Journals >Acta Photonica Sinica
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2011
Volume: 40 Issue 9
33 Article(s)
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Research Article
[in Chinese]
[in Chinese]
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1 (2011)
Characteristics of Ytterbium-doped Double-cladding Pulsed Fiber Amplifiers
ZHANG Xiao, SONG Yan-rong, YU Zhen-hua, YANG Zhao-hui, TIAN Jin-rong, and ZHANG Xin-ping
Output characteristics of Yb-doped double-cladding pulsed fiber amplifiers were discussed under conditions of low and high repetition rates using the time-dependent rate equations. Because there are several different initial conditions used in the finite-difference method with different repetition rates, some methods wOutput characteristics of Yb-doped double-cladding pulsed fiber amplifiers were discussed under conditions of low and high repetition rates using the time-dependent rate equations. Because there are several different initial conditions used in the finite-difference method with different repetition rates, some methods were presented to determine the initial conditions. The relationship of the peak powers of the high repetition rates with their equivalent continuous wave powers was also discussed when the signal light was in Gaussian shape. The change of the average output power with the pump power was obtained under the conditions of the pulsed signals with low repetition rates and high repetition rates..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1287 (2011)
Optical Pulses Compression Based on Fiber-optical Parametric Amplifier
ZHANG Xiao-yuan, YU Jin-long, LUO Jun, WANG Wen-rui, WU Bo, GUO Jing-zhong, and YANG En-ze
For optical short pulse with high frequency, it is needed to improve the pump power to obtain more shorter pulse; but, as increasing of the pump power, the gain of the amplifier is becoming saturated, and amplified spontaneous emission noise (ASE) is increasing, so signal to noise ratio (SNR) is decreased. A scheme of For optical short pulse with high frequency, it is needed to improve the pump power to obtain more shorter pulse; but, as increasing of the pump power, the gain of the amplifier is becoming saturated, and amplified spontaneous emission noise (ASE) is increasing, so signal to noise ratio (SNR) is decreased. A scheme of pulse compression through fiber-optical parametric amplifier and chirp management is proposed. First the pump light is phase modulated after intensity modulation to introduce linear positive chirps, after the parametric progress the frequency chirps of the idler are doubled, so its spectral width is increased, the pulse can be compressed through dispersion compensation medium. The experimental results of 10GHz operation is demonstrated, with 0.5W average pump power and phase modulated pump power, idler pulse is observed with 19ps pulse width..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1292 (2011)
Distributed Optical Fiber Raman Temperature Measurement System Based on the Dynamic Multi-section Temperature Calibration
JIN Zhong-xie, CUI Hai-jun, NING Feng, LI Xiao-qin, and ZHU Yong
A new temperature calibration equipment is designed based on the thermoelectric cooler module, and a novel temperature calibration method using dynamic multi-section optical fiber is applied and its feasibilty and accuracy are verified by experiments. With the changing of external temperature, the temperature at any poA new temperature calibration equipment is designed based on the thermoelectric cooler module, and a novel temperature calibration method using dynamic multi-section optical fiber is applied and its feasibilty and accuracy are verified by experiments. With the changing of external temperature, the temperature at any point along the optical fiber can be sensed and demodulated accurately. This temperature demodulation method is accurater, more stable and suitable for the applications under the complex practical environment. The error of the multistage temperature calibration is less than 1 ℃..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1297 (2011)
Embedded Waveguide Thermo-optic Switch Based on Novel Organic-inorganic Hybrid Material
WANG Hui, ZHANG Feng, LIU Tian-ji, WANG Fei, SUN Xiao-qiang, CHEN Chang-ming, and ZHANG Da-ming
A kind of novel organic-inorganic hybrid core layer material with good optical properties and high thermal stabilities was synthesized via sol-gel process. Epoxy-crosslinking can be realized in the hybrid material owing to the existence of organic flexible lateral chains in the molecules. Compared with the inorganic SiA kind of novel organic-inorganic hybrid core layer material with good optical properties and high thermal stabilities was synthesized via sol-gel process. Epoxy-crosslinking can be realized in the hybrid material owing to the existence of organic flexible lateral chains in the molecules. Compared with the inorganic SiO2-TiO2 system, this kind of material exhibited high thermal-optic coefficient(10-4/K) and excellent film characteristics. A kind of thermal curable resist P(MMA-GMA) was synthesized as the cladding material. The embedded waveguide thermo-optic switch of Mach-Zehnder type was designed and fabricated well. The insertion loss of the device is 10 dB, the driving power is 15 mW, the switching time is less than 1 ms and the extinction ratio is 15 dB..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1303 (2011)
Novel Ge-Te-I Far-Infrared-Transmitting Chalcogenide Glasses System
HE Yu-ju, NIE Qiu-hua, SUN Jie, WANG Xun-si, WANG Guo-xiang, DAI Shi-xun, SHEN Xiang, and XU Tie-feng
