Contents
2014
Volume: 34 Issue s1
52 Article(s)
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Research Article
A Fast Adaptive Interpolation Algorithm of High Spatial Resolution Remote Sensing Image
Xu Shuaijing, Zhang Libao, Li Zehua, and Li Aoxue
For the high spatial resolution remote sensing image, the size is vast, the object features are abundant and the edge information is complex. According to its characteristics, a fast adaptive interpolation algorithm applied to the high spatial resolution remote sensing image is proposed. The new algorithm classifies thFor the high spatial resolution remote sensing image, the size is vast, the object features are abundant and the edge information is complex. According to its characteristics, a fast adaptive interpolation algorithm applied to the high spatial resolution remote sensing image is proposed. The new algorithm classifies the interpolative dots according to the parity of the coordinate, and gets edges of the original image by applying the Canny operator. Every rectangular area comprised of four neighboring pixel is classified into five types in accordance with the edge characteristics, and the fast interpolation is finished for different types of the interpolative dots. The relationship among pixel of the original image and the assigned interpolation points are used to assign values to the rest dots. Experimental results show that the new algorithm can not only have a low computational complexity, but also accurately preserve edges and prevent blur. In addition, it can effectively enhance the low peak signal to noise ratio. The new algorithm has high practical value to researches on interpolation algorithm of the remote sensing image..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 110005 (2014)
[in Chinese]
Preliminary Study on the Seawater Scattering Properties in the Outside Estuary of the Yangtze River
Zhu Jianhua, Han Bing, Ye Huping, and Yang An′an
Variability of particulate scattering properties and its possible influencing factors are studied using the in-situ inherent optical properties (IOPs) data obtained during april 2012 in the outside estuary of the Yangtze River. Twelve stations are monitored, and the result shows that the average of particulate backscatVariability of particulate scattering properties and its possible influencing factors are studied using the in-situ inherent optical properties (IOPs) data obtained during april 2012 in the outside estuary of the Yangtze River. Twelve stations are monitored, and the result shows that the average of particulate backscattering coefficients and backscatter ratios at 488 nm at the surface, 5, 10, 20, 30 m depth are 0.0617, 0.0683, 0.0642, 0.0606, 0.1294 m-1 and 1.77%, 1.92%, 1.94%, 1.98%, 2.15%, respectively. The average of particle refractive index at the five layers is 1.14. Except one or two stations, it varies between 1.1 and 1.2. These show the domination of the inorganic mineral particles in this area, although the absorption peak around 676 nm implies a significant concentration of pigment particles in the water. In conclusion, subject to the abundant input of fresh water from the Yangtze River and the re-suspension of bottom particles, particulate scattering and backscattering dominate the IOPs and their variabilities. Also, non-organic mineral particles are the dominant constituents in seawater. Moreover, the variation of particulate scattering shows strong correlation with the depth..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 101001 (2014)
Propagation Characteristics of Beam Higher-Order Moments by Using Matrix Formulae
Li Xiaoqing, and Ji Xiaoling
The matrix formulae of beam higher-order moments through an optical system in atmospheric turbulence are derived by using the Wigner distribution function (WDF). It is shown that the fourth-order moment matrix depends on two turbulence parameters Tμν and μν, the third-order and the second-order moment matrixes depend oThe matrix formulae of beam higher-order moments through an optical system in atmospheric turbulence are derived by using the Wigner distribution function (WDF). It is shown that the fourth-order moment matrix depends on two turbulence parameters Tμν and μν, the third-order and the second-order moment matrixes depend on only Tμν, and the first-order moment matrix is independent of turbulence. The results obtained in this paper are general, for example, the matrix formulae of beam higher-order moments through Kolmogorov turbulence, non-Kolmogorov turbulence, optical system or free space can be given as special cases. The advantages of matrix formulation are that the expressions for higher-order moments are brief, and the physical meanings of higher-order moments are clear. The results obtained in this paper are of considerable theoretical and practical interest..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 101002 (2014)
Experiment and Analysis on Measurement of Isoplanatic Angle
Zong Fei, Qing Xiwen, Wu Min, Chang Jinyong, and Feng Shuanglian
Isoplanatic angle is one of important atmospheric turbulence parameters which has play a significant role in system design and compensation effect of adaptive optics. A apodized mask with triple concentric annuluses is introduced and applied to high precision measurement of isoplanatic angles. Principle and measurementIsoplanatic angle is one of important atmospheric turbulence parameters which has play a significant role in system design and compensation effect of adaptive optics. A apodized mask with triple concentric annuluses is introduced and applied to high precision measurement of isoplanatic angles. Principle and measurement technique are presented, and isoplanatic angle is measured at night in Xi′an. The conclusion of theoretical derivation shows that the apodized mask can modulate irradiance of star light received as a “5/3” power of height and improve measurement precision. The measurement results shows that isoplanatic angles in a range 5~10 μrad at night in Xi′an agree with that in the same latitude regions. The suggestions for improving experimental device are proposed..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 101003 (2014)
Effects on High-Precession Tracking on Active Illumination Laser
Yang Yuchuan, Guan Xiaowei, Tan Bitao, and Long Chao
Laser illumination is an effective technology for the imaging and tracking to the far dim targets in the air. Because of laser transmitting in the air, the spatial distribution of intensity on the target plane is non-uniform caused by atmospheric turbulence, and the laser wavefront generates aberration, which decreasesLaser illumination is an effective technology for the imaging and tracking to the far dim targets in the air. Because of laser transmitting in the air, the spatial distribution of intensity on the target plane is non-uniform caused by atmospheric turbulence, and the laser wavefront generates aberration, which decreases image resolution and tracking accuracy in optical system. A model of illumination laser propagation in atmosphere has been built. Under the condition of moderate turbulence, weak turbulence and multi-beams, numeric simulation for laser illumination to air targets has been carried out, and the affects of illumination light intensity and wavefront on remote target imaging are analyzed. The results show that illumination light intensity fluctuation variance below 0.5 and wavefront aberration standard error below 0.2 λ meet 1 μrad magnitude resolution capability..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 101004 (2014)
Validation for the Remote Sensing Reflectance of Geostationary Ocean Color Imager in Bohai Sea
Zhu Jianhua, Li Jun, Han Bin, Yang Anan, and Gao Fei
On the September 13, 2012 to September 15, Liaodong Bay of Bohai high turbidity water body remote sensing reflectance field observation is used to assess period geostationary ocean color imager (GOCI) remote sensing reflectance, and results show that the Rrs (λ) of GOCI spectral type with field observations is consisteOn the September 13, 2012 to September 15, Liaodong Bay of Bohai high turbidity water body remote sensing reflectance field observation is used to assess period geostationary ocean color imager (GOCI) remote sensing reflectance, and results show that the Rrs (λ) of GOCI spectral type with field observations is consistent with the overall low. 555 nm band consistency among the best, with an average relative percentage deviation (RPD) reaches 5%, and 865, 745 and 412 nm significantly undervalued, the RPD of 412 nm reaches about 60%. The root-mean-square error (RMSE) of 412 nm band is nearly 10 times the 865 nm band and band-based index showing trends. Greenwich wean time (GMT) 416 (local time 1216) contrast is better than other times of the observations. This evaluation results show that on the one hand GOCI turbid water body better observation of the effect, on the other hand there still need further improvement GOCI atmospheric correction algorithm..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 101005 (2014)
