共查询到20条相似文献,搜索用时 15 毫秒
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采用改进的全矢量有效折射率法和耦合模理论,研究了光子晶体光纤布拉格光栅长度、占空比、光栅周期与慢光的变化规律。结果表明当光栅长度和光栅周期不变时,随着包层空气孔占空比的增大,光栅的慢光峰值波长出现蓝移,且时延量逐渐减小;1.06 cm 长的光子晶体光纤布拉格光栅可以产生约52 ps 的线性时延;光栅长度越大,慢光时延量越大;优化结构参数,在光子晶体光纤布拉格光栅的时延谱的侧瓣附近会产生最大群速度为c/371 的慢光峰。 相似文献
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A. Cusano A. Iadicicco D. Paladino S. Campopiano A. Cutolo M. Giordano 《Optical Fiber Technology》2007,13(4):291-301
In this paper, the authors present new and complex configurations involving micro-structured fiber Bragg gratings (MSFBGs) as advanced devices for sensing and communications applications. First, the spectral behaviour of multi-defect MSFBGs is investigated with particular regards to the possibility to carry out multi-parameter sensor by a single sensing element. More defects along the grating permit the formation of more defect states inside the band-gap ruled by the multiple interaction of the signal reflected by the unperturbed grating regions modulated by the phase delays of the perturbations. Here, a practical case based on a two-defect MSFBG is taken into account, revealing the potentiality to perform dual SRI measurements with a single MSFBG device. Finally, a novel configuration has been considered involving a single-defect MSFBG coated with nano-sized coatings with higher refractive index compared to the cladding one. The presence of a high refractive index coating along the thinned region would induce the mode redistribution and the transition from core modes to overlay modes if coating features are properly selected. Here, sensitivity characteristics of the proposed device are analysed and significant improvement in the sensing performances have been obtained, including the possibility to tune the maximum sensitivity in the desired range. 相似文献
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Thermal stability analysis of UV-induced fiber Bragg gratings 总被引:2,自引:0,他引:2
The phenomenon of decay in UV-induced Bragg gratings is examined. Thermal stability of gratings with large and small index changes are studied and compared. The role of stabilization in enhancing the thermal stability of gratings is explained. Approaches to analyzing and predicting grating decay are reviewed and compared 相似文献
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Li PEI Tigang NING Fengping YAN Xiaowei DONG Zhongwei TAN Yan LIU Shuisheng JIAN 《中国光电子学前沿》2009,2(2)
By optimizing the fabrication process of the chirped optical fiber Bragg grating (CFBG), some key problems of CFBG are solved, such as fabrication repetition, temperature stability, group delay ripple (GDR), fluctuation of the reflection spectrum, polarization mode dispersion (PMD), interaction of cascaded CFBG, and so on. The CFBG we fabricated can attain a temperature coefficient less than 0.0005 nm/℃, and the smoothed GDR and the fluctuation of the reflection spectrum are smaller than 10ps and 0.5dB, respec-tively. The PMD of each CFBG is less than 1 ps and the dispersion of each grating is larger than -2600 ps/(nm·km). With dispersion compensated by the CFBGs we fabricated, a 13×10 Gbit/s 3100 km ultra long G.652 fiber transmission system is successfully imple-mented without electric regenerator. The bit error rate (BER) of the system is below 10-4 without forward error correction (FEC); when FEC is added, the BER is below 10-12. The power penalty of the carrier-suppressed return-to-zero (CSRZ) code transmission system is only 2.5 dB. 相似文献
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为了研究多波长啁啾光纤光栅叠栅的反射和时延特性,提出多波长啁啾光纤光栅叠栅的耦合模理论方法,得到波长间隔Δλ=1.6nm的4波长和8波长的啁啾叠栅的反射谱和时延特性的数值分析结果,并设计了波长间隔Δλ=0.4nm的8波长的啁啾叠栅,数值分析结果与实验结果非常一致.结果表明,多波长啁啾光纤光栅叠栅的耦合模理论是可靠的,可用来分析其各种特性,此方法对多波长啁啾叠栅的设计和制作具有重要的参考价值. 相似文献
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线性啁啾光纤布喇格光栅反射谱的数值模拟 总被引:1,自引:1,他引:1
