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利用矢量有效折射率方法(矢量法)对光子晶体光纤基模的色散特性进行了数值模拟,并与双正交归一基矢量法以及标量有效折射率方法(标量法)的模拟结果进行了对比.发现所用矢量法的结果与双正交归一基矢量法的结果符合很好,而标量法在低空气填充率f或较高归一化波数A/λ时是一种较好的近似,在空气填充率f较高或归一化波数A/λ较低时,要得到精确的结果必须利用矢量法对光子晶体光纤的特性进行模拟.讨论了光子晶体光纤包层有效折射率与光纤结构的关系.
关键词:
光子晶体光纤
矢量法
有效折射率
色散 相似文献
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We report the excitation by flexural acoustic waves of an individual cladding mode in a single-mode photonic crystal fiber. The propagation constant and the field distributions of the mode have been investigated by use of this technique. The results give the basis for developing a family of acousto-optic devices based on photonic crystal fibers. 相似文献
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In this paper, we present and explore a new hybrid cladding design for improved birefringence and highly nonlinear photonic crystal fibers (PCFs) in a broad range of wavelength bands. The birefringence of the fundamental mode in such a PCF is numerically analyzed using the finite element method (FEM). It is demonstrated that it is possible to design a simple highly nonlinear hybrid PCF (HyPCF) with a nonlinear coefficient of the about 46 W−1 km−1 at a 1.55 μm wavelength. According to simulation, the highest modal birefringence and lowest confinement loss of our proposed structure at the excitation wavelength of λ = 1.55 μm can be achieved at a magnitude of 1.77 × 10−2 and of the order less than 102 dB/km with only five rings of air-holes in the fiber cladding. 相似文献
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We extend the improved effective index method (IEIM) to analyze the cladding mode of the photonic crystal fiber (PCF) and to predict cladding mode coupling in gratings. By introducing a new step-index fiber model for the PCF, the cladding mode coupling between a LP01 core mode and HE11 cladding mode in long-period gratings formed in PCF is accurately predicted by the IEIM. The fiber model works well for the PCF used here not only in predicting resonant mode coupling, but also in analyzing core and low-order cladding modes. 相似文献
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We propose and demonstrate hydrophobic photonic crystal fibers (PCFs). A chemical surface treatment for making PCFs hydrophobic is introduced. This repels water from the holes of PCFs, so that their optical properties remain unchanged even when they are immersed in water. The combination of a hollow core and a water-repellent inner surface of the hydrophobic PCF provides an ultracompact dissolved-gas sensor element, which is demonstrated for the sensing of dissolved ammonia gas. 相似文献
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Elliptical-hole photonic crystal fibers 总被引:9,自引:0,他引:9
We study the dispersive properties of photonic crystal fibers (PCF's) with elliptical air holes. The unusual guidance of PCF leads to novel behavior of the birefringence, group-velocity walk-off, and dispersion parameters, including the possibility of zero walk-off with high birefringence in the single-mode regime. A number of these effects are closely tied to the underlying radiation states of the air-hole lattice. 相似文献
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In multimode bandgap guiding fibers higher-order modes have high radiation losses. Once excited, after a short propagation distance such modes are leaked out of the fiber core. Reduction of the number of excited modes in the fiber core leads to a decrease of intermodal dispersion and a dramatic enhancement of fiber bandwidth. Due to the increase in the propagation loss, bandwidth enhancement by differential mode attenuation also leads to the reduction of the maximal length of a usable fiber span. We demonstrate that by proper design of a photonic crystal reflector long fiber spans of high bandwidth are possible. 相似文献
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We experimentally investigate the spectral characteristics of side-polished endlessly single-mode photonic crystal fibers of different polishing depths and radii of curvature that are important to mode field diameter, evanescent coupling, waveguide losses, higher-order mode excitation, and dispersion slopes of photonic crystal fiber components. A polished photonic crystal fiber with a greater polishing depth or a larger radius of curvature shows a more dispersive characteristic. In contrast to conventional single-mode fibers, in photonic crystal fibers the evanescent field is more strongly localized, and the propagating light can be more efficiently guided within the deformed core. 相似文献
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Sun Gui-Lin Chen Zi-Lun Xi Xiao-Ming Hou Jing Jiang Zong-Fu 《Optics Communications》2012,285(6):1331-1334
The general principles for designing mode converters based on air-hole collapse in photonic crystal fibers (PCFs) are theoretically investigated in this paper. The splice-like point in mode converters is found unnecessary for mode conversion; however, two different and separated cores, the adiabatic transitional part and the final merged core, are essential. Three structures are investigated using logical deduction, and the numerical results agree well with the logical conclusions. 相似文献
