Journals >Acta Photonica Sinica
Contents
2009
Volume: 38 Issue 8
58 Article(s)
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Research Article
SHEN-GUANG III Core X-ray Framing Cameras
CAO Zhu-Rong, LIU Shen-Ye, ZHANG Hai-Ying, DING Yong-Kun, BAI Yong-Lin, ZHAO Jun-Ping, LIU Bai-Yu, and BAI Xiao-Hong
The XFC system was designed to record time-dependent X-ray emission from SGIII targets using an interchangeable family of snouts for measurements such as two-dimensional spatially or one-dimensional spectrally time resolved images of target features. The SGIII core XFC were designed to fit within an aluminum air-box wiThe XFC system was designed to record time-dependent X-ray emission from SGIII targets using an interchangeable family of snouts for measurements such as two-dimensional spatially or one-dimensional spectrally time resolved images of target features. The SGIII core XFC were designed to fit within an aluminum air-box with a large capacity cooling plane and were fitted with an array of environmental-keeping sensors. These designs of the instrument are different from earlier generations of XFC, in part, to an innovative impedance matching scheme, temporal window adjustable of 0.07~1.5 ns, advanced phosphor screens, pulsed phosphor circuits, precision assembly fixture, unique system monitoring, and complete remote computer control. The preliminary applications of advanced phosphor screens and pulsed phosphor circuits was given..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 1881 (2009)
Spectral Shifts and Spectral Switches of Femtosecond Optical Pulses in Young′s Interference Experiment
DING Chao-liang, LV Bai-da, and PAN Liu-zhan
Starting from the Huygens-Fresnel diffraction integral,the spectral shifts and spectral switches of femtosecond optical pulses in Young′s interference experiment are studied and analyzed numerically.It is shown that the spectral shifts and spectral switches,which take place in Young′s interference experiment,depend on Starting from the Huygens-Fresnel diffraction integral,the spectral shifts and spectral switches of femtosecond optical pulses in Young′s interference experiment are studied and analyzed numerically.It is shown that the spectral shifts and spectral switches,which take place in Young′s interference experiment,depend on the pulse width,carrier frequency,obscuration ratio and the position of field points in general.The number of the spectral switches decreases with decreasing obscuration ratio,and the relative spectral shifts at the spectral switches increases with decreasing carrier frequency and pulse width.The spectral switches studied in this paper belong to the phenomenon of singular optics because the minimum at the spectral switches Smin=0.The information encoding and transmission can be achieved by a suitable variation of the obscuration ratio..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 1886 (2009)
Transmissivity for Narrowband Filter in Omni-directionalLaser Warning System
YING Jia-ju, WANG Yong-zhong, HE Yong-qiang, ZHOU BING, and ZHOU Zhongliang
Based on analyzing the structure of omni-directional laser warning system,the contradiction between wide field of view and the narrow-band spectrum filter is expounded.The Fabry-Perot model is set up. And the transmissivity of the filter vary to different incident angle is analyzed from the factors such as reflectivityBased on analyzing the structure of omni-directional laser warning system,the contradiction between wide field of view and the narrow-band spectrum filter is expounded.The Fabry-Perot model is set up. And the transmissivity of the filter vary to different incident angle is analyzed from the factors such as reflectivity of the reflective coating,phase jump and optical path difference.The relationship formula of incident angle and the transmissivity is given out, and its validity is verified by experiment..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 1892 (2009)
Improvement of Detecting SNR of Laser Radar by Time-Delay Superimposition
JIANG Hai-jiao, LAI Jian-cheng, WANG Chun-yong, BIAN Bao-min, and LI Zhen-hua
A new method of by time-delay superimposition was developed which could effectively improve the detecting signal-noise-rate of laser radar on the basis of spectral characteristic analysis.A larger number of laser radar echo signal was obtain by experiment.And the practicability of using time-delay superimposition to imA new method of by time-delay superimposition was developed which could effectively improve the detecting signal-noise-rate of laser radar on the basis of spectral characteristic analysis.A larger number of laser radar echo signal was obtain by experiment.And the practicability of using time-delay superimposition to improve the detecting signal-noise-rate of laser radar was discussed on the basis of it.The results show that on the condition of 50 MHz system bandwidth and 30 ns impulse width of echo wave,time-delay superimposition could improve the detecting SNR of Laser radar more than 40%.Also the optimally time also was existence..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 1897 (2009)
Time Sharing Scanning Multiplexing Method of Tunable DiodeLaser Spectroscopy System
CHEN Dong, LIU Wen-Qing, and ZHANG Yu-Jun
For the demand of multiply gas species detection of tunable diode laser spectroscopy, a novel time-division multiplexing method-time sharing scanning multiplexing method is presented.Based on the wavelength modulation spectroscopy technology, quasi-simultaneously multi-species detection in one system cycle is realized For the demand of multiply gas species detection of tunable diode laser spectroscopy, a novel time-division multiplexing method-time sharing scanning multiplexing method is presented.Based on the wavelength modulation spectroscopy technology, quasi-simultaneously multi-species detection in one system cycle is realized by simultaneous modulating and sequencially scanning multiply lasers. This method is used in infrared laser spectroscopy based gas emission multi-component detection system.Through Quasi-simultaneously detection of CH4 and H2S concentrations, the possible gas emission monitoring is guaranteed.At the precondition of sufficient sensing sensation, the system configuration is simplified..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 1901 (2009)
Demodulation Fiber Bragg Grating Acceleration Sensor by DFB Laser
HUO Dian-heng, CHANG Jun, LIU Tong-yu, MA Liang-zhu, and LIU Xiao-hui
A FBG accelerometer as a sensor of oscillation system demodulated by DFB laser is demonstrated.The working principle and system constitution are presented.The cantilever packaging scheme is also designed to enhance the sensitivity of the FBG sensor. The sensor's response to frequency and acceleration is measured byA FBG accelerometer as a sensor of oscillation system demodulated by DFB laser is demonstrated.The working principle and system constitution are presented.The cantilever packaging scheme is also designed to enhance the sensitivity of the FBG sensor. The sensor's response to frequency and acceleration is measured by experiment.It is shown that the heavier the mass which attached to the cantilever is, the higher sensitivity of the sensor will be,but this will result in the lower resonate frequency.Relationship between resonance suppression and viscosity of silicone oil given and discussion about the sensor's sensitivity and wavelength of DFB laser is carried out..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 1906 (2009)
Influence of Grid Gated Pulse Edge on Streak Tube′s Characters
CHEN Zheng-kai, LI Li-zhou, TIAN Jin-shou, LIU Hu-lin, and XU Xiang-yan
Based on a 5.0 ps time resolved streak tube with length of 189.472 mm, the influence of grid gated impulse on the characters of the streak tube was discussed. It is found that the rising edge and falling edge of the gated impulse would deteriorate both temporal and spatial resolution capabilities of the streak tube. ThBased on a 5.0 ps time resolved streak tube with length of 189.472 mm, the influence of grid gated impulse on the characters of the streak tube was discussed. It is found that the rising edge and falling edge of the gated impulse would deteriorate both temporal and spatial resolution capabilities of the streak tube. The spatial resolution may fall sharply to half when the voltage on grid has a fluctuation of 10%. The main cause for the destructive influence is that optimal imaging position shifts when the voltage on grid changes. Influence on temporal and spatial resolution would reinforce as the deviation of voltage on grid increases. In conclusion, the rising and falling edge of gated impulse on grid gated impulse should be controlled strictly in narrow to reduce the impairment on the streak tube..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 1910 (2009)
Switching Characteristics of a 1×N Electro-optic PolymerMicroring Resonator Switch Array
YAN Xin, MA Chun-sheng, CHEN Hong-qi, ZHENG Chuan-tao, WANG Xian-yin, and ZHANG Da-ming
