Journals >Acta Photonica Sinica
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2015
Volume: 44 Issue 12
26 Article(s)
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Research Article
Calibration of Mirror Reflectivity for Cavity Enhanced Absorption Spectroscopy
DUAN Jun, QIN Min, LU Xue, SHEN Lan-lan, FANG Wu, XIE Pin-hua, and LIU Wen-qing
To calibrated the reflectivity of the mirrors in optical cavity, two methods of the calibration of mirror reflectivity, which are through a known concentration of an absorber and the difference of Rayleigh scattering, respectively, were introduced and compared. The reflectivity of the same pair of the highly reflectingTo calibrated the reflectivity of the mirrors in optical cavity, two methods of the calibration of mirror reflectivity, which are through a known concentration of an absorber and the difference of Rayleigh scattering, respectively, were introduced and compared. The reflectivity of the same pair of the highly reflecting mirrors were calibrated by these two methods. The reflectivity of the highly refecting mirrors are both 0.99962 to 0.99990 between the spectrum range of 359~380 nm, the linear correlation is 0.998, the results showed the good correlation. The atmospheric NO2 concentrations were simultaneously measured by the cavity enhanced absorption spectrocopy instrument and a commercial nitrogen-oxide analyzer to verify the accurate of calibration of the mirror reflectivity..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1201001 (2015)
Polarization Properties of Gaussian Schell-Model Beams Propagating through Ocean Turbulence
ZHANG Qin-wei, LI Wen-dong, GU Yong-jian, JIN Ming-wei, and XUE Cheng
Based on the generalized Huygens-Fresnel diffraction principle and the unified theory of coherence and polarization of light beams, the polarization change of Gaussian Schell-model beams propagating through the Kolmogorov ocean turbulence was studied, and the conditions of keeping the polarization properties of GaussiaBased on the generalized Huygens-Fresnel diffraction principle and the unified theory of coherence and polarization of light beams, the polarization change of Gaussian Schell-model beams propagating through the Kolmogorov ocean turbulence was studied, and the conditions of keeping the polarization properties of Gaussian Shell-model beams were analyzed in the Kolmogorov ocean turbulence. The polarization propagating properties of linearly polarized light and circularly polarized light were studied in the ocean turbulence. The results show that the completely polarized light is not affected in the Kolmogorov ocean turbulence..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1201002 (2015)
Wavelet Packet Transform for PAPR Reduction Performance in CO-OFDM System
TONG Zheng-rong, GUO Zun-li, CAO Ye, and ZHANG Wei-hua
Due to the high peak to average power ratio in coherent optical orthogonal frequency division multiplexing system, a coherent optical orthogonal frequency division multiplexing system using the wavelet packet transform instead of the traditional fast Fourier transform was proposed. Simulation results show that the noveDue to the high peak to average power ratio in coherent optical orthogonal frequency division multiplexing system, a coherent optical orthogonal frequency division multiplexing system using the wavelet packet transform instead of the traditional fast Fourier transform was proposed. Simulation results show that the novel transformation has obvious inhibiting effect on peak to average power ratioand and gets better bit error rate performance than the traditional system using fast Fourier transform. With symmetry of the wavelet scaling function and wavelet function improving, the ability to avoid the phase shift improves in the process of signal processing and system performance ameliorates.At the complementary cumulative distribution function of 0.01, peak to average power ratio of using haar wavelet function can be optimized 2 dB and the optical signal to noise tatio of haar is improved by 1.5 dB at bit erro rate of 10-3 compared with that of traditional fast Fourier transform. On the basis of research, with the simpler algorithm structure, lifting wavelet transform instead of Mallat algorithm was proposed to apply to the coherent optical orthogonal frequency division multiplexing system system and the inhibition peak to average power ratio and bit erro rate performance is similar to the latter system..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1206001 (2015)
Magnetic Field Sensing Based on Magnetic-fluid-clad No-core Single-mode No-core Fiber Structure
Pu Shengli, Tang Jiali, Liu Zhiheng, and Luo Longfeng
