Contents
2010
Volume: 30 Issue 11
51 Article(s)
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Research Article
Atmospheric Optics and Oceanic Optics
Aberrations Detection Using Holographic Modal Wavefront Sensor
Liu Changhai, Jiang Zongfu, Huang Shengyang, and Ma Haotong
Detailed analysis is carried out upon the holographic modal wavefront sensor (HMWFS) based on the scalar diffraction theory. An analytical expression of intensity distribution of the diffraction field on the detector plane of the HMWFS is presented, which results in the unification with the theory of mode-biased wavefrDetailed analysis is carried out upon the holographic modal wavefront sensor (HMWFS) based on the scalar diffraction theory. An analytical expression of intensity distribution of the diffraction field on the detector plane of the HMWFS is presented, which results in the unification with the theory of mode-biased wavefront sensor. For the sake of simplicity in numerical simulation of the HMWFS, an equivalent model of the HMWFS is proposed, in which two tilt conjugate plane waves are chosen to replace the tilt convergent spherical waves as the reference waves in recording holograms, and place a convergent lens in close proximity to the rear surface of holographic element. Then the operation principle of the HMWFS is validaled by numerical simulations employing the equivalent model. The results demonstrates the high sensitivity and fast sensing speed of the HMWFS..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3069 (2010)
Real-Time Parallel Wavefront Processor for Adaptive Optics Based on Stochastic Parallel-Gradient-Descent Algorithm
Wang Caixia, Li Mei, Li Xinyang, and Ye Hongwei
The adaptive optical system based on stochastic parallel gradient descent algorithm (SPGD) compensates wavefront aberration by direct optimization of a system performance metric. The convergence rate is the key factor that limits the SPGD algorithm application in practical adaptive optics system. On the basis of analysThe adaptive optical system based on stochastic parallel gradient descent algorithm (SPGD) compensates wavefront aberration by direct optimization of a system performance metric. The convergence rate is the key factor that limits the SPGD algorithm application in practical adaptive optics system. On the basis of analysis of SPGD algorithm in which the concurrency is embedded, a pipeline single instruction and multipe data (SIMD) architecture parallel real-time wavefront processor is deslgned and implementd in which field-programmable gate array (FPGA) and digital signal processing (DSP) are introduced. The optimal mapping of the control algorithm from representative layer to the architecture is realized. The wavefront processor is applied to a laser beam cleanup adaptive optical system to control the deformable mirror and fast steering mirror. The experimental results show that real-time parallel wavefront processor based on SPGD algorithm can compensate the wavefront aberration and tilt excursion of the laser beam involved effectively and that the convergence rate is enhanced enormously..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3076 (2010)
An Automatic Defocus Compensation Method for Human Eye Hartmann-Shark Wave-Front Aberrometer
Bao Hua, Rao Changhui, Zhang Yudong, Dai Yun, Yu Xiang, and Rao Xunjun
An automatic defocus compensation method for human eye Hartmann-Shark (HS) wave-front aberrometer is proposed. According to the analysis of different geometric features of HS light spots during focalizing process, estimation algorithm is constructed to remove large-scale defocus amount, and then the residual high-orderAn automatic defocus compensation method for human eye Hartmann-Shark (HS) wave-front aberrometer is proposed. According to the analysis of different geometric features of HS light spots during focalizing process, estimation algorithm is constructed to remove large-scale defocus amount, and then the residual high-order ocular aberrations can be measured by aberrometer successfully. Experimental results proved that the method has good robustness to control noise and can achieve accurate automatic defocus compensation from ocular aberrations, which is very useful method to human eye HS wave-front aberrometer..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3082 (2010)
Study on Partitioning of Phytoplankton Absorption Coefficient from Total Spectral Absorption in Taihu Lake
Le Chengfeng, Li Yunmei, Zha Yong, Yin Bin, and Zhang Hong
A method for partitioning phytoplankton absorption coefficient is developed in this study using in situ sampling dataset collected from Taihu Lake. Because the absorption of non-algal particles and colored dissolved organic matter(CDOM) has similar optical properties, their absorption coefficients are combined to paramA method for partitioning phytoplankton absorption coefficient is developed in this study using in situ sampling dataset collected from Taihu Lake. Because the absorption of non-algal particles and colored dissolved organic matter(CDOM) has similar optical properties, their absorption coefficients are combined to parameterize by the method. The ratio of phytoplankton absorption coefficient at 580 nm and 692 nm is also used in the method because of its consistence. The performance of the method is assessed both in magnitude and spectral characteristic. The results indicate that the absorption of phytoplankton can be well divided from the total absorption. The method has good performance at band 440, 550 and 675 nm in phytoplankton absorption partition, and the mean relative error is less than 10% at band 675 nm. The phytoplankton absorption spectra partitioned from total spectral absorption keeps its inherent character, and fits with measured ones perfectly, the mean similarity coefficient (SC) of them can reach 0.97..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3090 (2010)
Cloud Detection and Parameter Retrieval Based on Improved Differential Zero-Crossing Method for Mie Lidar
Mao Feiyue, Gong Wei, Li Jun, and Zhang Jinye
Mie lidar is widely used in the spatial distribution detection of atmospheric aerosol and cloud, but there are some difficulties in cloud detection from return signal automatically and accurately. The differential zero-crossing method is one of the dominant methods, but it has a disadvantage of big uncertainty when theMie lidar is widely used in the spatial distribution detection of atmospheric aerosol and cloud, but there are some difficulties in cloud detection from return signal automatically and accurately. The differential zero-crossing method is one of the dominant methods, but it has a disadvantage of big uncertainty when the signal-to-noise ratio is low. The differential zero-crossing method is improved based on the feature of the return signal of LiDAR. Namely the former and latter cloud information and signal intensity are referred to in the improved method, so obvious errors are efficiently avoided. Finally, the cloud extinction coefficient and optical thickness are retrieved based on the cloud detection result. The variations feature of the optical properties is represented objective. Further more, precise and automatic lidar cloud detection and coefficient retrieval are achieved preliminarily..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3097 (2010)
Propagation Properties of Annular Beams in Atmospheric Turbulence
Zhang Shuai, Qiao Na, Zhang Bin, and Dan Youquan
Based on the extended Huygens-Fresnel principle and the Rytov approximate theory, analytical expressions for intensity distribution of annular beams through turbulent atmosphere have been derived. Then, according to the definition of the second-order moments of intensity, an analytical formula of M2 factor for annular Based on the extended Huygens-Fresnel principle and the Rytov approximate theory, analytical expressions for intensity distribution of annular beams through turbulent atmosphere have been derived. Then, according to the definition of the second-order moments of intensity, an analytical formula of M2 factor for annular beams propagating in atmospheric turbulence has been derived. Finally, the propagation properties and the changes of beam quality of annular beams through the turbulent atmosphere have been discussed in detail. The results indicate that the propagation and transformation of the annular beams through the turbulent atmosphere have been directly affected by the intensity of the turbulence. Due to the effect of the turbulence, the annular beams turn from completely coherent beams into partially coherent beams in the propagation process. The M2 factor of the annular beams depends on the obstruction ratio, the turbulence intensity, the beam wavelength and the propagation distance. By using a suitable choice of the beam parameters, such as the obstruction ratio and the wavelength of annular beams, the beam quality of annular beams in atmospheric turbulence could be effectively controlled..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3103 (2010)
Study of Irradiance Fluctuations for Laser Beam Propagation in Atmosphere
Jing Xu, Wu Yi, Hou Zaihong, Qin Laian, and Lu Qian
