Contents
2013
Volume: 33 Issue 6
50 Article(s)
Export citation format
Atmospheric Optics and Oceanic Optics
Development and Performance Test of the 961-Element Deformable Mirror
Lin Xudong, Liu Xinyue, Wang Jianli, Li Hongwen, Wang Fuguo, Wei Peifeng, Wang Liang, Yao Kainan, and Jia Jianlu
A 961-element deformable mirror (DM) and its control system are developed to satisfy the demand of the adaptive optical system of the astronomical telescope. The performance of the deformable mirror is tested by Zygo interferometer. Three tests are carried out, which include the response function test of individual actA 961-element deformable mirror (DM) and its control system are developed to satisfy the demand of the adaptive optical system of the astronomical telescope. The performance of the deformable mirror is tested by Zygo interferometer. Three tests are carried out, which include the response function test of individual actuator, the push-pull capability test of the neighbor actuators and the coupling test between two actuators. Then, the correction capability of the deformable mirror is tested by performing the Waffle mode test, Zernike polynomial fitting test and flattening test. The testing results show that the max correction ability of the deformable mirror actuated by individual actuator is ±2.5 μm. The inter-actuator stroke is 4 μm. And the coupling between two neighbor actuators is 23%. Compared to the former 137-element deformable mirror, the fitting capability of the Zernike polynomials of the 961-element deformable mirror is much better. The surface flatness of the deformable mirror after flattening is better than root-meat-square (RMS) value of λ/70 (λ=632.8 nm). The test results satisfy the requirements of the deformable mirror which is to be used in the adaptive optical system of the astronomical telescope..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 601001 (2013)
Research of Aerosol Extinction Inverted with Look-Up Table Method Based on Multi-Axis Differential Optical Absorption Spectroscopy
Wu Fengcheng, Xie Pinhua, Li Ang, Si Fuqi, Xu Jin, Fan Guangqiang, Liu Jianguo, and Liu Wenqing
The properties of aerosol include physical, chemical and optical characteristics. Whiles the determinant of optical parameters is the prerequisite for accurate estimation to the radiation forcing. A method for determining aerosol extinction with look-up table is presented combined with radiative transfer model. Also thThe properties of aerosol include physical, chemical and optical characteristics. Whiles the determinant of optical parameters is the prerequisite for accurate estimation to the radiation forcing. A method for determining aerosol extinction with look-up table is presented combined with radiative transfer model. Also the effects of single scatter albedo rate, asymmetry parameter and ground albedo rate on the simulation of O4 air mass factor are studied. Using O4 air mass factor based on multi-axis differental optical absorption spectroscopy (MAX-DOAS) measurement at different elevation angles, simulated O4 air mass factor and the factor got through the radiative transfer model are compared. The aerosol optical density, boundary height and extinction coeffcient are retrieved after the process of minimization and linearly interpolation. Creating a look-up table, the aerosol extinction is determined at Shanghai Baoshan monitoring site using MAX-DOAS. Compared with lidar, it shows a reasonable agreement. It′s turned out that the look-up table can be used to detect the properties of aerosol..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 601002 (2013)
Simulative Study of Optical Pulse Propagation in Water Based on Fournier-Forand and Henyey-Greenstein Volume Scattering Functions
Wei Anhai, Zhao Wei, Han Biao, Xie Xiaoping, Hu Hui, and 1Su Yulong
A simulative model with Monte Carlo method is established based on Fournier-Forand and Henyey-Greenstein volume scattering functions, by which propagation characteristics of optical pulse underwater can be analyzed. By using this model, the influence of scattering particles′ relative refractive index and size distributA simulative model with Monte Carlo method is established based on Fournier-Forand and Henyey-Greenstein volume scattering functions, by which propagation characteristics of optical pulse underwater can be analyzed. By using this model, the influence of scattering particles′ relative refractive index and size distribution on optical pulse propagation in water is analyzed. The results show that, with the increase of the relative refractive index of scattering particles and small scattering particles′ relative quantity, the width of optical pulse is broadened more evidently in time domain, the forward scattering becomes weaker with a more disperse space distribution and arrival angles′ distribution. Compared with traditional simulative models, the method presented is more effective..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 601003 (2013)
Numerical Calculation of Optical Properties of Multi-Particle Size Aerosol Aggregate Particles
Huang Chaojun, Wu Zhensen, Liu Yafeng, and Long Shuming
Based on cluster-cluster aggregation (CCA) model, Monte Carlo method is taken to simulate the multi-particle size aerosol aggregates particles which consist of spherical original particles with different radius. According to electrical structure of substance, the aerosol aggregates particles are dispersed into a seriesBased on cluster-cluster aggregation (CCA) model, Monte Carlo method is taken to simulate the multi-particle size aerosol aggregates particles which consist of spherical original particles with different radius. According to electrical structure of substance, the aerosol aggregates particles are dispersed into a series of dipoles. By using discrete dipole approximation method, the values of optical characteristic quantities are obtained, such as scattering, absorption and extinction efficiency factors of multi-particle size aerosol aggregates particles with different incident wavelengths. Numerical results are compared with the characteristic quantities of the single particle size aerosol aggregates particles and the spherical aerosol particle of equal volume. Results show that the value of optical characteristic quantities of aerosol particles depends on the wavelength of incident light and shape of aerosol particles. There is significantly difference of the optical properties between single-particle size aerosol aggregates particles and multi-particle ones. The multi-particle size aerosol aggregates particles model is much closer to real aerosol particles. The findings provide a certain reference for comprehensive understanding and researching on the optical properties of aerosol particles..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 601004 (2013)
Atomic and Molecular Physics
Nonsequential Double Ionization of Xe Atoms by Elliptically Polarized Few-Cycle Laser Pulses
Yu Benhai, Li Yingbin, and Li Fangtao
With the classical ensemble model, the nonsequential double ionization (NSDI) of Xe atoms is investigated by the elliptically polarized few-cycle laser pulses at the laser intensity of 2.5×1014 W/cm2 and the laser wavelength of 780 nm. The results show that the momentum spectra of the final-state correlated electrWith the classical ensemble model, the nonsequential double ionization (NSDI) of Xe atoms is investigated by the elliptically polarized few-cycle laser pulses at the laser intensity of 2.5×1014 W/cm2 and the laser wavelength of 780 nm. The results show that the momentum spectra of the final-state correlated electron pairs from NSDI along the long axis of the polarization plane are mainly distributed in the first and third quadrants, showing strongly correlated behavior at the various carrier-envelop phases (CEPs). The rate of the total number for the final-state correlated electron pairs whose momentum spectra are distributed in the first and third quadrants shows decrease firstly then increase as CEP decreases. By analyzing the trajectories, the events of NSDI are due to the recollision at this laser pulse and the processes of NSDI are dominated by (e, 2e) ionization. In addition, the laser phase at the recollision also strongly depends on CEP..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 602001 (2013)
Detectors
Influence on Afterburning on Infrared Radiation of Solid Rocket Exhaust Plume
Liu Zunyang, Shao Li, Wang Yafu, and Sun Xiaoquan
Aimed at studying the influence of afterburning on the infrared radiation of a solid rocket exhaust plume, a model which can calculate the afterburning flow field and infrared radiation of a solid rocket exhaust plume is founded. The Fluent software is used to calculate the afterburning flow field of a solid rocket exhAimed at studying the influence of afterburning on the infrared radiation of a solid rocket exhaust plume, a model which can calculate the afterburning flow field and infrared radiation of a solid rocket exhaust plume is founded. The Fluent software is used to calculate the afterburning flow field of a solid rocket exhaust plume. Then, a narrow band model and the Mie scattering theory are employed to calculate the radiation parameters of gas and Al2O3. The finite volume method (FVM) is used to solve the radiation transfer equation (RTE). Based on this model, the influences of afterburning on the infrared radiation of solid rocket exhaust plumes both without and with Al2O3 are studied respectively, and the cause of the difference of the influence degree between the two cases is analyzed. Results show that, afterburning can enhance the infrared spectral radiation of the plume without Al2O3 greatly, and the average increase radio of the two domain radiation band of 2.5～3.0 μm and 4.2～4.7 μm achieve 46.4% and 58.4% respectively. Besides, the radiation increment of plume with Al2O3 is smaller, and the average increase proportions of the two radiation bands 2.5～3.0 μm and 4.2～4.7 μm achieve 7.7% and 8.4% respectively. It is considered that the difference of infrared radiation increment results from the difference of temperate increment between the two cases..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 604001 (2013)