A kind of magnetic field sensing structure based on magnetic-fluid-clad no-core single-mode no-core fiber was proposed and designed. The no-core fiber in this structure can excite cladding mode and combine the core and cladding modes of the intermediate sensing single-mode fiber. The transmission spectra of the as-fabrA kind of magnetic field sensing structure based on magnetic-fluid-clad no-core single-mode no-core fiber was proposed and designed. The no-core fiber in this structure can excite cladding mode and combine the core and cladding modes of the intermediate sensing single-mode fiber. The transmission spectra of the as-fabricated sensing structures at different external magnetic field strengths and ambient temperatures were investigated experimentally. The corresponding magnetic field sensing properties and influence of ambient temperature were obtained. Experimental results indicate that the valley wavelengths at around 1 462 nm and 1 477 nm shift to long wavelength side with the increase of external magnetic field. The achieved sensitives are 67.28 pm/Oe and 49.82 pm/Oe, respectively. The valley wavelength at around 1 462 nm shifts to short wavelength side with the temperature increase and the corresponding sensitivity is 37.8 pm/℃. The proposed sensing structure possesses the advantages of easiness of fabrication and high sensitivity, which is promising for future pragmatic applications..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1206002 (2015)
Research on the Axial Magnetic Characteristic in a Polarization Maintaining Fiber Optic Gyroscope
ZHANG Cai-ni, YANG Meng-fang, ZHAO Yu-xiang, ZHANG Deng-wei, SHU Xiao-wu, and LIU Cheng
The output characteristics of polarization maintaining fiber optic gyro were studied in the influence of the axial magnetic field parallel to the sensitive axis of the sensing coil. The mathematical model of the relationships between the nonreciprocal phase difference in polarization maintaining fiber optic gyro and thThe output characteristics of polarization maintaining fiber optic gyro were studied in the influence of the axial magnetic field parallel to the sensitive axis of the sensing coil. The mathematical model of the relationships between the nonreciprocal phase difference in polarization maintaining fiber optic gyro and the polarization state of incident light was established and verified by experiments. The results show that the drift caused by the magnetic field in the polarization maintaining fiber optic gyroscope come from the fiber’s bending when coil is wounded, and the drift is closely related with the distribution of the fiber in the coil. The sensibility will not change after the sensing coil is completely manufactured because of the invariant distribution of the fiber twist. By changing polarization state of the incident light to some extent, the sensitivity of the axial magnetic field of polarization maintaining fiber optic gyro can be changed..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1206003 (2015)
Quadrature Demodulation in a Laser-interception System Based on Acousto-optic Frequency Shifting
HE Ning, FENG Tai-qin, and LIAO Xin
According to modulation and transmission characteristics of laser interception, a laser- interception system based on Doppler frequency shift was put forward. The theory of Doppler frequency shift was studied, and the optical coherent balanced detection and quadrature demodulation were discussed. The effects of anti-noAccording to modulation and transmission characteristics of laser interception, a laser- interception system based on Doppler frequency shift was put forward. The theory of Doppler frequency shift was studied, and the optical coherent balanced detection and quadrature demodulation were discussed. The effects of anti-noise performance and carrier-frequency mismatching on signal recovery were analyzed by numerical simulation and frequency-domain analysis, a technical method for laser coherent balanced interception based on acousto-optic frequency shift was proposed. Experimental results show that noise floor and excess intensity noise can be effectively suppressed by the proposed method, namely signal noise ratio can be improved, and thus non-contact detection for the perturbation at interface generated by acoustic vibration can be realized, which provides an effective technical method for practical application..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1206004 (2015)
Design of Spectroradiometer Incidence System Based on Lightcone Coupling
YANG Li-yan, ZHANG Guo-yu, ZHENG Ru, BIAN Zhen-zhen, ZHENG Feng, and HU Bing
A spectroradiometer incidence system was designed to realize the coupling of direct irradiance. In order to reduce energy loss between light-collecting barrel and fiber, and solve the problem of low energy level in direct coupling, the characteristic dimensions of the barrel were restrained, the lightcone parameters weA spectroradiometer incidence system was designed to realize the coupling of direct irradiance. In order to reduce energy loss between light-collecting barrel and fiber, and solve the problem of low energy level in direct coupling, the characteristic dimensions of the barrel were restrained, the lightcone parameters were calculated according to the geometrical optics theory. The coupling efficiency in different wavelengths and change of efficiency under different tracking angle errors were tested by solar simulator. The theory analyses indicate that axis’s lateral offset of lightcone and fiber is the main factor that caused coupling efficiency loss. Experimental results indicate that the coupling efficiency of the whole system is 66.24%, the efficiency is 12.8% when the sun tracker miss the sun completely, which reflects the level of circumsolar radiation and scattered radiation. The system can satisfy the requirements for the observation of direct solar irradiation..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1206005 (2015)
