Contents
2015
Volume: 35 Issue 1
52 Article(s)
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Atmospheric Optics and Oceanic Optics
Retrieval of Aerosol Optical Thickness with MODIS Data over Hangzhou
Fan Jiao, Guo Baofeng, and He Hongchang
Because the aerosol type is very important in the inversion of optical thickness, it can greatly improve the inversion precision by using the most accurate aerosol type of the inversion area. Combined with the moderate resolution imaging spectroradiometer (MODIS) data, a mathematic model for solving the aerosol concentBecause the aerosol type is very important in the inversion of optical thickness, it can greatly improve the inversion precision by using the most accurate aerosol type of the inversion area. Combined with the moderate resolution imaging spectroradiometer (MODIS) data, a mathematic model for solving the aerosol concentration ratio in Hangzhou area is proposed. By using the aerosol types of this mathematical model, the aerosol optical thickness can be obtained based on the 6S atmospheric model combined with the improved dense dark vegetation. The aerosol observation results are compared with aerosol values detected by AERONET sun photometer, which show that the inversion error absolute value is within 20% . The Hangzhou area atmospheric aerosol optical standard type 6S atmospheric model is given and the thicknesses of the inversion are compared with the inversion values using custom aerosol. The results show that the absolute value of retrieval relative errors of optical thicknesses by using aerosol types of custom value is 3% lower than that by using standard aerosol type value..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 101001 (2015)
Atomic and Molecular Physics
Dynamic Model on Light Induced Drift of Lithium Atom Using Chaotic Field Approximation
Chai Junjie, Chen Risheng, and Xu Wenqiang
According to physical process of light induced drift (LID) and hyperfine structure of lithium absorbing spectrum, the Boltzmann collision equation of gas diffusion and density matrix equation of semiclassical theory are combined to gain the dynamic simulation model of LID, in which, the delay time approximation and chaAccording to physical process of light induced drift (LID) and hyperfine structure of lithium absorbing spectrum, the Boltzmann collision equation of gas diffusion and density matrix equation of semiclassical theory are combined to gain the dynamic simulation model of LID, in which, the delay time approximation and chaotic field model are used, and hyperfine structure and redistribution of excited state are taken into account. Using the statistic method of laser line width in LID, the differential equations of distribution on base and excited states of lithium atom with different velocities is proposed with chaotic field approximation..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 102001 (2015)
Calculation of Vibronic and Rotational Spectrum in the Electric Ground and Excited State of Magnesium Fluoride Molecule
Fang Yinfei, Xu Liang, Dai Dapeng, Li Xingjia, Du Xiangli, Yin Yanning, Zhang Hui, Xia Yong, and YinJianping
Laser cooling of molecule is one of the most important progresses on the generation of cold molecules in experiments. To find a suitable candidate for laser cooling experiment, the molecular structure parameters and spectral data must be understood. These parameters are important basis of choosing molecules. The detailLaser cooling of molecule is one of the most important progresses on the generation of cold molecules in experiments. To find a suitable candidate for laser cooling experiment, the molecular structure parameters and spectral data must be understood. These parameters are important basis of choosing molecules. The detailed calculations of vibronic structure and rotational hyperfine structure of the molecular X and A states are carried out. Considering the parameters of nuclear spins, excited lifetime, dark state,transition levels, and so on, a new suitable molecule (magnesium fluoride) for laser cooling is proposed, and the appropriate transition is used to form the quasi- closed energy level system for laser cooling. These parameters provide theory basis for the experimental measurement of spectral data, and lay a foundation for further laser cooling experiments..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 102002 (2015)
Diffraction and Gratings
Electrically Controlled Grating Based on PPLN
Zhang Xinxin, and She Weilong
An electrically controlled broadband grating based on periodically poled LiNbO3 is reported. According to the wave- coupling theory, the analytical expression of the diffraction intensity for the grating is derived, and the numerical results show that the diffraction spectrum of the grating can be tuned by an applied eAn electrically controlled broadband grating based on periodically poled LiNbO3 is reported. According to the wave- coupling theory, the analytical expression of the diffraction intensity for the grating is derived, and the numerical results show that the diffraction spectrum of the grating can be tuned by an applied electric field. For example, with an applied voltage of 310 V, the diffraction efficiency of first order spectrum is greater than 60% over the band from 1.21 mm to 1.83 mm. Especially at the wavelength of 1.5 mm, it reaches 70%. With an applied voltage of 165 V, the diffraction efficiency of first order spectrum is more than 60% over the band from 0.68 mm to 0.92 mm. Particularly at the wavelength of 0.8 mm，it is up to 81% . Due to the short response time, the grating can be expected to have important applications in high-speed optical switches, wavelength division multiplexers or optical modulators..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 105001 (2015)
Design of a Varied-Line-Space Plane Grating in EUV Spectrum
Jiang Yanxiu, Bayanheshig, Yang Shuo, Zhao Xulong, Li Wenhao, and Wu Na
To make varied-line-space holographic grating which in applied in the extreme ultraviolet band (50~150 nm), a new optimization algorithm applied to spherical wavefront system is proposed, named the improved local optimization algorithm. According to the request of instruments, expected varied-line-space holographic graTo make varied-line-space holographic grating which in applied in the extreme ultraviolet band (50~150 nm), a new optimization algorithm applied to spherical wavefront system is proposed, named the improved local optimization algorithm. According to the request of instruments, expected varied-line-space holographic grating density function is built. Based on this density function, the merit function is given, of which characteristic is transforming four merit functions to one merit function which has multivariate and nonlinear constrains. Using the improved local algorithm, the error of groove density coefficient is reduced and the resolution of gratings is improved due to the weighted, the diversity of the initial value, the limitation of the recording parameters values range and the constraint of groove density coefficients. Compared with the conventional local optimization algorithm, using the improved local optimization algorithm makes absolute error between design and expected groove density in 0~0.02 line/mm range. And the order of magnitude is improved and the resolution increases from 4000 to above 17000. Results show that by adopting the suited optimization algorithm, varied-line-space plane grating with a high resolution can be made in the spherical wavefront system..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 105002 (2015)
Fiber Optics and Optical Communications
Scintillation of Partially Coherent Beam in Atmospheric Turbulence
Ke Xizheng, and Zhang Yu
Based on the modified Rytov variance, the effect of partially coherent beam through atmospheric turbulence on log-intensity variance is studied using the Gaussian-Schell model (GSM) beam and Andrews model. The log-intensity variance is deduced and discussed when partially coherent beam goes through weak turbulence and Based on the modified Rytov variance, the effect of partially coherent beam through atmospheric turbulence on log-intensity variance is studied using the Gaussian-Schell model (GSM) beam and Andrews model. The log-intensity variance is deduced and discussed when partially coherent beam goes through weak turbulence and strong turbulence. The results show that the log-intensity variance of the partially coherent beam is lower than that of the fully coherent beam under the same turbulence conditions, as the light source coherence becomes worse, the log-intensity variance and the influence of turbulence plane decreases. The light source coherence, atmospheric refractive index structure constant and other parameters all have great effect on scintillation in both of weak and strong turbulence..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 106001 (2015)
Research on Peak-to-Average Power Ratio Reduction Performance for 100-Gb/s High-Speed PDM-CO-OFDM Systems
Tong Zhengrong, Liu Yinghui, and Cao Ye
The iterative partial transmit sequence (IPTS) clipping algorithm is used to reduce the peak- toaverage power ratio (PAPR) of 100- Gb/s high- speed polarization division multiplexing coherent optical orthogonal frequency division multiplexing (PDM- CO- OFDM) system. PAPR, bit error rate (BER), and nonlinearity performaThe iterative partial transmit sequence (IPTS) clipping algorithm is used to reduce the peak- toaverage power ratio (PAPR) of 100- Gb/s high- speed polarization division multiplexing coherent optical orthogonal frequency division multiplexing (PDM- CO- OFDM) system. PAPR, bit error rate (BER), and nonlinearity performance are analyzed. Simulation results demonstrate that the PAPR, BER, and nonlinearity performance of IPTS clipping algorithm are superior to those of clipping algorithm. At the complementary cumulative distribution function (CCDF) of 0.0001, the threshold value of IPTS clipping algorithm is optimized by 0.62 dB compared with clipping algorithm. Compared with original signal, the maximum peak power of IPTS clipping algorithm is reduced by 2.63 dBm. In the same conditions, the needed optical signal to noise ratio (OSNR) of IPTS clipping algorithm is 12.28 dB to reach the BER level of 10- 3. However, the minimum BER of clipping algorithm is only 1.55× 10- 3. At the launch power of - 1 dBm, the Q value of IPTS clipping algorithm is improved by 0.28 dB compared with clipping algorithm..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 106002 (2015)
