八边形低色散高非线性光子晶体光纤的设计

为了得到平坦色散高非线性的光子晶体光纤,设计了一种用于新颖的八边形三包层光子晶体光纤结构,采用多极法研究了空气孔直径、孔间距对色散和非线性的影响。结果表明,色散值和非线性系数随着内层空气孔直径d1的增大整体逐渐减小;随着第3圈空气孔直径d3的逐渐增大,色散值逐渐增大,但非线性基本保持不变;第2圈及外圈空气孔直径的变化对色散及非线性的影响较小。通过合理调节结构参量,在1.46μm～1.73μm近270nm波段内,色散绝对值在0.5ps/(km·nm)范围内波动;在1.5μm～1.65μm近150nm范围内的非线性系数值介于42.5W-1·km-1～50W-1·km-1。这一结果对设计特定功能的光子晶体光纤提供了理论参考。     

八边形光子晶体光纤色散及非线性的研究

设计了一种多包层正八边形结构光子晶体光纤,研究了空气孔直径、孔间距对色散及非线性的影响;通过优化结构参量,理论上实现了在1.47~1.6μm波长范围色散值在±0.2ps/(km·nm)之间波动;在波长1.55μm处非线性系数值高达40.5(1/W·km)。获得了在1550nm附近具有平坦色散和高非线性双零色散光子晶体光纤,为研究非线性效应提供了一定的理论基础。     

平坦色散高非线性光子晶体光纤的制备与实验

运用改进的全矢量有效折射率法(IFVEIM),课题组自行设计了一种在900 nm附近具有低平坦色散高非线性特性的光子晶体光纤.并且在改进工艺的基础上,采用中心抽真空挤压法对其进行了制备.虽然所制得光纤的结构参数与理论设计值存在一定的偏差,但其在所研究波段内色散值仅为0.5 ps/km/nm,非线性系数值则达到了35(W*km)-1,这在当前规则结构的纯硅光子晶体光纤中已经很高.最后,我们对其进行了非线性实验测试,其在400～1 400 nm的波段范围内展现出了宽平坦的超连续谱.     

高双折射低色散光子晶体光纤设计

为了高效传输太赫兹(Terahertz,THz)波并促进太赫兹的实际应用.提出了一种具有高双折射,低色散特性的太赫兹光子晶体光纤(Photonic Crystal Fiber,PCF).利用全矢量有限元法对所提出的PCF 结构进行数值仿真,分析了结构参数与双折射以及色散的关系.仿真结果表明,该光纤在0.9～1.3 TH...     

Proposal for highly birefringent broadband dispersion compensating octagonal photonic crystal fiber

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.     

高非线性色散平坦光子晶体光纤的理论研究

为了研究光子晶体光纤结构参数对非线性系数及色散特性的影响,采用全矢量等效折射率模型,进行了理论分析,研究发现,通过调节结构参数可以灵活设计波长在820nm附近具有较大非线性系数和较低色散值的高非线性色散平坦光子晶体光纤。结果表明,高非线性色散平坦光子晶体光纤的研究前景十分可观。     

八角晶格光子晶体光纤的损耗特性分析

应用多极法对O-PCF的损耗进行了计算和分析,并与H-PCF进行了比较,发现相同空气填充率下,O-PCF的损耗小于H-PCF的损耗,O-PCF在能获得更大有效模式面积的同时,在损耗特性方面也更具优势;研究了包层空气孔层数、孔直径和孔间距等在1.33 μm和1.55μm处对损耗的影响,得到了损耗随各结构参数变化的规律,并总结了获得低损耗大模面积O-PCF的一般方法.     