In terms of the coupled mode theory, microring resonance theory and electro-optic modulation theory, a reasonable project is proposed for designing an electro-optic polymer microring resonator switch array. This device consists of 1 horizontal channel, N vertical channels and N microrings. By applying different mannersIn terms of the coupled mode theory, microring resonance theory and electro-optic modulation theory, a reasonable project is proposed for designing an electro-optic polymer microring resonator switch array. This device consists of 1 horizontal channel, N vertical channels and N microrings. By applying different manners of the operation voltage on the microrings, the switching functions can be realized in the N+1 channels. Taking 1×8 channels as an example, the optimization and simulation are performed under the resonant wavelength of 1550 nm. The results are as follows: the core size of the microring is 1.7×1.7 μm2, the buffer layer thickness between the core and the electrode is 2.5 μm, the electrode thickness is 0.2 μm, the microring radius is 13.76 μm, the coupling gap between the micoring and the channel is 0.14 μm, the 3-dB bandwidth of the output spectrum is about 0.05 nm, the switching voltage is about 12.6 V, the insertion loss is about 0.67~1.26 dB, and the crosstalk is less than -20 dB, and the switching time is about 11.35 ps..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 1914 (2009)
Effective Diffraction Region for Satellite Retroreflector
ZHOU Hui, LI Song, ZHENG Guo-xing, GAO Jun-ling, and HAN chun-jun
Based on geometrical structure of retroreflector and vector form of reflection-refraction law, a mathematical model with EDR is built up for retroreflector.By the means of numerical simulation, the regularity of change for EDR and the impaction of regularity on far field diffraction intensity (FFDI) are analysed. The sBased on geometrical structure of retroreflector and vector form of reflection-refraction law, a mathematical model with EDR is built up for retroreflector.By the means of numerical simulation, the regularity of change for EDR and the impaction of regularity on far field diffraction intensity (FFDI) are analysed. The simulated results show that EDR decreases with the increase of the divergence of FFDI with laser incidence angle.But,laser amuzith has no impact on shape of EDR and total diffraction intensity,which only makes their distributions rotate amuzith angle. When atmospheric effects are ignored,In terms of FFDI distribution with different incidence condition and velocity aberration theory, the new way for designing retroreflector radius is put forward.The investigation of EDR provides important approach to calculate FFDI and design satellite retroreflector..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 1920 (2009)
Grating Light Valve′s Structure Improvement and Its Manufacture Technology
ZHANG Wei, GENG Yu, HOU Chang-lun, and YANG Guo-guang
A grating light valve′s structure improvement is proposed based on its working principle.The optical characteristics,structure characteristics and fabrication technology of the improved grating light valve are analyzed.In the improved structure,silicon dioxide layer is on silicon substrate as isolation layer and amorphA grating light valve′s structure improvement is proposed based on its working principle.The optical characteristics,structure characteristics and fabrication technology of the improved grating light valve are analyzed.In the improved structure,silicon dioxide layer is on silicon substrate as isolation layer and amorphous silicon is deposited on silicon dioxide layer as sacrificial layer.Movable ribbon′s material is silicon nitride and fixed ribbon′s is aluminium film.After ion etching and chemical etching,the structure of bridge-like shape is got.Through study,satisfactory results were obtained including small black area,low driving voltage and high optical intensity,and this kind of grating light valve has potential future in application..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 1926 (2009)
3-D Noise Measurement and Analysis for a Double Proximity Focusing X-ray Image Intensifier Radiography Imaging System
LI Wei, ZHAO Bao-sheng, ZHANG Xing-hua, ZHAO Fei-fei, ZHANG Rui-li, and LI Han-zhi
A double proximity focusing X-ray image intensifier radiography imaging system was made as an experimental object.A new method was used for measuring and analyzing 3-D noise of this system.By analyzing 3-D noise of this system,the distribution of noise both in time field and frequent field with curves of three dimentioA double proximity focusing X-ray image intensifier radiography imaging system was made as an experimental object.A new method was used for measuring and analyzing 3-D noise of this system.By analyzing 3-D noise of this system,the distribution of noise both in time field and frequent field with curves of three dimentions was drawn.The 3-D noise of a double proximity focusing X-ray image intensifier radiography imaging system was measured and analyzed under four different conditions with the help of digital image processing technology.The result of measurement and analysis agrees well with the performance of the two side proximity of X-ray image intensifier radiography imaging system..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 1932 (2009)
Effect of the LP-MOCVD Growth Parameters For Type-Ⅱ InAs/GaSb Superlattices Surface Morphology
WU Lei-xue, WANG Tao, WANG Jing-wei, LI Xiao-ting, JING Zheng, YIN Fei, and MEI Shu-gang
Type-Ⅱ InAs/GaSb superlattices materials were grown on (100) GaSb substrate in a horizontal quartz reactor by a home-made low pressure metal organic chemical vapor deposition (LP-MOCVD).Growth surface structures and morphologies were characterized by means of double crystal X-ray diffraction (DCXRD),atomic force microsType-Ⅱ InAs/GaSb superlattices materials were grown on (100) GaSb substrate in a horizontal quartz reactor by a home-made low pressure metal organic chemical vapor deposition (LP-MOCVD).Growth surface structures and morphologies were characterized by means of double crystal X-ray diffraction (DCXRD),atomic force microscopy (AFM) and photo-luminescence (PL).High quality mirror-like surfaces type-Ⅱ InAs/GaSb superlattices materials were obtained.Photoluminescence results show that the peak wavelength of the type-Ⅱ InAs/GaSb superlattices at 77 K is 3.25 μm.The effects of growth temperature,buffer layer and interfacial layer for surface morphology were discussed.The condition that growth temperature in 500 ℃~520 ℃,without buffer layer and InAsSb interfacial layer can improve the surface morphology of the material..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 1937 (2009)
Research on Arbitrary Electrical Pulse Generation Technology for Laser Pulse Shaping*
LI Xiao-kun, LIU Bai-yu, OU-YANG xian, BAI Yong-lin, DANG Jun-li, SHU Ya, XIONG Fa-tian, and LEI Juan
To realize intelligently adjustable pulse-shaping, a computer was used to control the gate bias of each GaAs filed-effect transistor (FET) and superpose pulses generated by them. To improve the stability and reduce the trigger jitter of shaped-pulse, the pulse shaping circuit was properly designed. 1~5 V adjustable ampTo realize intelligently adjustable pulse-shaping, a computer was used to control the gate bias of each GaAs filed-effect transistor (FET) and superpose pulses generated by them. To improve the stability and reduce the trigger jitter of shaped-pulse, the pulse shaping circuit was properly designed. 1~5 V adjustable amplitude, 0~3 ns square wave width, rising edge 250 ps falling edge 350 ps, 4% (peak to peak) amplitude stability, and 200 ps time domain adjustment precision were obtained..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 1942 (2009)
Reflection Phase Properties in the Omni-directional Gap of One-dimensionalPhotonic Crystals with Mu-negative or Double-negative Materials
LIN Mi, OU-YANG Zheng-biao, and XU Jun
Reflection phase properties of one-dimensional photonic crystals (PhCs) with mu-negative or double-negative materials are investigated by the transfer matrix method. In both of the two structures-“mu-negative positive-index PhC” and “double-negative positive-index PhC”, the results show that the reflection phase in theReflection phase properties of one-dimensional photonic crystals (PhCs) with mu-negative or double-negative materials are investigated by the transfer matrix method. In both of the two structures-“mu-negative positive-index PhC” and “double-negative positive-index PhC”, the results show that the reflection phase in the omni-directional gap increases with the increase of incident angle for TE modes. For TM modes, the reflection phase decreases with the increase of incident angle. And the reflection phase increases with the increase of the scaling factor of layer thickness, while keeps invariant with the increase of periodic numbers for both TE and TM modes..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 1946 (2009)
Experimental Study of Zero-average Refractive Index (Zero-n－) Gaps Based on Microstrip Transmission Lines
ZHANG Li-wei, DU Gui-qiang, XU Ji-ping, WANG Zhi-guo, and ZHANG Ye-wen