Property of intensity fluctuation over different receiving aperture for collimated beam propagation in atmosphere is got by experimental method. Using normalized variance of intensity fluctuation and aperture averaging factor the property of intensity fluctuation over different receiving aperture is described and the pProperty of intensity fluctuation over different receiving aperture for collimated beam propagation in atmosphere is got by experimental method. Using normalized variance of intensity fluctuation and aperture averaging factor the property of intensity fluctuation over different receiving aperture is described and the probability distribution of normalized variance of intensity fluctuation measured with different aperture sizes under different atmosphere conditions is compared. Experimental results show that while turbulent level becomes larger, the receiving area corresponding to aperture averaging effect appears obviously becomes smaller. The probability distribution corresponding different receiving area can be represented by Log-Gauss distribution. Skewness, kurtosis and the feature of Gauss fitted data calculated under experimental conditions are compared. The similarities and differences between the relative intensity fluctuation variance probability distribution of the continuous-wave laser and one of pulsed laser are also compared..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3110 (2010)
Effects of Changing Threshold on Detection Probability of Scannerless Range-Gated Lidar
Wu Long, Zhao Yuan, Jin Chenfei, Zhang Yu, and Sun Xiudong
The converted number of photoelectrons after the photocathode of scannerless imaging lidar meet the Poisson statistical distribution. The calculation for judging threshold of lidar system is proposed according to maximum likelihood estimation. Taking a typical scannerless range-gated imaging lidar as the case, an approThe converted number of photoelectrons after the photocathode of scannerless imaging lidar meet the Poisson statistical distribution. The calculation for judging threshold of lidar system is proposed according to maximum likelihood estimation. Taking a typical scannerless range-gated imaging lidar as the case, an approach to approximately calculate detection probability, false-alarm probability and dropouts probability is presented which is proved by Monte-Carlo simulation. The effect of system threshold on detection probability is analyzed. A proposal that increases the detection probabilities when threshold changes with signal and noise is raised. Under the hardware limitation of lidar system, as the detection requests are satisfied, reducing the detection range and number of detector pixels mostly, increasing arrived signal photons from the target, determining the threshold by maximum likelihood estimotion, the detection probability of the system is improved..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3117 (2010)
Atomic and Molecular Physics
Dressed-Atom Spectra of Cold Cesium Atoms Trapped in a Magneto-Optical trap
Yang Baodong, Liang Qiangbing, Yang Jianfeng, Zhang Tiancai, and Wang Junmin
Due to the strong cooling laser, the cesium cold atoms trapped in a magneto-optical trap are dressed. The dressed splitting was observed arising from cooling laser for the ground state 6S1/2 F=4 and excited state 6P3/2 F′=5 using the probe laser with the wavelengths of 852.3 nm (corresponding to the transitions of 6S1/Due to the strong cooling laser, the cesium cold atoms trapped in a magneto-optical trap are dressed. The dressed splitting was observed arising from cooling laser for the ground state 6S1/2 F=4 and excited state 6P3/2 F′=5 using the probe laser with the wavelengths of 852.3 nm (corresponding to the transitions of 6S1/2 F=4→6P3/2 F′=3 and 6S1/2 F=4→6P3/2 F′=4 of cesium atom) and 794.6 nm (corresponding to the transition of 6P3/2 F′=5 and 8S1/2 F″=4 of cesium atom), respectively, and their spectral properties were analysed. The results show that the dressed splitting for the ground state 6S1/2 F=4 is the same with that for the excited state 6P3/2 F′=5 for the same intensity and detuning of cooling laser, which is consistent with the prediction based on the dressed state theory..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3124 (2010)
Diffraction and Gratings
Fabrication and Experimental Investigation of Diffraction Characteristics for a Pitch-Tunable Grating Based on SOG Process
Yan Bin, Yuan Weizheng, Yu Yiting, Qiao Dayong, Sun Ruikang, and Li Taiping
Based on the micro-opto-electro-mechanical systems (MOEMS) technology, a new micro programmable grating with tunable pitch is designed and fabricated by using silicon-on-glass (SOG) processing. The pitch-tunable grating has prominent advantages over the conventional optical devices such as simple operation, continuous Based on the micro-opto-electro-mechanical systems (MOEMS) technology, a new micro programmable grating with tunable pitch is designed and fabricated by using silicon-on-glass (SOG) processing. The pitch-tunable grating has prominent advantages over the conventional optical devices such as simple operation, continuous adjusting, and wide modulation. The change of the grating pitch results in the change of monochromatic diffraction angle and chromatic wavelength. Then two experimental setups for practically measuring the change of monochromatic diffraction angle and chromatic wavelength are designed and established, respectively. The characteristics of the grating according to the designed structural dimensions agree very well with the experimental results, which proves that the grating has good modulation performances. This work lays a good foundation for the future research in micro spectrometers and optical communication and provides valuable technical references..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3128 (2010)
Research of Optimization Design of Groove Diffraction Grating Profile Parameters
Fan Shuwei, Zhou Qinghua, and Li Hong
The optimization design of structural parameters for diffraction grating is researched by combining the diffraction grating vector theory and the global optimization theory. Rigorous coupled wave analysis (RCWA) is used to analyze the grating diffraction efficiency properties, then the global optimization genetic algorThe optimization design of structural parameters for diffraction grating is researched by combining the diffraction grating vector theory and the global optimization theory. Rigorous coupled wave analysis (RCWA) is used to analyze the grating diffraction efficiency properties, then the global optimization genetic algorithm (GA) model in the design of diffraction grating is established. The optimized structural parameters of several typical gratings including double-blazed grating in arbitrary incident angle are given. There are no special requirements for initial design and optimal groove diffraction grating structure can be obtained quickly. Optimized diffraction efficiency can reach more than 90%. Double-blazed grating can also get very high diffraction efficiency in the whole band after the optimization. The global engineering design optmization algorithm provides theoretical guidance for grating fabrication and also provides a feasible method for the inverse problem of grating design..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3133 (2010)
Fiber Optics and Optical Communications
A Local Oscillator-Free Frequency Mixing Based on FP-LD Injection
Wu Bo, Yu Jinlong, Zhang Zusong, Han Bingchen, Luo Jun, Guo Jingzhong, Zhang Xiaoyuan, Wang Ju, and Yang Enze
a novel local oscillator (LO)-free frequency mixing based on FP-LD injection is proposed. The sideband of four wave mixing (FWM) between external injection light and one longitudinal mode of FP-LD generates sideband locking longitudinal mode which then produces the radio-frequency (RF) signal. By adjusting the intensita novel local oscillator (LO)-free frequency mixing based on FP-LD injection is proposed. The sideband of four wave mixing (FWM) between external injection light and one longitudinal mode of FP-LD generates sideband locking longitudinal mode which then produces the radio-frequency (RF) signal. By adjusting the intensity and polarization of injection signal, different mixing frequency is obtained and the different side-mode suppression ratio is analyzed theoretically. Subcarrier of 16.2, 10.0, 18.2 and 20.0 GHz is obtained from 2.7, 2.5 and 1.25 Gb/s NRZ signal injection into FP-LD respectively, in which the single sideband phase noise of -81.2 and -87.7 dBc/Hz at 10 kHz frequency deviation of 16.2 GHz is measured..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3140 (2010)
Research of Ultraviolet Non-Line-of-Sight Single Scattering Link Model
He Hua, Ke Xizheng, and Zhao Taifei
In order to profoundly study the mechanism of ultraviolet non-line-of-sight scattering transmission, based on ellipsoidal coordinate, the scattering process of photons from transmitter to receiver and energy change in the process are analysed; Furthermore, the study of the effective scattering volume integral is mainlyIn order to profoundly study the mechanism of ultraviolet non-line-of-sight scattering transmission, based on ellipsoidal coordinate, the scattering process of photons from transmitter to receiver and energy change in the process are analysed; Furthermore, the study of the effective scattering volume integral is mainly inresthgated due to the dose relation with the ultraviolet communication, and the three groups of integral limits which determine the volume integral is analysed and calculated. Integral limit formulas of each group are achieved. The results give the integrated explaination and exact quantification of ultraviolet communication mechanism and receiving power. It builds a solid foundation for the ultraviolet network and the future study..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3148 (2010)
