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     

Ultrahigh birefringent nonlinear microstructured fiber

In this letter, we present the fabrication of a microstructured fiber with high birefringence suitable for nonlinear applications. The fiber has been fabricated adapting the stack and draw method for microstructured fibers. The birefringence of the fiber is achieved inducing ellipticity to the air-hole array by controlling the lateral tension between preform and jacketing tube. Values of the group index birefringence higher than 7/spl times/10/sup -3/ are demonstrated.     

开放式微结构光纤研究

与传统微结构光纤相比,开放式微结构光纤不仅保持了可通过灵活的几何结构设计,从而获得优化光学传感性能的优点,利用其开放式无需预填充的特点,还可较大幅度地提高传感实时工作效率。本文对近年来出现的几种具有代表性的开放式微结构光纤进行了讨论。比较了利用开放全内反射型、WagonV％甜型及嵌入导流孔型开放式微结构光纤作为实时气液传感器时各自的优缺点。研究表明,这几种开放式微结构光纤都在气液实时传感领域显示了较为独特的优点。借助于开放式微结构光纤,可为未来高精度实时光纤传感器领域的设计提供一种较有竞争力的技术支撑。     

Reduced loss in extruded soft glass microstructured fibre

The fabrication of small core high-NA soft glass microstructured optical fibres with propagation loss as low as 0.6 dB/m at 1100 nm is reported. Advances in soft glass preform extrusion and fibre fabrication have allowed the first demonstration that extrusion does not significantly contribute to the fibre loss.     

频率可调太赫兹微结构光电导天线

太赫兹波低频段辐射计在地球大气和分子探测中的需求不断增加。在微波电开口谐振环等效电路模型及其谐振特性仿真设计的基础上,将微波谐振结构和传统带状线偶极子光电导天线结合,提出了新型微结构光电导天线,具有频率调节灵敏度高、谐振特性明显的优点。加工了不同尺寸的新型光电导天线和常规的带状线偶极子光电导天线实物,并进行了实验对比研究。两种类型的太赫兹辐射频谱明显不同,新型光电导天线由于微结构电开口谐振环的双频谐振特性出现了两个谐振峰,3 dB相对带宽约为50%,得到了窄带特性;而传统光电导天线只有单峰,3 dB相对带宽为93.07%,显然为宽谱特性。对于新型光电导天线的仿真和实测吻合较好,调节微结构天线的谐振环臂长可以获得较大的峰值频率移动相对值,从而也验证了理论模型、谐振单元仿真结果的有效性。     

环氧树脂/氧化铝复合材料的制备及导热模型

采用浇注成型法制备了环氧树脂/氧化铝复合材料,研究了氧化铝含量对所制复合材料导热、介电以及力学性能的影响.结果显示:当氧化铝含量小于体积分数0.3时,所制复合材料导热系数与Maxwell方程的计算值比较吻合,而混联模型更适合于预测氧化铝含量较高时的导热系数;该复合材料的介电常数随着氧化铝含量的增加而增加,弯曲强度随氧化...     

Fabrication of microstructured polymer optical fibres

A methodology is presented suitable for the fabrication of a wide range of microstructured polymer optical fibres (mPOFs), a recent development where light guidance is achieved through the incorporation of a pattern of air channels that run the entire length of the fibre. We show that the key to good mPOF fabrication is a secondary draw oven that has tight control over the length (15–20 mm) and temperature (C) of the hot-zone while maintaining fibre draw tension high enough (50–150 g) to ensure an acceptable level of partial hole collapse (30–40%) due to surface tension effects. Diverse mPOFs with diameters in the range 200–1200 μm have been fabricated with typical standard deviations of 2–3 μm.     

在微结构光纤中实现四进制向二进制的全光转换

提出并实验了一种基于高非线性色散平坦微结构光纤的四进制光信号向二进制光信号的全光转换方案。由于自相位调制(SPM)效应,不同峰值功率的ps光脉冲经过微结构光纤传输后可获得不同展宽程度的输出频谱。基于以上原理,通过滤波可将1路10Gb/s的四进制信号转化成3路不同波长的10Gb/s二进制信号,再将3路信号进行适当的时延和衰减,最后耦合成为1路20Gb/s的二进制信号,实验获得的转换信号消光比达到3.2dB。     

空芯光子晶体光纤的塌缩及选择性液体填充

研究了一种空芯光子晶体光纤(HC-PCF)的微孔塌缩特性,所用设备为传统光纤熔接机,对塌缩后的光纤实现了液体的选择性填充。并通过有限元法仿真分析了该空芯光纤在液体填充前后的基本参数:有效折射率、模场有效面积、数值孔径。通过仿真对比发现空芯光纤在中心孔选择性液体填充后非线性效应增大;通过实验得出了最佳光纤塌缩参数为光纤端面距离放电中心距离为50 μm,放电时间800 ms,放电强度为15.5 mA。     

Tunable highly birefringent bandgap-guiding liquid-crystal microstructured fibers

A new type of nematic liquid-crystal infiltrated photonic bandgap-guiding fiber for single polarization or high-birefringence guidance is proposed. Numerical studies demonstrate that modal birefringence can be tuned by proper selection of the structural and material parameters as well as by the application of an external electric field in conjunction with the specific liquid-crystal anchoring conditions.     

