共查询到20条相似文献,搜索用时 31 毫秒
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A comparison between three possible cavity configurations, the confocal cavity, the ring cavity and the Bragg cavity is presented for a millimeter FEL set within the high voltage head of an electrostatic accelerator. A simple mechnical design to make the Bragg cavity tunable is proposed. The usual theory of the sinusoidal Bragg corrugation, in cylindrical geometry, is extended to the rectangular corrugation and, further, the theory of the Bragg mirror is extended to rectangular geometry. The features of a Bragg mirror in cylindrical and rectangular geometry are compared. 相似文献
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Nai-Hsiang Sun Chia-Ming Hu Jung-Sheng Chiang Wen-Fung Liu Jiun-Jie Liau Shih-Chiang Lin 《Fiber and Integrated Optics》2014,33(1-2):47-55
AbstractThe experimental results of the radiation for second-order fiber Bragg gratings, which are made of a single-mode photosensitive fiber (PS-1500; Fiber-Core Corp.) and a single-mode fiber (SMF-28; Corning Inc.), by a phase mask writing fabrication technique are explored. For PS-1500 fiber Bragg gratings, the maximum radiation efficiency of ?23.5 dB at resonance λ = 1,539.34 nm with a very narrow bandwidth (about 0.02 nm) are measured from a 10-mm-diameter photo-detector, while for SMF-28 fiber Bragg gratings, the maximum radiation efficiency is ?34.6 dB (λ = 1,538.03 nm) with a bandwidth of 0.06 nm. The total efficiencies of the radiation are about ?16.8 dB for PS-1500 fiber Bragg gratings and ?28.1 dB for SMF-28 fiber Bragg gratings. 相似文献
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N. S. Ginzburg G. G. Denisov S. V. Kuzikov N. Yu. Peskov A. S. Sergeev V. Yu. Zaslavsky A. V. Arzhannikov P. V. Kalinin S. P. Sinitsky M. Tumm 《Radiophysics and Quantum Electronics》2005,48(10-11):748-761
Electrodynamic properties of two-dimensional-periodic Bragg structures of planar geometry are theoretically analyzed within the framework of the geometrical-optics approximation. Specific features of two-dimensional structures with different profiles, such as two-dimensional sinusoidal and “chess-board” corrugation and corrugation in the form of rectangular grooves, are studied. “Cold” testing of the Bragg structures in frequency ranges of 60 and 75 GHz is performed. The measured frequency dependences of the coefficients of reflection, transmission, and scattering in the transverse direction are in good argeement with the calculations. Existence of high-quality modes near the frequency of exact Bragg resonance is experimentally confirmed. 相似文献
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Compact superstructure fibre Bragg gratings for the generation of ultra-high speed optical pulse bursts are reported. The gratings are equivalent in response to multi-pass superimposed chirped fibre Bragg gratings (SI-CFBGs), but an arbitrary sequence of consecutive gratings can be replicated in a single fabrication step using a simple trigonometric amplitude-phase function. SI-CFBGs are fabricated in photosensitive optical fibre and the time-resolved reflection of a 10 GHz picosecond pulse train is measured via frequency-resolved optical gating and optical sub-harmonic sampling detection techniques. The experimental results are compared to the theoretically simulated grating response and good agreement is found. 相似文献
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Considering the presence of birefringence in Bragg gratings, the spectral polarization mode dispersion (PMD) and polarization dependent loss (PDL) induced power penalty of eye opening is examined for a network with cascaded Bragg gratings. It is shown that when the birefringence in the grating is less than 10−5, the induced power penalty is less than 0.1 dB for a network with up to 30 cascaded Bragg gratings. However, when the grating birefringence is on the order of 10−4, the induced power penalty can be as high as 5.6 dB for a network with 14 cascaded Bragg gratings. 相似文献
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根据在一般坐标系下均匀布拉格光纤光栅的传输矩阵,得到了取样布拉格光纤光栅的传输矩阵。利用傅里叶变换得到了取样布拉格光纤光栅的谐振方程。结果表明,在不考虑平均折射率变化的情况下,谐振峰的位置是由光栅的周期和取样周期共同确定的,与取样时的占空比、光栅长度和耦合系数没有关系。类似于物理光栅,取样布拉格光纤光栅也存在缺级现象,给出了出现缺级的条件。 相似文献
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多波长啁啾叠栅的矩阵分析 总被引:1,自引:0,他引:1
在分析多波长啁啾叠栅特征的基础上,提出了多波长啁啾叠栅的矩阵分析模型,采用矩阵分析模型对4波长和8波长啁啾叠栅的反射谱特性进行了理论分析,数值分析结果与实验结果非常一致.还首次数值模拟了波长间隔0.8 nm的16波长啁啾叠栅.此方法对多波长啁啾叠栅的设计和制作具有参考价值. 相似文献
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The one-dimensional problem of plane EM wave interaction with strongly nonlinear sinusoidal Bragg gratings is exactly solved using the new Method of Single Expression (MSE). The basic point of the method is the presentation of the electrical field in the modulated medium (Bragg grating) in the form of a single expression, contrary to the traditional counter-propagating waves approach. The spectral characteristics of linear Bragg gratings of different length are presented. The influence of loss or gain on the spectral characteristics of Bragg gratings is considered. The electrical field amplitude distributions along a grating at the wavelengths corresponding to the minima and maxima of reflectivity in the vicinity of the Bragg resonance are illustrated. Bistable and multistable dependences of reflectivity on the incident electrical field amplitude are obtained for negative and positive nonlinearities. 相似文献
