微结构光纤激光器件

由于微结构光纤灵活多变的结构特点,使得以其为增益介质的光纤激光器件,具有比普通光纤激光器件更加优异的性能.本文结合国际上微结构光纤激光器件的最新研究进展情况,概述了微结构光纤作为增益介质的独特特性、微结构光纤激光器件的理论分析方法和掺铒、掺镱以及喇曼微结构光纤激光器件的特点.     

面向光纤陀螺发展需求的空芯微结构光纤的弯曲特性研究

空芯微结构光纤的弯曲损耗是决定其能否真正应用到光纤陀螺中的一个核心指标。设计并成功拉制出一款具有超低弯曲损耗的19芯空芯光子带隙光纤，通过与拉制的具有相近纤芯直径的空芯反谐振光纤进行对比，详细探究了空芯微结构光纤弯曲损耗的产生机理，证明了空芯光子带隙光纤具有更优异的抗弯曲特性。使用对称缠绕法，在0.25 cm的极限弯曲半径下，实验测量得到的空芯光子带隙光纤的弯曲损耗为每圈3.63×10^-3 dB@1624 nm，这是目前实验报道的空芯微结构光纤在最小弯曲半径下的最低弯曲损耗。面向光纤陀螺的应用需求，首次实验研究了在不同张力下空芯光子带隙光纤敏感环的插入损耗的变化情况。研究结果显示，随着绕制张力的增加，环体插入损耗显著增加，因此宜在小张力条件下进行空芯光子带隙光纤敏感环的绕制。研究成果对空芯微结构光纤在光纤陀螺领域的实用化进程有着重要的推进作用。     

微结构光纤在光通信中的应用实验

微结构光纤是新兴的研究领域．特殊微结构所赋予的诸多新奇性,使得微结构光纤不仅可以成为优异的光传输介质,而且可以用来制作各种新型的光纤器件．文章介绍了微结构光纤在光传输和光纤器件方面的最新实验研究．     

微结构光纤的有限元分析计算法

利用有限元法对零色散点在780nm的均匀微结构光纤进行经过简化的矢量波动方程模拟计算，获得了所需要的模场分布、有效折射率、色散、有效模面积等参数，并与实验数据相参照验证了这种方法的准确性和精度。进而将这种计算方法用于非均匀微结构光纤的模拟计算，不仅获得了很好的结果，与其他方法相比还具有更快的计算速度，计算所得到的结果对将来设计和拉制微结构光纤很有帮助，并且这种方法在设计不规则的微结构光纤方面具有很好的优势。     

大尺寸气孔微结构光纤在光纤光栅中的应用

将微结构光纤分为光子晶体光纤和大尺寸气孔微结构光纤两种。详细介绍了大尺寸气孔微结构光纤。其包层的气孔硅结构（或者聚合物硅结构）影响了包层模式的空间分布以及包层模式的有效折射率，使其表现出与传统光纤不同的光学特性。基于这种微结构光纤的光纤光栅对外部折射率的变化显示了很好的稳定性。偏振特性（对长周期光纤光栅）可以大大加强。基于聚合物硅包层的长周期光纤光栅显示了优良的温度调谐性能。     

微结构聚合物光纤制造和性能方面的最新进展

介绍了微结构聚合物光纤制造和性能方面的最新进展。如文中所介绍光纤证实的，通过改进微结构，可以获碍许多不同的光学功能。除渐变折射率微结构光纤和光在空气芯中传导的空芯光纤之外，还介绍了单模、高双折射和表现为双芯耦合的微结构光纤。微结构聚合物光纤是一种新型设计。它为开发适于电信和光学传感等广泛应用领域的光纤创造了机会。     

单偏振单模微结构聚合物光纤的设计

设计了一种聚甲基丙烯酸甲酯(PMMA)基的单偏振单模(SPSM)微结构聚合物光纤(MPOF)。采用全矢量平面波展开法并结合完美匹配边界条件,对其偏振特性进行了理论模拟。详细讨论了微结构光纤参数的变化对单偏振单模带宽和工作波长的影响,发现在0.57～0.71μm的可见光波长范围,由于基模两个正交偏振模的截止波长不同,这种微结构聚合物光纤只能传输基模中的一个偏振模。光束传播法计算表明,在波长0.65μm处具有7圈空气孔的单偏振单模微结构聚合物光纤的传导偏振模约束损耗仅为1.24dB/m,这种低损耗的单偏振单模微结构聚合物光纤可有效消除传统保偏光纤固有的偏振串扰和偏振模色散。     

微结构色散补偿光纤结构特性的研究

由于微结构光纤奇异的色散特性,使得它在对常规通信光纤的色散补偿应用中具有很大的潜力.均匀规则六角形排列的微结构光纤(MSF)在大孔径比d/∧和小空气孔间隔∧情况下具有大负色散值.只要合理设计其几何尺寸,其它排列的晶格阵列的微结构光纤也可以具有大负色散特性,例如双芯六角形晶格MSF,双芯圆形晶格MSF,方形、蜂窝形等.     