One-dimensional photonic crystals composed of left-handed and right-handed materials are fabricated by using transmission lines (TLs) approach.The transmission properties of the photonic crystals are simulated by the advanced design system (ADS) of Agilent and measured by the vector network analyser.The results indicatOne-dimensional photonic crystals composed of left-handed and right-handed materials are fabricated by using transmission lines (TLs) approach.The transmission properties of the photonic crystals are simulated by the advanced design system (ADS) of Agilent and measured by the vector network analyser.The results indicate that the photonic crystals possess zero-n－gap which exists between the left-handed passband and right-handed passband.The special gap edges are determined by zero average permittivity ε－=0and zero average permeability μ－=0respectively,so it is insensitive to the scale length..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 1953 (2009)
Investigation on Two-dimensional Photonic Crystal Asymmetric Mach-Zehnder Self-collimation Sensor
WANG Yu-fei, QIU Yi-shen, CHEN Xi-yao, QIANG Ze-xuan, LAI Guo-zhong, and QIU Hui-ye
A new asymmetric Mach-Zehnder interferometer sensor is proposed based on the self-collimation effect of two-dimensional air-cylinder photonic crystal by introducing a sensing area in the longer branch.Self-collimation frequency range is confirmed by employing the plane wave expansion method.Two-dimensional finite-diffeA new asymmetric Mach-Zehnder interferometer sensor is proposed based on the self-collimation effect of two-dimensional air-cylinder photonic crystal by introducing a sensing area in the longer branch.Self-collimation frequency range is confirmed by employing the plane wave expansion method.Two-dimensional finite-difference time-domain technique is used in this work.68 nm/RIU sensitivity can be achieved.The simulated performance is realized by the incidence of single frequency light.The proposed photonic crystal sensor is defect free configuration and thus reduce the fabrication difficulty.The dimensions of such sensor are no more than twenty microns.It is desirable to perform ultra-compact,highly-sensitive,low-cost label-free sensor and may be applied to photonic integrated circuits..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 1958 (2009)
Design of Automatism Etching for Fabricating Fiber Probes of Scanning Near-field Optical Microscope
YANG Yong-bin, XU Wen-dong, and LUO Ji-quan
A design of automatism etching for fabricating the fiber probe of scanning near-field optical microscope is proposed.Probes of various structures,such as sharp tip and large cone angle or multi-taper,can be formed by using the special structure formed in the static etching process and the change of the contact positionA design of automatism etching for fabricating the fiber probe of scanning near-field optical microscope is proposed.Probes of various structures,such as sharp tip and large cone angle or multi-taper,can be formed by using the special structure formed in the static etching process and the change of the contact position of meniscus on the fiber surface caused by the fiber′s movement in the dynamic etching process,and controlling the time of etching.The automatism of fabricating the probe is realized by controlling the whole equipment with the computer in this design,so that the experimental conditions of forming fiber probe are the same.The experimental results show that fiber probes with 70° cone angle can be fabricated,which is under 100nm.And,the fiber probes with high repeatability and different configuration can be obtained by using this design,so that different requirements can be satisfied.In addition,the configuration of the design is very simple and can be actualized easily..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 1962 (2009)
Imaging Analysis of Optical Sparse Aperture Systems With Different Multiple-array Configuration Design
ZHAO Juan, WANG Da-yong, WAN Yu-hong, JIANG Zhu-qing, and TAO Shi-quan
Based on the traditional array configuration, including the annulus, Golay-6 and the Tri-arm, two ways for designing multiple-array configurations are investigated. Then the simulation with the multiple-array configurations are fulfilled with the specific system parameters. The direct imaging results and the restored iBased on the traditional array configuration, including the annulus, Golay-6 and the Tri-arm, two ways for designing multiple-array configurations are investigated. Then the simulation with the multiple-array configurations are fulfilled with the specific system parameters. The direct imaging results and the restored images are obtained. By using the correlation coefficient as the evaluation criterion of imaging, the results show that different designs of the multiple-array configurations may produce the different quality of the imaging. It should consider the characteristics of the main-array to choose its sub-array configuration and to optimize the array..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 1967 (2009)
Compensation for the Quadratic Phase Aberration in Off-axis Digital Micro-holography
ZHOU Wen-jing, XU Qiang-sheng, and YU Ying-jie
A new method is presented to compensate the quadratic phase aberration introduced by Micro-Objective (MO) in Pre-magnified off-axis Digital Micro-Holography(DMH). It can realize the numerical compensation for the quadratic phase aberration on the back focal plane of the MO. By using this method, one parameter only needA new method is presented to compensate the quadratic phase aberration introduced by Micro-Objective (MO) in Pre-magnified off-axis Digital Micro-Holography(DMH). It can realize the numerical compensation for the quadratic phase aberration on the back focal plane of the MO. By using this method, one parameter only need to be adjusted numerically to compensate the phase aberration and also only one hologram is needed.And, the auto-calculation for the reconstruction distance is performed in term of the spectrum information characteristic of back focal plane of MO.The experimental example is presented with a phase grating used as a testing specimen. The experimental results validate the presented numerical compensation method right and validity. Some experimental conclusion and analysis are also given at last..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 1972 (2009)
A Novel Optical Soliton Compression Method Based on Step-Like Nonlinearity Profiled Fiber
JIA Dong-fang, LIU Yang, LI Ya-bin, ZHOU Hao, WANG Zhao-ying, and LI Shi-chen
A novel optical soliton compression technique based on step-like nonlinearity profiled fiber is proposed. The step-like nonlinearity profiled fiber is composed of single mode fiber (SMF), dispersion-shifted fiber (DSF) and high nonlinear fiber (HNLF). All the components used in the simulation are available in reality. A novel optical soliton compression technique based on step-like nonlinearity profiled fiber is proposed. The step-like nonlinearity profiled fiber is composed of single mode fiber (SMF), dispersion-shifted fiber (DSF) and high nonlinear fiber (HNLF). All the components used in the simulation are available in reality. Compared with other soliton compression techniques, this method is easy to control and its cost is low also. It is shown in numerical simulation that a hyperbolic secant pulse, whose width is 12.5 ps and peak power is 300mW, can be compressed to a 1.28 ps-width, 1.3 W-peak power pulse by using this step-like nonlinearity profiled fiber transmission line..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 1977 (2009)
Influence of Noise on the Propagation Character of Femtosecond Pulse in Photonic Crystal Fiber
CHEN Chun-ying, ZHANG Jing-gui, WEN Jian-guo, and WEN Shuang-chun
Using linear stability analysis and the standard split-step Fourier method, the influence of noise on the propagation character of femtosecond pulse and the generation of supercontinuum spectrum were studied in photonic crystal fibers with two zero dispersion wavelengths according to nonlinear Schrdinger equation.The Using linear stability analysis and the standard split-step Fourier method, the influence of noise on the propagation character of femtosecond pulse and the generation of supercontinuum spectrum were studied in photonic crystal fibers with two zero dispersion wavelengths according to nonlinear Schrdinger equation.The results show that the initial spectral broadening is mainly due to SPM whatever there has noise or not,but noise increases the speed of the breakup of pulse. Comparing with no noise, dispersive waves appear in a shorter propagation distance. Higher-order soliton splits into many fundamental solitons in the later propagation, and the noise weakens the walk-off effect of soliton,and suppresses the soliton self-frequency shift. So the moving of the pulse energy of the anomalous dispersion regime into the longer wavelength becomes weakly..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 1981 (2009)
Highly Confined Channel Structure of the Surface Plasmon
CHEN Xian, HAO Yin-lei, WANG Ming-hua, YANG Jian-yi, and JIANG Xiao-qing
Based on the surface plasmon physical mechanism,a 2-dimension sub-wavelength channel structure with high confinement factor was presented,Whose size was both sub-wavelengh in 2-dimension,and the power was mainly confined in the core section.Power confinement factor was as high as 98.5 percent when the core cross sectioBased on the surface plasmon physical mechanism,a 2-dimension sub-wavelength channel structure with high confinement factor was presented,Whose size was both sub-wavelengh in 2-dimension,and the power was mainly confined in the core section.Power confinement factor was as high as 98.5 percent when the core cross section was 200 nm×800 nm.,and the lateral mode size was almost equal to the width of the core section.If the height of the metal wall was larger than the cut-off height,the lateral mode size could be deep subwavelength.The Ex field component of the fundamental mode was confined in the core section,the Ey field component only exists at the four angles formed by the metal and dielectric,being antisymmetric with respect to x and y axes..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 1986 (2009)