Adaptive Stochastic Parallel Gradient Descent Algorithm and Its Application in Coherent Beam Combining
Luo Cheng, Su Rongtao, Wang Xiaolin, and Zhou Pu
The fundamental theory for coherent beam combing (CBC) via using stochastic parallel gradient descent (SPGD) algorithm is introduced and an adaptive SPGD algorithm is proposed. The convergence rate is increased by adaptively controlling the perturbations and stages of the SPGD algorithm. The results show that for CBC oThe fundamental theory for coherent beam combing (CBC) via using stochastic parallel gradient descent (SPGD) algorithm is introduced and an adaptive SPGD algorithm is proposed. The convergence rate is increased by adaptively controlling the perturbations and stages of the SPGD algorithm. The results show that for CBC of laser arrays with 25 channels, 49 channels and 100 channels by using adaptive SPGD algorithm, the convergence rates are increased by 36.6%, 59.8% and 80.2%, respectively. This method has an advantage for CBC of laser arrays with large number of lasers..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 101006 (2014)
Detectors
Technology and Performance of Metal-Semiconductor-Metal AlGaN/GaN Heterostructure Ultraviolet Photodetector
Yang Lechen, Fu Kai, Shi Xueshun, Chen Kunfeng, Li Ligong, and Zhang Baoshun
AlGaN/GaN heterostructure metal-semiconductor-metal (MSM) structure ultraviolet (UV) photodetector with Ni/Au electrodes is fabricated. Opto-electrical characteristics and current-voltage characteristics of the detector are investigated. It is found that the detector has two spectral response ranges. The peak response AlGaN/GaN heterostructure metal-semiconductor-metal (MSM) structure ultraviolet (UV) photodetector with Ni/Au electrodes is fabricated. Opto-electrical characteristics and current-voltage characteristics of the detector are investigated. It is found that the detector has two spectral response ranges. The peak response is 0.717 A/W at 288 nm and 0.641 A/W at 366 nm. The quantum efficiency is 308% at 288 nm and 217% at 366 nm..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 104001 (2014)
Fiber Optics and Optical Communications
Research on High Speed Multichannel Fiber Optical Fabry-Perot Sensor Demodulation System
Li Jianning, Zhu Yong, Wang Ning, and Li Junshou
A multichannel fiber-optical Fabry-Perot (F-P) demodulation system based on non-scanning correlation demodulation using white light interfered F-P sensor is proposed. This system uses a Fizeau interferometer and a linear array CCD to achieve F-P demodulation. High speed demodulation is realized by means of enhancing opA multichannel fiber-optical Fabry-Perot (F-P) demodulation system based on non-scanning correlation demodulation using white light interfered F-P sensor is proposed. This system uses a Fizeau interferometer and a linear array CCD to achieve F-P demodulation. High speed demodulation is realized by means of enhancing optical energy utilization efficiency with symmetrical optical system and improving hardware system′s signal-to-ratio. The prototype of non-scanning correlation demodulation fiber-optical F-P demodulator is made and tested. The testing results show that the demodulation resolution of the prototype is 8 nm, the stability is 7.5 nm and the demodulation speed is up to 1.5 kHz. This method provides a feasible solution, which achieves high demodulation speed and expands fiber-optical F-P demodulator′s application fields..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 106001 (2014)
New Method for Measurement of Polarization States of Fiber Distributed Feedback Lasers
Zhang Zhenwei, Zhang Caixia, Shan Enmei, Zheng Wanfu, Liu Xiaohang, Xu Ben, Dong Xinyong, and Li Yi
A novel method for the measurement of the polarization states of fiber distributed feedback (DFB) laser is proposed, which is based on stimulated Brillouin scattering (SBS) amplification effect in optical fibers. Based on the interaction of the outputs of a tunable laser source (TLS) and a DFB laser, the absolute wavelA novel method for the measurement of the polarization states of fiber distributed feedback (DFB) laser is proposed, which is based on stimulated Brillouin scattering (SBS) amplification effect in optical fibers. Based on the interaction of the outputs of a tunable laser source (TLS) and a DFB laser, the absolute wavelengths of the double polarization states, the relative wavelength interval and respective light power of the laser are obtained. The influence of lateral pressure to the DFB laser is studied, and the single-polarization single-mode output is realized. Compared with the method using Fabry-Perot (FP) etalon, FP interferometer and heterodyning in previous studies, this method is easier to operate and can acquire more informations about the polarization states..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 106002 (2014)
Investigation of Astronomical Fiber Mode Converter
Zhu Xiaoliang, Sun Weimin, and Yan Qi
A special kind of astronomical fiber device which is called as optical fiber brush is introduced. Its fabricating technique and the supermode coupling characteristics are investigated. Due to the low dispersion of astronomical imaging, the supermode coupling charateristic of the optical fiber brush is studied. In orderA special kind of astronomical fiber device which is called as optical fiber brush is introduced. Its fabricating technique and the supermode coupling characteristics are investigated. Due to the low dispersion of astronomical imaging, the supermode coupling charateristic of the optical fiber brush is studied. In order to investigate and compare the divergence angle of different supermodes, near-field and far-field distributions of them are also calculated. Comparing with the far-field mode radius, it′s found that the in-phase supermode has the least divergence angle and the best beam quality. The research result can be helpful to investigate simillar fiber mode converters..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 106003 (2014)
Visible Light Communication System Based on Direct Sequence Spread Spectrum
Yuan Xueguang, Zhang Yang′an, Zhang Jinnan, and Zhang Minglun
A direct sequence spread spectrum scheme for visible light communication system is proposed. The spread spectrum scheme is based on the Shannon theorem in information theory. Theoretical analysis result demonstrates that spread spectrum technology can mitigate the effect of multipath and improve the security in visibleA direct sequence spread spectrum scheme for visible light communication system is proposed. The spread spectrum scheme is based on the Shannon theorem in information theory. Theoretical analysis result demonstrates that spread spectrum technology can mitigate the effect of multipath and improve the security in visible light communication system. The simulation results show that the performance of direct sequence spread spectrum based system is improved comparing with the directly detecting system without spread spectrum. Spread spectrum is a practical approach to improve the reliability of the visible light communication system..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 106004 (2014)
Experimental Study of Fiber-Optic Ultrasonic Wave Sensing Based on Self-Mixing Interference Effect
Wu Chunxu, Wang Lutang, Fang Nian, and Qin Haijuan
Aiming at the detection requirements for ultrasonic waves resulted from partial discharges in power transformers, a fiber-optic ultrasonic wave sensor system with a simple and novel structure utilizing the self-mixing interference effect in a semiconductor laser combined with Sagnac interferometric techniques is proposAiming at the detection requirements for ultrasonic waves resulted from partial discharges in power transformers, a fiber-optic ultrasonic wave sensor system with a simple and novel structure utilizing the self-mixing interference effect in a semiconductor laser combined with Sagnac interferometric techniques is proposed. Under the condition of weak external optical feedback, the partial discharges can be determined by measuring the changes of oscillating frequency of the laser diode induced by the disturbances of sensing fiber by discharge-induced ultrasonic waves with the Sagnac interferometer. The operation principles of the system are explored and experimental researches are carried out. The ultrasonic waves produced by various ways such as pencil broken, metal pin free falling and piezoelectric ceramics are detected. The sensing performances of the experimental system are tested. The discharge phenomena in a power system are simulated with high-voltage discharges occurring between two parallel copper wires, including the corona discharges and partial discharges. They are detected under different humidity levels and voltages. The satisfied results are obtained. All the experimental results show that the proposed sensor system has high sensitivities and good high frequency responses as well as a capacity to detect weak ultrasonic waves up to 300 kHz. It can be concluded that the proposed system can meet the requirements for partial discharge detection in the power industry..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 106005 (2014)
