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1.
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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《光电子快报》2008,4(3)
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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A highly birefringent index-guiding photonic crystal fiber (PCF) with flattened dispersion and low confinement loss is proposed by introducing two small air holes with the same diameter in the core area. The fundamental mode field, birefringence, confinement loss, effective mode area and dispersion characteristic of the fibers are studied by the full-vector finite element method (FEM). Simulation results show that a high birefringence with the order of 10 -3 and a low confinement loss of 0.001 dB/km are obtained at 1550 nm. Furthermore, flattened chromatic dispersion from 1450 nm to 1590 nm is obtained. 相似文献
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设计了一种基于双折射效应的新型矩形纤芯光子晶体光纤偏振分束器,通过在矩形晶格结构的光子晶体光纤的每个纤芯中引入一对椭圆来增加结构的双折射。应用全矢量有限元法(FEM)分析了双芯光子晶体光纤中结构参数对双折射和耦合长度特性的影响,数值模拟了该偏振分束器的性能。结果表明:增大椭圆率可以在增大结构的双折射的同时减小耦合长度,并且该分束器在工作波长为1.55 m、传输长度为282 m 的光纤中能够实现偏振状态的隔离,消光比达到最小值-45.42 dB,并且在1.507~1.596 m、带宽为89 nm 的范围内消光比小于-10 dB。 相似文献
5.
Using an adaptive split-step Fourier method,the coupled nonlinear Schrdinger equations have been numerically solved in this paper.The nonlinear propagation of an ultrashort optical pulse in the birefringent photonic crystal fibers is investigated numerically.It is found that the phenomenon of pulse trapping occurs when the incident pulse is deviating from the principal axis of the fiber with some angle.Owing to the birefringence effect,the incident pulse can be regarded as two orthogonal polarized pulses.The phenomenon of pulse trapping occurs because of the cross phase modulation(XPM) between the two components.As a result,the bandwidth of the supercontinuum(SC) decreases compared with the case that the incident pulse is input along the principal axis.When the polarization direction of the incident pulse is parallel to the fast axis,the bandwidth of the supercontinuum is maximal. 相似文献
6.
《Optical Fiber Technology》2014,20(1):32-38
This paper presents an optimum design for highly birefringent hybrid photonic crystal fiber (HyPCF) based on a modified structure for broadband compensation covering the S, C, and L-communication bands i.e. wavelength ranging from 1460 to 1625 nm. The finite element method (FEM) with perfectly matched layer (PML) circular boundary is used to investigate the guiding property. It is demonstrated that it is possible to obtain broadband large negative dispersion, and dispersion coefficient varies from −388.72 to −723.1 ps nm−1 km−1 over S, C and L-bands with relative dispersion slope (RDS) matched to that of single mode fiber (SMF) of about 0.0036 nm−1 at 1550 nm. According to simulation, a five-ring dispersion compensating hybrid cladding photonic crystal fiber (DC-HyPCF) is designed that simultaneously offers birefringence of order 3.79 × 10−2, nonlinear coefficient of 40.1 W−1 km−1 at 1550 nm wavelength. In addition to this, effective area, residual dispersion, and confinement loss of the proposed DC-HyPCF are also reported and discussed. 相似文献
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Properties of a highly birefringent photonic crystal fiber 总被引:8,自引:0,他引:8
J. Ju W. Jin M.S. Demokan 《Photonics Technology Letters, IEEE》2003,15(10):1375-1377
We report the results of our recent investigation on the properties of a highly birefringent photonic crystal fiber including modal birefringence, mode field diameter, divergence angle, and polarization mode dispersion, which are important for sensing and communication applications. 相似文献
10.
Single-polarization single-mode photonic crystal fibers 总被引:5,自引:0,他引:5
K. Saitoh M. Koshiba 《Photonics Technology Letters, IEEE》2003,15(10):1384-1386
A new structure of single-polarization single-mode (SPSM) photonic crystal fiber (PCF) is proposed and analyzed by using a full-vector finite element method with anisotropic perfectly matched layers. From the numerical results it is confirmed that the proposed fiber is low-loss SPSM-PCF within the wavelengths ranging from 1.48 to 1.6 /spl mu/m, where only the slow-axis mode exists and the confinement loss is less than 0.1 dB/km. 相似文献
11.
