Journals >Chinese Journal of Lasers
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2012
Volume: 39 Issue s2
42 Article(s)
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Research Article
A Single Aspheric Collimating Lens of the Laser Proximity Fuze
Zhang Xiangjin, Gan Lin, and Feng Ying
This paper investigates the problems of the large beam divergence angle and the short detection range in the launch system of laser proximity fuze. By analyzing the semiconductor lasers′ characteristics of the optical field and the characteristics of laser′s far-field divergence angle, according to aspheric optical desThis paper investigates the problems of the large beam divergence angle and the short detection range in the launch system of laser proximity fuze. By analyzing the semiconductor lasers′ characteristics of the optical field and the characteristics of laser′s far-field divergence angle, according to aspheric optical design theory, single aspheric collimation lens is designed by using Zemax. The simulation results indicate that the laser beam divergences are compressed to 5 mrad and 2 mrad respectively. The quality of the beam shaping increases effectively, and the emission beam divergence angle is reduced as well as the system range is improved..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 216002 (2012)
Improvement on the Lens Construction by Equi-Flux Map Method
Chen Chen, and Zhang Xiaohui
The precision of the lens construction by equi-flux map method should be improved. Firstly, the core of this method is analysed. The result shows that the geometric meaning of this method is the same as the Euler method in numerical method in solving differential equation. Then, based on Runge-Kutta method, the method The precision of the lens construction by equi-flux map method should be improved. Firstly, the core of this method is analysed. The result shows that the geometric meaning of this method is the same as the Euler method in numerical method in solving differential equation. Then, based on Runge-Kutta method, the method of lens construction of equi-flux map is improved. Two lenses which have 60° beam angle are designed in the same condition. These two lenses are simulated in the optical design software. The result of ray tracing shows that the illuminance distribution of the lens designed in the improved method is closer to the prescribed distribution. The improvement of the precision of the lens construction is achieved by this method..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 216003 (2012)
Design and Optimization of a Total-Internal-Reflection Prism in the Digital Micromirror Device Projection System
Li Dan, Yao Lianfang, Xu Xiyin, Cao Wen, Xue Yunyun, Guo Haicheng, and Zhang Baolong
Compared with the traditional total-internal-reflection (TIR) prism, the right-angle TIR prism is convenient to process. Meanwhile, it decreases 50% in the volume and 43% in the weight, which lowers the cost. Using the theory of optics the right-angle TIR prism is optimized in order to make it easier to process the strCompared with the traditional total-internal-reflection (TIR) prism, the right-angle TIR prism is convenient to process. Meanwhile, it decreases 50% in the volume and 43% in the weight, which lowers the cost. Using the theory of optics the right-angle TIR prism is optimized in order to make it easier to process the structure. In the optical software simulation, the system′s efficiency decreases from 53% to 48.3%, while its uniformity can be enhanced from 68% to 91%. It proves that the right-angle TIR prism is reasonable and practicable..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 216004 (2012)
Holography and Information Processing
Experimental Research of Range-Gated Active-Passive Image Fusion
Lu Wei, Wang Yan, Li Sining, Zheng Lei, and Wang Zehao
Range-gated imaging laser radars provide laser active image and passive image simultaneously. Data fusion of laser radar image and passive optical image is an implementation of complementary information, which can improve capability of target recognition and anti-interference. Laser radar image is fused with passive opRange-gated imaging laser radars provide laser active image and passive image simultaneously. Data fusion of laser radar image and passive optical image is an implementation of complementary information, which can improve capability of target recognition and anti-interference. Laser radar image is fused with passive optical image at pixel-level. The fusion strategy for the range-gated imaging radar and three-dimensional reconstruction are given. Data fusion of laser active intensity image and passive image retains rich information of passive optical image, and removes the background outside of the target. The data synthesis of the fusion image and range image provides a three-dimensional image. The experimental results show that the resolution of image fusion has been improved effectively while the range information of active image is retained with the methods above..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 209001 (2012)
Realization of the Discrete Fourier Transform Using a Parallel Optical Vector Matrix Multiplication Processor
Zhang Yuanda, Wang Bo, Chen Yixiu, Jia Hui, and Li Xiujian
Fourier transform is one of the keys of the mathematical tools in digital signal processing. The performance of traditional discrete Fourier transform based on digital circuit is restricted to the electronic device speed, which is difficult to meet the requirements of the high speed of signal processing, especially resFourier transform is one of the keys of the mathematical tools in digital signal processing. The performance of traditional discrete Fourier transform based on digital circuit is restricted to the electronic device speed, which is difficult to meet the requirements of the high speed of signal processing, especially restricting the development of Tbit/s super-speed optical processing technology. The discrete Fourier transform method based on the parallel optical vector matrix on time-multiplier principle is studied. The features of high speed and low heat dissipation of light are utilized and putting all optical parallel discrete Fourier transform method with phase only spatial light modulator as the core of transformation matrixes is put forward, which gets verifications by means of experiment. The experimental results show that the proposed all optical parallel discrete Fourier transform has less error (about 0.13). With further modulation and promotion of function, the method can have widely potential application in the high speed optical signal processing..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 209002 (2012)
Embedded Image Coding Based on Coefficient Clustering Discrete Cosine Transform
Zhang Libao, Yang Ning, and Zhu Tong