A novel Ge-Te-I far infrared transmitting chalcohalide glass system Ge20Te80-xIx(x=2, 4, 6, 8mol%) was prepared by traditional melt-quenching method. Structure and physicochemical properties of Te-based glass system were studied with XRD, SEM and DTA. The effect of halogen on the glass formation and thermal stability wA novel Ge-Te-I far infrared transmitting chalcohalide glass system Ge20Te80-xIx(x=2, 4, 6, 8mol%) was prepared by traditional melt-quenching method. Structure and physicochemical properties of Te-based glass system were studied with XRD, SEM and DTA. The effect of halogen on the glass formation and thermal stability was investigated. Optical spectra of Te-based glass system were obtained by spectrophotometer and infrared spectrometer. Effect of halogen on the short-wavelength absorption cut-off edge and infrared transmitting spectra was analyzed. The Tauc equation was used to calculate the direct and indirect optical band gap. The results show that halogen can reduce Te metallic character and improve the glass-forming ability. The density decreased while the molar volume increased with the added I2 content. With the addition of I2, the short-wavelength cut-off edge of the glasses shifts to the longer wavelength (1 700~1 900 nm), the band gap decreased. The thermal stability was enhanced by the addition of halogen. A maximum ΔΤ value of 121℃ was obtained for the glass composition Ge20Te72I8. These prepared Ge-Te-I glasses all have wide optical transmission window from 1.8 to 25 μm, which is a novel far infrared transmitting glass materials..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1307 (2011)
Effect of Substituting Ga for Al on Structure and Spectral Properties of Phosphors SrAl2Si2O8∶Eu2+
WANG Fei, TIAN Yi-guang, ZHANG Qiao, and ZHAO Wen-guang
A series of phosphors Sr0.955Al2－xGaxSi2O8∶Eu2+ (x=0～1.0) was prepared via solid-state reaction in weak reductive atmosphere. Lattice positions and the luminescent mechanism of Eu2+ in the host were discussed, and effects of Ga3+-substitution on the host lattice and spectral properties were investigated. The results shA series of phosphors Sr0.955Al2－xGaxSi2O8∶Eu2+ (x=0～1.0) was prepared via solid-state reaction in weak reductive atmosphere. Lattice positions and the luminescent mechanism of Eu2+ in the host were discussed, and effects of Ga3+-substitution on the host lattice and spectral properties were investigated. The results showed that complete solid solutions formed in the whole range of x=0～1.0 while Ga3+ entered SrAl2Si2O8 lattice and substituted Al3+. The lattice parameters (a, b, c) and unit cell volume of phosphors Sr0.955Al2－xGaxSi2O8∶Eu2+ (x=0～1.0) increased linearly as Ga3+ content increased in the phosphors. When Ga3+ substituted for Al3+, the most obvious changes happened in cell parameter c, b was the second and a was the minimum. A broad excitation spectrum of Eu2+ presented from 230 nm to 400nm and peaked at 350 nm, which consists of 267 nm, 305 nm, 350 nm and 375 nm excitation bands. The three shorter wavelengths excitation peaks were shifted to red and the peak intensities of 267 nm and 350 nm were decreased. The peak intensity of 305 nm increased significantly while the peak position and intensity of 375 nm unchanged basically as the increased substitution of Ga3+. The FWHM of the apparent excitation peak narrowed from 109 nm to 98 nm. The broad and asymmetric emission spectrum among 380 nm and 600 nm and apparent peak was at 407 nm, which could be fitted by two peaks at 406 nm and 441 nm. The two fitted peaks were red shifted and the intensity ratio of the fitted peaks increased linearly with the increasing of the amount of Ga3+-substitution. The apparent emission peak was red shift from 407 nm to 422 nm and FWHM increased from 58 nm to 79 nm while Ga3+ content was up to 1.0 mol. The distance of Eu-O was shorted due to Al3+ is replaced by Ga3+. The crystal field of the emitting center Eu2+ location was enhanced. The splitting of 5d orbital levels was increased and the lowest emission level was expanded to lower..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1312 (2011)
Field Experiment and Result Analysis of Fourier Telescopy
DONG Lei, LIU Xin-yue, CHEN Bao-gang, LIN Xu-dong, and WEI Pei-feng
In order to study effects of outdoor factors to Fourier telescopy imaging and validate properties of imaging immune to down-link atmospheric turbulence, outdoor experiments were developed. Under the ground of lab experiments, outdoor experiments added primary mirror, secondary mirror and condense lens to simulate the rIn order to study effects of outdoor factors to Fourier telescopy imaging and validate properties of imaging immune to down-link atmospheric turbulence, outdoor experiments were developed. Under the ground of lab experiments, outdoor experiments added primary mirror, secondary mirror and condense lens to simulate the real system imaging. The distance between object and primary mirror and the distance between primary mirror and secondary mirror was put away 100m, separately, to validate the property of Fourier telescopy imaging immune to atmospheric turbulence. Using 2 different satellite films as objects, the outdoor reconstructed images were gotten with the Strehl value 0.44 and 0.39 without turbulence, separately, and Strehl value 0.43 and 0.38 with turbulence, separately. Compared the reconstructed images of outdoor with lab, the conclusion was gained that libration had obvious effect on imaging. The result that the Strehl value of outdoor imaging was similar to lab imaging confirmed the fact that Fourier telescopy imaging was immune to down-link atmospheric turbulence..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1317 (2011)
Compressive Imaging Using Toeplitz-circulant-block Phase Mask Matrices
ZHANG Cheng, YANG Hai-rong, and WEI Sui
