Contents
2008
Volume: 28 Issue 9
37 Article(s)
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Research Article
Polarization Beam Splitters Based on One-Dimensional Metal-Dielectric Structure
Zhang Jinlong, Liu Xu, Li Yiyu, and Gu Peifu
A one-dimensional metal-dielectric structure was designed for the application of polarized beam splitter (PBS). The band structure of the one-dimensional metal-dielectric structure is calculated, and the PBS is based on the negative refraction for TM polarization and positive refraction for TE polarization in a given fA one-dimensional metal-dielectric structure was designed for the application of polarized beam splitter (PBS). The band structure of the one-dimensional metal-dielectric structure is calculated, and the PBS is based on the negative refraction for TM polarization and positive refraction for TE polarization in a given frequency range. The transfer matrix method is used to simulate the polarized beam splitting effect as the Gaussian beam enters the finite one-dimensional metal-dielectric structure for both polarizations. The influences of different incident angles and the dissipation of the metal layer absorption on beam splitting are discussed. The simulation shows that this structure possesses the best performance with an incident angle around 55°. For the reason of absorption, the beam splitting ability is limited, the transmittance of TM component changes substantially, but that of TE component is favorable. The transmittance will dicrease and the beam splitting ability will rise when the period of the structure increases. As the operation wavelength increases, the influence of the dissipation of the metal layer will be smaller. This structure can achieve polarized beam splitting in a wide range of wavelength and incident angle with a high transmittance..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1788 (2008)
Study on Application of One-Dimensional Photonic Crystal Microcavity to Luminescence of Silicon-Based Material
Chen Libai, Guo Zhenning, and Lin Jieben
High-efficiency luminescence of Si-based material is essential for the development of photoelectronic integration .One dimensional photonic crystal (1D PC) with microcavity (MC) could enhance its intensity and narrow its spectrum greatly. Several Si-based luminescent 1D PC MC structures are introduced,including single-High-efficiency luminescence of Si-based material is essential for the development of photoelectronic integration .One dimensional photonic crystal (1D PC) with microcavity (MC) could enhance its intensity and narrow its spectrum greatly. Several Si-based luminescent 1D PC MC structures are introduced,including single-mode symmetrical and asymmetrical structures、multi-mode structure and electrically injected structure. Then their transmission spectra of defect modes are calculated by the transfer matrix method,which can reflect their luminescent spectra indirectly..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1793 (2008)
Atmospheric Optics and Oceanic Optics
Close-Loop Experiment of Adaptive Optics System Based on Linear Phase Retrieval Technique
Chen Bo, Li Min, Li Xinyang, and Jiang Wenhan
The experimental research on an adaptive optics (AO) close-loop system based on the linear phase retrieval (LPR) technique is proposed. The experimental system is set up with a CCD camera imaging system, a deformable mirror, and a computer with image collection card and D/A card. In the Windows system, VC program is usThe experimental research on an adaptive optics (AO) close-loop system based on the linear phase retrieval (LPR) technique is proposed. The experimental system is set up with a CCD camera imaging system, a deformable mirror, and a computer with image collection card and D/A card. In the Windows system, VC program is used in the algorithm of image processing and controlling. The wavefront information measured by a high precision Hartmann-Shack (HS) wavefront sensor is used to estimate the correction performance of the AO system. The correction ability, convergence rate and stability of the above system are discussed under different distorted wavefront. The experimental results show that the proposed system can correct the small distorted static wavefront aberration successfully..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1633 (2008)
Finite Element Analysis and Measurement of a 20-Element Bimorph Deformable Mirror
Ning Yu, Zhou Hong, Guan Chunlin, Rao Changhui, and Jiang Wenhan
Influence function is a key parameter to evaluate the capability of bimorph deformable mirrors in correcting aberrations. Influence functions of a 20-element bimorph deformable mirror are measured by Veeco interferometer and simulated by a finite element model. Compared with the measured data, simulated results come ouInfluence function is a key parameter to evaluate the capability of bimorph deformable mirrors in correcting aberrations. Influence functions of a 20-element bimorph deformable mirror are measured by Veeco interferometer and simulated by a finite element model. Compared with the measured data, simulated results come out a little smaller. But they are consistent in both shape and the location of peak. And the finite element model can predict the correction on 1～35 Zernike aberrations of the 20-element bimorph deformable mirror correctly, with errors smaller than 0.1. It is feasible to improve the bimorph deformable mirror by optimization of its finite element model..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1638 (2008)
Effect of Spectral Resolution on Measurement of Trace Gases in Atmosphere by Differential Optical Absorption Spectroscopy
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In the differential optical absorption spectroscopy (DOAS) measurement, the accuracy of the pollutant concentration is determined by the selected spectral resolution. The effect of spectra resolution on the detected characteristic absorption structure of gaseous pollutants and the variation of differential cross sectioIn the differential optical absorption spectroscopy (DOAS) measurement, the accuracy of the pollutant concentration is determined by the selected spectral resolution. The effect of spectra resolution on the detected characteristic absorption structure of gaseous pollutants and the variation of differential cross section of gaseous pollutants with the change of resolution are studied. The effect of spectra resolution on the detection limits of gaseous pollutants is deduced, and the functional dependence of the signal-to-noise ratio (S/N) on the spectral resolution is reduced by studying the relationship between light intensity and spectral resolution, from which the resolution is determined for all the gaseous pollutants with the optimal S/N. The measurement error in detecting the standard gases at different spectral resolution is calculated. The optimized resolution range are determined for the gaseous pollutants, which can yield high sensitivity, good selectivity and reasonable time resolution for the accurate qualitative and quantitative analysis of NO2, O3 and SO2. The real time monitoring of NO2, O3 and SO2 are carried out in the Fengtai district of Beijing, and the measurement result is in good agreement with the result of point instruments..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1643 (2008)
