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干涉光谱仪动镜倾斜误差容限分析 总被引:13,自引:8,他引:5
本文从调制度和相位误差角度,系统分析了双光束干涉光谱仪中,当光束孔径为圆形和矩形时,动镜运动过程中发生倾斜的影响,讨论了动镜倾斜容限以及减小动镜倾斜误差的方法. 相似文献
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分析了迈克尔逊干涉仪中动镜和定镜在圆形通光孔径情况下动镜在扫描过程中倾斜对干涉调制度的影响.为满足干涉调制度要求,理论计算发现动镜倾斜角度需控制在1″以内,对应的相位误差为±6.6°以内.为了解决此问题,使动镜和定镜保持准直,采用定镜动态校准系统对动镜倾斜误差进行校准.实验结果表明,校准后的XR和YR相位误差的均方根分别为1.02°和1.25°,满足系统要求.动态校准系统能够有效地校准动镜长距离运动过程中发生的倾斜误差,对高分辨光谱仪的设计和研制具有一定的指导意义. 相似文献
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转镜式光谱仪光程差和非线性的研究 总被引:5,自引:5,他引:0
对转镜式高速干涉光谱仪的基本原理进行了介绍,给出了无晃动和有晃动两种情况下,轴上和轴外光线的光程差公式,并对结果进行了初步分析,发现晃动将使光程差大小发生变化,但不改变轴上光线零光程差的位置.光程差的非线性是转镜式干涉仪的天生缺陷,它和转镜的折射率、工作角等参量有关,使非线性最小可得出最佳折射率为2.9左右,从光程差误差的容限可以计算出对工作角的要求,折射率为最佳时,工作角可达13.3°,根据对非线性的分析结果,给出了转镜主要参量选择的原则. 相似文献
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对反射转镜式干涉光谱仪的原理进行了介绍,从马吕斯定律和角反射体的反射特性入手,选择转镜反射面的旋转中心作为入射光束和出射光束等波面的参考点,对反射转镜式干涉光谱仪的光程差进行了分析计算,给出反射转镜式干涉光谱仪任意时刻光程差及最大光程差的一般表达式,分析影响最大光程差和光程差变化周期的因素,为反射转镜式干涉光谱仪的设计与研制提供理论指导。 相似文献
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空间外差光谱仪视场展宽棱镜设计理论与方法 总被引:1,自引:0,他引:1
空间外差光谱仪采用特定楔角的棱镜实现视场拓展是提高仪器通量和辐射灵敏度的重要手段之一。借鉴传统傅里叶变换光谱仪视场展宽基础理论,结合空间外差光谱仪的技术特点,研究了基于数值归纳方法进行视场展宽棱镜设计的理论依据和实现途径。分析了不同Littrow角和目标波数下视场展宽棱镜顶角的最优取值及最大视场展宽容限。结果表明数值归纳方法全面衡量各级次视场对相位差的影响给出视场展宽棱镜顶角的最优取值,与传统理论推导方法相比,沿色散主截面方向视场容限提高了10%~30%,且数值归纳方法设计空间外差视场展宽棱镜简单、直观,在设计过程中可同时分析仪器参数对视场展宽容限的影响。 相似文献
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Guided-Wave Two-Dimensional Acousto-Optic Scanner Using Proton-Exchanged Lithium Niobate Waveguide 总被引:1,自引:0,他引:1
Two-dimensional scanning of a 0.6328 mum guided-light beam has been realized using noncolinear acousto-optic (AO) coplanar Bragg diffraction together with colinear AO guided-mode to substrate radiation-mode conversion in a Z-cut Xpropagation LiNbO3 proton-exchanged (PE) waveguide. The two surface acoustic (SAW) waves utilized are at the center frequencies of 500 and 200 MHz, propagating in the Y and X axes, respectively. Two-dimensional scanning of approximately 720 resolvable light beam spots, namely, 18 40 (horizontal vertical) scanning, has been demonstrated using a light beam of 1.0 mm aperture. The total number of resolvable beam spots can be greatly increased from 720 by simply utilizing SAW transducers of larger bandwidth and a light beam of greater aperture. It should also be possible to significantly increase the diffraction efficiency from 3 % by optimizing the parameters of the PE waveguide and the SAWs. 相似文献
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A review of schemes for multiple access in fiber optic networks shows that a hybrid of wavelength and code division multiple access (WCDMA) combines the best features of both. In particular, the hybrid scheme retains the large information carrying capacity of wavelength division multiple access (WDMA) and flexibility of code division multiple access (CDMA). In this paper WDMA, optical CDMA (OCDMA), and WCDMA networks are discussed. In OCDMA networks, concept of incoherent and coherent coding including inverse decoding and matched filter is introduced. The delay performance of both WDMA and WCDMA networks, under the simple suboptimum access protocols based on cyclic search, is computed. It has been shown quantitatively that tuning delay significantly affects the delay performance of both WDMA and WCDMA networks. Futhermore, delay performance of WCDMA networks is always better than the WDMA networks for the same tuning delay, load, and number of users. 相似文献
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S. G. Nedel’ko M. A. Krysyuk A. L. Apanasenko L. N. Lymarenko Z. T. Moroz 《Journal of Applied Spectroscopy》1997,64(1):55-61
Results of a study of the effect of γ-radiation on the spectral luminescence properties of cadmium tungstate crystals doped
with silver, bismuth, and molybdenum cations are presented. Spectral characteristics of the nondnnnoped crystals are briefly
described. Absorption and photo and X-ray luminescence spectra of the crystals taken before and after exposure to γ-radiation
(5.5·104 Gy) are compared. It is found that the spectral characteristics of the crystals doped with silver, bismuth, and molybdenum
cations do not change markedly after the exposure. The relation between the type of impurity-induced defects, individual characteristics
of the impurity cations, and the character of the effect of γ-radiation on the spectral luminescence properties of impure
crystals is analyzed (preliminarily).