Evolution of Polarized State in Linearly Birefringent Magneto-Optic Fiber Bragg Gratings
Li Chongzhen, and Wu Baojian
According to the perturbation theory for guided optical waves, coupled-mode equations in linearly birefringent magneto-optic fiber Bragg gratings (LB-MFBGs) as well as its analytical solution are presented. Dependence of optical polarization state in the LB-MFBGs on linear birefringence and magnetically circular birefrAccording to the perturbation theory for guided optical waves, coupled-mode equations in linearly birefringent magneto-optic fiber Bragg gratings (LB-MFBGs) as well as its analytical solution are presented. Dependence of optical polarization state in the LB-MFBGs on linear birefringence and magnetically circular birefringence is in detail investigated by means of normalized Stokes parameters. It is shown that, in the LB-MFBGs there exist two eigenstates of polarization (left-handed and right-handed elliptically polarized light), and the birefringence effects only change the ellipticity, instead of the azimuth of principal axis. By changing the relative magnitude of the linear and circular birefringence, the output polarization states could be controlled, which is helpful for the potential applications of the LB-MFBGs in optical fiber communication and sensing..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3153 (2010)
Numerical Dispersion Compensation for Polarization-Mode Coupling Distributed Fiber Sensors
Chen Xinwei, Zhang Hongxia, Jia Dagong, Liu Tiegen, and Zhang Yimo
The influence of birefringence dispersion on the measurement sensitivity of polarization-mode coupling white light distributed polarization maintaining fiber sensor is analyzed and experimentally investigated. A numerical dispersion compensation algorithm is presented to calculate the coupling strength. The algorithm bThe influence of birefringence dispersion on the measurement sensitivity of polarization-mode coupling white light distributed polarization maintaining fiber sensor is analyzed and experimentally investigated. A numerical dispersion compensation algorithm is presented to calculate the coupling strength. The algorithm based on the interferogram envelope area is a constant though there exists the influence of birefringence dispersion on the fiber sensor and the algorithm ignores the optical intensity loss in propagation along the fiber. The interferogram envelope area can be obtained by the Hilbert envelope retrieval and nonlinear least square fitting, and then the polarization coupling strength can be obtained. The experimental result shows that the algorithm has a high accuracy, and the absolute deviation is less than 0.63 dB for short fibers..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3159 (2010)
Image Processing
Target Initialization Based on Random Ferns during Electro-Optical Imaging Terminal Guidance
Chen Bing, Zhao Yigong, and Li Xin
In order to solve the problems of image differences in scale, rotation, grayscale and 3D viewing angle, and achieve adaptive target initialization during electro-optical imaging terminal guidance, a new scene matching framework based on random Ferns classifier was constructed. The process of realizing the method includIn order to solve the problems of image differences in scale, rotation, grayscale and 3D viewing angle, and achieve adaptive target initialization during electro-optical imaging terminal guidance, a new scene matching framework based on random Ferns classifier was constructed. The process of realizing the method includes classifier off-line training which yields fast run-time performance was performed. Candidate match regions between reference image and run-time image were found by the classifier. Scale invariant feature transform (SIFT) descriptors of corresponding regions in each candidate matches were computed and false matches feature pairs rejecting was performed based on Mahalanobis distance criterion. Epipolar geometry of the two images was estimated by applying PROSAC to the central locations of the corresponding regions in the final matches. Target location and size in run-time image were computed based on the epipolar geometry. Simulation results show that the proposed method provides robust target initialization during electro-optical imaging terminal guidance and is more stable than original Ferns methods under severe conditions..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3164 (2010)
Imaging Systems
Automatic Test System for Static Transfer Function of the Big Visual Field Time-Delayed integration Charge Coupled device Camera
Li Guoning, Liu Yanyan, Jin Longxu, and Ren Jianyue
In order to solve the problems that the coverage rate of visual field is not high and that the test precision and efficiency are lower in the course of testing static transfer function (TF) of the big visual field time-delayed integration (TDI) charge coupled device (CCD) camera, a kind of automatic test system for staIn order to solve the problems that the coverage rate of visual field is not high and that the test precision and efficiency are lower in the course of testing static transfer function (TF) of the big visual field time-delayed integration (TDI) charge coupled device (CCD) camera, a kind of automatic test system for static TF is designed. First, taking TDI CCD as unit, entire visual field of camera is divided. Then revolving stage is moved and the location relation of TDI CCD is adjusted corresponding visual field and the parallel optical pipe. Computer receives the target mark image acquired by camera, analyses target image feature and draws TF change curves. From these curves, the best TF test points of each slice of TDI CCD corresponding visual field are defined and location information storehouse is established. Then according to location information, the revolving stage is automatically moved to the best TF test point of each slice of TDI CCD corresponding visual field. Beginning from the first pixel of each slice of TDI CCD, it is moved to the last pixel gradually with regular step. When it is moving, it tests TF. Finally, static TF curve of entire visual field of the big visual field TDI CCD camera is drawn. Experimental results indicate that the test system of static TF has covered the entire visual field of camera. The tested average of static TF is 0.2965. Compared with the previous test method, the average of static TF of entire visual field has raised 0.02. At the same time, the test system has also raised test efficiency and test precision of the static TF..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3171 (2010)
Temporal Model of Underwater Laser Range-Gated Imaging and Pulse Stretching
Huang Youwei, Wang Xia, Jin Weiqi, Ding Kun, Li Hailan, and Liu Jing
On the basis of range-gated technology, the temporal relation between laser pulse propagation and gated reception was analyzed, and an integrated underwater range-gated temporal model was proposed. The model was validated via specially designed experiments which were carried out on a home-built underwater laser range-gOn the basis of range-gated technology, the temporal relation between laser pulse propagation and gated reception was analyzed, and an integrated underwater range-gated temporal model was proposed. The model was validated via specially designed experiments which were carried out on a home-built underwater laser range-gated platform. The good agreements between the experiments and simulations confirm that the model can predict the variations of image contrasts versus delay time, and can be applied to the performance prediction and optimal design of real systems. Furthermore, the effects of the various parameters on the image contrasts versus delay time were discussed, and the measurement of pulse temporal stretching based directly on range-gated technology was also introduced..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3177 (2010)
Instrumentation, Measurement and Metrology
Characteristics of Transmission Fluctuation Frequency Spectrum with Band-Pass Filters
Xu Yamin, Shen Jianqi, and Cai Xiaoshu
The transmission fluctuation spectrometry (TFS) is a new method based on the spectral characteristics of the transmission fluctuation spectra, which is developed recently for real-time, online/inline particle analysis in two-phase flow. Both the particle size distribution and concentration can be measured simultaneouslThe transmission fluctuation spectrometry (TFS) is a new method based on the spectral characteristics of the transmission fluctuation spectra, which is developed recently for real-time, online/inline particle analysis in two-phase flow. Both the particle size distribution and concentration can be measured simultaneously. The characteristics of the transmission fluctuation spectra with the 1 st order band-pass filters is presented detailedly. The effects of the filter band width parameter on the spectrum and on the inversion results are analyzed together with the effects of the dimensionless beam diameter (beam-to-particle diameter ratio). Numerical calculation and experiments show that a small value of band width parameter can improve the resolution of measurements but reduce the strength of the spectrum and hence bring errors into the results. On the contrary, a big value of band width parameter is beneficial to obtain a strong spectrum but lead to low resolution of measurement..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3184 (2010)