Toeplitz-Circulant-Block phase mask matrices are proposed to implement image acquisition based on Toeplitz and Circulant matrices. Simulation results show that novel phase mask matrices can effectively capture the information of image with a significant reduction of measurements. The new research of phase mask matricesToeplitz-Circulant-Block phase mask matrices are proposed to implement image acquisition based on Toeplitz and Circulant matrices. Simulation results show that novel phase mask matrices can effectively capture the information of image with a significant reduction of measurements. The new research of phase mask matrices provides more supports for deterministic measurement in the application of compressive imaging. Due to its specific structure, the proposed matrices have more advantages than Toeplitz and Circulant matrices, reduce the difficulty and costs of the physical realization, and provide some theoretical, computing and technical support for new design of camera..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1322 (2011)
Propagation of Optical Wave with Phase Perturbed by Continuous Spectrum and Generation of Pulse Trains in Optical Fibers with Quintic Nonlinearity
ZHONG Xian-qiong, XIANG An-ping, and CHENG Ke
According to the extended nonlinear Schrdinger equation including quintic nonlinearity in optical fibers, modulation instability (MI) based generation of high-repetition-rate optical pulse trains is numerically demonstrated by using the optical wave with its phase perturbed by Gaussian-typed continuous spectrum insteaAccording to the extended nonlinear Schrdinger equation including quintic nonlinearity in optical fibers, modulation instability (MI) based generation of high-repetition-rate optical pulse trains is numerically demonstrated by using the optical wave with its phase perturbed by Gaussian-typed continuous spectrum instead of conventional monochromatic one. The results show that, the pulse trains can also be generated due to MI effect like the conventional case. However, being different from the conventional case, the generated pulse trains here consist of limited number of pulses which are generally not equal in width, intensity, and interval. And the pulse number increases with the propagation distance. Moreover, when the other parameters are the same, the positive quintic nonlinearity can make the pulse width and interval shorten, which means that the positive quintic nonlinearity is beneficial to generate higher repetition rate pulse trains. While the negative one takes the opposite. The numerically calculated chirps developed during the generation process of pulse trains indicate that, both the chirps and their variations with the distance are highly nonmonotonic, and the quintic nonlinearity will change both the chirp range and the chirp amount..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1328 (2011)
Effects of Z-scan Parameters on the Third-order Nonlinear Optical Properties of Films Materials
GAN Ping, QING Sheng-lan, and XIAN Xiao-dong
Parameters about Z-scan measurements of thin films were investigated using numerical methods. Differences of the magnitude of Z-scan′s third-order nonlinear refractive index and absorption coefficient were observed under different laser pulse duration using numerical simulation. The more obvious peak-valley features ofParameters about Z-scan measurements of thin films were investigated using numerical methods. Differences of the magnitude of Z-scan′s third-order nonlinear refractive index and absorption coefficient were observed under different laser pulse duration using numerical simulation. The more obvious peak-valley features of Z-scan′s closed-aperture curve were observed with the smaller aperture hole by simulating under aperture radius for different hole. The more obvious peak-valley features of Z-scan′s closed-aperture curve were observed by simulating under different distances of aperture lens to focus, when distance is 1/2 lens focal length. The experimental results reported in the literature related agree well with the theoretical analysis. The results have some significance to the measurement of Z-scan with films..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1333 (2011)
A Coating Design Method Based on Particle Swarm Optimization
ZHAI Zi-yu, and YE Mei-ying
Particles swarm optimization is a new evolutionary computation technique.Compared with genetic algorithm，the particles swarm optimization has the advantages of easy implement，few control parameters，and fast convergence to optimal solution in most cases.In order to obtain better multilayer coating structure，the particleParticles swarm optimization is a new evolutionary computation technique.Compared with genetic algorithm，the particles swarm optimization has the advantages of easy implement，few control parameters，and fast convergence to optimal solution in most cases.In order to obtain better multilayer coating structure，the particles swarm optimization is proposed for the design of optical multilayer coatings.To verify the feasibility of the method，three different design examples，i.e.，anti-reflection film，hign-reflection film and beam-splitting film，were demonstrated.In the examples，the sum of squared error of ideal reflectivity and actral reflectivity was used as the merit function of multilayer coating performance.The results indicate that the particles swarm optimization is an effective technique for the design of multilayer coatings.By means of particles swarm optimization，a better multilayer coating structure than genetic algorithm can be obtained under the same design condition..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1338 (2011)
Fabrication and Electrical Properties of Highly Preferred Orientation Mo Thin Film by DC Magnetron Sputtering
