带隙型光子晶体光纤的研究进展

阐述了带隙型光子晶体光纤(PBG-PCF)的发展历史、导光机制和三角形结构光子带隙光纤的特点;较全面地讨论了带隙型光子晶体光纤的特性;重点讨论了现有带隙型光子晶体光纤损耗较大的原因及进一步减小损耗的方法.     

新型抗弯曲单模光子晶体光纤的研究

文章提出了一种对称结构的新型抗弯曲单模光子晶体光纤,采用全矢量有限元法分析了该光纤的单模特性及弯曲特性。在1 550nm波长处,光纤处于单模运转;当弯曲半径为5mm时,弯曲损耗仅为8.73×10-5 dB/圈;最小弯曲半径可达4.5mm,此时弯曲损耗为2.38×10-4 dB/圈;且无论光纤弯曲与否,其在1 550nm波长处的模场面积均约为61μm2,色散系数约为11.13ps/(nm·km),与普通单模光纤相匹配。     

新型低弯曲损耗光子晶体光纤的研究

提出了一种新型掺锗芯低弯曲损耗光子晶体光纤。通过调整结构参数,实现了单模低弯曲损耗传输,与标准单模光纤有较好的适配性。仿真结果表明,波长1550nm处,弯曲半径为5mm时,基模损耗为0.014dB/km;弯曲半径为4mm时,基模损耗为0.42dB/km,能承受的弯曲半径小。显示了光子晶体光纤具有成为光纤到户"最后一公里"主要通信介质的性能优势。     

实心光子带隙限制光纤泄漏损耗的研究

芯区向下掺杂的实心蜂窝形光子晶体光纤可以通过光子带隙限制(PBG)导光,本文采用多极方法研究了这种实心PBG光子晶体光纤的泄漏损耗,研究表明在气孔直径与气孔周期的比为0.8时,仅需84个气孔,就能使这种实心PBG光子晶体光纤的泄漏损耗降低到10^-2dB/km.本文的模拟结果可用于实心PBG光子晶体光纤的实际应用.     

HC-PCF的传输特性及其应用

简要介绍了光子晶体的原理,由此引出光子带隙型光子晶体光纤的概念、结构、导光机理及其制备,着重分析空气导光型光子晶体光纤的传输特性,并用时域有限差分(FDTD)法仿真了三角形结构空气导光型光子晶体的色散特性,最后展望其应用前景.     

低损耗近零超平坦色散光子晶体光纤的设计

设计了一种用于买现低损耗、近零超平坦色散特性的光子晶体光纤结构,这种结构光纤包层空气孔层数少,内三层空气孔直径相同,制作过程简单;应用多极法研究了此结构PCF各个参数特别是最外层空气孔直径对色散和损耗特性的影响,通过优化结构,设计出了在1.3μm至1.65μm波长范围内色散绝对值小于0.5ps/（nm.km）,1.55μm处损耗为4.5dB/km的低损耗近零超平坦色散光子晶体光纤。     

一种双包层低损耗色散平坦光子晶体光纤

借助多极法对具有双包层、双孔间距结构光子晶体光纤的色散特性,限制损耗,模场面积进行数值模拟,研究调整内外包层参数对色散和损耗的影响.通过优化结构参数,设计了可以在1.29～1.82μm的波长范围内实现±0.5ps/(km·nm)低色散值的色散平坦光子晶体光纤,其在λ=1.55μm处,限制损耗为2.2×10-3dB/km...     

光子晶体光纤宏弯曲损耗特性的理论分析

利用有效折射率模型对全内反射型光子晶体光纤的宏弯曲损耗特性进行了理论研究,分析了光子晶体光纤的结构参量和弯曲半径对其宏弯曲损耗谱的影响,计算了某些结构参量的光子晶体光纤在1.5 5μm波长处的临界弯曲半径.研究表明,光子晶体光纤的弯曲损耗特性与其结构参量密切相关.     

