二氧化锗空芯光纤的研制

建立了纯ＧｅＯ＿２空芯光纤的制作方法，分析了该种光纤的传光原理，计算了几种氧化物空芯光纤的模式损耗。测试了我们制作的纯ＧｅＯ＿２空芯光纤的传输损耗和传输功率，得到了较好的结果。     

介质(Ag/AgI)镀层空芯玻璃光纤的制备及红外传输性能的研究

介质（Ａｇ／ＡｇＩ）镀层空芯玻璃光纤是一种较好的传输红外激光的柔性光纤材料．采用液相化学沉积法成功地制备了内径分别为１．０、０．５３、０．３２ｍｍ,长度为１．５ｍ的介质（Ａｇ／ＡｇＩ）镀层玻璃空芯光纤．利用傅里叶红外光谱仪和 ＬＪＬ－３５Ａ ＣＯ_２激光器分别测试了介质（Ａｇ／ＡｇＩ）镀层玻璃空芯光纤的传输损耗,测试结果表明：介质（Ａｇ／ＡｇＩ）镀层空芯玻璃光纤在２．５～２０μｍ波长范围内有较低的损耗值;随着光纤内径（α）的增大,空芯光纤的传输损耗（α）降低,这与Ｍｉｇａｇｉ理论（α　∝１／α^３）相符合．另外,由于光纤的注入端头发热致使介质（Ａｇ／ＡｇＩ）镀层空芯玻璃光纤的传输损耗随注入功率的增加而增大．     

碳化硅内膜空芯传能光纤的研究

为了改进空芯传能光纤对10．6μm处CO2激光的传输性能，研制了具有SiC内膜的新型空芯玻璃波导，利用SEM和FTIR等技术分析了反应条件对sic膜层结构、物相的影响，并测试了光纤的性能．结果表明：温度是影响SiC膜层的重要因素；制得的孔径为950μm，长为2．5m的SiC传能光纤理论损耗约为0．7dB／m，实际传输损耗为0．74dB／m；SiC的吸收蜂有蓝移现象．     

空芯光纤中沉积多晶态GeO2薄膜的实验研究

通过缩短高温炉冷却器的距离,使化学反应与沉积区的温度梯度增加到约9℃／mm,进而使GeCl4与O2可在内径为1.0mm的空芯石英管内壁沉积上颗粒度约0.1um,厚度为3.0um的多晶态GeO2介质膜,使表面更加光滑,提高了光纤的传输性能,光纤的传输损耗小于0.8dB／m.     

外镀膜耐热空芯光导耐热性能的研究

太阳辐射光谱中红外光的能量约占太阳总辐射能的一半以上,玻璃光纤由于吸收损耗很难传输红外光;塑料光纤又承受不了太阳能产生的高温,本文介绍一种耐热温度高,传输效率高的传能光导-外镀膜耐热空芯光导.它是利用有机材料的高透光性能和无机材料的耐高温性能,在熔融条件下实现材料性能的重组,形成有机-无机复合耐热空芯光导,耐热温度可达150～200℃.由于光是在空芯内传播,光导的传光效率提高了20%～23%,而且可以传输红外光.本文重点分析了外镀膜耐热空芯光导的耐热性能.     

紫外光纤的激光传输特性测试

为适应紫外激光传输需要，试制了高透过紫外石英光纤，设计了实验装置，并测量了该种光纤的紫外传输损耗、弯曲损耗、激光损伤阈值和非线性光学效应，并与普通商用石英光纤作比较。分析并获得了紫外光纤的激光传输特性。     

铝膜紫外反射镜的高频等离子体阳极氧化技术

用高频等离子体阳极氧化技术，对铝膜紫外反射镜进行阳极氧化，得到紫外波段的反射率为６６％和９３％，它比单一的真空氧化铝膜的反射性能要好。在高频等离子体的阳极氧化中，尤以浮动氧化的反射性能更好（Ｒ＝９３％）．铝膜的紫外反射率和俄歇电子谱表明，氧的暴露量控制１００～２００Ｌ之间，能在铝膜外表面生长一层２２～３５ｕｍ的氧化铝保护膜，既能保持优异的反射特性，又有良好的抗腐蚀能力，是一种性能优越的紫外反射镜。     

