Journals >Acta Photonica Sinica
Contents
2013
Volume: 42 Issue 1
24 Article(s)
Export citation format
Research Article
A Method for Improving the Color Purity and Angle-dependent Character of Red Top-emitting Organic Light-emitting Device
GUO Run-da, WANG Peng, CHEN Yu, YUE Shou-zhen, ZHAO Yi, and LIU Shi-yong
Ag was deposited onto Si/SiO2 substrate as anode, 4,4,4-tris(3-methylphenylpheny-lamino)-triphenylamine(m-MTDATA):MoOx/m-MTDATA/N,N-bis-(1-naphthyl)-N,N-diphenyl-1,1-biphenyl-4,4-diamine(NPB) were used as hole-injected layer and hole-transporting layer,respectively. 4,4-N,N-dicarbazole-biphenyl(CBP) doped with (1-(phenAg was deposited onto Si/SiO2 substrate as anode, 4,4,4-tris(3-methylphenylpheny-lamino)-triphenylamine(m-MTDATA):MoOx/m-MTDATA/N,N-bis-(1-naphthyl)-N,N-diphenyl-1,1-biphenyl-4,4-diamine(NPB) were used as hole-injected layer and hole-transporting layer,respectively. 4,4-N,N-dicarbazole-biphenyl(CBP) doped with (1-(phenyl)isoquinoline) iridium (III) acetylanetonate(Ir(piq)2(acac)) was chosed as emitting layer. 4,7-di-phenyl-1,10-phenanthroline(BPhen) worked as hole-blocking layer and electronic-transporting layer. LiF(1 nm)/Al(2 nm)/Ag(20 nm) were composite cathode. In order to improve the outcoupling character of the top-emitting device, an organic CBP layer was introduced above the cathode. Appropriate use of the optical outcoupling layer is helpful for improving the transmittance of the composit cathode film system, and caused the color of the emitting light moved to deep-red region. The angle-dependent properties of the devices were also investigated and the ones with optical outcoupling layer show better performance. And it is very meaningful to the production of high-quality displays. In further study, another 20 nm NPB doped with Ir(piq)2(acac) was introduced to form dual emitting-layer structure, and while the driving voltage of the devices did not significant increase due to the relative high hole mobility of NPB. Meanwhile efficient triplet energy transfer between the host and guest is obtained, the recombination zone is broadened and the non-radiative losses is reduced, seen from the experimental, the current efficiency and color purity are both improved for the dual emitting-layer devices compared with the single emitting-layer structures..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 1, 1 (2013)
Photoemission Process Study of Multi-alkali Photocathode in the Super Second Generation Image Intensifier
LI Xiao-feng
Multi-alkali photocathode in super generation image intensifier is different from previous multi-alkali photocathode between the production processes, so the photoelectric emission characteristics are different from previous multi-alkali photocathode. In this paper, through the measurement of multi-alkali photocathode Multi-alkali photocathode in super generation image intensifier is different from previous multi-alkali photocathode between the production processes, so the photoelectric emission characteristics are different from previous multi-alkali photocathode. In this paper, through the measurement of multi-alkali photocathode spectral reflectivity and transmissivity, according to the law of conservation of energy, cathode spectral absorption rate was obtained. Spectral absorption rate indicates that, only when the photon energy greater than 1.333 eV, cathode absorption rates began to increase quickly. The cathode spectral absorption shows that cathode will not absorb any photons if light incident photon energy is less than the absorption limit, i.e. 933 nm wave absorption limit. In the cathode surface electron affinity further reduced circumstances, cathode photoemission long wave theory threshold is determined by long-wave absorption limit. In the electronic transition process after absorption of a photon, transition energies increase less than the absorption of the incident photon energy, i.e. the presence of an “energy loss”. The higher energy of a photon is, the higher electronic transition energy level is, the more energy loss is. At the same time, the higher energy of a photon is; the higher-energy level transition electron, the lower electronic transition probability is. Photocathode quantum efficiency is determined by the absorption rate, the transition probability and transition level, energy loss of diffusion process and other factors, thus photocathode quantum efficiency is in the presence of long wave threshold and shortwave threshold also. Photocathode quantum efficiency in 587 nm reaches the maximum value, after that decreases with the photon energy increases, when 3.6 eV, the quantum efficiency is reduced to zero. Cathode in photon energy of 3.6 eV the absorption coefficient is still high, but due to the electronic transition probability is low, while the electron diffusion process of energy loss is big, thus in spite of cathode on lower wavelength has high absorption coefficient, but the quantum efficiency is still low. Therefore on shortwave, cathode absorbed shortwave photon energy is converted into a photoconductive, lattice vibration and other forms of energy; the photoelectric emission utilization rate is very low..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 1, 7 (2013)