New Method to Improve the Performance of Brillouin Optical Time Domain Reflectometer System
Li Yongqian, Li Xiaojuan, and An Qi
A new method to improve the performance of Brillouin optical time domain reflectometer (BOTDR) system is proposed, by introducing the reported pulsed pre-pump technique into the well known structure based on the consideration of Brillouin spectrum reshaping. In this method, the optical pulse launched into the fiber is A new method to improve the performance of Brillouin optical time domain reflectometer (BOTDR) system is proposed, by introducing the reported pulsed pre-pump technique into the well known structure based on the consideration of Brillouin spectrum reshaping. In this method, the optical pulse launched into the fiber is provided by electro-optical modulation with a step pulse composed of a pre-pump pulse and a sensing pulse. The reshaping of Brillouin spectrum and the amplification of sensing signal are achieved through the stimulated Brillouin scattering (SBS) interaction between pre-pump pulse and sensing pulse, and the contradiction between spatial resolution and measurement accuracy can be solved, effectively. Meanwhile, the signal to noise ratio and the sensing distance can be enhanced significantly. SBS models under steady-state are solved by transient analysis in the step pulse modulation BOTDR, the optimal design of step pulse is made, and the system performance is compared with those in rectangular pulse and Lorentz pulse modulation structures. The results show that with a step pulse synthesized by a pre-pump pulse with a width of 50 ns and a peak power of 0.2 W and a sensing pulse with the corresponding parameters of 2 ns and 1 W, Brillouin spectrum width can be as narrow as about 44 MHz, and the signal to noise ratio at the end of 10 km single mode fiber can be 7.97 dB higher than that in the rectangular pulse structure. Finally, the feasibility of the proposed method is demonstrated experimentally..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 106003 (2015)
MIMO Visible Light Wireless Communication System Employed Camera-Based Receiver
Gao Junying, Wang Dechang, and Yao Jianguo
A novel multiple-input multiple-output (MIMO) visible light communication (VLC) system is proposed, by applying multi-lights. n lights are simulated by software and different signal sequences are sent, respectively. In the receiver, camera is employed to receive the wireless signals. After that, the image processing alA novel multiple-input multiple-output (MIMO) visible light communication (VLC) system is proposed, by applying multi-lights. n lights are simulated by software and different signal sequences are sent, respectively. In the receiver, camera is employed to receive the wireless signals. After that, the image processing algorithms are defined to recognize and restore the signal sequences and the n signal sequences can be recovered. The result demonstrates that the minority error codes appeared in the experiments all can be rectified accurately, and the signal sequences sent in the transmitting end all can be restored in the receiving end exactly. The presented approach evades the layout problem of lighting, the synchronization problem, and the multipath interference problem existed in the presented system based on the photodiode receiver by altering the mechanism of signal receiving. The way of transferring and receiving the signals based on multi-channels presented increases the use ratio of light source, and it possesses more practical value because of its operability..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 106004 (2015)
Diversity Reception Technology over Atmospheric Turbulence Channels in Wireless Optical Communication
Ke Xizheng, and Liu Mei
The light scintillating caused by atmospheric turbulence, absorption and scattering can increase the energy attenuation of the laser beam and decrease the signal to noise ratio(SNR). Diversity reception technology can overcome this effect, effectively. Using on off keying (OOK) modulated, free space optical communicatiThe light scintillating caused by atmospheric turbulence, absorption and scattering can increase the energy attenuation of the laser beam and decrease the signal to noise ratio(SNR). Diversity reception technology can overcome this effect, effectively. Using on off keying (OOK) modulated, free space optical communication (FSO) system with spatial diversity based on the K-distributed model is established. The error performances among three linear combining technologies as maximal ratio combining (MRC), equal gain combining (EGC) and selection combining (SC) for different channel parameters and different detectors are analysed. The simulation results show that the performance of the system by MRC is the best, followed by EGC, and SC combining is poor. Spatial diversity has strong ability to improve the performance and resistance to atmospheric channel decline..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 106005 (2015)
Study of Synchronous Technology in High-Speed Continuous Variable Quantum Key Distribution System
Liu Youming, Wang Chao, Huang Duan, Huang Peng, Feng Xiaoyi, Peng Jinye, Cao Zhengwen, and Zeng Guihua
In high-speed continuous-variable quantum key distribution system, frame synchronous technology is one of the most important technologies to ensure accurate access to effective information carried by quantum signals. A simple and efficient frame synchronization theoretical method based on the measurement results of theIn high-speed continuous-variable quantum key distribution system, frame synchronous technology is one of the most important technologies to ensure accurate access to effective information carried by quantum signals. A simple and efficient frame synchronization theoretical method based on the measurement results of the quadratures of coherent states with balanced homodyne detector is proposed. This synchronous method in the continuous-variable quantum key distribution system is experimentally realized with repetition frequency of 25 MHz based on Gaussian modulation coherent states, and the performance of the proposed synchronous method is analyzed in detail. The results show that the proposed frame synchronization method can effectively overcome the disturbance from the environmental factor in the key distribution of quantum signals, and thus realizes efficient frame synchronization between the two communicators..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 106006 (2015)
Image Processing
A Method of Super-Resolution Reconstruction for Remote Sensing Image Based on Non-Subsampled Contourlet Transform
Zhou Jinghong, Zhou Cui, Zhu Jianjun, and Fan Donghao
An improved method is proposed to solve the existing problem that the fusion process is too simple in non-subsampled contourlet transform (NSCT) super-resolution reconstruction. The magnitude of the spatial frequency reflects the degree of image detail richness, and the improved method uses this magnitude of regional wAn improved method is proposed to solve the existing problem that the fusion process is too simple in non-subsampled contourlet transform (NSCT) super-resolution reconstruction. The magnitude of the spatial frequency reflects the degree of image detail richness, and the improved method uses this magnitude of regional window as the standard of the weight, so the adaptive weighted fusion method is applied to the obtained high frequency by NSCT decomposition of image. The adaptive weighted fusion method and NSCT analysis are assembled to achieve image super-resolution reconstruction, in this process, each corresponding high-frequency image is fused by adaptive weighted fusion method, and the low-frequency image is processed to get a mean. The super-resolution image is acquired by inverse NSCT to both the low frequency images and high frequency images. Through simulation and engineering practice, the improved method proves to be feasible and effective..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 110001 (2015)
A Defogging Method Based on Hyperspectral Unmixing
Feng Weiyi, Chen Qian, He Weiji, Gu Guohua, Zhuang Jiayan, and Xu Shuangshuang
For the problem of low visibility caused by fog weather, a defogging method based on hyperspectral image unmixing technique is proposed. A physical model of the imaging sensor in fog weather is established, and the mathematical model of linear spectral mixture with fog endmember is unmixed. The fog endmember obtained fFor the problem of low visibility caused by fog weather, a defogging method based on hyperspectral image unmixing technique is proposed. A physical model of the imaging sensor in fog weather is established, and the mathematical model of linear spectral mixture with fog endmember is unmixed. The fog endmember obtained from the abundance inversion is removed. The defogging image is achieved after the abundance adjustment of the remaining endmembers. Compared with the fog/cloud removal based on the single- band or full-color image, the physical meaning of this approach is clearer. From the objective evaluation, it can be seen that the defogging effect of the proposed method is good. The defogging image has richer details..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 110002 (2015)
A Stereo Matching Algorithm Using Improved Gradient and Adaptive Window
Zhu Shiping, and Li Zheng
Stereo matching is one of the most active research areas in computer vision. As it is an ill problem, a perfect solution does not exist until now. Aiming at solving the problem of low accuracy and sensitivity to radiometric distortion caused by existing local matching algorithm, a new stereo matching algorithm using imStereo matching is one of the most active research areas in computer vision. As it is an ill problem, a perfect solution does not exist until now. Aiming at solving the problem of low accuracy and sensitivity to radiometric distortion caused by existing local matching algorithm, a new stereo matching algorithm using improved gradient cost and adaptive window is presented here. Besides of the magnitude information in traditional gradient cost, the phase information is introduced and the taw matching cost is transformed to eliminate outliers. An adaptive window for every pixel is constructed by utilizing the image structure and color intensity. An effective disparity refinement method based on local disparity histogram is employed, which gains disparity maps with high accuracy. The experimental results show that the proposed method has an average error of 6.1% in the Middlebury testing benchmark, while keeping strong robustness to radiometric distortion..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 110003 (2015)