PTB最新研制应用于深紫外光的空芯光纤

<正>据位于德国Erlangen的Max Planck光学研究所(MPL)和德国联邦物理技术研究院(PTB)量子和时空中心(QUEST)联合报道,用于深紫外光的空芯光纤的新的光波导器件可以提高物理、化学和生命研究的准确度。如果研究人员想以尽可能低的损耗通过光纤传输一束光,应选择红外光。然而,对于某些应用,例如离子或原子的光谱学研究,需要使用深紫外波段的激光,但是,这种光会很快损伤常规光纤。研究人     

铝膜反射镜空间环境适应性研究

铝膜反射镜是反射式空间聚光太阳电池阵的重要组成部分。通过对铝膜反射镜电子、质子、紫外、原子氧环境等一系列辐照及环境试验,研究和考察了铝膜反射镜反射率的变化和空间环境适应性。研究结果表明,铝膜反射镜适应地球同步轨道环境条件下,反射镜平均反射率在15年寿命末期大于75%;在低地球轨道环境中有必要对铝膜反射镜进行抗原子氧侵蚀防护。     

空芯光子带隙光纤及其传感技术

本文综述了空芯光子带隙光纤的独特性质,并介绍了近年来这类光纤在传感领域应用的新进展。光波在空气纤芯中低损耗传输是空芯光子带隙光纤的重要特性,它带来了长距离、大能量密度的光与物质相互作用通道,降低了光纤材料属性对传输光的影响(如中红外吸收、热光效应),为诸如痕量气体/液体探测、高精度光纤陀螺仪等传感应用提供了高效的新平台。空芯光子带隙光纤内部精细的微结构具有新颖的机械性能和热性能,有利于诸如声波、振动探测等传感应用;还可结合光纤后期热处理、选择性填充等技术,对多孔包层进行结构修改或材料填充,获得进一步的性能和功能扩展。这些灵活性已用于开发具有新特性的光纤器件,例如光栅、起偏器和偏振干涉仪。目前,空芯光子带隙光纤传感技术的发展已大大扩展了光纤的环境感知能力和应用范围,是全光器件和光集成技术发展的重要方向。

     

Interference Effects in Time-resolved Reflectivity Measurements in Thin Semiconductor Films

The study of non-equilibrium charge carriers in semiconductor films by time-resolved reflectivity measurements is greatly simplified if the change in reflectivity change varies linearly with the photoinduced change in refractive index. In the present work it is shown that interference effects in the transparent layer influence this dependence significantly. The sample reflectivity can either increase or decrease, depending on the film thickness. If the reciprocal absorption coefficient of the semiconductor is smaller than the film thickness, a refractive index profile is created inside the layer. The reflection at this profile diminishes the influence of the beams reflected at the semiconductor-substrate interface. The changes in reflectivity then vary linearly with the changes in refractive index, independently of the film thickness. Numerical calculations were performed to help interpret time-resolved reflectivity measurements on amorphous silicon films.     

Ray-optic analysis of the (bio)sensing ability of ring-cladding hollow waveguides

Ray-optic analysis of transmission spectra and the leakage loss of ring-cladding hollow waveguides suggests that such waveguides offer an attractive platform for the creation of compact and efficient biochemical sensors and sensor arrays. The ring cladding in such waveguides serves as a built-in Fabry-Perot interferometer, allowing the detection of few-nanometer-thick molecular layers and ensuring a high sensitivity of transmission spectra of waveguide modes to small changes in the refractive index of an analyte filling the hollow core and air holes in the waveguide cladding.     

pH对水热合成法制备铬渣源复合薄膜性能的影响

以铬渣为基本原料, 采用水热合成法制备了复合薄膜, 对样品进行了SEM、ICP、XRD、FT-IR及薄膜厚度表征分析, 以薄膜的折射率和反射率为对比参数, 研究了水热反应初始pH对薄膜的影响。研究结果表明, 当水热反应初始pH达11以上时, 薄膜表面呈现完美的空间三维立体网状结构; 当水热反应的pH为9、10时, 样品中形成了Al₂O₃、Fe₂O₃、Fe(OH)₃、Cr₂O₃、AlO(OH)和MgO晶体, 且其衍射峰较强; 样品内部纳米颗粒间存在毛细孔水和表面吸附水, 水热体系内的碱性基团促进膜物质与基底间形成化学键力的结合。薄膜越厚, 其折射率越小, 水热反应pH为11时, 薄膜最薄, 折射率最大; 水热反应的初始pH为12时制备的薄膜对紫外光反射率低于玻璃基底, 水热反应的初始pH为11时制备的薄膜对可见光的反射率小于玻璃基底。     

