by using impurity photovoltaic effect, the GaAs solar cells doped with nickel for impurThe solar cell with impurity photovoltaic effect can make use of the solar photons with energies less than the bandgap so that its conversion efficiency could be improved. To improve the conversion efficiency of the GaAs solar cells by using impurity photovoltaic effect, the GaAs solar cells doped with nickel for impurity photovoltaic effect were investigated by numerical method. The influence of nickel-doping on the short-circuit current density, open-circuit voltage and conversion efficiency was investigated. The effect of trapping structure on the cell performance was discussed. The results show that an increase of the conversion efficiency 3.32% can be achieved due to the impurity photovoltaic effect. The improvement of the solar cell performance attributes to the absorption of some sub-band photons, which results in the extension of the infrared response. Moreover, a good light trapping should be required to obtain better device performance for solar cells with impurity photovoltaic effect. It can be concluded that nickel doping in GaAs solar cells with impurity photovoltaic effect is a promising way for higher efficiency..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 1167 (2012)
Component Uniformity Study on Na2KSb Film of Multi-alkali Photocathode
LI Xiao-feng, LU Shing-lin, YANG Wen-bo, and ZHAO Xue-feng
The measurement principle of fluorescence spectrum on Na2KSb film of multi-alkali photocathode was described and three samples were measured in the position of different radius. The data result shows that the peak wavelength of fluorescence spectrum on Na2KSb film from center to edge of the cathode surface gradually inThe measurement principle of fluorescence spectrum on Na2KSb film of multi-alkali photocathode was described and three samples were measured in the position of different radius. The data result shows that the peak wavelength of fluorescence spectrum on Na2KSb film from center to edge of the cathode surface gradually increases, and the peak fluorescence intensity gradually increased as well. The reason is that the antimony atom density of cathode surface from the center to the edge gradually reduces. When the antimony in Na2KSb film exceeds stoichiometry required, the fluorescence peak wavelength shifts towards the short-wave direction, while the fluorescence intensity decreased at the same time. When the antimony in Na2KSb film achieves stoichiometry required, the fluorescence peak wavelength reaches the maximum value, while the fluorescence intensity reaches the strongest at the same time. By fluorescence test one can judge whether the stoichiometry of Na2KSb film reaches to the ratio 2:1:1 or not, in another words whether antimony in Na2KSb film is overdose or not. In addition by measuring the fluorescence spectra at different positions of the cathode surface, we can measure component uniformity in the Na2KSb cathode film. The more uniform antimony atom density is in the cathode surface, the more accurate the monitor method of film growth by measuring changes of the cathode photocurrent is, thus component uniform can be better, Na2KSb film thickness can be thicker, long-wave absorption of visible light is more, the sensitivity of the cathode is higher. Therefore, during the manufacturing process of multi-alkali cathode of image intensifier, one has to make the uniform antimony atoms density on cathode window surface in order to achieve higher sensitivity..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 1171 (2012)
Design of Zigzag Staggered Barrier for Autostereoscopic Display
YAO Jian-min, XIN Qi, and GUO Tai-liang
Parallax barrier based autostereoscopic display is usually impaired by moire fringe and crosstalk. By using slanted parallax barrier, the moire fringes could be obviously eliminated, but often at the expense of serious image crosstalk. This paper presents a kind of zigzag staggered barrier which can reduce the moire frParallax barrier based autostereoscopic display is usually impaired by moire fringe and crosstalk. By using slanted parallax barrier, the moire fringes could be obviously eliminated, but often at the expense of serious image crosstalk. This paper presents a kind of zigzag staggered barrier which can reduce the moire fringe with little impact on the stereo viewing zones. The slits are divided into sections and the adjacent two jagged-edged sections are separated horizontally at a certain distance. This method can reduce the proportion of the perceived black matrix seen through the same slit, which increasing the brightness of the dark part of the moire fringe. In this way widen and weakened moire fringes are acquired. The simulated results show that the minimum perceived moire fringes’ brightness decreases by 108.1% and the viewing zones decreases by 32.8% compared with the vertical parallax barrier. And it has higher practical value for autostereoscopic display..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 1176 (2012)
Design of Centering System by Using Collimation and Interference with Two Channels
FANG Chao, and XIANG Yang
In order to meet different centering measurement demands when edging and assembling the projection lens, a centering system by using collimation and interference with two channels is proposed. The system use collimation and interference in the same optical configuration. Parameters of the measurement system are designeIn order to meet different centering measurement demands when edging and assembling the projection lens, a centering system by using collimation and interference with two channels is proposed. The system use collimation and interference in the same optical configuration. Parameters of the measurement system are designed, and measurement range, sensitivity and the measurement accuracy are analyzed in theory. The results show that measurement range of the system by using collimation is from 1 μm to 500 μ m, the highest sensitivity is 0.2%, and accuracy reach 1.02 μm; the measurement range of the system by using interference is from 0.01 μm to 1.9 μ m, the lowest sensitivity is 0.1%, and accuracy reach 0.2 μm. The design can satisfy demands of a wide range, low sensitivity, low accruacy in centering-edging stage, and small range, high sensitivity, high accruacy in assembling stage. The centering system can meet the design requirements, and can guide the production and assembly of lithographic projection lens..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 1180 (2012)
