Contents
2012
Volume: 32 Issue 6
50 Article(s)
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Detectors
Scene-Based Assessment Method for Nonuniformity of Infrared Focal Plane Array
Xie Xufen, Zhang Wei, Zhi Xiyang, Zhao Ming, and Wang Hongyuan
Aiming at quantitative assessment of nonuniformity of infrared focal plane array (IRFPA), a scene-based assessment method is researched. First of all, distribution characteristics of remote sensing image sequence are analyzed by real remote data, an assessment method by constructing standard image based on sequence sorAiming at quantitative assessment of nonuniformity of infrared focal plane array (IRFPA), a scene-based assessment method is researched. First of all, distribution characteristics of remote sensing image sequence are analyzed by real remote data, an assessment method by constructing standard image based on sequence sorting and wavelet transform is proposed for small image sequence. Then, combined past assessment method for nonuniformity, response nonuniformity of constructed standard image is proposed. Finally the algorithm of construction standard image is verified by blackbody radiometric calibration method (BRCM) and statistical method separately. And this assessment method for nonuniformity is used in image sequence using different scene-based nonuniformity correction. The experimental results show that for the standard images constructed by two groups of image sequences of 128 frame, the nonuniformity calculated by new method is 0.92% less than that of BRCM, and 0.59% more than that of statistical method, respectively. This assessment method can assess the nonuniformity of infrared remote sensing image..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 604001 (2012)
Polynomial Correction of Photon-Counting Position-Sensitive Detector′s Distortion
He Lingping, Yue Jinying, Liu Shijie, and Chen Bo
The polynomial correction method is used to correct photon-counter position-sensitive detector′s distortion. The principle of these detectors is introduced and the causes of distortion are analyzed. Based on the theory of polynomial distortion correction, its correcting process in photon-counter position-sensitive deteThe polynomial correction method is used to correct photon-counter position-sensitive detector′s distortion. The principle of these detectors is introduced and the causes of distortion are analyzed. Based on the theory of polynomial distortion correction, its correcting process in photon-counter position-sensitive detector has been proposed. According to this process, two photon-counting detectors based on a wedge-strip anode with different parameters are corrected, and the residual distortions are respectively 2.5 pixel and 1.2 pixel. The correction results show that polynomial distortion correction can be effectively applied to correction of photon-counter position-sensitive detector′s imaging distortion..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 604002 (2012)
Fiber Optics and Optical Communications
Reflection Spectrum Characteristics of the Grapefruit-Type Photonic Crystal Fiber Chirped Grating
Bi Weihong, Li Jianping, and Qi Yuefeng
Based on the finite element method and transmission-matrix method, the reflection spectrum of the grapefruit-type photonic crystal fiber chirped grating is analyzed theoretically. The influences of the fiber grating parameters and fiber structural parameters on the reflection spectrum characteristics of the photonic crBased on the finite element method and transmission-matrix method, the reflection spectrum of the grapefruit-type photonic crystal fiber chirped grating is analyzed theoretically. The influences of the fiber grating parameters and fiber structural parameters on the reflection spectrum characteristics of the photonic crystal fiber chirped grating are analyzed. The results show that with the increase of the chirp coefficient and refractive indexes modulation, the reflection spectrum changes regularly. When the chirp coefficient increases to a certain extent, the several reflection peaks can be connected together to form a large reflection band. The spacing between the reflection peaks can be changed by the inner-cladding diameter and the core diameter of the photonic crystal fiber. At the same time, the influence of apodization on reflection spectrum of the photonic crystal fiber chirped grating is discussed. Studies show that the apodization function can apodize several peaks and the apodization effect of each peak is very good. For fiber grating with several peaks connected, the wave of its reflection spectrum is large. But through the Cauchy apodization, the reflection spectrum curve is smooth, which is suitable for practical applications..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 606001 (2012)
Analysis and Experimental Research on Bit Error Rate for Free-Space Optical Communication Systems through Turbulent Atmosphere
Li Fei, Wu Yi, and Hou Zaihong
Performance of free-space optical communication (FSO) system fluctuates greatly due to influence by atmospheric turbulence. Research about evaluating system error performance according to parameters of system and atmosphere is a subject of current interest. Based on both optical turbulence channel and photoelectric detPerformance of free-space optical communication (FSO) system fluctuates greatly due to influence by atmospheric turbulence. Research about evaluating system error performance according to parameters of system and atmosphere is a subject of current interest. Based on both optical turbulence channel and photoelectric detection model, a mathematic simulation model of error performance for FSO system is established, and an expression of bit error rate for FSO system through turbulent atmosphere is proposed. Results of simulation are compared with experimental data obtained under weak turbulence condition and the model is used to characterize factors in turbulence, such as intensity fluctuation and background noise, etc. Simulation results are shown to be consistent with experimental data, intensity fluctuation is a chief factor of system performance fluctuation, and optimized threshold should be adjusted according to pratical atmosphere. The presented model can lead to an efficient performance evaluation and provide reference to correlative theoretical researches..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 606002 (2012)
Fourier Optics and Signal Processing
Theoretical Analysis of Photolithography Alignment and Calibration Method Based on Moiré Fringes
Zhu Jiangping, Hu Song, Yu Junsheng, Tang Yan, and Zhou Shaolin
To realize the calibration of grating direction and alignment between mask and wafer, on the basis of theory of line grating used for photolithography alignment, a novel method for eliminating angular displacement using phase slope is proposed. Line grating masks and their alignment principle are also given. Before aliTo realize the calibration of grating direction and alignment between mask and wafer, on the basis of theory of line grating used for photolithography alignment, a novel method for eliminating angular displacement using phase slope is proposed. Line grating masks and their alignment principle are also given. Before alignment, there exists angular displacement between mask alignment marks and wafer alignment masks. The nature of Moiré fringes and their relation with physical parameters of grating are mainly discussed, and the corresponding calculation formulas are obtained. According to Fourier method of frequency domain, relation between Moiré fringe frequency components and stripes is briefly analyzed. Using extracted one dimensional phase of Moiré fringes in ranks, inner relation between phase slope and angular displacement is obtained by data fitting, and calibration of stripe direction is realized. Simulation experimental results show that this method is simple and reliable, minimum angular displacement with less than 0.02° can be identified..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 607001 (2012)
Tolerance Analysis for a Static Fourier-Transform Infrared Spectrometer Based on Multi-Micro Mirrors
Fu Jianguo, Liang Jingqiu, and Liang Zhongzhu
The spectral noises or spectral resolution is the main criterion for spectrometer, but it is not suitable for tolerance analysis and optical optimization. Therefore, the system is divided into three sub-systems: the front optical system, the interferometer and the post optical system, and three different criterions areThe spectral noises or spectral resolution is the main criterion for spectrometer, but it is not suitable for tolerance analysis and optical optimization. Therefore, the system is divided into three sub-systems: the front optical system, the interferometer and the post optical system, and three different criterions are taken separately. Wavefront errors is taken as criterion by the front optical system, and then the relationship between wavefront errors and spectral noises is analysed. If the changes in wavefront errors by the manufacturing and alignment errors are calculated, the influence on system performance could also be evaluated. Spectral noises can be taken as criterion by the interferometer, and the changes in system performance is evaluated directly. The spot diameter is taken as the criterion by the post optical system. Through this way, the sensitivity for three sub-systems and the tolerance tables on the front and post optical systems are listed..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 607002 (2012)