高双折射高非线性低损耗八边形光子晶体光纤特性

为了同时实现高双折射高非线性并得到低损耗,设计一种在光纤纤芯附近引入椭圆形空气孔和圆形空气孔组成的新型优化的八边形光子晶体光纤。采用全矢量有限元法结合各向异性完美匹配层,对该光纤的有效面积、非线性、双折射和损耗特性进行了模拟分析。数值模拟结果表明,通过选择适当的结构参数,在波长1.55 m处,该光纤具有高双折射高达B=1.6810-2,比普通光纤高两个数量级,高非线性系数为=60 W-1km-1和低损为0.6 dB/km。这种具有高双折射高非线性系数的光纤可用于光通信、偏振敏感的各种设备和产生超连续普等领域。     

A novel polarization splitter based on octagonal dual-core photonic crystal fiber

A novel polarization splitter based on octagonal dual-core photonic crystal fiber(O-D-PCF) is proposed. The impacts of several fiber parameters on the coupling characteristics of the polarization splitter are investigated by full-vectorial finite element method(FV-FEM) in detail. Through optimizing the fiber configuration, a 4.267-mm-long polarization splitter with a bandwidth of 37 nm is achieved, and its extinction ratio(ER) is as high as 81.2 d B at the wavelength of 1.55 μm. Compared with the hexagonal dual-core photonic crystal fiber(H-D-PCF) based polarization splitter, both ER and bandwidth of the O-D-PCF based one are effectively improved.     

A novel highly negative dispersion photonic crystal fiber

Based on the full-vector finite element method,a novel structure of highly negative dispersion photonic crystal fiber with the central index dip in the low germanium doped core is proposed.The highly negative dispersion can be obtained at the wavelength of 1.55 μm by adjusting the pitch,the air-hole diameter in the third ring,the germanium doped concentration and the influence of central index dip.     

新型光子晶体光纤近零平坦色散的研究

文章作者设计了一种新型的光子晶体光纤(PCF),在纤芯引入了一个小空气孔形成缺陷,并改变第一层空气孔的直径.采用平面波法研究了该PCF的色散特性,结果表明,该光纤能够得到比传统的PCF更低、更平坦的色散曲线;通过优化该光纤的结构参数,可以设计在1 350～2 010 nm波长范围内近于零的平坦色散PCF,其色散变化△D＜0.5 ps/(km·nm),在1 320～2 040 nm波长范围内色散斜率变化△D<,slope>＜0.02 ps/(km·nm<'2>).     

近零平坦色散三包层光子晶体光纤的设计

为了使光子晶体光纤（PCF）在钛宝石飞秒激光器的工作波长0.80 m 和光通信窗口1.55 m 处获得宽的近零超平坦色散,使用了三包层六角空气孔环结构设计来代替普通的单包层结构。应用了改进的有效折射率法对该三包层PCF 进行了数值模拟。结果表明:三包层PCF 的色散随结构参数的微小变化而有较大的变化,因此通过对PCF 结构参数的合理调节,分别实现了在0.800.02 m 和1.550.15 m 波长范围内近零、平坦色散（色散范围0.5 ps/（kmnm）,色散斜率范围0.02 ps/（kmnm2）的结构设计。这对于光通信系统及研究飞秒激光在PCF 中的传输特性,拓展飞秒激光的研究和应用都具有重要意义。     

Design for photonic crystal fibers with high nonlinearity and flattened dispersion for self-frequency shift of Raman soliton

A new concept of photonic crystal fiber (PCF) with high nonlinearity and flattened dispersion was designed. The PCF structure is indeed a hexagon lattice. The bigger air holes in the outer rings are used to confine the light field into the core region for enhancing the nonlinearity. The flattened dispersion can be achieved by adjusting the diameters of six smaller air holes in the first ring, and six micro air holes are inserted between smaller air holes for higher nonlinearity and the better flattened dispersion. By optimizing the size of the smaller and micro holes, the PCF can reach to high nonlinearity of 23.3 W⁻¹ · km⁻¹ and the low dispersion of 51.32 ps/(nm·km) with the fluctuation range of 0.98 ps/(nm·km), which is within the wavelength range of 1 400 nm to 1 900 nm. The designed PCF can be used in important applications in realizing the Raman soliton self-frequency shift (RSSFS).     