Optical Design of Digital Movie Zoom Projection Lens
LI Wei-shan, CHEN Chen, ZHANG Yu, and LIU Xiao-chan
To fill the vacancy of domestic short focal range digital movie zoom projection lens and to meet the requirement of the market, a digital movie zoom projection lens for 0.65 inch DLP 1.3 K digital movie projector was designed by the mechanical compensation method. It includes the former fixed group, the zoom group, theTo fill the vacancy of domestic short focal range digital movie zoom projection lens and to meet the requirement of the market, a digital movie zoom projection lens for 0.65 inch DLP 1.3 K digital movie projector was designed by the mechanical compensation method. It includes the former fixed group, the zoom group, the compensation group and the last fixed group. It is composed of ten glass sphere lenses, and the zoom group is composed of one negative lens, the compensation group is composed of two doublet lenses. The total length of the digital movie zoom projection lens is 170 mm, the full aperture is 70 mm. Its focal length range is 14.5～18.2 mm, F-number is 2, projection ratio range is 0.99∶1～1.23∶1, and the BFL is 32.6 mm. The cam curves were designed with the method of equal interval zoom. The image quality in each focal length is excellent with advantages of simple structure, small size, and low cost, and its cam curves are smooth without cam inflexions and processed easily..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 1186 (2012)
[in Chinese]
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Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 1193 (2012)
Application of Precise Integration in Numerical Simulation of One-dimensional Photonic Crystal
YANG Hong-wei, MU Zhen-feng, and JIANG Shu-ning
Transmission coefficient of the one-dimensional photonic crystal with various dielectric materials is simulated by using precise integration, and simulation results are analyzed. Photonic crystal is divided into different sections. Potential energy of the section and mixed energy of the section are introduced. The expoTransmission coefficient of the one-dimensional photonic crystal with various dielectric materials is simulated by using precise integration, and simulation results are analyzed. Photonic crystal is divided into different sections. Potential energy of the section and mixed energy of the section are introduced. The export stiffness matrix of each section can be obtained by using precise integration, and then each stiffness matrix is combined. The problem can be solved by imposing boundary conditions on the stiffness matrix. The curves of lose rate D are drawn to check the validity and accuracy of the numerical solution. The simulation results show that this method is accurate, efficient and applicable for the simulation of one-dimensional photonic crystal..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 1200 (2012)
Amplification Effect of Micro Vibration in Water
MIAO Run-cai, WANG Wen-cheng, XU Jia-ting, and XIE Tian
According to the acousto-optic effect, a measurement system of the vibration in the solid surface was built by laser diffraction. When the laser beam illuminated obliquely to the liquid surface wave caused by the vibration, the clear and very high diffraction pattern was observed. The diffraction pattern was scanned byAccording to the acousto-optic effect, a measurement system of the vibration in the solid surface was built by laser diffraction. When the laser beam illuminated obliquely to the liquid surface wave caused by the vibration, the clear and very high diffraction pattern was observed. The diffraction pattern was scanned by use of MATLAB software. The light intensity distribution of the diffraction pattern was received. Based on the analytical relationship between the diffraction pattern width and the amplitude of the surface wave, the amplitude was obtained. And its size was in microns category. When the depth of the sample pool was changed, the surface wave amplitude was given. The relationship between liquid depth and the amplitude was provided. And the amplification effect concerning the vibration of the liquid was found. Then the vibration amplitude in the solid surface was got. Therefore the micro vibration in the solid surface was achieved..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 1205 (2012)
Phase Demodulation Using a Single Deformed Fringe Pattern by Wavelet Analysis
YANG Chu-ping, WENG Jia-wen, LI Hai, and TAN Sui-yan
To realize phase demodulation using a single deformed fringe pattern in 3D fringe sensing, a method is proposed. In the method, instantaneous frequency estimation of wavelet transform is applied to the deformed fringe pattern, and derivative frequency is used to directly extract the fundamental spectrum of the originalTo realize phase demodulation using a single deformed fringe pattern in 3D fringe sensing, a method is proposed. In the method, instantaneous frequency estimation of wavelet transform is applied to the deformed fringe pattern, and derivative frequency is used to directly extract the fundamental spectrum of the original fringe pattern from the instantaneous spectrum of its deformed fringe pattern. Firstly, theoretical analysis shows that if the instantaneous frequency at a certain position of the deformed fringe pattern is equal to the fundamental frequency of its original fringe pattern, the derivative frequency at such position is zero. Secondly, the instantaneous spectrum of the deformed fringe pattern is experimentally estimated by Gabor wavelet transform. Finally, the fundamental spectrum of the original fringe pattern is identified and obtained from the above instantaneous spectrum. It means that a single deformed fringe pattern is enough to realize phase demodulation. Experimental results of 3D shape measurement show the good effect of the proposed method in phase modulation..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 1211 (2012)
