共查询到19条相似文献,搜索用时 46 毫秒
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高双折射光子晶体光纤中均匀布拉格光栅的特性 总被引:4,自引:0,他引:4
研究了具有高双折射的光子晶体光纤(HB PCF)中均匀布拉格光栅(FBG)的光谱特性。利用紧凑的超格子模型,对光子晶体光纤的传输特性进行分析,研究正向传输和反向传输的模式之间的耦合规律,从而研究写入光子晶体光纤中的均匀布拉格光栅的特性。首先给出具有C6v对称性的零双折射光子晶体光纤中光纤布拉格光栅的布拉格波长λB随光纤结构参量的变化规律;然后分析一种高双折射光子晶体光纤中的光纤布拉格光栅的光谱特性,高双折射使两个不同偏振态的反射峰分开较大;最后分析了一种常用的双模双折射光子晶体光纤中光纤布拉格光栅的光谱特性,LP01模和LPe11模的两个偏振态对应的反射谱都由于高双折射而分开。 相似文献
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提出一种基于高双折射光子晶体光纤与光纤环的超宽带可调谐微波光子滤波器.以多波长光纤激光器作为光源,向高双折射光子晶体光纤内填充温敏液体,通过改变填充温敏液体的温度,高双折射光子晶体光纤可具有不同的双折射,得到不同波长间隔的激光,从而使微波光子滤波器具有不同的自由频谱范围.当温度的变化范围为20~80℃时,仿真测得微波光子滤波器自由频谱的变化范围为2.49~39.9GHz.引入光纤环构建级联型微波光子滤波器,滤波器的主旁瓣抑制比可提高到33.6dB,Q值可达到499,提高了滤波器的频率选择性. 相似文献
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FBG传感器对应变和温度的敏感体现在其反射光中心波长的变化上,因此如何测量波长的变化就成为FBG传感器的关键。在光纤光栅的多种解调方法中,因滤波法的测量器件制作简单,测量系统简易、方便直观而被广泛应用。主要介绍了8种基于滤波法的解调方法,对它们各自的成本、检测精度、测量范围、器件制作以及适用的环境进行了详细的比较,分析了它们的优缺点,以便于在不同的检测条件下选用最佳的解调方案。重点介绍了光学小波滤波解调法,探讨了其测量系统的原理,并指出该方法可用于微弱信号的检测与处理。 相似文献
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根据比尔-朗伯定律, 设计了一种用于检测瓦斯气体浓度的新型光纤瓦斯传感系统。该系统利用光纤布拉格光栅优良的窄带滤波特性来产生差分吸收测量所需的窄谱光信号, 具有光路全光纤化、结构简单的特点。采用非球面光纤准直器构成光纤瓦斯传感探头, 提高了探头的光学稳定性, 进一步提高了测量灵敏度和测量稳定性。实验数据及结果表明, 系统具有良好的稳定性, 其测量灵敏度可达0.01%的体积分数, 测量范围大于5%的体积分数。 相似文献
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We investigated the performance limitation of a frequency-tunable photonic microwave notch filter incorporating a chirped fiber Bragg grating (FBG) as a group delay line. In particular, we carried out theoretical and experimental studies to analyze the impact of the reflectivity ripple (RR) and group delay ripple (GDR) in the chirped FBG on the output notch performance. The results of experimental and theoretical analyses performed on a photonic microwave notch filter in which an S-bending-based linearly chirped FBG was incorporated, revealed that the notch depth and notch frequency were significantly affected by imperfections in the chirped FBG. The notch depth was found to be decreased by the RRs, whereas significant fluctuations in the notch frequency were caused by the GDRs. On the basis of the obtained results, we conclude that the RR and the GDR are the fundamental factors that degrade the performance of chirped FBG-based photonic microwave filters. 相似文献
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《中国光学快报(英文版)》2017,(8)
Investigation on the group delay performance of microwave photonic filters is presented. Analysis and simulation results show symmetrical distribution on the delayed optical signals in the impulse response is required to obtain a constant group delay performance. Experimental results for both symmetrical and asymmetrical tap distribution microwave photonic notch filters are presented showing the group delay response with ?25 ps and around 1 ns ripples, respectively. 相似文献
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Apodization is a crucial technology for improving the dispersion performance of fiber Bragg gratings (FBGs). In this paper, we focus on how to select an optimal apodization for chirped fiber Bragg gratings and demonstrate a novel apodization selection method capable of choosing the optimal apodization based on the relationship between the bandwidth change and variation in average group delay ripple (GDR). Compared with current approaches, the novel method can select an optimal apodization profile and parameter for FBGs easily and accurately. Two numerical experiments are used to demonstrate the advantages of this method, one exhibits the different performances of five different apodization profiles, the other evaluates the influence of FBG parameters such as grating length, period, chirp, and index change on the apodization performance. 相似文献
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采样大啁啾光纤光栅理论(LCSBG)是实现超高信道数梳状滤波器的理想方案,但实际制作时存在信道间隔不准确、多信道无法同时对齐的问题,文中通过对多信道梳状滤波器反射谱特性的数值模拟分析以及信道间隔误差进行了理论计算,指出问题的来源为LCSBG 要求的光栅为周期倒数线性啁啾,并不是简单的线性啁啾.对此,提出了相移补偿方案,并以100信道,40 GHz 梳状滤波器为例进行了仿真验证,得到了理想的结果.这为实际制作高信道、高准确度的多信道梳状滤波器打下了良好的理论基础.
关键词:
光纤光栅
采样大啁啾
相移
多信道梳状滤波器 相似文献
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采样大啁啾光纤光栅理论(LCSBG)是实现超高信道数梳状滤波器的理想方案,但实际制作时存在信道间隔不准确、多信道无法同时对齐的问题,文中通过对多信道梳状滤波器反射谱特性的数值模拟分析以及信道间隔误差进行了理论计算,指出问题的来源为LCSBG 要求的光栅为周期倒数线性啁啾,并不是简单的线性啁啾.对此,提出了相移补偿方案,并以100信道,40 GHz 梳状滤波器为例进行了仿真验证,得到了理想的结果.这为实际制作高信道、高准确度的多信道梳状滤波器打下了良好的理论基础. 相似文献
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A novel free-spectral range (FSR) tunable Fabry-Perot filter (FPF) with two superimposed fiber Bragg gratings (SFBGs) is proposed and experimentally demonstrated. The SFBGs, initially uniform in period with slightly different Bragg wavelengths, were glued onto the lateral surface of a specially-designed cantilever beam and linearly chirped by beam bending-induced strain gradient. As a result, their reflection bands overlap and a grating-based FPF with a tunable FSR is formed. A continuously tunable FSR of 0.1-0.5 nm has been achieved in the experiment. 相似文献