Optimization of Finite-size Effects in Coupled Microring Resonator Optical Waveguide
XU Yu-feng, HUANG Hui, HUANG Yong-qing, CHEN Hai-bo, and Ren Xiao-min
The finite-size effects in Coupled Microring Resonator Optical Waveguide (CMROW) are investigated.The transmission and normalized group delay are optimized by inserting antireflection structures in both ends of CMROW.The fit formulas of optimized cross-coupling coefficients in antireflection structures are obtained forThe finite-size effects in Coupled Microring Resonator Optical Waveguide (CMROW) are investigated.The transmission and normalized group delay are optimized by inserting antireflection structures in both ends of CMROW.The fit formulas of optimized cross-coupling coefficients in antireflection structures are obtained for both weak coupling and strong coupling.With the fit formulas,the suitable cross-coupling coefficients can be calculated directly and easily.The simulation results show that,optimization can be well realized with the fit formulas..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 1991 (2009)
Aberration Compensation for Telescope Objective System with Reversing Prism Using Binary Optical Element
DU Guang-qing, ZHANG Xiao-lin, ZHAO Xiao-xia, JING Bo, and XIE Yong-jun
The aberration compensation between binary optical len and reversing prism of the hybrid telescope objective is analyzed under the guidance of aberration theory.Phase coefficients of the binary optical element are calculated.Primary configuration of telescope objective with reversing prism is ascertained. The optimizedThe aberration compensation between binary optical len and reversing prism of the hybrid telescope objective is analyzed under the guidance of aberration theory.Phase coefficients of the binary optical element are calculated.Primary configuration of telescope objective with reversing prism is ascertained. The optimized aberration results show that chromatic aberration is rectified exactly at 0.9 relative pupil height;and maximal longitudinal spherical aberration is within range of tolerance 0.5 mm and maximal transverse ray aberration value is -0.115 mm.The MIF with aberration Compensation has been improved largely than the one without aberration compensation..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 1996 (2009)
Effect of Parasitic light of Liquid Crystal Wavefront Correctors on the Accuracy of Wavefront Sensing in the Closed Loop Process
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Effects of liquid crystal molecules alignment on the detection of Shack-Hartmann wavefront sensor and closed loop correction are investigated.The effect of molecule alignment on the intensity of parasitic light is analyzed.The effect of parasitic light on detection and correction accuracy was specially discussed among Effects of liquid crystal molecules alignment on the detection of Shack-Hartmann wavefront sensor and closed loop correction are investigated.The effect of molecule alignment on the intensity of parasitic light is analyzed.The effect of parasitic light on detection and correction accuracy was specially discussed among the closed loop correction. With the ratio of parasitic light of 40%, the detection deviation error is 0.4; while the ratio of parasitic light is 8%, the deviation error just have 0.08, and it may be neglected. And the closed loop correction of static distortion was individually done with twisted and parallel alignment LC WFC. To the twisted alignment, PV and RMS were changed from 1.11 μm and 0.25 μm to 1.08 μm and 0.24 μm. It indicates that the parasitic light causes the serious effect on the closed loop correction. For parallel alignment, with the closed loop correction, PV and RMS are reduced from 1.58 μm and 0.22 μm to 0.095 μm and 0.03 μm respectively, and the resolvable image of the fiber bundle is also achieved. The results show that, if the intensity of parasitic light is lower than 8%, high correction accuracy can be obtained..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2001 (2009)
Anomalous Dispersion of SiO2 Single-layer Coating
LI Xiang-bo, GAO Jin-song, WANG Tong-tong, WANG Xiao-yi, CHEN Hong, ZHENG Xuan-ming, SHEN Zhen-feng, ZHU Hua-xin, YIN Shao-hui, LIU Xiao-han, and WANG Shan-shan
Utilizing the concept of equivalent refractive index,the dispersive model of single SiO2 layer was presented based on the discussion of refractive index variation with the incident flux angle.The dispersion and transmittance curves of the SiO2 films were obtained.The experiment shows that it is periodic variation of reUtilizing the concept of equivalent refractive index,the dispersive model of single SiO2 layer was presented based on the discussion of refractive index variation with the incident flux angle.The dispersion and transmittance curves of the SiO2 films were obtained.The experiment shows that it is periodic variation of refractive index along film thickness that made its equivalent refractive index related to wavelength different to the one of dense film.The larger the index variation range and its period along film thickness,the more anomalous dispersion the films performed..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2006 (2009)
Subwavelength Imaging Properties of Multilayered Metallodielectric Nanofilms
ZHENG Gai-ge, JIANG Li-yong, QIANG Hai-xia, and LI Xiang-yin
The characteristics of a metamaterial consisting of multilayered Ag/Si3N4 nanofilms are studied and the eigen mode expansion (EME) method is used to demonstrate the subwavelength imaging effect. A point source placed in the vicinity of the structure can form a image in the opposite side of the slab, the impedance matchThe characteristics of a metamaterial consisting of multilayered Ag/Si3N4 nanofilms are studied and the eigen mode expansion (EME) method is used to demonstrate the subwavelength imaging effect. A point source placed in the vicinity of the structure can form a image in the opposite side of the slab, the impedance match is not necessary since the Fabry-Perot condition is fulfiled (the thickness of the structure is an integer number of half-wavelengths) and the reflections from the interfaces are almost eliminated. The subwavelength imaging effect in this structure based on the self-collimation but not the negative refraction. This structure verifies that the use of one-dimensional metallodielectric (1D-MD) structure is a very prospective way of extending the use of near-field enhancement phenomenon into the optical region..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2011 (2009)
Optimized Algorithm of Polarization Controlling for Thin-film Filters at Oblique Incidence
NIE Ming-ju, and LIU De-ming
Beginning with the analysis of phase relationship and by use of the characteristic matrix expression of multilayer films, three implicit function expressions of the refractive index and thickness of spacer and central wavelength or half pass-band of two polarization components are deduced. Therefore the values of middlBeginning with the analysis of phase relationship and by use of the characteristic matrix expression of multilayer films, three implicit function expressions of the refractive index and thickness of spacer and central wavelength or half pass-band of two polarization components are deduced. Therefore the values of middle layers refractive index and thickness and corresponding wavelength difference can be quickly and accurately obtained. Simulation calculations of concrete filter designs for four cavities prove that the method is feasible. It is obtained that short or long pass-band depolarization cutoff filter and central wavelength depolarization filter by adjusting effective refractive index and thickness of spacer. The optimized algorithm is effective for polarization controlling of thin film filter at oblique incidence..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2015 (2009)
Effect of Annealing Temperature on the TiO2 Nanosized Thin Films Sensing Troperties Towards Ethanol Vapor*
LI Yang
Nanosized TiO2 thin films were prepared by the method of DC magnetron sputtering,and the films were deposited on alumina tubes and silicon substrates. After the deposition, the films were annealed at 500℃, 700℃ and 1 100℃ in a muffle respectively. The film properties such as crystal structure, grain size, phase and gasNanosized TiO2 thin films were prepared by the method of DC magnetron sputtering,and the films were deposited on alumina tubes and silicon substrates. After the deposition, the films were annealed at 500℃, 700℃ and 1 100℃ in a muffle respectively. The film properties such as crystal structure, grain size, phase and gas sensitivity varied on account of the annealing condition. X-ray diffraction (XRD) and gas sensing measurements were carried out to find out the relation between sensitivity and annealing temperature. Anatase occurs at annealing temperature 500℃. Sensitivity is the highest with wonderful selectivity and shortest response(recover) time for the anatase phase. After modified the surface of TiO2 thin film,it could be concluded that the best operating temperature for the devices is 370℃. The mechanism of the gas sensing properties was also discussed..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2019 (2009)