Diffraction and Gratings
Diffraction Properties of Frequency Chirped Gaussian Pulse Laser Beams through Volume Gratings
Chen Huili, Yan Aimin, Hu Zhijuan, Shi Wangzhou, Jin Yadong, and Lü Congling
Based on the coupled wave equations that describe the interaction of laser pulse with volume gratings, the diffraction properties of volume gratings illuminated by linear chirped pulse with various input pulse widths and chirped parameters are studied. The properties of the spectral intensity and phase of diffraction pBased on the coupled wave equations that describe the interaction of laser pulse with volume gratings, the diffraction properties of volume gratings illuminated by linear chirped pulse with various input pulse widths and chirped parameters are studied. The properties of the spectral intensity and phase of diffraction pulses are investigated. The calculations demonstrate that the diffraction spectral width is influenced by the input pulse width, chirped parameter and the spectral width of the volume grating. With the incident pulse width increasing, the diffraction spectral width is reduced, but the diffraction efficiency increases. With the increase of the chirped parameter, the diffraction spectral width is increased, but the diffraction efficiency decreases. The change of diffraction phase spectra is increased with the increase of the input pulse width and the decrease of the chirped parameter, and the curve of the phase spectral distribution is asymmetric. We also find that the Bragg diffraction of the volume grating can shape the linear chirped pulse laser, and keep perfectly the linear chirp characteristic of the diffraction pulse, when the grating vector and input angle are selected properly..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 605001 (2013)
Design and Fabrication of 16 Channel 200 GHz InP Based Array Waveguide Gratings
Zhao Jianyi, Chen Xin, Qian Kun, Zhang Di, Wang Lei, Zhou Ning, Huang Xiaodong, and Liu Wen
A 16-channel InP based array waveguide grating (AWG) with 200 GHz channel spacing is designed and fabricated for monolithic photonic integrated circuits. Polarization independent deep ridge waveguide is applied to reduce chip size and improve the integration level. By using the technologies of metal organic chemical vaA 16-channel InP based array waveguide grating (AWG) with 200 GHz channel spacing is designed and fabricated for monolithic photonic integrated circuits. Polarization independent deep ridge waveguide is applied to reduce chip size and improve the integration level. By using the technologies of metal organic chemical vapor deposition (MOCVD), lithography and induced coupler plasma etching (ICP), the chip is fabricated in our laboratory successfully. The test results show that the insertion loss is about -10 dB, crosstalk is less than -15 dB..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 605002 (2013)
Fiber Optics and Optical Communications
Graphic Comparisons between Hermite-Gaussian Modes and Laguerre-Gaussian Modes
Jiang Yuesong, Xu Hongwu, Tang Hua, and He Yuntao
The Hermite-Gaussian modes and Laguerre-Gaussian modes are briefly described. The three-dimensional plots of Hermite-Gaussian modes and Laguerre-Gaussian modes in the plane z=0 are drawn. For the sake of revealing the relation among the various modes of Hermite-Gaussian and Laguerre-Gaussian, contour maps for modal ordThe Hermite-Gaussian modes and Laguerre-Gaussian modes are briefly described. The three-dimensional plots of Hermite-Gaussian modes and Laguerre-Gaussian modes in the plane z=0 are drawn. For the sake of revealing the relation among the various modes of Hermite-Gaussian and Laguerre-Gaussian, contour maps for modal orders varying from (0,0) to (2,2) are plotted. The characteristics of the mode order number and the peak value, the change of peak value, the extending area and the symmetry are obtained, respectively. The similarities and differences of the characteristics can also be acquired through the comparisons. The minimum modes of Hermite-Gaussian and Laguerre-Gaussian are consistent, which can be described both in images and formulas. The differences between the electric (magnetic) field and averaged Poynting vector have relationship with the mode. The image of amplitude intensity of the cross-sectional image changes along with the increase of transmission distance. The waist of the beam and peak value also have some connections with the transmission distance..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 606001 (2013)
Effect of Atmospheric Turbulence Aberration on the Bit-Error Performance of Homodyne Binary Phase Shift Keying Coherent Optical Communication
Wu Yunyun, Li Xinyang, and Rao Changhui
The bit error rate (BER) at different atmospheric turbulence conditions is analyzed, which illustrates the adverse affection of wave-front aberration caused by atmospheric turbulence on binary phase shift keying（BPSK） coherent optical communication system. Atmospheric turbulence aberration can act on optical communicatThe bit error rate (BER) at different atmospheric turbulence conditions is analyzed, which illustrates the adverse affection of wave-front aberration caused by atmospheric turbulence on binary phase shift keying（BPSK） coherent optical communication system. Atmospheric turbulence aberration can act on optical communication system, which leads to bit error and is independent of system signal-to-noise ratio (SNR). Simulation results note that bit error is prone to emerge in the case of infinite SNR, when the peak-to-valley (PV) value of wave-front of received optical signal is greater than one wavelength. And the PV value of wave-front is strictly required with the decreasing of SNR. In addition, coherent mixing efficiency decreases rapidly, which is caused by the intensity fluctuation and phase aberration, consequently, resulting in the system bit error rate increasing..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 606002 (2013)
Imaging Systems
Influence of Charge Coupled Device Saturation on PIE Imaging
Wang Baosheng, Gao Shumei, Wang Jicheng, Zhu Jianqiang, and Liu Cheng
Based on the analysis of the influence of the charge coupled device (CCD) saturation on the image quality of ptychographical iterative engine (PIE), an improved reconstruction algorithm is proposed to get accurate reconstruction from partially saturated data. Compared with the common algorithm, the suggested method canBased on the analysis of the influence of the charge coupled device (CCD) saturation on the image quality of ptychographical iterative engine (PIE), an improved reconstruction algorithm is proposed to get accurate reconstruction from partially saturated data. Compared with the common algorithm, the suggested method can remarkably reduce the data acquisition time without degrading the spatial resolution of the reconstruction, so the requirement on the stability of the experimental setup and the specimen is obviously reduced, and this method is quite meaningful for a wide range of applications of PIE..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 611001 (2013)
Depth Estimation with a Panoramic Stereo Imaging System
Tian Yanbing, Bai Jian, and Huang Zhi
An information extraction method based on a panoramic stereo imaging system with double coaxial panoramic annular lens (PAL) units is presented. Its imaging circles are concentric so that depth information of 360° horizontal field-of-view (FOV) object can be extracted in real time. Based on imaging principles, theAn information extraction method based on a panoramic stereo imaging system with double coaxial panoramic annular lens (PAL) units is presented. Its imaging circles are concentric so that depth information of 360° horizontal field-of-view (FOV) object can be extracted in real time. Based on imaging principles, the system is calibrated with a model that can accommodate the characteristics of a non-single viewpoint system, and the calibration results are verified. The scale-invariant feature transform (SIFT) algorithm is applied to the corresponding point matching, and it makes full use of collinear constraint of the system to improve the matching speed and accuracy. Effective depth information is extracted from the captured image with applying triangulation principle. Depth information extraction experiments are performed, and the results and error analysis are given. This system can restore depth information effectively, and its error rate of 3-m distance range is within ±5.2%, which proves the feasibility of this system..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 611002 (2013)
Infrared Illumination Model and Infrared Scene Simulation Based on Blinn-Phong Model
Hu Haihe, Bao Tingzhu, Han Qiang, and Zheng Haijing