高双折射光子晶体光纤及其特性研究

提出了一种复合结构的光子晶体光纤,采用多极法对其双折射、限制损耗、基模模场以及色散特性进行了数值模拟.研究表明,该光纤在1 550 nm处可获得1.56×10-2的双折射,限制损耗为7.31×10-3 dB/km,负色散达-320 ps/(nm·km),且损耗在1 300～1 600 nm范围内基本稳定.     

光子带隙型光子晶体光纤研究与应用

带隙型光子晶体光纤(PBG-PCF)因其独特的性能,在各个领域都有着广泛的应用前景.文章阐述了带隙型光子晶体光纤的导光机制,并将带隙型光子晶体光纤分为空芯光子晶体光纤和全固态带隙型光子晶体光纤两类,较全面地讨论了这两类光纤的特性及其应用.     

Dispersion-flattened Bragg photonic crystal fiber for large capacity optical communication system

A novelty dispersion ultra-flattened Bragg photonic crystal fiber (PCF) has been fabricated in this paper.The fiber is composed of compound cores and periodical claddings with 11 coaxial rings.It has flattened dispersion of 8.54±1.3 ps-(nm· km)-1 in the communication wavelength range of 1460-1625 nm.Its dispersion slope alters from -0.0428 to 0.0392ps·nm-2·km-1.The low attenuation of 0.52 dB/km and low bending loss of 0.09 dB at 1550 nm of the fiber are also achieved.The Bragg PCF has enormously potential application in the fields of dense wavelength division multiplexing systems because of its superior dispersion properties and easy splicing performances.     

Photonic crystal fiber with novel dispersion properties

Our recent research on designing microstruc-tured fiber with novel dispersion properties is reported in this paper. Two kinds ofphotonic crystal fibers (PCFs) are introduced first. One is the highly nonlinear PCF with broadband nearly zero flatten dispersion. With introducing the germanium-doped (Ge-doped) core into highly non-linear PCF and optimizing the diameters of the first two inner rings of air holes, a new structure of highly non-linear PCF was designed with the nonlinear coefficient up to 47 W-1·km-1 at the wavelength 1.55 μm and nearly zero flattened dispersion of ±0.5 ps/(km·nm) in telecom-munication window (1460-1625nm). Another is the highly negative PCF with a ring of fluorin-doped (F-doped) rods to form its outer ring core while pure silica rods to form its inner core. The peak dispersion - 1064 ps/(km·nm) in 8 nm full width at half maximum (FWHM) wavelength range and -365ps/(km·nm) in 20nm (FWHM) wavelength range can be reached by adjusting the structure parameters. Then, our recent research on the fabrication of PCFs is reported. Effects of draw parameters such as drawing temperature, feed speed, and furnace temperature on the geometry of the final photonic crystal fiber are investigated.     

低折射率芯PCF基模损耗的数值模拟与分析

应用多极法理论计算了低折射率芯光子晶体光纤（PCF）基模的损耗并与未掺杂芯PCF进行了比较，发现可以从损耗的角度来理解低折射率芯PCF的截止特性：传输波长靠近短波长时，模式的损耗会突然变大，从而导致基模截止；而处于长波长时，这种光纤的传输特性和普通PCF相类似。通过改变纤芯折射率的大小和包层中空气孔的大小，可以对光纤的截止波长进行调节。     

全固高非线性低色散斜率光子晶体光纤设计

提出了利用掺氟同心圆环的光纤结构来提高光子晶体光纤(PCF)的非线性,所需控制的参量仅有两个。设计了三种具有高非线性、低色散斜率和低限制损耗的全固光子晶体光纤。这三种光纤分别具有正常色散、双零色散点和零色散点恰好在1.55 μm波长处的色散曲线特性。所设计的零色散点恰好在1.55 μm波长处的光子晶体光纤色散斜率值为5.12×10-4 ps/(km·nm2),这比传统的高非线性光纤的色散斜率小了2个数量级。同时,该光纤在1.55 μm波长处的非线性系数为31.5 W-1·km-1,限制损耗为9.62×10-5 dB/km。     