A p-n Junction Modulation Technique for Printed Thin Film Solar Cell
ZHU Zi-cheng, WANG Wei, JIANG Chen, and ZHOU Fang-fang
The scarcity of materials with band gap value of 0.5~0.85 eV is one of the major challenges for the multi-junction solar cells. In this study, the compounds Cu2SnS3 with band gap of 0.83 eV is synthesized by non-vacuum mechanochemical method, and is prepared into absorber layer by non-vacuum printing technique. The phoThe scarcity of materials with band gap value of 0.5~0.85 eV is one of the major challenges for the multi-junction solar cells. In this study, the compounds Cu2SnS3 with band gap of 0.83 eV is synthesized by non-vacuum mechanochemical method, and is prepared into absorber layer by non-vacuum printing technique. The photovoltaic properties of the Cu2SnS3 are studied by employing a superstrate solar cell structure of Mo/Cu2SnS3/In2S3/TiO2/FTO glass. Experiment result indicates that the short-circuit current density, open-circuit voltage, fill factor and conversion efficiency of the fabricated solar cell are 12.38 mA/cm2, 320 mV, 0.28% and 1.10%, respectively. Furthermore, to better meet the requirements of multi-junction solar cell on the current matching, the Cu2SnS3/In2S3 p-n junction of the fabricated solar cell is analyzed. A p-n modulation technique with a thin porous buffer layer inserted into the p-n junction interface is proposed. The results indicate that the technique can promote the short-circuit current density of the solar cell from initial 12.38 mA/cm2 to 23.15 mA/cm2, and the corresponding solar cell conversion efficiency from 1.1% to 1.92%. This p-n modulation technique can be an important reference to the printed thin film solar cells..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 1, 13 (2013)
A Method to Modulate Carrier-wave Speckle Pattern Fringe Based on Fringe Center
LIN Zhen-heng
There are noticeable demodulation phase errors for spectrum expanding when the traditional Fourier transform method is used to evaluate the carrier-wave interfergram fringe pattern including multi-protuberances. A new method to modulate carrier-wave speckle pattern fringe based on finge center was proposed. According tThere are noticeable demodulation phase errors for spectrum expanding when the traditional Fourier transform method is used to evaluate the carrier-wave interfergram fringe pattern including multi-protuberances. A new method to modulate carrier-wave speckle pattern fringe based on finge center was proposed. According to the parallel modulation method and gradient modulation method, the corresponding mathematical reasoning of fringe center modulation method was carried out in theory respectively. Then least-square cubic surface fitting algorithm was adopted to evaluate the whole out-of-plane displacement of object surface. Experimental results show that the above-mentioned modulation method and surface fitting method could not only modulate complex carrier-wave fringe pattern, but also obtain alabastrine whole out-of-plane displacement information with sub-pixel location precision and continuum..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 1, 19 (2013)
Hole Injection Layer Effect on Red OLED Performance
AN Tao, NAN Jing-biao, XIA Yan-feng, and GAO Yong
Preparation of high efficiency, high brightness red organic light emitting diode is the key to realize full color display, and high performance red organic light emitting diode device has a great significance for the study. This paper mainly studies the doping agent (DCJTB) concentration on red organic light emitting dPreparation of high efficiency, high brightness red organic light emitting diode is the key to realize full color display, and high performance red organic light emitting diode device has a great significance for the study. This paper mainly studies the doping agent (DCJTB) concentration on red organic light emitting diode performance influence. In the experiment, using vacuum thermal evaporation method, the selection of structure for ITO/2-TNATA(20mm)/NPB(30 nm)/AlQ(50 nm)∶(X%)DCJTB／AlQ(30 nm)／LiF(0.8 nm)／Al(100 nm) red device, the organic thin film function material precise evaporation is realized, in high accuracy film thickness control instrument monitoring. Research shows that: red dopant doping concentration is 2.5%~3.0%, the 12 V voltage can be obtained under luminous intensity to a maximum of 8 900 cd/m2, luminous efficiency is more than 2.8 cd/A, and luminous spectral wavelength for 610~618 nm ideal red organic light emitting diode device..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 1, 24 (2013)