Effect of M2 Factor of Laser Beam for a Non-Coaxial Lidar System
Gao Fei, Hua Dengxin, Wu Min, Mao Jiandong, and Zhou Yi
The propagation properties of Gaussian beam are directly influenced by beam quality factor M2 and the field of view of the receiver of lidar is limited mainly by the fiber core. The geometrical form factor which influences the measurement performance of the lidar system is related strictly with the transmission propertThe propagation properties of Gaussian beam are directly influenced by beam quality factor M2 and the field of view of the receiver of lidar is limited mainly by the fiber core. The geometrical form factor which influences the measurement performance of the lidar system is related strictly with the transmission properties of laser beam and the configuration of the receiving system combined with the coupling fiber and the receiving telescope. This paper discusses mainly the properties of the geometrical form factor due to the beam quality factor M2 and the coupling fiber core, in order to optimize the design of the transmitter and receiver of the lidar and to improve the detection capability of the lidar. The numerical calculation shows that the coupling efficiency of the fiber is largely related with location position of fiber from the focus of the telescope and its core; and the range in which the geometrical form factor is less than one is largely influenced by M2 factor and is increased with the enhance of the value of the M2. The preliminary experiment is used to support the analysis of the influence factors on the performance for a non-coaxial lidar system..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1649 (2008)
Study on Relationship between Extinction Coefficient and Mass Concentration
Li Xuebin, Xu Qingshan, Wei Heli, and Hu Huanling
Retrieving the vertical distribution of aerosol mass concentration by detecting the vertical distribution of extinction coefficient with lidar is important in environment monitoring. It is indispensable to establish the relationship between extinction coefficient and mass concentration. The relation of mass extinction Retrieving the vertical distribution of aerosol mass concentration by detecting the vertical distribution of extinction coefficient with lidar is important in environment monitoring. It is indispensable to establish the relationship between extinction coefficient and mass concentration. The relation of mass extinction coefficient, extinction coefficient and mass concentration is analyzed based on the Mie scattering theory, an equivalent parameter is introduced and the effect of Junge index on the equivalent parameter is discussed. The relationship between aerosd extinction coefficient and mass concentration is validated by measured particles spectrum distribution, visibility, relative humidity and aerosol mass concentration in Beijing,which is significantive for retrieving aerosol mass concentration with lidar..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1655 (2008)
Simultaneous Measurements on Scintillation and Phase Fluctuation of Light Propagation through Atmospheric Turbulence by Shack-Hartmann Wavefront Sensor
Yuan Ke'e, Zhu Wenyue, and Rao Ruizhong
Shack-Hartmann wavefront sensor is used to explore irradiance scintillation effect of light propagation through atmospheric turbulence, whose subaperture and corresponding CCD element are regarded as intensity detector system. Its principle is analyzed. Experiments on phase fluctuation and scintillation are preliminariShack-Hartmann wavefront sensor is used to explore irradiance scintillation effect of light propagation through atmospheric turbulence, whose subaperture and corresponding CCD element are regarded as intensity detector system. Its principle is analyzed. Experiments on phase fluctuation and scintillation are preliminarily carried out in atmospheric boundary layer over 1000 m horizontal path. Compared with the measurement results of traditional large-aperture scintillometer, it is found that the method of Shack-Hartmann wavefront sensor is reliable with correlation coefficient of 0.838. At the same time, the daily variation trend of the refractive index structure constants retrieved from the two atmospheric turbulence effects is compared. The correlation coefficient of the two C2n reaches 0.798 in the log-log grid. All the experimental results indicate that simultaneous measurement of phase fluctuation and scintillation by Shack-Hartmann wavefront sensor is feasible, which extends the function of this sensor..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1659 (2008)
Fiber Optics and Optical Communications
Monodromy Control of Fiber Fabry-Pérot Cavity by Desensibilization for Demodulation of Vibration Frequency
Wang Yanhua, Tan Zhongwei, Ren Wenhua, Liu Yan, and Jian Shuisheng
Vibration signal frequency is measured by monitoring the single wavelength power of fiber Fabry-Pérot (F-P) cavity and applying fast Fourier transform (FFT) to the time domain signal. An instantaneous model is established and the minute response delay between transmission and reflection is shown. It is proved thatVibration signal frequency is measured by monitoring the single wavelength power of fiber Fabry-Pérot (F-P) cavity and applying fast Fourier transform (FFT) to the time domain signal. An instantaneous model is established and the minute response delay between transmission and reflection is shown. It is proved that the multi-reflection of F-P cavity has little influence on the measurement of vibration with a frequency generally not higher than some dozen kilohertz. The waveform will be distorted when the vibration directly applied on the F-P cavity is intense and out of the demodulation monotropic range. Desensiblization is implemented by increasing the distance between the vibration source and the F-P cavity to control the monodromy of demodulation and more accurate demodulation results are obtained when the distance is increased to 8 cm..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1664 (2008)
Study on Self-Induced Chirping for Fiber Bragg Grating
Liu Changjun, Zhang Weigang, Jiang Meng, Tu Qinchang, and Zhao Tianming