In order to simulate infrared feature of the scene and infrared high light phenomenon, the visual illumination model in computer graphics is improved according to the principle of infrared imaging, the visual Blinn-Phong model is improved and remodeled into an infrared illumination model by introducing self radiation, In order to simulate infrared feature of the scene and infrared high light phenomenon, the visual illumination model in computer graphics is improved according to the principle of infrared imaging, the visual Blinn-Phong model is improved and remodeled into an infrared illumination model by introducing self radiation, considering the energy transfer between radiation sources and the object surface in the scene, and making the imaging effect of the object surface conform with corresponding law. In the aspect of realizing simulation, a new radiation energy computing method of the reflection area is proposed to simulate infrared high light effect based on the geometry features of the target. The reflection area is determined according to the target geometry, then infrared high light effect of the target is simulated by computing total energy which is calculated by the information of self-radiance of the incidence point, diffuse reflection rate and specular reflection rate of the material, and normal vector of the reflection point, the position and orientation of the detector and so on. It shows the validation of infrared illumination model and the simulation method of high light effect..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 611003 (2013)
Instrumentation, Measurement and Metrology
Analysis and Verification for Accuracy of Ritchey Angle in Flat Mirror Test
Zhu Shou, and Zhang Xiaohui
In order to improve the accuracy of Ritchey-Common (RC) method, the effect of accuracy of Ritchey angle on test results is mainly discussed. By means of simulations, the measured accuracy of surface error can reach 0.01λ(λ=0.6328 μm) when Ritchey angle′s range is optimized between 20°~50°. The error of RitcheIn order to improve the accuracy of Ritchey-Common (RC) method, the effect of accuracy of Ritchey angle on test results is mainly discussed. By means of simulations, the measured accuracy of surface error can reach 0.01λ(λ=0.6328 μm) when Ritchey angle′s range is optimized between 20°~50°. The error of Ritchey angle is simulated to analyze the influence on measured result. When the error of Ritchey angle is controlled within ±1°, the accuracy of residual error between fitting results and original surface can be decreased to 0.0007λ and meets the measured requirement. To avoid the measurement error of Ritchey angle, the ratio of image size on pupil plane is used to calculate the Ritchey angle, and this method′s accuracy can reach to 0.2°. Three Ritchey angles are chosen in the experiment and combined with each two of them. For the residual error between Zygo measurement and group of 29.6° & 47.8° measurement, the peak valley (PV) is 0.068λ and the root mean square (RMS) value is 0.0105λ. The results demonstrate that the choice of Ritchey angle and its calculation accuracy are important to RC method..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 612001 (2013)
Thermal Wave Nondestructive Testing of Honeycomb Defects and Finite Element Modeling
Huang Xinping, Tao Ning, Jiang Yulong, Wang Zhonghua, and Zhang Cunlin
The main defects of honeycomb structure in use are debond and water. Thermal wave nondestructive testing technology uses the pulse to heat the sample and thermal camera to detect the surface temperature so as to detect the defects of object information. The experimental results show that the temperature of the water poThe main defects of honeycomb structure in use are debond and water. Thermal wave nondestructive testing technology uses the pulse to heat the sample and thermal camera to detect the surface temperature so as to detect the defects of object information. The experimental results show that the temperature of the water position is lower than the temperature of the reference area. Based on this phenomenon, the Ansys finite element software is used to simulate the pulsed thermography, and the simulation results are compared with the actual test results, which verify that the finite element method is feasible to infrared non-destructive testing. The simulation and identification of the debond, water and oil defects are made to provide theoretical foundation for the actual experiment..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 612002 (2013)
High Precise Testing of Asphere with Computer-Generated Hologram and Error Evaluation
Gao Songtao, Sui Yongxin, and Yang Huaijiang
Computer-generated hologram (CGH) is more and more popularly applied in the high-precision testing of asphere as high-accuracy null compensator. The errors of design, coding, fabrication and alignment restrict the testing precision. A practicable method to test the asphere precisely is presented, and the calibration ofComputer-generated hologram (CGH) is more and more popularly applied in the high-precision testing of asphere as high-accuracy null compensator. The errors of design, coding, fabrication and alignment restrict the testing precision. A practicable method to test the asphere precisely is presented, and the calibration of CGH substrate, the calibration of reference surfaces, as well as distortion correction to improve the testing precision are accomplished. In order to obtain the measurement precision, in addition to the traditional root square sum (RSS) error analysis, the testing precision is directly evaluated through experimental comparison with the method of aberration free image conjugate point. The experimental result shows that the testing precision of asphere with CGH could reach 3.9 nm [root mean square (RMS)]..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 612003 (2013)
Investigation on On-Line Optical Fiber Surface Plasma Resonance Sensors Based on Frequency Modulation Spectroscopy
Fu Lihui, and Yin Wenqing
An optimal structure of on-line optical fiber surface plasma resonance (SPR) sensors is proposed based on principle of frequency modulation. On the basis of theoretical analysis, numerical simulation and measured results, the optical fiber SPR sensing probes can be regarded as an absorbing medium with a centro symmetriAn optimal structure of on-line optical fiber surface plasma resonance (SPR) sensors is proposed based on principle of frequency modulation. On the basis of theoretical analysis, numerical simulation and measured results, the optical fiber SPR sensing probes can be regarded as an absorbing medium with a centro symmetric absorption spectrum function, whose central wavelength at absorbing peak has a red-shift as increasing the refractive index of measured medium. The features of this centro symmetric absorption spectrum function make it possible to overcome the negative effect on measurement sensitivity originating from zero-value point of differential spectra at absorbing peak in directly measuring spectral method by the application of frequency modulation principle. And the adverse effects, rising from the intensity fluctuation of light source and in light propagating paths, can be suppressed by introduction of reference light path and negative feedback closed-loop system structure. The probes, which are made up of 15-mm long silica multi-mode optical fiber plated with 50-nm thick gold film, are applied in the proposed model, the corresponding experiments are arranged to measuring different liquid mediums with the index range of 1.33000~1.43000 refractive index unit (RIU).Then, discussion and analysis are carried out based on the data, which are got from the proposed method and other methods, such as Abbe refractometer, optical fiber spectrometer and numerical emulation. The results indicate that the precision of the proposed model is 0.00016 RIU at the range of 1.33200~1.37580 RIU, which is the same as measured results by applying optical fiber spectrometer with 0.4 nm wavelength resolution, and the precision is 0.000710 RIU at the range which is better than measured results by using optical fiber spectrometer with 0.0009 RIU. Therefore, the feasibility and reliability of the proposed method and the application for on-line measurement can be confirmed..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 612004 (2013)
A Method Based on Phase Shifting Algorithm for Fast Measurement of Stress Retardation of Optical Glass
Li Jinpeng, Chen Lei, Wulan Tuya, Yang Mingxiao, Zhou Shu, Zhu Ronggang, and Zheng Donghui
In order to determine the stress retardation distribution of optical glass, a novel method based on phase shifting algorithm and autocollimation method is proposed. An enlargement of the retardation of specimen can be achieved because of the autocollimation architecture. The phase shift step is fixed on according to thIn order to determine the stress retardation distribution of optical glass, a novel method based on phase shifting algorithm and autocollimation method is proposed. An enlargement of the retardation of specimen can be achieved because of the autocollimation architecture. The phase shift step is fixed on according to the contrast of stress fringe patterns. The stress retardation can be acquired by analyzing a set of phase shifting stress fringe patterns with high contrast. The simulated result shows an accuracy of 0.2 nm/cm. The experimental result indicates that the retardation in the central area of annealed glass cube is 3 nm/cm while in the edge area it is 9 nm/cm. Fast stress retardation measurement with high precision can be realized by this method..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 612005 (2013)
Effect of Assembly and Manufacturing Error for Wide-Viewing-Angle Quarter Waveplate on Polarimetry
Dong Juan, and Li Yanqiu