为了研究线性啁啾光纤布喇格光栅的特性,并进一步把它用于光纤激光器上,介绍了线性啁啾光纤布喇格光栅的耦合模理论,采用4阶Runge-Kutta法和传输矩阵法结合控制变量法,对线性啁啾光纤布喇格光栅反射率与啁啾系数、半峰全宽与光栅长度、反射率与直流纤芯折射率改变量之间的关系进行了数值模拟。结果表明,线性啁啾光纤布喇格光纤可以展宽带宽。基于这个结论,提出了利用线性啁啾光纤布喇格光栅作为光纤激光器腔镜,使输出谱线展宽,从而可作为宽带光源使用的方案。 相似文献
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The paper studies a kind of improved photonic crystal fiber gratings fabricated by CO2 laser heating method. The effective refractive index of cladding induced by periodic air hole deformation is computed using multipole method, and the relationship between the effective refractive index and the collapse of air-holes is discussed, thereby the modulation expression of effective refractive index is obtained. The grating transmission characteristics are simulated. The results indicate that with the diameter of air-holes increasing from 3.3 mm to 3.7 mm, the resonance wavelength shows blue-shift, the resonance peak intensifies, and the bandwidth becomes narrow. As the collapse degree of cladding enhances, the resonance wavelength shows red-shift, the transmission increases, and the bandwidth tends to narrow. 相似文献
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《Optical Fiber Technology》2007,13(1):32-38
A novel and efficient approach is proposed to calculate transmission and reflection spectra of propagating core mode and higher-order cladding modes when the fiber Bragg gratings (FBGs) are modulated by acoustically induced microbending. Based on a matrix form of first-order differential equations and its eigen-values/vectors using similarity transformation method, coupled-mode equations modeling acoustically induced microbending in FBG with a thin cladding can be transformed into a simple mathematical formulation. This method would be straightforward and thus beneficial to solve directly multimode coupled equations in comparison with a previous used fundamental matrix method and a Runge–Kutta algorithm. This simple model provides us a good view of co-directional and contra-directional couplings caused by acoustically induced microbending through FBGs. 相似文献
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A comprehensive analysis of multichannel grating optimization strategies is presented. The central idea is in dephasing of partial gratings with respect to each other. This dephasing allows the utilization of ultraviolet-induced refractive index changes with maximum efficiency. The dependence of group delay ripple on optimization strategy, number of channels, and other grating characteristics is also briefly discussed. Finally, we discuss further generalization of the dephasing approach to the case of multichannel gratings with nonidentical spectral characteristics. 相似文献
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J.S. Leng Y.C. Lai W. Zhang J.A.R. Williams 《Photonics Technology Letters, IEEE》2006,18(16):1729-1731
A novel architecture for microwave/millimeter-wave signal generation and data modulation using a fiber-grating-based distributed feedback laser has been proposed in this letter. For demonstration, a 155.52-Mb/s data stream on a 16.9-GHz subcarrier has been transmitted and recovered successfully. It has been proved that this technology would be of benefit to future microwave data transmission systems. 相似文献
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A method of analyzing fiber-ring resonators which is based on the transfer matrix technique is presented. The method is described and used to analyze known structures and compound coupled-ring resonators. Application of these structures as demultiplexers in FDMA (frequency-division multiple-access) systems is discussed 相似文献
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We show that the dispersion of multiple fiber Bragg gratings can be obtained from a single low-coherence interferometric measurement. The individual gratings can be identified either from the spatial separation of the interferometric signatures or from the unique wavelength-reflection bands of the gratings 相似文献