[in Chinese]
[in Chinese]
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 636001 (2012)
Holography
Space-to-Time Conversion by Femtosecond Spectrum Holography
Cao Lan, Yan Xiaona, Dai Ye, and Yang Xihua
Based on spectrum holography structure proposed by Mazurenko, an improved femtosecond spectrum holography structure is proposed. The recording and readout of the spectrum holography by femtosecond pulses with both the spatial and temporal information is deduced, it shows if a filter is put on the spectrum plane of the Based on spectrum holography structure proposed by Mazurenko, an improved femtosecond spectrum holography structure is proposed. The recording and readout of the spectrum holography by femtosecond pulses with both the spatial and temporal information is deduced, it shows if a filter is put on the spectrum plane of the modified structure, spatial information included in the femtosecond pulse can be converted in to temporal information and output. The results can be applied in many fields, such as ultrashort pulse shaping, ultrafast optical communication and optical information processing etc..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 609001 (2012)
Improved Fienup′s Iteration Method for Image Reconstruction in Digital Holography
Pan Xingchen, Liu Cheng, and Zhu Jianqiang
In order to distinguish real image from conjugate image and zero-order term in digital hologram, a new method of image reconstruction is proposed. This method using the theory of coherent diffraction imaging (CDI) reconstructs accurate image without zero-order diffraction and conjugate image. The method proposed includIn order to distinguish real image from conjugate image and zero-order term in digital hologram, a new method of image reconstruction is proposed. This method using the theory of coherent diffraction imaging (CDI) reconstructs accurate image without zero-order diffraction and conjugate image. The method proposed includes two processes: the first is to measure the object intensity distribution, the hologram and the reference light intensity distribution; the second is the reconstruction of object by using computer. The convergence speed and image quality are improved because of the coherent light. Basic principle and simulation result are described. And the experiment of image reconstruction of biological sample plates is carried out..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 609002 (2012)
Imaging Systems
Multi-Target Threat Assessment of the Infrared Fisheye System
Zhou Yulong, He Yongqiang, and Zhang Weian
When the target is several miles away from the infrared fisheye system, it will be a point target in the infrared image, so there is no target information of distance, geometry and texture, without which it is hard to assess the threat of target accurately. So the multi-target threat assessment of infrared fisheye systWhen the target is several miles away from the infrared fisheye system, it will be a point target in the infrared image, so there is no target information of distance, geometry and texture, without which it is hard to assess the threat of target accurately. So the multi-target threat assessment of infrared fisheye system is studied. A multi-target threat assessment model of the infrared fisheye system is proposed. In the model, the distance and the radial velocity of each hour are derived from the initial distance taken by laser range finder, and hence the multi-target threat assessment model is established including the threat factors of target distance, radial velocity, course angle and angular altitude. Then considering the nonlinear characteristic of multi-target threat assessment, the radial basis function (RBF) neural network is used to solve the problem for its good self-adaptive and self study ability to solve nonlinear complex problems and the training sample generation is also discussed. After simulation experiment, it is found that this method is feasible and effective..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 611001 (2012)
Photoacoustic Tomography of Multi-Layer Sample Using Acoustic Lens
Wei Yadong, Wu Yunxia, and Zhang Zhijian
When a short laser pulse illuminates the virtual absorber in a scattering medium, the absorber will generate pressure distribution which is linearly proportional to the optical absorption of the medium. The laser induced ultrasonic signals are imaged with an acoustic lens. A 64-element linear transducer array is one-diWhen a short laser pulse illuminates the virtual absorber in a scattering medium, the absorber will generate pressure distribution which is linearly proportional to the optical absorption of the medium. The laser induced ultrasonic signals are imaged with an acoustic lens. A 64-element linear transducer array is one-dimensionally scanned on an imaging plane to acquire the acoustic pressure distribution by high speed acquisition card, and the signals are recorded and reconstructed by a computer. A new fast photoacoustic tomograph imaging system is demonstrated. It can acquire and record the data for a certain depth. The system can reconstructe different images from different planes at the same time only by selecting different numbers of columns in the datasheet. We experimentally obtain photoacoustic tomography images on different planes in the scattering media successfully. The images are vivid and contrast clearly with the background. This method directly provides images on different object planes of absorbing structures at the same time without the need of computational reconstruction..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 611002 (2012)
Instrumentation, Measurement and Metrology
Analysis of the Spectral Characters of Terahertz-Wave
Kang Shengwu, Wang Jiping, Liu Kan, Zhang Xinyu, Xie Changsheng, and Zhang Tianxu
At present, terahertz technology research mainly concentrates in its generation and detection mechanism. As the terahertz-wave being in the frequency range between microwave and visible light, whether the microwave and optical theory is applicable to terahertz-wave or has some common characteristic is to be studied. AnAt present, terahertz technology research mainly concentrates in its generation and detection mechanism. As the terahertz-wave being in the frequency range between microwave and visible light, whether the microwave and optical theory is applicable to terahertz-wave or has some common characteristic is to be studied. Analyzing and verifing the terahertz-wave field amplitude obeys the Gaussian distribution in the receiving plane perpendicular to the direction of propagation in the air medium by experiment; measurement brings forward energy distribution chart of terahertz wave in the air medium; the energy attenuation formulas of terahertz wave is deduced on the basis of the experimental data; the terahertz wavelength apparatus is designed using the Fabry-Perot (F-P) interferometer theory; the wavelength of emitted wave between 1~3 THz is measured from the SIFIR-50 THz laser of American Corehent Company. The related factors affecting the measurement precision including far-field divergence angle, the beam incident angle, mechanical vibration, temperature fluctuation and the refractive index fluctuation is analyzed at last..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 612001 (2012)
Numerical Research on Perturbation Reconstruction Theory of Chirped Pulse Spectral Interferometry
Fan Wei, Wu Yuchi, Xin Jianting, Dong Jun, Ao Guanghong, Zhao Zongqing, Cao Leifeng, Zhang Xueru, Wang Yuxiao, and Gu Yuqiu
Using chirped pulse spectral interferometry, single-shot diagnosis of ultrafast optical transient process can be achieved. The temporal resolution is determined by spectral width while the temporal measuring range is determined by pulse width, and they are both affected by the spectrometer′s work performance. After twoUsing chirped pulse spectral interferometry, single-shot diagnosis of ultrafast optical transient process can be achieved. The temporal resolution is determined by spectral width while the temporal measuring range is determined by pulse width, and they are both affected by the spectrometer′s work performance. After two linear chirped pulse enter into the spectrometer, the same spectral components will interfere to form spectral interference fringes. If one pulse is perturbed externally, the specific shape of perturbation can be reconstructed according to interference fringe patterns. The process of external perturbation reconstruction is theoretically studied and numerically calculated, which shows that the reconstructed perturbation matches well with true perturbation. With finite spectral recording, reconstructed perturbation signal shows strong oscillation, which is suppressed effectively by smoothing treatment..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 612002 (2012)
