共查询到19条相似文献,搜索用时 62 毫秒
1.
提出矩形波导近似,并分别采用Marcatili法和有效折射率法进行计算,得出了数值结果,并将其与大块光学材料近似、修正耦合波理论和微扰法以及精确求解特征方程的结果进行比较. 相似文献
2.
本文采用计算介质波导色散关系的叠代矩量法计算阶跃型椭圆光纤两个基本偏振模式的传播常数、几何双折射及群折射率差.本方法简便、有效,能给出与精确数值计算吻合的结果. 相似文献
3.
光纤偏振模色散的测量 总被引:11,自引:1,他引:10
光纤中的偏振模色散是限制高速光纤通信系统传输容量的极限因素,本文报道光纤偏振模色散的测量,对国内外多种光纤进行了测量比较,较长的单模非偏振保持光纤的多次测量值科克斯韦概率分布,同时发现国产的光纤质量有待改进,最后分析了一些实验中观察以的现象并作了解释和讨论。 相似文献
4.
就双模光纤具有零模色散的最佳折射率分布设计问题提出了一个新的数值计算方法,即将问题归为一类代数方程组反问题,给出了一个可行的牛顿迭代数值解法。 相似文献
5.
基于椭圆孔微结构纤芯的高双折射光子晶体光纤 总被引:2,自引:1,他引:1
提出了一种在纤芯引入微小椭圆孔实现高双折射光子晶体光纤的方法.采用全矢量有限元方法和完美匹配层条件,依次研究了光子晶体光纤在纤芯中引入单个、双个、三个微小椭圆孔情况下的双折射特性.模拟结果表明,纤芯微小椭圆孔主导了光子晶体光纤的双折射特性,其参量及个数对双折射有着重要的影响,增大椭圆面积、椭圆率可以进一步提高光子晶体光纤的双折射.最后设计和研究了一种采用三环阵列椭圆孔微结构纤芯的光子晶体光纤,其双折射可以达到2.7×10-3. 相似文献
6.
针对光子晶体光纤多零色散点、高双折射的应用要求, 设计了一种新型结构的光子晶体光纤, 其纤芯由位于菱形四个角上的圆形空气孔组成. 通过有限元数值分析方法对该种结构光子晶体光纤的色散特性和双折射特性进行数值仿真, 得到色散与波长、色散与纤芯圆孔尺寸、双折射与波长、双折射与纤芯圆孔尺寸的关系. 研究结果表明:在满足光纤传输功率要求的条件下, 光纤的双折射在d1<0.8 μupm 时的性能较好. 同时, 该种结构的光子晶体光纤在芯区直径满足d1=0.4 μupm或 d1=0.6 μupm时会出现两个零色散点, 这对进一步研制具有多零色散点的光子晶体光纤具有重要的意义. 相似文献
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基于超格子构造法,采用全矢量模型研究了具有中心缺陷孔的椭圆光子晶体光纤的传输特性。着重讨论了中心缺陷孔对光纤中基模的模场分布、双折射特性和色散特性的影响。研究表明:与椭圆孔光子晶体光纤相比。由于中心椭圆缺陷孔的引入,使该光纤具有更高的模式双折射。光纤的传输特性对光纤的结构参量和波长具有较强的依赖关系。随着波长和中心缺陷孔的增加。双折射将增大,其模式双折射在10^-3量级。改变光纤的结构参量,可以获得超宽带的色散平坦或异常的色散特性。分析结果显示,当中心孔的尺寸de/D=0.4时。在波长1.55μm附近,可获得近400nm的色散平坦区。 相似文献
10.
设计了一种新型近椭圆内包层(NEIC)结构的高双折射偏振保持光子晶体光纤(PCF),并利用带有各向异性完全匹配层吸收边界条件的全矢量有限元法(FEM)对这种光纤的特性参数进行了数值分析.结果表明这种结构的光子晶体光纤在1.55μm的双折射系数高达2.0×10-3,在长轴和短轴方向上的模场直径分别为9.2μm和2.4μm.同时当短轴方向最内层空气孔的孔径在1.30—1.18μm范围内变化时(孔径变化范围~10%),其双折射系数的劣化小于1.2×10-5,表明这种结
关键词:
光子晶体光纤
双折射
近椭圆内包层
偏振稳定性 相似文献
11.