A 3-D Measurement Method with Orthogonal Composite Light Based on Fringe Contrast and Background Calibration
He Yuhang, Cao Yiping, and Zhai Aiping
A three dimensional(3-D) measurement method with orthogonal composite grating based on fringe contrast and background calibration is presented. We get the phase-shifted sine fringes from the composite grating image captured on the reference plane, and the zeroth order spectrum and first order spectrum of the phase-shifA three dimensional(3-D) measurement method with orthogonal composite grating based on fringe contrast and background calibration is presented. We get the phase-shifted sine fringes from the composite grating image captured on the reference plane, and the zeroth order spectrum and first order spectrum of the phase-shifting sinusoidal fringes can be obtained by filtering in spatial frequency domain, then the ratio coefficients of contrast and background between the sinusoidal fringes can be calculated out. When an object is measured, the contrast and background of the demodulated deformed fringes can be calibrated by these ratio coefficients, and new 3-D measurement mathematical model is set up. Experiments prove that the new method can effectively reduce phase error, and improve measurement accuracy..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3191 (2010)
Best-Fit Spheric Surface Definition Based on Slope Asphericity for Aspheric Surface
Xie Feng, Hao Qun, and Zhu Qiudong
In order to describe the difference between aspheric surface and sphere accurately and fit the aspheric surface measurement techniques, a best-fit spheric sureace based on slope asphericity is proposed. First the min-max slope asphericity associated to manufacturing difficulty of computer-generated hologram and aspheriIn order to describe the difference between aspheric surface and sphere accurately and fit the aspheric surface measurement techniques, a best-fit spheric sureace based on slope asphericity is proposed. First the min-max slope asphericity associated to manufacturing difficulty of computer-generated hologram and aspheric surface measurement difficulty was analyzed, when the min-max slope asphericity is beneficial to reduce the measurement error of laser deflectometry. Then a calculation model of best-fit sphere is proposed, and the distribution of slope asphericity corresponding to different comparing spheric surfaces, the best-fit spheric sureace of different aspheric surfaces, the effects of aspheric surface parameters to calculation result, and the best-fit spheric sureace of different asphericity definitions are analyzed. The results indicate that the center of best-fit spheres corresponding to different aspheric surfaces is the cross point between the normal of 0.85～0.87 aperture of aspheric surface and the optical axis, thereby the calculation process is optimized, and the best-fit sphere based on slope asphericity is different from prior methods, thus it fits aspheric surface measurement..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3197 (2010)
Railway Geometric Parameters Measurement System Based on Videometrics
Fu Sihua, Yu Qifeng, Wang Mingzhi, Jiang Heping, and Xu Bohong
A railway geometry parameters measurement system on the basis of the vidometrics theory is designed. The system consists of two components a measurement bogie and a target bogie. When the measurement procedure is preceded, the target bogie moves towards the measurement bogie along a rail. The camera on the measurement A railway geometry parameters measurement system on the basis of the vidometrics theory is designed. The system consists of two components a measurement bogie and a target bogie. When the measurement procedure is preceded, the target bogie moves towards the measurement bogie along a rail. The camera on the measurement bogie grabs the motion image sequences of the infrared cooperative markers on the target bogie in a real-time manner. At the same time, the software installed in the industrial computer on the measurement bogie locates the sub-pixel positions that the cooperative markers project into the image sequences, and it drives the motorized lens to the correct imaging state according to the distance between the markers and the image definition. Consequently, the viewing field of the camera holds the line and the images of the markers remain definite. Finally, the railway geometric parameters are synthesized from the positions of the markers on the basis of corresponding mathematical model. Both the static and the field experimental results prove that this videometrics measurement system can satisfy the requirement of the high-precision measurement for the rail geometric parameters..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3203 (2010)
Lasers and Laser Optics
Coherent Beam Combination of Passive Phase Locking of an Array of Three Fiber Lasers in One Dimension by a Ring Cavity
Li Zhen, Zhou Jun, He Bing, Xue Yuhao, Qi Yunfeng, Liu Chi, and Lou Qihong
Technique for passive phase locking of fiber lasers by an all-optical feedback loop is studied theoretically and experimentally. The experimental setup of coherent beam combination of three fiber lasers in one dimension is built, and phase-locking of three fiber lasers is achieved and stable interference patterns are oTechnique for passive phase locking of fiber lasers by an all-optical feedback loop is studied theoretically and experimentally. The experimental setup of coherent beam combination of three fiber lasers in one dimension is built, and phase-locking of three fiber lasers is achieved and stable interference patterns are observed. The influence of duty ratios on the interference patterns in the far field is studied. Main factors that affect the cavity loss are analyzed. Random peaks corresponding to different wavelengths are found in the spectrum of coherent output laser. By using a narrow bandwidth filter, the spectral range of coherent output laser can be restricted. However, the phenomenon mentioned above still exists. And theoretical analysis is given to explain these random wavelengths existing in this kind of technique for passive phase-locking..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3209 (2010)
Studies on Mode-Locking Features of Sub-10-fs TiSapphire Oscillator with Domestic Chirped Mirrors for Intra-Cavity Dispersion Compensation
Song Youjian, Hu Minglie, Wang Yanzhi, Shao Jianda, Jin Yunxia, Chai Lu, Fan Zhengxiu, and Wang Qingyue
A Tisapphire laser with domestic un-paired chirped mirror for intracavity dispersion compensation is reported. Ultrashort optical pulses with mode-locked pulse output power of 120 mW are generated at a repetition rate of 93.7 MHz. The pulse duration as short as 9.7 fs is achieved after extracavity dispersion compensatiA Tisapphire laser with domestic un-paired chirped mirror for intracavity dispersion compensation is reported. Ultrashort optical pulses with mode-locked pulse output power of 120 mW are generated at a repetition rate of 93.7 MHz. The pulse duration as short as 9.7 fs is achieved after extracavity dispersion compensation. The spectrum and pulse autocorrelation trace evolution with intracavity dispersion are investigated by adjusting the insertion of intracavity wedge. A numerical model of the Tisapphire laser is also built based on the split-step Fourier method for solving nonlinear Schrdinger equation. The parameters used in the simulation are the same as in experiment. 10 order of Taylor series are used for modeling oscillation of the dispersion curve of chirped mirror. The mode-locking dynamics in the vicinity of zero cavity dispersion is achieved, and the restriction of higher-order dispersion on pulse duration compressing is also analyzed..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3215 (2010)
Multimode Polymeric Optical Power Splitter Based on an Asymmetrical Structure Using Laser Direct Writing
Li Shu, Zhuge Qunbi, Lin Qiao, and Wu Xingkun
A 1×8 power splitter made of UV curable optical epoxy was proposed and fabricated. A novel asymmetrical structure was utilized in power splitting scheme to enable a uniform distribution of energy among all branches. By the use of laser direct writing process and high precision translation stages, the prototyping pA 1×8 power splitter made of UV curable optical epoxy was proposed and fabricated. A novel asymmetrical structure was utilized in power splitting scheme to enable a uniform distribution of energy among all branches. By the use of laser direct writing process and high precision translation stages, the prototyping process was completed within a short fabrication phase of 5 min. Power splitting test was made and power from output ports were analyzed. The splitter has a nearly-equal output for all channels except for one with a 4% fluctuation. The asymmetric design and mask-less fabrication make it possible to realize an effective and high-yield production of this device..