Structured Light Acquisition System Based on Waveband Separation
Liu Di, Yao Zhenning, Li Haifeng, Liu Xiangdong, and Liu Xu
Color-coded structural light system can reconstruct the 3D contour of the object in one shot by the using of three different patterns embedded into three color channels of the projector and camera. However, it cannot reconstruct a color object, and the crosstalks between different channels lower the accuracy. A novel cColor-coded structural light system can reconstruct the 3D contour of the object in one shot by the using of three different patterns embedded into three color channels of the projector and camera. However, it cannot reconstruct a color object, and the crosstalks between different channels lower the accuracy. A novel color-coded structural light system is presented. By using multiple cameras and well designed beam splitter prism and filter, color crosstalk between different color channels in color-coded structural light system is eliminated. A process of two-shot acquiring color object prefile based on three-step phase measurement profilometry is analysed. Color calibration method is discussed to improve the system′s accuracy. After all the procedures, a colorful object can be reconstructed in two shots, which combines the speed and accuracy..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 612003 (2012)
Research on an Optical-Fiber Low-Coherence Interferometric Sensing System Based on Multiplexing Interferometric Technology
Li Zhaoying, Xie Fang, Ma Sen, and Liu Yiqin
An optical-fiber low-coherence interferometric sensing system, which is suitable for distance and absolute measurement, is presented. The system includes two optical fiber inteferometers. One of the optical fiber interferometer is embedded in the measured field for sensing the measurand and absolute measurement can be An optical-fiber low-coherence interferometric sensing system, which is suitable for distance and absolute measurement, is presented. The system includes two optical fiber inteferometers. One of the optical fiber interferometer is embedded in the measured field for sensing the measurand and absolute measurement can be realized. The measurement range is never limited by the optical wavelength. And the other optical fiber interferometer is for demodulating the measurand. Based on wavelength-division-multiplexing technology, the demodulating optical fiber interferometer works in both modes of low-coherence interferometry and high-coherence interferometry. The signal of low-coherence interferometry is for determining the amplitude of the measurand, and the signal of high-coherence interferometry is for measuring the measurand precisely. The measurement range is 6 mm and the resolution is less than 1 nm. The linear correlation coefficient of the displacement measurement is 0.99..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 612004 (2012)
A Novel Adaptive Windowed Fourier Transform for Phase Retrieval in 3D Shape Measurement
Wang Chenxing, and Da Feipeng
Method of adaptive windowed Fourier transform based on Hilbert-Huang transform (HHT) is presented to address the issue of adaptive selection of window size and spectrum aliasing in multiscale windowed Fourier transform for phase retrieval of fringe pattern. Spectrum obtuined by HHT is analyzed to adaptively determine tMethod of adaptive windowed Fourier transform based on Hilbert-Huang transform (HHT) is presented to address the issue of adaptive selection of window size and spectrum aliasing in multiscale windowed Fourier transform for phase retrieval of fringe pattern. Spectrum obtuined by HHT is analyzed to adaptively determine the background and instantaneous frequencies which can describe the change of signals in detail for fringe pattern. By using the presented steps, local stationary regions are located adaptively according to instantaneous frequencies, and then scale factors of window function are got. Before performing adaptive windowed Fourier transform, the background which has been determined is eliminated from fringe pattern to avoid spectrum aliasing caused by expansion of zero-spectrum especially without extra computation. Compared with the method such as the ridge of wavelet transform or the ridge of S transform, the presented method is not limited by hypothesis of linear approximation and changing slowly for measured phase. Experments illustrate the effectiveness and feasibility of this method which is accurate and robust even for measurement of object which carries with steep edge or complex surface..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 612005 (2012)
Integrated Optics
Analysis on Acoustic Surface Wave and Acousto-Optic Interactions in Silica Waveguide Bragg Devices
Chen Chen, Shi Bangren, Guo Lijun, Zhao Meng, and Zhang Rong
The properties of silica waveguide Bragg devices are analyzed. The field distribution of the transverse electric (TE) mode is given for the silica asymmetric slab waveguide. The characteristic equations for SiO2/ZnO/Air multilayered structures are obtained after writing the equations of state, equations of motion and MThe properties of silica waveguide Bragg devices are analyzed. The field distribution of the transverse electric (TE) mode is given for the silica asymmetric slab waveguide. The characteristic equations for SiO2/ZnO/Air multilayered structures are obtained after writing the equations of state, equations of motion and Maxwell′s equations, then the displacement and the electromagnetic field in each region are found with the appropriate boundary conditions. The change of the relative dielectric permeability tensor by the acoustic surface wave is calculated. The relationships among acousto-optic diffraction efficiency, overlap integral between the optical and acoustic fields, acoustic power, acoustic frequency, acoustic aperture and waveguide parameters are discussed. The results show that there is a good overlap of the optical and surface acoustic wave fields in the low surface acoustic wave frequency range; the overlap integral of the lower-order mode is always larger than that of the higher-order; the lowest-order waveguide mode exhibits the strongest acousto-optic interaction and requires the lowest acoustic power; at the same acoustic power, increasing acoustic aperture results in an increase in the diffraction efficiency..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 613001 (2012)
Lasers and Laser Optics
Temperature Field Analysis of Laser Medium with Rough Surface Heat Conduction
Lian Tianhong, Wang Shiyu, Guo Zhen, Li Bingbin, Lin Lin, Cai Defang, and Liang Xingbo
A surface heat source adjustment approach to calculate temperature field is presented in this paper. In the approach, virtual surface heat source is introduced at the boundary of the object to solve the boundary value problem of the steady-state heat conduction equation. A contact model of rough surfaces with heat condA surface heat source adjustment approach to calculate temperature field is presented in this paper. In the approach, virtual surface heat source is introduced at the boundary of the object to solve the boundary value problem of the steady-state heat conduction equation. A contact model of rough surfaces with heat conduction connection is established. On this basis, the randomly distributed boundary conditions are established, and the temperature field in the medium is computed by using the surface heat source adjustment method. The result shows that the temperature field presents some random fluctuation due to the untight contact between the actual surfaces. The fluctuation is very obvious near the boundary while it is not obvious at the center, and the smaller the effectively contacted area, the more obvious the fluctuation is. For example, the fluctuation of 50% effective contact is more obvious than that of 75%..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 614001 (2012)
Numerical Simulation and Experimental Study on Thermal Effects of 2.94 μm Er:YAG Laser
Yang Jingwei, Wang Li, Wu Xianyou, and Jiang Haihe
The theory of thermal-induced-depolarization is analyzed. The distribution of depolarization is numerically simulated, and the result is verified by the experiment of the polarized light polarization interference. The experimental result is consistent with the numerical one, which shows that the distribution of depolarThe theory of thermal-induced-depolarization is analyzed. The distribution of depolarization is numerically simulated, and the result is verified by the experiment of the polarized light polarization interference. The experimental result is consistent with the numerical one, which shows that the distribution of depolarization in the cross section of Er:YAG rod is a crisscross and increases with the pump energy. The direction of the worst depolarization is along 45° angle with the polarization. A simple way is illustrated to measure the thermal lens focal length of the lamp-pumped Er:YAG laser with the critical stability condition of the cavity. The equivalent thermal focal length of Er:YAG crystal under different pump powers is also measured..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 614002 (2012)