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Group-velocity dispersion in photonic crystal fibers 总被引:12,自引:0,他引:12
The dispersion properties of photonic crystal fibers are calculated by expression of the modal field as a sum of localized orthogonal functions. Even simple designs of these fibers can yield zero dispersion at wavelengths shorter than 1.27 mum when the fibers are single mode, or a large normal dispersion that is suitable for dispersion compensation at 1.55 mum. 相似文献
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All-solid silica-based photonic crystal fibers 总被引:1,自引:0,他引:1
Ming-Yang Chen 《Optics Communications》2006,266(1):151-158
An index-guiding all-solid photonic crystal fiber (PCF) composed entirely of silica material is proposed in this paper. The core of this optical fiber is composed of pure silica, and the cladding consists of doped silica rod in the background of pure silica. The dependence of confinement loss on the diameter of the doped rods, the number of doped-rod rings, and the doping level is investigated numerically. In addition, the proposed fiber possesses a shorter cutoff wavelength as compared with the air/silica PCF, which is directly confirmed by the V parameter, and explained based on a scalar approximation method. Furthermore, the bending loss for the fiber is predicted. A low-loss single-mode all-solid silica-based PCF with a large-mode-area is possible by the appropriate selection of configuration parameters. 相似文献
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Highly birefringent photonic crystal fibers 总被引:46,自引:0,他引:46
Ortigosa-Blanch A Knight JC Wadsworth WJ Arriaga J Mangan BJ Birks TA Russell PS 《Optics letters》2000,25(18):1325-1327
We report a strongly anisotropic photonic crystal fiber. Twofold rotational symmetry was introduced into a single-mode fiber structure by creation of a regular array of airholes of two sizes disposed about a pure-silica core. Based on spectral measurements of the polarization mode beating, we estimate that the fiber has a beat length of approximately 0.4 mm at a wavelength of 1540 nm, in good agreement with the results of modeling. 相似文献
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We propose a novel air-guiding photonic bandgap fiber based on a square lattice cladding. The fiber presents a 20% wider bandgap than is achievable with a conventional triangular-lattice-based cladding and with the choice of a nine-cell core can be effectively single moded at all wavelengths within the bandgap. 相似文献
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《中国光学快报(英文版)》2017,(6)
Through doping liquid crystals into the core region, we propose a kind of seven-core photonic crystal fiber(PCF)which can achieve mode shaping and temperature sensing simultaneously in the communication window of1.1–1.7 μm. To the best of our knowledge, this is the first time that the function of seven-core PCFs as temperature sensors is investigated. By using the full vectorial finite element method, the characteristics of the fiber with the temperature, such as the effective mode area, the waveguide dispersion, and the confinement loss, are analyzed. This kind of PCF can be competitive in providing temperature sensing in multi-core PCF lasers. 相似文献
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Analytical solution of the fundamental space filling mode of photonic crystal fibers 总被引:1,自引:0,他引:1
Yan-feng Li Ching-yue Wang Zi-han Wang Ming-lie Hu Lu Chai 《Optics & Laser Technology》2007,39(2):322-326
Analytical solution of the fundamental space filling mode of photonic crystal fibers is revisited based on previous results by Midrio et al. [J Lightwave Technol 2000;18(7):1031–7]. The fundamental space filling mode is designated HE11 mode following the conventional mode classification. A comparison is made between the vectorial method and the scalar method when identical parameters are used in the analytical solution. A more accurate radius of the equivalent circular unit cell is determined. 相似文献
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Juan Juan Hu Ping Shum Xia Yu Chao Lu Tomasz R. Wolinski 《Optics Communications》2008,281(17):4339-4342
We have analyzed the thermal influence on the bandgap properties of liquid-crystal photonic crystal fibers. The bandgap parameters which affect the transmission conditions have been investigated. It is observed that the photonic bandgap can be thermally tuned, i.e. the red or blue shift of the bandgap results from the temperature dependence of the refractive index of the liquid crystal. For the planar alignment of liquid-crystal filled cladding, the ordinary refractive index plays a major role in determining the bandgap properties; the extraordinary refractive index comes into influence while the ordinary refractive index is relatively constant of temperature. The analyses agree well with the experiments results. 相似文献