Quantitative Evaluation of Jamming Effect on Spectral Imaging Based on Spectral Similarity Measure
GAO Wei, SUN Yi-fan, SUN Peng, and DANG Dong-ni
Spectral imaging camouflage jamming tests were carried out with a kind of broad-band camouflage net and a hyperspectral imager. Based on the change of spectral characteristics of the spectral image data after being jammed, a spectral-distance criterion for evaluating jamming effect on spectral imaging was proposed by uSpectral imaging camouflage jamming tests were carried out with a kind of broad-band camouflage net and a hyperspectral imager. Based on the change of spectral characteristics of the spectral image data after being jammed, a spectral-distance criterion for evaluating jamming effect on spectral imaging was proposed by using spectral similarity measure. The applicability of the criterion was verified and analyzed with the data of the camouflage jamming tests. The results show that, under the test conditions, in the areas those are camouflaged effectively, the spectral distance between the spectral vectors of the image units before and after being camouflaged can reach 0.14~0.5 . The amplitude value varies with the change of the target characteristics before being camouflaged, camouflage net layers and the gain of the hyperspectral imager. On the other hand, the spectral distance of the image units remains below 0.05 in the non-camouflaged areas or the areas those are camouflaged ineffectively. Thus the spectral distance of the image units in camouflaged areas is usually larger than that of the image units in non-camouflaged areas remarkablely when the target is camouflaged effectively. The more remarkable the camouflage effect, the larger the spectral distance. Therefore the spectral distance between the spectral vectors of the image unit before and after being jammed can reflect the jamming effect on the spectral characteristics of the image unit quantitatively, and discriminate small differences in jamming effect on spectral imaging reliably. So the spectral distance could be used as an index for evaluating jamming effect on spectral imaging quantitatively and impersonally..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1211001 (2015)
Wavefront Gradient Deviation Evaluation Methods
SONG Shu-mei
In order to evaluate wavefront of imaging systems, the wavefront gradient deviation evaluation methods were proposed, which could directly indicate imaging performance. The wavefront gradient deviation is defined as the deviation of image spot and image energy center, and the relative wavefront gradient deviation is thIn order to evaluate wavefront of imaging systems, the wavefront gradient deviation evaluation methods were proposed, which could directly indicate imaging performance. The wavefront gradient deviation is defined as the deviation of image spot and image energy center, and the relative wavefront gradient deviation is the ratio of wavefront gradient deviation to Airy disk radius. The wavefront gradient deviation and relative gradient deviation can be evaluated by image size, image concentration and image energy distribution. Based on dozens of practical wavefront testing results, the evaluations of image concentration and image energy distribution are usually stable enough for different test resolutions. The difference of evaluation results is usually less than 10% for every double or half resolution. An aspherical wavefront and a spherical wavefront with dramatically ripple amount were analyzed to illustrate the relationship of wavefront gradient deviation and wavefront spacial distribution. Relied on the wavefront gradient deviation distribution on exit pupil and wavefront gradient distribution on image plane, it is convenient to operate for optical manufacture and assembling. The wavefront gradient deviation evaluations can be used as the wavefront specifications for quality control..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1211002 (2015)
Reducing the Error Caused by Dynamic Background in the Imaging System Based on Compressed Sensing
ZHUANG Jia-yan, HE Wei-ji, CHEN Qian, and FENG Wei-yi
A algorithm which uses the compensation factor to eliminate nonlinear errors was proposed to reduce the nonlinear errors caused by sudden change of background in the imaging system based on compressed sensing. The compensation factor was calculated from the mean value of measured data under different background. The siA algorithm which uses the compensation factor to eliminate nonlinear errors was proposed to reduce the nonlinear errors caused by sudden change of background in the imaging system based on compressed sensing. The compensation factor was calculated from the mean value of measured data under different background. The simulation results show that the proposed algorithm improve the peak signal to noise ratio of reconstructed image from 29.5 dB to 62 dB when the background noise change as many as 300 times during 900 times sampling. The reconstructed image is more readable and the imaging system is more robust with the proposed algorithm..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1211003 (2015)