Novel Modulation Scheme of 6-PolSK for Atmospheric Laser Communication
Yuan Xueguang, Zhang Yang′an, Zhang Jinnan, and Zhang Minglun
A modulation scheme of 6-PolSK for atmospheric laser communication is proposed. Theoretical analysis result demonstrates that the states of polarization (SOPs) and degree of polarization (DOP) of light wave can be well maintained after long distance propagation in the atmospheric channel with different turbulence modelA modulation scheme of 6-PolSK for atmospheric laser communication is proposed. Theoretical analysis result demonstrates that the states of polarization (SOPs) and degree of polarization (DOP) of light wave can be well maintained after long distance propagation in the atmospheric channel with different turbulence models. Simulation results show that the transmission performance and the bandwidth efficiency are improved considerably. 6-PolSK modulation is an attractive approach to meet the criteria about data rate and bandwidth efficiency of the atmospheric laser communication system..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 106006 (2014)
Wideband and Low Group Velocity in a Novel Photonic Crystal Waveguide
Dong Xiaowei, and Quan Wei
A novel slow light photonic crystal waveguide is proposed by introducing two additional adjacent holes into the single line-defect structure. Influences of the boundary row shifts and the additional holes′ distance on the device performances are investigated in detail. Compared with the boundary row shifts method, a beA novel slow light photonic crystal waveguide is proposed by introducing two additional adjacent holes into the single line-defect structure. Influences of the boundary row shifts and the additional holes′ distance on the device performances are investigated in detail. Compared with the boundary row shifts method, a better slow light property can be obtained by modifying the distance of two additional adjacent holes. Numerical results demonstrate that the group velocity is reduced to 0.03c (c is the light velocity in vacuum) under nearly the same operational bandwidth..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 106007 (2014)
Demodulation of White-Light Interferometry Based on Variable Sampling Length Fourier Transform
Xie Jiehui, Wang Fuyin, Hu Zhengliang, and Hu Yongming
The Fourier transform (FT) method for demodulating the extrinsic Fabry-Perot interferometer (EFPI) possesses the advantage of high resolution and wide dynamic range for the absolute measurement in demodulating white-light EFPI. However, the dynamic range and the resolution of this method are limited by the nonlinear reThe Fourier transform (FT) method for demodulating the extrinsic Fabry-Perot interferometer (EFPI) possesses the advantage of high resolution and wide dynamic range for the absolute measurement in demodulating white-light EFPI. However, the dynamic range and the resolution of this method are limited by the nonlinear relationship with the scanning wavelength and the fence effect of FT, respectively. The cubic spline interpolation and a modified FT algorithm are used to reduce the influence of chirped spectrum and increase the resolution, respectively. The simulation and the experimental results show that the algorithm has seventy times enhancement of the resolution of demodulation..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 106009 (2014)
Preparation of Yb3+ Doped Microstructure Fiber and Amplification Experiment of Femtosecond Laser
Tian Yunyun, Zhou Guiyao, Zhang Wei, Xia Changming, Wang Chao, Cao Lei, Chen Yan, and Liu Jiantao
The Yb3+ doped microstructure fiber is prepared by the method of high temperature plasma non-chemical vapor deposition combined with the solution doping method. Its loss is 7.5 dB/m at the wavelength of 976 nm which indicates it has good absorption efficiency at this wavelength. In order to test its laser performance, The Yb3+ doped microstructure fiber is prepared by the method of high temperature plasma non-chemical vapor deposition combined with the solution doping method. Its loss is 7.5 dB/m at the wavelength of 976 nm which indicates it has good absorption efficiency at this wavelength. In order to test its laser performance, fluorescence properties are measured and a back-end pump laser amplifier system is constructed. Using an optimized 3 m length of the fiber and the seed femtosecond laser with 150 fs pulse width, 50 MHz repetition frequency and 1030 nm central wavelength, the femtosecond laser of 138 mW is successfully amplified to 605 mW, and the mode is in conformity with the Gaussian distribution. The results verify the feasibility of the doped fiber preparation method, make contributions to the exploration of new preparation methods of doped microstructure fiber and lay the foundations for high power Yb3+ doped femtosecond laser amplifier and high power lasers..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 106010 (2014)
Optimal Research of Resonance Characteristic of Adaptive Fiber-Optics Collimator
Liu Hongmei, Geng Chao, Luo Wen, Wang Caixia, and Li Xinyang
The adaptive fiber-optics collimator (AFOC) is a kind of passive fiber-optics device with the capability of fast and precise tip-tilt deviation control of collimated output. With the rapid extension of its application areas, the AFOC with greater resonance characteristic is needed. A method of using step-profile dampinThe adaptive fiber-optics collimator (AFOC) is a kind of passive fiber-optics device with the capability of fast and precise tip-tilt deviation control of collimated output. With the rapid extension of its application areas, the AFOC with greater resonance characteristic is needed. A method of using step-profile damping structure to improve the resonance characteristic of AFOC is experimentally studied, and the results reveal that the first-order resonance frequency increases with the reduction of the first-order resonance peak. On this basis, a way to enhance the available bandwidth of AFOC is studied theoretically and experimentally based on the biquad digital filter technique. Experimental results show that the first-order resonance peak of AFOC is suppressed efficiently and the usable operation bandwidth increases from about 1.3 kHz to 2.5 kHz..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 106011 (2014)
Image Processing
Study on the Underwater Optical image Clarity Enhancing
Li Qingwu, Shu Daiqun, Zhou Yan, Sheng Huixing, and Huo Guanying
Low contrast and color change are caused by scattering and attenuation of the light in the underwater environment. The method integrated dark channel prior and white balance for underwater color image enhancement is presented. According to the characteristics of underwater imaging, underwater optical imaging model is eLow contrast and color change are caused by scattering and attenuation of the light in the underwater environment. The method integrated dark channel prior and white balance for underwater color image enhancement is presented. According to the characteristics of underwater imaging, underwater optical imaging model is established. The optimized and improved dark channel prior algorithm is used for image deblurring, and then color correction on the restored image based on the white balance theory is performed. The quality of underwater color image is improved. The experiments show that the proposed method can effectively remove the blur caused by the scattering of light, enhances the visibility of underwater images and restores color balance of the underwater image. The clarity and color fidelity of underwater color images are improved significantly..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 110001 (2014)
Saliency Region Detection of Remote Sensing Image Based on Multi-Scale Frequency Analyses
Yang Xuye, Li Xuewei, and Zhang Libao
Frequency domain analysis can well detect the edge of the salient region in the remote sensing imagery detecting. But it may mistakenly regard the inner parts of the saliency region as the background. A new algorithm based on multi-scale fusion techniques of the image high frequency information is proposed. First, the Frequency domain analysis can well detect the edge of the salient region in the remote sensing imagery detecting. But it may mistakenly regard the inner parts of the saliency region as the background. A new algorithm based on multi-scale fusion techniques of the image high frequency information is proposed. First, the new algorithm creates several spatial scales of remote sensing images by using Gaussian pyramid. Then, for each scale, the new algorithm can get the high frequency information by the Fourier transform. Finally, the new algorithm gets the final saliency map by fusing the high frequency information on one scale. The new algorithm can not only well extract details of the salient region, but also effectively get rid of mistaken detection of the inner parts of the saliency region. Comparing with Itti model, the new algorithm has lower computation complexity..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 110002 (2014)