Investigation on Eye-Safe Ring-Cavity KTP Optical Parametric Oscillator with Seed Injection
Long Qiqiang, Zhong Kai, and Hong Guanglie
An eye-safe laser source at 1.57 μm is demonstrated by using a non-critically phase-matched (θ=90°, φ=0°) ring cavity optical parametric oscillator pumped by an electro-optic Q-switched Nd:YAG laser. Theoretical and experimental results show that reducing the cavity length and injection of seed laser can effeAn eye-safe laser source at 1.57 μm is demonstrated by using a non-critically phase-matched (θ=90°, φ=0°) ring cavity optical parametric oscillator pumped by an electro-optic Q-switched Nd:YAG laser. Theoretical and experimental results show that reducing the cavity length and injection of seed laser can effectively reduce the threshold, and increase the output energy. When the Nd:YAG laser energy is 88 mJ and the injected signal power changes from 0 to 6 mW, the output energy is enhanced from 8.8 to 14 mJ. When the pump energy is 167.7 mJ and the injected signal power is 6 mW, the maximum output energy of 46 mJ is obtained, corresponding to the peak power of 7.44 MW..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 614003 (2012)
Nonlinear Optics
Influence of Fiber Loss on Optical Parametric Process with Pump Depletion
An Junge, Wu Baojian, Li Zhi, and Ma Huidong
The influences of fiber loss and pump depletion on single-pump four-wave mixing (FWM) parametric process in the isotropic and highly-nonlinear optical fiber are considered. The power conversion relation of the guided optical waves is expressed by an elliptic equation, and the calculated results are consistent with the The influences of fiber loss and pump depletion on single-pump four-wave mixing (FWM) parametric process in the isotropic and highly-nonlinear optical fiber are considered. The power conversion relation of the guided optical waves is expressed by an elliptic equation, and the calculated results are consistent with the simulation datum obtained by OptiSystem software. The elliptic equation is also used to analyze the performance of all optical 2R regenerators based on FWM. The research shows that the increase of fiber loss coefficient can not only deteriorate the re-amplifying performance, but also lead to the decrease and increase of noise tolerances of input high and low levels, respectively..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 619001 (2012)
Research of Self-Similar Region in a Dispersion-Decreasing Fiber
Lü Hua, Zhang Qiaofen, and Wu Xiao
Based on nonlinear Schrodinger (NLS) equation, self-similar region in which pulses can propagate with a parabolic intensity profile in dispersion-decreasing fiber (DDF) is established by split-step Fourier method and waveform analysis, influences of initial pulse and fiber parameters on self-similar region and the speeBased on nonlinear Schrodinger (NLS) equation, self-similar region in which pulses can propagate with a parabolic intensity profile in dispersion-decreasing fiber (DDF) is established by split-step Fourier method and waveform analysis, influences of initial pulse and fiber parameters on self-similar region and the speed of evolution are also investigated. Results show that reduction of initial pulse energy can expand self-similar region but slow down the self-similar evolution. Initial pulse width has an optimum value with the widest self-similar region and relatively high evolution speed. Input pulses with Gaussian profile have a faster evolution speed and a wider self-similar region than those with hyperbolic secant profile. To get an extensive region for self-similar propagation, a DDF with smaller nonlinearity parameter can be used, and the increase of nonlinearity parameter can speed up self-similar evolution. In addition, group-velocity dispersion parameter and gain coefficient should be set at its optimum value to get the largest self-similar region and the fastest evolution speed..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 619002 (2012)
Solutions and Stability of Ultraviolet Localized Optical Vortex Solitons in Air
Xu Yin, and Zhang Hua
From the nonlinear effects of ultraviolet beam in air, the beam propagation equation which includes several nonlinear effects, such as the three-photon ionization of oxygen, is obtained. From this nonlinear Schrdinger equation, the generation of localized optical vortex soliton (LOVS) for ultraviolet light in air is iFrom the nonlinear effects of ultraviolet beam in air, the beam propagation equation which includes several nonlinear effects, such as the three-photon ionization of oxygen, is obtained. From this nonlinear Schrdinger equation, the generation of localized optical vortex soliton (LOVS) for ultraviolet light in air is investigated. The LOVS dynamics is homologous to the movement of particles in a potential well. The initial conditions for the generation of LOVS in air are analyzed. Numerical simulations show the LOVS solutions in polar coordinates, and in the solutions of equation many rings appear with the increase of initial amplitude. Finally, the light-intensity distribution′s variation as propagation constant is confirmed numerically. Numerical simulations also show the relation of beam size, power and initial amplitude. The stability of solution is checked by the stability criterion of Skarka..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 619003 (2012)
Efficient Electro-Optical Controlled Difference-Frequency Conversion in Quasi-Periodic Optical Superlattice
Li Peipei, Tang Haibo, and She Weilong
In order to obtain as high efficiency of difference frequency conversion as possible, a method based on the cascaded electro-optic and difference frequency theory in the quasi-periodically poled LiNbO3 optical superlattice (QPPLN) is put forward. The idea is that an external electric field is applied along the y-axis oIn order to obtain as high efficiency of difference frequency conversion as possible, a method based on the cascaded electro-optic and difference frequency theory in the quasi-periodically poled LiNbO3 optical superlattice (QPPLN) is put forward. The idea is that an external electric field is applied along the y-axis of the QPPLN to control the energy conversion among the pump beam, signal beam, o-polarized difference-frequency beam and e-polarized difference-frequency beams. The numerical results show that, in a 40-mm long QPPLN at 100 ℃, when the ratio r of the intensity of the 1550-nm signal beam to that of the 1064 nm pump one, is less than 0.324, any pump light with an intensity higher than a specific value can be fully translated into the 1550-nm signal light and the 3393.4-nm difference-frequency light as long as a suitable electric field is applied. In the case that r is equal to or larger than 0.324, only in a fixed range can the pump light be translated into signal and difference-frequency ones completely under an appropriate applied electric field. Out of the range the applied electric field cannot increase the efficiency of difference-frequency conversion. The further investigation indicates that the difference-frequency conversion modulated by electro-optical effect is not sensitive to both temperature and domain structure error..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 619004 (2012)
Influences of Optical Breakdown on Wideband SBS and Forward SRS
He Xingdao, Xu Jinjun, Shi Jiulin, Chen Wei, Mo Xiaofeng, and Liu Juan
Wideband stimulated Brillouin scattering (WSBS) and forward stimulated Raman scattering (FSRS) in water pumped by a multi-longitudinal-mode laser are studied. The experimental results indicate that in the pump process of multi-longitudinal-mode laser, energy changes exist between WSBS and FSRS. WSBS will be dominant whWideband stimulated Brillouin scattering (WSBS) and forward stimulated Raman scattering (FSRS) in water pumped by a multi-longitudinal-mode laser are studied. The experimental results indicate that in the pump process of multi-longitudinal-mode laser, energy changes exist between WSBS and FSRS. WSBS will be dominant when the focal length is shorter or the pump energy is lower; on the contrary, FSRS will be dominant with the increase of focal length and pump energy or the appearance of optical breakdown..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 619005 (2012)
Ultraviolet-Light-Induced Absorption and Its Relaxation in Fe-Doped Near-Stoichiometric LiNbO3
Zhang Yanli, Liu Youwen, Yang Yongmei, and He Chongjun