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Mo thin film was prepared on glass substrate by DC magnetron sputtering method. Effects of the craft on the structure,morphology and electrical performance of Mo thin film were studied by X-ray Diffraction Analysis,Atomic Force Microscope and Four-point Probe System,respectively.It was found that the Mo thin film was gMo thin film was prepared on glass substrate by DC magnetron sputtering method. Effects of the craft on the structure,morphology and electrical performance of Mo thin film were studied by X-ray Diffraction Analysis,Atomic Force Microscope and Four-point Probe System,respectively.It was found that the Mo thin film was grown with (211) preferred orientation at 150℃,and (110) preferred orientation in other temperature conditions. The roughness of the sample did not change significantly with the increase of substrate temperature, which is about 0.35 nm，but increased with the increase of sputtering power density. On the other hand,the resistivity of the thin film decreased in an almost exponential decay with the increase of sputtering power density,and decreased and then increased with the increase of substrate temperature. Moreover it was reduced to the minimum of 2.02 × 10-5Ω·cm at 150 ℃..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1342 (2011)
Design of Zoom Lens System Based on Digital Signal Processing
LI Ling-yin, WANG Yi-fan, and XUE Yu
Aiming at slow response speed and low accuracy of traditional continuous zoom lens control system, the design method of continuous zoom lens and its control system was improved. Magnifier compensation displacement curve was found using mechanical compensation theory. Based on control techniques of digital signal procesAiming at slow response speed and low accuracy of traditional continuous zoom lens control system, the design method of continuous zoom lens and its control system was improved. Magnifier compensation displacement curve was found using mechanical compensation theory. Based on control techniques of digital signal processing (DSP) and stepping motor, a control system was designed including DSP, stepping motor, stepping motor driver, keyboard control, computer communication and LCD block. Meanwhile self-locking blocks were added to promote safety and reliability of the control system. The experimental results show that the control system accuracy is within 0.01 mm and achieves the technical requirement of 0.12 mm..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1346 (2011)
Automated Optimization of Free-form Surface Lens for LED Collimation
LUO Xiao-xia, LIU Hua, LU Zhen-wu, JING Lei, JIANG Yang, and Xin Di
In order to achieve full light utilization and satisfy the demand for far-field illuminance of LED, automated optimization method in sequential mode of ZEMAX was proposed in the design of collimator with far-field illuminance for LED source. The system was established in ZEMAX′s multiple configurations, and the user deIn order to achieve full light utilization and satisfy the demand for far-field illuminance of LED, automated optimization method in sequential mode of ZEMAX was proposed in the design of collimator with far-field illuminance for LED source. The system was established in ZEMAX′s multiple configurations, and the user defined merit function was written out using ZEMAX Programming Language (ZPL) macros language. In the simulation, the material of lens is PMMA and the source is Lambertian-type LED light source, of which divergence angle is 180°. Optimum parameters of collimator were obtained via running an optimization. The optical simulation results show that an efficiency of 87% is achieved under a view angle of ±0.1° and for a point LED source..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1351 (2011)
Design and Experiment of Digital Mcro-mirror Spectrometer Optical System
MO Xiang-xia, WEN Zhi-yu, ZHANG Zhi-hai, and GUO Yuan-jun
A compact, low cost, high speed, non-destructive testing NIR (near infrared) spectrometer optical system is developed based on digital micro-mirror device (DMD). The application of DMD as wavelength scanning element in a traditional lens optical system enables the design of compact grating spectrometers capable of acquA compact, low cost, high speed, non-destructive testing NIR (near infrared) spectrometer optical system is developed based on digital micro-mirror device (DMD). The application of DMD as wavelength scanning element in a traditional lens optical system enables the design of compact grating spectrometers capable of acquiring full spectra using a single detector element. Firstly, comparing with the traditional optical system, there is a new structure with a single detector. With the characteristics of DMD, the structure of the spectrometer system is proposed. After calculating the parameters of the optical path, ZEMAX optical software is used to simulate the system. Finally, the prototype is fabricated and calibrated. Designed for a wavelength range between 900 nm~1 500 nm, the spectrometer optical system features a spectral resolution of 19nm with the area of 70 mm×130 mm. If the width of slit is more than 200 μm, decreasing its width can increase the resolution of this prototype and the change of intensity is slow. Adding an aperture in the prototype can reduce the curved of the slit image in the spectrum. The system satisfies the demand of Near Infrared(NIR) micro spectrometer with a single detector..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1356 (2011)
Method of Two-position Spherical Testing
PENG Jian-hua, SHEN Yi-bing, WANG Kai-wei, and LIU Yong