Discrete cosine transform (DCT) is an excellent transform because of its simple realization and high efficiency of compression. However, DCT cannot be combined with the fast and efficient zero-block coding algorithm perfectly. A new image coefficient distribution model using DCT is proposed based on the embedded zero-bDiscrete cosine transform (DCT) is an excellent transform because of its simple realization and high efficiency of compression. However, DCT cannot be combined with the fast and efficient zero-block coding algorithm perfectly. A new image coefficient distribution model using DCT is proposed based on the embedded zero-block coding algorithm. This model can make the same image coefficient distribution of DCT as that of discrete wavelet transform by coefficient clustering. During coding, the quadtree partitioning scheme of embedded zero-block coding is optimized. Experiment results show that the new algorithm can not only reduce the coding complexity, but also provides peak signal to noise ratio (SNR) performance better than baseline joint picture expert group (JPEG) at the same output bit rates..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 209003 (2012)
Large-Scale Face Recognition Using Optic-Electronic Hybrid Joint Transform Correlator
Guo Suoli, Cheng Panpan, Liu Yanfei, and Jia Hui
A new method for large-scale face recognition is proposed. In order to realize 1N identification, optical joint transform correlator is used to complete related calculation which consuming the largest time in image recognition, and electrical method is used to subtract power spectrum. By combining the computer pattern′A new method for large-scale face recognition is proposed. In order to realize 1N identification, optical joint transform correlator is used to complete related calculation which consuming the largest time in image recognition, and electrical method is used to subtract power spectrum. By combining the computer pattern′s high accuracy with the optical pattern′s high speed, the recognition′s speed and accuracy are improved. An evaluation criteria is also established to evaluate the recognition performance of this method. The computer simulation results show that the method can eliminate the central zero-order diffraction and sharp auto-correlation peak. When the recognition threshold value is in ［0.61,0.62］, both false match rate and false non-match rate are 0..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 209004 (2012)
Extraction Approach Based on Line Feature in Indoor Environment for Vehicle-Borne Three-Dimensional Acquisition System
Chen Chunpeng, Hu Shaoxing, and Zhang Aiwu
The location of vehicle-borne mobile mapping system (VBMMS) base on dead reckoning can effectively resolve the problem of the global navigation satellite system (GNSS) outages. Whereas, due to the accumulation of dead reckoning error, the VBMMS may result in large systematic positioning errors and serious impact the fiThe location of vehicle-borne mobile mapping system (VBMMS) base on dead reckoning can effectively resolve the problem of the global navigation satellite system (GNSS) outages. Whereas, due to the accumulation of dead reckoning error, the VBMMS may result in large systematic positioning errors and serious impact the final mapping accuracy when acquiring the space three-dimensional (3D) information. In this paper, the simultaneous localization and mapping (SLAM) is proposed to correct the location of VBMMS. The accurate feature extraction from the laser cloud points is the prerequisite for the robotic simultaneous localization and mapping. Considering the structure of indoor environment, a line feature extracting method based on the angle threshold is proposed. The novel method is implemented in the self-developed vehicle-borne 3D acquisition system and the experimental results demonstrate the validity of this method..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 209005 (2012)
Subpixel Centroid Error Analysis and Compensation for Optical Joint Transform Correlator
Zhang Xiaoya, Sui Jinggao, Tang Wusheng, Feng Chencheng, Jia Hui, and Li Xiujian
The accuracy displacement measurement system based on an optical joint transform correlator has widely potential application for its high speed and parallel computing.But its accuracy is restricted because of the centroid subpixel error. An optimal correlation peak extraction algorithm and a compensation algorithm, whiThe accuracy displacement measurement system based on an optical joint transform correlator has widely potential application for its high speed and parallel computing.But its accuracy is restricted because of the centroid subpixel error. An optimal correlation peak extraction algorithm and a compensation algorithm, which can be applied to the practical displacement measurement with the minor systematic error, are presented. Though simulation, experimental analysis and comparing the subpixel error effects based on weighted center of mass (COM), paraboloid fitting algorithms, Gaussian fitting, the best correlation peak extraction algorithm is COM with a weight degree of 2. The experimental data indicates that the residual error is declined from ±0.1 pixel to ±0.04 pixel through the new compensation algorithm, and the effection of subpixel error of the system is declined accordingly, and the displacement measurement accuracy of an optical joint transform correlator is improved..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 209006 (2012)
Restoration of Anisoplanatic Astronomical Image by Using Blind Deconvolution
Luo Lin, and Wang Li
The point spread function of atmospheric turbulence is space variant where the field-of-view of the ground-based optical telescope is greater than the isoplanatic angle. The effects of anisoplanatism in image degrade the image quality recovered by conventional image processing based on the imaging technique of the spacThe point spread function of atmospheric turbulence is space variant where the field-of-view of the ground-based optical telescope is greater than the isoplanatic angle. The effects of anisoplanatism in image degrade the image quality recovered by conventional image processing based on the imaging technique of the space-invariant point spread function. An approach is to partition the ansioplanatic image into sub-region images corresponding to the isoplanatic angle. The sub-region images are then reconstructed by the conjugate gradient blind deconvolution algorithm. To avoid ringing at the edges, a window function is used to smooth the image edges. After each sub-image is restored, the full image is assembled by the seamless split and overlapping. The experimental results suggest that the proposed approach is effective to improve the restored image quality from the anisoplanatic image degraded by atmospheric turbulence..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 209007 (2012)
Wavelet Denoising Algorithm Based on the Principle of Shearing Interferometry
Lin Chao, Qian Xiaofan, Li Bin, Li Xinghua, Shi Ying, and Liu Dan
It is one of the most important applications in holography to use hologram to obtain the phase information, and noise reduction is necessary in the process. The conventional denoising algorithms often cause fringe breaks and loss of phase detail when the phase of optical filed has high spatial variation frequency, thesIt is one of the most important applications in holography to use hologram to obtain the phase information, and noise reduction is necessary in the process. The conventional denoising algorithms often cause fringe breaks and loss of phase detail when the phase of optical filed has high spatial variation frequency, these problems can be reduced significantly through introducing shearing interferometry, but it has not been researched which denoising algorithm will get the best denoising result. Shearing median filter algorithm is compared with shearing wavelet denoising gorithm, which presents corresponding theoretical analysis, fulfills simulated calculation and experimental verification, and proves that the denoising result of wavelet denoising algorithm is the best..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 209008 (2012)