Polarization Induced Fading Eliminating Technique for Interferometric Optical Fiber Sensor
JING Zhen-guo, YIN Kai, ZHANG Min, WANG Li-wei, ZHU Yao-qiang, WANG Zhi-qiu, WANG Hong-hua, and LIAO Yan-biao
A method of polarization induced fading eliminating with PDR (Polarization Diversity Receiver) is analyzed theoretically. Complete polarization induced fading is avoided through tri-state PDR method. The phase measurement result of PGC(Phase Generated Carrier) demodulating technology based on ARCTAN calculation is immuA method of polarization induced fading eliminating with PDR (Polarization Diversity Receiver) is analyzed theoretically. Complete polarization induced fading is avoided through tri-state PDR method. The phase measurement result of PGC(Phase Generated Carrier) demodulating technology based on ARCTAN calculation is immune to amplitude change of interference signal due to polarization induced fading. Combination of tri-state PDR method and PGC demodulating technology based on ARCTAN calculation overcomes the problem of polarization induced fading in interferometric optical fiber sensor and ideal demodulation of phase signal will be implemented..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2024 (2009)
The Sensing Law of Optical Fiber Corrosion Sensor with Fe-C Alloy Film
LI Wei, and YAN Lei-peng
By the two methods that PVD sputtering and PVD sputtering associated with electroplating，the different thickness Fe-C alloy films on fiber core were made. X-ray diffraction results show that the Fe-C alloy films have the same crystal structure as ordinary steel. In order to carry on the corrosion experiments, putting tBy the two methods that PVD sputtering and PVD sputtering associated with electroplating，the different thickness Fe-C alloy films on fiber core were made. X-ray diffraction results show that the Fe-C alloy films have the same crystal structure as ordinary steel. In order to carry on the corrosion experiments, putting the galvanized fiber into different concentration HNO3 solutions and concrete block respectively. The results show that: In low concentration etching solution, the different thickness Fe-C alloy films can be eroded from outside to inside evenly:,and the output optical power increases suddenly in the corrosion last stage;In highly concentrated etching solution, the Fe-C alloy films produce the crack in many parts, the films are perished piece by piece, and the output optical power increases gradually in the mass;In the corrosion experiment which was made in a concrete block, the change of the output optical power is complicated, but in the whole it is increased..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2029 (2009)
Retrieving Method of Differential Optical Absorption Spectroscopy Based on M-estimator Robust Regression*
MA Jin-ji, and LI Su-wen
With differential optical absorption spectroscopy (DOAS), trace gases in the atmosphere can be measured and its concentrations can be retrieved based on least squares regression. Under complicated atmospheric conditions, there are outliers and the error distribution is not normal in DOAS differential spectra, which resWith differential optical absorption spectroscopy (DOAS), trace gases in the atmosphere can be measured and its concentrations can be retrieved based on least squares regression. Under complicated atmospheric conditions, there are outliers and the error distribution is not normal in DOAS differential spectra, which resulted in misestimate of least-squares regression. The retrieving model of robust regression based on M-estimator was developed to evaluate concentrations of trace gases in DOAS system. The evaluation procedure and effects using M-estimator robust regression were studied. The normal spectrum and abnormal spectrum were retrieved basing on two methods. Experimental results show that reliability is improved with method of robust regression in DOAS evaluation..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2035 (2009)
Monitoring and Analysis of Atmospheric Pollutants in Traffic Ban Period of Beijing with DOAS
ZHU Yan-wu, LIU Wen-qing, XIE Pin-hua, DOU-ke, SI Fu-qi, LI Su-wen, ZHANG Yin-hua, and QIN Min
Based on the differential optical absorption spectroscopy (DOAS) technology, measurements of atmospheric pollutants were carried out continuously in August. 2007 at Chaoyang District,Beijing. Diurnal variation characteristics of pollutants and sources are analyzed. And relations between pollutants and meteorological coBased on the differential optical absorption spectroscopy (DOAS) technology, measurements of atmospheric pollutants were carried out continuously in August. 2007 at Chaoyang District,Beijing. Diurnal variation characteristics of pollutants and sources are analyzed. And relations between pollutants and meteorological conditions are discussed. Moreover, the concentrations of NO2, SO2 and O3 in the period of “Good Luck Beijing” Olympic test games (traffic ban August 17-20 and no traffic ban August 16, 21) are given emphasis to analyze. Results indicate that automobile exhaust is the main source of NO2, and the concentration of NO2 is high in the a.m. and wee hours. It can also be found that NO2 contributes part to the O3 formation. SO2 came mainly comes from the southwest and the concentration of SO2 decreased with the north wind. Traffic ban reduces the levels of NO2,SO2 of 28.34％ and 25.87％, respectively,but the levels of O3 increase..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2040 (2009)
A Simple Method of Deducing the Optical Constants of Thin Films Using the Optical Transmission Spectrum
ZHAO Qiang, WANG Ji-qing, and CHAI Zhi-fang
According to the single oscillator expression, based on a based on classic electromagnetic dispersion model,a simple and efficient computer program aided method for deducing the optical refractive index and thickness of a thin film from the normal-incident transmission spectrum was proposed.A dc sputtered ZnO film was According to the single oscillator expression, based on a based on classic electromagnetic dispersion model,a simple and efficient computer program aided method for deducing the optical refractive index and thickness of a thin film from the normal-incident transmission spectrum was proposed.A dc sputtered ZnO film was analyzed using the method,The results demonstrated that the method is practicable..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2046 (2009)
Design of Optoelectronic Platform for stable image on Airborne Reconnaissance
QIAN Yi-xian, LIANG Wei, and GAO Xiao-dong
Modulation transfer function (MTF) resulting from random vibration was analyzed.The effect angular displacement was regarded as major factor to affect the image of aerial camera.Allowable MTF degradation was represented,and allowable MTF degradation was converted into stable system design parameters.The parameters can Modulation transfer function (MTF) resulting from random vibration was analyzed.The effect angular displacement was regarded as major factor to affect the image of aerial camera.Allowable MTF degradation was represented,and allowable MTF degradation was converted into stable system design parameters.The parameters can guide perfect design for stabilization system.Based on the spatial mechanism and translational principle of parallelogram,an irrotational displacement isolator was developed,which can meet the requirements of irrotational displacement and damp.An instance was given,and 34 dB reduction was achieved at frequency of 100HZ.With the help of MSC.ADAMS simulation software,curve proves correct for isolator was simulated,and the irrotational displacement mechanism was tested by optical method with coupled angle being less than 8″,which can satisfy the demand of aerial imaging..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2108 (2009)
Real-time Acquisition and Storage System for Explosion Flash Pulse Waveform
SHU Ya, OU-YANG Xian, BAI Yong-lin, and LIU Bai-yu
An explosion waveform acquisition and storage system which is designed for explosion time measurement is introduced.FPGA is used to control A/D converter and flash memory,the data is acquired and stored in the speed of 1data/1μs.Then the data is transferred by PC/104 bus into PC/104 computer to do further processing toAn explosion waveform acquisition and storage system which is designed for explosion time measurement is introduced.FPGA is used to control A/D converter and flash memory,the data is acquired and stored in the speed of 1data/1μs.Then the data is transferred by PC/104 bus into PC/104 computer to do further processing to get a complete explosion waveform and the explosion time..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2112 (2009)
Arbitrary Motion Blurred Image Restoration
MAO Cheng-jun, LI Qi, XU Zhi-hai, FENG Hua-jun, and CHEN Yue-ting