A waveplate is used to measure the polarization effects in optical systems. For a ultrahigh numerical aperture (NA) imaging system with a large angle of incidence, the light concerned may be not parallel to the optical axis of the system, but a conical light beam with a large angle to the optical axis of the system. ThA waveplate is used to measure the polarization effects in optical systems. For a ultrahigh numerical aperture (NA) imaging system with a large angle of incidence, the light concerned may be not parallel to the optical axis of the system, but a conical light beam with a large angle to the optical axis of the system. Therefore, the conventional double-plate type 1/4 waveplate can not be used in such systems. Instead of it, a four-plate wide-viewing-angle (WVA) 1/4 waveplate composed by positive and negative crystals can be used. The additional retardation caused by WVA 1/4 plate is analyzed in assembly angle error with three direction and two manufacturing errors. It is found that when the WVA 1/4 waveplate assembly error and the optical axis error of one piece crystal are both ±2°in the lithography system of NA of 1.35, the retardation error deduced by the latter relative to the former is above ten times. The deviation of light polarization degree (DOP) on mask level of high-NA lithographer is analyzed caused by the maximum additional retardation of WVA 1/4 waveplate, which comes from assembly and manufacturing error. As a result, It is concluded that when the retardation error is in the range of ±10°, the DOP deviation can be controlled in the scope of one in a thousand..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 612006 (2013)
Research on Fully Automatic Camera Calibration Method
Xu Yong, Guo Pengyu, Long Gucan, Zhang Xiaohu, and Yu Qifeng
Attention is focused on fully automatic camera calibration, and a calibration method based on three-dimensional (3D) reference points is proposed. This method acquires camera parameters through three steps: automatic recognition, automatic matching and high-precision calculation, which only needs the coordinates of 3D Attention is focused on fully automatic camera calibration, and a calibration method based on three-dimensional (3D) reference points is proposed. This method acquires camera parameters through three steps: automatic recognition, automatic matching and high-precision calculation, which only needs the coordinates of 3D points and the image. The method of calibration and the focal length coherence automatic matching algorithm are put forward under the condition of knowing the coordinates of camera center and the orientation of camera optical axis, respectively; and the minimal residual automatic matching algorithm is proposed using computation residual and reprojection residual as criterion, when there is no prior information. Numerical simulation and physical experimental results show the speediness, correctness and high precision of our automatic matching algorithms and fully automatic calibration model..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 612007 (2013)
Mirror Reflectance Spectrum Modeling of Smooth Samples
Zou Xiren, Bai Lu, and Wu Zhensen
Based on the reflectance spectrum measured data obtained by ellipsometer, we analyse and combine the advantages of different models of smooth samples. A reflectance spectrum model for smooth samples is proposed. The different samples in various of bands are fitted, and the parameter values and the root mean square erroBased on the reflectance spectrum measured data obtained by ellipsometer, we analyse and combine the advantages of different models of smooth samples. A reflectance spectrum model for smooth samples is proposed. The different samples in various of bands are fitted, and the parameter values and the root mean square error correspondingly are analyzed. It proves that this model may fit the spectral data of smooth samples. To explore the correctness of the model, it is compared with the five-parameter bidirectional reflectance distribution function (BRDF) model. The model integration in the upper half space is compared with the measured hemispheric anti-rate data of the samples. The results show that the model satisfies both reciprocity and energy conservation law, and it could ideally replace BRDF model for smooth samples..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 612008 (2013)
Method for Improving the Accuracy of S-Transform Profilometry
Shen Qiuju, Chen Wenjing, Zhong Min, and Su Xianyu
S Transform combines the advantages of the windowed Fourier transform and the wavelet transform. It is a kind of nondestructive and reversible time-frequency analysis method for the non-stationary signals with the characteristics of the linearity, multi-resolution and the only one inverse transformation existing. In adS Transform combines the advantages of the windowed Fourier transform and the wavelet transform. It is a kind of nondestructive and reversible time-frequency analysis method for the non-stationary signals with the characteristics of the linearity, multi-resolution and the only one inverse transformation existing. In addition, it has direct relationship with Fourier transform. Due to the shortage of the phase description based on the 1st-order Taylor expansion in the S transform “ridge” method, a more accuracy phase expression based on the 2nd-order Taylor expansion is proposed. According to the strictly theoretical analysis, a more accuracy calculation expression formula of the phase field is gotten and corresponding computer simulation and experiment are finished, which enriches the theory of S transform and improves the measurement accuracy of S transform. The three-dimensional (3D) reconstruction results based on the 1st-order Taylor expansion are also compared with that based on our method in S transform “ridge” method. The simulations and experiments show that the reconstruction of the surface from the 2nd-order Taylor expansion has higher measurement precision..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 612009 (2013)
Measurement Error Analysis for Mueller Matrix Based on a Single Photo-Elastic Modulator
Cao Shaoqian, Bu Yang, Wang Xiangzhao, Li Sikun, Tang Feilong, and Li Zhongliang
A measurement error equation and a relative error analysis method for the Mueller matrix measurement technique based on a single photo-elastic modulator are proposed. Considering the relative error and the condition number, two optimum angle sets for the quarter-wave plate are obtained, which diminish the maximum relatA measurement error equation and a relative error analysis method for the Mueller matrix measurement technique based on a single photo-elastic modulator are proposed. Considering the relative error and the condition number, two optimum angle sets for the quarter-wave plate are obtained, which diminish the maximum relative error of each element of the Mueller matrix. The experimental results show that the maximum relative errors of each element of the Mueller matrix of the measured quarter-wave plate are 0.12% and 0.20% respectively by using the two optimum angle sets above. Compared to the maximum relative error of 0.83% of the traditional optimum angle sets {-90°,-45°,30°,60°} for the quarter-wave plate, the maximum relative errors of each element of the Mueller matrix of the measured quarter-wave plate are decreased by 85.54% and 75.90% respectively by using the two optimum angle sets above..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 612010 (2013)
Lasers and Laser Optics
Phase-Modulation-Combination Method for Generation of High Repetition Short Pulses
Wang Shiwei, Zheng Jun, Xue Li, and Xu Jianqiu
Phase-modulation-combination (PMC) method is researched for generation of high repetition short pulses. The method is simple and compact consisting of two photoelectric switches and two modulators, where two sub-pulses from the switches are modulated and combined interferentially, giving rise to a narrower pulse. The pPhase-modulation-combination (PMC) method is researched for generation of high repetition short pulses. The method is simple and compact consisting of two photoelectric switches and two modulators, where two sub-pulses from the switches are modulated and combined interferentially, giving rise to a narrower pulse. The processes of PMC methods with different phase modulation functions are simulated numerically, and optimizations among different compression results induced by various phase function are given. Furthermore, the experimental verification for the system function is supplied, and short pulse train with 1 GHz repetition rate and 60-ps pulse duration is generated..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 614001 (2013)
Amplification Properties of a Distribution Feedback Semiconductor Laser under Optical Injection and Its Application in Generating Microwave Signals
Xiong Jintian, Wang Rong, Pu Tao, Lu Lin, Fang Tao, Wei Zhihu, Zheng Jilin, and Xiang Peng