Method on Computer-Generated Hologram Coding and Digital Reconstruction of Multi-Object Waves
Chen Jiazhen, Zheng Zihua, and Lian Guiren
The methods on computer-generated hologram coding and digital reconstruction for descrete object wave are discussed and the frequency spectrum positions of zero-order image, original image and conjugate image are analized. The proposed coding and decoding scheme can separate the spectrum of each image and record multi-The methods on computer-generated hologram coding and digital reconstruction for descrete object wave are discussed and the frequency spectrum positions of zero-order image, original image and conjugate image are analized. The proposed coding and decoding scheme can separate the spectrum of each image and record multi-object wave data in the same computer-generated hologram. The simulation results show that the method by preprocessing the original object wave data and controling parameters to seperate effectively the frequency spectrum is simple and easy and the quality of the reconstructed image is good. As one of the coding parameters, carrier coefficient can effectively control the shift position of each spectrum component. Improper parameter setting can lead to be not able to extract effctive spectrum. So it can also be used as an encryption parameter..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 209009 (2012)
Single-Exposure Cepstrum Phase-Shifting In-Line Digital Holography Based on Dual-CCD
Lang Haitao, Pan Yun, Pan Weiqing, and Zhu Yongjian
Limited by the property of charge-coupled device (CCD), the recording optical path of in-line digital holography is commonly used to take full advantage of the CCD sampling space, which is in order to improve the performance of digital holographic measurement. But the reconstructed image of in-line digital holography iLimited by the property of charge-coupled device (CCD), the recording optical path of in-line digital holography is commonly used to take full advantage of the CCD sampling space, which is in order to improve the performance of digital holographic measurement. But the reconstructed image of in-line digital holography is overlapped by the direct wave and the conjugate image, which is hard to be separated. To achieve the real-time high-resolution measurement of in-line digital holography, the dual-CCD single-exposure cepstrum phase-shifting in-line digital holography is put forward, which is based on the single phase-shifting cepstrum technology. Then two key technical schemes of this technology, including the method of adjusting dual-CCD′s mirroring overlapping position and the optical structure of dual-CCD single-exposure π/2 phase-shifting, are given. Finally, the experimental results show that, the dual-CCD single-exposure cepstrum phase-shifting in-line digital holography can solve the overlapping problem well. Moreover, the real-time recording and reconstruction of in-line digital holography are initially realized..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 209010 (2012)
Study of Computer Simulation on Chiral Spiral Structure Based on Multi-Beam Interference Lithography
Niu Dongjie, Lü Hao, Zhang Qingyue, Zhao Qiuling, and Wang Xia
Based on multi-beam interference theory, the chiral spiral structure by interference lithography is simulated, and several factors that can influence the structures are discussed. The simulation results indicate that there are different special effects of incident angle, polarization status, polarization direction and Based on multi-beam interference theory, the chiral spiral structure by interference lithography is simulated, and several factors that can influence the structures are discussed. The simulation results indicate that there are different special effects of incident angle, polarization status, polarization direction and phase difference on the three-dimensional spiral structures. The computer simulation of photonic crystal provides an effective guidance for the experimental fabrication, and promotes the development and applications of chiral spiral structures..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 209011 (2012)
Laser Physics
Effect of Direct and Indirect Pumping on Nd3+-Activated Self-Frequency-Doubling Laser Performance
Huang Zhiyun, and Ren Xujing
In order to obtain best laser performance, the effect of the direct and indirect pumping ways on the laser output is studied theoretically. A self-frequency-doubling (SFD) laser model is developed. The calculated results are compared with the reported experimental results, and it verifies the validity of the model. BasIn order to obtain best laser performance, the effect of the direct and indirect pumping ways on the laser output is studied theoretically. A self-frequency-doubling (SFD) laser model is developed. The calculated results are compared with the reported experimental results, and it verifies the validity of the model. Based on the model, the Nd3+YAl3(BO3)4 (Nd3+YAB) SFD laser performance under the direct and indirect pump ways is studied theoretically. As the results show, for some Nd3+ concentrations and Nd3+YAB crystal length, the SFD laser power of direct pump is lower than that of indirect pump, and it implies that direct pump is not suitable for all samples. The criterion determining which sample is suitable for direct pump is given. By the similar process, the criterions for the different SFD crystals and experimental parameters could be derived..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 202001 (2012)
Diffraction Properties of Vector Random Electromagnetic Beam Induced by Ring
Lin Huichuan, Cai Jiajing, Pu Jixiong, and Rao Lianzhou
Based on the Huygens-Fresnel principle and the unified theories of coherence and polarization of partailly coherent beams, the diffraction properties of vector random electromagnetic beam transmitted through the ring aperture has been investigated. It is found that the intensity distribution, the degree of coherence anBased on the Huygens-Fresnel principle and the unified theories of coherence and polarization of partailly coherent beams, the diffraction properties of vector random electromagnetic beam transmitted through the ring aperture has been investigated. It is found that the intensity distribution, the degree of coherence and the degree of polarization of diffracted beams are related to the interception ratio of circular ring and initial coherence. The intensity distribution of vector random electromagnetic beam is chain structure by diffraction, and the chain structure gradually enlarges. If initial coherences of the incident beam in the x direction and y direction are equal, the degrees of coherence and polarization of the diffracted beam are same as intensity of light. On the other hand in the optical axis of the diffracted beams intensity distribution, degrees of the coherence and polarization exist oscillation. Moreover, when the intensity is maximum in optical axis of the diffracted beams, the degrees of coherence and polarization is minimal, and vice versa..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 202002 (2012)