Optical Parametric Gain in the Magneto-optic Nonlinear Fiber
LI Shu-biao, WU Bao-jian, and WEN Feng
The coupled-mode equation for the magneto-optic four-wave mixing existing in a fiber with magneto-optic and nonlinear effects as perturbation is derived. The parametric processes of the isotropic magneto-optical nonlinear fiber are analytically investigated, and the phase matching condition can be achieved by the dispeThe coupled-mode equation for the magneto-optic four-wave mixing existing in a fiber with magneto-optic and nonlinear effects as perturbation is derived. The parametric processes of the isotropic magneto-optical nonlinear fiber are analytically investigated, and the phase matching condition can be achieved by the dispersion characteristics for the magneto-optic coupling coefficient. In the case that the wavelength dependency of fiber Verdet constant is negligible, the magnetic control characteristics of fiber parametric gain are analyzed for the incident left-hand circular polarization. The necessity of using magneto-optic and nonlinear fiber with high Verdet constant in the experiments is pointed out. The results show that, 1) for the magneto-optical nonlinear fiber with low birefringence, the maximal parametric gain can be obtained by optimizing the magnitude of fiber birefringence; 2) from the monotonic dependence of parametric gain on the magneto-optic coupling coefficient, the magnetic adjustability of parametric gain can be improved by appropriately choosing fiber length, pump power and polarization states of guided optical waves..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 1, 29 (2013)
Analysis of Frequency Drift Effects in the Phase-generated Carrier Method
MA Lin, LIU Yan, LI Yang, LIU Zhi-bo, and JIAN Shui-sheng
A rigorous theoretical derivation on the influence of frequency drift of the carrier has been made in this paper. By analyzing the demodulation formula, the influence formula of frequency drift of the carrier was given. The formula shows that when there is a tiny difference between the frequency of modulation and demodA rigorous theoretical derivation on the influence of frequency drift of the carrier has been made in this paper. By analyzing the demodulation formula, the influence formula of frequency drift of the carrier was given. The formula shows that when there is a tiny difference between the frequency of modulation and demodulation signals, the demodulation result will be modulated by a low-frequency signal and the demodulation result will be distorted. Experimental and simulation were carried out on this basis, and the results are completely consistent with the theoretical analysis..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 1, 34 (2013)
Assessment of Performance for All-optical Reshapers Based on the Power Transfer Function
AN Jun-ge, WU Bao-jian, and ZHOU Xing-yu
According to the linearized three-section model of input/output power transfer function (TF), the theoretical assessment method of all-optical reshapers’ performance is investigated and verified by simulation of four-wave-mixing-based scheme. The performance of all-optical reshapers dependent on the input signal of GauAccording to the linearized three-section model of input/output power transfer function (TF), the theoretical assessment method of all-optical reshapers’ performance is investigated and verified by simulation of four-wave-mixing-based scheme. The performance of all-optical reshapers dependent on the input signal of Gaussian distribution is analyzed. The transfer function is divided into five regions from low to high power levels, and a larger improvement of quality factor or BER performance can be obtained for the cases that the average level of mark pulses exists in the fifth region. With the increase of the TF′s second-section slope for a desirable reshaper, the gain saturation of quality factor or BER performance will occur and the extinction ratio will be improved linearly..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 1, 38 (2013)
Gain Switched All-fiberized Pulse Yb Fiber Laser
SUN Hong, WEI Kai-hua, QIAN Kai, CHEN Tao, YANG Ding-zhong, JIANG Pei-pei, WU Bo, and SHEN Yong-hang