Based on coupled mode theory, the reflection properties of the fibre Bragg grating fabricated with phase mask are analysed by transfer matrix method. A new beam path is designed to fabricate fiber gratings and a new short-wavelength self-induced chirping apordized grating with length of 0.015 m is fabricated by GaussiaBased on coupled mode theory, the reflection properties of the fibre Bragg grating fabricated with phase mask are analysed by transfer matrix method. A new beam path is designed to fabricate fiber gratings and a new short-wavelength self-induced chirping apordized grating with length of 0.015 m is fabricated by Gaussian ultraviolet (UV) beam. Furthermore, a new long-wavelength self-induced chirping grating is obtained by cutting the original fiber grating shorter to 0.007 m and 0.0055 m separately. By contrast with the original grating, the new one has more side lobes on the long-wavelength side of the reflection spectrum and the side-lobes on the short-wavelength side are suppressed. On the basis of analysis of the new self-induced chirping grating, a new type of Gaussian-like apodization function is presented and used to simulate the self-induced chirping of the fiber grating. The theoretical results accord with the experimental results..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1671 (2008)
Design and Application of Optical Filters Based on Chirped Phase-Shifted Fiber Gratings
Lu Shaohua, Xu Ou, Feng Suchun, Dong Xiaowei, and Jian Shuisheng
As a transmission type filter, phase-shifted fiber grating has the advantage of low cost and low additional loss, and it is a critical component in optical communication and sensor systems. As for chirped phase-shifted fiber gratings, the transmission peak wavelength and number are determined by the position and numberAs a transmission type filter, phase-shifted fiber grating has the advantage of low cost and low additional loss, and it is a critical component in optical communication and sensor systems. As for chirped phase-shifted fiber gratings, the transmission peak wavelength and number are determined by the position and number of phase shift and the characteristics of the transmission peak are significantly affected by the amount of phase shift. Sectional apodization is used on chirped phase-shifted grating to obtain appropriate filtering properties for optical communication. The transmission peak characteristics are theoretically analyzed by transfer matrix method for chirped phase-shifted gratings with and without apodization. The numerical results show that the amplitude and phase response of the filter are improved and design requirements can be satisfied by proper apodization function and ratio. Meanwhile, the dependence of the transmission peak wavelength and depth on phase shift is diminished greatly and the impact of phase shift can be ignored by proper apodization. A method is proposed to generate millimeter subcarrier optical signal by using a double-channel chirped phase-shifted grating filter..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1675 (2008)
Bending Sensing Rules for Long-Period Fiber Gratings
Zhao Hongxia, Bao Jilong, and Chen Ying
A cetain value, a method to analyze bending sensing rules of long-period fiber grating (LPFG) according to bending curvature, grating length and grating period was reported, based on coupled-mode theory and perturbation approximation. When the bending curvature reaches a cetain value, the transmission spectra of the beA cetain value, a method to analyze bending sensing rules of long-period fiber grating (LPFG) according to bending curvature, grating length and grating period was reported, based on coupled-mode theory and perturbation approximation. When the bending curvature reaches a cetain value, the transmission spectra of the bended LPFG split. The two resonant wavelengths of the splitting peaks change conically with the bending curvature and inversely with grating period, but are indepentent on grating length. The LPFG written on the B-Ge co-doping single-mode fiber proves the above conclusion..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1681 (2008)
Image Processing
Multiframe Blind Deconvolution Restoration of Atmospheric Turbulence-Degraded Images Based on Noise Characteristic
Huang Jianming, and Shen Maozuo
Due to influence of atmospheric turbulence and noise contaminated, the object images are always blurred. To observe object in high resolution, combining characteristic of noise, with physical constraint, a novel method of atmospheric turbulence-degraded images blind deconvolution restoration minimization model is propoDue to influence of atmospheric turbulence and noise contaminated, the object images are always blurred. To observe object in high resolution, combining characteristic of noise, with physical constraint, a novel method of atmospheric turbulence-degraded images blind deconvolution restoration minimization model is proposed. Alternating minimization algorithm based on conjugate gradient method is applied for image restoration. Blurred images by atmospheric turbulence with atmospheric coherent length of 0.1 m for 2 m-diameter telescope and noise with signal-to-noise ratio of 10 dB are restored by the proposed method. The result demonstrates that the drawback of the traditional blind convolution method has been overcome, the influence of atmospheric turbulence and noise has been eliminated and clear observation object images have been restored. The study of blind deconvolution restoration technology purposed is meaningful for ground-based telescope in astronomical observation..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1686 (2008)
Color Image Blind Watermark Algorithm Based on Double Chaotic Scrambling and Spread Spectrum Modulation
Hu Yufeng, and Zhu Shan'an
A new blind watermark algorithm for color image was proposed. First, the green component of the original image was blocked by size 8×8 pixels and transformed with discrete cosine transformation (DCT). Second, two chaotic sequences were generated by logistic mapping, and the binary watermark image was scrambled by A new blind watermark algorithm for color image was proposed. First, the green component of the original image was blocked by size 8×8 pixels and transformed with discrete cosine transformation (DCT). Second, two chaotic sequences were generated by logistic mapping, and the binary watermark image was scrambled by the chaotic sequences and spread spectrum modulated by two uncorrelated random sequences. Third, the modulated watermark was embedded in mid-frequency region coefficients of DCT domain. At last, the watermarked image was obtained by inverse discrete cosine transform. The watermark was extracted by comparing the correlation between two random sequences with watermarked image, the process did not need the original image, namely a blind watermark algorithm. Experimental results demonstrated that this method is invisible and robust against some usual attacks such as JPEG compression, cropping, adding noise, and embedding watermark in green component is more robust against lossy compression than embedding watermark in red or blue component..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1691 (2008)