Geometric Correction Method for Oscillation Distortion of Remote Sensing Images Using Compressive Sampling
Wang Pu, An Wei, Deng Xinpu, and Guo Jing
Satellite vibration and scan mirror oscillation can cause oscillation distortions of remote sensing imagery. These distortions are difficult to be corrected by common geometric correction methods. A geometric correction method using compressive sampling is proposed. In this method, geometric correction is performed witSatellite vibration and scan mirror oscillation can cause oscillation distortions of remote sensing imagery. These distortions are difficult to be corrected by common geometric correction methods. A geometric correction method using compressive sampling is proposed. In this method, geometric correction is performed with rational function model (RFM). The biases between the image coordinates and project coordinates of ground control points (GCPs) are calculated with the original RFM. The bias is called projection bias. The projection biases at the GCPs are regarded as measurements. By using the technique of compressive sampling, the projection biases of every pixel can be reconstructed, and the RFM is compensated according to projection biases. The remote sensing imagery is rectified with the compensated RFM. Through compensation, the errors of RFM which caused by oscillation distortions are eliminated and the performance of geometric correction is improved. The method is proved effective by using real remote sensing images. Based on simulated images, the effect of GCPs distribution and number on geometric correction is also analyzed..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 110004 (2015)
Imaging Systems
Study on Evaluation of Motion Blur in Binocular Parallax Based Stereoscopic Displays
Xia Zhenping, Li Xiaohua, Chen Lei, and Wang Jian
To evaluate the motion image quality of binocular parallax based stereoscopic displays more objectively and precisely, the evaluation method is established based on two dimensional (2D) motion blur evaluation model and three dimensional (3D) perception experiment. The 2D motion blur simulation is applied on the binoculTo evaluate the motion image quality of binocular parallax based stereoscopic displays more objectively and precisely, the evaluation method is established based on two dimensional (2D) motion blur evaluation model and three dimensional (3D) perception experiment. The 2D motion blur simulation is applied on the binocular parallax images, and then displayed on the 3D space. After that, the comparison perception experiment is completed between real motion blur perception and simulation. The experiment result shows that factor“parallax”has no significant effect on motion blur perception. Based on these, the average motion blur level of two parallax images is used to establish objective motion blur evaluation method of binocular parallax based stereoscopic displays. The proposed method makes the motion image quality evaluation of binocular parallax based stereoscopic displays more objective and precise. Meanwhile, it provides reference for the motion image quality improvement in stereoscopic displays..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 111001 (2015)
Instrumentation, Measurement and Metrology
Point Diffraction Interferometry Based on Phase Demodulation Technique for Circular Carrier Interferogram
Li Jinpeng, Chen Lei, Zhu Wenhua, and Hu Fen
In order to mearsure emerging wavefront and dynamic wavefront of optical system, a point diffraction interferometry based on technique for demodulating circular carrier interferogram is proposed. Circular carrier is introduced in interferogram by shifting point diffraction plate in longitudinal direction in conventionaIn order to mearsure emerging wavefront and dynamic wavefront of optical system, a point diffraction interferometry based on technique for demodulating circular carrier interferogram is proposed. Circular carrier is introduced in interferogram by shifting point diffraction plate in longitudinal direction in conventional point diffraction interferometer. The circular carrier interferogram is converted into quasi linear carrier interferogram after quadratic polar coordinate transforming, meanwhile the continuous spectrum is converted into quasi discrete spectrum in frequency domain. Fourier transform method is then applied to extract phase. Simulated wavefront is generated randomly based on 36 Zernike polynomials, and root mean square value of phase recovery error is 0.002l on condition that defocus is 17l. Testing the emerging wavefront of F/10 lens is realized by using this method and the result is in agreement with that obtained by SID-4 wavefront sensor; dynamic measuring of organic glass absorptive character is also realized . This method can be applied to test optical system and measure real-time wavefront..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 112001 (2015)
A Method of Gamma Correction in Fringe Projection Measurement
Cui Yanjun, Zhang Wenfeng, Li Jianxin, Zhu Rihong, Wang Ran, and Zhang Chunhui
The Gamma distortion is an important influencing factor of accuracy in fringe projection measurement. To improve the accuracy of measurement, an accurate and simple Gamma correction method is studied by analyzing the relationship between Gamma coefficient and harmonic coefficient. The accuracy and reliability of this mThe Gamma distortion is an important influencing factor of accuracy in fringe projection measurement. To improve the accuracy of measurement, an accurate and simple Gamma correction method is studied by analyzing the relationship between Gamma coefficient and harmonic coefficient. The accuracy and reliability of this method is verified through the simulation results. Finally, experimental work is done with this method. Compared with the retrieval phase without Gamma correction, the conclusion can be made that this method can effectively restrain the Gamma distortion of the system and improve the measurement precision..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 112002 (2015)
Solar Flux Measurement Method for Concentrated Solar Irradiance in Solar Thermal Power Tower System
Xiao Jun, Wei Su, Wei Xiudong, Ren Lanxu, and Lu Zhenwu
A solar flux measurement method for the concentrated solar irradiance based on indirect measurement principle is proposed. This method does not require additional thermal flux meters or energy sensors to calibrate the camera, which simplifies the measurement process. It takes images of the sun and the concentrated solaA solar flux measurement method for the concentrated solar irradiance based on indirect measurement principle is proposed. This method does not require additional thermal flux meters or energy sensors to calibrate the camera, which simplifies the measurement process. It takes images of the sun and the concentrated solar irradiance beam by using the same camera and the same camera settings. Combining with the direct normal irradiance of the sun, it can figure out the scale factor between the pixel grey values of the camera and the flux density. And then, it obtains the flux distribution of the beam. The measurement principle of this technique is introduced in detail, and a testing platform is built. The flux map of a piece of small heliostat is measured, and the feasibility and correctness of this method are verified. The experimental results indicate that the relative error of the peak flux measured by this method is less than 5%, and the repeatability error is about 1%..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 112003 (2015)
New Calibration Method for Line Structured Light Sensor Based on Planar Target
Chen Tianfei, Zhao Jibin, and Wu Xiang
Among the existing calibration methods for line structured light sensor, the accuracy of calibration points in laser plane has direct influence on the calibration result of line structured light sensor. A new calibration method for line structured light sensor based on planar target is proposed. The proposed approach dAmong the existing calibration methods for line structured light sensor, the accuracy of calibration points in laser plane has direct influence on the calibration result of line structured light sensor. A new calibration method for line structured light sensor based on planar target is proposed. The proposed approach does not need to calculate the calibration points in laser plane and the extrinsic camera parameters repeatedly. Planar target is moved to capture laser stripe with different directions and compute the vanish points, and then the normal vector of laser plane is calibrated by the way of fitting straight using the vanish lines. After that, distances between each calibration points are computed based on the principle of cross ratio invariance, and the remaining parameters are calculated according to the distances. Considering the influence of error propagation, an optimized objective function is defined with the obtained parameters as initial value. The results of comparative experiment show that the proposed method has higher calibration accuracy, and the root mean square measurement error is 0.0306 mm. Besides that, the calibration process is simple with low computational complexity, and suitable for calibration on spot..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 112004 (2015)
Multi-Target Self-Determination Orientation System Based on Airborne Photoelectric Imaging Platform
Zhou Qianfei, Liu Jinghong, Xiong Wenzhuo, and Song Yueming