Study of Self-Generated Magnetic Fields by Femtosecond Laser Plasma Interactions
A. Abudurexiti, and T. Tuniyazi
The occurrence and saturation of electromagnetic (EM) instability in femtosecond laser-plasma interactions are investigated using relativistic particle-in-cell (PIC) simulations. The linear and nonlinear saturations of EM instability are discussed. It is found that for plasma of non-Maxwell velocity distribution, the iThe occurrence and saturation of electromagnetic (EM) instability in femtosecond laser-plasma interactions are investigated using relativistic particle-in-cell (PIC) simulations. The linear and nonlinear saturations of EM instability are discussed. It is found that for plasma of non-Maxwell velocity distribution, the initial random thermal motions of electrons induce EM instability in plasma, and the resulting intense EM field causes the deposition of energy on electron beams in a very short distance and suppresses the energy transportation of super-thermal electrons formed by the ponderomotive force of the laser. This research benefits the understanding of mechanism of self-generated magnetic fields in inertial confinement fusion (ICF)..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 202003 (2012)
Red LED Light Source Generates Partially Coherent Vortex Beams
Cui Shengwei, Chen Ziyang, and Pu Jixiong
Partially coherent vortex beams are generated under the illumination of high power red-color light-emitting diodes (LED). The influence of the correlation property of partially coherent vortex beam, which can be modulated by adjusting the propagation distance, on the intensity distribution is studied. The effect of thePartially coherent vortex beams are generated under the illumination of high power red-color light-emitting diodes (LED). The influence of the correlation property of partially coherent vortex beam, which can be modulated by adjusting the propagation distance, on the intensity distribution is studied. The effect of the topological charge of vortex beam on the intensity is investigated as well. The experimental results are consistent with the theoretical simulations..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 202004 (2012)
Integrated Measurement and Analysis of Laser Energy Based on Virtual Instrument
Wang Dahui, Zhang Qijiang, Zhang Yongsheng, Zhao Xueqing, Zheng Guoxin, and Zhao Jun
Based on traditional energy measurement, an integrated acquisition and processing system of laser energy using energy detector, analog digital (AD) acquisition card and signal analysis system is established. Different calculation methods of ouput energy signal by laser interaction with different detectors using FlourieBased on traditional energy measurement, an integrated acquisition and processing system of laser energy using energy detector, analog digital (AD) acquisition card and signal analysis system is established. Different calculation methods of ouput energy signal by laser interaction with different detectors using Flourier transform is acquired. Different arithmetic is adopted related to different detectors. Energy signal processing software is compiled based on virtual instrument and its processing interface is designed. Synchronous measurement and processing of multi-channel lasers are achieved. The calibration of energy detectors and measurement of laser are accomplished by different energy algorithms for different detectors. Experiments show that the biggest energy error of the measurement system is less than 5% and the repetition of measurement is good, which can satisfy the demand of general detection. The method is handy and credible, which lays the foundation for integration and automation of laser system with energy measurement..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 202005 (2012)
Materials and Thin Films
Transmittance and Diffusivity of Volumetric Light Diffusers
Tang Zhenfang, Ye Qin, Yan Qizhen, Zhao Tingting, and Wei Hong
The transmittance and diffusivity are two key issues for light scattering materials but showing fairly sharp contradictions. A theoretical and computational model is derived to describe the volumetric diffusers based on multiple Mie scattering theory and Monte-Carlo methods. The scattering transmission processes of phoThe transmittance and diffusivity are two key issues for light scattering materials but showing fairly sharp contradictions. A theoretical and computational model is derived to describe the volumetric diffusers based on multiple Mie scattering theory and Monte-Carlo methods. The scattering transmission processes of photons are simulated with statistic calculation to optimize the correlation between the optical performances and parameters, including relative refractive index, size, concentration of doped particles, geometrical structure of diffusers, and wavelength of the illumination source. It is found that, relative refractive index is the most sensitive parameter in above to get perfect diffusers, the optimized values are 0.91~0.97 or 1.03~1.09. The wavelength dispersion of transmittance and diffusivity can be fatherly eliminated and suppressed to meet the needs of practical applications..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 206001 (2012)
Effect of Phase Separation Temperature on Photoluminescence Properties of Eu2+/Dy3+ Co-Doped High Silica Glasses
Jin Lei, Lei Xiaohua, Du Xiaoqing, Ren Linjiao, and Chen Weimin
High silica glass is a potential luminescence material in the future, whose photoluminescence properties are seriously influenced by phase separation temperature in the procedure. Porous glass with different phase separation temperatures and Eu2+/Dy3+ co-doped high silica luminescence glass with the same adsorption conHigh silica glass is a potential luminescence material in the future, whose photoluminescence properties are seriously influenced by phase separation temperature in the procedure. Porous glass with different phase separation temperatures and Eu2+/Dy3+ co-doped high silica luminescence glass with the same adsorption conditions are prepared. The specific surface area parameters of porous glass and the emission spectra of corresponding high silica luminescence glass are measured. The specific surface area measurement results indicate that the specific surface area of porous glass decrease firstly and then increase when the phase separation temperature is rising. The emission spectra of high silica luminescence glass indicate that the positions of characteristic peaks of high silica luminescence glass remain unchanged, while the emission intensity decreases firstly and then increases when the phase separation temperature is rising. Porous glass with phase separation temperature 620 ℃ has relative maximal specific surface area and corresponding high silica luminescence glass has the maximal emission intensity..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 206002 (2012)
Design of a Zoom Four-Mirror Optical System
Chen Jianfa, Wang Helong, Liu Xin, and Pan Zhifeng