An standard commercialized fiber-pigtailed distribution feedback (DFB) semiconductor laser without internal isolator is chosen as the slave laser to study the amplification properties of a semiconductor laser under optical injection. A signal consisting of a carrier and two second order sidebands is used as a probe sigAn standard commercialized fiber-pigtailed distribution feedback (DFB) semiconductor laser without internal isolator is chosen as the slave laser to study the amplification properties of a semiconductor laser under optical injection. A signal consisting of a carrier and two second order sidebands is used as a probe signal, which is generated by a Mach-Zehneder modulator (MZM) biased at the maximum transmission point. The amplification properties of the slave DFB laser under different injection powers are measured by measuring the power of the resonantly amplified probe signal after photodetector. Relationship between the optimum detuning frequency at largest gain of -2nd order sideband and the gain of the carrier and the -2nd order sideband in different injection ratios is also investigated. Optical single sideband (SSB) signal with high sideband suppression (SSR) is achieved, and a microwave signal with doubled frequency of the local oscillator (LO) signal with a good signal to noise ratio (SNR) is generated after photodetector. It provides a new way to generate a high frequency microwave signal..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 614002 (2013)
Polarization Dynamics of an SOA-Based Fiber Ring with Polarization Feedback
Wang Chunhua, Li Li, Peng Lei, Yu Qingyang, Zhang Shenfei, and Liu Tao
The influence of the polarization feedback of the fiber ring on the dynamics of the isotropic semiconductor optical amplifier (SOA)-based fiber ring system is studied by theoretical simulation and experiment. It is found from simulation that a bistable orthogonal-polarization light under stationary can be realized by aThe influence of the polarization feedback of the fiber ring on the dynamics of the isotropic semiconductor optical amplifier (SOA)-based fiber ring system is studied by theoretical simulation and experiment. It is found from simulation that a bistable orthogonal-polarization light under stationary can be realized by a polarization feedback of a 90°-rotation, and a dynamically-depolarized polarization chaos under non-stationary can be realized by properly setting polarization feedback. Experimentally, such a orthogonal-polarization modulation light is observed and a dynamically-depolarized polarization chaos with dynamical degree of polarization less than 1% is obtained in a SOA fiber ring system. The experimental results are well consistent with the theoretical simulations..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 614003 (2013)
Analysis of Maximum Extractable Power of 2 μm Holmium-Doped Silica Fiber Lasers
Zhu Yadong, Zhou Pu, Zhang Hanwei, Wang Xiaolin, and Guo Shaofeng
We study the power limit of holmium-doped fiber lasers with the consideration of thermal effects, optical damage effect, brightness of pump source and nonlinear effects. Power limits and physical limits of holmium-doped silica fiber lasers in both pump regions (pumped with ytterbium-doped or thulium-doped laser source)We study the power limit of holmium-doped fiber lasers with the consideration of thermal effects, optical damage effect, brightness of pump source and nonlinear effects. Power limits and physical limits of holmium-doped silica fiber lasers in both pump regions (pumped with ytterbium-doped or thulium-doped laser source) are calculated. It is found that using both of the two pump regions, separately, based on current technical conditions, power limits of broad bandwidth holmium-doped fiber lasers are 29.9 kW and 70.2 kW, respectively. Limits to power now are, in fact, brightness of the pump sources, thermal lens effect and stimulated Raman scattering (SRS), and thus to improve the brightness of the pump sources is an effective method to promote high output power of holmium-doped fiber lasers. The situations of fiber lasers with single-frequency and strict single-mode operation are considered. At the same time, fiber laser pumped with a thulium-doped laser source has an advantage for achieving higher output power..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 614004 (2013)
Machine Vision
Monocular Measurement for Point Target with Parabolic Motion
Lü Yaowen, Wang Jianli, Cao Jingtai, Wang Haojing, and Liu Wei
Under the assumption of known intrinsic parameters, a novel monocular measurement method consisting of three stages is proposed for point target with parabolic motion. The gravity direction vanishing point is gained by computing the intersection of lines obtained by projecting the hanging lines in the image plane. The Under the assumption of known intrinsic parameters, a novel monocular measurement method consisting of three stages is proposed for point target with parabolic motion. The gravity direction vanishing point is gained by computing the intersection of lines obtained by projecting the hanging lines in the image plane. The conic obtained by projecting the parabolic trajectories is computed using Sampson approximation and the rotation matrix could be evaluated by using parabolic projective geometry properties. By computing the translation vector from world coordinate to camera coordinate using ground planar homography, the parabolic supporting planar homography is established and the three-dimensional (3D) coordinate of point target is determined. Experiments with simulated data as well as with real images show that the method is valid and feasible. The experimental results indicate that the proposed novel approaches are practical and simple..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 615001 (2013)
Multi-Modal Image Registration Based on Local Frequency Information Using Modified Simplex-Simulated Annealing Algorithm
Liu Xiaochun, Zhong Tao, Yu Qifeng, Zhang Xiaohu, Lei Zhihui, and Shang Yang
The major challenges in registration between multi-modal images are the non-homogeneous intensity variation and the partial scene changes. Two local frequency representations, namely mean local phase angle (MLPA) and frequency spread phase congruent (FSPC), are used to achieve representations invariant to both non-homoThe major challenges in registration between multi-modal images are the non-homogeneous intensity variation and the partial scene changes. Two local frequency representations, namely mean local phase angle (MLPA) and frequency spread phase congruent (FSPC), are used to achieve representations invariant to both non-homogeneous intensity variation and contrast reversal between multi-modal images. In addition, by using FSPC one can effectively emphasize the common structural information. An objective function is constructed to take full advantage of the two representations as well as allocate more confidences to the stable structures. Simplex-simulated annealing algorithm is adjusted to avoid being trapped in local optima. Numerous experiments using real and synthetic images clearly demonstrate that the proposed method can effectively register multi-modal images with significant variation in geometric distortion, non-homogeneous intensity and scene, as well as, improve the registration accuracy and robustness of the conventional methods..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 615002 (2013)
One-Dimensional Multi-Camera Calibration Based on Fundamental Matrix
Fu Zhongliang, Zhou Fan, Xie Yanfang, and Qin Yong
With analyzing the defect of the methods based on vanishing point with radial distortion, a calibration algorithm is proposed. The fundamental matrix of binocular set is estimated, which allows to perform a projective calibration of each camera. The calibration is updated for the Euclidean space. The calibration is posWith analyzing the defect of the methods based on vanishing point with radial distortion, a calibration algorithm is proposed. The fundamental matrix of binocular set is estimated, which allows to perform a projective calibration of each camera. The calibration is updated for the Euclidean space. The calibration is possible without imposing any restriction on the movement of the pattern and without any prior information about the cameras or calculating vanishing point. It can calibrate all the cameras at the same time. This method is suitable for the fast camera calibration in a non-laboratory environment. Finally, the experiments on synthetic images validate that the proposed method is superior to the calibration method based on the vanishing point when the radial distortion cannot be ignored. The experiments on real images show that its accuracy makes it suitable for practical applications..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 615003 (2013)
Materials
Negative Refraction and Imaging Properties of Uniaxial Crystal Slabs
Du Yinxiao, Zhang Youlin, Ma Huali, Yuan Qingxin, and Xu Pei
Negative refraction and imaging properties of uniaxial crystal slabs are investigated by the refractive index ellipsoid analyses. It is found that the concept of negative refraction can be extended to be an intrinsic property of all uinaxial crystals. The negative refraction effect of uinaxial crystals is mainly due toNegative refraction and imaging properties of uniaxial crystal slabs are investigated by the refractive index ellipsoid analyses. It is found that the concept of negative refraction can be extended to be an intrinsic property of all uinaxial crystals. The negative refraction effect of uinaxial crystals is mainly due to the anisotropic refractive index. The angular range for incident light to yield negative refraction attains its maximum which only depends on the difference of two refractive indices and the orientation of the crystals with their optic axes at a certain angle to the normal of the light incoming surface. The negative refraction imaging of uniaxial crystal slabs is restricted within some special conditions. These conclusions are verified by the experiments on positive uniaxial crystal YVO4 and negative unaxial crystal CaCO3..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 616001 (2013)
Medical Optics and Biotechnology