Image Reconstruction Based on Weak Selected Regularized Orthogonal Match Pursuit Algorithm
LIU Zhe, ZHANG He-ni, ZHANG Yong-liang, and HAO Min-hui
Regularized Orthogonal Match Pursuit(ROMP) is widely applied as a signal reconstruction algorithm. Despite its high efficiency, ROMP requires the prior knowledge of signal sparsity, and would be unstable if the sparsity level is improperly estimated. To overcome this drawback, a weak selection strategy was introduced tRegularized Orthogonal Match Pursuit(ROMP) is widely applied as a signal reconstruction algorithm. Despite its high efficiency, ROMP requires the prior knowledge of signal sparsity, and would be unstable if the sparsity level is improperly estimated. To overcome this drawback, a weak selection strategy was introduced to adaptively determine the number of atoms and the candidate atoms by estimating the relevance between iterative residue and measurement matrix of the original ROMP algorithm. Thus, an optimal atom set for the signal reconstruction procedure could be selected from the candidate atoms according to the regularization principle. Numerical results demonstrate that the proposed method outperforms other greedy algorithms with 0.5~1.5 dB higher PSNR and much lower MSE..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 1217 (2012)
A Novel Self-correcting Algorithm for False Corner of Harris Operator on Calibration Image
LIU Ning, LU Rong-sheng, XIA Rui-xue, and LI Qi
A novel method is depicted in this paper to handle the probably existed false corners from the feature extraction on calibration image using Harris operator. It performs x and y directional sub-pixel scans in the neighborhood of false corners respectively, then line fitting or curve fitting method based on orthogonal dA novel method is depicted in this paper to handle the probably existed false corners from the feature extraction on calibration image using Harris operator. It performs x and y directional sub-pixel scans in the neighborhood of false corners respectively, then line fitting or curve fitting method based on orthogonal distance is employed to compute the intersection of two edge lines for the purpose of replacing the location of false corner. A lot of experiments on the images of chessboard for machine calibration show that the method is of robustness, and achieve two expectant objectives: 1) amend false corners in result; 2) get the sub-pixel level corners of high accuracy..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 1222 (2012)
A Robust Object Detecting and Tracking Method
JIA Wei, SUN Wei, and LI Da-jian
According to the problem of error accumulation and matched feature points loss in the optical flow feature tracking method, a predictive frame and key frame algorithm framework is proposed based on the new Harris-SIFT feature representation method. The proposed target tracking algorithm was realized by combining opticaAccording to the problem of error accumulation and matched feature points loss in the optical flow feature tracking method, a predictive frame and key frame algorithm framework is proposed based on the new Harris-SIFT feature representation method. The proposed target tracking algorithm was realized by combining optical flow motion estimation and local feature recognition. Predictive frame uses pyramid decomposition and recursive algorithm to compute the motion vectors from optical flow field characteristics. The proposed algorithm gets motion vector of the target and eliminates false matching point from motion vector histogram; when the number of matched point is less than 5, the key frames uses the Harris-SIFT feature point for local feature matching, and affine model was used for accurate target positioning and attitude correction. The experiment results show that the proposed algorithm still can continue to achieve reliable tracking in complex background, target occlusion or temporarily lost case..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 1230 (2012)
Two-stage Retinal Fundus Image Registration Based on Local Blood Structure Features
SHEN Ben, ZHANG Dong-bo, and PENG Ying-hui
A two-stage registration algorithm combining global registration and local registration technology is proposed. In this algorithm, bifurcation structures with 4 connected bifurcation points rather than single bifurcation points are used as the registration features. By reducing pairing points, the efficient of registraA two-stage registration algorithm combining global registration and local registration technology is proposed. In this algorithm, bifurcation structures with 4 connected bifurcation points rather than single bifurcation points are used as the registration features. By reducing pairing points, the efficient of registration is improved. Moreover due to non-linear deformation, there are some registration errors appear in some local region. To solve this problem, a local registration technology is introduced according to the global registration results, which improve registration precision. Experiment results show that the algorithm effectively achieve fundus image registration with higher efficient and precision..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 1236 (2012)
Preparation and Properties of Zn-doped β-Ga2O3 Films
ZHAO Yin-nü