When the infrared search and track (IRST) system is at work, the wide field of view (short focus) is used to achieve the target of wide-area search, and the narrow field of view (telephoto) to achieve the target of location and tracking. Compared with the refractive zoom system, the zoom four-mirror system has compact When the infrared search and track (IRST) system is at work, the wide field of view (short focus) is used to achieve the target of wide-area search, and the narrow field of view (telephoto) to achieve the target of location and tracking. Compared with the refractive zoom system, the zoom four-mirror system has compact structure and performs very well at thermalization and achromatism. It can meet the requirements of aerial vehicle IRST temperature adaptability, smaller size and lighter weight. A reflective zoom system design method based on the best least squares method and Seidel aberration is described. Instance is designed to prove the correctness and feasibility of this method. In the process of continuous zoom, the modulation transfer function of this optical system is close to the diffraction limit..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 216001 (2012)
Measurement and Metrology
Study on the Measurement of V-Belt Sliding Angle Using Optical Fiber Sensors
Guan Xiangyi
According to the creep test principle of friction of V-belt driving, the power transferred is closely related to the belt sliding angle. The deficiency of conventional formula for calculating the sliding angles is analysed, and an optimized formula is introduced. Tests that fiber optic sensors are used to measure the bAccording to the creep test principle of friction of V-belt driving, the power transferred is closely related to the belt sliding angle. The deficiency of conventional formula for calculating the sliding angles is analysed, and an optimized formula is introduced. Tests that fiber optic sensors are used to measure the belt sliding angles are carried out. Data acquisition is accomplished by high speed PCI interface card on computers in order to measure the magnitude of transient sliding angles. Then the sliding angle changes are correlated to the corresponding load conditions and an optimized formula for V-belt sliding angle calculation is obtained. It is found that the sliding angle calculated by the new formula is larger than by the traditional formula, but more approximate to the experimental values in both trend and magnitude..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 208001 (2012)
Aspherical Null Testing System for Extreme Ultraviolet Lithography Mirrors
Wang Liping, and Zhang Haitao
Calling for diffraction limited imaging performance, extreme ultraviolet lithography (EUVL) demands unprecedented requirements for figure metrology. The asphererical surface of EUVL mirrors must be measured with higher accuracy. Root mean square (RMS) is 0.2~0.3 nm. The design of interferometric null metrology is focusCalling for diffraction limited imaging performance, extreme ultraviolet lithography (EUVL) demands unprecedented requirements for figure metrology. The asphererical surface of EUVL mirrors must be measured with higher accuracy. Root mean square (RMS) is 0.2~0.3 nm. The design of interferometric null metrology is focused on, which can produce such highly precise figure of aspherical surfaces. The null lens is splited into a transmission sphere and a single lens. The errors introduced by the interferometer and the transmission sphere can be calibrated, and the error from the single lens can be rigidly controlled to guarantee the system testing accuracy. The residual aberration of the null testing system is controlled to be smaller than 0.003λ in the system. The main error sources of the null testing system are analyzed, the parameters of environmental control are proposed as well as limite residual aberration of the transmission sphere. Furthermore, the error sources are classified and the measurement accuracy of our aspherical null testing system is evaluated, RMS reaches 0.245 nm. It can meet the requirements of EUVL optics testing..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 208002 (2012)
A Method for Testing the Focal Length of Optical System with Small Field and Short Focal Length
Shao Jing, and Ma Dongmei
The high-magnification microscope objective lens (HMOL) have small field and short focal length. Measurement of this short focal length is difficult in a conventional way. The focal length of high-magnification microscope objective can be measured using multiple reference transfer based on magnification method. This meThe high-magnification microscope objective lens (HMOL) have small field and short focal length. Measurement of this short focal length is difficult in a conventional way. The focal length of high-magnification microscope objective can be measured using multiple reference transfer based on magnification method. This method is that an infinity design of low-magnification microscope objective lens (LMOL) is measured, the focal length of the LMOL is obtained, and then using the LMOL instead of collimator to measure the focal length of HMOL. This method is used to measure a Nikon metallographic objective lens (nominal focal length is 4 mm) and the errors are analyzed, testing accuracy is 0.0266 mm, and relative standard deviation is 0.664%. This fact that the choice of the objective lens used for reference transfer will affect the accuracy has been noticed, and a standard for choosing the appropriate benchmark objective is proposed..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 208003 (2012)
Optical Fiber Methane Gas Sensor Based on Fabry-Perot Cavity
Yan Haitao, Zhao Xiaoyan, Hao Hui, Zhen Zhiqiang, Zhang Zhi, Li Huijuan, Han Daofu, and Wang Ming
Based on Fabry-Perot (F-P) cavity interference, the fiber methane gas sensor system is studied. The micro-electromechanical systems (MEMS) technology is used to cladded cryptophane A polymer onto silicon-piece. The end faces of fiber constitute a F-P cavity. Based on the absorption of methane and gas-sensitive propertiBased on Fabry-Perot (F-P) cavity interference, the fiber methane gas sensor system is studied. The micro-electromechanical systems (MEMS) technology is used to cladded cryptophane A polymer onto silicon-piece. The end faces of fiber constitute a F-P cavity. Based on the absorption of methane and gas-sensitive properties of cryptophane A polymer, by analyzing the interference peak wavelength changes, the relationship between concentration and wavelength is obtained. Sensing mechanism is analyzed theoretically and by sensing performance is evaluated by methane gas sensing experiment the validity of the methane gas is verified by methane gas samples. By measuring and analyzing data the information included in the interference signal is demodulated. The results show that, the sensor has high sensitivity and reliability, and the response time is faster..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 208004 (2012)
Laser Ranging Algorithm Based on Robust Time Delay Estimation
Liu Wenhong
The laser ranging echo signals often contain impulsive noises, and have low signal-to-noise ratio, which make the traditional laser ranging algorithm performance decline, even if useless. This paper addresses a robust time delay estimation algorithm to laser modulation signal ranging. Signals with noises are modeled byThe laser ranging echo signals often contain impulsive noises, and have low signal-to-noise ratio, which make the traditional laser ranging algorithm performance decline, even if useless. This paper addresses a robust time delay estimation algorithm to laser modulation signal ranging. Signals with noises are modeled by using Alpha stable distribution. First, impulsive noises are suppressed and signal-to-noise ratio is improved by fractional lower-order convariance function. Then, the time delay information between echo signals and transmitting signals is obtained by using correlation function, so as to obtain the information of distance. Theoretical analysis and computer simulation results show that, the algorithm can be used for both echo signal containing Gaussian noises and impulsive noises. It has wide range of application and good practical value..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 208005 (2012)