Near-stoichiometric lithium niobate (SLN) crystals doped with low iron are grown, in which the mass fractions of iron are 0×10-6, 5×10-6, 10×10-6, 25×10-6, 50×10-6, 100×10-6, respectively. And their ultraviolet-visible transmission spectra are measured. The concentrations of Fe2+ and Fe3+ Near-stoichiometric lithium niobate (SLN) crystals doped with low iron are grown, in which the mass fractions of iron are 0×10-6, 5×10-6, 10×10-6, 25×10-6, 50×10-6, 100×10-6, respectively. And their ultraviolet-visible transmission spectra are measured. The concentrations of Fe2+ and Fe3+ are estimated by the linear absorption coefficients at the wavelength of 477 nm. The dynamic process and steady characteristics of the light-induced absorption of crystals are investigated by the pump-probe (365 nm and 632.8 nm) method. The results show that the dark decay process of light-induced absorption exhibits a stretched-exponential behavior, and the decay time constant (i.e., the small polaron lifetime) decreases with the Fe-doped concentration and the pump intensity, while the stretching factor decreases with the pumping intensity. The electron transport equations are solved numerically by the four-order Runge-Kutta method, and the whole process of the light-induced absorption in the SLN crystals doped with Fe is simulated, which is consistent with the experimental results..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 619006 (2012)
Optical Design and Fabrication
Design and Optimization of Main Curvature Difference for Progressive Addition Lenses
Wu Quanying, Tang Yunhai, Qian Lin, and Liu Lin
The heights design principle of progressive addition lenses is described. A method is proposed to change the mean curvature to design and optimize progressive addition lenses by adjusting the main curvature difference. The designed and manufactured results of progressive addition lenses are compared, and the powers in The heights design principle of progressive addition lenses is described. A method is proposed to change the mean curvature to design and optimize progressive addition lenses by adjusting the main curvature difference. The designed and manufactured results of progressive addition lenses are compared, and the powers in effective usable portions are maintained before and after optimization. The intermediate widths of the optimized lens are 0.7 mm wider than those of the unoptimized ones. The areas of the effective visual region of the optimized lens are broader than those of the unoptimized lens. The maximum astigmatism reduces slightly. It is shown that the design and optimization method proposed meet the practical demands..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 622001 (2012)
Aspheric Optical Design of an Imaging Spectrometer Based on Acousto-Optic Tunable Filter
Xiong Shengjun, Zhang Ying, Zhao Huijie, Li Xudong, and Zhou Pengwei
Based on the principle of acousto-optic tunable filter (AOTF), the optical system of an imaging spectrometer is designed. The spectral range of the system covers 0. 44～0.78 μm. An even aspheric surface is used to improve the imaging quality, optical transmissivity and simplify the lens structure. A telecentric optical Based on the principle of acousto-optic tunable filter (AOTF), the optical system of an imaging spectrometer is designed. The spectral range of the system covers 0. 44～0.78 μm. An even aspheric surface is used to improve the imaging quality, optical transmissivity and simplify the lens structure. A telecentric optical arrangement is designed using a doublet lens for the fore-optical system. And for the rear imaging lens, a triplet lens is used which contains an aspheric surface. The aspheric surface and its location are optimized based on the primary aberrations theory of aspheric. The system takes the +1 order diffracted beams for imaging. The modulation transfer function (MTF) of the optical system is better than 0.6 at the spatial frequency of 32 lp/mm and the tolerance is moderate..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 622002 (2012)
Optical Devices
Thermal Simulation of Alternating Current Light Emitting Diodes
Deng Hui, Lü Yijun, Gao Yulin, Zhu Lihong, Chen Yingliang, Lin Yue, Guo Ziquan, Wang Kai, Chen Guolong, and Chen Zhong
Alternating current light emitting diodes (AC-LED) have attracted more and more attentions due to the advantage of free of alternate current (AC)/direct current (DC) converter in practical application. With the increase of input power, the rising junction temperature will have negative influence on the the luminous fluAlternating current light emitting diodes (AC-LED) have attracted more and more attentions due to the advantage of free of alternate current (AC)/direct current (DC) converter in practical application. With the increase of input power, the rising junction temperature will have negative influence on the the luminous flux, the optical power, the lifetime and other parameters of LED. Therefore, the understanding of the principle of accurate temperature rise of AC-LED is the key to the chip design. The finite-element analysis software (FloEFD) is used to simulate the transient thermal properties of 1 W white AC-LED driven by DC and AC power respectively. The results show that the junction temperature of AC-LED driven by AC power, fluctuates periodically around that driven by DC power and the fluctuation frequency is the same as that of the input signal, but with an apparent phase shift. Meanwhile, the variation of junction temperature of AC-LED driven at different powers and frequencies shows that the average junction temperature and its fluctuation amplitude increases linearly with the input power at steady state, however, decreases with the increase of frequency..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 623001 (2012)
Precise Analysis of the Intensity Splitting Ratio of Double Wollaston Prism
Zhu Huafeng, Nan Yujie, Yun Maojin, Wang Xiumin, Song Lianke, Wang Ning, and Li Dailin
The exact expression about the intensity splitting ratio of double Wollaston prism is given based on reflection law, multiple-beam interference and Fresnel formula. The effect of the incident angle, the wavelength of incidence and the cut angle on the splitting ratio is given by Matlab software simulation, which resultThe exact expression about the intensity splitting ratio of double Wollaston prism is given based on reflection law, multiple-beam interference and Fresnel formula. The effect of the incident angle, the wavelength of incidence and the cut angle on the splitting ratio is given by Matlab software simulation, which results in the fact that the influence of incident angle, wavelength and cut angle on the intensity splitting ratio is negligible for glue spaced prism, and tremendous for air spaced types. The intensity splitting ratio varies periodically with these parameters for both types prism..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 623002 (2012)
Solar Simulator Irradiation Uniformity Based on Optical Integrator
Gao Yue, Zhang Guoyu, Zheng Ru, Gao Di, and Sun Shi
Optical integrator is a key optical device of the solar simulator for uniform illumination. The composition and working principle of the optical integrator are introduced, and effect of the azimuth offset error and the tilt offset error of on the irradiation uniformity are elaborated. According to the working principleOptical integrator is a key optical device of the solar simulator for uniform illumination. The composition and working principle of the optical integrator are introduced, and effect of the azimuth offset error and the tilt offset error of on the irradiation uniformity are elaborated. According to the working principle of the optical integrator, effect of two axis-consistency errors on the irradiation uniformity are analysed by using the LightTools. Combining with experimental results, effect of tilt offset error relative azimuth error on the irradiation uniformity of system is more serious. Analysis of axis consistency error can provide the necessary reference for tuning mechanism of the optical integrator and the practical alignment..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 623003 (2012)
Study on Resonant Frequency for a Novel MEMS Micro Scanning Mirror
Yan Bin, Yuan Weizheng, Qiao Dayong, Liu Yaobo, Wu Meng, and Li Zhao
Based on the micro-opto-electro-mechanical systems (MOEMS) technology, a new resonant micro scanning mirror using silicion-on-insulator (SOI) process is designed and fabricated. Its basic operational principle and structural characterizations are briefly introduced. The resonant frequency considered to be its most impoBased on the micro-opto-electro-mechanical systems (MOEMS) technology, a new resonant micro scanning mirror using silicion-on-insulator (SOI) process is designed and fabricated. Its basic operational principle and structural characterizations are briefly introduced. The resonant frequency considered to be its most important mechanical parameter is theoretically computed according to the two designed structural dimensions and numerically simulated by combining the finite element simulation tool of ANSYS. A simple but efficient optical system is set up for practically measuring their scanning angle of the designed micro scanning mirror. According to the characteristic of hysteretic frequency responses of parametric excitation of the designed micro scanning mirror, the resonant frequency is measured. To verify the accuracy of the testing results, the resonant frequency is achieved by the laser Doppler vibrometer (LDV). With the driving voltage of 10 V, the mechanical scanning angles for the square and circular scanning mirror reach to about 6° and 5° respectively while the drive frequencies are 556 Hz and 596 Hz. Furthermore, the resonant frequency approximately reaches to 300 Hz and 277 Hz. All the derived results are comparised and very error cause is analyzed..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 623004 (2012)