Planar optical waveguides formed in β-BBO by MeV O+ implantation

The planar waveguides have been fabricated in z-cut β-BaB₂O₄ crystal by 2.8 MeV O⁺ ion implantation with the doses of 8×10¹⁴ and 2×10¹⁵ ions/cm² at room temperature. The waveguides were characterized by the prism-coupling method. The dark modes are measured before and after the annealing at 300°C for 20 and 40 min in air. The refractive index profile is reconstructed using the reflectivity calculation method. It is found that relatively large positive changes of extraordinary refractive indices happen in the guiding regions, and a slight change increases with the doses, which are different from most of the observed ion-implanted waveguides.     

Synthesis of symmetric and asymmetric planar optical waveguides

A novel and accurate refractive index profile synthesis method for planar optical waveguides is presented and demonstrated using the transmitted near-electric-field-data. This method is based on the inverse transmission-line (TL) technique. From Maxwell's equations, a TL equivalent circuit (electric T-circuit) for the refractive index profile of a planar optical waveguide is derived. The authors demonstrate how to use this model to carry out the inverse problem and synthesise the exact refractive index profile numerically from near-field-data. The TL method can reconstruct arbitrary refractive index profiles for planar optical waveguides that support singlemode or multi- modes. The cases of both symmetric and asymmetric arbitrary refractive index profile planar waveguides are discussed. The accuracy of the reconstructed waveguides is examined numerically.     

Construction of refractive-index profiles of planar waveguides with additional information obtained from surface plasmon resonance

A surface plasmon resonance (SPR) is excited between a metal film and a graded-index planar waveguide. After the propagation constant of the SPR is measured, the refractive index near the surface of the waveguides, which is difficult to obtain by conventional techniques, is determined experimentally. With this nondestructive technique, combined with the inverse analytical transfer matrix method, the planar waveguide can be profiled to a high degree of accuracy.     

Planar optical waveguides formed in β-BBO by MeV O+ implantation

The planar waveguides have been fabricated in z-cut β-BaB₂O₄ crystal by 2.8 MeV O⁺ ion implantation with the doses of 8 × 10¹⁴ and 2 × 10¹⁵ ions/cm² at room temperature. The waveguides were characterized by the prism-coupling method. The dark modes are measured before and after the annealing at 300°C for 20 and 40 min in air. The refractive index profile is reconstructed using the reflectivity calculation method. It is found that relatively large positive changes of extraordinary refractive indices happen in the guiding regions, and a slight change increases with the doses, which are different from most of the observed ion-implanted waveguides.     

Optical interference phenomena in silicon films on oxidized silicon and similar two-film systems

In certain thickness ranges, the curves of reflectivity versus wave number for silicon films deposited on oxidized silicon, and for other similar two-film systems, resemble beats. If the oxide thickness is not too large, the values of the wave number at the extremes of the reflectivity can be described in terms of almost quarter odd-order numbers and an additional thickness for the optically effective thickness of the silicon film. A simple graphical evaluation method for the thickness of the silicon film with known refractive index is derived. If the oxide thickness is not too small, it too can be measured.     

Thickness and uniformity of fluorocarbon polymer film dynamically coated inside silver hollow glass waveguides

The variation in properties of a fluorocarbon polymer (FCP) film during a drying-curing process is investigated for fabricating FCP-coated silver (FCP/Ag) hollow glass waveguides. A dynamic liquid-phase coating procedure is used. Through the analyses of the loss spectra of hollow waveguides made in various conditions, a relationship between the thickness of the FCP film and the coating velocity is obtained. The optimum fabrication condition is also established for producing FCP/Ag hollow glass waveguides for the mid-IR.     

溶胶-凝胶法制备全反射型CO2激光空芯波导的可行性分析

通过对CO2激光空芯导研究现状的分析,指出了全拓射型空芯导目前所面临的问题,在此基础上结合溶胶－凝胶法的特点,提出了用溶胶－凝胶法制备全反射型CO2激光空芯波导反常色散膜的新思想,并分析了其在原理、工艺及光学上的可行性。