A gain-switched Yb-doped pulse fiber laser which was periodically pumped by a pulsed Laser Diode (LD) centering at wavelength of 975 nm was reported. The pulsed Yb fiber laser was composed of a piece of Yb doped double cladding gain fiber and a pair of fiber Bragg gratings. Under pump power of 20 W and pulse duration oA gain-switched Yb-doped pulse fiber laser which was periodically pumped by a pulsed Laser Diode (LD) centering at wavelength of 975 nm was reported. The pulsed Yb fiber laser was composed of a piece of Yb doped double cladding gain fiber and a pair of fiber Bragg gratings. Under pump power of 20 W and pulse duration of 2.4 μs at repetition rate of 50 kHz, stable laser pulse trains were obtained at 1 060 nm with pulse duration of 100 ns. The shot energy of every pulse was measured up to 20 μJ. Using this pulsed Yb fiber laser as the seed, a maser-oscillator power amplifier (MOPA) structured high power Yb laser was constructed with pulse energy exceeding 200 μJ. The slope efficiency of the MOPA was about 60%..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 1, 43 (2013)
Satellite-to-satellite Lidar Imaging Using Reflective Tomography
QU Fu-qi, HU Yi-hua, JIAO Jun-jun, and DONG Bing
Taking satellite-to-satellite lidar imaging as application background, an imaging processing method based on chirped pulse for reflective tomography lidar is presented. In this method, high precision image reconstruction is obtained by extracting projection data of different observation angle and using CBP algorithm. TTaking satellite-to-satellite lidar imaging as application background, an imaging processing method based on chirped pulse for reflective tomography lidar is presented. In this method, high precision image reconstruction is obtained by extracting projection data of different observation angle and using CBP algorithm. The condition of satellite-to-satellite lidar reflective tomography imaging is analyzed, including imaging resolution, working modes and imaging time. The results show that, the mode of accompanying satellite detecting in the same orbit plan meet the requirement of multiple angle detecting for lidar reflective tomography imaging.0.1 meter spacial resolution can be achieved while the range of detecting angle is larger than 60 degree, and the larger the range of angle, the higher the resolution is. The imaging time depends on the satellite orbit radius and the range between two satellites. Imaging experiment validates the feasibility and effectiveness of the presented method..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 1, 48 (2013)
Extrication of Wake Vortex Parameters Based on Lidar Echo
XU Shi-long, HU Yi-hua, and ZHAO Nan-xiang
In order to realize the monitoring of the aircraft wake vortex effectively, solve the puzzles of flight safety and runway capacity limitation, an algorithm of wake vortex parameter extrication based on Lidar echo is proposed. The physical model of circulation and radial velocity distribution is studied, and the structuIn order to realize the monitoring of the aircraft wake vortex effectively, solve the puzzles of flight safety and runway capacity limitation, an algorithm of wake vortex parameter extrication based on Lidar echo is proposed. The physical model of circulation and radial velocity distribution is studied, and the structure of wake vortex is descripted. Based on the features of the vortex parameters, the flowchart of parameter extrication is given, as echo signal processing for noise reduction, threshold selection for velocity envelopes to resolve the velocity distribution and parameter(core radius, core position, circulation) extrication. Moreover, the calculation example of extrication algorithm is carried by taking a certain type of aircraft for example which is compared with the model simulation. The experimental result verifies the effectiveness of the extrication algorithm..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 1, 54 (2013)
Laser Measurement and Reconstruction Method Research for a Kind of Rotary Shell′s Inner-surface with Uncertain Configuration
WANG Fei, LUO Zhong, and LIU Hong-yi
According to configuration uncertainty of a kind of rotary shell′s inner surface, a laser measurement and reconstruction method based on quasi-online longitudinal curve for the inner-surface is proposed in this paper. The whole laser measurement is implemented in virtue of two steps. One is coarse measurement process, According to configuration uncertainty of a kind of rotary shell′s inner surface, a laser measurement and reconstruction method based on quasi-online longitudinal curve for the inner-surface is proposed in this paper. The whole laser measurement is implemented in virtue of two steps. One is coarse measurement process, the other is precise measurement process. In coarse process, the basic information of the rotary shell′s inner-surface is picked up from its technical file. For the uncertainty of the inner-surface′s configuration, a fuzzy prediction algorithm