A large-solid-core fiber design comprised by omitting nine air-holes at the center of square-lattice photonic crystal is investigated for the constant air-hole diameter and for the constant pitch length of air-holes. The fiber characteristics are calculated for both structures, and the results are compared. In the calculations, the plane-wave expansion method is used for effective indices, and we utilized the step-index fiber and Gaussian mode profile approximations for obtaining the effective V-number and the effective mode area respectively. 相似文献
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光子晶体光纤的传输性能 总被引:1,自引:0,他引:1
文章首先提出了石英玻璃单模光纤在高速率、大容量和远距离光纤通信中应用时存在的问题,然后在介绍光子晶体光纤的结构特点、导光机理的基础上,简要地阐述了光子晶体光纤的研究历史和最新研究成果;最后综述了光子晶体光纤的衰减、色散和非线性效应等传输性能. 相似文献
14.
Numerical modeling of photonic crystal fibers 总被引:10,自引:0,他引:10
Recent progress on numerical modeling methods for photonic crystal fibers (PCFs) such as the effective index approach, basis-function expansion approach, and numerical approach is described. An index-guiding PCF with an array of air holes surrounding the silica core region has special characteristics compared with conventional single-mode fibers (SMFs). Using a full modal vector model, the fundamental characteristics of PCFs such as cutoff wavelength, confinement loss, modal birefringence, and chromatic dispersion are numerically investigated. 相似文献
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Numerical aperture of single-mode photonic crystal fibers 总被引:1,自引:0,他引:1
Mortensen N.A. Folken J.R. Skovgaard P.M.W. Broeng J. 《Photonics Technology Letters, IEEE》2002,14(8):1094-1096
We consider the problem of radiation into free space from the end-facet of a single-mode photonic crystal fiber (PCF). We calculate the numerical aperture NA = sin /spl theta/ from the half-divergence angle /spl theta/ /spl sim/ tan/sup -1/ (/spl lambda///spl pi//spl omega/) with /spl pi//spl omega//sup 2/ being the effective area of the mode in the PCF. For the fiber first presented by Knight et al. (1996), we find a NA /spl sim/ 0.07 which compares to standard fiber technology. We also study the effect of different hole sizes and demonstrate that the PCF technology provides a large freedom for NA engineering. Comparing to experiments we find good agreement. 相似文献
17.
Lin Zhang Changxi Yang 《Lightwave Technology, Journal of》2004,22(5):1367-1373
The polarization dependence of light coupling in photonic crystal fibers (PCFs) with sixfold symmetric dual cores and highly birefringent dual cores are numerically investigated. The characteristics of PCF-based couplers, such as coupling length, extinction ratio and form birefringence, are examined as functions of the air-hole size and pitch. The silica bridges between air holes take an important role in the energy transfer across the two cores. We believe that the mechanism of light coupling in PCF-based couplers is different from that of conventional waveguide couplers. The polarization dependent coupling can be reduced by adjusting the air holes around the cores of PCFs. On the other hand, the polarization dependent coupling can be enhanced by introducing high birefringence in the two cores. 相似文献
18.
《Optical Fiber Technology》2013,19(5):461-467
In this paper, we propose and demonstrate a highly birefringent photonic crystal fiber based on a modified octagonal structure for broadband dispersion compensation covering the S, C, and L-communication bands i.e. wavelength ranging from 1460 to 1625 nm. It is shown theoretically that it is possible to obtain negative dispersion coefficient of about −400 to −725 ps/(nm km) over S and L-bands and a relative dispersion slope (RDS) close to that of single mode fiber (SMF) of about 0.0036 nm−1. According to simulation, birefringence of the order 1.81 × 10−2 is obtained at 1.55 μm wavelength. Moreover, effective area, residual dispersion, effective dispersion, confinement loss, and nonlinear coefficient of the proposed modified octagonal photonic crystal fiber (M-OPCF) are also reported and discussed. 相似文献
19.
The hollow-core photonic crystal fibers (HC-PCFs) with integrity structure have been fabricated with an improved twice stack-and-draw technique. The transmission spectrum shows that five photonic band-gaps within 450-1100 nm have been obtained.And the green fight transmission in the HC-PCFs has been observed remarkably. 相似文献
20.
《光电子快报》2008,4(4)
The hollow-core photonic crystal fibers(HC-PCFs) with integrity structure have been fabricated with an improved twice stack-and-draw technique.The transmission spectrum shows that five photonic band-gaps within 450-1100 nm have been obtained.And the green light transmission in the HC-PCFs has been observed remarkably. 相似文献