微结构掺镱双包层光纤的研究

近年来掺健光纤激光器的研究有了较大发展,出现了用于高功率光纤激光器的双包层掺镱光纤(DCYDF)。双包层掺镱光纤的纤芯作为单模波导用于传输信号光。．内包层设计为多模波导用于传输泵浦光。由于微结构光纤具有可控的周期性折射率并且其模场面积可通过结构参数的调整而加以控制．因此这类光纤在光纤激光器和放大器中有着广泛的应用前景。文章作者根据高功率光纤激光器的性能要求．设计和制备了内包层为D形和六边形的微结构掺镱双包层光纤。     

微结构光纤及其双折射特性的研究

主要对微结构光纤以及其双折射特性研究情况进行总结，首先介绍了微结构光纤的研究历程和基本概念，然后重点总结了微结构光纤的解析和数值分析方法，接着介绍了高双折射微结构光纤设计和最新研究进展，最后对微结构光纤的应用和研究前景进行了展望。     

Nonlinear optical devices based on suspended-core microstructured optical fibers

Suspended-core microstructured optical fibers are employed in lasers that generate ultrashort pulses and supercontinuum generators. It is demonstrated that a femtosecond fiber laser based on the ytterbium-doped microstructured fiber generates pulses with a duration of 95 fs at a wavelength of 1045 nm and a mean power of 5 mW in the absence of additional compression. Supercontinuum is generated in tapered microstructured fibers with suspended core in the wavelength interval 400–1400 nm. Suspended-core micro-structured fibers may serve as promising elements for nonlinear optical devices due to specific waveguide characteristics, relative simplicity of manufacturing, and variable optical properties.     

Mode coupling of microstructured optical fibers using temperature-dependent nitrogen-doped silica fibers

A promising method for the diminishing of loss upon the welding of microstructured optical fibers with suspended core is proposed. The method is based on the application of the nitrogen-doped optical fiber whose thermally expanding core serves as the mode coupler. The loss related to the welding of the conventional fiber (Corning SMF-28 and OFS Clearlite 980) and the suspended-core microstructured fiber (with a core diameter of about 2 μm at wavelengths of 1060, 1310, and 1550 nm) using a conventional welding device is experimentally studied. The welding loss (less than 0.5 dB) in a wide spectral range is several times less than the loss corresponding to the existing methods for the coupling of conventional and microstructures fibers.     

Adiabatic coupling in tapered air-silica microstructured opticalfiber

We study adiabatic mode propagation in tapered air-silica microstructured optical fibers and demonstrate efficient coupling into a robust high-delta microstructured fiber. In the waist region of the taper, the core mode is tightly confined by the air holes and exhibits properties similar to a high-delta waveguide such as enhanced peak intensity and widely flattened anomalous dispersion. We exploit these properties to generate tunable self-frequency shifting Raman solitons over the communications window from 1.3 μm to 1.65 μm, with over 60% conversion efficiency These fiber devices are practical for several reasons: they can be fusion spliced to standard single-mode fibers with relatively low loss, they are mechanically strong, due to the supporting cladding, and because the mode is isolated from the surrounding air interface, they can potentially be recoated allowing for packaging     

Elliptical hollow core tube lattice fibers for terahertz applications

Hollow core microstructured fibers whose cladding is composed by an elliptical arrangement of circular dielectric tubes are numerically investigated. Birefringence, differential group delay, and polarization dependent loss are evaluated for different values of ellipticity in order to quantify its effect on the two polarizations of the fundamental core mode. All these parameters have a minimum at the center of each transmission window and they assume maximum values at the edges. In particular, the birefringence goes always to zero irrespective of ellipticity. This proves that tube lattice fibers are strongly immune against unwanted core shape deformation, in particular when the working frequency is close to the center of the transmission windows. On the other hand they are not suitable to obtain polarization maintaining fibers.     

Microcavities Using Holey Fibers

Microcavities consisting of microstructured holey fibers and separate end mirrors have been constructed and tested. These devices exhibit excellent transverse-mode confinement and the ability to control the percentage of power guided outside of the fiber core. As a result, these devices may be a useful tool for enhancing the interaction between light and an atomic medium.     

THz波微结构器件特性的研究

在电磁波谱中所处的特殊位置使得THz波在在物理、化学、生物医学、电子科学、材料科学、环境监测等领域有着广泛的应用前景。综述了THz波微结构器件特性方面的研究工作。亚波长金属周期微结构器件的THz波谱选择增强透射现象,亚波长环形槽金属线上的THz等效表面等离子体激元,以及THz光子晶体光纤。     

聚合物微结构光纤型可调衰减器的研究

设计了一种基于聚合物微结构光纤(PMOF)及液晶选择注入技术的温控可调衰减器.拉制了高质量的聚甲基丙烯酸甲酯(PMMA)PMOF,并在光纤微孔中实现了选择性注入液晶5CB,制作了温控可调衰减器,器件消光比超过60 dB.实验结果与理论设计基本吻合.     

Investigation of all-optical regeneration based on self-phase modulation in microstructured fibers

All-optical regeneration is critical for future high bit rate optical communication systems since current electronic re- generation is not transparent to optical signal and limited by the current electronic processing speeds. All-optical regen- eration ba…     

Tunable attenuator based on polymer microstructured optical fibers

The polymer microstructured optical fiber is a kind of fiber whose core and cladding are composed of air holes and organic compornoleel by a certain rule. Similar with silica microstructured optical fibers (SMOF), according to the light guide mechanism PM…