for the actual inner-surface is applied for precise measurement process. The measurement position of inner surface in next sampling time is predicted based on fuzzy reasoning. The measurement is accomplied through adjusting of projecting angle and location of laser sensor depending on the prediction algorithm. The laser experimental platform is set up. Its software system is developed. Experimental research of the proposed method are carried out by means of the test platform. The three-dimensional data are obtained from coarse and precise measurement process. The measurement and reconstruction method is evaluated in terms of secondary processing requirement. The 3D model of the rotary shell′s inner-surface is reconstructed by using appropriate measurement and reconstruction method. The experimental results verify that the proposed method reveals better performance.The mean absolute difference rate of the model is less than 0.024%..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 1, 59 (2013)
Theoretical Studies of Two-dimensional IR Spectroscopy for Traditional Chinese Medicine Cordyceps Sinensis
LIU Xue-yi, and LIANG Xian-ting
Cordyceps sinensis is a kind of precious Chinese herbal medicine that is good for medical treatment and health care. The pharmacological characteristics of this kind of medicine is not based on a single or few kinds of chemical substances but on the whole constituted with all elements. In order to explore the pharmacolCordyceps sinensis is a kind of precious Chinese herbal medicine that is good for medical treatment and health care. The pharmacological characteristics of this kind of medicine is not based on a single or few kinds of chemical substances but on the whole constituted with all elements. In order to explore the pharmacological characteristics, this paper takes the Chinese herbal medicine, cordyceps sinensis as the whole, and the absorption peaks of the one-dimensional linear spectrum of the medicine as normal modes. The Hamiltonian of interaction between laser and cordyceps sinensis is modeled based on assuming the interaction intensity between modes and the size of the dipole moment resulting from laser irradiation. Then the two-dimensional third-order nonlinear laser spectra of the cordyceps sinensis are calculated. The theoretical spectra are adjusted with the experimental ones, thus the level structure, the coupling strength between each normal modes, and the dipole moment of each mode for the cordyceps sinensis can be obtained. This is a new method of the pharmacological researches for the valuable Chinese herbal medicine..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 1, 64 (2013)
Identification and Classification of Near-infrared Spectrum of Adulterated Wine Based on Support Vector Machine
TAN Kun, YE Yuan-yuan, and DU Pei-jun
Although usual chemical methods have more accurate results in detecting the methanol in adulterated wine, they are complex, expensive and requiring rigorous environment condition. A novel identified and classified spectrum of adulterated wine was proposed based on the support vector machine. The spectra of samples wereAlthough usual chemical methods have more accurate results in detecting the methanol in adulterated wine, they are complex, expensive and requiring rigorous environment condition. A novel identified and classified spectrum of adulterated wine was proposed based on the support vector machine. The spectra of samples were measured by the ASD FieldSpec 3 spectrometer; reflection spectra were pretreated and correlation analysis and univariate regression analysis were carried out, so the peaks of methanol spectra as the characteristic bands which is not over shadowed by the ethanol were obtained; the characteristic bands were used to train classification model, the result was obtained. The result shows that, the classification accuracy is 85% while the content of methanol is less than or equal to 3% as the true wine, and the classification accuracy is 97.5% while the content of methanol is less than or equal to 5% as the true wine. So, this method is available and has higher classification accuracy..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 1, 69 (2013)
Development of Miniature CMOS Fiber Optic Spectrometer
SUN Xiao-xiao, HUANG Mei-zhen, and WANG Yang