An approach which can be used to restore the images that were blurred by arbitrary motion was propose in this paper. When exposure time, video frequency were caught by the ccd that has high frame frequency, which were used to compute the information about the motion and finally compute the point spread function(PSF), nAn approach which can be used to restore the images that were blurred by arbitrary motion was propose in this paper. When exposure time, video frequency were caught by the ccd that has high frame frequency, which were used to compute the information about the motion and finally compute the point spread function(PSF), necessary to restore the motion-blurred image..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2126 (2009)
Improvement of Bi-polynomial Method for Beam Hardening Correction Based on Consistency of CT Data
ZHANG Yan-bo, TANG Shao-jie, and MOU Xuan-qin
Due to all kinds of correction algorithms have little effects on streak artifact at present,the reason of streak artifact is analyzed.Therefore,considering that the influence of soft tissue caused by the X-rays which penetrate through different bone thicknesses are different,the soft tissue correction polynomial in Bi-Due to all kinds of correction algorithms have little effects on streak artifact at present,the reason of streak artifact is analyzed.Therefore,considering that the influence of soft tissue caused by the X-rays which penetrate through different bone thicknesses are different,the soft tissue correction polynomial in Bi-Polynomial correction method is improved based on H-L consistency condition.Forbild head phantom simulation results show that the improved algorithm can get better correction effect on both cupping artifact and streak artifact..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2131 (2009)
A New Correction Method of IRFPA Nonuniformity Based on Stationary Wavelet Transform
ZHANG Feng, LIU Shang-qian, and WANG Da-bao
Based on the analysis of fixed pattern noise on the basis of frequency distribution, a correction method using stationary wavelet was proposed. The infrared image sequence was decomposed by a proper wavelet function, thereby the gain and offset coefficients were estimated and eventually the infrared focal plane array nBased on the analysis of fixed pattern noise on the basis of frequency distribution, a correction method using stationary wavelet was proposed. The infrared image sequence was decomposed by a proper wavelet function, thereby the gain and offset coefficients were estimated and eventually the infrared focal plane array nonuniformity correction was realized. The resolution of low-frequency part was improved by the virtue of the wavelet with its multi-resolution properties, so the “artificial ghost” phenomenon which appears in some scene-based NUC algorithm was restrained. Experiments on real infrared image sequence prove the superiority of the algorithm, and have achieved satisfactory results..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2135 (2009)
Image Automatic Mosaic Method Based on Feature Points and Optimization Theory
HUANG Qiong-dan, QIU Yue-hong, and TIAN Xiao-ping
A new method for image mosaic is presented.Phase congruency algorithm is utilized to extract feature points. The proposed auto matching point optimizing method is used to realize the automatic selection of matching points. Levenberg-Marquardt optimization algorithm is used to estimate the transformation matrix between A new method for image mosaic is presented.Phase congruency algorithm is utilized to extract feature points. The proposed auto matching point optimizing method is used to realize the automatic selection of matching points. Levenberg-Marquardt optimization algorithm is used to estimate the transformation matrix between two images accurately. Ａnd, the seamless image mosaic is completed with smoothing algorithm. This method combines both feature points-based and optimization theory-based approach effectively, and it can make full use of image overlap information. This method can overcome the effect of noise and non-uniform illumination. Therefore it is more precise and robust than conventional algorithm. The experimental results illustrate that this method is very satisfied..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2139 (2009)
Adaptive Threshold Detection Method for Dim and Small Target Based on Image Complex Degree
LI Xin, ZHAO Yi-Gong, and GUO Wei
In order to detect dim and small infrared targets,a new approach based on image complex degree is proposed.Four image information entropies of different regions are discussed.Image information entropy describes the average information contents efficiently,but insensitive to point mutations.So information entropy weightIn order to detect dim and small infrared targets,a new approach based on image complex degree is proposed.Four image information entropies of different regions are discussed.Image information entropy describes the average information contents efficiently,but insensitive to point mutations.So information entropy weighted by image variance is introduced to describe image complexity.Two specific analysis models are utilized to obtain image complexity features.It is found that there is much difference in target regions,while almost no difference in non-target regions.After the establishment of the self-adaptive exponent models for the difference image of two complexity features,the dim and small targets can finally be detected with self-adaptive threshold processing.Experimental results show that the proposed method can detect dim and small targets in clouds cluster image with low SCR very efficiently..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2144 (2009)
Image Retrieval Based on Bit-plane Distribution Feature
ZHAO Shan, and ZHAI Hai-xia
The content-based image retrieval on histogram was analyzed and a novel image retrieval algorithm was proposed based on bit-plane distribution feature. Firstly, the feature of the noise was considered and the image is divided into eight bit-planes by the image bit-plane-code. Then, the Bit-plane Distribution Feature (BThe content-based image retrieval on histogram was analyzed and a novel image retrieval algorithm was proposed based on bit-plane distribution feature. Firstly, the feature of the noise was considered and the image is divided into eight bit-planes by the image bit-plane-code. Then, the Bit-plane Distribution Feature (BPDF) was constructed according to statistic distribution of the four significant planes which contain most of the structural information of the image. Meantime, the gray-code of bit-planes was used to avoid the effect of changes in the image intensity values on bit-planes. Finally the Mahalanobis distance was adopted to measure the similarity because of the correlation between the concerned vectors after designing the correlation-weighted matrix. Experimental results show that the proposed method has sound retrieval performance..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2150 (2009)
High Resolution Image Reconstruction Based on Uncontrolled Microscanning
CHEN Yan, JIN Wei-qi, XU Chao, WANG Xia, GAO Mei-jing, and WANG Ling-xue
Aiming at a series of Low Resolution( LR ) images with uncontrolled micro-displacements, an algorithm based on 2×2 uncontrolled microscanning is represented to reconstruct the High Resolution(HR) image. It uses the algorithm of Linear Interpolation Projection based on Shift Estimation(LIPSE) to estimate the micro-Aiming at a series of Low Resolution( LR ) images with uncontrolled micro-displacements, an algorithm based on 2×2 uncontrolled microscanning is represented to reconstruct the High Resolution(HR) image. It uses the algorithm of Linear Interpolation Projection based on Shift Estimation(LIPSE) to estimate the micro-displacements of the LR images, and then reconstructs the HR image from the four LR images by using the reconstruction algorithm based on Taylor series expansion. Simulation and practical image processing demonstrate that this algorithm can estimate displacements accurately of serial images and get good reconstruction effect, and the algorithm is simple but effective with small processing load, so it is very possible to achieve fast processing. The method is hopeful to meet the demand of HR imaging in the fields of synchronous satellite and public surveillance..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2155 (2009)
Multipurpose Watermarking Algorithm Based on Krawtchouk Moment and Contourlet Transform
WU Yi-quan, XIE Jing, and PANG Lei
A multipurpose watermarking scheme for digital image is proposed.After contourlet transform,the subband coefficients are extracted.Then the lower order Krawtchouk moments of the low frequency subbands coefficients are computed,and the watermark is composed of the mean of several functions of the moments.An embedded domA multipurpose watermarking scheme for digital image is proposed.After contourlet transform,the subband coefficients are extracted.Then the lower order Krawtchouk moments of the low frequency subbands coefficients are computed,and the watermark is composed of the mean of several functions of the moments.An embedded domain from other subbands is chosen,and the semi-fragile watermark is embedded in it.Quantitative evaluation of invisibleness,ability of resisting the attack and location ability of resisting the falsification of the watermark was made.The results demonstrate the effectiveness of our algorithm in terms of robustness and semi-fragility..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2160 (2009)