Nonuniformity Correction Algorithm of Infrared Focal Plane Arrays Based on Steady-State Kalman Filtering
Liu Yongjin, Zhu Hong, and Zhao Yigong
The traditional Kalman-filtering algorithm uses batch processing to realize nonuniformity correction, and causes high computational complexity and memory requirement, and it is more important is that it cannot realize real-time processing. For this reason, a novel nonuniformity correction algorithm based on steady-statThe traditional Kalman-filtering algorithm uses batch processing to realize nonuniformity correction, and causes high computational complexity and memory requirement, and it is more important is that it cannot realize real-time processing. For this reason, a novel nonuniformity correction algorithm based on steady-state Kalman filtering is developed, which can compute the gain matrix of the filter off line according to characteristics of fixed-pattern noise and correct images by using a frame-by-frame iteration. Therefore, this algorithm has lower computational complexity and memory requirements. The fundamental of the proposed technique is described in detail and the performance is demonstrated with both simulated and real infrared imagery. Experimental results indicate that the CPU time and memory requirements that the proposed algorithm needs to correct a frame of image are 1.7188 s and 131.25 KB respectively, which are very suitable for real-time processing..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1697 (2008)
Blind Restoration for Defocus Blurred Image Based on Autocorrelation of Derivative Image
Zhao Lin, Jin Weiqi, Chen Yinan, and Su Binghua
The research on the blind restoration for the images blurred by defocus effect has important meaning and actual metric. A super-resolution blind restoration algorithm for defocus blurred images was suggested according to the model of optical defocusing by using autocorrelation of derivative image. The autocorrelation oThe research on the blind restoration for the images blurred by defocus effect has important meaning and actual metric. A super-resolution blind restoration algorithm for defocus blurred images was suggested according to the model of optical defocusing by using autocorrelation of derivative image. The autocorrelation of the second-order derivative blurred image received by Laplacian was computed, the radius of defocusing blur was be confirmed via the information contained in the result of the autocorrelation, and the restoration was finally achieved by MPMAP super-resolution method using the estimated defocusing radius as parameter. Experiments illuminate that the proposed algorithm can accurately estimate the radius of defocusing blur and restore clear images. Compared with other methods, the proposed algorithm declines the computation quantity, improves result precision and obtaines more detailed information by using the super-resolution restoration algorithm. It has been successfully applied into judging or appraisal of defocus images in practice works..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1703 (2008)
Instrumentation, Measurement and Metrology
Modulation Transfer Function Measurement of Electron Multiplying CCD
Feng Zhiwei, Cheng Haobo, Song Qian, and Shang Yuanyuan
Based on the Fourier power spectrum theory, a measurement method by means of a random white-noise pattern transparent target was presented to analyze the effect of electron multiplication (EM)on the modulation transfer function (MTF) of electron multiplying charge-coupled device (EMCCD). By building an integrated systeBased on the Fourier power spectrum theory, a measurement method by means of a random white-noise pattern transparent target was presented to analyze the effect of electron multiplication (EM)on the modulation transfer function (MTF) of electron multiplying charge-coupled device (EMCCD). By building an integrated system model of EMCCD, the multiplication MTFs at different multiplication gain were measured and discussed in experiments. The experimental results show that the electron multiplication process significantly influences the system MTF, compared with non-EM, especially at high EM gain. MTF declines by an average of about 30% at Nyquist frequency. The MTF and noise of auxiliary imaging optical system and the method of focusing judgment in experiment were also discussed..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1710 (2008)
Measurement for Magnetic Field with Fiber Grating
Peng Hui, Su Yang, Li Yuquan, Cheng Peng, Wu Weilei, and Zhu Yingxun
A new magnetic field measurement method based on Faraday effect and measurement of polarization-dependent loss (PDL) in fiber grating was proposed and analyzed in theory and experiment. When the external magnetic field is applied, the transmission constants of the two circularly polarized lights in fiber grating will bA new magnetic field measurement method based on Faraday effect and measurement of polarization-dependent loss (PDL) in fiber grating was proposed and analyzed in theory and experiment. When the external magnetic field is applied, the transmission constants of the two circularly polarized lights in fiber grating will be changed by the Faraday effect, and so does the PDL of fiber grating. The simulations show there is a linear relationship between the peak value of PDL and magnetic field in a certain range. Moreover, this method is insensitive to temperature. The influence of parameters of grating on measurement performance was analyzed. The measurement sensitivity is 7.8e-6 dB/Gs and the precision is 2 Gs using the optical vector analyzer with 10-5 dB precision in experiment, which agree well with the theoretical analysis..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1717 (2008)
Three-Dimensional Displacement Measurement Based on Single CCD Camera
Sun Wei, He Xiaoyuan, and Zheng Xiang
