共查询到20条相似文献,搜索用时 62 毫秒
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在采用阶跃有效折射率模型研究光子晶体光纤的可行性方面,提出了将普通单模光纤、色散位移光纤、色散平坦光纤作为一定极限条件下的折射率引导型光子晶体光纤特例的观点.通过编程计算,并与文献报道的实验数据对比,表明应用本模型可以揭示光子晶体光纤所具有的奇异的色散机理.特别是应用本模型具有更快的计算速度.还用本模型分析了空气孔直径、周期及芯径对色散特性的影响.
关键词:
折射率引导型光子晶体光纤
阶跃有效折射率模型
色散 相似文献
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等效折射率模型研究光子晶体光纤的色散特性 总被引:16,自引:4,他引:16
应用等效折射率模型对折射率导模光子晶体光纤的群速度色散特性进行了详细的讨论。由于光子晶体光纤由单一材料(SiO2)制成,光纤的波导色散决定了总色散,因此讨论中将群速度色散分解为波导色散和材料色散,研究了波导色散与光子晶体光纤的结构参量孔距∧、相对孔径f的关系。分析表明,在f一定的情况下,光子晶体光纤的波导色散与孔距∧的关系符合麦克斯韦方程的比例性质;而在孔距∧确定的情况下,光子晶体光纤的波导色散的零点、极小值点位置与f在所讨论的波长范围内存在线性关系。最后举例说明了通过调整光子晶体光纤的结构参量,可以灵活地设计其色散特性。 相似文献
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一维光子晶体非线性色散特性的分析 总被引:2,自引:8,他引:2
从无限周期一维光子晶体的色散关系和有限周期光子晶体的透射系数两个方面,对有限和无限周期光子晶体有效折射率的实部和虚部特性曲线分别进行了计算和分析.结果表明一维光子晶体的色散曲线与弹性电偶极子的经典色散曲线类似,在光子晶体的导带为正常色散,而在禁带呈现反常色散.并且用简约布里渊和扩展布里渊区色散曲线对文献报道中存在的两种矛盾的计算结果进行了理论的探讨.解释了导致对一维光子晶体有效折射率计算存在两种不同结果的原因. 相似文献
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得到了全矢量有效折射率方法中归一化等效纤芯半径(p/Λ)随归一化空气孔直径(d/Λ)和归一化频率(Λ/λ)的变化关系,修正了p/Λ为固定值的不合理取法,得到了改进的全矢量有效折射率方法(IFVEIM).用IFVEIM计算的基模有效折射率和总色散等模式特性与多极法的结果和试验值相比较都具有很好的一致性,将基模有效折射率的误差减小了2—3个数量级.用IFVEIM详细地分析了光子晶体光纤的色散特性,得到了色散值、波长、孔间距、d/Λ之间的相互变化关系.
关键词:
光子晶体光纤
有效折射率方法
等效纤芯半径
色散 相似文献
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根据石英晶体的旋光色散特性,利用光学矩阵方法对多级石英晶体旋光光学滤波器的滤波原理进行了详细的理论分析,推导出多级石英晶体旋光光学滤波器的透射主峰波长和通带半宽度的计算公式.利用分光光度计对单级和多级石英晶体旋光光学滤波器的滤波特性进行了实验研究,结果表明单级和多级石英晶体旋光光学滤波器滤波特性与理论曲线一致.从理论和实验上证明了多级石英晶体旋光光学滤波器与单级相比通带半宽度得到了有效的压缩,且随滤波器级数的增大,压缩的程度也随之增大.