Three-position absolute surface testing technology can be simplified to method of two-position surface testing under some certain conditions.Based on the study of three-position absolute surface testing technology,a new method of two-position spherical testing via Fizeau interferometer is proposed.The method respectiveThree-position absolute surface testing technology can be simplified to method of two-position surface testing under some certain conditions.Based on the study of three-position absolute surface testing technology,a new method of two-position spherical testing via Fizeau interferometer is proposed.The method respectively assumes that the surface error of reference surface or test surface only contains aberrations with even symmetry.Results show that λ/30 PVr surface error can be measured though two-position testing as well as the method is repeatable to λ/300 PVr and λ/4000 RMS.Besides,the distribution of surface error measured through two-position testing is very close to one measured though three-position testing.The PVr difference is less than λ/300 and the RMS difference is less than λ/2500.So under certain assumptions,experimental device and process can be simplified through two-position testing method,while the accuracy and repeatability can be maintained..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1361 (2011)
Influence of Test Mirror′s Misalignment on High Reflectivity Measurement with Cavity Ring-down Technique
QU Zhe-chao, LI Bin-cheng, and HAN Yan-ling
In the measurement of reflectivity and uniformity distribution of large-aperture optical component, using optical feedback cavity ring-down technique, 2-dimensional scan is required. Angular misalignment of the test component, which is induced during the scanning process, will influence the measurement accuracy. Based In the measurement of reflectivity and uniformity distribution of large-aperture optical component, using optical feedback cavity ring-down technique, 2-dimensional scan is required. Angular misalignment of the test component, which is induced during the scanning process, will influence the measurement accuracy. Based on the augmented matrix of the misalignment of optical resonator, the position of the light spots on the output cavity mirror and the influence on the high reflectivity measurement were calculated in the condition of the symmetric confocal resonator and stable resonator. In the symmetric confocal resonator, there was no drift of the odd light spots, while the drift of the even light spots was a constant for one angular misalignment. In the stable resonator, the drift of the odd and even light spots were reciprocating swing. The results show that the influence of the angular misalignment on the high reflectivity measurement is related to the position of the component and the cavity length. The methods of reducing the influence of the angular misalignment of the component on the measurement results are also presented..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1366 (2011)
Influence of Laser Pulse Width on Backward Detection of Long-distance Wake Bubbles
HAN Biao, LIU Ji-fang, ZHOU Shao-jie, MA Lin, WANG Xu, and LIU Kun-lun
In order to analyze influnce of laser pulse width on backward detection of long-distance wake bubbles, firstly, a simulated model is built to analyze the time-domain characteristics of the laser pulse′s backscttering signal underwater with Monte Carlo method based on Fournier Forand volume scattering function. Using thIn order to analyze influnce of laser pulse width on backward detection of long-distance wake bubbles, firstly, a simulated model is built to analyze the time-domain characteristics of the laser pulse′s backscttering signal underwater with Monte Carlo method based on Fournier Forand volume scattering function. Using this model, the variation of laser pulse′s backscttering signal by long-distance ship wake bubbles underwater with the width of initial laser pulse is studied. The result shows that, with the increase of the width of laser pulse, the outline of scattering signal by water and echo signal by wake bubbleds in backscattering signal become vague. When the width increases to a certain size, the echo signal cannot be distinguished from backscattering signal. In addition, with the decrease of the scattering intensity of bubbles or the distance between bubbles and detector, the variation becomes more evident. Finally, according to analysis results, a method is presented to extract the echo signal by wake bubbles based on inverse convolution..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1372 (2011)
Spontaneous Parametric down Conversion in Type-I BBO Crystal Pumped by Femtosecond Pulses
YIN Juan-juan, YU Kan, and BAO Jia-qi
Spontaneous parametric down conversion of the femtosecond pulse with a type-I β-barium borate (BBO) crystal was studied experimentally, which induced to the generation of colored conical emission (CCE). The influence of parametrics on the conversion efficiency and the characteristics of CCE was discussed in detail. ExpSpontaneous parametric down conversion of the femtosecond pulse with a type-I β-barium borate (BBO) crystal was studied experimentally, which induced to the generation of colored conical emission (CCE). The influence of parametrics on the conversion efficiency and the characteristics of CCE was discussed in detail. Experimental results show that the green conical emission has the biggest divergence angle, which is consistent with the calculation results based on the phase matching condition. When the pumped beam is incident on-axis, the intensity of the CCE will become stronger with the increase of the pump intensity and the thickness of crysta, and the center wavelength of the biggest diverging angle conical emission will change toward long wave. CCE and super-continuum emission can also be observed with different polarization directions..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1376 (2011)
Surface Plasmon Polaritions Lithography Based on Thick Metallic Slit Arrays
XIAO Xiao, XIAO Zhi-gang, XU De-fu, DENG Chi, and LIU Xiao-yun