Atmospheric and Oceanic Optics
Aero-Optic Effects Induced by the Fluctuation Flowfield Surrounding Hypersonic Aircrafts
YANG Wen-xia, CAI Chao, DING Ming-yue, and ZHOU Cheng-ping
Computational analysis was carried out regarding the aero-optical effect induced by the turbulence field surrounding the hyper-speed aircraft.The transport equation of the variance of the index of refraction fluctuations was derived based on the scalar transport governing equations of the turbulence model. The refractiComputational analysis was carried out regarding the aero-optical effect induced by the turbulence field surrounding the hyper-speed aircraft.The transport equation of the variance of the index of refraction fluctuations was derived based on the scalar transport governing equations of the turbulence model. The refraction fluctuation variances and the fluctuations correlation and phase covariance function along the line-of sight were obtained. Using statistical methods, the turbulent modulation transfer function(MTF) and the refraction correlation function induced in the transmission direction for the refraction fluctuation was computed, which characterized the aero-optical effect in different aspects. Experimental results show that the amplitude response of the transmission function of the aero-optical effect can be characterized as a low-pass filter, which results blurring in the obtained image; while its irregular phase response results nonlinear shifts of the target in the image.And, the higher the Mach number, the more severe the distortion in the image. The correctness of the theoretical MTF was evaluated by wind tunnel experiment..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2117 (2009)
Intensity Distribution of Focused Hollow Vortex Beams with a Gaussian Background in Turbulent Atmosphere
CANG Ji, ZHANG Yi-xin, and XU JIAN-cai
Based on the extended Huygens-Fresnel principle and the quadratic approximation of phase structure function, the theoretical modal of optical intensity distribution on the focal plane for focused hollow vortex beams with a Gaussian background propagating in turbulent atmosphere was investigated and obtained.The effectsBased on the extended Huygens-Fresnel principle and the quadratic approximation of phase structure function, the theoretical modal of optical intensity distribution on the focal plane for focused hollow vortex beams with a Gaussian background propagating in turbulent atmosphere was investigated and obtained.The effects of atmospheric index structure constant C2n, topological charge, focal length and beam wavelength on optical intensity distribution on the focal plane were analyzed. The results indicate that with the increase of focal length, the intensity distribution on the focal plane varies from central-dip form to Gaussian distribution. The effects of weak turbulence on intensity distribution are negligible. The maintenance of singularity of vortex beams with larger topological charge in turbulent atmosphere is better than that for vortex beams with smaller topological charge. The central-dip form of the intensity distribution becomes shallow and the intensity distribution becomes smooth with the turbulence outer scale increasing..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2122 (2009)
Fiber Optics and Optical Communications
Fibonacci Quasi-periodic Superstructure Fiber Bragg Gratings
ZHANG Jian, ZHENG Jie, and ZHANG Yu-shu
Quasi-periodic superstructure fiber Bragg gratings (SFBG) of 0~9 Fibonacci order with the central wavelength 1 541.86 nm were written into single mode photo-sensitive fiber by phase-mask scanning technique. The fabrication parameters were optimized by simulating the UV induced refractive index change in the fiber core.Quasi-periodic superstructure fiber Bragg gratings (SFBG) of 0~9 Fibonacci order with the central wavelength 1 541.86 nm were written into single mode photo-sensitive fiber by phase-mask scanning technique. The fabrication parameters were optimized by simulating the UV induced refractive index change in the fiber core. Both theoretical and experimental results show that the transmission spectra were multi-fractal, self-similar and the transmission coefficients have six-cycle property. The fabricated SFBG can be served as C-band multi-frequency optical device in optical integrated circuits and optical communication system..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2050 (2009)
Noncontact Optical Fiber Measuring Technology for Transient Signal Based on Sagnac Interferometer
TAO Pei-lin, WANG Yan-hua, REN Wen-hua, TAN Zhong-wei, YAN Feng-ping, and JIAN Shui-sheng
Based on theoretical analysis of Sagnace interferometer, a noncontact optical fiber measuring technology is proposed. The related demodulation technique is developed in accordance with the characteristics of trap wave. The results show that, the noncontact optical fiber measuring technology based on Sagnac interferometBased on theoretical analysis of Sagnace interferometer, a noncontact optical fiber measuring technology is proposed. The related demodulation technique is developed in accordance with the characteristics of trap wave. The results show that, the noncontact optical fiber measuring technology based on Sagnac interferometer can realize the identification of transient signal,and realize the location of sound signal source according with the relative location precise of 1.5%..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2055 (2009)
Growth and Characteristics of Pr3+ and Ce3+ ions doped YAG Crystal Fiber for White LED
YE Lin-hua, ZHOU Xiao-fen, SONG LI, Li Gang, and LIU Xiang-fang
Pr3+,Ce3+:YAG crystal fibers were grown by laser heated pedestal growth method as the white LED materials.The Luminescence properties of the materials was investigated,and the results show that in Ce3+ ions and Pr3+ ions codoped fluorescence emission process the Pr3+ ions 610 nm fluorescence intensity can be increased Pr3+,Ce3+:YAG crystal fibers were grown by laser heated pedestal growth method as the white LED materials.The Luminescence properties of the materials was investigated,and the results show that in Ce3+ ions and Pr3+ ions codoped fluorescence emission process the Pr3+ ions 610 nm fluorescence intensity can be increased by Ce3+ ions sensitization. High efficient white LED was gotten by combined Blue LED and grown Pr3+,Ce3+:YAG crystal fiber. The white LED was improved with the CIE color coordinates (x＝0.322, y＝0.335) and 84.3 of the CRI. It can be used for high effient power white LED in future..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2059 (2009)
Linearly Chirped Long Period Gratings Used for EDFA Gain Flattening
XU Xin-hua, and WANG Qing
The linearly chirped long period grating with special refractive index for EDFA gain flattening is presented. Runge-Kutta algorithm is used to numerically solve the coupled-mode equations of this type of grating. The grating structure parameters including grating length, period, linear chirp coefficient and the core reThe linearly chirped long period grating with special refractive index for EDFA gain flattening is presented. Runge-Kutta algorithm is used to numerically solve the coupled-mode equations of this type of grating. The grating structure parameters including grating length, period, linear chirp coefficient and the core refractive index profile are optimized by Nelder-Mead arithmetic. A linearly chirped long period grating with appropriate parameters is designed to flatten the gain spectrum of EDFA. The flattened gain spectrum has a bandwidth of 35 nm in C wave band and a fluctuation in ±0.5 dB..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2063 (2009)
Performance Analysis of Two-stage Double-clad Er3+/Yb3+ Co-doped Fiber Amplifier
WU Yue-xiang, MA Xiao-ming, and ZHAO Xiao-ji
The performances of two-stage double-clad Er3+/Yb3+ co-doped fiber amplifier（EYDFA）are analyzed based on the rate equation and light propagation equation.The optimum length and the influence of the ratio of forward and backward pump power on gain and noise characteristics of two-stage double-clad EYDFA are obtained witThe performances of two-stage double-clad Er3+/Yb3+ co-doped fiber amplifier（EYDFA）are analyzed based on the rate equation and light propagation equation.The optimum length and the influence of the ratio of forward and backward pump power on gain and noise characteristics of two-stage double-clad EYDFA are obtained with numerical simulation.The gain improvement of 4 dB and the noise figure reduction of 3 dB is obtained by choosing the optimum position of the isolator and the the ratio of forward and backward pump power..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2066 (2009)
An Efficient Secure Lightpath Establishment Protocol in ASON
ZHOU Xian-wei, WU Qi-wu, WANG Jian-ping, WANG Li-na, and SUN Yong