The biggest advantage of a CMOS area array sensor is that it is less expensive than a CCD sensor. A miniature spectrometer use an area array CMOS sensor MT9M001C12STM as detector was developed. The prototype uses an asymmetric cross Czerny-Turner optical structure. Its photometric accuracy and linearity were investigatThe biggest advantage of a CMOS area array sensor is that it is less expensive than a CCD sensor. A miniature spectrometer use an area array CMOS sensor MT9M001C12STM as detector was developed. The prototype uses an asymmetric cross Czerny-Turner optical structure. Its photometric accuracy and linearity were investigated, and the photometric deviation arise from stray light was analyzed. The elementary performance was tested as follows: wavelength range 380~800 nm, the integration time can be selected from 1 ms to 500 ms according to the light intensity, spectral bandwidth 6 nm , wavelength accuracy ±1 nm, photometric accuracy ±0.03 AU. Results showed that after calibration and nonlinear correction, this CMOS spectrometer is capable for routine fast analysis..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 1, 74 (2013)
Active Compensation Technology of Photoelectric Theodolite Primary Mirror Surface-shape Error
LI Ling-yin, and WANG Yi-fan
Primary mirror surface-shape error bringing flaw to optical system accuracy, which is caused by the pitching of large diameter photoelectric theodolite, is classified to center position error, off-center error and gravity deformation error. Previous design methods mostly are based on passive compensation, that is, desiPrimary mirror surface-shape error bringing flaw to optical system accuracy, which is caused by the pitching of large diameter photoelectric theodolite, is classified to center position error, off-center error and gravity deformation error. Previous design methods mostly are based on passive compensation, that is, design rational support and prevent deformation measures to assure the primary mirror surface-shape error within the design specifications. In this paper, piezoelectric ceramic active compensation technology is used to revise primary mirror surface-shape error with the method of real time correction on the surface-shape error induced by the pitching for large diameter photoelectric theodolite. Simulation software is utilized to fit the PV and RMS before and after compensation. The max PV value and max RMS decrease to 66.9 nm and 12.9 nm, respectively. Piezoelectric ceramic active compensation technology could bring benefit to image definition quality and the visual axis stability, making contribution to primary mirror surface-shape error on assembly and dynamic detection..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 1, 79 (2013)
Mechanism and Application of Phase Shift in the Polarized Optical Systems
WU Jin-cai, HE Zhi-ping, SHU Rong, JIA Jian-jun, CHEN Shuang, and WANG Jian-yu
In order to realize free space quantum key distribution, an optical system with the property of retaining the polarization state is customized to reduce the quantum bit error rate, and the mechanism and application of phase shift in polarized optical system is investigated. Firstly, based on the principle of matrix optIn order to realize free space quantum key distribution, an optical system with the property of retaining the polarization state is customized to reduce the quantum bit error rate, and the mechanism and application of phase shift in polarized optical system is investigated. Firstly, based on the principle of matrix optics, the relationship among azimuth angle, phase shift and extinction ratio of polarized light is presented. Then the principle of phase shift added linearly is validated in the theorem and experiments. Based on the principle of phase shift added linearly, a set of polarization keeping system is designed and validated in the theorem and experiments，and the principle is applied to design optical systems for quantum communication successfully. Experimental results indicate that the extinction ratio of polarized light of optical systems for quantum communication exceed 500:1. It can satisfy the system requirements of quantum bit error rate for quantum communication..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 1, 84 (2013)
Z-domain Design of Polarization-independent Birefringent Multi-wavelength Filter
[in Chinese], and [in Chinese]
A polarization-independent two-port wave-guided multi-wavelength tunable fiter is designed based on the electro-optic effect of birefringent Lithium Niobate (LiNbO3) crystal. Mode-coupled electrode and phase-shifted electrode periodically alternated cascaded are set on each arm of an asymmetric interferometer to realizA polarization-independent two-port wave-guided multi-wavelength tunable fiter is designed based on the electro-optic effect of birefringent Lithium Niobate (LiNbO3) crystal. Mode-coupled electrode and phase-shifted electrode periodically alternated cascaded are set on each arm of an asymmetric interferometer to realize mode conversion. Z-domain analysis of Jones matrix is utilized to get the values of driving voltages so that wavelengths can be selected simultaneous. Narrow-band multi-wavelength with arbitrary distribution is simulated successfully in Free Spectrum Range (FSR). 100% transmittance is obtained at each wavelength. Number of wavlengths has an influence on sidelobe of each wavelength. And sidelobe of 12 dB can be realized when three wavelengths are selected. Comb filter can also be obtained using this method, which has a flat passband and sidelobe of more than 15 dB..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 1, 90 (2013)