Pneumatic Force Actuator for Telescope Primary Mirror Support
Tang Jinlong, Zhang Jun, Wang Shaobai, and Xian Hao
In order to obtain fine optical imaging quality, large astronomical telescopes commonly utilize active support system to correct surface deflection of the primary mirror. A device of pneumatic force actuator for telescope primary mirror support is designed and tested. Based on the principle of pneumatic systems, a typeIn order to obtain fine optical imaging quality, large astronomical telescopes commonly utilize active support system to correct surface deflection of the primary mirror. A device of pneumatic force actuator for telescope primary mirror support is designed and tested. Based on the principle of pneumatic systems, a type of pneumatic force actuator with a rolling diaphragm element is designed for primary mirror active support. In the actuator, a force decoupler with ball bearing is adopted to eliminate lateral force and flexural torque. In addition, a proportional-integral-differential (PID) control algorithm with dead zone is designed for the actuator. When the telescope′s elevation angle changes with the speed of 2°/s, the support force output can vary from 0 to 1000 N and the error is only ±0.4% of the full range. The experimental results show that the pneumatic force actuator designed is with good performance in static and dynamic force output..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 623005 (2012)
Study of Photonic Band Gap of 2D Photonic Crystals Used in Short-Wavelength LED
Liu Jinchuan, Jiang Wei, Li Shuping, and Kang Junyong
Using plane wave expansion (PWE) method, four kinds of promising two-dimensional (2D) photonic crystals including square air holes, hexagonal air holes, square rods and hexagonal rods aiming at short-wavelength light emitting diode (LED) are studied. Transverse electric (TE) and transverse magnetic (TM) photonic band gUsing plane wave expansion (PWE) method, four kinds of promising two-dimensional (2D) photonic crystals including square air holes, hexagonal air holes, square rods and hexagonal rods aiming at short-wavelength light emitting diode (LED) are studied. Transverse electric (TE) and transverse magnetic (TM) photonic band gaps (PBGs) are calculated under different lattice constants with different air filling fractions (AFFs) and ratios of pillar radius to lattice constant. The analysis of data indicates that the center wavelength of PBG increases with smaller AFF. Compared with other structures, the structure with square rods has more potential in improving the extraction efficiency of short-wavelength LED, while those with hexagonal rods and hexagonal air holes are suitable for structuring short-wavelength polarization LED..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 623006 (2012)
Physical Optics
Focusing Features of Concentric Three-Ring Non-Uniform Mixing Polarization Vector Beams
Chang Qiang, Yang Yanfang, He Ying, Leng Mei, and Liu Haigang
The focusing property of concentric three-ring non-uniform mixing polarization vector beams through a high numerical aperture is theoretically investigated near the focal plane by using Richards-Wolf vectorial diffraction method. This kind of vector beams can be obtained by letting a concentric three-ring local linearlThe focusing property of concentric three-ring non-uniform mixing polarization vector beams through a high numerical aperture is theoretically investigated near the focal plane by using Richards-Wolf vectorial diffraction method. This kind of vector beams can be obtained by letting a concentric three-ring local linearly polarized cylindrical vector beam passes through a phase retarder with a phase angle δ. The three ring local linearly polarized cylindrical vector beam consists of the outer circle whose polarization is along the radially inward, the inner circle portion whose polarization is along the radially outward and the centray circle whose polarization direction has an angle φ2 with radial direction. The results of the numerical simulation show that the focusing intensity distribution of the non-uniform mixing polarization vector beams is closely related with parameters φ2 and δ. It is shown that the 3D dark optical chain along optical axis can be obtained near the focus by modulating the value of φ2 and δ, which has potential application in the optical micro-manipulation..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 626001 (2012)
Angular Momentum Characteristics of Cylindrical Vector Beams
Yang Shuangyan, Wang Tingting, and Li Chunfang
The representation theory of nonparaxial light beams is introduced. On the basis of this theory, the decomposition of angular momentum of nonparaxial light beams is well solved. The total angular momentum of an arbitrary free electromagnetic field is separated rigorously into spin and orbital parts, both of which are dThe representation theory of nonparaxial light beams is introduced. On the basis of this theory, the decomposition of angular momentum of nonparaxial light beams is well solved. The total angular momentum of an arbitrary free electromagnetic field is separated rigorously into spin and orbital parts, both of which are dependent on the state of polarization and polarization ellipticity. The angular momentum problem of cylindrical vector beams is mainly researched. Based on the expressions of cylindrical vector beams and angular momentum operators given both in momentum space and position space, it is shown that cylindrical vector beams with a helical phase structure are the eigenstates of total angular momentum in the propagation direction, and the eigenvalue of total angular momentum has no relationship with polarization ellipticity. This provides a new calculation of the angular momentum for this special kind of light beams..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 626002 (2012)
Quantum Optics
Transfer of Quantum Information with the System of Atoms Interacting with Coupled Cavities Via Two-Photon Hopping Interaction
Lu Daoming
A scheme is proposed for transferring quantum information with the system of atoms interacting with coupled cavities. The scheme is based on the resonant interaction of two-level atom with cavity field via a two-photon hopping. Through controlling the time of atom interacting with the cavity field, the quantum informatA scheme is proposed for transferring quantum information with the system of atoms interacting with coupled cavities. The scheme is based on the resonant interaction of two-level atom with cavity field via a two-photon hopping. Through controlling the time of atom interacting with the cavity field, the quantum information can be transferred from an atom to another atom or from a cavity to another cavity..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 627001 (2012)
Generation System of Continuous-Variable Six-Partite and Eight-Partite Star Cluster Entangled States
Zhao Yaping, Hao Shuhong, Su Xiaolong, and Xie Changde
Cluster entangled state is the fundamental resource of one-way quantum computation. Star Cluster state can be applied to build quantum network. Based on two-mode squeezing states generated by nondegenerate optical parametric amplifiers an experimental generation scheme of continuous-variable six-partite and eight-partiCluster entangled state is the fundamental resource of one-way quantum computation. Star Cluster state can be applied to build quantum network. Based on two-mode squeezing states generated by nondegenerate optical parametric amplifiers an experimental generation scheme of continuous-variable six-partite and eight-partite star Cluster entangled states is designed, and the corresponding quantum inseparability criteria is deduced. The calculation results show that when the gain factors in inseparability criteria is set to be 1, Cluster entanglement should be prepared with some initial squeezing. But when optimal gain factors are chosen, star Cluster entanglement can be demonstrated with low squeezing. The calculation provides a direct reference for designing experimental system..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 627002 (2012)
Remote Sensing and Sensors
Hollow Optical Fiber Sensor Based on Surface Plasmon Resonance
Zhao Huaxin, Jiang Yongxiang, Luo Tianqiong, Zhu Xiaosong, and Shi Yiwei