A surface plasmon polaritons lithography model was presented based on thick metallic slit arrays to fabricate aperiodic nanostructures. The excitation of surface plasmon polaritons, model selection in thick metallic slit arrays and the intensity distribution in photoresist were studied carefully with finite-difference A surface plasmon polaritons lithography model was presented based on thick metallic slit arrays to fabricate aperiodic nanostructures. The excitation of surface plasmon polaritons, model selection in thick metallic slit arrays and the intensity distribution in photoresist were studied carefully with finite-difference time-domain method. The results show that the diffusion of surface plasmon polaritons on slits can be inhibited, and the exposure depth is enhanced by optimizing the slits structure and matching medium lay. So periodic and aperiodic nanostructures are able to be produced by this technology. This may be helpful to fabricating nanostructures by laser direct writing technology..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1381 (2011)
Entanglement Properties in the System of Two Atoms Trapped in Two Distant Cavities Connected by an Optical Fiber
LU Dao-ming
Two two-level atoms are separated in two initially empty cavities that are connected by an optical fiber. The temporal evolution in the entanglement between the cavities as well as between the atom and the local cavity mode were investigated. The influence of the state-selective measurement on the entanglement and thatTwo two-level atoms are separated in two initially empty cavities that are connected by an optical fiber. The temporal evolution in the entanglement between the cavities as well as between the atom and the local cavity mode were investigated. The influence of the state-selective measurement on the entanglement and that of atom-cavity coupling coefficient on the entanglement were discussed. The results show that the entanglement between the cavities as well as between the atom and the local cavity mode can be strengthened through the state-selective measurement on the atom..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1386 (2011)
Tensor Product State Capacity of Non-interacting Fermion Quantum Channel
PENG Yong-gang, and GONG Long-yan
The physical model of non-interacting fermion quantum channel is proposed by fermionic linear optics.Based on covariance matrix property of even Gaussian state and majorization theory,a formula of fermion quantum channel minimum output entropy for even Gaussian input state is deduced.A output entropy correspondence betThe physical model of non-interacting fermion quantum channel is proposed by fermionic linear optics.Based on covariance matrix property of even Gaussian state and majorization theory,a formula of fermion quantum channel minimum output entropy for even Gaussian input state is deduced.A output entropy correspondence between Gaussian state and even Gaussian state is established by adding one extra fermionic mode to n-qubit fermion system.A formula of tensor product state capacity for non-interacting fermion channel is deduced according this output entropy correspondence and under assumption that minimum output entropy is achieved on a Gaussian input state.For fermionic channel correct of proposed minimum output entropy formula is confirmed by the iterative minimization algorithm of output entropy.The numerical results is that for non-interacting fermion noisy quantum channel the proposed formula agrees with the numerical results with a precision about 10e-9..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1392 (2011)
Variant Measures and Visualized Statistical Distributions
ZHENG Jeffrey, and ZHENG Chris
Using measure model and statistical approches to simulate quantum interaction on binary level systems, multiple interactive conditions are simulated via double path interference measures. From quantum interaction, Einstein, Mach-Zehnder, Stern-Gerlach and CHSH measuring parameters are investigated. Using multiple variaUsing measure model and statistical approches to simulate quantum interaction on binary level systems, multiple interactive conditions are simulated via double path interference measures. From quantum interaction, Einstein, Mach-Zehnder, Stern-Gerlach and CHSH measuring parameters are investigated. Using multiple variable logic functions and variant principle, N bit vectors of 0-1 input/output pairs form variant quaternion to establish variant double path simulation model. Using probability, symmetry/anti-symmetry, sychronous/asychronous conditions, simulation system generates two groups of eight histograms to express their statistical distributions in relevant conditions..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1397 (2011)
A Full-parallax Compact Three Dimensional Display System Based on Spliced View-field
PENG Yi-fan, LI Hai-feng, LIU Xu, and LI Shuai
A novel full-parallax 3D display approach and image generating algorithm are demonstrated. The display system employs a panel display monitor, an array of mini-projectors, a rear projecting light beam and a special orthogonal diffuser. Image generation program is operated based on OpenGL programming. In order to validaA novel full-parallax 3D display approach and image generating algorithm are demonstrated. The display system employs a panel display monitor, an array of mini-projectors, a rear projecting light beam and a special orthogonal diffuser. Image generation program is operated based on OpenGL programming. In order to validate the proposed theory based on spliced view-field, a compact prototype-equipment with LCD, Fresnel lens, directional diffuser and rear projecting structure is proposed. The 3D images and dynamic videos displayed by the system can be observed at different horizontal and vertical viewpoints, with more compact size and better use experience..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1405 (2011)