Comparison and Research of Zoom Curve Fitting Methods
GAO Tian-yuan, and HOU Zhen-yan
In mechanical compensation zoom optical system, the zoom can be achieved through the zoom curve to control the movement of the zoom group and the compensation group. Therefore, it is very necessary to fit a good zoom curve to make the imaging of zoom optical system clear and stable during the zoom process. In this papeIn mechanical compensation zoom optical system, the zoom can be achieved through the zoom curve to control the movement of the zoom group and the compensation group. Therefore, it is very necessary to fit a good zoom curve to make the imaging of zoom optical system clear and stable during the zoom process. In this paper, the dynamic optical theory, CODE V and ZEMAX macro are used individually to fit zoom curve for a 20× zoom optical system, then the corresponding movement curve equations can be generated. According to the three groups of curve equations, several random zoom position points are selected and evaluated in defocus and MTF of central field and edge field. Through the analysis of the data, the zoom curve fitted by the dynamic optical theory can meet the system requirements, and it is better to ensure the image plane stable..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 1, 94 (2013)
Grid Feature and Visualizition for Occlusion Perception in Object Tracking
MENG Bo, HAN Guang-liang, and MAO Wen-bei
A grid-based histogram of the orientation gradient feature and visualization techinique were used in object tracking algorithm to solve the problem of tracking objects moving in surveillance video. The histogram of orientation gradient based on grid was designed as the local feature to describe the object. And it can aA grid-based histogram of the orientation gradient feature and visualization techinique were used in object tracking algorithm to solve the problem of tracking objects moving in surveillance video. The histogram of orientation gradient based on grid was designed as the local feature to describe the object. And it can apperceive the abnormalities of objects such as occlusion, disturbance and deformation etc. The visualization was used to real-time observe the changes of the characteistics through the changes of the local feature. The weights of the sub-model was adjusted adaptively to keep the stability of the tracking algorithm. The experimental results show that the proposed local feature can perceive the abnormity correctly, and can impove the robustness and stability of the tracking algorithm. The self-perception matching algorithm based on this local feature can tracking object accurately and stably in surveillance video..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 1, 98 (2013)
Color Matching of Color Computer-generated Holography
SHI Yi-le, WANG Hui, WU Qiong, LI Yong, and JIN Hong-zhen
Color matching issue of (Color Computer-generated Holography, CCGH) is researched based on colorimetric principle. The conversion between color quantity in electronic display colorimetric system and amplitude of object light in CCGH colorimetric system is given. Firstly, the conversion between color quantities in electColor matching issue of (Color Computer-generated Holography, CCGH) is researched based on colorimetric principle. The conversion between color quantity in electronic display colorimetric system and amplitude of object light in CCGH colorimetric system is given. Firstly, the conversion between color quantities in electronic display and CCGH colorimetric system is discussed. Then, the conversion method for color quantity in the two colorimetric systems is given. Secondly, isochromatic transfer relationship of color quantity and amplitude of object light field is proposed. Thirdly, we chose a color image from PAL-RGB colorimetric system as an experimental object of CCGH. The experimental results demonstrate that our novel approach is feasible. The research of this paper will provide theoretical and technical basis for practical use of CCGH..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 1, 104 (2013)
Objective Evaluation Method for Image Quality Based on Edge Structure Similarity
TIAN Hao-nan, and LI Su-mei