Earth Imaging Geometric Characteristics and Stagger Correction of Staggered Linear Array
Wang Yun, Sun Shengli, and Lin Changqing
Space camera uses the staggered linear array for earth imaging, notable stagger distortion is presented between the odd and even parts of the image data in along track direction, in order to ensure the geometric accuracy of the remote images, a stagger correction method is proposed. The earth imaging geometrical model Space camera uses the staggered linear array for earth imaging, notable stagger distortion is presented between the odd and even parts of the image data in along track direction, in order to ensure the geometric accuracy of the remote images, a stagger correction method is proposed. The earth imaging geometrical model of the space camera is established by utilizing coordinate transformation, and the reason that leads to stagger distortion is discussed. The earth imaging characteristics of the staggered linear array is analyzed. The stagger value in along track direction and along the direction of the linear array is calculated, and the influences on stagger value introduced by orbital displacement, attitude fluctuations, and terrain topography are analyzed based on Monto-Carlo method. A stagger correction method based on optical flow field is proposed according to the characteristics of the stagger distortion, the optical flow field is generated by the block matching of the odd and even parts of the image, and the image is corrected by the calculated optical flow field. The method is used for stagger correction of an infrared camera, remarkable result is reached, which verifies the validity of the stagger distortion analysis method and the stagger correction method..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 110003 (2014)
Imaging Systems
Autofocusing Research on Terahertz Gabor Inline Digital Holography
Li Qi, Hu Jiaqi, and Li Yunda
Terahertz (THz) digital holography is an important research aspect of terahertz imaging technology. The recording distance of terahertz digital holography is generally short because of the long wavelength and restriction of the detector. The exact measurement of the real recording distance is of great significance. AutTerahertz (THz) digital holography is an important research aspect of terahertz imaging technology. The recording distance of terahertz digital holography is generally short because of the long wavelength and restriction of the detector. The exact measurement of the real recording distance is of great significance. Autofocusing researches have been made on real 2.52 THz Gabor inline digital holograms based on five kinds of autofocusing criterion functions. The criterion precision is improved by cropping object in the reconstructed images. The experimental results show that the performance of normalized variance criterion function is the best. The results verify the feasibility of applying five kinds of autofocusing criterion functions to terahertz inline digital holography..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 111001 (2014)
Technology of Vibration Suppression Based on Multiple Integration for Staring Imaging System in Geostationary Orbit
Tao Xiaoping
Images captured by the staring imaging system in geostationary orbit usually emerge blur because of the satellite vibration in the exposure time. To eliminate the motion blur degradation, the paper proposes to capture multiple short-exposure images and fuse them on sub-pixel scale instead. Image sequences with differenImages captured by the staring imaging system in geostationary orbit usually emerge blur because of the satellite vibration in the exposure time. To eliminate the motion blur degradation, the paper proposes to capture multiple short-exposure images and fuse them on sub-pixel scale instead. Image sequences with different conditions are captured by a high-speed camera, cooperated with a vibration simulation system. The sub-pixel displacements between the different frames estimated by image registration algorithm are compared with the motion data measured by the linear encoder. Experimental results indicate that the algorithm precision is better than 0.1 pixel. Several sharpest short-exposure frames are chose for sub-pixel image fusion. Compared with the long-exposure image, the motion blur in the fusion image is weakened. It proves that the method of multiple integration and sub-pixel image fusion is powerful of vibration suppression for staring imaging system in geostationary orbit..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 111002 (2014)
Analysis of the Optical Performance of Collimation System in the Terahertz Scattering Measurement
She Jianyu, Li Qi, Zhao Yongpeng, and Chen Deying
In order to study the factors of collimation system in the terahertz scattering measurement, the collimation system in Terahertz scattering measurement system is modeled and simulated by the use of the optical design software Zemax. From the laser beam waist and divergence angle of emission laser these two aspects respIn order to study the factors of collimation system in the terahertz scattering measurement, the collimation system in Terahertz scattering measurement system is modeled and simulated by the use of the optical design software Zemax. From the laser beam waist and divergence angle of emission laser these two aspects respectively, in 118.83 μm terahertz emission sources, the effects of emission laser on collimation properties, width and divergence angle of collimated beam are studied, which provide theoretical supports in the scattering characteristics of the actual more accurate measurements..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 111003 (2014)
Vibration Performance Researching in the MEMS Galvanometer of an Imaging Lidar System
Qu Yang, Wang Chunhui, Pang Yajun, and Tang Tiantian
The micro electro mechanical system (MEMS) galvanometer of an imaging lidar system is analyzed, experiment measures the key elements of the vibration performance of MEMS: frequency and driving voltag. The results show that scanning in the frequency of 60~200 Hz and driving voltage belove 60 V can make wide angle scanniThe micro electro mechanical system (MEMS) galvanometer of an imaging lidar system is analyzed, experiment measures the key elements of the vibration performance of MEMS: frequency and driving voltag. The results show that scanning in the frequency of 60~200 Hz and driving voltage belove 60 V can make wide angle scanning and satisfy the demand of 64~256 point per second..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 111004 (2014)
Comparisons of Restoration Algorithm for Terahertz Confocal Scanning Image
Li Qi, and Yang Yongfa
In the terahertz confocal scanning imaging, the imaging quality is to be improved for the reason that terahertz laser can not output the beam constantly and that the signal collected is weak, and so on. The comparison among median filtering, block-matching and three dimensional (3D) filtering (BM3D), non-local means fiIn the terahertz confocal scanning imaging, the imaging quality is to be improved for the reason that terahertz laser can not output the beam constantly and that the signal collected is weak, and so on. The comparison among median filtering, block-matching and three dimensional (3D) filtering (BM3D), non-local means filtering (NLM) and median non-local means filtering (MNLM) is made after eliminating the background suppression resulting from laser shaking. The influence of the filtering parameters on the processed effect is studied. The results of image processing show that on the condition of applying definitive filter parameters to the investigation images, MNLM′s effect is better than that of NLM′s, and NLM′s effect is better than BM3D′s, while median filtering′s effect is the worst..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 111005 (2014)
Analysis of Imaging Quality of Space Camera Based on Thermally Induced Low Frequency Error
Dou Qiang, Li Jindong, Zhu Jun, Cao Qipeng, and Zhou Yu
A thermal/structural/optical integrated analysis method based on the changes of satellite attitude and orbit maneuver parameters is presented, which can reflect satellite camera transient heat flux and the temperature field of the low frequency dynamic process. Depending on the data of real-time temperature field, the A thermal/structural/optical integrated analysis method based on the changes of satellite attitude and orbit maneuver parameters is presented, which can reflect satellite camera transient heat flux and the temperature field of the low frequency dynamic process. Depending on the data of real-time temperature field, the real-time on-orbit thermal deformation is analyzed, and the camera optical axis direction of dynamic variation is calculated with thermal deformation data. The modulation transfer function (MTF) of the optical system and the dynamic optical axis direction changes are used to evaluate the image quality and the effect of the thermal control strategy. The analysis shows that attitude changes of high resolution remote sensing satellite cause external heat flux changes in its camera, which causes the temperature field changes of camera optical and mechanical structure. Thus, thermal stability of the camera suffers ordeal. Thermal stress caused by the temperature fluctuation and the temperature gradient makes the optical system to produce rigid body displacement and wave front aberration. As a result, the imaging quality is redused..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 111006 (2014)