In order to achieve multiple targets in real-time or near real-time orientation, a multi-target selfdetermination orientation system based on airborne photoelectric imaging platform is established and a precise multi-target self-determination orientation model based on line-of-sight vector of pixel is proposed for the In order to achieve multiple targets in real-time or near real-time orientation, a multi-target selfdetermination orientation system based on airborne photoelectric imaging platform is established and a precise multi-target self-determination orientation model based on line-of-sight vector of pixel is proposed for the system.Using target detection algorithms to obtain the precise pixel coordinates of each target, the line-of-sight vectors of each target are constructed based on image forming principles for single-plane array charge coupled device(CCD) sensors, and the view angles of pixel between the main target at image center and other targets are calculated.Combining with the azimuth angle, elevation angle and the distance between the main target and the photoelectric platform, the distance and angle relations between other targets and the photoelectric platform are calculated. Based on the position and attitude information of aircraft, which is obtained by the global positioning system (GPS)heading and attitude measuring system, the homogeneous coordinate transformation method is applied to calculate the geodetic coordinates of multiple targets in a single image. For the orientation error caused by the lens distortion,a method based on the lens distortion ratio is presented to correct it. When flying at an altitude of 1100 m, the circular error probable (CEP) of multi-target self-determination orientation system is approximately 28.74 m, and the height error is about 18 m. It can geolocate 50 targets in a single image in real-time. When the lens distortion ratio is 2%, the CEP of multiple targets position data is reduced by 7% after correcting the lens distortion. The multitarget self-determination orientation method has high efficiency and is convenient for engineering application..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 112005 (2015)
Research on Orbit Determination Technology for Space Target Based on Method of Tracking with Double Satellites and Double Cameras
Wang Weibing, Wang Tingfeng, and Guo Jin
A kind of orbit determination technology is mainly researched for space target based on method of tracking with double satellites and double cameras in space- based surveillance. The physical idea is that the absolute motion information of space target in earth coordinate system can be computed completely through a serA kind of orbit determination technology is mainly researched for space target based on method of tracking with double satellites and double cameras in space- based surveillance. The physical idea is that the absolute motion information of space target in earth coordinate system can be computed completely through a series of coordinate transformations and data process. The data are from relative azimuth point information of target in satellite that are measured with optical measurement devices and information of satellite attitude angles and rotation angles of opto- electrical tracking frame that are sensed by corresponding angle sensors. Measurement equation of target in earth coordinate system is gained after describing physical model, coordinate systems and deriving principle of orbit determination in turn. Furthermore, mathematic simulation is researched after analyzing many models including space- based surveillance satellite orbit, opto- electronic tracking and optical imaging. The computation results show the feasibility of this method..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 112006 (2015)
Study of Anamorphose Correction of Astigmatism-Corrected Czerny-Turner Imaging Spectrometer
Tang Yi, Zheng Cheng, Nan Yibing, Li Fei, and Guo Lei
Correcting astigmatism by using Czerny- Turner imaging spectrometer can change system focal length, which leads to the difference of magnification in tangential direction and sagittal direction of the image. The common characteristics of astigmatism correction theories of Czerny- Turner imaging spectrometers (using cylCorrecting astigmatism by using Czerny- Turner imaging spectrometer can change system focal length, which leads to the difference of magnification in tangential direction and sagittal direction of the image. The common characteristics of astigmatism correction theories of Czerny- Turner imaging spectrometers (using cylindrical mirror and toroidal mirror) are analyzed. And the correction formulas, methods of anamorphose and their common characteristics are given. The validity of correction formula of anamorphose are verified with theoretical calculation, ray tracing simulation, and actual measurement. Meanwhile, this method of image correction is useful to the anamorphose correction research of off- axis structure dispersion imaging spectrometer in other operating conditions of collimation light..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 112007 (2015)
A Method for Compensating Interpolation Error of Absolute Linear Encoder
Qiao Dong, Xu Zhijun, Wu Hongsheng, Zeng Qifeng, Liu Yang, and Sun Qiang
In order to improve the interpolation accuracy of the absolute linear encoder, a compensating method for the interpolation error is presented. By using the Fourier theory to analyze the A and B moire fringe signals, the moire fringe signal models for the absolute linear encoder is set up. By correcting the phase, ampliIn order to improve the interpolation accuracy of the absolute linear encoder, a compensating method for the interpolation error is presented. By using the Fourier theory to analyze the A and B moire fringe signals, the moire fringe signal models for the absolute linear encoder is set up. By correcting the phase, amplitude, harmonics and direct current components of the signal modes, the ideal signal models are obtained. By comparing the interpolation position of the practical and ideal signal models, the interpolation error of the absolute linear encoder is obtained. After that, by compensating the interpolation position according to the obtained error, the interpolation accuracy can be improved remarkably. The JC09 absolute linear encoder is used to test and verify the presented method. The test results show that the interpolation relative error can be decreased from 2.70% to 1.05% . It demonstrates that this method can improve the interpolation accuracy significantly. In addition, due to the simple theory, the method can be easily realized..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 112008 (2015)
Lasers and Laser Optics
Numerical Analysis on the Thermal-Deformation of Semiconductor Refrigerated Mirror
Nie Shanjun, Guo Jin, Shao Junfeng, Wang Tingfeng, and Tang Wei
In order to reduce the thermal-deformation of the silicon mirror, a finite element method analysis system about the thermal-deformation of the mirror is established. The thermal-deformation of the mirror with different semiconductor refrigeration powers are compared, then, for the TEM00 mode Gaussian beam whose radius In order to reduce the thermal-deformation of the silicon mirror, a finite element method analysis system about the thermal-deformation of the mirror is established. The thermal-deformation of the mirror with different semiconductor refrigeration powers are compared, then, for the TEM00 mode Gaussian beam whose radius is 1/3 of the mirror, the structure of the mirror is optimized when the absorbed power is 50 W. The optimized mirror in the TEM00 mode Gaussian beam of different parameters and TEM10, TEM11 mode Hermite-Gaussian beam under the irradiation of the thermal deformation are analyzed. The simulation results show that when the semiconductor refrigeration power equals the power of the laser absorbed and lags behind the laser works, the deformation is largely improved and is relatively stable at last. In addition, when a circular area with thickness of 1.4 mm and inner radius of 25 mm is removed at the backside of the mirror, the peak valley (PV) value is 0.005 mm. The PV value of the thermal distortion of the optimized mirror is reduced in a certain extent under other laser radiations. For TEM00 mode Gaussian beam and TEM10, TEM11 mode Hermite-Gaussian beam, the mirror satisfies the requirement of the optic system..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 114002 (2015)
Machine Vision
Five-Point Relative Orientation Based on Forward Intersection
Zhang Zhengyu, Zhu Long, Huang Xuhui, Lai Hanxuan, and Zhao Tao
The algorithm of five-point relative orientation is a classical problem for photogrammetry and computer vision. The polynomial is used by the traditional method of five-point relative pose, which causes the polysemia. Therefore, a new method of five-point relative orientation based on the forward intersection is presenThe algorithm of five-point relative orientation is a classical problem for photogrammetry and computer vision. The polynomial is used by the traditional method of five-point relative pose, which causes the polysemia. Therefore, a new method of five-point relative orientation based on the forward intersection is presented, the coplanar equations with forward intersection constraints are set up, whose optimization function is derived, and the least square generalized inverse method is employed to achieve relative orientation parameters with five homologous points. This method has been demonstrated by 8 groups of experiments which use nonmetric camera Nikon D80, the relative three dimensional (3D) model successfully only with 5 homologous points of two images with different view angles, and the standard uncertainty of measured errors for the two given rules (0.92 m) is 0.28±0.24 mm. Compared with the existing five-point algorithm, this method can ensure the intersections for the five homologous rays without polysemia, its accuracy and robustness is good, and has practical value..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 115001 (2015)
Separation Algorithm of Traffic Signs Based on Curvature Scale Space Corner Detection
Li Houjie, Qiu Tianshuang, Song Haiyu, Wang Peichang, and Wang Pengjie