In the image-processing area, accurate evaluation of the processed quality is a key technique. In this paper, a new method using image edge combined with structural similariy,whichtakes the importanceof the edge information to eye perception structure into account, is presented. The objective indexes of experimental imIn the image-processing area, accurate evaluation of the processed quality is a key technique. In this paper, a new method using image edge combined with structural similariy,whichtakes the importanceof the edge information to eye perception structure into account, is presented. The objective indexes of experimental images are extracted and calculated， and the experimental data are statistical analysed.The results show that, the new method is better than the structural similarity image quality assessment method and is better fit with the subjective feeling of human visual perception..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 1, 110 (2013)
Adaptive Image Fusion Algorithm Based on Shearlet Transform
SHI Zhi, ZHANG Zhuo, and YUE Yan-gang
For the imaging characteristics of multi-focus images, multi-spectral images and panchromatic images, since the Shearlet transform has better properties to sparse express the characteristics of the images, a kind of new image fusion rules is proposed. Moreover, based on the fusion rules, the algorithm of adaptive fusioFor the imaging characteristics of multi-focus images, multi-spectral images and panchromatic images, since the Shearlet transform has better properties to sparse express the characteristics of the images, a kind of new image fusion rules is proposed. Moreover, based on the fusion rules, the algorithm of adaptive fusion rules based on Shearlet transform is proposed. In the algorithm of multi-focus images fusion, the different focus images are transformed with Shearlet transform respectively, and the decomposed low-frequency coefficients and high-frequency coefficients were fused according to the proposed fusion rules. It is verified that the proposed algorithm has better clarity and richer details information compared with many algorithms. Multi-spectral and panchromatic images fusion algorithm is proposed based on combination of Shearlet and HSV transform. Firstly, the multi image is transformed with HSV transform; then, the gotten V component is Shearlet transformed with pan image and the specific fusion rules is chosen for the decomposition coefficient in the fusion process; finally, the new V and H,S components are transformed with inverse HSV transform. This algorithm reached a good balance in the two aspects of spatial resolution and spectral characteristics. The fused images can reduce spectral distortion, and effectively enhance the spatial resolution. The simulation experiments show that the proposed algorithm has better fusion performance and visual effect, compared to traditional multi-spectral and panchromatic images fusion algorithms..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 1, 115 (2013)
Image Joint Compression-encryption Algorithm Based on Improved Zero-tree Coding
DENG Jia-xian, and REN Yu-li
On the basis of careful research on arithmetic coding and arithmetic encryption, a kind of image joint compression encryption algorithm based on improved zero-tree coding is proposed, where a key is used to modify the original context and the original decision produced in the process of image compression, and the imageOn the basis of careful research on arithmetic coding and arithmetic encryption, a kind of image joint compression encryption algorithm based on improved zero-tree coding is proposed, where a key is used to modify the original context and the original decision produced in the process of image compression, and the image joint compression-encryption is realized in this way. In this work, the rule of the context modification and the decision modification algorithm is discussed and its security is analyzed. In order to meet different application requirements, different keys are used to encrypt separately the different wavelet resolution coefficients during bit-plane coding, so the resolution selective encryption is realized. Moreover, the Zero-tree coding was improved, and adaptive arithmetic coding is introduced to the improved Zero-tree coding, and then joint compression-encryption algorithm proposed is simulated. The simulation results show that the proposed image joint compression-encryption algorithm has the same compression efficiency compared with the original image compression algorithm; and the proposed algorithm has better security than the joint compression-encryption algorithm based on the interval splitting..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 42, Issue 1, 121 (2013)
© Copyright 2018-2021 | Chinese Laser Press. All Rights Reserved 沪ICP备15018463号-20