Effects of Detector Parameters on Single Point Resolution of Terahertz On-Axis Digital Holography
Hu Jiaqi, Li Qi, and Yang Yongfa
Terahertz (THz) digital holographic imaging is one of the frontier research directions of terahertz imaging technology, the resolution is the key of this field. Most studies of digital holographic resolution are based on the classical resolution estimation, namely the two-point resolution, and rarely involve the singleTerahertz (THz) digital holographic imaging is one of the frontier research directions of terahertz imaging technology, the resolution is the key of this field. Most studies of digital holographic resolution are based on the classical resolution estimation, namely the two-point resolution, and rarely involve the single point resolution. Within an inverse problem framework, by comparing and analyzing the results of the single point resolution of terahertz on-axis digital holography in different detector parameters, the change in the resolution of each point on the object plane and the spatial distribution of single point resolution are given intuitively with the change in duty cycle, pixel number and other detector parameters. The results are of great significance to the optimization of detector parameters in practice and evaluating the improvement of the THz digital holographic resolution..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 111007 (2014)
Instrumentation, Measurement and Metrology
Lock-Imaging Technology to Detect Defects Fiber Reinforced Plastics Research
Jiang Yulong, Feng Lichun, Huang Xinping, and Zhang Cunlin
Infrared (IR) thermal wave inspection is a merging technology in nondestructive evaluation. Different from conventional passive infrared inspection, infrared thermal wave inspection work with a sample under transient or alternating temperature field. The surface temperature is recorded by a infrared camera, and the datInfrared (IR) thermal wave inspection is a merging technology in nondestructive evaluation. Different from conventional passive infrared inspection, infrared thermal wave inspection work with a sample under transient or alternating temperature field. The surface temperature is recorded by a infrared camera, and the data collected are processed according to the type of the temperature field and correspond physical model. Using lock-in thermography to test fiber reinforced plastics (FRP) material by SC3000 IR camera, and calculated by the fast Fourier transform (FFT) algorithm. Results show that the phase diagram effect is better than that of amplitude diagram, and different loading frequencies have different experimental results..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 112001 (2014)
Study on the Surface Shape Measurement of Planar Element Based on Slope Sensor Method
E Kewei, Li Dahai, Li Mengyang, Zhao Jiwen, Li Shuiyan, Zhang Chong, Dai Zhenqiang, and Wang Qionghua
Measurement of planar element using slope sensor method is based on the geometry of the fringe reflection and phase measuring deflectometry method which can be used to measure aspherical shapes and transmission optical element rapidly, simply and accurately. It can be called deflectometry or Hartmann test system in revMeasurement of planar element using slope sensor method is based on the geometry of the fringe reflection and phase measuring deflectometry method which can be used to measure aspherical shapes and transmission optical element rapidly, simply and accurately. It can be called deflectometry or Hartmann test system in reverse. We go through the derivation of measurement equation of planar element slope and wavefront reconstruction algorithm. By using an LCD screen with programmable fringe as illumination source, phase shifting method of four step is used to recognize display pixel coordinates, and a camera with small aperture images the surface under test. We apply this system to the measurement of acrylic plastic plate surface under the condition of and heating. The slope data can be obtained after operating these pictures by computer, and we use orthonormal vector polynomials fitting in a square area to calculate the surface shape of mirror under test, then analyze the surface information. And we use this system to test the slope change of acrylic plastic plate surface under the condition of stressing, and compare with the result of the laser-reflection method. The results show that the test system has a large dynamic range and is simple, rapid, non-contacting, and high-precision. It can supply a new method to test the planar surface shape and the dynamic changes of the object surface shape in practical production and application..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 112004 (2014)
Investigation on the Method of Suppress Noise in the Laser-EMAT Testing Based on Wavelet Threshold Technology
Cui Lei, Zhao Yang, Zhao Peng, Sun Jichang, and Jia Zhongqing
This work introduces the wavelet filter technique based on the soft threshold algorithm. The proposed method is applicable to the noise suppression during the detection process of the laser electromagnetic acoustic transducer (EMAT) technique. Experiments have been carried out on the 6016 aluminum plate, and the ultrasThis work introduces the wavelet filter technique based on the soft threshold algorithm. The proposed method is applicable to the noise suppression during the detection process of the laser electromagnetic acoustic transducer (EMAT) technique. Experiments have been carried out on the 6016 aluminum plate, and the ultrasonic signal of surface defect has been processed by wavelet filter designed by Matlab. The results show that the technique has good prospects in the engineering applications of laser-EMAT testing..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 112006 (2014)
Development of Precision One-Dimensional Adjustment Worktable Based on Aerostatic Bearing Technology
Hou Maosheng, Ji Lin, Liu Entao, Tian Yanrong, Ma Fei, and Zhao Weiqian
To achieve the high-precision one-dimensional adjustment of large surface under test in optical and mechanical measurements, a novel worktable based on the aerostatic bearing technology is developed. In the worktable, pitch or tilting motion is achieved by a cambered surface of aerostatic bearing and micro-displacementTo achieve the high-precision one-dimensional adjustment of large surface under test in optical and mechanical measurements, a novel worktable based on the aerostatic bearing technology is developed. In the worktable, pitch or tilting motion is achieved by a cambered surface of aerostatic bearing and micro-displacement actuators, and the relationship between the angle of one-dimensional adjustment and the displacement of actuators is analyzed. Furthermore, by using an electronic autocollimator, the resolution of one-dimensional adjustment worktable is measured. Errors of the one-dimensional adjustment system are analyzed and the performance evaluation of the system is given. The experimental results show that the worktable has a pitch or tilting adjustment resolution of 1.2″, adjustment range of ±1° and good stability with 50 kg load. The developed one-dimensional adjustment worktable can satisfy the requirements of higher precision, high resolution, large adjustment range, frictionless, high load stiffness, stabilization and small driving force..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 112007 (2014)
Two-Axis Turntable Calibration in Dot Structured Light Measurement System
Guan Banglei, Zhou Langming, Yang Xia, and Zhang Xiaohu
A new calibration method using monocular vision is proposed to calibrate the dot structured light measurement system. Let the laser rangefinder circle around the rotation axis and use two planes to intercept laser beam respectively in order to form the laser spot. Three-dimensional coordinates of the laser spot is obtaA new calibration method using monocular vision is proposed to calibrate the dot structured light measurement system. Let the laser rangefinder circle around the rotation axis and use two planes to intercept laser beam respectively in order to form the laser spot. Three-dimensional coordinates of the laser spot is obtained by monocular vision, the virtual output light spot of laser rangefinder is got by calculating the difference of the two laser spots. Direction vector of the rotation axis is fitted and point coordinate in the rotation axis is fixed. The use of virtual output light spot in the calibration improves the accuracy of rotation axis, so the rotation axis at any position can be calculated easily. The three-dimensional coordinates of target can be calculated by dot structured light measurement system though accurately calibrating the two axes of the turntable. The experiments show that the measuring precision of the system is within 0.5 mm at present, this calibration method is simple, reliable and can be used in other measuring system with a turntable..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 112008 (2014)