Method for Electron Density Diagnostics Based on Coded Source Imaging
LI Guo-dong, YANG Jian-lun, and CHEN Fa-xin
A kind of coded-source-imaging-based laser probing diagnostics can be used for the measurements of coronal region electron density in the explosion experiments of wire array Z - pinch. Based on the shadowgraphy system, it just add a linear fringe-pattern mask in front of the target to change the wavefront distribution A kind of coded-source-imaging-based laser probing diagnostics can be used for the measurements of coronal region electron density in the explosion experiments of wire array Z - pinch. Based on the shadowgraphy system, it just add a linear fringe-pattern mask in front of the target to change the wavefront distribution of incident laser. The selection of object plane and extraction of deflection angle are analyzed by imaging simulation. When the maximum density of plasma is an order of magnitude less than the critical density, paraxial approximation can be used in Abel transform. Cubic spline interpolation of deflection angles and piecewise integral of Abel transform give out the density distribution, which is in good agreement with the setted density value. Compared the inversion errors with different line-pairs coded masks, we can get good results for the plasma with smooth gradient even if the mask fringes are relatively sparse. Calculation shows that this method has a simpler system, and don′t need high performance parameters for light source and optical device, thus it has a good measurement adaptability, and it′s feasible for the diagnosis of plasma density..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1211004 (2015)
Using the Equivalent Stress to Analyze the Effect of Temperature Change on Surface Accuracy of the Bonded Mirror
LI Wen-jie, WANG Shao-xin, MU Quan-quan, YANG Chen-liang, CAO Zao-liang, and XUAN Li
The equivalent stress method was proposed to analyze the surface change of the mirror under the temperature change. The forced displacement restrain was applied on the bonded position of the mirror to ensure the mirror suffer the equivalent stress compared with the heat stress. The surface change of the mirror under thThe equivalent stress method was proposed to analyze the surface change of the mirror under the temperature change. The forced displacement restrain was applied on the bonded position of the mirror to ensure the mirror suffer the equivalent stress compared with the heat stress. The surface change of the mirror under the action of the forced displacement was consistent to the one under the action of the temperature change. A bonded experiment to the mirror whose diameter is 70 mm and thickness is 15 mm and surface accuracy of the mirror is measured by the fine ZYGO interferometer in different temperatures. It is indicated that when the temperature descended from 20℃ to 16℃, the mirror surface change of the Peak to Valley(PV) and Root Mean Square(RMS) are 0.005λ and 0.002λ, while the simulation change of the PV and RMS are 0.004λ and 0.002λ. When the temperature increased from 20℃ to 30℃, the mirror surface change of the PV and RMS are 0.013λ and 0.006λ. The simulation change of the PV and RMS are 0.012λ and 0.004λ. The experimental result agrees with the simulation basically, which illustrate the equivalent stress method based on the forced displacement restrain can express the effect of the temperature change on the surface accuracy change of the mirror perfectly..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1212001 (2015)
Partition Algorithm for Extended Targets in Optical Sensor Using Sparse Reconstruction
WANG Xue-ying, WANG Tie-bing, ZHANG Hui, LI Jun, and AN Wei
A partition algorithm method with sparse reconstruction was proposed to partition measurements making full use of the information of the extended targets. The grid sampling of the image plane was carried out by using diffraction limited optical system′s features,a sparse reconstruction model was set up with a “super coA partition algorithm method with sparse reconstruction was proposed to partition measurements making full use of the information of the extended targets. The grid sampling of the image plane was carried out by using diffraction limited optical system′s features,a sparse reconstruction model was set up with a “super complete dictionary”. Effective information in the amplitude of every pixel was extracted by sparse reconstruction, non-target measurement was eliminated by physical features. Partitioning measurements was realized by using the reconstructed sub-pixel-level target location and amplitude information. Simulation results indicate that the proposed method correctly partitions all the targets as separate measurements about 30s earlier than traditional distance-based partitioning method when signal noise ratio is 6 dB. Due to the full and effective use of target information, the proposed method outperforms the traditional distance-based partitioning methods in terms of the partitioning results′ accuracy, especially in the cases of poor signal noise ratio..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1212002 (2015)