In view of the detection rate degradation of traffic sign due to multiple signs interconnection, a separation algorithm based on curvature scale space (CSS) corner detection is proposed. The candidate regions of multiple signs interconnection are automatically identified based on red green blue (RGB) normalization coloIn view of the detection rate degradation of traffic sign due to multiple signs interconnection, a separation algorithm based on curvature scale space (CSS) corner detection is proposed. The candidate regions of multiple signs interconnection are automatically identified based on red green blue (RGB) normalization color segmentation algorithm and region feature decision criterion. The edge smoothing and contour tracking for the extracted target region are performed. For the obtained contour, the corner detection by using the CSS corner detector based on global and local curvature properties is conducted. And according to the criterion for judging the convexity- concavity of corner and separation points pair matching condition, the separation points pair between the interconnection traffic signs is extracted from the detected corners. The separation line between the separation points pair is achieved by adopting Bresenham algorithm, thus the traffic signs are separated by using the line. Experimental results verify the effectiveness of our method. The proposed method overcomes the problem of the traffic signs over- separation and improves the overall detection performance compared with the existing separation algorithm based on watershed transform and the improved adaptive separation algorithm..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 115002 (2015)
Three Dimensional Rigid Objects Pose Tracking and Optimization Based on Multilevel Line Representation and M-Estimation
Zhang Yueqiang, Su Ang, Liu Haibo, Shang Yang, and Yu Qifeng
To track and estimate the pose and position of known rigid objects efficiently in complex environment, a method coupled three dimensional (3D) particle filter (PF) framework with M-estimation optimization in a closed loop is proposed. A novel similarity observation model is constructed based on multilevel line represenTo track and estimate the pose and position of known rigid objects efficiently in complex environment, a method coupled three dimensional (3D) particle filter (PF) framework with M-estimation optimization in a closed loop is proposed. A novel similarity observation model is constructed based on multilevel line representation; line correspondences between 3D model edges and two dimensional (2D) image line segments are received easily based on the tracking state of PF. After that, line correspondences are provided for M-estimation to optimize the pose and position of objects. The optimized particles are fused into the particle filter framework according to the importance sampling theory. Moreover, to speed up the proposed method, line detection and search space is limited in a local region of interest (ROI) predicted by PF. Experiments show that the proposed method can effectively track and accurately estimate the pose of freely moving objects in unconstrained environment. Comparisons on synthetic and real images demonstrate that proposed method greatly outperforms the state-of-art method in accuracy and efficiency..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 115003 (2015)
Accelerative Orthogonal Iteration Algorithm for Camera Pose Estimation
Li Xin, Long Gucan, Liu Jinbo, Zhang Xiaohu, and Yu Qifeng
An accelerative orthogonal iteration algorithm about the classical and wildly used orthogonal iteration algorithm for camera pose estimation is proposed for real time computation. The key idea is to integrate the steps in each iteration. The repetitive computation in each iteration can be abstracted and done before iteAn accelerative orthogonal iteration algorithm about the classical and wildly used orthogonal iteration algorithm for camera pose estimation is proposed for real time computation. The key idea is to integrate the steps in each iteration. The repetitive computation in each iteration can be abstracted and done before iteration. The computational complexity of each iteration is reduced from O(n) to O(1). So that, more iteration can be done in short time, and the accuracy is improved as well. The contrastive simulation and real data experiments show the efficiency and accuracy of the accelerative algorithm. Experimentally, the accelerative algorithm with the robust perspective n point (RPnP) initialization has nearly the same accuracy as maximum likelihood estimation (MLE), and is the fastest algorithm when there are few control points..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 115004 (2015)
Hand Vein Recognition Based on Three Dimensional Point Clouds Matching
Zhang Qishen, Zhou Ya, Hu Xiaoming, and Wang Danting
In order to solve the problem of high false rejection rate and not supporting large data base registration in existing hand vein recognition system, a binocular stereoscopic vision device for hand vein three dimensional (3D) point can reconstruction is proposed, along with the hand vein 3D point cloud matching algorithIn order to solve the problem of high false rejection rate and not supporting large data base registration in existing hand vein recognition system, a binocular stereoscopic vision device for hand vein three dimensional (3D) point can reconstruction is proposed, along with the hand vein 3D point cloud matching algorithm. The hand is lighted by an 850 nm light emitting diode (LED) light source, binocular images for 3D reconstruction are obtained by the stereo cameras. The hand vein′s spatial structure is described by hand veins feature, an optimized kernel correlation analysis approach is proposed for 3D point cloud matching. Experimental results of 200 different point clouds data show the proposed system is feasible and effective, the recognition rate is 98% , false rejection rate is 2% and the false accept rate is 0% , the feature′ s dimension is ranged from 8000 to 12000, which is higher than that of scale invariant feature transform (SIFT). The proposed system provides a possibility for large database recognition..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 115005 (2015)
Materials
First Principle Study on Electronic Structure and Optical Properties of β-FeSi2 with Doping Rare Earth (Y、Ce)
Zhang Chunhong, Zhang Zhongzheng, Deng Yongrong, Yan Wanjun, Zhou Shiyun, Gui Fang, and Guo Benhua
By using the first principle pseudo-potential plane-wave method, the geometrical structure, electronic structure and optical properties of β-FeSi2 with doping rare earth (Y、Ce) are calculated and analyzed. The calculated results of the geometrical structure show that the lattice constants change, the volume of lattice By using the first principle pseudo-potential plane-wave method, the geometrical structure, electronic structure and optical properties of β-FeSi2 with doping rare earth (Y、Ce) are calculated and analyzed. The calculated results of the geometrical structure show that the lattice constants change, the volume of lattice reduces. Electronic structure calculation indicates that band structure near the gap becomes complex, and bandgap becomes narrow obviously. The total density of state changes, and the density of states for Y-4d and Ce-4f are mainly contributing to the Fermi energy level. Optical properties calculation indicates that the static dielectric constant increases, the peak of the imaginary part of dielectric function ε2 decreases and moves to a lower energy, the refractive index n0 increases significantly and the peak of k decreases. These results offer theoretical data for experimental study β-FeSi2 doped with rare earth modification..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 116001 (2015)
Study on Chemical Composition of White Porcelain in Beijing Longquanwu Kiln Site
Cheng Lin, Li Meitian, Li Longhui, Wang Junling, Li Rongwu, and Qi Honghao
The chemical composition of ancient white porcelain in Beijing Longquanwu kiln in 4 different historical periods of early Liao Dynasty, middle Liao Dynasty, later Liao Dynasty and Jin Dynasty are analyzed by micro-X-ray fluorescence focused by polycapillary optics. The experimental data are carried out by factor analysThe chemical composition of ancient white porcelain in Beijing Longquanwu kiln in 4 different historical periods of early Liao Dynasty, middle Liao Dynasty, later Liao Dynasty and Jin Dynasty are analyzed by micro-X-ray fluorescence focused by polycapillary optics. The experimental data are carried out by factor analysis. The results show that ancient white porcelain in different historical periods in Beijing Longquanwu kiln can be divided into two sorts according to their chemical compositions. The one center of ancient white porcelain is that of early Liao Dynasty, and the other is that of middle Liao Dynasty. The chemical composition of ancient white porcelain in later Liao Dynasty and Jin Dynasty are similar to that of early Liao and middle Liao, respectively. There is no significant difference of chemical composition of ancient white porcelain between the ancient fine white porcelain and ancient coarse white porcelain. The experimental result does not support the hypothesis that Beijing Longquanwu kiln is GUAN kiln in history. Moreover, the high content of minor element Sr is the characteristic of chemical composition of ancient white porcelain in Beijing Longquanwu kiln..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 116002 (2015)
TE Polarization Perfect Absorption with Dual-band in Metal-Photonic Crystal-Metal Structure
Lu Suqing, Chao Xiaogang, Chen Xianfeng, and Tang bin
Design of a one-dimensional metal-photonic crystal-metal(M1-PC-M2) structure is presented. The existence of optical Tamm state (OTS), corresponding to dips in the reflection spectra of the structure, which is determined by the transfer- matrix method. Numerical results show that two OTSs appear at the interface betweenDesign of a one-dimensional metal-photonic crystal-metal(M1-PC-M2) structure is presented. The existence of optical Tamm state (OTS), corresponding to dips in the reflection spectra of the structure, which is determined by the transfer- matrix method. Numerical results show that two OTSs appear at the interface between the metal film and photonic crystal, transverse electric (TE) polarization perfect absorption with dualband as high as over 95% is achieved when 45 nm≤dM1≤52 nm, and two absorption wavelengths are near 743.1 nm and 745.7 nm. As the incident angles increase from 0° to 60° , the absorption of two OTSs can still stay above 95%, the M1-PC- M2 structure achieving TE polarization perfect absorption of two OTSs simultaneously, and the blue- shifts of both absorption peaks occurs. When the number of period of photonic crystal is between seven and fifteen, TE polarization perfect absorption with dual-band is always accomplished..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 116003 (2015)