Owing to the necessity and importance of the technique of three-dimensional (3D) displacement measurement in the filed of engineering, a 3D displacement measurement system based on single CCD camera and digital image correlation is developed. With regard to the relationship between the center and the slope of the displOwing to the necessity and importance of the technique of three-dimensional (3D) displacement measurement in the filed of engineering, a 3D displacement measurement system based on single CCD camera and digital image correlation is developed. With regard to the relationship between the center and the slope of the displacement vector and displacements in- and out-of the object plane, two dimensional Savitzky-Golay (SG) digital differentiator (an operator based on local subset coordinates) is employed to calculate constant terms (corresponding to the in-plane components) and the first order terms (corresponding to the out-of-plane components).On the theoretical basis of the pin-hole camera imaging model, a numerical simulation and an experiment on a non-uniformly deformed cantilever beam are conducted. In addition, the simulated speckle images associated with the 3D deformation are generated, which is further employed to validate the effectiveness and precision of the Newton-Raphson iterative method with a shape function of the second order. Simulated and experimental results demonstrate that both in-plane and out-of-plane displacements can be accurately retrieved using the proposed method..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1723 (2008)
Integrated Optics
Research of Linewidth Stabilizing Method During Defocusing Laser Direct Writing
Jin Zhanlei, Tan Jiubin, Zhang Shan, and Wang Lei
A linewidth stabilizing method for defocusing laser direct writing is proposed for further improvement of line quality of diffractive optical elements. The writing power and defocusing amount are synchronously adjusted to set photoresist threshold at the position where the linewidth variation rate is small, thereby theA linewidth stabilizing method for defocusing laser direct writing is proposed for further improvement of line quality of diffractive optical elements. The writing power and defocusing amount are synchronously adjusted to set photoresist threshold at the position where the linewidth variation rate is small, thereby the linewidth sensitivity to variation of actual exposure dose and photoresist threshold is weakened, and then the linewidth stability during defocusing laser direct writing is guaranteed. Both the power control model and linewidth model of the proposed method are established with defocusing amount as the unique variable. The verification of linewidth model was carried out on CCD with laser wavelength of 632.8 nm and objects of numerical aperture 0.1, and it shows that the experimental result is in good agreement with that by theoretical model. The proposed method is of great significance for fabrication of high-stability diffractive optical elements..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1730 (2008)
Design and Analysis of Novel Planar Integrated Optical Correlator
Liu Jiayong, Xu Ping, Xu Haidong, Zhang Xulin, Wang Bing, and Yang Jing
Novel planar folding optical correlator is proposed by means of micro-optical and binary optical techniques. The Fourier transform lenses, holographic matched filter, input plane and output plane are integrated on a common planar element. A reflective planar optical system is constructed by the correlator and a planar Novel planar folding optical correlator is proposed by means of micro-optical and binary optical techniques. The Fourier transform lenses, holographic matched filter, input plane and output plane are integrated on a common planar element. A reflective planar optical system is constructed by the correlator and a planar polarized mirror. The system structure and parameter design of this planar system are described, and a concrete model is proposed, with its volume reduced to about 12 cm3. At last, image recognition process of this correlator is simulated by using Fresnel diffractive method and gains excellent results, which proves the recognition capability of the system..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1735 (2008)
Lasers and Laser Optics
Experimental Study of Single-Longitudinal-Mode Brillouin Erbium-Doped Fiber Laser
Chen Wei, Zhang Yan, Ren Min, Xie Liang, Yuan Haiqing, Wang Xin, and Zhu Ninghua
A single-longitudinal-mode (SLM) Brillouin erbium-doped fiber laser (BEDFL) with multiple-ring cavities (MRC) and fiber Bragg grating tunable filter (FBG-TF) is proposed and demonstrated. The fine structure of optical spectrum is measured by observing the laser beat signals in the experiment, and effects of Brillouin gA single-longitudinal-mode (SLM) Brillouin erbium-doped fiber laser (BEDFL) with multiple-ring cavities (MRC) and fiber Bragg grating tunable filter (FBG-TF) is proposed and demonstrated. The fine structure of optical spectrum is measured by observing the laser beat signals in the experiment, and effects of Brillouin gain, FBG-TF, and MRC on the single-mode output are discussed, respectively. The output characteristic curve and wavelength stability test chart are given. The single-mode output power of 4 dBm with the signal-noise-rate over 60 dB and linewidth of less than 1.5 kHz is achieved..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1740 (2008)
Model of Interaction between Metal Powder Particle and Laser Beam in Laser Cladding
Yang Nan, and Yang Xichen
In order to analyze the velocity and temperature of moving metal particles in coaxial laser cladding, and to study the influence of process parameters, the movement model and thermal model of moving metal powder particle were proposed. The simulated results show that the nozzle geometric structure, particle size and inIn order to analyze the velocity and temperature of moving metal particles in coaxial laser cladding, and to study the influence of process parameters, the movement model and thermal model of moving metal powder particle were proposed. The simulated results show that the nozzle geometric structure, particle size and initial velocity of the shield gas /powder two-phase flow are important parameters to affect movement behavior of the powder particles, and the nozzle geometric structure, position of laser beam focual point, divergent angle, laser power, particle size and initial velocity of the shield gas /powder two-phase flow are important parameters to affect thermal behavior of the powder particles. Under the same process parameters (the inner radius of nozzle exit r=2 mm, the nozzle angle α=60°, initial gas velocity v0=0.8 m/s), based on digital particle image velocimetry (DPIV), the movement model of 316L stainless steel powder particle was proved by experiment. Results show that the movement model is reliable, and it is an efficient tool to understand the movement behavior of metal powder particles in coaxial laser cladding, and the thermal model is also an important tool to analyze the temperature change of powder particles with different parameters..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1745 (2008)