Hemoglobin Diffuse Optical Tomography for Breast Tumor Diagnosis: Phantom Experiment and in Vivo Evaluation
Zhang Wei, Lu Yiming, Wu Linhui, Gao Feng, and Zhao Huijuan
A time-resolved hemoglobin-diffuse optical tomography (DOT) system is proposed for the early breast tumor optical measurements, which is developed to produce functional images of the female breast. The system applies time-correlated single photon counting method to acquire the time-resolved light distributions of the lA time-resolved hemoglobin-diffuse optical tomography (DOT) system is proposed for the early breast tumor optical measurements, which is developed to produce functional images of the female breast. The system applies time-correlated single photon counting method to acquire the time-resolved light distributions of the light re-emissions from the boundaries. To keep the balance between detection time and hardware cost, a combined framework made up of four-channel parallel-detecting module and optical switches is used, which could decrease the influence of channels′ attenuation differences and reduce the interference arising from the artifacts. The simultaneous reconstructions of the two optical (absorption and scattering) properties are achieved with the respective featured-data algorithms based on the generalized pulse spectrum technique. The performances of the methodology are assessed on breast-mimicking phantom and pilot experiments. The results demonstrate the efficacy of the hemoglobin-DOT for breast tumor diagnosis that the optical parameters can be reconstructed simultaneously, and the corresponding function information is useful for early breast tumor diagnosis..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 617001 (2013)
Pilot Investigation into Shape-Based Diffuse Optical Tomography Methodology with Spherical Harmonics Parameterization
Wu Linhui, Zhao Huijuan, Yi Xi, Zhang Wei, and Gao Feng
A shape-based approach of image reconstruction under continues-wave mode is developed for diffuse optical tomography (DOT), which aims to simultaneously recover the smooth region boundaries and optical parameters of the biological tissue. The method is based on the spherical harmonics parameterization methodology and aA shape-based approach of image reconstruction under continues-wave mode is developed for diffuse optical tomography (DOT), which aims to simultaneously recover the smooth region boundaries and optical parameters of the biological tissue. The method is based on the spherical harmonics parameterization methodology and an assumption that different anatomical regions have their respective sets of the homogeneous optical parameter distributions. The boundary element method (BEM) is used for forward modeling, and a Levenberg-Marquardt optimization method is implemented for the inverse problem. The proposed scheme is validated using a domain with two heterogeneous inclusions, the shape parameters and the optical coefficients of the domains can be simultaneously reconstructing at different noise levels. And physical experiment on a phantom is also conducted to evaluate the performance of our method. The reconstructed results show that the methodology is very promising and of good convergence. The homogeneous optical parameters and shape parameters of each region can be reconstructed with good accuracy..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 617002 (2013)
Research of Near-Infrared Small Living Animal Fluorescence Imaging System
Wang Mao, Li Chunyan, Sun Yunfei, Li Min, Zhai Xiaomin, and Wu Dongmin
Small animal fluorescence imaging system is an important tool in life sciences and medicine research because of its in vivo and noninvasive imaging ability. But the relative low penetration depth of the visible light of existing small animal imaging systems, as well as the relative low signal-to-noise, prevents this teSmall animal fluorescence imaging system is an important tool in life sciences and medicine research because of its in vivo and noninvasive imaging ability. But the relative low penetration depth of the visible light of existing small animal imaging systems, as well as the relative low signal-to-noise, prevents this technology from deep tissue imaging. Fluorescence single in the second near-infrared window (NIR II, 1000~1350 nm) could be utilized to improve the imaging depth due to the relative low tissue scattering. The presented work describes the design and performance evaluation of a near-infrared small animal fluorescence imaging system working in this particular spectrum window. Simulation experiments indicate that this imaging system achieves a relative high signal-to-noise ratio (57 dB) and large penetration depth (deeper than 10 mm). Vascular networks and organ of the mouse are clearly visualized using this imaging system by injection of Ag2S quantum dots (QD) emitting at 1200 nm..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 617003 (2013)
Nonlinear Optics
Modulation Instability of Cross-Phase Modulation Induced by Cubic-Quintic Nonlinearity in Metamaterials
Liu Ying, Xu Chuanxi, Hu Zhihui, and Xue Yanling
Based on the dispersive Drude model in metamaterials, nonlinear coupled Schrdinger equations are derived for two copropagating optical waves with cubic-quintic nonlinearity and modulation instabilities induced by the cross-phase modulation (XMI) are studied. The impact of quintic nonlinearity on the gain spectra of XMBased on the dispersive Drude model in metamaterials, nonlinear coupled Schrdinger equations are derived for two copropagating optical waves with cubic-quintic nonlinearity and modulation instabilities induced by the cross-phase modulation (XMI) are studied. The impact of quintic nonlinearity on the gain spectra of XMI is analyzed. It shows that the quintic nonlinearity strengthens the XMI with broader XMI spectra and higher peak gain. It is found that the XMI gain is obviously larger in the region with abnormal group velocity dispersion (GVD) than that in the region with normal GVD. Two cases with or without the group velocity mismatch (GVM) in XMI are compared and the GVM is found to play an important role in the occurrence of XMI. It also shows that the serious XMI occurs when two optical waves propagate simultaneously in the positive refractive index region or in different refractive index regions..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 619001 (2013)
Optical Design and Fabrication
Design of All Spherical Surfaces Zoom Lithographic System
Lü Bo, Liu Weiqi, Kang Yusi, Feng Rui, Liu Hua, and Wei Zhonglun
A zoom functional optical lithography system with all spherical surfaces is designed. The system can automatically realize four zoom positions, and is comprised of two negative lens working as zoom group, two positive lens working as compensatory group to compensate the image surface shift induced by the conjugate distA zoom functional optical lithography system with all spherical surfaces is designed. The system can automatically realize four zoom positions, and is comprised of two negative lens working as zoom group, two positive lens working as compensatory group to compensate the image surface shift induced by the conjugate distance change during the zooming motion. The system has an optical length of 653.67 mm with 22 pieces of lens. All the components are spherical surface and no special glass is employed. Under the 405 nm working wavelength, the modulation transfer function of this up-to-date lens is greater than 0.4 with 500 lp/mm at all four zooming positions and field of view and the absolute distortion is less than one sixth characteristic dimension. The result illuminates that the lens system design meets the requirement of good image quality and low cost for manufacture, and it can be applied in micrometer solution zoom optical lithography system..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 622001 (2013)
Polarization Aberration Compensation Method for Lithographic Projection Lens Based on a Linear Model
Tu Yuanying, and Wang Xiangzhao
Based on a linear model, a novel method to compensate the polarization aberration of lithographic projection lens is proposed. By using the Hopkins vector theory of partially coherent imaging, the analytical expressions of the aerial image, as well as the image placement error (IPE) and the best focus shift (BFS) inducBased on a linear model, a novel method to compensate the polarization aberration of lithographic projection lens is proposed. By using the Hopkins vector theory of partially coherent imaging, the analytical expressions of the aerial image, as well as the image placement error (IPE) and the best focus shift (BFS) induced by the polarization aberrations are derived for the alternating phase-shift mask (Alt-PSM) grating pattern. Based on these analytical expressions, a linear relation model is established between the polarization aberration and the image quality (IPE, BFS). By calculating the polarization aberration linear sensitivities and adjusting the scalar aberrations based on the linear model, the adverse influences of the polarization aberrations on image guality can be minimized, i.e., realizing polarization aberration compensation. The compensation accuracies are dependent on the scalar aberration adjustment accuracy of the projection lens and the sensitivity of the grating pattern to the scalar aberration. The simulation results show that the IPE and the BFS difference of the gratings with different pitches can be effectively reduced, and the image quality can be improved by the polarization aberration compensation method..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 622002 (2013)