Geometrical Structure, Vibrant Frequency and Optical Spectrum of Mgn(2≤n≤15) Clusters
Zhai Zhongyuan, Zhang Jianting, and Sheng Yong
The geometrical structure, stability, vibrant frequency and optical spectrum of Mgn(2≤n≤15) clusters are studied by the B3LYP method of the density functional theory (DFT) at 3-21g and lanl2dz levels to search for the stable structures and the magic clusters. The spectroscopic properties of the structures are investigaThe geometrical structure, stability, vibrant frequency and optical spectrum of Mgn(2≤n≤15) clusters are studied by the B3LYP method of the density functional theory (DFT) at 3-21g and lanl2dz levels to search for the stable structures and the magic clusters. The spectroscopic properties of the structures are investigated in detail. The results indicate that the consequences computed by the two sets at ground state are identical to a great degree and the slight difference is discovered only in second-order energy difference (D2E). In addition, the bond length of Mgn clusters calculated at lanl2dz level is longer than that at 3- 21g level. The clusters including Mg4, Mg10, and Mg15 are more stable than others, and Mg4 and Mg10 are the magic clusters. All of the clusters do not only have infrared activity but also have Raman activity except Mg2 cluster. Through the optical spectrum analysis of Mg4, Mg5, Mg7, Mg9, Mg10, Mg15 clusters, it is found that the Mg10 cluster has the most infrared spectral peaks and the Mg15 cluster has the most intensive spectral peaks..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 116004 (2015)
Synthesis, Characterization, and Luminescence Properties of Rare-Earth Europium Aromatic Carboxylate Organic Complexes with 1, 10-phenanthroline
Wu Shengnan, Chen Yongjie, Xing Zhenfang, Cao Shuang, Geng Xiujuan, Xie Ying, and Li Yue
A series of rare-earth europium organic coordination complexes with the general formula EuL3phen·H2O(where the first free ligand L=PMBA, PCBA, PBrBA, PABA, the second free ligand phen=1,10-phenanthroline; PMBA=p-methylbenzoic acid, PCBA=p-chlorobenzoic acid, PBrBA=p-bromobenzoic acid, PABA=p-aminobenzoic acid) areA series of rare-earth europium organic coordination complexes with the general formula EuL3phen·H2O(where the first free ligand L=PMBA, PCBA, PBrBA, PABA, the second free ligand phen=1,10-phenanthroline; PMBA=p-methylbenzoic acid, PCBA=p-chlorobenzoic acid, PBrBA=p-bromobenzoic acid, PABA=p-aminobenzoic acid) are prepared via solvothermal synthesis procedure. The composition and structure of the resulting complexes are investigated by various means including elemental analysis, infrared (IR) spectroscopy and thermogravimetric analysis. All the aromatic carboxylic acid ligands and phen are coordinated to Eu3 + . In addition, the europium complex doesn′t decompose until 318 ℃，which indicates that the complex has a good thermal stabilization. The absorption properties of ultraviolet light of four kinds of aromatic carboxylic acid ligands are studied. The luminescence properties of the complexes have been characterized by fluorescence spectroscopy. All the complexes can emit characteristic luminescence of Eu3+ ion, and the emission intensity of electronic-dipole transition(5D0→7F2) of the complexes Eu(PBrBA)3phen·H2O, Eu(PMBA)3phen·H2O, Eu(PCBA)3phen·H2O, and Eu(PABA)3phen·H2O in turn decreased. The international commission on illumination (CIE) chromaticity coordinates of the complexes are in the red region, and they can also emit pure red light..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 116005 (2015)
Medical Optics and Biotechnology
Preliminary Research of Subcutaneous Lipolysis Induced by Two Q-Switched Infrared Laser Pulses
Lü Tao, Chen Fang, and Zhang Wei
Superabundant fat tissues in human body affect body beauty and health. In order to enhance the efficiency of lipolysis, pulsed lasers with high absorption coefficients can be selected. But they can not easily penetrate epidermis and dermis perfectly, the lasers can not irradiate and eliminate fat finally. Based on the Superabundant fat tissues in human body affect body beauty and health. In order to enhance the efficiency of lipolysis, pulsed lasers with high absorption coefficients can be selected. But they can not easily penetrate epidermis and dermis perfectly, the lasers can not irradiate and eliminate fat finally. Based on the fundamental principles of ablative fractional photothermolysis and selective photothermolysis, focused Q-switched mid-infrared laser pulses with wavelength of 2.75 mm are used to ablate epidermis and dermis, microscopic path is formed, which can help focused Q-switched infrared laser pulses with wavelength of 2.3 mm transmit through the path without energy loss to eliminate fat tissues selectively. The treatment products can be discharged through metabolism. Microscopic treatment zones affected by adjacent tissues heal soon. The harmonious compromise between safety and validity for lipolysis treatment can be realized. The research will offer a new method for dermatologic surgery treatment..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 117001 (2015)
Optical Design and Fabrication
Optical Design of a High Resolution Space Camera
Wang Xiaokun
For a kind of high resolution space camera, on the basis of calculation and analysis of the optical system parameters, three kinds of optical system: coaxial three mirror (TMC) system, two imaging off- axis three mirror (Cook TMA) system and one imaging off-axis mirror (Wetherell TMA) system have been designed by ZemaxFor a kind of high resolution space camera, on the basis of calculation and analysis of the optical system parameters, three kinds of optical system: coaxial three mirror (TMC) system, two imaging off- axis three mirror (Cook TMA) system and one imaging off-axis mirror (Wetherell TMA) system have been designed by Zemax software, and they can satisfy the requirements of the indicators. The advantages and disadvantages of the designed optical systems are analyzed, on the basis of considering of the fabrication, testing, calibration and the technology development of space camera, the Wetherell TMA system is selected as the final plan. The shape size of the camera is 1600 mm×1230 mm×545 mm, the focal length of the system is 4375 mm, the relative aperture is 1:9.94, and the viewing angle is 2°. The property of the optical system is simulated and validated, the optical transfer function, aberration and distortion are calculated and analyzed, each indicator is excellent. Finally, the system aperture and stray light elimination are analyzed and the tolerance of the optical system is allocate reasonably..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 122001 (2015)
Optical Design of Space-Based Wide Field-of-View Differential Optical Absorption Imaging Spectrometer
Xue Qingsheng
Space-based atmospheric remote sensing urgently requires wide field-of-view differential optical absorption imaging spectrometer. The research objective is spaced-based atmospheric trace gas differential optical absorption imaging spectrometer with wide covering range and minor volume and mass. Based on the research obSpace-based atmospheric remote sensing urgently requires wide field-of-view differential optical absorption imaging spectrometer. The research objective is spaced-based atmospheric trace gas differential optical absorption imaging spectrometer with wide covering range and minor volume and mass. Based on the research objective, a wide field-of-view unabscured telecope is designed using an off-axis two-mirror system and a relay system. An optical system of space-based wide field-of-view differential optical abdorption imaging spectrometer is designed using the wide field-of-view telescope and an Offner spectral imaging system. The field of view of hyspectral imager is 60°× 0.24°, relative-aperture is 1/3, and working waveband is from 280 nm to 450 nm. Ray tracing and optimization are performed by Zemax-EE software. The root mean square (RMS) spot radius for different wavelengths are less than 5 mm for the Offner spectral imaging system. The spectral resolution is 0.692 nm, and the requirement of specification is no more than 1 nm. The modulation transfer function (MTF) for different wavelengths of imaging spectrometer is more than 0.67 at characteristic frequency in the spatial direction. The design results satisfy the requirements of imaging quality, and are suitable for the application of space-based remote sensing..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 122002 (2015)
Effects and Improvements of Coating Induced Polarization Aberration on Lithography Lens Design
Shang Hongbo, Liu Chunlai, Zhang Wei, and Chen Hua′nan
In order to achieve high imaging requirement of projection lithography lens, the impact of polarization effects induced by coatings need to be considered and analyzed during the design process.Polarization aberration theory based on the Jones matrix is first described, then the polarization aberration of a numerical apIn order to achieve high imaging requirement of projection lithography lens, the impact of polarization effects induced by coatings need to be considered and analyzed during the design process.Polarization aberration theory based on the Jones matrix is first described, then the polarization aberration of a numerical aperture (NA) of 0.75 projection lithography lens with corresponding coating is analyzed as an example. The large power and spherical aberrations induced by the coating are compensated with space and focus optimization. The scalar aberration and point spread function distortion are improved from 68.92 nm and 3.76 nm to 1.08 nm and 0.38 nm, respectively. The contrast of 90 nm dense line also increases from 0.082 to 0.876. Based on this, a method to reduce polarization aberration introduced by coating is represented, such as retardation and diattenuation. Combined films are used to control the magnitude and phase separation of the P and S component simultaneously. With this method, the contrast of the 90nm dense line is improved by 1.1%..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 122003 (2015)
Design of Staring Conformal Optical System Based on Fixed Corrector
Zhang Yu, Cui Qingfeng, and Zhu Hao