Calibration Method for Line Structured-light Parameters Based on Homography Matrix
HONG Lei, TIAN Qi-liang, and JI Bao-jian
The mapping relationship of homography matrix between the image plane and the target plane was calculated by the rectangular corner points, the linear equation of the center line of the structured-light in the target plane was obtained. Based on the vanishing point theory, the coordinates of arbitrary points on structuThe mapping relationship of homography matrix between the image plane and the target plane was calculated by the rectangular corner points, the linear equation of the center line of the structured-light in the target plane was obtained. Based on the vanishing point theory, the coordinates of arbitrary points on structured-light in target line in camera coordinate system was obtained. The light plane equation was fitted by calibration points extracted from multiple images. Experiments show that the method can achieve a fast and an accurate calibration of structured-light plane parameters with the positioning accuracy at 0.437 mm, and suitable for the requirements on industrial field. Compared with the methods based on invariance of cross ratio, the proposed method is more universal which has a higher efficiency to extract calibration points and the target design is more simple..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1212003 (2015)
Development of Driver for Room-temperature Continuous Mid-infrared Quantum Cascade Laser
FU Li, DANG Jing-min, MIAO Chun-zhuang, CHEN Chen, ZHENG Chuan-tao, and WANG Yi-ding
In order to satisfy the capability of driving room-temperature continuous mid-infrared quantum cascade laser based on the mid-infrared wavelength modulation spectroscopy, a novel quantum cascade laser driver was designed and implemented under experimental evaluation. Firstly, a direct-current, a repetitive ramp and a sIn order to satisfy the capability of driving room-temperature continuous mid-infrared quantum cascade laser based on the mid-infrared wavelength modulation spectroscopy, a novel quantum cascade laser driver was designed and implemented under experimental evaluation. Firstly, a direct-current, a repetitive ramp and a sinusoid were generated to tune drive current and to produce a modulation in the wavelength of quantum cascade lasers via a function generation module. Secondly, a comprehensive and high-speed (the response time is about 40 ns) over-current protective circuit was developed in conjunction with the deep voltage negative-feedback theory, which guaranteed the laser operation reliability and improved the stability of drive current. Again, a complete temperature analog control circuit and a proportional-integral-differential software algorithm were combined to simplify the circuit structure and to control and stabilize the laser temperature effectively, which prevented the drift of the laser output wavelength and the fluctuations of the emission power caused by the temperature change. Via the use of the driver, driving tests were carried out on a mid-infrared quantum cascade laser with center wavelength at 4.76 μm, which was fabricated by institute of semiconductors, Chinese Academy of Sciences. Experimental results demonstrated that current regulation linearity of the drive power system is 0.0068%, the stability of drive current during long time (240 h) is 4.99×10-5, the stability of light power is 5.07×10-4, the temperature stability is 0.01℃ and the stable control process is 17s,the drift of wavelength at peak within 240 h is ±0.02 nm when drive current of the quantum cascade lasers is 330 mA and the temperature is 21℃..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1213001 (2015)
Mode Characteristics Analysis of Embedded-type Dual Microdisk Resonators
CHEN Yu-ren, WANG Zhuo-ran, YUAN Guo-hui, and REN Pei-pei
Based on a microdisk resonator device with a diameter of 7.2 μm, the symmetric and asymmetric defects were introduced. By using the finite difference time domain method , the influences of the positions and dimensions of the defects on the resonant modes of microdisks were analyzed. The results show that with the increBased on a microdisk resonator device with a diameter of 7.2 μm, the symmetric and asymmetric defects were introduced. By using the finite difference time domain method , the influences of the positions and dimensions of the defects on the resonant modes of microdisks were analyzed. The results show that with the increase of the radius of defects resonance modes firstly move towards shorter wavelength and then get suppressed progressively. Furthermore, a microdisk was introduced in two kinds of defects to form embedded-type dual microdisk resonators. After the optimization of the relative positions and dimensions, the single-mode resonance is realized at 1 128 nm and 1 109 nm. This device overcomes the drawbacks of single microdisk and simplifies the resonance mode, it can be applied in wider interest fields..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1213002 (2015)