微结构聚合物光纤制备技术研究

微结构聚合物光纤以其制备工艺简单,实用性强而倍受研究人员关注。在国家自然科学重点基金的资助下,提出了微结构聚合物光纤预制棒的化学原位本体聚合技术和PMMA颗粒料挤出技术以及微结构聚合物光纤预制棒的套管法二次拉伸技术,成功制备了微结构掺诺丹明6G型、椭圆芯高双折射型、无限单模型和布拉格光栅光纤型等各种微结构聚合物光纤。通过对微结构聚合物光纤制备工艺的研究,对几种已经成功开发的微结构聚合物光纤进行报道。     

Recent progress in microstructured polymer optical fibre fabrication and characterisation

Recent progress in microstructured polymer optical fibre fabrication and characterisation will be presented. A wide range of different optical functionalities can now be obtained by modifications of the microstructure, as is demonstrated by the fibres presented here. Microstructured fibres that are single-mode, highly birefringent or show twin-core coupling are described, in addition to graded-index microstructured fibres and hollow core fibres, the latter case being where light is guided in an air core. Microstructured polymer optical fibres are an exciting new development, offering opportunities to develop fibres for a wide range of applications in telecommunications and optical sensing.     

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…     

Simulation of the properties of microstructured optical fibers

A new method for calculating the radiation loss and chromatic dispersion of leaky modes propagating in microstructured (holey) optical fibers (MOFs) with circular air-filled channels is proposed and implemented numerically. It is shown that the results are in good agreement with both the known numerical data and with the experimental data obtained for two types of fabricated MOFs that contain, respectively, 30 and 60 channels.     

微结构光纤制备中的问题分析

分析了微结构光纤制备过程中存在的一些问题,简述了温度、空气孔中的空气压力、表面张力等因素对微结构光纤中毛细管形变的影响.建立了可行的制备技术工艺路线.同时比较了微结构光纤预制棒制作的不同方法,详细介绍了改进的堆积法方案.     

Phonon spectroscopy of the nano- and microstructured ceramics

A relation of the diffusion coefficient of the subterahertz thermal phonons with the system of intergrain boundaries, grain size and structure, and the technological conditions for the synthesis of ceramics is established. It is demonstrated that the temperature dependence of the phonon diffusion coefficient at liquid-helium temperatures is determined by the spectral properties of the intergrain layer, which makes it possible to estimate the sample-averaged thickness and acoustic impedance. The conditions for and properties of the gap in the natural phonon spectrum of ceramics are studied. Specific features of the transport of sub-terahertz phonons in ceramic samples based on ferroelectric materials, solid solutions of electrolytes, and cermets are analyzed.     

碲化物微结构光纤应用于中红外超连续谱的产生

由于强的红外吸收,石英玻璃材料拉制成的光纤或微结构光纤在中红外波段的传输损耗很大.为产生中红外波段的超连续谱,须使用在该波段具有高透过率的非石英材料来拉制光纤或微结构光纤.碲化物材料本身具有高非线性,所以光纤色散设计是实现宽带、平坦超连续谱输出的重要条件.为了实现全光纤结构的超连续光源,选用1.55 μm和2.0 μm...     

Rectangular-core microstructured polymer optical fibre for interconnect applications

A multimode microstructured polymer optical fibre is presented in which a large rectangular core is suspended by thin supporting bridges. Measurements of the near- and far-field patterns, the numerical aperture and polarisation mode-mixing are presented.     

微构造硅表面形貌的陷光特性研究

在特定的气体氛围下,用一定能量密度的飞秒激光连续照射单晶硅片表面,可制备出表面具有准规则排列微米量级锥形尖峰结构的黑硅材料。利用几何光学中光的传输理论,研究了黑硅材料的陷光特性,以及黑硅表面准规则排列的微米量级锥形尖峰结构的形状和密度对反射次数的影响。获得黑硅的表面准规则排列的微米量级锥形尖峰结构的高度越高、间距越小和底角越大,它的陷光效果就越好的结论。