Acta Optica Sinica
- Publication Date: Aug. 13, 2021
- Vol. 30, Issue 11, 3221 (2010)
A Novel High-Precision Laser Accelerometer
Long Xingwu, Xiao Guangzong, and Zhang Bin
Based on gas sylphon, a novel dual-frequency laser accelerometer with double Y-shaped cavity is proposed. The static principle and the structure of the accelerometer are introduced. The influence of different factors on its resolution and their influencing mechanism are analyzed. As the first step sensing unit, the gasBased on gas sylphon, a novel dual-frequency laser accelerometer with double Y-shaped cavity is proposed. The static principle and the structure of the accelerometer are introduced. The influence of different factors on its resolution and their influencing mechanism are analyzed. As the first step sensing unit, the gas sylphon is used to translate the acceleration signal to the refractivity variation of the gas in it. The acceleration was measured in the form of the beat frequency of the dual-frequency laser in the end. The structure of optical module and physical property of the accelerometer are more stable due to this kind of ingenious design which also affords facilities for optimizing the parameters of the elastic sensing element. It becomes feasible to separate the signal from the noise because they affect the beat frequency through different ways. The original double Y-shaped cavity structure restrain the influence of the temperature noise to a great extent because of the first differential s and p light and the second differential of the symmetric double Y-shaped lasers. Theoretical analysis shows that the scale factor of the accelerometer is 1.19×108 Hz/(m/s2) and its resolution is 1.15×10-6 g..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3227 (2010)
Path Length Control for Nonplanar Four-Mode Differential Laser Gyro with Hill-Climbing Method
Wang Zhiguo, Long Xingwu, Wang Fei, and Luo Hui
In order to solve the problem that the frequency stabilization system with light intensity comparison is subject to the parameters of optoelectronic components, a frequency stabilization circuit with small dithering was designed for nonplanar four-mode differential laser gyro. The beat wave amplitude in clockwise (or aIn order to solve the problem that the frequency stabilization system with light intensity comparison is subject to the parameters of optoelectronic components, a frequency stabilization circuit with small dithering was designed for nonplanar four-mode differential laser gyro. The beat wave amplitude in clockwise (or anticlockwise) light of four-mode differential laser gyro was amplified and detected, and then sampled to a digital signal processor (DSP) via analog to digital converter. Small dithering method could be used to stabilize the frequency of four-mode differential laser gyro under the condition that the beat wave amplitude reaches maximum when the gyro operates steadily. A digital system for frequency stabilization was designed with the DSP. Precision of frequency stabilization was 2×10-9 for 1 s sampling. What′s more important is that frequency stabilization point was immune to variations of parameters of optoelectronic components. The frequency stabilization circuit is precise and universal, so it is of some significance to improvement of capability over severe environment of four-mode differential laser gyro..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3233 (2010)
Materials
Poly (Ethylene Terephthalate) Electronic Structural and Optical Propertie from First Principles Calculations
Lin Jiaqi, Ni Haifang, Wang Chen, and Lei Qingquan
The electronic structural and optical properties of Poly (ethylene terephthalate) (PET) are studied based on first principle method of density functional theory. It shows that molecules orbit contribution of PET are derived from carbon 2p orbital and oxygen 2p orbital, respectively. However, the band gap from the energThe electronic structural and optical properties of Poly (ethylene terephthalate) (PET) are studied based on first principle method of density functional theory. It shows that molecules orbit contribution of PET are derived from carbon 2p orbital and oxygen 2p orbital, respectively. However, the band gap from the energy band structure is much smaller than that of the experimental value. For the highest occupied molecular orbital, the charge density is mainly distributed in the both sides of the benzene ring . However, for the lowest unoccupied molecular orbital, the charge density is mainly distributed on the benzene ring. The band gap calculated from the absorption edge of absorption spectra is in agreement with the result of the energy band structure. Furthermore, the relationship between the formation of dielectric function peaks and other spectral characteristics is interpreted..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3239 (2010)
Correction to Transmission Coefficient of p Polarized light in Layered Media
Hong Xiaogang, Xu Wendong, Zhao Chengqiang, and Tang Xiaodong
The computing formula of the electric field strength transmission coefficient of p polarized light in layered media is obtained by theoretical computation, and verified by finite difference time domain(FDTD) method. This formula is similar with that of the traditional transmission coefficient of p polarized light in laThe computing formula of the electric field strength transmission coefficient of p polarized light in layered media is obtained by theoretical computation, and verified by finite difference time domain(FDTD) method. This formula is similar with that of the traditional transmission coefficient of p polarized light in layered media computed by characteristic matrix method. The difference is that when the total internal reflection (TIR) occurs, a TIR correction factor arises. Furthermore, a two layer TIR structure and a surface plasmon resonance (SPR) film structure are simulated by FDTD method, and the results are in good agreement with those of the correction formula. This correction formula is a perfection to the propagation of electromagnetic wave in layered media, and an amendment to some influential references about the description of the field enhancement factor. It also has reference value for the researches on SPR and the evanescent field..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3244 (2010)
Growth of Near-Stoichiometric Lithium Tantalate and its Periodical Polarization
Jia Baoshen, and Zhao Yequan
Near-stoichiometric lithium tantalate crystal has been grown from off-stoichiometric melt by adding K2O flux. The grown crystals were free from cracks and twins. The Curie temperature of the grown crystal was (673±0.4) ℃. A PI polyimide photoresist grating with duty cycle 60% was deposited on +Z surface of the wafNear-stoichiometric lithium tantalate crystal has been grown from off-stoichiometric melt by adding K2O flux. The grown crystals were free from cracks and twins. The Curie temperature of the grown crystal was (673±0.4) ℃. A PI polyimide photoresist grating with duty cycle 60% was deposited on +Z surface of the wafer and LiCl saturated solution was used as liquid electrode. Homogenous periodically poled near-stoichiometric lithium tantalate (SLT) wafer with 0.5 mm thickness was fabricated by means of auto control poling technique. The duty cycle of the inverted domain was close to 50%. Optical experiment was done which the 1064 nm Nd+3YVO4 laser was used as the pump source..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3249 (2010)
Medical Optics and Biotechnology
Research on Systematic Evaluation Method for Light Hazard of Optical Apparatus in Ocular Optical Path
Jia Xiaohang, Wang Jingtao, Wang Yuanfu, and Shen Ye
Based on light radiation hazard algorithm, the analytical basis for light radiation hazard reduction of plus optical apparatus in ocular optical path is formed. The original apparatus concept for comparing is introduced to formulate the concepts and expressions of relative light radiation hazard reduction and absolute Based on light radiation hazard algorithm, the analytical basis for light radiation hazard reduction of plus optical apparatus in ocular optical path is formed. The original apparatus concept for comparing is introduced to formulate the concepts and expressions of relative light radiation hazard reduction and absolute light radiation hazard reduction, as well as the conversion between them. With the light limited mechanism of pupils, respective light radiation hazard reduction algorithm of tissues forward and rearward pupil is elicited and practical applications are introduced. By visual application analysis, the increasing rate of scotopic luminous efficiency can evaluate the level of visual lightness, and practical algorithm on the basis of increasing rate of dark luminous efficiency expression is elicited. By source changing analysis, light source color rendering evaluation method can evaluate the level of color vision, and the application standard of rendering index Ra for evaluating color rendering is given. The last part shows that this method can realize the purpose of systematic evaluation..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3253 (2010)
Spectral Imaging Technology Applied to Mixed Powder of Rhizoma Coptidis and Cortex Phellodendri Chinensis
Zhao Jing, Pang Qichang, Ma Ji, Liu Chuanming, Wang lin, Cui Daijun, and Meng Qingxia