高非线性平坦色散光子晶体光纤的研究

为了研究最内层空气孔的大小以及空气孔的占空比改变对光子晶体光纤的非线性系数、色散的影响,采用全矢量有限元方法,进行了理论分析和实验验证,取得了非线性系数、色散系数随频率和结构参量的变化数据。结果表明,三角晶格结构的非线性系数大,色散较平坦,能够在400nm~1160nm保持单模传输,非线性系数达到172km-1·W-1,在0.65μm~1.0μm范围内具有超平坦色散。这一结果对光通信领域的研究是有帮助的。     

平坦色散低限制损耗光子晶体光纤的设计

为了得到一种新的具有低限制损耗和平坦色散的光子晶体光纤,设计了具有6层空气孔的正八边形结构,将包层分布为3种不同空气孔直径d1,d2,d3,采用多极法数值模拟了这些结构参量对其色散特性和限制损耗的影响.得列在1.3μm～1.72μm波长范围内,光纤的色散系数介于-0.1ps/(km·nm)～0.58ps/(km·nm)...     

高双折射光子晶体光纤设计及分析

为进一步提高光纤传输特性,设计了两种具有高双折射的新型光子晶体光纤, 构建了光纤的模型。通过有限元法对光纤模型进行数值计算并研究了光纤结构参数对基模色 散、双折射、限制性损耗、非线性系数等传输特性的影响。研究表明,在波长为1550 nm处, 本文所设计的两种光纤分别可获得高达3.676×10－2和4.477×10－2的双折射,两种光 纤的限制 性损耗都保持在10－8 dB/m数量级及以下,且都具有较低的非 线性系数。因此,光纤传输性 能的优化使得其更有利于光信号的长距离稳定传输,可应用于高速光通信、光纤传感、色散 补偿等领域。     

新型六角芯光子晶体光纤的色散补偿特性研究

文章利用多极法对新型六角芯光子晶体光纤的色散特性进行了数值模拟与分析,研究发现,通过改变第一包层空气孔直径和空气孔间距,可以灵活地设计波长在1.55μm附近具有高色散值、大的负色散斜率和能在短波长内单模传输的色散补偿型光纤.数值模拟和分析表明,该光子晶体光纤在色散补偿型光纤方面具有广泛的应用前景.     

A novel multi-waveband dispersion compensating fiber based on hybrid photonic crystal fiber

In view of dispersion compensating in multiple wavebands at the same time, this paper proposes a novel multi-waveband dispersion compensating fiber (DCF) based on hybrid photonic crystal fiber (PCF). The proposed fiber can compensate multiple wavebands at the same time. The mechanism of the multi-waveband dispersion compensation is analyzed, and the different material-filled structure is discussed numerically. The simulation results show that the multi-waveband DCF can compensate multiple wavelengths at the same time. By a reasonable design, this fiber can replace the multi-dispersion compensating system composed by cascaded multiple devices, and minimize the loads of the system in an efficient way.     

Anomalous dispersion in photonic crystal fiber

We describe the measured group-velocity dispersion characteristics of several air-silica photonic crystal fibers with anomalous group-velocity dispersion at visible and near-infrared wavelengths. The values measured over a broad spectral range are compared to those predicted for an isolated strand of silica surrounded by air. We demonstrate a strictly single-mode fiber which has zero dispersion at a wavelength of 700 mm. These fibers are significant for the generation of solitons and supercontinua using ultrashort pulse sources     

零模间色散三芯光子晶体光纤

为了研究纤芯掺杂低折射率材料后三芯光子晶体光纤中任意两超模之间的模间色散特性,采用全矢量有限元法进行了仿真,取得了模间色散系数、零模间色散波长随纤芯折射率和结构参量变化的数据。结果表明,通过调节纤芯折射率、纤芯直径、空气孔直径以及孔间距这4个结构参量,可以使任意两超模间的模间色散在两个常用波段1.31m和1.55m处为0。该结果对于消除基于模分复用的光纤不同模式间因为模间色散导致的脉冲失真和实现零模间色散的模分复用技术是有帮助的。