共查询到20条相似文献,搜索用时 125 毫秒
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提出了一种实现高非线性光子晶体光纤(PCF)的新方法,即在空芯光子晶体光纤(HC-PCF)的纤芯空气孔中填充高折射率、高非线性折射率的液态物质三氯甲烷、甲苯、二硫化碳等。利用全矢量有限元方法分析了这种液芯光子晶体光纤的模式分布及色散性质,分析得出其零色散波长可在800 nm左右调节,因此可使中心波长800 nm的钛宝石飞秒脉冲激光在这种光子晶体光纤的反常色散区传输,有利于超连续谱的产生。而且由于填充后光子晶体光纤具有较高的非线性系数,较小功率的脉冲激光就可在几毫米长的这种液芯光子晶体光纤中得到频谱范围大于1000 nm的超连续谱。 相似文献
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光子晶体光纤中非线性传输的数值分析 总被引:4,自引:2,他引:4
利用数值方法求解了广义非线性薛定谔方程,模拟了飞秒激光脉冲在具有不同色散特性的光子晶体光纤(PCF)中非线性传输和超连续光谱的产生过程,分析了在反常色散区和正常色散区飞秒激光脉冲的非线性展宽机制,详细讨论了脉冲内拉曼散射(ISRS)、自陡峭(SS)效应以及高阶色散对超连续光谱产生的影响。分析结果表明.无论在光子晶体光纤的反常色散区、正常色散区还是在光纤的零色散点,脉冲内拉曼散射效应对长波波段的光谱展宽都具有重要的作用。讨论了高阶色散尤其是三阶色散对超连续光谱中反斯托克斯波的显著影响,合理地选择色散曲线,能够得到更宽更平坦的超连续光谱,表明了光子晶体光纤的可控色散特性的重要应用价值。 相似文献
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应用等效折射率模型研究光子晶体光纤 总被引:7,自引:4,他引:7
应用等效折射率模型研究了光子晶体光纤(PCF)的传播特性.介绍了光子晶体光纤的等效折射率模型.通过求解标量波动方程得到了光子晶体光纤包层基空间填充模的模式折射率,利用阶跃光纤的理论来研究光子晶体光纤的导模特性.应用此模型对不同结构光子晶体光纤包层区的等效折射率与波长的关系进行了讨论.包层区等效折射率与芯子的折射率差随波长的增加而增大,并由此阐述了光子晶体光纤的单模特性.数值分析得到光子晶体光纤的基模的模式折射率,并由此研究了光子晶体光纤的波导色散与结构参量的关系.分析表明,光子晶体光纤的波导色散随空气孔孔距的变化符合Maxwell方程的比例性质.空气孔的相对孔径对波导色散有重要的影响.这些分析表明光子晶体光纤具有可以灵活设计其色散特性的潜在应用前景. 相似文献
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基于光子晶体光纤的全光开关实验研究 总被引:2,自引:2,他引:2
在10Gb/s光传输系统中进行了以光子晶体光纤(PCF)为非线性介质的全光开关实验研究。实验中高强度光脉冲经过非线性系数为普通常规光纤36倍的25m长光子晶体光纤后,观察到了由于自相位调制效应(SPM)而导致的光谱展宽现象。实验进一步研究了基于这一效应的全光开关特性,并得到了很好的开关特性曲线。同时还发现这种全光开关具有全光波形整形和波长变换的功能,在实验中变换脉冲中心波长偏离入射脉冲波长4nm。实验结果表明,这种具有高非线性系数的光产品体光纤非常有利于器件的小型化和集成化。 相似文献
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Analysis and Design of Photonic Crystal Fibers Based on an Improved Effective-Index Method 总被引:3,自引:0,他引:3
Li H. Mafi A. Schulzgen A. Li L. Temyanko V. L. Peyghambarian N. Moloney J. V. 《Lightwave Technology, Journal of》2007,25(5):1224-1230
The modal characteristics of photonic crystal fibers (PCFs), with guiding cores consisting of one or seven missing airholes, are investigated with the finite element method and compared to those of step-index fibers (SIFs). To extend the applicability of the classical SIF theories to PCFs, the effective refractive index of photonic crystal cladding and the effective core radius of a PCF are studied systematically, based on simple physically consistent concepts. With the new effective cladding index and core radius of PCFs, the classical definition of the V parameter for SIFs is extended to PCFs, and a highly efficient approach based on the effective-index method is developed for the design of PCFs. The new design approach has been successfully employed to analyze the modal properties of PCF lasers with depressed-index cores and further tested by using it to effectively estimate the number of guided modes for PCFs with large cores 相似文献
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为了准确估计实际光子晶体光纤(photonic crystal fibers,PCFs)的光特性,提出一种基于Contourlet变换的压缩感知重建方法来重建实际PCFs的截面,进而对实际PCFs的光特性进行快速评估。结合全变差去噪方法,对经典图像、商用大模场面积PCF和保偏PCF的光特性进行评估,结果表明,提出的方法可以有效保留PCFs截面空气孔多尺度多方向的特征,光特性的评估结果与产品参数相吻合。这也是目前首次将基于Contourlet变换的压缩感知应用于PCFs的光特性估计,研究工作为实际PCFs光特性的快速准确估计提供了有效的手段。 相似文献