In order to identify the adulteration of traditional Chinese medicine (TCM) powder quickly and control the quality of TCM powder effectively, spectral imaging analysis technology is used to test the mixed powder of rhizoma coptidis and cortex phellodendri chinensis. The standard samples of rhizoma coptidis and cortex pIn order to identify the adulteration of traditional Chinese medicine (TCM) powder quickly and control the quality of TCM powder effectively, spectral imaging analysis technology is used to test the mixed powder of rhizoma coptidis and cortex phellodendri chinensis. The standard samples of rhizoma coptidis and cortex phellodendri chinensis applied by National Institute for the Control of Pharmaceutical and Biological Products are used to construct the fingerprintatlas. After analyzing the differences of two fingerprints, the characteristic wave bands are obtained. Take 1 g of rhizoma coptidis powder and cortex phellodendri chinensis powder respectively, and mix them. The spectral images of mixed powder are captured. The spectral images are reconstructed with band ratio method and classified with threshold method. The technology realizes the identification of mixed powder and obtains the spatial distribution of samples. The results show that the spectral imaging analysis technology can resolve the problem of TCM powder adulteration and that the testing process is nondestructive and rapid..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3259 (2010)
Nonlinear Optics
Research on Parameters of Focused Laser Packet-Induced Plasma in Tranparent Materials
Zheng Jiangang, V. T. Platonenko, Yu. M. Mikhailova, Zhang Xiongjun, Li Mingzhong, Duan Wentao, Jiang Xinying, Wu Dengsheng, and Tian Xiaolin
Using the generalized nonlinear Schrdinger equation, the relation between the laser parameters and the place, size of the plasma induced by a focused laser packet in transparent materials have been simulated. Calculation shows that: the ultimate density of the induced plasma trends towards a constant for a given diffrUsing the generalized nonlinear Schrdinger equation, the relation between the laser parameters and the place, size of the plasma induced by a focused laser packet in transparent materials have been simulated. Calculation shows that: the ultimate density of the induced plasma trends towards a constant for a given diffraction length of the laser packet, and the region of the induced plasma becomes larger and longer with the increase of the laser power; for a given power laser packet the density of the induced plasma decreases with the increase of the diffraction length of the laser packet; for laser packets with different diffraction length the region of induced plasma extends to different direction with the increase of the laser power, which is consistent with the experimental results by Gordienko et al.. This study may be beneficial to understand the formation of the induced plasma in materials and push forward its application in laser processing..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3264 (2010)
Study on Waveband Optional Optical Sampling Based on Chirped Periodically Poled LiNbO3 Waveguide
Ning Chunmei, Yang Aiying, Shen Shikui, Wu Xiangyu, and Sun Yunan
Optical sampling covering C band and L band based on sum frequency generation (SFG) in chirped periodically poled LiNbO3(CPPLN) is studied. Based on coupled-wave equations, the simulations and numerical computations of the transmission rate and bandwidth are carried out. NRZ sequences of the signal pulses with the tranOptical sampling covering C band and L band based on sum frequency generation (SFG) in chirped periodically poled LiNbO3(CPPLN) is studied. Based on coupled-wave equations, the simulations and numerical computations of the transmission rate and bandwidth are carried out. NRZ sequences of the signal pulses with the transmission rate of 10 Gb/s are sampled. Distinct eye diagrams and quality factor Q are obtained by software-synchronized algorithm.The results show that arbitrary waveband inside C and L band can be sampled by tuning pump wavelength and that the bandwidth of the waveband is controllable by adjusting the waveguide length and the chirped coefficient of CPPLN waveguide. SFG in CPPLN waveguide used for optical sampling system has broader bandwidth and more flexible selectivity than that in PPLN waveguide..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3270 (2010)
Optical Design and Fabrication
Optical Geometric Method for LFR Mirror Field Arrangement Without Shading and Blocking
Du Chunxu, Wang Pu, Ma Chongfang, and Wu Yuting
In a linear Fresnel reflector(LFR), every mirror row was used to track the sunlight in real time and to reflect the sunlight to fixed linear receiver. Therefore, incidence angle and reflected angle of the sunlight and every mirror row tracking tilt angle vary throughout the year. This makes the analysis of shading and In a linear Fresnel reflector(LFR), every mirror row was used to track the sunlight in real time and to reflect the sunlight to fixed linear receiver. Therefore, incidence angle and reflected angle of the sunlight and every mirror row tracking tilt angle vary throughout the year. This makes the analysis of shading and blocking between adjacent mirror rows very complex. The calculating formulae of sun shadow length and skew length of LFR mirror row were obtained by the projective method. In order to get the relation of shading and blocking, shadow length and skew length were analysed, for example the minimum mirror row spacing and etc.. Finally, a examples of mirror spacing analysis and relationship of mirror elements arraryment and effective irradiance was given..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3276 (2010)
Projection Objective Design of Grating Light Modulator
Shi Lingna, Pan Yingjun, and Dong Guangxian
The projection objective of grating light modulator based on 4f signal processing system is designed, which uses LED as light source. By filtering the diffracted light via grating light modulator, the modulated image is amplified and projected. The design result shows that the total length of projection objective is 70The projection objective of grating light modulator based on 4f signal processing system is designed, which uses LED as light source. By filtering the diffracted light via grating light modulator, the modulated image is amplified and projected. The design result shows that the total length of projection objective is 70.71 mm, and the biggest caliber is 12.40 mm. The whole aberration is controlled within an ideal range, which can satisfy the image-forming requirement. The experimental system is built based on the design result, and the experimental result is in according with theoretical analysis, which shows the feasibility of the design..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3283 (2010)
A Quick Algorithm for Locating Ghost Coordinates in High-Power Laser Systems
Cen Zhaofeng, Li Xiaotong, and Deng Shitao
A quick algorithm for locating the ghost coordinates in high-power laser systems is presented for analyzing multi-reflection and multi-order diffraction ghosts in design so as to avoid damaging the systems. The primary paraxial ray and chief ray are traced and saved in a multi-pork tree expressed as a binary tree at thA quick algorithm for locating the ghost coordinates in high-power laser systems is presented for analyzing multi-reflection and multi-order diffraction ghosts in design so as to avoid damaging the systems. The primary paraxial ray and chief ray are traced and saved in a multi-pork tree expressed as a binary tree at the same time, the z coordianate zg of each ghost is determined by tracing the primary paraxial ray, and the intersection point of the chief ray and the plane z=zg is regarded as the position of the real ghost. Taking a tilt lens and the final optical assembly (FOA) with a diffraction optical component as examples, the space coordinates of some ghosts are predicted. Certified by high-density real ray tracing, optical energy is focused at the predictive position in corresponding ghost plane. The results show that the predicted ghost point is coincident with the area at which the real rays condense. The positions of 13124 ghosts in a laser system including 222 surfaces are found in 16 s using this algorithm..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3289 (2010)
Design of Three-Dimensional Superresolution Diffractive Optical Elements for Radially Polarized Beam
Cheng Kan, Tan Qiaofeng, Zhou Zhehai, and Jin Guofan
Three-dimensional superresolution diffractive optical elements (DOE) are designed for incidences of radially polarized light. The analysis of focusing properties of the radially polarized beam in the high numerical aperture focusing system shows that the longitudinal component of the focused radially polarized light doThree-dimensional superresolution diffractive optical elements (DOE) are designed for incidences of radially polarized light. The analysis of focusing properties of the radially polarized beam in the high numerical aperture focusing system shows that the longitudinal component of the focused radially polarized light dominates the three-dimensional intensity distribution of main lobe. Based on the global optimization method, three-dimensional superresolution DOE for the linearly polarized beam with 0 and π binary phase distribution are designed by linear programming method. Three-dimensional superresolution performances are calculated considering both transverse and longitudinal components of the focused radially polarized light. Although the optimized DOE may not be globally optimal for the radially polarized light, simulation results show that the radially polarized beam can realize better superresolution performances than the linearly polarized light, which also validates the optimization method for three-dimensional superresolution DOE considering only the longitudinal component of the focused radially polarized beam..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3295 (2010)