A Common-Path Radial Shearing Phase-Shifting Interferometer with Adjustable Fringe Contrast
Liu Yao, Bai Fuzhong, Wu Yaqin, Gan Shiming, Liu Zhen, and Bao Xiaoyan
A common-path radial shearing phase-shifting interferometer with adjustable fringe contrast is proposed against some disadvantages of conventional one, such as non-adjustable fringe contrast, low measurement accuracy of shearing phase difference recovery or complicated phase-shifting method, and difficulty of optical sA common-path radial shearing phase-shifting interferometer with adjustable fringe contrast is proposed against some disadvantages of conventional one, such as non-adjustable fringe contrast, low measurement accuracy of shearing phase difference recovery or complicated phase-shifting method, and difficulty of optical system adjustment. The contrast adjusted continuously is achieved using polarization beam splitters in this system, and the four-stepping phase-shifting interference is also carried out by the polarization phase-shifting technology. The fringe contrast which is one of the main influence factors about wavefront reconstruction accuracy is analyzed theoretically and verified experimentally. The actual aberration generated by liquid crystal spatial light modulator (LC-SLM) is measured experimentally. The results indicate that the common-path radial shearing phase-shifting interferometer can gain the highest fringe contrast. The research results of the relationship between the polarizing angle and fringe contrast can provide an important theoretical basis for the design and establishment of related optical systems..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 622003 (2013)
Design of Infrared Athermal Optical System for Dual-Band with Double-Layer Harmonic Diffraction Element
Zhang Xinting, and An Zhiyong
An infrared athermal optical system with F number of 1.2 for dual-band of 3~5 μm and 8~12 μm is designed. In this system, the view of vision angle is 22°, total length is 78 mm. Germanium and AMTIR I (mix of Ge, As and Se) and double-layer harmonic diffraction element are used to simplify the three-lens structure,An infrared athermal optical system with F number of 1.2 for dual-band of 3~5 μm and 8~12 μm is designed. In this system, the view of vision angle is 22°, total length is 78 mm. Germanium and AMTIR I (mix of Ge, As and Se) and double-layer harmonic diffraction element are used to simplify the three-lens structure, decrease weight, and improve the quality of the imaging. Across temperature range of -40 ℃~60 ℃, the system has a stable performance and applies to gaze-type dual-band focal plane array detector with pixel size of 25 μm, and pixel number of 640 pixel×480 pixel. The design results show that, the modulation transfer function (MTF) is greater than 0.5 at different temperatures when the Nyquist frequency of detector is 20 lp/mm. The imaging quality is good, and athermal design is realized. It can distinguish a target of 3 m when the distance is 2 km. So this system can meet the needs of military reconnaissance..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 622004 (2013)
Optical Design of Decentered Aperture-Divided Polarization Imaging System
He Hucheng, Ji Yiqun, Zhou Jiankang, Zhao Zhicheng, and Shen Weimin
Design method of an aperture-divided optical system used for polarization imaging systems is introduced and discussed in detail. Aperture-divided optical system is a decentered optical system composed of several coaxial subsystems. Its primary aberrations are represented based on the primary aberration theory. The initDesign method of an aperture-divided optical system used for polarization imaging systems is introduced and discussed in detail. Aperture-divided optical system is a decentered optical system composed of several coaxial subsystems. Its primary aberrations are represented based on the primary aberration theory. The initial structure parameters are calculated with the PW method and least square algorithm. A four sub-aperture optical system with effective focal length of 40 mm, F-number of 4.5 and wavelength range from 450 nm to 650 nm is optimized. The system uses an ordinary optical glass with total optical length of 120 mm. Imaging performances of the designed system approache to diffraction-limited and can meet the application requirements of the polarization imaging..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 622005 (2013)
Design Method of an Aerial Conformal Optical Window
Zhang Peng, Zhao Chunzhu, and Cui Qingfeng
The outside surface shape of the aerial conformal optical window is determined by the aerodynamic requirement and is often an asymmetric free-form surface which produces a large number of aberrations. The aberrations can be reduced by appropriate inner surface shape of conformal window after design and optimization. ThThe outside surface shape of the aerial conformal optical window is determined by the aerodynamic requirement and is often an asymmetric free-form surface which produces a large number of aberrations. The aberrations can be reduced by appropriate inner surface shape of conformal window after design and optimization. The characteristics of free-form surface which is applied to the conformal optical window are studied. The specific design method of aerial conformal optical window is given. The conformal optical windows are designed for corresponding medium-wave infrared optical systems which are placed behind them. And the design results show that the conformal optical windows through design and optimization with this method reduces the aberrations in large quantities produced by the free-form outside surface. And the conformal optical windows have small influence on the image quality of corresponding optical systems when these optical systems are placed behind the corresponding conformal optical windows..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 622006 (2013)
Optical Devices
Design and Modes of a Novel Two-Dimensional Microscanner with Electrostatic Actuation
Liu Yaobo, Yuan Weizheng, Qiao Dayong, Yang Xuan, Liang Xiaowei, and Lian Bin
A novel two-dimensional microscanner with electrostatic actuation is designed and fabricated based on silicon-on-insulator (SOI) technology, and the driving principle is analyzed for microscanner. Then the finite element analysis software of ANSYS is used to simulate the models of the first five orders, and the methodsA novel two-dimensional microscanner with electrostatic actuation is designed and fabricated based on silicon-on-insulator (SOI) technology, and the driving principle is analyzed for microscanner. Then the finite element analysis software of ANSYS is used to simulate the models of the first five orders, and the methods to calculate the resonant frequencies are analyzed for expected torsional modes theoretically. The resonant frequencies are measured by laser Doppler vibrometer. The results show that the microscanner could oscillate at the inherent frequencies of 402 Hz and 1218 Hz around the two rotational axes, which are consistent with the simulation results. The slight difference is caused by factors such as the model without comb structures, air damping and environmental temperature. This study is meaningful to design a microscanner actuated electrostatically with simpler structure..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 623001 (2013)
Response Characteristic of Blue Light-Emitting Diodes
Su Chen, Chen Guichu, Zheng Shuwen, He Longfei, Pi Hui, Xu Yiqin, Tong Jinhui, and Fan Ganghan
The impulse response characteristics and modulation bandwidth of blue light-emitting diode with a special-designed AlGaN staircase electron blocking layer are investiggated by using square wave pulse and sine wave modulation methods. And the energy band diagrams of the blue light-emitting diode (LED) with this special-The impulse response characteristics and modulation bandwidth of blue light-emitting diode with a special-designed AlGaN staircase electron blocking layer are investiggated by using square wave pulse and sine wave modulation methods. And the energy band diagrams of the blue light-emitting diode (LED) with this special-designed staircase electron blocking layer have been numerically investigated using the APSYS simulation software. The simulation shows that ΔEc increases 43 meV and ΔEv decreases 36 meV. The results show that blue light-emitting diode with a special-designed AlGaN staircase electron blocking layer has better light output power and response performance. The superior performance can be attributed to higher carrier injection density of the active region, which improves the electron/hole radiative recombination rate..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 623002 (2013)
Remote Sensing and Sensors
A Method on Measurement of Mueller Matrix Elements for Polarization Correction
Li Zhanfeng, Wang Shurong, Huang Yu, and Lin Guanyu
Errors caused by polarization sensitivity of remote sensing spectrometer must be reduced to meet the requirements of the reliability and precision of remote sensing data. The common method is the use of the depolarization and in-orbit polarization correction. This polarization correction method is introduced in theory.Errors caused by polarization sensitivity of remote sensing spectrometer must be reduced to meet the requirements of the reliability and precision of remote sensing data. The common method is the use of the depolarization and in-orbit polarization correction. This polarization correction method is introduced in theory. The overdetermined equation, calibration formula of Mueller matrix elements required is deduced. By this formula, the Mueller matrix elements of ultraviolet ozone vertical profile probe are calculated. In combination with the results, the errors by the method are analysed and feasibility as well as precision is also validated..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 628001 (2013)