Materials
Thermal Characteristics and Optical Band Gap Properties of TeO2-TiO2-Bi2O3 Glasses
Wang Yanling, Dai Shixun, Xu Tiefeng, Nie Qiuhua, Shen Xiang, and Wang Xunsi
A series of TeO2-TiO2-Bi2O3 glasses were prepared by using conventional melting and quenching method. Their densities, transition temperatures, crystallization temperatures, refractive indices, absorption spectra were measured. The allowed direct transition and indirect transition, and Urbach energy of samples were calA series of TeO2-TiO2-Bi2O3 glasses were prepared by using conventional melting and quenching method. Their densities, transition temperatures, crystallization temperatures, refractive indices, absorption spectra were measured. The allowed direct transition and indirect transition, and Urbach energy of samples were calculated according to classical Tauc equation. The relationships between thermal stability and glass compositions were discussed. The effects of molar refraction、 metallization criterion, optical band gap, Urbach energy, contents of TiO2 and Bi2O3, and optical basicity on refractive indices of glass samples were also discussed . The results show that the TeO2-TiO2-Bi2O3 glass system has good stability. With the increase of molar refraction the refractive index increases, optical band gap and metallization criterion shrink. Meanwhile, the high third-order non linearity is associated with high optical basicity..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1751 (2008)
Ideal Model of Polymer Dispersed Liquid Crystal for Enhanced Scattering
Yu Tianchi, Fan Zhixin, Zhang Cuiyun, and Li Jing
The new progress of polymer-dispersed liquid crystals technology is introduced, and the enhanced scattering of liquid crystal micro-droplets is studied by optical principle. The criterion is proposed for both the optimum distance and the optimum diameter of liquid crystal micro-droplets, respectively. Using the two criThe new progress of polymer-dispersed liquid crystals technology is introduced, and the enhanced scattering of liquid crystal micro-droplets is studied by optical principle. The criterion is proposed for both the optimum distance and the optimum diameter of liquid crystal micro-droplets, respectively. Using the two criteria, the condition of reflection increasing film for the optical thickness of polymer located at the spacing of the adjacent liquid crystal micro-droplets, and the condition of birefringence destructive interference for the diameter of liquid crystal micro-droplets are satisfied. The method of calculating the optimum mixture ratio of polymer and liquid crystal is proposed, and the results are given according to the space filling efficiency of atomic packed in crystallology. With an ideal model of enhanced scattering of polymer-dispersed liquid crystals, the anomalous scattering computation and experimental results for the liquid crystal micro-droplets diameter, and the mixture ratio of polymer and liquid crystal are explained theoretically in the simple and clear ways..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1757 (2008)
Nonlinear Optics
Experimental Research of Cascading Nonlinear Effect in BBO Crystal
Wang Yanling, Li Xian, Zhou Xugui, Wu Hong, Xu Shixiang, and Ding Liangen
The sum frequency , difference frequency and corresponding cascading nonlinear effect were reported with 800 nm and 400 nm femtosecond light beams satisfying the phase-matching condition in BBO crystal. We obtain sum-frequency 267 nm and difference-frequency 800 nm waves simultaneously, taking account of phase matchingThe sum frequency , difference frequency and corresponding cascading nonlinear effect were reported with 800 nm and 400 nm femtosecond light beams satisfying the phase-matching condition in BBO crystal. We obtain sum-frequency 267 nm and difference-frequency 800 nm waves simultaneously, taking account of phase matching of sum frequency and difference frequency. The laser pulses are with 10 Hz repetition rate, 800 nm central wavelength, 60 fs pulse width and 7 mm spot diameter. The 10 mJ output energy of the Ti∶sapphire regenerative amplifier are split into two beams, and 70% energy is frequency doubled to 1.45 mJ of 400 nm by the first nonlinear crystal BBO and then injected into the second one with 3 mJ, 800 nm laser beam. For both of them there exists a small amount of detuning. When the new pulses mix frequency with input waves further, one-dimensional array of more than 10 beams including ultraviolet, visible bands can be observed. The mechanism and influencing factors of the input light intensity, chirp, relative time delay on the cascading nonlinear effect are investigated in details..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1761 (2008)
Spectral Shaping in High-Power Nd∶Glass Chirped Pulse Amplification System
Zhang Ying, Wei Xiaofeng, Zhu Qihua, Xie Xudong, Wang Fengrui, Zeng Xiaoming, and Ying Chuntong
In order to obtain a shorter pulse in a chirped pulse amplification system, the spectrum of the seed pulse is shaped to compensate the effect of gain narrowing, to make sure the amplified pulse has enough spectral width and given distribution. Supposing the spectral distribution of the chirped pulse after amplificationIn order to obtain a shorter pulse in a chirped pulse amplification system, the spectrum of the seed pulse is shaped to compensate the effect of gain narrowing, to make sure the amplified pulse has enough spectral width and given distribution. Supposing the spectral distribution of the chirped pulse after amplification is be Gauss or super-Gauss distribution, the inverse calculation on 100 J Nd∶glass chirped pulse amplication system is carried out. It is found that the energy, bandwidth of the seed pulse and the signal-to-noise ratio of the compressed pulse are strongly related to the distribution of the amplified pulse spectrum. After spectral shaping, the amplified pulse spectrum is second-order super-Gauss distribution, and 400 fs pulses are obtained with high signal-to-noise ratio, 33 μJ seed pulse energy and 14 nm bandwidth. The results provide a theoretical base for the spectral shaping experiment of 100 J system..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1767 (2008)
Optical Devices
Tunable Filters Based on Spilt-Ring Resonaor and Its Electromagnetic Band Gap
Li Haiyang, Zhang Yewen, Guo Jiyong, and He Li