A new kind of hollow optical fiber sensor based on surface plasmon resonance (SPR) is designed. The performance of the designed sensor is theoretically analyzed with a ray model theory. The influences of different configurations of the sensor are also analyzed. It is shown that this hollow optical fiber SPR sensor is mA new kind of hollow optical fiber sensor based on surface plasmon resonance (SPR) is designed. The performance of the designed sensor is theoretically analyzed with a ray model theory. The influences of different configurations of the sensor are also analyzed. It is shown that this hollow optical fiber SPR sensor is more flexible in use than conventional fiber SPR sensors because it can change sensing probes to fit sensing medium with different refractive indexes..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 628001 (2012)
Simulation Modeling and Analysis of Full-Waveform Ladar Signatures
Zhao Mingbo, He Jun, and Fu Qiang
Simulation modeling and analysis of full-waveform echo signals is an important research content of full-waveform ladar detection technology. For obtaining projection points of the laser beam in the target scene, a novel ray intersection fast algorithm based on the space boundary of the laser beam is proposed, which hasSimulation modeling and analysis of full-waveform echo signals is an important research content of full-waveform ladar detection technology. For obtaining projection points of the laser beam in the target scene, a novel ray intersection fast algorithm based on the space boundary of the laser beam is proposed, which has high computing efficiency and robustness. Based on the spatial and temporal distribution characteristics of ladar signal, the response function of its projection points in the target scene is calculated, and the interaction between the ladar signal and target scene is also modeled. For full-waveform detection of range-gated mode, classified modeling and analysis of the positional relationship between echo signal and range-gated threshold are implemented. A full-waveform ladar echo signal simulation system is constructed on the basis of the three key technologies. Full-waveform characteristics of the echo signal under different range-gated thresholds are simulated and analyzed, and full-waveform ladar data of the hidden target in a complex scene is also produced..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 628002 (2012)
Scattering
Equivalence of Light Scattering by One Internal-Mixed Model for Aerosol Particles
Zhang Xiaolin, Huang Yinbo, and Rao Ruizhong
For the monodispersion of dust and black carbon particles coated by water in internal mixing state, the validity of equivalent refractive index for the mixture is analyzed using extinction-, absorption-, scattering-efficiency factors and asymmetry parameters. The equivalences for extinction-, absorption- and scatteringFor the monodispersion of dust and black carbon particles coated by water in internal mixing state, the validity of equivalent refractive index for the mixture is analyzed using extinction-, absorption-, scattering-efficiency factors and asymmetry parameters. The equivalences for extinction-, absorption- and scattering-efficiency factors are good with the relative errors less than 3%、 3% and 4%, respectively at different radius ratios for the size parameters from 0.1 to 25. The equivalence for asymmetry parameters is relatively a bit poor with the relative errors less than 13%. The complex refractive indices can almost be determined for the radius ratio less than 1/5, which is irrespective of the size parameter. It is easy to obtain the equivalent refractive indices of the internal mixture of particles using the optical parameters except the scattering phase function..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 629001 (2012)
Angular Dependence of Dynamic Light Scattering
Liu Xiaoyan, Shen Jin, Zhu Xinjun, Sun Xianming, and Liu Wei
Multiangle dynamic light scattering (MDLS) technique can give better particle-size distribution (PSD) than single-angle dynamic light scattering (SDLS) technique. However, the choice of scattering angles is affected by the measuring particles in MDLS. Unimodal simulation distribution of 100 nm and 500 nm and bimodal siMultiangle dynamic light scattering (MDLS) technique can give better particle-size distribution (PSD) than single-angle dynamic light scattering (SDLS) technique. However, the choice of scattering angles is affected by the measuring particles in MDLS. Unimodal simulation distribution of 100 nm and 500 nm and bimodal simulation distribution of 300 nm and 600 nm are respectively measured at one, three, six and nine scattering angles and are inversed to obtain the PSD. This results show that MDLS can give better PSD with the increase of number of angles. Furthermore, the PSD has a little modification when there are more than one angle for 100 nm particles or more than three angles for 600 nm particles. A dilute bimodal suspension of polystyrene latex standard spheres mixed in a number ratio of 51 is measured at one, three, five and ten angles. The results show that one angle only can give one peak and more than three angles can give two peaks. The number ratio is closer to the true value with the increase of number of angles. Though MDLS can give better PSD than SDLS, the improvement of PSD become less obvious with the increase of number of angles. In some cases, the PSD may become worse with the increase of angle numbers because the calibration noise of scattering angle and measurement noise of light-intensity correlation function are added..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 629002 (2012)
Analysis of Composite Light Scattering Properties Between Wafers and Many Shapes of Particles with Different Positions
Gong Lei, Wu Zhensen, and Gao Ming
Combing the practical situation of nondestructive examination, the analysis of composite light scattering properties between wafers and many shapes of particles with different positions is shown. Against the half-space problem about wafer and defect particles, the generalized perfectly matched layer (GPML) can work verCombing the practical situation of nondestructive examination, the analysis of composite light scattering properties between wafers and many shapes of particles with different positions is shown. Against the half-space problem about wafer and defect particles, the generalized perfectly matched layer (GPML) can work very well. The boundary consistency conditions are given by three waves method. The reciprocity theorem is applied to near-far field extrapolation. The angle distribution of sphere or ellipsoidal defect particles are given. The results show that the influence of inlaid particles on size is more obvious than inside ones. In the large scattering angle, the contribution of the position factor is much more. In the angle of -10°, 30°, 70°, the differential scattering cross section (DSCS) difference about sphere and ellipsoidal particles is more obvious. In the wafer′s nondestructive examination project, the defect position and shape are diagnosed by the scattering field of specific angles..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 629003 (2012)
Thin Films
Technique to Minimize the Characterization Deviations of Optical Parameters of Thin Films Caused by Ellipsometric Measurement Systematic Errors
Wu Suyong, Long Xingwu, and Yang Kaiyong
A novel errors treatment technique to optical-parameters characterization of thin films is presented based on the effect analysis of systematic errors which are hard to eliminate in ellipsometric measurement data. In order to minimize the characterization deviations of thin film optical parameters from the real values A novel errors treatment technique to optical-parameters characterization of thin films is presented based on the effect analysis of systematic errors which are hard to eliminate in ellipsometric measurement data. In order to minimize the characterization deviations of thin film optical parameters from the real values caused by ellipsometric measurement systematic errors, it is advised to select ellipsometric measurement data used in optical characterization from spectral bands characterized with opposite signs or single zero of first-order ellipsometric angles′ partial derivatives with respect to layer thickness and refractive index for most measurement incident angles, and to exclude spectral bands characterized with the same signs or both zeros of ellipsometric angles′ first-order partial derivatives for all measurement incident angles. The essence of this technique is to minimize the errors transfer effect of measurement data on thin-film optical-parameters characterization through spectral band selection of ellipsometric measurement by first-order partial derivatives analysis. Through numerical simulations, its applicability and selection skills of the range of measurement incident angles are compared and studied. The reliability of this technique is supported by resumable numerical experimental results and reasonable theoretical explanations. This novel errors-treatment technique provides a certain reference to in-situ characterization and thickness monitoring of thin films..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 631001 (2012)