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 55–60, January–February, 1997. 相似文献
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A simple technique of pulse compression, based on the linear chirp compensation of self-phase modulation (SPM) spectra in dispersion shifted fibers, is demonstrated. The optimization procedure is carried out, for a short span of a single-mode fiber, using a parabolic law, which describes the behavior of the squared output pulse width versus the pump peak power in the case of Gaussian pulses. The experimental results give a minimum pulse duration of 233 fs, which is in good agreement with the model. Shorter and coherent pulses, down to 90 fs, have been obtained by inserting an interference filter at the optical output. 相似文献
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The Shanghai Synchrotron Radiation Facility(SSRF)booster ring,a full energy injector for the storage ring,is deigned to accelerate the electron beam energy from 150MeV to 3.5GeV that demands high extraction efficiency at the extraction energy with low beam loss rate when electrons are ramping.Closed orbit distortion(COD)caused by bending magnet field uniformity errors which affects the machine performance harmfully could be effectively reduced by bending magnet location sorting.Considering the affections of random errors in measurement,both ideal sorting and realistic sorting are studied based on measured bending magnet field uniformity errors and one reasonable combination of bending magnets which can reduce the horizontal COD by a factor of 5is given as the final installation sequence of the booster bending magnets in this paper. 相似文献
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We measure the waveform and phase curves of short optical pulses before and after transmission over different lengths of fibers by use of the pulse analyzer with the frequency-resolved optical gating (FROG),and numerically simulate pulse evolution under the experimental conditions.The nonlinear coefficient of the fiber is given by comparing the experimental results with the numerical ones.Difference between the experiment and numerical simulation is analyzed. 相似文献
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Resonance scattering of elastic spherical shell and cylindrical shell while the surrounding fluid medium has absorption is studied. The normal mode solution derived using exact elastic theory and the separation of variables is still applicable. However, the scattering form function has to be modified for the absorbing medium, otherwise the unreasonable result would be obtained. The backscattering form function in the absorbing medium is redefined, and the form function of elastic spherical and cylindrical shell with vacuum or solid matter filled is calculated in various absorption conditions. The results show that the absorption of surrounding fluid leads to notable attenuation of the coincidence resonances in the mid-frequency, but it has a little influence on the low-frequency resonance scattering induced by the filler inside the shell. 相似文献
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A versatile and low-cost single-beam self-referenced phase-sensitive surface plasmon resonance(SPR)sensing system with ultra-high resolution performance is presented.The system exhibits a root-mean-square phase fluctuation of ±0.0028.over a period of 45 min.i.e.a resolution of±5.2×10-9 refractive index units.The enhanced performance has been achieved through the incorporation of three design elements:a true single-beam configuration enabling complete self-referencing so that only the phase change associated with SPR gets detected,a differential measurement scheme to eliminate spurious signals not related to the sensor response,and the elimination of retardation drifts by incorporating temperature stabilization in the liquid crystal phase modulato .Our design should bring the detection sensitivity of non-labeling SPR biosensing closer to that achievable by conventional fluorescence-based techniques. 相似文献
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Ta2O5 films are prepared on BK7 substrates with conventional electron beam evaporation deposition.The effects of SiO2 protective layers and annealing on the laser-induced damage threshold (LIDT) of the films are investigated.The results show that SiO2 protective layers exert little influence on the electric field intensity(EFI)distribution,microstructure and microdefect density but increase the absorption slightly.Annealing iS effective on decreasing the microdefect density and the absorption of the films.Both SiO2 protective layers and annealing are beneficial to the damage resistance of the films and the latter is more effective to improve the LIDT.Moreover,the maximal LIDT of Ta2O5 films is achieved by the combination of SiO2 protective layers and annealing. 相似文献