Ultra-Compact Coupling Modulation Based High Speed Electro-optic Modulator with Rectangular Ring Resonator
WANG Shuang, LIU Ke, and ZHANG Cheng-long
In order to solve the mutual restricted problem between modulation bandwidth and high Q value of microring electro-optic modulator which used intracavity index modulation mechanism in the device, an ultra-compact coupling modulation based electro-optic modulator was proposed. This device consists of trench-based frustrIn order to solve the mutual restricted problem between modulation bandwidth and high Q value of microring electro-optic modulator which used intracavity index modulation mechanism in the device, an ultra-compact coupling modulation based electro-optic modulator was proposed. This device consists of trench-based frustrated total internal reflection couplers and 90° waveguide bends. A time domain dynamic model was used to evaluate the device performance, and the results show that the modulation phase change is less than 0.2 π, the state modulation depth is greater than 0.96 (normalized maximum of 1.0), and the modulation bandwidth is greater than 100 GHz. This high speed modulator exhibits a small chip area of 10 μm×15 μm and a lower power consumption. The compact device configuration shown here is beneficial to the extension at two-dimensional directions, and may be potentially utilized in large-scale photonic integrated circuits..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1213003 (2015)
Mode Field Analysis Method of the Planar Optical Waveguides Based on an Integral Equation
LIU Xiao-huan, and LI Bing-xin
The one dimensional wave equation was transformed into space-frequency domain by Fourier transform, and became an integral equation which could be solved by Nystrm method. A solver of standard matrix eigenvalue problem from the integral equation was given by Lapack packages. The dispersion relation and mode fields of The one dimensional wave equation was transformed into space-frequency domain by Fourier transform, and became an integral equation which could be solved by Nystrm method. A solver of standard matrix eigenvalue problem from the integral equation was given by Lapack packages. The dispersion relation and mode fields of a planar dielectric waveguide could be obtained simultaneously. The numerical results showed that the proposed method was flexible for planar optical waveguides with any refractive index profiles and high accuracy only using a low order matrix..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1213004 (2015)
Power Measurement of Ultra-fast Pulse Digital Holography Pump-probe System
YUE Wen-yan, YANG Xiao-ping, and YANG Yong
A method of measuring the lowest energy in the detection system was proposed. The system in which the power of subpulse is equable and the system in which the power of subpulse is inequable were studied by the proposed method, the results show that the energy efficiency of input intensity are 41.3% and 28.8%, respectivA method of measuring the lowest energy in the detection system was proposed. The system in which the power of subpulse is equable and the system in which the power of subpulse is inequable were studied by the proposed method, the results show that the energy efficiency of input intensity are 41.3% and 28.8%, respectively. The threshold energy of the charge-coupled device which used to detect the interference fringe is measured of 56.7 mW by using Mach-Zehnder interferometers. The energy two kinds of detecting systems need are 0.86 W and 1.575 W respectively calculated by the measured energy efficiency and threshold..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1214001 (2015)
Analysis on Effect of Separated Amplifier Structure Parameter on Thermal Effect
ZHANG De-ping, WU Chao, SHI Hui-cai, ZHANG Rong-zhu, and SUN Nian-chun
The thermal effect of the laser diode end-pumped rectangular separated amplifier was studied. Thermal conduction model of Cr,Yb∶YAG/Yb∶YAG composite structure accord with reality was established. In the separated amplified structure, the internal temperature field variation of amplifier under different gain media and cThe thermal effect of the laser diode end-pumped rectangular separated amplifier was studied. Thermal conduction model of Cr,Yb∶YAG/Yb∶YAG composite structure accord with reality was established. In the separated amplified structure, the internal temperature field variation of amplifier under different gain media and cladding structure was analyzed. The temperature distribution inside the material was calculated quantitatively, and the phase distribution of the wave front with the change of temperature was given. The research shows that in the thinner cladding thickness and smaller thickness ratio, medium face has a higher temperature rise, and aggravated thermal effect; the thermal effect of the amplifier is weaken by relative more thick cladding and larger thickness ratio. The research results can provide theoretical guidance to depress the thermal effect of composite structure amplifier..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1214002 (2015)