Transmittance Spectra Measurement and Optical Parameters Inversion of Liquid Hydrocarbon Fuel
Li Dong, Qi Hanbing, and Wu Guozhong
A novel inversion method of optical constants of semitransparent liquid hydrocarbon fuel is developed based on inversion calculation of spectral transmittance radio of optical cell filled with glass-liquid fuel-glass configuration, and validated by measuring the optical constants of water. The measurements of transmittA novel inversion method of optical constants of semitransparent liquid hydrocarbon fuel is developed based on inversion calculation of spectral transmittance radio of optical cell filled with glass-liquid fuel-glass configuration, and validated by measuring the optical constants of water. The measurements of transmittance spectrogram of optical cell filled with ethanol in the infrared wavelength of 2~15 μm at normal incidence are investigated by Bruke V70 FTIR spectrometer. The optical constants and thermal radiative physcial parameters of ethanol are achieved. The calculation precision of the novel method (IDTM model) is similar with MCDTM model, which is higher than SODTM and SDTM models. The transmittance capability of ethanol in the infrared wavelength of 2~15 μm is weak, and there are four absorption peaks, whose wavelengths are, respectively, 3.57 μm, 6.88~7.88 μm, 9.12~9.74 μm and 11.37 μm. The spectral selectivities of optical constants and thermal radiative physcial parameters of ethanol are stronger, whose values are urgently varied with different wavelengths..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 112009 (2014)
Key Techniques in Large-Aperture Phase-Shifting Interferometer Via PZT
Wu Xuhua, and Chen Lei
The key techniques of large-aperture phase-shifting interferometer via PZT are discussed, includings supporting scheme for large-aperture reference mirror, absolute test of large-aperture flat, on-line calibration of piezoelectric (PZT), test of dynamic phase and large-aperture collimated beam wavefront. Theoretical siThe key techniques of large-aperture phase-shifting interferometer via PZT are discussed, includings supporting scheme for large-aperture reference mirror, absolute test of large-aperture flat, on-line calibration of piezoelectric (PZT), test of dynamic phase and large-aperture collimated beam wavefront. Theoretical simulation and experimental measurement are done for developing larger-aperture phase-shifting interferometers..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 112011 (2014)
Lasers and Laser Optics
Investigation of Diode Pumped Passively Q-Switched [100]-and [111]-Cut Nd:YAG Laser
Sun Zhe, Cheng Qiutong, Jiang Menghua, Hui Yongling, Lei Hong, and Li Qiang
Thermal depolarization caused by birefringence is a major factor that limits the output power of linearly polarized Nd:YAG laser. Compared with conventional [111]- cut Nd:YAG rod, the thermal depolarization depends on the polarization direction for the [100]- cut Nd:YAG rod. The linearly polarized output power can be iThermal depolarization caused by birefringence is a major factor that limits the output power of linearly polarized Nd:YAG laser. Compared with conventional [111]- cut Nd:YAG rod, the thermal depolarization depends on the polarization direction for the [100]- cut Nd:YAG rod. The linearly polarized output power can be improved by suitable modification of the polarization direction of oscillate laser. The [111]- and [100]- cut Nd:YAG rods are used as the gain medium and the Cr4+:YAG crystal is used as the saturable absorber for passively Q-switched laser. The experiment demonstrates that in comparison with conventional [111]- cut Nd:YAG rod, highly stabled output with high extinction is achieved by using the [100]- cut Nd:YAG rod as the laser crystal. The extinction ratio is 5001 and polarized output stability is higher than 96.5%..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 114001 (2014)
Microstrucrures on the Surface of Si Induced by Femtosecond Laser
Wang Jixiang, Ran Lingling, Kong Degui, Gao Yang, Li Yanchao, Wu Wenzhi, Gao Yachen, and Chang Qing
By using femtosecond laser direct writing platform, the interaction between femtosecond and semiconductor silicon material are studied. The formation of microstructure on silicon under fixed dot irradiation and scan with femtosecond laser pulse at different laser power and pulses is described. Scanning electron microscBy using femtosecond laser direct writing platform, the interaction between femtosecond and semiconductor silicon material are studied. The formation of microstructure on silicon under fixed dot irradiation and scan with femtosecond laser pulse at different laser power and pulses is described. Scanning electron microscopy is used for observing the morphologies of the surface microstructure. It is experimentally demonstrated that the period and morphology of fabricated microstructures is effected by the laser power and pulse number. The orientation of the period stripe is effected by the polarization direction of the incident femtosecond laser. We can control the period stripe orientation by adjusting the polarization direction of the incident laser. Large area of microstructures can be induced on the surface of material by scanning. According to the experimental results, the effect of pulse number on period is analysed . The results provide a reference to the silicon surface microstructures processing..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 114002 (2014)
Study of Stimulated Brilliouin Scattering in the N-Hexane with Radially Polarization
Xiong Mengsu, Chen Xudong, and Pu Jixiong
The experiment uses a 532 nm high power laser as the light source, and the beam passes through the spirally varying retarder (SVR) to generate a polarized beam. A novel Brilliouin scattering is found by the stimulation of a high power radially polarization laser in the n-hexane. The resultant of Brilliouin scattering iThe experiment uses a 532 nm high power laser as the light source, and the beam passes through the spirally varying retarder (SVR) to generate a polarized beam. A novel Brilliouin scattering is found by the stimulation of a high power radially polarization laser in the n-hexane. The resultant of Brilliouin scattering is in radial polarized distribution when it is stimulated by the high power radially polarization laser. This phenomenon reveals the reservation of the same characteristics of radially polarization beam in the Brilliouin scattering experiment..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 114003 (2014)
Experimental Investigation on Power Stabilization of Chemical Oxygen Iodine Laser
Zhang Zheng, Ren Weiyan, and Guan Xiaowei
The modeling of chemical oxygen iodine laser power using a simplified saturation model is established. The main factors influencing the power of chemical oxygen iodine laser have been studied theoretically. According to the testing parameter of chemical oxygen iodine laser, the power stability caused by chlorine and ioThe modeling of chemical oxygen iodine laser power using a simplified saturation model is established. The main factors influencing the power of chemical oxygen iodine laser have been studied theoretically. According to the testing parameter of chemical oxygen iodine laser, the power stability caused by chlorine and iodine pressure has been analyzed. It is found that the root mean square (RMS) of chlorine and iodine venturitube pressure becomes small as the laser time increasing between 1 and 6 seconds, at the same time, the more RMS of chlorine, iodine venturitube pressure, the more RMS of chemical oxygen iodine laser power. Chemical oxygen iodine laser power stabilization increases by improving the pressure stabilization of chlorine and iodine venturitube..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 114004 (2014)
High Efficiency and High Beam Quality Diode Laser Array by Spectral Beam Combination
Zhu Zhanda, Gou Long, Jiang Menghua, Hui Yongling, Lei Hong, and Li Qiang