Color Digital Holographic High Quality Reconstruction of Large Size Object
UI Jin-bin, LI Jun-chang, SONG Qing-he, and LOU Yu-li
In order to improve the quality of digital hologram of large size object, a method of recording large size object with a short distance is presented. With spherical wave as reference wave, the digital hologram of large size color object image, which is illuminated with differently wavelengths (red, green, blue), is recIn order to improve the quality of digital hologram of large size object, a method of recording large size object with a short distance is presented. With spherical wave as reference wave, the digital hologram of large size color object image, which is illuminated with differently wavelengths (red, green, blue), is recorded by using of optic system with negative lens. Then each monochromatic holographic image is reconstructed with the same magnification, and the corresponding digital color holographic image is acquired by accurately synthesizing the reconstructed monochromatic images. In order to improve quality of reconstruction image, two elimination zero-order methods are proposed. At first, the zero-order is eliminated with two recorded hologram, and SLM is used to change the record parameters. And the zero-order and conjugate images are eliminated by using “no disturb hologram” in another method. The result will provide a reference in holography application and digital holographic test of large size object..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1409 (2011)
Optimization Method of Reconstruct Wavefront Based on Spatial Light Modulator
HAN Jun, ZHENG Ting, NIE Liang, and AN Yu-ying
A wavefront reconstruction method was proposed based on spatial light modulator (SLM) to achieve the requirement of real-time testing of different aspheric surfaces. An interference measurement system based on SLM wavefront reconstruction was designed, in which the computer-generated hologram (CGH) encoding method was A wavefront reconstruction method was proposed based on spatial light modulator (SLM) to achieve the requirement of real-time testing of different aspheric surfaces. An interference measurement system based on SLM wavefront reconstruction was designed, in which the computer-generated hologram (CGH) encoding method was chosen according to the intrinsic properties of SLM. To resolve the quality degradation problem of the reconstructed wavefront, a dislocation optimization method was proposed. The process is verified through simulation, and the results showed that the RMS of the reconstructed wavefront was improved by 4.45 times..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1413 (2011)
A Novel Algorithm for Single Image Dehazing
HUANG Li-hong
A novel algorithm for single image dehazing was proposed. Firstly，the color space is converted from RGB to HIS after the image normalization. The quadtree-segmentation is applied in hue component divided the image into elementary square units which had the same scene depth. The local airlight could be estimated from eaA novel algorithm for single image dehazing was proposed. Firstly，the color space is converted from RGB to HIS after the image normalization. The quadtree-segmentation is applied in hue component divided the image into elementary square units which had the same scene depth. The local airlight could be estimated from each square unit. To employ the characteristics of fog, the effects of fog on images are erased by using the optical model of foggy weather. Then the image of the restoration is obtained after the saturation component correction. The main advantage of this algorithm is reat time performance that is can be used in defogging both for color images and gray images. Compared with other algorithms, it is shown that this algorithm is able to restore foggy images effectively..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1419 (2011)
Vision Cell Response Model for Small Target Complex Background Suppression
QIN Han-lina, Wei Gui-fenga, ZHOU Hui-xina, LAI Ruib, and LIU Shang-qiana
To improve detection performance for weak and small targets signal in complex infrared background, such as the ground and the cloud, a dim and small target background suppression method is presented based on vision cell response model was presented. Firstly, according to simple cell receptive field model, original infrTo improve detection performance for weak and small targets signal in complex infrared background, such as the ground and the cloud, a dim and small target background suppression method is presented based on vision cell response model was presented. Firstly, according to simple cell receptive field model, original infrared image is decomposed to two images with different Gabor functions using convolution. And then, the function of nonlinear convergence of complex cell response is used to fusion two images obtained for separation small target with background clutter in infrared image. Finally, target image is obtained by using classical adaptive thresholding method. Several groups of experimental results demonstrate that the proposed method can segment the infrared target image effectively, compared with several classical infrared dim and small target background suppression methods, such as local means remove and max median filter methods..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1423 (2011)
Distributed Fiber Optic Brillouin Sensing Technique with Frequency Shifting
HUANG Min-shuang, and HUANG Jun-fen