β-Ga2O3 is a wide band gap semiconductor with a band gap of Eg≈5.0 eV, which has potential optical and optoelectronic applications. The intrinsic β-Ga2O3 and Zn-doped β-Ga2O3 films were prepared on Si (111) and UV transparent quartz substrates using RF magnetron sputtering. The optical transmission, optical absorption,β-Ga2O3 is a wide band gap semiconductor with a band gap of Eg≈5.0 eV, which has potential optical and optoelectronic applications. The intrinsic β-Ga2O3 and Zn-doped β-Ga2O3 films were prepared on Si (111) and UV transparent quartz substrates using RF magnetron sputtering. The optical transmission, optical absorption, structural property, photoluminescence were measured using a double beam spectrophotometer, X-ray diffractometer, fluorescence spectrometer. The effects of the Zn doping and thermal annealing on the structural and optical properties were investigated. The post-annealed β-Ga2O3 films are polycrystalline. In comparison with the intrinsic β-Ga2O3 films, the intensity of the Zn-doped β-Ga2O3(111) peak becomes weak, the crystallization deteriorates, the (111) peak position shifts from 35.69° to 35.66°. For the post-annealed Zn-doped β-Ga2O3 films, the optical band gap shrinks, the transmittance decreases, the absorption increases, the near-edge absorption appears, and the UV, blue, green emission bands are enhanced. It means that the doped Zn atoms are activated effectively after annealing and act as acceptors..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 1242 (2012)
Influence of the Oxygen Flow on TiO2 Thin Films Prepared by DC Magnetron Sputtering
FAN Xiao-juan, LAI Zhen-quan, and LI Rui
TiO2 thin films were prepared by DC reactive magnetron sputting using high putity Ti as the targets and high O2 as the reaction gas. The influence of the oxygen flow on the film crystalline orientation,surface morphology and optical properties were studied. The results show that the TiO2 films is anatase TiO2 (101) preTiO2 thin films were prepared by DC reactive magnetron sputting using high putity Ti as the targets and high O2 as the reaction gas. The influence of the oxygen flow on the film crystalline orientation,surface morphology and optical properties were studied. The results show that the TiO2 films is anatase TiO2 (101) preferred orientation; when the oxygen flow rate is small, the film also contains metal Ti(100); when the oxygen flow was larger, the films containing TiO2(101) and (004) into a polycrystalline state;the roughness and particle size of the films increases with oxygen flow; film visible- near-infrared bands have a higher transmission rate and the absorption peak increases with the oxygen flow in the 400~1 100 nm redshift; when oxygen flow 5 sccm, the average transmission is largest..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 1247 (2012)
Model and Simulation of Entanglement Signaling Repeater Network Based on Entanglement Swapping
LIAN Tao, and NIE Min
Aiming at the quantum signalling repeater network model for multi-user, environment quantum noises effect on remote transmission of signalling was studied. A kind of quantum signaling repeater strategy was purposed after the theory of quantum swapping being analyzed. Then a bus network model was put forward and the sucAiming at the quantum signalling repeater network model for multi-user, environment quantum noises effect on remote transmission of signalling was studied. A kind of quantum signaling repeater strategy was purposed after the theory of quantum swapping being analyzed. Then a bus network model was put forward and the success rate of long distance quantum signaling transmission was simulated. The results show that long distance signaling transmission has a close relationship with the noise power spectral density, transmission distance and repeater times. When noise power spectral density is constant and there is no repeater during the transmission process, the success rate declines like plesio-flat-parabola with increasing of the transmission distance. On the condition of constant noise power spectral density and constant transmission distance, the success rate increases obviously while the repeater times is increasing. Therefore, on the behalf of reliable quantum signaling transmission the transmission distance and repeater times should be designed properly under the circumstance of constant background noise..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 1251 (2012)
Damage Model of Quantum Signaling of Multi-user Based on Malicious Attack and Repair Strategy
LI Chao, and NIE Min
A quantum signaling tree transmission system of multi-user is presented, and the transmission process of signaling is described. The damage model of Trojan horse attack to signaling in the transmission process and the repair necessity are studied. The idea of quantum key distribution is introduced to the safety of quanA quantum signaling tree transmission system of multi-user is presented, and the transmission process of signaling is described. The damage model of Trojan horse attack to signaling in the transmission process and the repair necessity are studied. The idea of quantum key distribution is introduced to the safety of quantum signaling in direct communication, and non-orthogonal quantum states are analyzed to overcome the problem of Trojan horse attack that will improve the safety of the signal transmission. Quantum signaling tree transmission system of multi-user is improved, and a new general transmission model of multi-user quantum signaling tree topology is presented.The result shows that repair strategy of multi-user quantum signaling transmission system being attacked can effective detect the Trojan horse attack, and increases distance of security transmission, to ensure the signaling transmission process safely and effectively..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 10, 1256 (2012)
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