To the point of security threats against lightpath establishment process in ASON, an efficient secure lightpath establishment protocol is presented. This protocol uses integrated strategy of wavelength reservation, and makes use of digital signature and message feedback security mechanisms to protect the integrity of iTo the point of security threats against lightpath establishment process in ASON, an efficient secure lightpath establishment protocol is presented. This protocol uses integrated strategy of wavelength reservation, and makes use of digital signature and message feedback security mechanisms to protect the integrity of important object in GMPLS RSVP-TE message and prevent malicious or selfish actions from inner node. In addition, in view of the close coupling character of routing and signaling module in ASON, this protocol adopts PKLSA message of OSPF-TE to distribute nodes public key certificate which the lightpath establishment protocol demanded. Through simulation experiment and analysis, it is proved that this protocol can ensure the security of lightpath establishment,and has better performance than the old RSVP-TE protocol in terms of connection block probability, lightpath connection setup time and message overhead..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2071 (2009)
Physical Optics
Multiple Scattering of Laser Beam Propagating in Ship Wakes
SUN Chun-sheng, ZHANG Xiao-hui, and ZHU Dong-hua
Intensity distributing characters on the axis of Gaussian beam propagating in ship wakes and on the cross-section vertical to the beam axis are investigated to understand the transferring property of laser beam in wakes and to provide the theoretic basis for detecting ship wakes by forward light beam attenuation.Based Intensity distributing characters on the axis of Gaussian beam propagating in ship wakes and on the cross-section vertical to the beam axis are investigated to understand the transferring property of laser beam in wakes and to provide the theoretic basis for detecting ship wakes by forward light beam attenuation.Based on the solution of the radiation transfer equation in the narrow angle approximation,the formulations for radiation intensity,which is divided into un-scattered intensity and scattered intensity denoting the extent of multiple scattering,detected by received section are derived.Given a typical bubbles′ distributing function,numerical computations and analysis are given for the un-scattered intensity and scattered intensity on the beam axis relating to detector′s view of field,optical depth,and beam size; similarly the numerical results are also presented for the radiation intensity on the cross-section vertical to the beam axis relating to transverse distance and beam size.The results show that the multiple scattering coming from laser beam propagating in ship wakes is obvious,and the extent of multiple scattering has a close connection with view of field,beam size,optical depth,and transverse distance..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2077 (2009)
Properties of Laser-Induced Cavitation Bubble Sound Waves in Viscous Fluid
LI Sheng-yong, ZHU Qiang-hua, ZHAO Rui, SHEN Zhong-hua, and NI Xiao-wu
The properties of laser-induced cavitation bubble collapse sound waves during the high-power laser and matter interaction in different viscous liquids were investigated by the piezoelectric transducer(PZT) hydrophone.The experimental results indicate that the liquid viscosity has an obvious influence on laser-induced cThe properties of laser-induced cavitation bubble collapse sound waves during the high-power laser and matter interaction in different viscous liquids were investigated by the piezoelectric transducer(PZT) hydrophone.The experimental results indicate that the liquid viscosity has an obvious influence on laser-induced cavitation bubble collapse sound waves,larger viscosity makes the intensity of sound waves more feeble,and the peak of frequency becomes higher and higher..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2082 (2009)
Change of Polarization of Vortex Beams Induced by Diffraction Effect
LIN Hui-chuan, and PU Ji-xiong
Based on the Huygens-Fresnel Principle and the unified theory of coherence and polarization of partailly coherent beams, the degree of polarization of partially coherent vortex beams transmitted through the circular aperture has been investigated. It is found that the degree of polarization will change after the beam tBased on the Huygens-Fresnel Principle and the unified theory of coherence and polarization of partailly coherent beams, the degree of polarization of partially coherent vortex beams transmitted through the circular aperture has been investigated. It is found that the degree of polarization will change after the beam transmitted through the circular aperture, and the degree of polarization of the diffractive beam is related with the coherence of source, the topological charges of the source, and the size of the circular aperture..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2087 (2009)
The Spectral Degree of Cross -polarization of Stochastic Electromagnetic Beams
ZHANG Guo-wen, PU Ji-xiong, SAHIN Sahin, and OLGA Korotkova
Based on the theory of spectral degree of cross-polarization, the behaviour of spectral degree of cross-polarization of a electromagnetic Gaussian Schell-model beam on propagation is studied. The expressions for the elements of the cross-spectral density matrix the beam propagating in free space for arbitrary two pointBased on the theory of spectral degree of cross-polarization, the behaviour of spectral degree of cross-polarization of a electromagnetic Gaussian Schell-model beam on propagation is studied. The expressions for the elements of the cross-spectral density matrix the beam propagating in free space for arbitrary two points in the beam has been derived by using the unified theory of coherence and polarization and the extended Heygens-Fresnel integral. The results show that, the degree of cross-polarization of partially coherent electromagnetic beams in free space may take on any nonnegative values, in contrast to the usual degree of polarization which is restricted to the range 0~1.The behavior of the degree of cross-polarization on propagation is determined by all the parameters of the source radiating the beam. At sufficiently large distances from the source the degree of cross-polarization stabilizes for all points within the beam independently of their radial positions.The condition for keeping the degree of cross-polarization invariant is the same as that of the usual degree of polarization..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2093 (2009)
Liquid Drop Surface on Horizontal Plane by Means of Optical Method
QI Jian-xia, and MIAO Run-cai
The optical effect of the steady droplet on the horizontal plane was studied.When a collimated-beam illuminated upon the symmetric droplet surface form below in a vertical direction,the steady and visible diffraction pattern was observed experimentally,and the relationship between the intensity distribution of the pattThe optical effect of the steady droplet on the horizontal plane was studied.When a collimated-beam illuminated upon the symmetric droplet surface form below in a vertical direction,the steady and visible diffraction pattern was observed experimentally,and the relationship between the intensity distribution of the pattern and the illuminated area covered by the beam was found.While the diameter of the beam changes from larger to small,the intensity distribution of the pattern changes,either.The disappearance of the zero-order diffraction fringe,which corresponds to the 100% efficiency,was also observed in the experiment.Based on the physical optical theory,the analytic expression of the intensity distribution of pattern was derived,which explained the disappearance of the zero-order fringe well,and the height of the droplet at the certain position was also obtain.A novel method for the axisymmetric liquid surface deposited on the horizontal plane was found..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2099 (2009)
Laser Resonator Software Arithmetic and Realization by Computer
YU Dian-bao, XUE Jun-wen, and GAO Kai
In order to make analysis and design of the parameters of laser resonators easily,laser resonator software arithmetic is studied and realized using computer.ABCD matrix mechanism is used to analyze and design laser resonators.To obtain the generic and universal method,which is used to program,the matrix of all elementsIn order to make analysis and design of the parameters of laser resonators easily,laser resonator software arithmetic is studied and realized using computer.ABCD matrix mechanism is used to analyze and design laser resonators.To obtain the generic and universal method,which is used to program,the matrix of all elements is considered as complex matrix.And,beam quality factor M2 and the index of the media are also considered.When the imaginary parts of the complex matrix are zero,and the beam quality factor M2 and media index equal to one,the stated method will be transformed to the usual conditions which are fundamental mode transmitting through real elements in the air.Based on the method of multi-mode transmitting through complex elements in the media,laser resonator software,which can analyze and design stable standing cavity,stable travelling cavity,unstable standing cavity,unstable travelling cavity,phase conjugate cavity and beam transmission,is realized by VB programmed language..
Acta Photonica Sinica
- Publication Date: Aug. 25, 2021
- Vol. 38, Issue 8, 2104 (2009)
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