A novel method to implement distributed fiber optic Brillouin sensing was proposed, using the frequency shifting technique via a Brillouin fiber optic ring cavity. The method is based on the Brillouin optical time-domain analysis (BOTDA) principle that a laser beam from single-longitudinal model lasing is divided into A novel method to implement distributed fiber optic Brillouin sensing was proposed, using the frequency shifting technique via a Brillouin fiber optic ring cavity. The method is based on the Brillouin optical time-domain analysis (BOTDA) principle that a laser beam from single-longitudinal model lasing is divided into two beams; one beam is launched into the Brillouin fiber optic ring cavity to generate the stimulated Brillouin scattering wave of narrow bandwidth as the Stokes wave, the other one is taken as the pump wave through phase modulation at a low frequency; the Stokes and the pump waves counter-propagate along the sensing fiber optic and the Brillouin frequency spectrum is measured to get the temperature or strain in fiber optic. The proposed method translates a microwave frequency signal into a MHz frequency signal for detection and processing with only one laser. The system is simple in structure with low cost and can eliminate the impact of the laser frequency fluctuation on the measurement precision. Experiments show that the method is feasibe..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1428 (2011)
Fabrication of Temperature-insensitive Twist Sensor Using Low Birefringent Photonic Crystal Fiber Based Sagnac Interferometer
ZU Peng, XIANG Wang-hua, and JIN Yong-xing
The circular birefringence effect in the low birefringent photonic crystal fiber caused by fiber twist is investigated,which is applied in the Sagnac interferometer structure to realize a twist sensor.The mechanical force is applied on the photonic crystal fiber in the Sagnac loop to introduce initial linear birefringeThe circular birefringence effect in the low birefringent photonic crystal fiber caused by fiber twist is investigated,which is applied in the Sagnac interferometer structure to realize a twist sensor.The mechanical force is applied on the photonic crystal fiber in the Sagnac loop to introduce initial linear birefringence and to generate a sinusoidal interference spectrum.Then,the dip wavelength of the spectrum shifts due to extra circular birefringence caused by the fiber twist.The relationship between the dip wavelength and twist angle follows Sinc function,which is in coincidence with the therical analysis.The achieved sensitivity and resolution of the sensor are 1.00 nm/(°) and 0.01°,respectively.The sensor possesses ultralow temperature coefficients of －0.5 pm/℃..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1433 (2011)
Photoemission Mechanism of Multi-alkali Cathode
LI Xiao-feng, LIU Ru-biao, and ZHAO Xue-feng
Fluorescent spectra between multi-alkali cathode with Cs-Sb surface layer and without Cs-Sb surface layer were compared. It was found that phenomena of peak wavelength of the fluorescent spectrum shifted to shorter wavelength and intensity of fluorescent spectrum became stronger for the multi- alkali cathode with Cs-SbFluorescent spectra between multi-alkali cathode with Cs-Sb surface layer and without Cs-Sb surface layer were compared. It was found that phenomena of peak wavelength of the fluorescent spectrum shifted to shorter wavelength and intensity of fluorescent spectrum became stronger for the multi- alkali cathode with Cs-Sb surface layer. This phenomenon shows that in the condition of a multi-alkali cathode with Cs-Sb surface layer, the surface work function of multi-alkali cathode is reduced, and Na2KSb structure is changed. This means that in the conditions of the same frequencies and the same incident power irradiation, Na2KSb with Cs-Sb surface layer can be excited more transition electrons and obtain higher transition energy levels. So they are able to escape the multi- alkali cathode surface more easily and have higher probability to access the vacuum .This will lead to higher cathode sensitivity and shows that the Cs-Sb surface layer has a surface effect and physical effects. To further increase the sensitivity of multi-alkali cathode, it is needs to improve the performance of Na2KSb layer in addition to further reduce surface work function of the multi-alkali cathode, so that the same power and frequency of incident light can produce more transition electrons and higher energy transition levels, which needs to further process improvements to make Na2KSb material better..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1438 (2011)
Robust Real-time Electronic Image Stabilization Based on Feature Matching and Checking
PENG Xiao-jiang, and ZHANG Jia-shu
A robust real-time electronic image stabilization algorithm was proposed based on feature matching and checking. In the algorithm, feature points in reference and current frame were extracted by Kanade-Lucas-Tomasi corner detector and matched by the sum of absolute difference criterion firstly. In the process of checkiA robust real-time electronic image stabilization algorithm was proposed based on feature matching and checking. In the algorithm, feature points in reference and current frame were extracted by Kanade-Lucas-Tomasi corner detector and matched by the sum of absolute difference criterion firstly. In the process of checking, a spatial location invariant criterion was presented to delete those points which were error-matching or appeared in foreground moving objects effectively. Finally, the global motion vector was computed by least-squares algorithm in similarity motion model and applied to compensate. Experimental results show that this algorithm is able to meet the requirement in real time and has good performance to the translation, rotation and zoom, and is robust to foreground moving objects..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 40, Issue 9, 1442 (2011)
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