Analysis of Optical Performance on Polymer Solar Cell Based on Transfer Matrix Method
Li Xiang, Wen Shangsheng, Yao Rihui, Chen Dongcheng, and Gui Yuchang
Optical simulations based on transfer matrix method, combined with Matlab have been performed to investigate optical properties of inverted polymer solar cell (IPSC). Effects of thickness, angle of incidence and structure on optical performance of IPSC are studied theoretically. Simulations reveal that optical absorptiOptical simulations based on transfer matrix method, combined with Matlab have been performed to investigate optical properties of inverted polymer solar cell (IPSC). Effects of thickness, angle of incidence and structure on optical performance of IPSC are studied theoretically. Simulations reveal that optical absorption is mainly dependent on active thickness and has faint decrease as thickness of electron transport layer and hole transport layer increase, respectively. Path length of light inside a solar cell increases so that more light is absorbed. The absorption rate reachs its maximum under the angle of 40°. However, as with other optical effects the absorption rate reduced with the increase of angle, when the angles above 40°; Furthermore, simulations demonstrate optical electric field for p-polarized light is discontinuous at boundaries. A microcavity device which has been constructed by a dioxide (TiO2) layer into the basic structure can significantly enhance light absorption due to the optical resonance effect..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 631002 (2012)
Properties of Fluorescence Spectra and Amplified Spontaneous Emission of the Dye-Doped Film Based on Quasi-Waveguide Structure
Lin Hao, Zhou Jun, Yan Cheng′en, and Zhang Lingfen
The characteristics of the fluorescence spectra and amplified spontaneous emission (ASE) spectra of the RhB/PMMA and the Rh6G/PMMA films in the quasi-waveguides structure are experimentally measured and theoretically analyzed. By using of the radiation of the continue-wave laser and pulse laser, the fluorescence and ASThe characteristics of the fluorescence spectra and amplified spontaneous emission (ASE) spectra of the RhB/PMMA and the Rh6G/PMMA films in the quasi-waveguides structure are experimentally measured and theoretically analyzed. By using of the radiation of the continue-wave laser and pulse laser, the fluorescence and ASE of the RhB/PMMA and the Rh6G/PMMA films are realized. It is found that the peaks of the fluorescence and ASE are shifted to longer wavelengths as the increase of the dye-doped concentrations and the film thicknesses. By analogy to the model of laser resonance cavity, the self-absorption effect of doped dyes and the gain amplifications of low-order guided modes transmitted in the dyes-doped films are explained for the quasi-waveguides structures and the relation of the wavelengths of fluorescence peak and ASE peak with the dye-doped concentration are obtained. The results show that the theoretical calculations are consistent with the experimental measurement. It is confirmed that the peak-shifts in the fluorescence spectra and ASE spectra are mainly attributed to the self-absorption effect of dye so that the wavelength of ASE peak can be tuned in wider range by the change of doped dye concentration..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 631003 (2012)
Study on Super-Resolution Readout Performance of Si-Doped Ag Film
Zhao Shilei, Geng Yongyou, and Shi Hongren
Super-resolution film is one functional film which can overcome the optical diffraction limit, which plays an important role in super-resolution near-field technique. Si-doped Ag film is prepared by co-sputtering method and used as a mask which is measured for super-resolution read-only disk. The largest read out signaSuper-resolution film is one functional film which can overcome the optical diffraction limit, which plays an important role in super-resolution near-field technique. Si-doped Ag film is prepared by co-sputtering method and used as a mask which is measured for super-resolution read-only disk. The largest read out signal′s carrier-to-noise ratio (CNR) of the super-resolution read-only disk is 28 dB under the Ag sputtering power of 55 W, the Si sputtering power of 95 W, the sputtering time of 80 s and the film thickness of 39 nm. Film component is analyzed by X-ray photoelectron spectroscopy (XPS). Film microstructure is demonstrated by scanning electron microscope (SEM). Optical constants and thickness of the film are measured by ellipsometer. The readout mechanism of super-resolution film can be explained with the Ag scattering model. The CNR of the super-resolution disk doesn′t decrease more or less after one hundred thousand times readout..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 631004 (2012)
Influence of Annealing Temperatures on Optical Properties of HfSixOy Thin Films Prepared by Magnetron Sputtering
Tian Hao, Liu Zhengtang, Feng Liping, Gao Qianqian, and Liu Wenting
HfSixOy thin films are prepared by using radio-frequency (RF) magnetron sputtering on p-type Si(100) and then annealed in N2 atmosphere. Composition and structure of the films are determined by means of XPS and XRD, respectively. The optical properties in relation to postdeposition annealing temperatures are investigatHfSixOy thin films are prepared by using radio-frequency (RF) magnetron sputtering on p-type Si(100) and then annealed in N2 atmosphere. Composition and structure of the films are determined by means of XPS and XRD, respectively. The optical properties in relation to postdeposition annealing temperatures are investigated by spectroscopic ellipsometry(SE). The XRD analysis shows that the films are amorphous even after annealed at 700 ℃ but crystallization after annealed at 900 ℃. Based on a parameterized Tauc-Lorentz dispersion model, the optical constants of the as-deposited and annealed films related to the annealing temperature are systematically extracted. With the increase of the annealing temperature, the refractive index n of the HfSixOy films increases whereas the extinction coefficient k of the HfSixOy films decreases. The extracted direct band gaps are 5.62, 5.65, 5.68 and 5.98 eV for the as-deposited films and the films annealed at 500 ℃, 700 ℃ and 900 ℃, respectively..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 631005 (2012)
Phase Change Properties of AgInSbTe Thin Films under Single Nanosecond Laser Pulse Irradiation
Zhai Fengxiao, Liang Guangfei, Wang Yang, and Wu Yiqun
Ag8In14Sb55Te23 (AIST) films are deposited on K9 glass substrates by DC magnetron sputtering. A pump-probe system is employed to observe reflectivity change process in real time. The results show that phase transition driven by nanosecond laser pulses can be achieved in a proper fluence range on AIST thin films. The prAg8In14Sb55Te23 (AIST) films are deposited on K9 glass substrates by DC magnetron sputtering. A pump-probe system is employed to observe reflectivity change process in real time. The results show that phase transition driven by nanosecond laser pulses can be achieved in a proper fluence range on AIST thin films. The presence of liquid phase is identified by transient reflectivity level between those of the amorphous and crystalline phases. Crystallization time and reflectivity change are linearly proportional to the energy at lower pulse fluences..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 631006 (2012)
Vision, Color, and Visual Optics
Colorant Selection Based on Gamut Analysis and Cluster Analysis
Li Jincheng, Liu Zhen, Chen Guangxue, Yang Shengwei, and Yu Jieyue
A method of basis colorant selection based on gamut analysis and cluster analysis is proposed. Conventional 4-color gamut and target hifi-color gamut are analyzed to pick out the featured color sets where the colorants exist, and the principal component analysis is performed for the spectral reflectance of these colorsA method of basis colorant selection based on gamut analysis and cluster analysis is proposed. Conventional 4-color gamut and target hifi-color gamut are analyzed to pick out the featured color sets where the colorants exist, and the principal component analysis is performed for the spectral reflectance of these colors to get the numbers of basis colorant m. With the cluster number m, spectral reflectance of the featured colors in the set is divided by clustering method, and the average spectral reflectance of the featured colors is calculated. m spectral reflectance among the m cluster which are most nearest to the average spectral reflectance is selected as the spectral reflectance of the basis colorant. The results show that the proposed method can estimate spectral reflectance of new basis colorant accurately, which realises the maximun reproduction of the target high fidelity color gamut..
Acta Optica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 32, Issue 6, 633001 (2012)
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