Spray Droplets Size Distribution and Refractive Index Measurement Based on Rainbow Principle
Pan Qi
The measurement of spray droplets size distribution and refractive index rainbow principle is studied. A novel inverse algorithm is presented, which can inverse droplets size distribution and refractive index simultaneously. The new algorithm, based on regularized non-negative least squares method (NNLS) and regularizaThe measurement of spray droplets size distribution and refractive index rainbow principle is studied. A novel inverse algorithm is presented, which can inverse droplets size distribution and refractive index simultaneously. The new algorithm, based on regularized non-negative least squares method (NNLS) and regularization method, which adjusts the refractive index and size distribution range during the inverse process according to the main rainbow peak positon and ratio of ridge and peak rainbow intensity, can inverse both droplets size distribution and refractive index simultaneously without pre-knowledge of droplets diameter distribution function and range. The algorithm and also can avoid mutli-sulution problems. Simulation results shows that even the signal noise ratio (SNR) drops to 5 dB, the inverse results of droplets size distribution coincide with the supposed distribution in most situations. The method has a relatively good precision and reliability..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 208006 (2012)
Error Analysis of Adjusting and Alignment for Multiband Spectrometer of One Meter Solar Telescope
Fu Yu, Cheng Xiangming, Yuan Shu, and Xu Zhi
Based on the theory about the design of spectrometer and error analysis, a method about error analysis for system alignment is proposed. By using Zemax software, the alignment error on the image quality is analyzed. The result indicates that the tilt and tip of slit is less than 0.5°, then the coma involved can beBased on the theory about the design of spectrometer and error analysis, a method about error analysis for system alignment is proposed. By using Zemax software, the alignment error on the image quality is analyzed. The result indicates that the tilt and tip of slit is less than 0.5°, then the coma involved can be depressed by adjusting the collimating mirror; the self-rotating of slit less than 10″ can make the slant of spectrum lines less than one pixel; By adjusting the position of CCD, ±10 mm the defocus of collimating mirror is compensated. Then, the observed result is given..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 208007 (2012)
Auto-Testing Technology for Main Factors of Reliability of Monitoring CCD Camera
Chang Fei, Liu Jin, Xie Xingquan, Zhang Xuedong, Zhou Jing, and Guo Zhongping
In order to improve test efficiency and to evaluate reliability of monitoring CCD which is composed of CCD Camera and baffle that is customized as specified requirements, some appropriate testing method for main factors involved in reliability of monitoring CCD is proposed, as well as auto-testing model including comprIn order to improve test efficiency and to evaluate reliability of monitoring CCD which is composed of CCD Camera and baffle that is customized as specified requirements, some appropriate testing method for main factors involved in reliability of monitoring CCD is proposed, as well as auto-testing model including comprehensive evaluation function and auto-testing flow. More than two hundreds of monitoring CCD are used in Shenguang-Ⅲ (SG-Ⅲ) system now, to ensure high reliability of the whole system, every monitoring CCD should be tested carefully. The experimental results show that the proposed testing methods for main factors and auto-testing model are adequate to evaluate the reliability of monitoring CCD, and the average time of auto-testing is shortened evidently on comparison to that of manual testing method..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 208008 (2012)
Optical Communication
Impact of Film Thickness on Modes Reorganization of Coated Long Period Fiber Grating
Ou Qibiao, Peng Yulin, Zeng Qingke, Qin Zixiong, and Li Chuanqi
Based on the strict four-layer model, the modes reorganization of the coated long period fiber gratings (LPFG) appearing in the increase of film thickness is studied in details. The result shows that the periodic reorganization of coated LPFG occurs when the film thickness increases, and in each reorganization, a pair Based on the strict four-layer model, the modes reorganization of the coated long period fiber gratings (LPFG) appearing in the increase of film thickness is studied in details. The result shows that the periodic reorganization of coated LPFG occurs when the film thickness increases, and in each reorganization, a pair of adjacent cladding modes go into the film layer, guided by the thin film layer. But the cladding modes do not enter the thin layer synchronically. Every time HE modes go into the thin layer first, and pass some degree of thickness, and then it′s time for EH modes to enter the thin layer. In the process of reorganization, alternating current (AC) coupling coefficient varies greatly with the change of layer thickness. When HE modes go into the thin layer, AC coupling coefficient declines sharply; while EH modes go into the thin layer, AC coupling coefficient rises rapidly. Corresponding with the two adjacent modes in turn into the film layer, two jumps of the resonant wavelength of the coated LPFG occur in the process of reorganization. The research also indicates that, in reorganization, the refractive index sensitivity of the coated LPFG increases obviously, compared with the time before it is reorganized..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 205001 (2012)
Numerical Study of Supercontinuum Generation in Photonic Crystal Fibers with Two Zero Dispersion Wavelengths
Chen Haihuan, Chen Zilun, Zhou Xuanfeng, and Hou Jing
Supercontinuum generation (SC) in photonic crystal fibers (PCFs) with two zero dispersion wavelengths is investigated numerically, and the mechanism of SC generation in both normal dispersion region pumping and abnormal dispersion region pumping is analyzed. In order to investigate the effect of structure parameters, SSupercontinuum generation (SC) in photonic crystal fibers (PCFs) with two zero dispersion wavelengths is investigated numerically, and the mechanism of SC generation in both normal dispersion region pumping and abnormal dispersion region pumping is analyzed. In order to investigate the effect of structure parameters, SC generation in four different PCFs is analyzed. And the influence of two zero dispersion wavelengths is investigated. In addition, a method for SC control on spectral width and energy distribution by designing structure parameters is proposed..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 205002 (2012)