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应用多极法理论计算了低折射率芯光子晶体光纤(PCF)基模的损耗并与未掺杂芯PCF进行了比较,发现可以从损耗的角度来理解低折射率芯PCF的截止特性:传输波长靠近短波长时,模式的损耗会突然变大,从而导致基模截止;而处于长波长时,这种光纤的传输特性和普通PCF相类似。通过改变纤芯折射率的大小和包层中空气孔的大小,可以对光纤的截止波长进行调节。 相似文献
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CHI Hao ZHANG Xian-min SHEN Lin-fang 《光电子快报》2006,2(1):1-4
Photonic crystal fibers (PCFs) have attracted greatattentionin recent years due to their interesting proper-ties ,such as endless single-mode operation,unique dis-persion and nonlinear characteristics[1 ,2].It has been re-ported that PCFs offer a wide range of potential applica-tions ,such as 2Rregenerators ,optical parametric ampli-fiers ,dispersioncompensationandsuper-continuumgen-eration[3].Also called holey fibers or microstructure fi-bers ,PCFs are optical fibers possessing periodic a… 相似文献
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新型大模场光子晶体光纤传输系统及其传输特性分析 总被引:1,自引:0,他引:1
通过在多模光子晶体光纤的两端分别连接一根单模光子晶体光纤,对其选择合适的参数,形成一种可以实现低弯曲损耗、大模场单模传输的光纤传输系统。运用数值仿真,分析了该传输系统在模场面积、弯曲损耗、连接损耗等方面的特性。研究结果表明,多模光子晶体光纤与单模光子晶体光纤所组成的系统可实现有效的单模传输;工作波长为1064nm时,多模光子晶体光纤在直波导状态时的基模模场面积可达1593μm2;在弯曲半径低至10cm时,多模光子晶体光纤仍然可以保持低损耗传输。经过对多模光子晶体光纤结构参数的优化,其与单模光子晶体光纤的连接损耗降低至0.085dB。 相似文献
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We present a systematic scheme to achieve both high birefringence and low confinement loss in index-guiding photonic crystal fibers (PCFs), using a structurally-simple PCF with finite number of air holes in the cladding region. By increasing the size of the outermost-ring air holes in the cladding region, highly birefringent PCFs with low confinement loss can be successfully achieved. The design strategy is based on the fact that the modal birefringence of PCFs is dominated by the inner-ring air holes in PCF, which is verified by a full-vector finite element method with anisotropic perfectly matched layers. Numerical results show that modal birefringence in the order of 10-3 and confinement loss less than 0.1 dB/km can be easily realized in the proposed PCF with only four rings of air holes in the cladding region. We expect that such fibers will be much easier to be fabvicated than those with more air holes in the cladding region. 相似文献
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The various mode effective indices of the doped photonic crystal fibers (PCFs) are compared, the mode field distributions of the fundamental mode and the second-order mode are analyzed, and the single-mode condition is presented. The mode effective indices of large-core doped PCFs with different core indices and structure parameters are simulated by the finite element method (FEM). The relations of the core index with the fiber structure parameters of pitch, hole-to-pitch ratio and core diameter are obtained for single-mode propagation. In the design and fabrication of the doped PCF, we can adjust the core index and fiber structure parameters to achieve large mode area and single-mode propagation. 相似文献