Atmospheric Boundary Layer Detected by a Fraunhofer Lidar over Qingdao Suburb
Zhang Wei, Wu Songhua, Song Xiaoquan, and Jin Lei
Lidar with high spatial and temporal resolution detects atmospheric parameters by receiving the echo signal signal. Because of the disturbance of strong solar background light, the signal-to-noise ratio (SNR) of lidar in the daytime is greatly restricted so that the atmospheric parameters and characteristics of the atmLidar with high spatial and temporal resolution detects atmospheric parameters by receiving the echo signal signal. Because of the disturbance of strong solar background light, the signal-to-noise ratio (SNR) of lidar in the daytime is greatly restricted so that the atmospheric parameters and characteristics of the atmospheric boundary layer are hardly observed with consistent quality through day and night. The photon counting lidar prototype in Fraunhofer dark lines is devised to solve this problem. The atmospheric boundary layer of Qingdao suburb is observed using the lidar. The SNR is improved 2~3 times by operating the lidar at the wavelength of solar dark lines. The extinction coefficient obtained by inversion of the detected data illustrates the vertical structures of aerosol in the atmospheric boundary over Qingdao suburb during summer 2011..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 628002 (2013)
Real-Time Line of Sight Calibration Algorithm for High Earth Orbit Infrared Scanning Sensor
Xue Yonghong, An Wei, Zhang Tao, and Zhang Yinsheng
Line of sight (LOS) calibration is the key precondition of accurate location and tracking of targets in infrared surveillance systems and the LOS calibration of scanning sensor is one of the difficulties. Based on the analysis of the imaging model and characteristics of scanning sensor, a theoretical calibration model Line of sight (LOS) calibration is the key precondition of accurate location and tracking of targets in infrared surveillance systems and the LOS calibration of scanning sensor is one of the difficulties. Based on the analysis of the imaging model and characteristics of scanning sensor, a theoretical calibration model based on the estimation of mismatching angles is proposed. By establishing the process model of the mismatching angles and the observation model of sensor LOS, and using an unscented Kalman filter (UKF), the real time estimation of mismatching angles and calibration of sensor LOS are finally achieved. Simulation results show that the proposed algorithm has a high precision and smooth performance for sensor LOS calibration, and can effectively improve the timeliness and precision of target tracking process in infrared surveillance system..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 628003 (2013)
Scattering
Abnormal Moving of Scattered Energy Distribution and Its Effect on Particle Size Analysis
Ge Baozhen, Pan Linchao, Zhang Fugen, and Wei Yaolin
Laser particle sizer which based on Mie scattering theory is one of the most widely used instruments in particle size measurement. Generally the smaller the particles are, the bigger the scattering angle is. The main peak position of Mie scattered energy distribution received by the detector array moves outward. HoweveLaser particle sizer which based on Mie scattering theory is one of the most widely used instruments in particle size measurement. Generally the smaller the particles are, the bigger the scattering angle is. The main peak position of Mie scattered energy distribution received by the detector array moves outward. However, for some particles of relative index of refraction in certain size ranges, the main peak position of scattered energy distribution moves toward the inside of the detector array as the particle size decreases, which can be called the abnormal moving of scattered energy distribution. Based on Mie scattering theory, the patterns of such abnormal moving and abnormal particle size interval of different relative indexes of refraction are obtained, the effect on particle size analysis is analysed, a method to reduce the effect is proposed. An actual sample is measured and compared. The results show that this method can reduce the effect of abnormal moving on particle size analysis..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 629001 (2013)
Spectroscopy
Realization of Narrow Linewidth Fluorescence Spectrum of Strontium Intercombination Transition and Analysis of Its Line Broadening Factors
Liu Hui, Ren Jie, Tian Xiao, and Chang Hong
The strontium (5s2)1S0-(5s5p)3P1 intercombination transition is characterized far narrower natural line width than its counterpart dipode transition line (5s2)1S0-(5s5p)3P1 and has been applied in the field of optical frequency standards. In order to obtain its high quality spectrum, the line broadening factors of stroThe strontium (5s2)1S0-(5s5p)3P1 intercombination transition is characterized far narrower natural line width than its counterpart dipode transition line (5s2)1S0-(5s5p)3P1 and has been applied in the field of optical frequency standards. In order to obtain its high quality spectrum, the line broadening factors of strontium (5s2)1S0-(5s5p)3P1 intercombination transition fluorescence spectrum are theoretically analyzed based on thermal atomic beam collimated by capillary tubes. The factors, including Doppler effect, laser line width, saturation broadening and transit-time broadening, are considered. Experimentally, the fluorescence spectrum including the saturated fluorescence spectrum, is obtained from the differently collimated strontium thermal atomic beams. The exprimental results show that the higher collimated thermal beam′s fluorescence spectrum line width is only 6.5 MHz, which is on the same order of magnitude as the Lamb-dip line width in the saturated fluorescence spectrum (1.7 MHz), and greatly reduces first-order Doppler broadening of spectra. And an external cavity diode laser is locked to the narrow line fluorescence spectrum by modulating the laser′s frequency directly, achieving a laser line width of about 0.72 MHz..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 630001 (2013)
Thin Films
Accurate EPMA/WDS Measurement of Aluminium Composition in AlxGa1-xN Crystal Film
Liu Yunchuan, Zhou Yanping, Wang Xuerong, Meng Xiangyan, Duan Jian, and Zheng Huibao
The motion tracks of high energy accelerated electron in AlxGa1-xN crystal film material are simulated by Monte Carlo method, The relationships between accelerated voltages and the depths which kV voltages accelerated electron can reach are studied. The experimental thickness of crystal film epitaxial layer is measuredThe motion tracks of high energy accelerated electron in AlxGa1-xN crystal film material are simulated by Monte Carlo method, The relationships between accelerated voltages and the depths which kV voltages accelerated electron can reach are studied. The experimental thickness of crystal film epitaxial layer is measured by ultraviolet visible light transmittance spectra method. The aluminium composition of crystal film epitaxial layer is determined by electron probe microanalysis/wavelength dispersive spectrometer (EPMA/WDS) method, with suitable experimental parameters of accelerated voltage and current and beam diameter from theoretical simulation. The experiment is carried out between two EPMA laboratories, six samples by each laboratory. The source of measurement uncertainty is analyzed including measurement reproducibility and X-ray intensity and physical parameter etc.. The experimental results show that the measurement uncertainty of EPMA/WDS for the determination of aluminium composition (x=0.8) is 2.7×10-2, the coverage factor k is 2..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 631001 (2013)
Preparation and Property of Antireflective Complex Structures on Multicrystalline Silicon Surface
Zhang Lidian, Shen Honglie, and Yue Zhihao
By combining nitric acid etching and Ni-assisted etching, the antireflective complex structure on multicrystalline silicon surface is prepared. Effects of the sputtering time of Ni on the performances including surface reflectance, morphology and photoluminescence property are studied. The surface reflectance of the muBy combining nitric acid etching and Ni-assisted etching, the antireflective complex structure on multicrystalline silicon surface is prepared. Effects of the sputtering time of Ni on the performances including surface reflectance, morphology and photoluminescence property are studied. The surface reflectance of the multicrystalline silicon wafers is analyzed by spectrophotometer. The morphologies are observed by scanning electron microscopy and the photoluminescence properties are analyzed by photoluminescence measurement system. It is found that U-shaped etching pits with many needle-like structures inside are formed after the combined nitric acid etching and Ni-assisted etching. The results show that this kind of complex microstructures can significantly reduce the surface reflectance. The minimum surface reflectance in the range from 300 nm to 900 nm is only 10.1% when the sputtering time of Ni is 500 s..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 33, Issue 6, 631002 (2013)
© Copyright 2018-2021 | Chinese Laser Press. All Rights Reserved 沪ICP备15018463号-20