Surface Plasmon Resonance Sensing Characteristics Based on Photonic Crystal Fiber
Dong Li, Ren Guangjun, Hu Haiyan, Wu Yudeng, and Yao Jianquan
A simple photonic crystal fiber (PCF) model containing six large air holes in cladding is used. By introducing a small air hole in the core center, the effective index of the core mode is lowered. Therefore the tough problem of phase matching between core and plasmon modes in the surface plasmon resonance (SPR) sensor A simple photonic crystal fiber (PCF) model containing six large air holes in cladding is used. By introducing a small air hole in the core center, the effective index of the core mode is lowered. Therefore the tough problem of phase matching between core and plasmon modes in the surface plasmon resonance (SPR) sensor is resolved. At the same time, the analysis method based on loss spectrum is used to research the sensing effects of the parameters variation in the PCF SPR sensor. These parameters are optimized and the best structure of PCF SPR sensor is acquired. The sensitivity and resolution are also given. The maximum spectral sensitivity of the refractive index sensor is 0.075 μm. Its resolution reaches 1.33×10-4 if the spectrometer has a demodulation resolution of 1%. This sensor has a comparable resolution with other existing sensors, but it has much simpler structure..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 205003 (2012)
Stability of Reference Light Based on Fiber Bragg Grating in Brillouin Optical Time Domain Reflectometer System
Wang Jinrong, Fu Xinghu, Fu Guangwei, Zhang Xu, Zhang Huiyang, and Bi Weihong
In Brillouin optical time domain reflectometer (BOTDR) sensing system, it adopts optical coherent heterodyne detection to obtain spontaneous Brillouin scattering signal, making up for the lack of weak signal in direct detection. The system obtains the first-order optical wave of Brillouin frequency shift and the largesIn Brillouin optical time domain reflectometer (BOTDR) sensing system, it adopts optical coherent heterodyne detection to obtain spontaneous Brillouin scattering signal, making up for the lack of weak signal in direct detection. The system obtains the first-order optical wave of Brillouin frequency shift and the largest signal to noise ratio (SNR) with modulating LiNbO3 electro-optic intensity modulator by microwave source. But electro-optic intensity modulator is affected by many factors, resulting that SNR with the first-order optical wave of the reference light is low, which is heterodyne with the back Brillouin scattering light. Therefore, a new method of filtering reference light by fiber Bragg grating (FBG) is proposed, and the variation of SNR with the first-order side is analyzed. The experimental results show that the stable output of the first-order optical wave in a long time and Brillouin coherent signal with the maximum SNR can be obtained. The feasibility of the scheme is proved..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 205004 (2012)
Performance of Long-Range Loss-Mechanism Brillouin Optical-Fiber Time-Domain Analysis
Shen Yiming, Song Muping, and Dong Peijun
In the system of Brillouin optical-fiber time-domain analysis (BOTDA), stimulated Brillouin scattering signal which produced by the interaction of pulse pump and DC continuous wave (CW )probe light should be detected. According to the frequency difference between two optical waves, BOTDA systems can be made as two typeIn the system of Brillouin optical-fiber time-domain analysis (BOTDA), stimulated Brillouin scattering signal which produced by the interaction of pulse pump and DC continuous wave (CW )probe light should be detected. According to the frequency difference between two optical waves, BOTDA systems can be made as two types. One is the gain-mechanism, whose frequency of the pump pulse light is higher than the CW probe, and the other is the loss-mechanism, whose frequency of the pump pulse light is lower than the CW probe. In the gain-mechanism BOTDA, the sensing distance and the signal-to-noise ratio (SNR) are limited for the loss of pulse pump by the Brillouin interaction. The loss-mechanism BOTDA is studied by comparing the gain-mode BOTDA. The scheme of 100 km′s loss-mechanism BOTDA is set as the sensing system. It is found that the loss-mechanism BOTDA has better sensing distance and detecting performance than the gain-mechanism, and the worst SNR of the loss-mechanism is above 10 dB larger than the gain gain-mechanism under the same distance. So, the loss-mechanism BOTDA is a better choice for the long-range distributed optical-fiber sensing..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 205005 (2012)
Optimization of All Optical Wavelength Conversion System Based on Four Wave Mixing
Ning Fan, Sun Lingyu, Xi Lixia, Ma Yongxin, and Zhang Xiaoguang
All-optical wavelength converter can avoid wavelength conflict in wavelength division multiplexing channels, thus improving the transmission efficiency and increasing the network flexibility and capacity in all-optical networks. All-optical wavelength converter has become the research hotspot in recent years. SemiconduAll-optical wavelength converter can avoid wavelength conflict in wavelength division multiplexing channels, thus improving the transmission efficiency and increasing the network flexibility and capacity in all-optical networks. All-optical wavelength converter has become the research hotspot in recent years. Semiconductor optical amplifier (SOA) is the preferred choice for all-optical wavelength converter device. In the scenario of strict transparent all-optical network transmission, the all-optical wavelength converter utilizing the four-wave mixing effect of SOA is considered of greatest research value. A 40 Gb/s return-to-zero differential phase shift keying (RZ-DPSK) all-optical wavelength converter simulation system is built up based on four-wave mixing effect of SOA by OptiSystem software. With the aim to obtain higher conversion efficiency, higher optical signal-to-noise ratio and lower power penalty, the best parameters and best working environment are presented based on the discussion of the relationship among the parameters including injection current to SOA, wavelength detuning, signal and pump power..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 205006 (2012)
Application of a Novel Modulation Scheme of PS-RZ-QPSK Signal in High-Speed Optical Transmission System
Xu Lei, Zhang Yang′an, Zhang Jinnan, and Lin Mi
Modulation principle of dual-polarization quadrature phase shift keying (DP-QPSK) signal and polarization-switched quadrature phase shift keying (PS-QPSK) signal are demonstrated and advantages of PS-QPSK are proved in theoretically. A novel modulation scheme of PS-return-to-zero(RZ)-QPSK signal is proposed. The schemeModulation principle of dual-polarization quadrature phase shift keying (DP-QPSK) signal and polarization-switched quadrature phase shift keying (PS-QPSK) signal are demonstrated and advantages of PS-QPSK are proved in theoretically. A novel modulation scheme of PS-return-to-zero(RZ)-QPSK signal is proposed. The scheme reduces transmitter cost by less use of Mach-Zehnder modulator (MZM), but also presents similar performance as traditional structure for PS-RZ-QPSK. The simulation results indicate PS-RZ-QPSK can achieve a better transmission performance than DP-RZ-QPSK at the same bit rate (84 Gb/s) and baud rate (28 GBd), and prove the feasibility of novel modulation scheme..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 205007 (2012)