In order to enhance the imaging quality of the staring conformal optical system, a static correction method which combines the optimized inner surface of the conformal dome and fixed correctors with Zernike Fringe Sag surfaces is proposed. On the base of the relationship between the parameters of dome and the shift in In order to enhance the imaging quality of the staring conformal optical system, a static correction method which combines the optimized inner surface of the conformal dome and fixed correctors with Zernike Fringe Sag surfaces is proposed. On the base of the relationship between the parameters of dome and the shift in the direction of a ray as it passes through a conformal dome, the parameters of the inner surface of the dome are projected, which reduce some aberrations of the conformal optical system. Then, the correspondence between the Zernike Fringe polynomial terms and aberrations is used to build the fixed corrector with Zernike Fringe surfaces. Based on this method, a staring conformal optical system is designed, whose F is 1, focal length is 30 mm, the field of view is ± 35° . The characters of the aberrations are analyzed before and after correction. The result shows that this method has a good effect on correcting the main aberrations, and the modulation transfer function (MTF) of optical system is higher than 0.748 at the spatial frequency of 17 lp/mm across the entire field of view. The imaging quality is favorable..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 122004 (2015)
A Mixed Gradient Algorithm for High Performance DOE Design in Off-Axis Lithography Illumination System
Song Qiang, Zhu Jing, Wang Jian, Zhang Fang, Lü Xiangbo, Yang Baoxi, and Huang Huijie
The diffractive optical element (DOE) is widely used to generate various illumination pupils in the deep ultraviolet (DUV) projection lithography system. According to the specifications of DUV lithography machines, the designed DOE should possess high diffraction efficiency and high uniformity. Traditional algorithms sThe diffractive optical element (DOE) is widely used to generate various illumination pupils in the deep ultraviolet (DUV) projection lithography system. According to the specifications of DUV lithography machines, the designed DOE should possess high diffraction efficiency and high uniformity. Traditional algorithms such as Gerchberg- Saxton (GS) algorithm (GSA) and modified GSA get high diffraction efficiency with low non-uniformity. Global searching methods such as gene algorithm and simulated annealing algorithm need huge computing effort to receive high diffraction efficiency and high uniformity. To address these issues, a mixed gradient algorithm based on GSA is proposed. It can accelerate the rate of convergence and improve the signal to noise ratio simultaneously, and the phase retrieval image is improved. The DOEs generating conventional, quadrupole and customized illumination modes are designed and analyzed based on the proposed method, then the phase is quantized with 16 levels. The diffraction efficiency will reach 92%, and the non- uniformities of the proposed algorithm can reach 3.98% and 2.3% for the conventional and quadrupole illumination modes, respectively. The received efficiency for customized DOE is 91% , and its pattern recovery error is 5.8%. It provides a practical method of DOE design in projection lithography system..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 122005 (2015)
Methods of Correcting Between-Band Chromatic Aberration in Infrared Dual-Band Dual-Field of View Athermalized Optical Design
Qu Rui, and Deng Jian
The between- band chromatic dispersive power P is derived from the derivation of between- band chromatic aberration. A new achrothermal model considering the between-band chromatic aberration is prompted. Then, method of athermalized and multi-band zoom optical system is discussed. Based on this achrothermal model, a dThe between- band chromatic dispersive power P is derived from the derivation of between- band chromatic aberration. A new achrothermal model considering the between-band chromatic aberration is prompted. Then, method of athermalized and multi-band zoom optical system is discussed. Based on this achrothermal model, a dual-band (MWIR/LWIR) dual-field of view optical system under the requirements of F=2, 150 mm/50 mm focal length, 3.7~4.8 mm and 7.7~10.3 mm waveband is designed with optical passive athermalization technology. The optical system, which consists of 8 lenses and 3 aspheric surfaces, has good image quality and Narcissus character at each field of view at -40 ℃~60 ℃..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 122006 (2015)
Design Analysis of Double Optical Window of High Speed Aerial Remote Sensor
Xu Yulei, Wang Naixiang, and Xu Yongsen
On the operation of high-speed flight, a large amount of heat is produced due to the friction between the optical window glass and the atmosphere, by which the optical window glass deforms. Then, as light pass though the deformed window, problems as bending and difference of optical path are presented, which affect theOn the operation of high-speed flight, a large amount of heat is produced due to the friction between the optical window glass and the atmosphere, by which the optical window glass deforms. Then, as light pass though the deformed window, problems as bending and difference of optical path are presented, which affect the optical system imaging of aerial remote sensor. In order to restrain the influence, the structure of the double optical window is investigated, and the optical performance of the monolayer and double optical window is analyzed. According to the window structure, methods determining the thickness of circular and rectangular window are provided on the outside working environment as well as the influence of different window installation of thickness. The deformation of optical window on the influence of pressure and temperature is analyzed, and thermal deformation analysis of the double window is also investigated combined with the flight condition. The optical property of double window is verified and compared with the equivalent thickness of the monolayer window. Analysis results show that under the condition of airborne remote sensing device speed, the radial temperature difference and axial temperature difference of double window glass are smaller than those of the monolayer window with the same thickness. For the studied optical system, the coke quantity of double optical window glass caused by hot deformation is smaller and the effect to the modulation transfer function (MTF) of optical system is weaker. The influence of the spatial frequency ranging from 0 to 65 cycle/mm is no less than 0.3 and the relative decline of MTF is no more than 10% with spatial frequency 65 cycle/mm. The optical system of the double optical window can satisfy the use requirement in the case of without focusing. The analysis study of double optical window can be referenced in the domain of designing the optical window of aerial remote sensor..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 122007 (2015)
Optical Design of a Double-Side Fresnel Lens for Concentrator
Yu Chunyan, Cui Qingfeng, Zhu Hao, and Zhang Bo
A double-side Fresnel lens for a solar energy collector has been designed with the characteristics of lighter weight and smaller axial dimension. Rays going through the front surface ring and entering the corresponding rear surface ring, which reduces the energy loss. The energy of the solar cell obtained by the doubleA double-side Fresnel lens for a solar energy collector has been designed with the characteristics of lighter weight and smaller axial dimension. Rays going through the front surface ring and entering the corresponding rear surface ring, which reduces the energy loss. The energy of the solar cell obtained by the double-side Fresnel lens is with higher energy density. The design formula for the rear surface Fresnel structure is derived. The optical condenser performance of a double-side Fresnel lens is simulated with an optical design software LightTools. A double-side Fresnel lens with diameter of 200 mm, focal length of 120 mm and F number of 0.6 is designed as an example. The applied illumination is from 380 nm to 760 nm wavelength and with a solar angular subtense of 0.55°. Design results show that theoretical improvement in collection efficiency is 21.1% compared with that of a similar conventional Fresnel lens..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 122008 (2015)
Physical Optics
Ribbon Qausi-Non-Diffracting Beam Obtained with Elliptical Aperture and Axicon System
Xie Xiaoxia, Li Dong, and Wu Fengtie
The beam transmission characteristics of elliptical aperture and axicon system are studied based on the Fresnel diffraction theory, complex Gaussian function expansion and stationary phase method of hard-edged aperture. The formula of non-diffracting optical fields after Gauss plane wave propagating through the axicon The beam transmission characteristics of elliptical aperture and axicon system are studied based on the Fresnel diffraction theory, complex Gaussian function expansion and stationary phase method of hard-edged aperture. The formula of non-diffracting optical fields after Gauss plane wave propagating through the axicon is deduced, the transverse intensity distributions of the beam in different propagation distances are numerical simulated and the experimental verification is also carried out. The intensity distributions in different propagation distances are captured by a charge coupled device (CCD) camera. The experimental results and numerical simulation all suggest that plane wave passing through a optical system with an elliptical aperture and axicon can obtain the qausi-non-diffracting beam which has similar characteristics to Mathieu beam. This result has guiding function in the application of optical nondestructive testing and barcode scanning..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 126001 (2015)
Quantum Optics
Nonlinear Circular States and Their Non-Classical Properties
Fang Xu, and Wang Zhongjie