Aberration Analysis and Design of Four-Mirror Reflective Optical System
Liang Shitong, Yang Jianfeng, Xue Bin, Ruan Ping, and Wang Hongwei
Reflective optical systems have small size, light weight and excellent imaging performance, which makes it very popular in space remote sensing systems. The third order aberration expression and basic design process of four-mirror system are given by aberration analysis based on PW method. Two space remote sensing systReflective optical systems have small size, light weight and excellent imaging performance, which makes it very popular in space remote sensing systems. The third order aberration expression and basic design process of four-mirror system are given by aberration analysis based on PW method. Two space remote sensing systems using coaxial and abaxial four-mirror system is designed under the guidance of the aberration theory. The two systems have excellent imaging performance. The systems have compact structure and the physical length to the EFL ratio is about 1/6.4. Both of the size and weight meet the technical requirements, the correctness and practicality of the theoretical analysis are proved..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3300 (2010)
Optical Devices
Characteristics of Diffusers with Cascaded-Microlens Arrays
Zhang Xiaolei, Zhou Fang, Shen Su, and Chen Linsen
A new type of optical diffuser with cascaded microlens arrays (MLAs) is proposed. The diffuser is composed of a layer of MLAs with small aperture and high numerical aperture (NA) on output side and a layer of MLAs with large aperture and low NA on incident side. The influence of the parameters (such as sag height, aperA new type of optical diffuser with cascaded microlens arrays (MLAs) is proposed. The diffuser is composed of a layer of MLAs with small aperture and high numerical aperture (NA) on output side and a layer of MLAs with large aperture and low NA on incident side. The influence of the parameters (such as sag height, aperture etc.) of cascaded MLAs on the diffusing behavior is investigated by using of ray tracing method. The results show that the maximum luminance increases with the ratio of sag height to aperture and an additional 3%～5% optical gain can be accomplished by inserting another layer of MLAs with a height-aperture ratio of 0.01～0.15 on incident side. Experimental results are also demonstrated and the optical gain is measured as 40.06%..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3306 (2010)
Physical Optics
Angular Shift of Gaussian Beams at Metamaterial Interfaces
Huang Wenjing, Luo Hailu, and Wen Shuangchun
On the basis of angular spectrum representation, a formalism is established to study the angular shift of a Gaussian beam at the interface associated with negative, near-zero, and ultrahigh-index metamaterials. The difference and relation between beam′s angular shift and traditional Goos-Hnchen shift, Imbert-Fedorov sOn the basis of angular spectrum representation, a formalism is established to study the angular shift of a Gaussian beam at the interface associated with negative, near-zero, and ultrahigh-index metamaterials. The difference and relation between beam′s angular shift and traditional Goos-Hnchen shift, Imbert-Fedorov shift are revealed. It is found that the divergence angular shift increases with decrease of the refractive index and loss. Additioanlly, in the interface of negative index media, the angular shift can counteract the negative Goos-Hanchen shift which leads to positive longitudinal divergence angular shift. When the refraction index is close to zero, the transverse divergence angular shift disappears in a large range of incident angle range. The transverse divergence angular shift is unobvious as refraction index is very large. So, metamaterials with close to zero and very large refraction index can be used to avoid the angular dispersion caused by angular shift..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3311 (2010)
Effect of Primary Spherical Aberration on Tight Focusing of Elliptically Polarized Vortex Beams
Liang Chongqing, Tang Zhilie, and Guo Lina
The focusing properties of elliptically polarized vortex beams through a high numerical-aperture objective with primary spherical aberration are studied. Based on vectorical Debye theory, the complex amplitude distribution of elliptically polarized Bessel-Gaussian beams through a high numerical-aperture objective with The focusing properties of elliptically polarized vortex beams through a high numerical-aperture objective with primary spherical aberration are studied. Based on vectorical Debye theory, the complex amplitude distribution of elliptically polarized Bessel-Gaussian beams through a high numerical-aperture objective with primary spherical aberration is derived. Numerical calculation is performed to analyze intensity distribution and phase distribution of the right-handed elliptically (RE) polarized beam and the left-handed elliptically (LE) polarized beam with different primary spherical aberration coefficients. It is shown that the intensity distribution of the vortex beams decreases with the spherical aberration coefficient, but the size of dark core increases. Additionally, the phase distribution of longitudinal component of RE polarized beam presents the spiral structure and the radii of the dislocation lines for RE polarized beam and LE polarized beam increase gradually with the primary spherical aberration coefficient. With the increment of spherical aberration coefficient, the converging point gradually deviates from the focal plane and the longitudinal field changes..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3317 (2010)
Propagation and Evaluation of Lateral Linear Momentum of Optical Vortices
Yang Dexing, Ren Xiaoyuan, He Dongsheng, Cui Yong, and Gan Xuetao
The angular momentum distributions and their propagation evaluation characteristics of optical vortices, especially vortices with the complicated topological structure, which are difficult to measure accurately through an experiment, can be obtained by numerical computation. The lateral linear momentum density of opticThe angular momentum distributions and their propagation evaluation characteristics of optical vortices, especially vortices with the complicated topological structure, which are difficult to measure accurately through an experiment, can be obtained by numerical computation. The lateral linear momentum density of optical vortices is obtainable by neglecting the longitudinal component of linear momentum density of linearly polarized optical field, and the angular momentum distribution is characterized by the azimuth component of lateral linear momentum density. The propagations of a single Laguerre-Gaussian beam and a vortex beam superimposed by two Laguerre-Gaussian beams with different topological charges are numerically simulated in free space. Through the simulation, the transverse profiles of intensities, phases, and lateral linear momentum density in Rayleigh range are obtained. It is shown that the lateral linear momentum density is reduced, and that simultaneously the radial component of linear momentum is increased due to the beam diffraction. Consequencely, the radial mechanics is enhanced and the azimuth one is abated. Therefore, the beam cross sections which are far away from the beam waist are not suitable to be utlized for the manipulation of microparticles..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3323 (2010)
Quantum Optics
Analysis of Influence of Magneto-Optical Effect on Quantum Key Distribution System with Phase Coding
Han Baobin, Pei Changxing, and Liu Dan
Being affected by birefringence, the polarization state of single photon is randomly and slowly altered during the transmission in single mode fiber. This influences the performance of quantum key distribution system. The “plug and play” system with Faraday rotation mirror is theoretically analyzed by the use of probabBeing affected by birefringence, the polarization state of single photon is randomly and slowly altered during the transmission in single mode fiber. This influences the performance of quantum key distribution system. The “plug and play” system with Faraday rotation mirror is theoretically analyzed by the use of probability wave superposition. The results show that the bidirectional transmission of a single photon through the same fiber can effectively offset the influence of fiber birefringence, but is vulnerable to nonreciprocity effects such as magneto-optical effect. The probability of normal interference fringes, formed by the single photon reaching the interferometer successfully, decreases with the increase of magneto-optical rotation angle. When the rotation angle is greater than 42°, the probability of forming the normal interference fringes is close to 0..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3328 (2010)