关键词:
光学滤波器
偏振
石英晶体
旋光色散 相似文献
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用平面波展开法对光子晶体光纤中电磁场的Maxwell方程组进行了求解。将光纤截面作为超元胞衍生出一个无边界的二维周期性系统,光纤纤芯等效为光子晶体中的缺陷,借助平面波法对其性质进行研究,模拟了半导体中的超格子。运用上述超格子模型,对与纤芯同列孔半径可变的高双折射及与包层中纤芯距离最近的孔半径可变的色散平坦光子晶体光纤的光学性质进行了研究,发现与纤芯同列的孔半径变化时,其双折射比传统光纤更强,而当包层中距离纤芯最近的孔半径取特定值时,可得到近零色散平坦光纤并在大范围内获得反常色散。与传统光纤和普通光子晶体光纤相比,这种新型的色散平坦光纤在密集波分复用(DWDM)光通信系统中具有更高的应用价值。 相似文献
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Designing of a polarization beam splitter for the wavelength of 1310 nm on dual-core photonic crystal fiber with high birefringence and double-zero dispersion
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We have proposed a novel kind of photonic crystal fiber which contains two asymmetric cores. The bireti'ingence and the dispersion are numerically analyzed based on finite element method when the size of the air holes and the pitch of two adjacent air holes are changed. It is shown that the proposed photonic crystal fiber has high birefringence up to the order of 10-2 and double-zero dispersion points are at the wavelengths of 1310 nm and 800 rim, simultaneously. At the same time, the normalized power and the extinction ratios of the proposed photonic crystal fiber have been simulated. It is demonstrated that, at the wavelength of 1310 rim, the x-polarized mode and the y-polarized mode are separated when the propagation distance is 2.481 ram. 相似文献
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Based on a full-vector model, a theoretical study on a kind of high birefringence photonic crystal fibre is presented. Due to introducing air holes of two different sizes into the cladding, twofold rotational symmetry was obtained. We demonstrate the possibility of achieving high birefringence that is at least one order of magnitude higher than that of conventional polarization-maintaining fibres. The dependences of modal birefringence, modal field and differential group delay on the structure parameter of the fibres are discussed in detail. The numerical results are in very good agreement with the experimental results in the literature. 相似文献
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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
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Calculation of geometrical birefringence from two-dimensional refractive-index profile in single-mode fibres
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We present two numerical approaches to calculate the geometrical birefringence from two-dimenslonal refractive-index profile in single-mode fibres. One is the improved perturbation model theory, the other is based on the general solution of noncircular uniform optical waveguide in an arbitrary coordinate system. Using these methods, we can obtain not only the magnitude of geometrical birefringence, but also the orientation of birefrlngent axes. We report the calculation results of geometrical birefringence in a real single-mode fibre. 相似文献
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High birefringence, low loss terahertz photonic crystal fibres with zero dispersion at 0.3 THz
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A terahertz photonic crystal fibre (THz-PCF) is designed for terahertz wave propagation. The dispersion property and model birefringence are studied by employing the finite element method. The simulation result reveals the changing patten of dispersion parameter versus the geometry. The influence of the large frequency band of terahertz on birefringence is also discussed. The design of low loss, high birefringence THz-PCFs with zero dispersion frequency at 0.3 THz is presented. 相似文献
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针对光纤通信和传感系统中高双折射、多零色散点的应用需求, 设计了一种新型结构的光子晶体光纤.该结构包层为圆形空气孔按照八边形形状排列而成, 并在内包层对称位置中加入两个椭圆空气孔以获得高双折射特性. 通过有限元数值分析方法对光纤特性进行分析,仿真结果表明,该结构光子晶体光纤在波长0.8—2 μm 范围内双折射可达10-3量级,满足高双折射的应用需求,并且满足两个零色散点的应用需求. 同时光纤的非线性系数达10-2·m-1·W-1量级,可应用于对非线性要求较高的场合. 相似文献
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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
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We present a simple method for measuring the wavelength dependence of both the phase and group birefringences in a quartz crystal of known thickness. The method utilizes interference of polarized waves resolved by a fiber-optic spectrometer as a channeled spectrum (spectral fringes). The fringe order versus the precise position of the interference maximum in the spectrum is fitted to the approximate function, from which the phase birefringence as a function of wavelength is retrieved. We also determine the group birefringence dispersion. The functions measured in a range from 500 to 900 nm are compared with those resulting from the available dispersion relation, and very good agreement is confirmed. 相似文献