Tunable filters with varactor-loaded spilt-ring resonant structure have been fabricated and the electromagnetic bandgap tuning is achieved. The varactor is positioned in a gap of a single split-ring resonator or between two split-ring resonators, and the filtering is tuned through capacitances modulation of the structuTunable filters with varactor-loaded spilt-ring resonant structure have been fabricated and the electromagnetic bandgap tuning is achieved. The varactor is positioned in a gap of a single split-ring resonator or between two split-ring resonators, and the filtering is tuned through capacitances modulation of the structure by adjusting the bias voltage applied to the varactor. The frequency response function of the filter to electromagnetic wave is numerically analyzed, and the physical principle of electromagnetic bandgap formation is explained. In order to eliminate the magnetic resonant effect and close the gap of split-ring resonator, experiments are carried out. It is found that the some bandgaps are resulted from magnetic resonance and some are resulted from electric resonance..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1772 (2008)
Research of Color Rendering of White LED Based on Red and Green Phosphors
Wu Haibin, Wang Changling, and He Sumei
White light emitting diodes (LED) are packaged based on blue LED dies surrounded by two different phosphors that emit red and green light respectively. First, the ratio of two phosphors maintains invariable, color rendering index achieves the maximal value in some color temperature, when it increases from 2700 K to 130White light emitting diodes (LED) are packaged based on blue LED dies surrounded by two different phosphors that emit red and green light respectively. First, the ratio of two phosphors maintains invariable, color rendering index achieves the maximal value in some color temperature, when it increases from 2700 K to 13000 K by degrees. Then, the ratio of two phosphors is changed gradually, by repeating above test, it is found that the color temperature corresponding to the maximal color rendering index is different at different phosphors ratio. The experimental results indicate that color rendering index can reach above 90 in any color temperature region from 2700 to 13000 K by matching the ratio of red, green phosphors and silica gel. Especially, color rendering index can achieve about 96 in the color temperature below 4000 K. Therefore, the maximal color rendering index in any color temperature can be obtained by the choice and match between blue LED dies, excitating and emitting wavelength, and the scale between them..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1777 (2008)
Night Vision Imaging System (NVIS) Compatibility of Cyanine Dye-Based NIR Absorbing Filter
Men Jinfeng, Chen Zhaohui, Cheng Haifeng, and Chu Zengyong
Near infrared (NIR) absorbing filter can be applied on lighting apparatus for night vision imaging system (NVIS)-compatible lighting. NIR absorbing filters were prepared by doping cyanine dye in polymethyl methacrylate (PMMA) filter to develop the NIR absorbing plastic filter for NVIS-compatible lighting. The influenceNear infrared (NIR) absorbing filter can be applied on lighting apparatus for night vision imaging system (NVIS)-compatible lighting. NIR absorbing filters were prepared by doping cyanine dye in polymethyl methacrylate (PMMA) filter to develop the NIR absorbing plastic filter for NVIS-compatible lighting. The influence of cyanine dye's dosage on the NVIS compatibility of the filters was studied. The results show that the transmittivity of visible light decreases gradually and the NIR absorbing capacity increases gradually with the adding of cyanine dye's dosage, and the NVIS Radiance decreased gradually towards meeting the needs of the NVIS-compatible lighting. A NIR absorbing green filter for NVIS-compatible lighting was achieved by utlizing the cyanine dye and common dyes(Yellow GS and Blue AP-FW) for plastic, the filter's color was NVIS green A and the filter's NVIS Radiance value was 9.22×10-12, which met the needs of the NVIS-compatible lighting in military standard, and the filter had excellent photostability..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1783 (2008)
Physical Optics
Evolution of Gauss Beam in Biased Centrosymmetric Photorefractive Media
Ji Xuanmang, Wang Jinlai, and Liu Jinsong
To investigate evolution of a Gauss beam and interaction of two Gauss beams in biased centerosymmetric photorefractive materials by applied electric filed, the beam propagation equation is solved numerically with a Gauss beam taken as the input wave.The result shows that a Gauss beam can evolve into steady-state screenTo investigate evolution of a Gauss beam and interaction of two Gauss beams in biased centerosymmetric photorefractive materials by applied electric filed, the beam propagation equation is solved numerically with a Gauss beam taken as the input wave.The result shows that a Gauss beam can evolve into steady-state screening bright soliton when the applied electric filed,intensity peak value and beam waist parameters match with the centrosymmetric photorefractive crystal respectively, or it will experience cycles of compression and expansion. It is also found that two same-phase beam attract each other and beams fusions occur at a certain interaction length. While in the case of anti-phase, the two beams repel each other with a force increasing monotonously with the decrease of initial separation..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1798 (2008)
Study of the Complex Number-Matrix Method on the Optical Properties of Cholesteric Liquid Crystal
Chen Ting, and Feng Shimeng
The cholesteric liquid crystal can be regarded as a multilayer which consists of many layer uniaxial thin films which exhibit optical rotation. For the convenient discussion of the optical properties of cholesteric liquid crystal a new 2×2 matrix is offered, whose matrix element is the complex exponential. We discThe cholesteric liquid crystal can be regarded as a multilayer which consists of many layer uniaxial thin films which exhibit optical rotation. For the convenient discussion of the optical properties of cholesteric liquid crystal a new 2×2 matrix is offered, whose matrix element is the complex exponential. We discuss this method in detail and the role of it in the investigation of the optical property of the cholesteric liquid crystal. It is concluded that if the wavelength of incident light is equal to pitch of the cholesteric liquid crystal, the linear polarized light is changed into the circular polarized light. We also study the mechanism of the selective reflection of cholesteric liquid crystal for visible light when light propagates along the cholesteric liquid crystal..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1805 (2008)
Quantum Optics
Remote Preparation of Qubit Via Tripartite Entangled W State in Cavity QED
Xiao Xiaoqi, and Yang Lianhua