Improvement is made in the traditional spectral beam combining structure by adding beam shaping element, namely BTS. BTS is used to rotate the beam from the emitter in semiconductor laser array. The slow axis light distribution of each emitter becomes vertical distribution. The fast axis light distribution becomes horiImprovement is made in the traditional spectral beam combining structure by adding beam shaping element, namely BTS. BTS is used to rotate the beam from the emitter in semiconductor laser array. The slow axis light distribution of each emitter becomes vertical distribution. The fast axis light distribution becomes horizontal distribution. Spectral beam combination is conducted by external cavity after beam shaping in horizontal direction. The effect of smile is reduced. As a result, the overall output beam quality and conversion efficiency is improved very much. A standard semiconductor laser array is used in this experiment. Output power of 70.01 W, electro-optic conversion efficiency of 52.8% and spectral beam combining efficiency of 92.2% are achieved. The spectral line-width is 7.7 nm. M2 of 1.28 (0.4 mm·mrad) in horizontal and 11.2 (3.5 mm·mrad) in vertical are obtained. The beam quality of the output is close to that of a single emitter of the array in both directions..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 114008 (2014)
Experimental Research of R600a Heat Transfer Performance in a Closed Spray Cooling System
Xu Hongbo, Qian Chunchao, Shao Shuangquan, Tian Changqing, and Si Chunqiang
To improve the heat dissipation performance of the high power solid state laser, a spray cooling system is designed based on the refrigeration cycle, with R600a as the coolant. The heat transfer performance of the closed spray cooling system is studied by experiment. The results show that the heat source surface temperTo improve the heat dissipation performance of the high power solid state laser, a spray cooling system is designed based on the refrigeration cycle, with R600a as the coolant. The heat transfer performance of the closed spray cooling system is studied by experiment. The results show that the heat source surface temperature is affected by the nozzle inlet pressure and spray chamber evaporation pressure. And it is more effective to reduce the surface temperature by reducing the spray chamber evaporation pressure. For example, the decrease of 50 kPa evaporation pressure can result in the reduction of 8 ℃ of the surface temperature. The nozzle inlet pressure and spray chamber evaporation pressure also have a combined effect on the heat transfer coefficient. It is found that the heat transfer coefficient is up to 35000 W/(m2·℃) in the experiment. In addition, the surface temperature standard deviation is mainly affected by the nozzle inlet pressure, and it is hardly affected by the increasing of pray chamber evaporation pressure..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 114010 (2014)
Technologic Investigation of Laser Micro-Drilling on the Thin Ceramic Plate
Xiao Lei, Zhao Jiantao, Yan Zhenfeng, and Yao Yong
The laser precision micromachining processes on the thin ceramic plate are investigated. By taking pulse laser drilling as well as laser cutting technology, this work aims at improving the heat affected zone of laser processing as well as the conicity of microhole and increasing laser processing efficiency to satisfy tThe laser precision micromachining processes on the thin ceramic plate are investigated. By taking pulse laser drilling as well as laser cutting technology, this work aims at improving the heat affected zone of laser processing as well as the conicity of microhole and increasing laser processing efficiency to satisfy the industrial requirement. The laser process parameters including laser output power, duty cycle, repeated frequency, the offset of focus spot, the type of assistant gas and gas pressure are optimized in the experiments. The results show that the microholes with diameter of 80~200 μm are obtained by using CO2 laser drilling on ceramic plate and its efficiency up to 18 hole/s; the heat affected zone has also been significantly improved. The conicity controllable microholes are achieved by single pulse drilling technology with fiber laser and its efficiency achieves 300 hole/s. The stable laser precision micromachining on the ceramics for the straight microholes with diameter of 100 μm is also obtained by laser cutting technology using fiber laser and its efficiency achieves 6~8 hole/s..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 114012 (2014)
Nonlinear Optics
Design of Angular-Independent Solc-Type Electro-Optical Filter
Zheng Guoliang, Xu Shixiang, Ouyang Zhengbiao, and He Wei
An angular-independent Solc-type electro-optical filter based on two-dimensional (2D) angularly periodically poled LiNbO3 is presented. We find that the 2D angularly poled LiNbO3 can provide invariable radial reciprocal vectors which can be used in designing angular-independent Solc-type electro-optical filter. The stuAn angular-independent Solc-type electro-optical filter based on two-dimensional (2D) angularly periodically poled LiNbO3 is presented. We find that the 2D angularly poled LiNbO3 can provide invariable radial reciprocal vectors which can be used in designing angular-independent Solc-type electro-optical filter. The study demonstrates that the Solc-type filter based on 2D angularly poled LiNbO3 can keep its central passing wavelength unchanged even though the incident light deviate from the normal incidence. The angular-independent Solc-type electro-optical filter can find its application in multi-angle, multi-beam filtering..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 119002 (2014)
Continuous Splitting of Dissipative Optical Solitons Based on Complex Ginzburg-Landau Equation with Cubic-Quintic Nonlinearity
Liu Bin, Liu Yunfeng, and Li Shujing
The novel nonlinear dynamics of dissipative optical solitons supported by introducing a V-shaped potential of antiwaveguiding structures are reported based on the two dimensional (2D) complex Ginzburg-Landau (CGL) equation with cubic-quintic nonlinearity. If the potentials are strong enough, they give rise to continuouThe novel nonlinear dynamics of dissipative optical solitons supported by introducing a V-shaped potential of antiwaveguiding structures are reported based on the two dimensional (2D) complex Ginzburg-Landau (CGL) equation with cubic-quintic nonlinearity. If the potentials are strong enough, they give rise to continuous splitting of expanding solitons from a cental soliton. The rate of splitting increases with the growth of potential intensity. For a weak potential, the stretch of the cental soliton into ellipse shape is observed instead. For a too strong potential, the central soliton dissipates. In addition, the influence of effective diffusion, gain and loss coefficient on the dynamic regimes is studied. Sufficient energy gain is necessary to maintain continuous splitting of the center soliton..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 119003 (2014)
Optical Design and Fabrication
Optical Manufacturing of F Number of 0.42 Large-Deviation Off-Axis Aspheric Mirror
Li Ruigang
Aspherical components have been more and more widely used in optical systems. In order to enhance the ability of light collecting for the optical system, highly steep aspheres are often used. However, manufacturing of highly steep aspheres is now one of the hard work in optical engineering field. Through a manufacturinAspherical components have been more and more widely used in optical systems. In order to enhance the ability of light collecting for the optical system, highly steep aspheres are often used. However, manufacturing of highly steep aspheres is now one of the hard work in optical engineering field. Through a manufacturing case of F number of 0.42 off-axis asphere with large asphericity, some researching progresses are introduced. The first is the milling technology for off-axis asphere, comparing with the traditional milling technology of the best fitting sphere (BFS), the remaining asperical error is decreased greatly, and the following grinding cycle is shortened about 2/3; while decreasing the sag difference of the asphere by coordinate transforming of the equation, the difficulty of manufacturing is greatly reduced. Meanwhile, by making the small tool running along the asphere′s normal, we can ensure the removal function′s symmetry, and the solving procedure of the tool′s position and coordinate′s compensation is given in detail. The example shows that the final asphere precision [root-mean-square (RMS)] attains to 0.039λ (λ is 632.8 nm)..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 122001 (2014)
An Alignment Method of Off-Axis Aspheric Mirror
Han Juan, Duan Jiayou, Chen Jianjun, and Wu Mengyuan
In order to realize the accurate position of an off-axis aspheric surface in optical alignment, it is necessary to strictly control the six degrees of freedom, especially the two degrees of freedom that affect lateral displacement and tilts angle. But it′s very difficult to obtain the above two accurate values using geIn order to realize the accurate position of an off-axis aspheric surface in optical alignment, it is necessary to strictly control the six degrees of freedom, especially the two degrees of freedom that affect lateral displacement and tilts angle. But it′s very difficult to obtain the above two accurate values using general off-axis aspheric surface measurement technique, so it′s same difficult to realize its precise alignment. The article introduces a new method that applying the close relationship between the center image of radius of curvature and the optical axis of the self-regulating instrument, and by using the precise measurement, the purpose of measuring lateral displacement and tilts angle is achieved. Experiments show that the error of lateral displacement is less than 0.05 mm, the error of tilts angle is less than 10″, and the wave aberration root mean square is equal to 0.02λ (λ=632.8 nm). It can obtain the perfect image and realize the precise alignment of the off-axis aspheric mirror by using this method..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 122002 (2014)