Analysis of modal characteristics and thermal effects on photonic crystal fiber laser

In this paper, thermo-optics effects on fiber lasers based on index-guiding photonic crystal fibers (PCFs) are studied. The modal characteristics of the PCF lasers are discussed in terms of the thermal effects. Modal analysis of PCF has been done with help of plane wave expansion and supercell lattice methods. The thermal analysis is performed by obtaining the effective index of fundamental mode and core confinement factor (CCF) when the fiber laser was pumped. The results show that PCF laser structure has negligible modal sensitivity to thermal load in comparison to conventional fiber laser. Analyzing the mode performance of the fiber laser under thermal load shows that the assumed PCF laser at 80 W/m pump power show ∼500° rise in temperature and 0.34% propagation constant variation in fundamental mode index and 0.04% CCF variation in fundamental mode.     

基于FDTD方法的光子晶体光纤色散特性分析

基于电磁场时域有限差分法(FDTD)计算光子晶体光纤(PCF)的方法, 分析了运用该方法时需要注意的一些问题, 特别是关于晶格位置、晶格上各个电磁场分量的分布以及完全匹配层(PML)中在边界处的电磁场的处理。以此为理论依据分析了一种纯石英材料双层芯PCF, 对这种光纤的传输特性进行了详细的数值模拟。通过调整光纤的结构参数, 设计出大负色散值的宽带色散补偿光子晶体光纤(DCPCF)。数值模拟结果显示在1530～1565 nm波长范围内其色散值在-400和-600 ps/(km·nm)之间变化, 达到了具有相同有效模面积的普通色散补偿光纤(DCF)的5倍。在整个C波段可以有效补偿长度25倍以上的标准单模光纤(SMF), 其色散剩余量在±1.0 ps/nm·km以内。该种结构的PCF对于制作高增益和宽带色散补偿于一体的集中式光纤放大器具有十分重要的意义。     

一种新型高双折射光子晶体光纤的特性研究

设计了一种新型结构的光子晶体光纤,建立了对应的数学模型并采用全矢量有限元法对该结构的模场强度、有效折射率、双折射、色散特性和限制损耗进行了分析。研究表明,该光纤在1 550nm处可以获得高达7.66×10-3的双折射和低至12ps/(nm·km)的色散值,同时在800～1 600nm波长范围内,始终保持1.498×10-6 dB/m以下的极低限制损耗,可用于制造极低色散值的保偏光纤。     

Design of low-confinement-loss and highly birefringent index-guiding photonic crystal fibers

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.     

新型大模场光子晶体光纤传输系统及其传输特性分析

通过在多模光子晶体光纤的两端分别连接一根单模光子晶体光纤,对其选择合适的参数,形成一种可以实现低弯曲损耗、大模场单模传输的光纤传输系统。运用数值仿真,分析了该传输系统在模场面积、弯曲损耗、连接损耗等方面的特性。研究结果表明,多模光子晶体光纤与单模光子晶体光纤所组成的系统可实现有效的单模传输;工作波长为1064nm时,多模光子晶体光纤在直波导状态时的基模模场面积可达1593μm2;在弯曲半径低至10cm时,多模光子晶体光纤仍然可以保持低损耗传输。经过对多模光子晶体光纤结构参数的优化,其与单模光子晶体光纤的连接损耗降低至0.085dB。     

大模场宽频单模光子晶体光纤的设计与制备

文章对无尽单模光子晶体光纤进行了理论设计,并提出了微结构光纤的制造工艺技术和相应的光纤拉丝工艺参数,制造出了较大模场的宽频单模光子晶体光纤,该光纤的芯直径为13.1 μm,微孔直径为3.2 μm,孔间距为8.2 μm,1 550 nm波长的模场直径为14.6 μm,1 550 nm的衰减为0.6 dB/km,1 383 nm水峰为14.9 dB/km.截止波长测试和近场光强分布检验表明,该光子晶体光纤确实具备较宽的单模工作范围.