Two schemes of remotely preparing an atomic state by using a tripartite entangled W state as the quantum channel in cavity QED are proposed. One is that the receiver reconstructs the original state based on the large-detuned interaction of a cavity field with two atoms, and the other is based on the resonant interactioTwo schemes of remotely preparing an atomic state by using a tripartite entangled W state as the quantum channel in cavity QED are proposed. One is that the receiver reconstructs the original state based on the large-detuned interaction of a cavity field with two atoms, and the other is based on the resonant interaction between a cavity and an atom. The two schemes involve one sender and two remote receivers, and the sender can help either one of the two receivers remotely reconstruct the original state with the assistance of the other receiver's single-particle orthogonal measurement. It shows that the scheme based on large-detuned interaction between atoms and cavity is insensitive to the decoherence of the cavity field, and thus the requirement on the Q factor of the cavity decreases. While in the other one based on resonant interaction betweenan atom and cavity, it is not necessary to introduce an auxiliary atom, so that the operations are more simple and convenient. But no matter which method is adopted, the total success probabilities of the both processes are equal..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1812 (2008)
A Novel Controllable Six-Well Optical Trap for Cold Atoms or Molecules and Optical lattice
Lu Junfa, Lu Heqin, Zhou Qi, and Yin Jianping
We propose a novel scheme to form a controllable six-well optical trap for cold atoms or molecules by using an optical system of a binary π-phase plate and a lens illuminated by a plane light wave. We calculate the intensity distribution of the six-well optical trap and discuss the evolution process of the optical trapWe propose a novel scheme to form a controllable six-well optical trap for cold atoms or molecules by using an optical system of a binary π-phase plate and a lens illuminated by a plane light wave. We calculate the intensity distribution of the six-well optical trap and discuss the evolution process of the optical trap from six-well to double-well or a single-well. The result shows that this six-well trap can be continuously changed into a double-well or single-well one by changed the π-phase plate..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1816 (2008)
Thin Films
Synthesis of Aligned Carbon Nanotubes Film by Plasma-Enhanced Hot Filament Chemical Vapor Deposition
Zhu Qingfeng, Zhang Haiyan, Chen Yiming, Chen Yuting, Chen Liechun, and Yang Dayong
Aligned carbon nanotubes (ACNTs) films are grown at low substrate temperature (500 ℃) by plasma-enhanced hot filament chemical vapor deposition (PE-HF-CVD) method. A gas mixture of methane, hydrogen and nitrogen is used as the reaction gas, with nickel particles prepared by spin coating nickel nitrate solution on silicAligned carbon nanotubes (ACNTs) films are grown at low substrate temperature (500 ℃) by plasma-enhanced hot filament chemical vapor deposition (PE-HF-CVD) method. A gas mixture of methane, hydrogen and nitrogen is used as the reaction gas, with nickel particles prepared by spin coating nickel nitrate solution on silicon, heat treatment and deoxidization with H2 as catalyzer. The carbon nanotubes prepared by 1 mol/l nickel nitrate solution are well aligned shown by scanning electron microscope (SEM) and transmission electron microscope (TEM) with 30～50 nm diameter, more than 4 μm long. Raman spectrum is used to display the carbon nanotubes film samples prepared by different concentrations of nickel nitrate solution..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1824 (2008)
X-Ray Optics
Microscopic Identification of Panax Quinquefolium and Panax Ginseng by X-Ray Phase Contrast Imaging
Xue Yanling, Xiao Tiqiao, Du Guohao, Liu Lixiang, Hu Wen, and Xu Hongjie
In the conventional microscopic identification of traditional Chinese medicines (TCMs), disadvantages, such as rigid sample preparations and adding extra reagents which may result in structure information loss limit its application. X-ray phase contrast imaging (XPCI) was introduced to study the microscopic identificatIn the conventional microscopic identification of traditional Chinese medicines (TCMs), disadvantages, such as rigid sample preparations and adding extra reagents which may result in structure information loss limit its application. X-ray phase contrast imaging (XPCI) was introduced to study the microscopic identification of Panax quinquefolium and Panax ginseng, in the aspects of clusters of calcium oxalate, vessels, cork cells, phloem and xylem rays. The experimental results show that XPCI method is convenient for microscopic identification. It is expected that XPCI will provide a new practical method for the identification of TCMs without any special sample treatments. The experiments also reveal that the phloem and xylem rays of Panax quinquefolium and Panax ginseng are obviously different. This microstructure difference may add another important basis for the microscopic identification of different ginsengs..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1828 (2008)
Application of Monolithic Capillary X-Ray Lens in Analysis of Single Aerosol Particles
Sun Tianxi, Xu Guangyu, Liu Zhiguo, Ding Xunliang, Zhu Guanghua, Sun Hongbo, and Liu Hui
X-ray fluorescence (XRF) analysis of single aerosol particles is a useful tool for identifying origins of aerosol particles. A micro-XRF spectrometer based on a monolithic capillary X-ray lens (MCXRL) and laboratory X-ray source is designed in order to carry out the XRF analysis of single aerosol particles. The order oX-ray fluorescence (XRF) analysis of single aerosol particles is a useful tool for identifying origins of aerosol particles. A micro-XRF spectrometer based on a monolithic capillary X-ray lens (MCXRL) and laboratory X-ray source is designed in order to carry out the XRF analysis of single aerosol particles. The order of magnitude of the gain of power density of the MCXRL is 103 at the focal spot, and the focal spot size of the MCXRL is about 30 μm. The minimum detection limit (MDL) of this spectrometer is 0.7 pg for the Fe-Kα. The XRF spectrum of a single aerosol particle with a diameter of 9 μm is obtained within 180 s when the working voltage and current of a Mo rotating anode X-ray generator are 30 kV and 50 mA, respectively. The experimental results show that the designed spectrometer has potential applications in the analysis of single aerosol particles..
Acta Optica Sinica
- Publication Date: Jun. 18, 2020
- Vol. 28, Issue 9, 1833 (2008)
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