Polarization characteristics of chiral photonic crystal fibers with an elliptical hollow core 下载免费PDF全文
The theoretical study of dielectric-chiral photonic crystal fiber(PCF)with an elliptical hollow core is presented.The band structure of chiral photonic crystal(PhC)is calculated by using a modified plane-wave expansion(PWE)method.By examining the out-of-plane photonic bandgaps(PBGs)of chiral PhC,a kind of chiral PCF with a hollow core is designed and their eigenstates are calculated.The distributions of mode field and polarization state are demonstrated,and how the structural asymmetry of the core together with the chirality in the background affects the modal polarization is discussed.The dependences of birefringence on chirality for different ellipticities of core are investigated. 相似文献
12.
R. K. Sinha 《Fiber and Integrated Optics》1996,15(2):125-133
Coupling characteristics of 4 × 4 elliptical core optical waveguide couplers that consist of four highly elliptical core fibers, whose centers form a rectangle, are obtained. The effect of the aspect ratio of the individual elliptical core fibers as well as that of their rectangular arrangement on the coupling characteristics have been obtained. It is shown that the state of polarization of the input signal through such a coupler is maintained. 相似文献
13.
本文设计了两种具有微结构纤芯的光子晶体光纤(PCFs)——矩形芯和椭圆芯PCFs,利用电磁场散射的多极理论研究了这两种光纤的基本特性.发现在光纤包层气孔不变的情况下,仅通过调节纤芯气孔的大小就可以灵活地调节光纤的双折射、色散和非线性特性.随着纤芯气孔半径r1的增大,两种纤芯结构的PCFs表现出如下特点:双折射度增大且最大双折射度对应的波长发生红移,零色散波长由一个增加到三个,短波段非线性系数增大而长波段非线性系数减小.r1=0.4 μm的椭圆芯PCFs的三个零色
关键词:
微结构纤芯光子晶体光纤
双折射
色散
非线性 相似文献
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本文将无源的不规则波导看作有源的理想波导,求等效极化电流电场,直接得到单一光波导模间耦合和辐射损耗问题的解。用这个方法计算了阶跃单模光纤折射率轴向不均匀变化的损耗。这种方法完全脱离了耦合波的概念,它不但物理意义明确,而且求解问题的方法简洁。最后以单模光纤弯曲和微弯损耗为例,说明等效电流方法还适用于广义耦合波理论才能求解的问题。 相似文献
16.
Polarization properties of elliptical core non-hexagonal symmetry polymer photonic crystal fibre 总被引:1,自引:0,他引:1 下载免费PDF全文
In this paper, polarization properties and propagation
characteristics of polymer photonic crystal fibres with elliptical
core and non-hexagonal symmetry structure are investigated by using
the full vectorial plane wave method. The results show that the
birefringence of the fibre is induced by asymmetries of both the
cladding and the core. Moreover, by adjusting the non-symmetrical
ratio factor of cladding $\eta$ from 0.4 to 1 in step 0.1, we find
the optimized design parameters of the fibre with high
birefringence and limited polarization mode dispersion, operating in
a single mode regime at an appropriate wavelength range. The range of
wavelength approaches the visible and near-infrared which is
consistent with the communication windows of polymer optical fibres. 相似文献
17.
Yoshihiro Ohtsuka 《Optical Review》2001,8(6):498-499
Optical-frequency dependent polarization mode dispersion as well as modal birefringence of three kinds of specially designed
hollow-induced birefringent single-mode fiber are measured over an optical frequency range between 345 and 410 THz by optical
frequency-domain interferometry. 相似文献
18.
P. Lesiak T. R. Woliński K. Brzdąkiewicz K. Nowecka S. Ertman M. Karpierz A. W. Domański R. Dąbrowski 《Opto-Electronics Review》2007,15(1):27-31
In this paper we present numerical and experimental results of propagation and polarization properties of the photonic liquid
crystal fibers (PLCFs) in which only selected micro holes were filled with nematic liquid crystal (LC) guest materials. As
a host photonic crystal fiber (PCF) structure, we used a commercially available highly birefringent PCF (Blazephotonics, UK).
A tunable laser operated at infrared has powered the PLCFs under investigation infiltrated by the 1550 nematic LC synthesized
at the Military University of Technology. Temperature induced changes of the polarization mode dispersion (PMD) as well switching
between fundamental and higher order modes and also single-core and two-core propagation were successfully demonstrated. 相似文献