Fabrication of Multi-structure 2D Photonic Quasicrystals by Using Single-prism Common-path Interferometry
SUN Xiao-hong, LIU Wen-yan, WANG Shuai, LI Wen-yang, and LIU Wei
A simple common-path interfering device used for large-area production of complicated photonic quasicrystals in sub-micron scale was presented. The quasicrystalline structures were designed and their diffraction patterns were obtained to prove the multi-fold rotational symmetry. By using the setup, all kinds of quasicrA simple common-path interfering device used for large-area production of complicated photonic quasicrystals in sub-micron scale was presented. The quasicrystalline structures were designed and their diffraction patterns were obtained to prove the multi-fold rotational symmetry. By using the setup, all kinds of quasicrystals with arbitrary complexity and rotational symmetry can be designed and fabricated. Furthermore, ten-fold quasicrystalline structures were produced experimentally. The atomic force microscope measurements and diffraction patterns reveal the long-range directivity and rotational symmetry. The experimental results show that the quasicrystal has a diameter of 1.2 μm for a ten-fold lattice and 377 nm for a minimum unit. Compared with the theoretical data 1.25 μm and 392.5nm, there is a difference of 4%. A good agreement has been obtained between the experimental and theoretical results. This is promising for the investigation on photonic devices based on the photonic bandgaps..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1216001 (2015)
Fabrication and Characterization of Passive Microsphere Resonators Based on Ge28Sb12Se60 Chalcogenide Glass
ZHANG Xing-di, WU Yue-hao, JIANG Bo, ZHANG Wei, ZHANG Pei-qing, DAI Shi-xun, XU Tie-feng, and ZHANG Qin-yuan
The fabrication and characterization of microsphere resonators was researched based on an arsenic-free chalcogenide glass whose composition can be represented as: Ge28Sb12Se60. Bulk Ge28Sb12Se60 glasses was fabricated and then crushed into powders. Glass powders were fed into a self-developed furnace and were melted inThe fabrication and characterization of microsphere resonators was researched based on an arsenic-free chalcogenide glass whose composition can be represented as: Ge28Sb12Se60. Bulk Ge28Sb12Se60 glasses was fabricated and then crushed into powders. Glass powders were fed into a self-developed furnace and were melted into liquid forms. Molten glass powders were transformed into microspheres due to surface tensions and were cooled/collected in the output of the furnace. Microsphere fabricated in our lab have diameters ranging from 50~200 μm. Two microspheres with diameters of 112.01 μm and 57.63 μm were selected for near field coupling experiments with silica fiber tapers. The microsphere/fiber taper coupling system with a narrow-bandwidth tunable laser was pumped and the spectra of the coupling system for the spectral range of 1 530~1 560 nm was measured. Periodically spaced absorption peaks were clearly noted in the measured spectra, which were attributed to optical resonances happened in corresponding wavelengths due to whispering gallery modes. The spacings of adjacent absorption peaks are 5.22 nm and 2.60 nm for the 112.01 μm and 57.63 μm spheres, which are in good accordance with spacings of first-order WGMs calculated with the classic Mie scattering theory. According to the experimental results, Ge28Sb12Se60 glass can be used as a promising alternative to conventional Arsenic-based chalcogenide glasses for fabricating infrared microsphere resonators, which have important applications in the fields of narrow-bandwidth filters, Raman lasers, and high sensitivity optical sensors..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1216002 (2015)
Quantum Properties of Entangled Biphotons Generated via Frequency-nondegenerate Type-I Spontaneous Parametric Down-conversion
LI Bai-hong, WANG Dou-dou, ZHANG Tao, LIU Wei, and LI Yong-fang
The quantum properties of entangled biphotons generated via frequency-nondegenerate type-I Spontaneous Parametric Down-Conversion (SPDC) were studied in theory, and compared with that of frequency-degenerate type-I SPDC. The properties of spectrum and entanglement of entangled biphotons in both cases were analyzed by tThe quantum properties of entangled biphotons generated via frequency-nondegenerate type-I Spontaneous Parametric Down-Conversion (SPDC) were studied in theory, and compared with that of frequency-degenerate type-I SPDC. The properties of spectrum and entanglement of entangled biphotons in both cases were analyzed by the joint spectral intensity; the property of quantum interference was given by the results of Hong-Ou-Mandel interferometer and Mach-Zehnder interferometer. The results show that, for pulse pumping, the phase-matching function is shown to be asymmetric as a result of frequency-nondegenerate, which leads to entangled biphotons distinguishable and quantum interference visibility was reduced. As the pump bandwidth is increased, this effect becomes more pronounced. For monochromatic pumping, the phase-matching function is shown to be symmetric, which results in maximum entanglement and quantum interference visibility. These results provide a theoretical basis for the applications of frequency-nondegenerate entangled photon source in various quantum information schemes..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1227001 (2015)