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Owing to the second-order fiber Bragg grating possessing narrower reflectivity bandwidth than first-order, an all-fiber spectroscopic filter with several second-order fiber Bragg gratings and optical fiber couplers in the visible region is designed to extract interest rotational Raman spectra. Considering the inference fringe visibility of inscribing fiber Bragg grating and the fiber core index dispersion effect, numerical simulations are made by the improved mathematical model based on an exponential photorefractive dynamic, and its simulative results show better agreement with the experimental data. We propose an all-fiber spectroscopic configuration, which could balance lidar sensitivity against signal-to-noise ratio for optimizing remote sensing performance by fiber Bragg gratings serially. Simulative results show that the thumb principle for fabricating second-order fiber Bragg grating is the increasing gratings length, and that this all-fiber spectroscope can achieve >70 dB suppression to elastic scattering and efficiently extract the rotational Raman signal for profiling atmospheric temperature. 相似文献
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利用矩阵分析法,针对两个相同光栅构成的光纤布拉格光栅法布里-珀罗(F-P)腔滤波器进行理论分析。数值模拟分析了光栅长度变化对光栅以及F-P腔滤波器反射特性的影响,指出光栅长度增加对反射特性影响的优缺点,分析利用常用切趾函数对光栅进行切趾,减小由于光栅长度增加导致反射谱的的旁瓣增大,对组成的F-P腔滤波器的反射特性的优化,得到了光栅切趾对F-P腔滤波器的反射特性的影响规律。对于在实际应用中制作出性能优良的光纤布拉格光栅F-P腔滤波器有一定的参考价值。 相似文献
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光纤 Bragg光栅的饱和效应可引起二阶衍射,并使一阶衍射的峰值反射率下降.本文利用折射率变化模型和耦合模理论,模拟了饱和情况下 Bragg光栅的一阶和二阶衍射谱,并讨论了饱和系数对一阶和二阶衍射的 Bragg波长和峰值反射率的影响.数值模拟结果与参考文献中的实验结果相吻合. 相似文献
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The anisotropic Bragg diffraction of the volume holographic gratings in photorefractive crystals are investigated based on the model of anisotropic coupled-wave theory. The effect of the initial intensity ratio and the recording angles of the two recording waves on the anisotropic Bragg diffraction properties is discussed. It is shown that both the ratio of the initial intensity and the incident angles of the recording waves are selective action for the anisotropic Bragg diffraction efficiency of the volume holographic gratings, while these two recording conditions are not selective action for the isotropic Bragg diffraction. Furthermore, the Bragg phase matching condition of anisotropic diffraction is analyzed when the recording angles change. 相似文献
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多模光纤光栅温度传感特性的实验研究 总被引:6,自引:2,他引:4
利用氢敏化处理的多模光纤制作了多模光纤光栅,并对多模光纤光栅的温度传感特性进行了实验研究与理论分析,表明这种光栅三个反射峰的布拉格波长随温度变化均呈现出良好的线性关系,并且重复性相当好,同一光栅的各反射峰的理论温度灵敏度系数都等于0.01nm/℃,实验测得的温度灵敏度系数为0.0098nm/℃或0.0099nm/℃,与理论分析相当吻合,这些特性与单模光纤光栅的温度传感特性接近相同。因此可以用多模光纤光栅代替单模光纤光栅开发光纤光栅传感器,以降低成本;这一实验结果还可以作为对多模光纤光栅进一步深入研究的参考。 相似文献
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A novel intra-cavity fiber laser system is demonstrated for multi-point gas detection. The laser uses fiber Bragg gratings as wavelength-selective cavity mirrors and a tunable filter to tune the operating wavelength to the Bragg wavelength of a selected Bragg grating. The Bragg wavelengths of the gratings are chosen to be aligned to different absorption lines of a gas or gases, allowing gas concentrations at multiple locations to be determined. 相似文献
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JosÉ Capmany Daniel Pastor Beatriz Ortega Jose Luis Cruz Miguel V. AndrÉs 《Fiber and Integrated Optics》2013,32(4):483-494
Some of the work that has been recently carried outjointly by the Optical Communications Group of the Universidad Politécnica de Valencia and the Optical Fibre Group of the Universidad de Valancia on the applications of fiber Bragg gratings to microwave photonics is described. The paper investigates separately some applications of linearly chirped fiber Bragg gratings (LCFBGs) and uniform fiber Bragg gratings (UFBGs). 相似文献
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Zhongwei Tan Yanhua Wang Wenhua Ren Yan Liu Bin Li Tigang Ning Shuisheng Jian 《Optik》2009,120(1):9-13
The limitation of the system with dispersion compensation by chirped fiber Bragg gratings is investigated in this paper. The transmission distance of the system based on chirped fiber Bragg gratings surpasses 3000 km. The bit error rate (BER) of the system is below 10−9 for as long as 2000 km. The BER is about 10−7 at 3000 km and, when forward error correction (FEC) is added, zero BER can be achieved. It is the longest transmission system with dispersion compensation by chirped fiber Bragg gratings. 相似文献