Optical System Design of the Four Lenses High Definition Video Telephoto Objective
Gao Xingyu, Yu Daoyin, Long Yue, and Xiao Zexin
In order to realize remote detection of surface cracks of cable-stayed bridges, a four lenses high definition video telephoto objective is designed. The image sensor is a complementary metal-oxide-semiconductor (CMOS) camera with a cell size of 1.4 μm×1.4 μm, target surface size of 1/2.3″ and a definition of 14 meIn order to realize remote detection of surface cracks of cable-stayed bridges, a four lenses high definition video telephoto objective is designed. The image sensor is a complementary metal-oxide-semiconductor (CMOS) camera with a cell size of 1.4 μm×1.4 μm, target surface size of 1/2.3″ and a definition of 14 megapixel. To match the design requirement of the camera, the definition on the image surface of the telephoto objective is designed as 357 lp/mm, with a focal length of 320 mm, the relative aperture of 1/6.95, and the angle of view field of 1.379°. On the object side, the telephoto objective has the capability to distinguish a line with width of 2 mm at a distance of 228 m, which satisfies the distance and the definition requirement for the cable detection of normal cable-stayed bridges..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 122004 (2014)
Physical Optics
Focus Shaping of Radial Polarized Beam Based on Pupil Filter
Zhu Huafeng, Wang Tianyang, Liu Pei, Fu Jianbo, Li Dailin, Wang Ning, and Wang Xiumin
The optical intensity distribution in the focal volume plays an important role on the performance for many optical systems. Effective manipulation of focused optical intensity distribution can be obtained by using a pupil filter composed by zonal optical diffractive element and zonal double half-wave plate which can moThe optical intensity distribution in the focal volume plays an important role on the performance for many optical systems. Effective manipulation of focused optical intensity distribution can be obtained by using a pupil filter composed by zonal optical diffractive element and zonal double half-wave plate which can modulate both the phase and the direction of polarization of incident radially polarized beam zone by zone, and turn radially polarized beam into zonal sylindrically polarized beam. Numerical simulations of Matlab show that different intensity distributions can be obtained in the focal volume. Using the method, besides the existing doughnut intensity distribution and flattop focal spot in focal plane, the flattop doughnut intensity in the focal plane with hollow three-dimension (3D) pattern is obtained. This result can find potential use in fields such as particle manipulation and caption, laser micromachining, etc..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 126001 (2014)
Influence of Astigmatism on Periodic Bottle Beam
Li Dong, Wu Fengtie, Li Pan, and Xie Xiaoxia
Periodic bottle beams can be generated by a line focusing Bessel beam illuminated on an axicon, the influence of astigmatism introduced by elliptical manufacture error and oblique illumination on the bottle beam generated by line focusing Bessel beam using axion is analyzed in terms of Fresnel-Kirchhoff diffractive thePeriodic bottle beams can be generated by a line focusing Bessel beam illuminated on an axicon, the influence of astigmatism introduced by elliptical manufacture error and oblique illumination on the bottle beam generated by line focusing Bessel beam using axion is analyzed in terms of Fresnel-Kirchhoff diffractive theory. The influence of astigmatism on the bottle beam is not big and the bottle beam still keeps its periodicity and ring closed characteristic, as long as the astigmatism is limited in a small range. The larger the base angle or the refractive index of the axicon is, the smaller the range is, and the more susceptible to the astigmatism introduced by the elliptical manufacture error and oblique illumination the bottle beam is. The result may serve as a guideline in the application of the periodic bottle beam..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 126002 (2014)
Spectroscopy
Determination of Serum Triglyceride Content by Fourier Near Infrared Spectroscopy and Partial Least Squares
Dong Haisheng, Zhang Lifen, Zhong Yue, Huang Jianying, and Chen Bin
Taking the whole blood obtained from daily clinical inspection as experimental materials, triglyceride concentration of serum is determined by traditional clinical method: glycerol phosphate oxidase-peroxidase-4-amino antipyrine-phenol method. Near infrared spectroscopy of all serum samples are collected at the same tiTaking the whole blood obtained from daily clinical inspection as experimental materials, triglyceride concentration of serum is determined by traditional clinical method: glycerol phosphate oxidase-peroxidase-4-amino antipyrine-phenol method. Near infrared spectroscopy of all serum samples are collected at the same time, with the range between 12500~4000 cm-1. A quantitative model of serum triglyceride concentration by near infrared spectroscopy is established by combining with partial least squares (PLS) method. Experimental results show that the proper variable range is 10796.2~8246.6 cm-1, and with the multiplicative scatter correction as spectrum pretreatment method, the quantitative PLS calibration model for serum triglyceride is established. The correlation coefficient R2=0.9454, cross-validation calibration standard deviation (RMSECV) is 0.146 for the calibration set; the predicted standard deviation (RMSEP) is 0.151, and correlation coefficient R2=0.9068 for the test set. The results show that, by the application of near infrared spectroscopy combined with partial least squares method, the serum triglyceride quantitative model is successfully established with high accuracy and stability, which can be used for non-destructive testing of triglyceride content in the unknown serum samples..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 130001 (2014)
Cell Constant Calibration of Photoacoustic System Based on A-Band Absorption Spectrum of Oxygen in the Air
Zhang Jianfeng, Chen Zhemin, Qiu Yue, and Pan Sunqiang
Photoacoustic spectroscopy is a kind of high sensitive detection method. Cell constant is an important parameter of photoacoustic detection system, which directly measurements the system′s ability of converting light energy into sound energy. So the calibration of the cell constant is an important job for photoacousticPhotoacoustic spectroscopy is a kind of high sensitive detection method. Cell constant is an important parameter of photoacoustic detection system, which directly measurements the system′s ability of converting light energy into sound energy. So the calibration of the cell constant is an important job for photoacoustic detection system′s metrology. Oxygen in the air is used to calibrate the cell constant. For a first order resonant cell, of which the length is 100 mm, and the diameter is 6 mm, the result of the calibration is 2330.8 Pa·cm·W-1, and the repeatability is 0.67%. Compared to the standard gas calibration result, the relative error is 0.54%. Experiments prove that it′s feasible to calibrate the cell constant online using oxygen in the air..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 130004 (2014)
Ultrafast Optics
Design of Linearly Chirped-Fiber-Bragg-Grating for Ultrashort Optical Pulse Shaping and Coding
Dong Xiaowei, Quan Wei, and Xie Yuan
A simplified signal-transform technique is utilized to map the output pulse temporal waveform into the spectral response of the shaper or coder. By designing the apodization profile of linearly chirped-fiber-Bragg-grating, a transform-limit Gaussian ultrashort optical pulse is shaped into a rectangular or triangular teA simplified signal-transform technique is utilized to map the output pulse temporal waveform into the spectral response of the shaper or coder. By designing the apodization profile of linearly chirped-fiber-Bragg-grating, a transform-limit Gaussian ultrashort optical pulse is shaped into a rectangular or triangular temporal output waveform. In addition, in order to demonstrate the feasibility for coding a train of optical pulses, non-return-zero(NRZ) or return-zero (RZ) pulse with 1011 codes are generated..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 34, Issue s1, 132001 (2014)
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