The Transmission of Polarized Light of Space Attitude in Quantum Communication
YANG Hai-ma, MA Cai-wen, WANG Jian-yu, ZHANG Liang, LIU Jin, and HUAN Yuan-shen
By using the design of the orthogonal polarized light beacon, the single optical path transmission of space beacons gesture was achieved, which provied the conditions for the Satelite-Ground quantum optical link. The transmission characteristic of the polarization through the optical device, especially the coated devicBy using the design of the orthogonal polarized light beacon, the single optical path transmission of space beacons gesture was achieved, which provied the conditions for the Satelite-Ground quantum optical link. The transmission characteristic of the polarization through the optical device, especially the coated device was analyzed. A simulation was done to analyze the outgoing beacon light under the condition of the different incident angles and rotation angles. The influence by the phase and reflectivity difference in the optical components was analyzed. A mathematical model of the measurement of polarization azimuth by using the Jones matrix was made to analyze the form of the Malus law in the elliptic polarized light incident. Three-dimension attitude can be obtained by a single Position Sensitive Detector sensor which can receive the beacon light, decouple the angle of polarization and the location of incident light. The experiment data shows that the system has the function of measuring three-dimension attitude of the beacon by a single Position Sensitive Detector sensor. This system provides a solution to the fields of the Satelite-Ground Optical Communication and the measurement of space geometry position..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1227002 (2015)
Classification of Hyperspectral Remote Sensing Images Based on Supervised Sparse Manifold Embedding
HUANG Hong, YANG Ya-qiong, LUO Fu-lin, and FENG Hai-liang
Sparse Manifold Clustering and Embedding (SMCE) can adaptively select nearby points that lie in the same manifold based on sparse representation. However, there is no explicit project matrix in SMCE, and the unsupervised nature restricts its discriminating capability. Supervised Sparse Manifold Embedding (SSME) was proSparse Manifold Clustering and Embedding (SMCE) can adaptively select nearby points that lie in the same manifold based on sparse representation. However, there is no explicit project matrix in SMCE, and the unsupervised nature restricts its discriminating capability. Supervised Sparse Manifold Embedding (SSME) was proposed for dimensionality reduction of hyperspectral data. At first, the SSME method finds the sparse coefficients in affine subspace by solving a sparse optimization problem. It constructs the similarity weight matrix using the sparse coefficients, and naturally incorporates the label information into the weights. Then, it tries to extract discriminative features by increasing the compactness between homogeneous data in a low-dimensional embedding space. The experiments show that the SSME method not only inherits the merits of the sparsity property but also improves the severability of data points from different classes..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1228001 (2015)
The Object-based Method of Shadow Detection in High-resolution Remote Sensing Imagery
SHUAI Tao, ZHANG Hong-yan, and ZHANG Liang-pei
The shadow areas have the characters of lower brightness, higher saturation and greater hue value. Over-segmentation of the high resolution remote sensing image was operated, and the red, green and blue color image was transformed to the hue, intensity and saturation space. A shadow index was calculated using the hue, The shadow areas have the characters of lower brightness, higher saturation and greater hue value. Over-segmentation of the high resolution remote sensing image was operated, and the red, green and blue color image was transformed to the hue, intensity and saturation space. A shadow index was calculated using the hue, intensity and saturation, which could separate shadow from other classes. An object-oriented processing was performed on the shadow index results, which could keep the spatial geometry information of image. OSTU algorithm is used to choose a suitable threshold value. With the threshold value, the shadow detection results could be acquired by the histogram thresholding segmentation algorithm. Experimental results demonstrate that the proposed approach can be used to separate shadow from other classes effectively..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 44, Issue 12, 1228002 (2015)
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