Remote Sensing and Sensor
Steering Accuracy Correction Algorithm of Liquid Crystal Phased Array Based on Slope Approximation
Zhou Yan, Kong Lingjiang, Pan Fei, Xiao Feng, and Ai Yue
Steering accuracy of liquid crystal phased array (LCPA) is effected by kinds of factors. The paper analyzes some important factors that affect steering accuracy of LCPA, and a steering accuracy correction algorithm is proposed. The algorithm uses approximate slope of phase in a single electrode instead of slope of fittSteering accuracy of liquid crystal phased array (LCPA) is effected by kinds of factors. The paper analyzes some important factors that affect steering accuracy of LCPA, and a steering accuracy correction algorithm is proposed. The algorithm uses approximate slope of phase in a single electrode instead of slope of fitting wave front to decrease difference between approximate slope and ideal slope in the way of adjusting voltage staircase constantly, that reduces accuracy error and improves steering accuracy. Simulation results show that normalized accuracy error can still be reduced by more than 95% under the condition of minimizing accuracy influences by reasonable parameter setting, and steering angle is improved significantly; Meanwhile the maximum phase delay can limit the range of phase realization and further effect performance of algorithm. Appropriate maximum phase delay can achieve phase accurately and enhance performance of algorithm..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 214001 (2012)
Nonlinear Response Characteristics of the Optical Frequency Modulated Lidar
Li Jiang, Lin Zhili, and Ma Jingjin
In optical linear frequency modulated continuous wave (LFMCW) lidar system, due to the limit of semiconductor laser performance, the ideal linear frequency modulation (LFM) signal cannot be obtained under a LFM electrical signal modulation in application, which makes beat frequency signal (BFS) distorted. Thus it is neIn optical linear frequency modulated continuous wave (LFMCW) lidar system, due to the limit of semiconductor laser performance, the ideal linear frequency modulation (LFM) signal cannot be obtained under a LFM electrical signal modulation in application, which makes beat frequency signal (BFS) distorted. Thus it is necessary to study the frequency modulated (FM) nonlinear response characteristics. The FM characteristic of semiconductor laser is analyzed and the FM nonlinear response formulas of lidar are derived. Discrete polynomial phase transform (DPT) algorithm is applied to estimate and compensate on the FM nonlinear parameters. And experimental platform is set up for validation. The experimental results show that the DPT algorithm can effectively estimate and compensate lidar FM nonlinear parameters and improve the accuracy of velocity and range..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 214002 (2012)
Distortion Assessment of Range-Gated Laser Imaging Based on Zernike Moment
Zheng Lei, Lu Wei, Li Sining, Wang Yan, and Wang Zehao
Range-gated lidar imaging has dislocation distortion in dynamic environment. An assessment criterion is introduced for lidar image with Zernike moment invariants. Zernike moment invariant standard deviations of images under different imaging frame frequencies are calculated in dynamic imaging. The image distortion can Range-gated lidar imaging has dislocation distortion in dynamic environment. An assessment criterion is introduced for lidar image with Zernike moment invariants. Zernike moment invariant standard deviations of images under different imaging frame frequencies are calculated in dynamic imaging. The image distortion can be effectively indicated by the relative change of various moment invariant standard deviations. Laser imaging radar is simulated by Vega simulation platform and emulation image of range-gated imaging is obtained. Experiment image is obtained by imaging system and vehicular platform, which are built in our laboratory. Both experiment and simulation results show that if the imaging frequency is larger than 5 Hz the composite image has no distortion, and the image distortion can be evaluated effectively with Zernike moment invariants..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 214003 (2012)
Study of the Propagation Model for Large-Amplitude Internal Waves in Deep Sea
Jing Wang1, Kai Guo1, and and Junmin Meng2
An amplitude of internal solitary wave as high as 100 m has been reported in the South China Sea(SCS). Large-amplitude internal waves may cause severe damage to the ocean engineering and submarine. The fully-nonlinear Schrdinger equation (FNLS) that describes large-amplitude internal-wave propagation in deep sea is deAn amplitude of internal solitary wave as high as 100 m has been reported in the South China Sea(SCS). Large-amplitude internal waves may cause severe damage to the ocean engineering and submarine. The fully-nonlinear Schrdinger equation (FNLS) that describes large-amplitude internal-wave propagation in deep sea is derived from the governing equations of hydrodynamics by introducing the perturbation expansions with the assumption that the fluid is in a two-layer stratification system. This is a theoretical model for internal-wave dynamics, which is different from the well-known KdV series formula and BO equation. Moreover, a numerical simulation is carried out in the SCS. The results show that waveform and group velocity in evolution are in accordance with the MODIS images, so the model is suitable for simulating the large-amplitude internal-wave behavior in deep sea..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 214004 (2012)
Effects of Atmosphere Temperature, Humidity and Pressure for a Space-Borne Lidar Measuring Atmosphere CO2 Concentrations
Xie Yangyi, Liu Jiqiao, Jiang Jiaxin, and Chen Weibiao
The influences of atmospheric temperature, humidity and pressure uncertainties on space-borne integrated path differential absorption (IPDA) lidar measuring atmospheric column-averaged CO2 concentrations are studied. The column-averaged CO2 concentrations measurement principle and CO2 absorption cross section calculatiThe influences of atmospheric temperature, humidity and pressure uncertainties on space-borne integrated path differential absorption (IPDA) lidar measuring atmospheric column-averaged CO2 concentrations are studied. The column-averaged CO2 concentrations measurement principle and CO2 absorption cross section calculation method are presented. The influences of atmospheric temperature, humidity and pressure errors on retrieving CO2 concentrations around on-line CO2 absorption line are analyzed and simulations are implemented. For optimal IPDA lidar on-line and off-line wave number of 6361.2250 cm-1 and 6360.99 cm-1, the total column-averaged CO2 concentration measurement error is calculated to be 0.296×10-6 with temperature error of 1 K, humidity error of 10% and relative pressure error of 0.001. The result is important for retrieval of column-averaged CO2 concentration with high precision and lidar system parameters optimization..
Chinese Journal of Lasers
- Publication Date: Jan. 01, 1900
- Vol. 39, Issue s2, 214005 (2012)
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