Ghost Imaging without Beamsplitter in Thermal Optical Field
He Shibei, Shen Xia, Wang Hui, Gong Wenlin, and Han Shengsheng
Ghost imaging has attracted much attention since it was realized.Many significant results have been achieved in the field of ghost imaging, in which the beamsplitter is an indispensable optical component. However, the existence of the beamsplitter hinders the wider application of ghost imaging, especially with the natuGhost imaging has attracted much attention since it was realized.Many significant results have been achieved in the field of ghost imaging, in which the beamsplitter is an indispensable optical component. However, the existence of the beamsplitter hinders the wider application of ghost imaging, especially with the natural light. A method to realize ghost imaging without beamsplitter by modulating the light intensity on the plane of light source is introduced. Then it is studied theoretically and experimentally. Finally, for further applications, the basic model is improved to a more advanced one. The success of the ghost imaging without beamsplitter is very significant to the applications of ghost imaging..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3332 (2010)
Multiformity of Subtypes of Cascade-Type Four-Level Optical Quantum Coherence Systems
Liu Xiaodong, Meng Dongdong, Zhang Senlin, and Yan Xuequn
The cascade four-level system has six possible optical transition channels and provides many real subtypes for theoretical and experimental studies about quantum coherence effects. Using Boolean algebra method, according to possible existing transition channels, combining electric dipole selection rule, all channel subThe cascade four-level system has six possible optical transition channels and provides many real subtypes for theoretical and experimental studies about quantum coherence effects. Using Boolean algebra method, according to possible existing transition channels, combining electric dipole selection rule, all channel subtypes of cascade four-level scheme are studied, the realistic channel subtypes of 17 three transition channels and 2 four transition channels are got. Furthermore, 168 real intensity subtypes appear when one distinguishes each of related laser field intensities only. This multiformality of realistic channel and intensity subtypes provides more subtle energy level scheme-choosing chances for quantum optics, quantum information science, precise laser spectroscopy, etc..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3336 (2010)
Remote Sensing and Sensors
A Comparative Study of Two Remote Sensing Image Adjacency Effect Correction Algorithms Based on SHDOM Empirical Equation and Synchronized Measured Spectral Data
Wang Qian, Chen Xue, Ma Jianwen, and Chen Jianping
In terms of background reflectance computation and true reflectance acquisition, the two adjacency effect correction algorithms are studied comparatively. One is based on three-dimensional radiative transfer model SHDOM (Spectral Harmonics Discrete Ordinary Method) empirical equation for the nadir-viewing optical remotIn terms of background reflectance computation and true reflectance acquisition, the two adjacency effect correction algorithms are studied comparatively. One is based on three-dimensional radiative transfer model SHDOM (Spectral Harmonics Discrete Ordinary Method) empirical equation for the nadir-viewing optical remote sensing image and the other is based on the synchronically measured spectral data. The data sources are Landsat-5 TM image with synchronized measured spectral data of sand, and ASTER image with synchronized measured spectral data of grass. The results demonstrate that the adjacency effect correction algorithm based on SHDOM empirical equation has more profound theoretical foundation according to the radiative transfer theory, and the image corrected by the adjacency effect correction algorithm based on the synchronized measured spectral data looks better..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3342 (2010)
400～900 nm Spectral Irradiance of Cryogenic Radiometer-Based Irradiance Standard Lamp Using System Level Calibration Method
Chen Hongyao, Zhang Liming, Zou Peng, Xie Ping, Zheng Xiaobing, and Qiao Yanli
To improve the accuracy of radiation work standards and meet the urgent need of high-accuracy remote sensors calibration, a study about establishment of irradiance of standard lamp with spectrum range from 400 to 900 nm is carried out using the cryogenic radiometer as the primary standard and filter radiometer as the tTo improve the accuracy of radiation work standards and meet the urgent need of high-accuracy remote sensors calibration, a study about establishment of irradiance of standard lamp with spectrum range from 400 to 900 nm is carried out using the cryogenic radiometer as the primary standard and filter radiometer as the transfer standard. Through with a recursive iterative optimization algorithm, a physical model of the irradiance standard lamp and a filter detector spectral response system level calibration by a laser imported integrating sphere, the continuous spectral distribution of the irradiance standard lamp can be calculated. The method of system level calibration avoids the uncertainty induced by filter transmittance, geometric factor measurement uncertainty and discord between use and calibration states. Preliminary results show that the difference between standard lamp irradiance calibrated by ITS-90 black body and calculated value by the method is within the uncertainty of calibration. The transfer stand of an irradiance standard lamp based on cryogenic radiometer is tried in China. The method could greatly improve the accuracy of current optical radiation work standard. The research has important significance in the optical radiation measurement and remote sensors, especially in hyper-spectral remote sensors calibration..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3349 (2010)
Spectroscopy
Influence of Fluorescent Medium Optical Characteristics on Stimulated Raman Scattering
Sun Xiuping, Cao Anyang, Yu Miao, Liu Mingbo, Men Zhiwei, Fang Wenhui, Sun Chenglin, Gao Shuqin, Li Zuowei, and Yang Jiange
The fluorescence is demonstrated a well out-seeding effect in the stimulated Raman scattering (SRS), which can drastically lower the SRS threshold and enhance the intensity of scattering-mode. The solution of fluorescent seeding in CS2 is used to the study of the fluorescence enhancement SRS in liquid-core optical fibeThe fluorescence is demonstrated a well out-seeding effect in the stimulated Raman scattering (SRS), which can drastically lower the SRS threshold and enhance the intensity of scattering-mode. The solution of fluorescent seeding in CS2 is used to the study of the fluorescence enhancement SRS in liquid-core optical fiber (LCOF). The results demonstrate that the stronger intensity of Stokes and anti-Stokes scattering light can be observed at low pump energy. The rhodamine B of narrow fluorescent spectrum is used, and the high intensity of first-order anti-Stokes line and low intensity of first-order Stokes line are obtained; and the β-carotene of broad fluorescent seeding is used, the seventh-order Stokes lines are obtained at low pump energy. So, the scattering mode of SRS can be selectively enhanced according to the different optical characteristics of fluorescent seeding..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3354 (2010)
Vision, Color, and Visual Optics
Study on the Influence of Gloss on Printed Samples Medium-Small Color Difference with the Psychophysical Method of Comparison
Huang Min, Wang Lili, and Liu Haoxue
In order to reveal the effect of gloss on medium-small color difference evaluation, the printed samples were prepared by ink jet printer on matte, semi-gloss two papers with different gloss levels at the 5 basic CIE color centers. About 30 color samples were made on two kinds of paper; experiment of color difference waIn order to reveal the effect of gloss on medium-small color difference evaluation, the printed samples were prepared by ink jet printer on matte, semi-gloss two papers with different gloss levels at the 5 basic CIE color centers. About 30 color samples were made on two kinds of paper; experiment of color difference was carried out by 20 observers with normal color vision based on the psychophysical method of comparison. The standardized residual sum of squares (STRESS) and F test were proposed to test the four classical color-difference formulae, CIELAB, CMC, CIE94, CIEDE2000 and CAM02 series CAM02-LCD,CAM02-SCD,CAM02-UCS. For the original color difference formulae, CIEDE2000 performed the best, and CIELAB color difference formulae performed the worst, while there′s still room for CIE94 for improvement. For the optimized kL values, the higher gloss is, the smaller kL is, which indicated that the lightness difference are more noticeable for the higher gloss printed samples for evaluating color difference..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 30, Issue 11, 3359 (2010)
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