In order to study the influence of nonlinearity and superposition on quantum state, by applying theoretical analysis and numerical computation, a new quantum state, namely nonlinear circular state, is studied. The nonclassical properties of the state are analyzed such as average photon number distribution, sub-Possion In order to study the influence of nonlinearity and superposition on quantum state, by applying theoretical analysis and numerical computation, a new quantum state, namely nonlinear circular state, is studied. The nonclassical properties of the state are analyzed such as average photon number distribution, sub-Possion distribution and squeezing effect, and its Wingner function is calculated. Through numerical analysis, the results show that with the increase of the Lamb- Dicke parameter and superposition number of quantum states, the average photon number of nonlinear circular state is increased and the sub- Poisson distribution and squeezing effect of the state are both weakened. The nonclassical properties of the state are very sensitive to nonlinear effects which are characterized by the Lamb- Dicke parameter and superposition number of quantum states..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 127001 (2015)
Remote Sensing and Sensors
Principle of Auto-Scanning Synthetic Aperture Imaging Ladar Using Hyperbolic Wavefront Difference
Liu Liren
A kind of auto-scanning down-looking synthetic aperture imaging ladar (SAIL) is proposed, which in construction uses two coaxial orthogonally polarized beams in transmitter and polarization interference based self-heterodyning detection in receiver and in principle adopts the wavefront transformation to generate illumiA kind of auto-scanning down-looking synthetic aperture imaging ladar (SAIL) is proposed, which in construction uses two coaxial orthogonally polarized beams in transmitter and polarization interference based self-heterodyning detection in receiver and in principle adopts the wavefront transformation to generate illumination wavefronts with a hyperbolic spatial phase difference. Therefore, the wavefront scanning from the relative movement of target produces automatically the necessary linear phase modulation in the orthogonal direction of travel, and the quadratic phase history in the travel direction as well. The image is reconstructed by virtue of the Fourier transform with the Doppler quadratic compensation in the orthogonal direction of travel and the conjugate quadratic phase matched filtering with the crossed coupling compensation in the travel direction. The system is very simple in structure. Optical modulator isn′ t used. The initial phase synchronization for linear phase modulations doesn′t exist. The time delay of target doesn′t exist, too. And the advantages of the original down-looking SAIL remains such as the availability of big receiving aperture and big optical footprint, and the capability of suppression of phase interferences from atmospheric turbulence and others. The suggested SAIL is of practical potentials to applying for spaceborne and airborne observation or inverse-SAIL radar under every workable distance and speed..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 128001 (2015)
Scattering
Effects of Charged Sandstorm on Electromagnetic Wave Propagation
Min Xing, Li Xingcai, Li Xinwan, and Ma Xin
Based on the polarization charge density and Rayleigh scattering theory, the impact of wind and sand electrostatic field on the optical properties of sand is discussed through numerical calculation and simulation. The results show that in considering the effects of sand electrostatic field, the sand scattering efficienBased on the polarization charge density and Rayleigh scattering theory, the impact of wind and sand electrostatic field on the optical properties of sand is discussed through numerical calculation and simulation. The results show that in considering the effects of sand electrostatic field, the sand scattering efficiency to electromagnetic waves firstly increases and then decreases with the charge distribution angle increasing, and the absorption efficiency to electromagnetic waves keeps a constant, but its magnitude is much larger than that of not considering the environmental electric field. In addition, the sandstorm attenuation to electromagnetic waves increases with the increase of particle concentration and humidity. Those results illustrate that it is necessary to consider the function of sandstorm electrostatic field in the remote sensing of sandstorm..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 129001 (2015)
Anomalous Diffraction Approximation for the Scattering Properties of Stratified Homogeneous Particles
Yu Xueping, Hu Yun′an, Liu Liang, Xie Yongxing, and Wang Yajiao
There are many kinds of suspended particles in natural environment, and research on scattering characteristics of particles has extensive application value. The existing theoretical calculation is complex, and it is often based on assuming a homogeneous composition sphere model without the difference of particle’s inteThere are many kinds of suspended particles in natural environment, and research on scattering characteristics of particles has extensive application value. The existing theoretical calculation is complex, and it is often based on assuming a homogeneous composition sphere model without the difference of particle’s internal composition structure. Through the analysis of calculation for extinction and absorption efficiency of two- layered homogeneous sphere model, the anomalous diffraction approximation method is extended to multilayered homogeneous particle model. The corresponding error comparison illustrates the usefulness of the method. The scattering properties of two- layered homogeneous particles with different internal and external sphere parameters and offcenter deviations are discussed by taking marine plankton as an example.The simulation results show that except for size and refractive index, particle heterogeneous structure also plays a role on the forward scattering. When the difference between inner and outer sphere parameters is large, it is necessary to consider the influence of structural factors on the scattering properties..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 129002 (2015)
Spectroscopy
Research on the Spectrum Signal Denoising Based on NLMS Filter Fluorescence Detecting Benzo (a) Pyrene
Wang Shutao, Zeng Qiuju, Wang Liyuan, and Liu Minghua
According to the characteristic that benzo (a) pyrene (bap) will fluoresce under the irradiation of light, the ultraviolet fluorescence is used to detect the bap concentration, builds the dectetion of bap concentration experiment system. In order to accurately detect the bap concentration, the data from the experiment According to the characteristic that benzo (a) pyrene (bap) will fluoresce under the irradiation of light, the ultraviolet fluorescence is used to detect the bap concentration, builds the dectetion of bap concentration experiment system. In order to accurately detect the bap concentration, the data from the experiment need remove noise with the filter contained in the experiment, to get the fluorescent signal effectively. The normalized least mean squared adaptive filter principle is applied to the noise spectral data processing, compared with the wavelet denoising effect, with Matlab to simulate out denoising effect, and analysis of the different denoising effect from different perspectives. After the contrast, using the minimum normalized adaptive filter can keep the non- stationary signal feature, and achieve more ideal denoising effect and better denoising performance. Hence, this method is suitable for the signal processing of fluorescence detection matter concentration..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 130001 (2015)
Characterization of Junction Temperature of GaN Blue LED with Optimum Spectral Bandwidth
Rao Feng, Zhu Xifang, Xu Ancheng, Chu Jing, and Zhang Yan
The optimum approach to determine junction temperature of GaN blue light emitting diode (LED) with spectral bandwidth is studied. The normalized spectral power distribution and junction temperature of ten GaN blue LEDs is measured at different drive current and heat sink temperature. The formulae for calculating junctiThe optimum approach to determine junction temperature of GaN blue light emitting diode (LED) with spectral bandwidth is studied. The normalized spectral power distribution and junction temperature of ten GaN blue LEDs is measured at different drive current and heat sink temperature. The formulae for calculating junction temperature with Dln are obtained from the least-square fitting. Difference between the values by the established method and the forward voltage method is analyzed. The optimum n, which yields the least error, is obtained. It is shown that the spectral bandwidth Dln with different n can be used to determine junction temperature, and the error initially decreases with the decreasing n, and then increases. The optimum n depends on the accuracy of spectrometer, it is 0.2 or 0.3 when Hass2000 spectrometer is used. This research is very important to improve the measurement accuracy of GaN-type LED junction temperature..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 130002 (2015)
Application of Raman Spectroscopy in Certification of Chicken-Blood Stones
Han Xiaozhen, Guo Zhengye, Kang Yan, Liu Xueliang, and Guo Shouguo
Six pieces of chicken-blood stones from different origins are tested and analyzed with a laser micro-Raman spectrometer. Characteristic Raman spectra of the 6 stone samples are obtained and helpful for the nondestructive identification of chicken-blood stones.“Blood”of the 3 pieces of chicken-blood stones from Yuyan MoSix pieces of chicken-blood stones from different origins are tested and analyzed with a laser micro-Raman spectrometer. Characteristic Raman spectra of the 6 stone samples are obtained and helpful for the nondestructive identification of chicken-blood stones.“Blood”of the 3 pieces of chicken-blood stones from Yuyan Mountain, Changhua Town, Lin′an, is cinnabar (HgS). The main mineral composition in Di of the 3 samples is different, which probably contains dickite, kaolinite, alunite, quartz or other minerals.“Blood”of the sample from Zixi is hematite (α-Fe2O3) and its Di is high purity dickite.“Blood”of the sample from Guilin is hematite and its Di is quartz.“Blood”of the sample from Guizhou is cinnabar and its Di is carbonate mineral. The data tested by X-ray powder diffraction are consistent with that by laser micro-Raman spectroscopy..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 35, Issue 1, 130003 (2015)
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