高性能Ag/AgI红外空芯光纤的研究

采用液相化学镀膜法研制了内面镀有银膜和碘化银膜(Ag/AgI)的高性能空芯红外光纤.分析了绿色导航光和红外激光同时低损耗传输的光纤结构参量.长度1 m、内直径0.7 mm的Ag/AgI空芯光纤不仅在红外有低损耗传输特性,而且首次在波长530 nm处获得了7 dB/m的低传输损耗特性.满足可见光作为导航光的同轴传输要求.通过分析和改进实验工艺参量,有效降低Ag和AgI薄膜的表面粗糙度.给出了高性能Ag/AgI空芯光纤的介质镀膜的具体工艺参量.     

Polarization conversion at the discontinuities in semiconductor opto-electronic systems

The origin of unexpected polarization conversion at the junctions between two semiconductor rib waveguides is demonstrated by using full-vectorial numerical approaches.     

Electrical pumping of a third-order mode semiconductor laser

AlGaAs-based quantum well laser structures with third-order waveguide mode emission at 775 nm are a promising route toward compact twin-photon sources at 1.55 μm based on the principle of modal phase matching between the pumping frequency and fundamental modes at half frequency in III–V semiconductor waveguides. Following the demonstration and characterization of an optically pumped third-order mode semiconductor laser, in this paper we present data of the corresponding structure under conditions of electrical pumping. By pumping electrically and optically the same sample made for current injection, identical transverse far-field angular laser mode profiles are measured and with very low parasitic losses. Although they do not follow the third-order mode emission pattern as it is expected, however this means that the different way of pumping, that of the electrical one as compared to optical pumping is not responsible for the absence of third-order mode emission. Furthermore, since the undoped optically pumped laser sample correctly emits on the third-order mode, it is concluded that the cladding layers of the structure still need to be optimized in doping and thickness, in order to reduce the internal losses for the third-order mode.     

New Criterion for Designing Silica Multimode Interference Power Splitters

We introduce a new criterion for designing 1 × N silica multimode interference power splitters using overlapping-image multimode interference analysis. This criterion requires that widths of multimode waveguides in the devices should be greater than 2 times the product of port number N and effective widths of output waveguides. Better device uniformity can be achieved when the new criterion is satisfied.     

改进WKB近似的新方法

利用转移矩阵理论，在考虑层间一次反射和转折点处实际相移的基础上，导出了改进的ＷＫＢ公式，数值计算的结果表明本文所得公式的精度远优于传统的ＷＫＢ近似，而且能适用于接近于截止的模式和变化剧烈的折射率分布。     

MgO:LiNb0.3与LiNb0.3质子交换光波导光学及结构特征的比较

利用退火的质子交换法在MgO:LiNbO.3和LiNbO.3两种材料上制作了光波导，得到了质子交换的扩散特性以及光波导折射率分布的退火规律．通过x射线衍射和OH-红外吸收谱方法研究了 MgO:LiNbO.3和LiNbO.3质子交换光波导的结构特征及其与退火参数的关系，对MgO :LiNbO.3和LiNbO.3光波导光学和结构特征的结果进行了分析和比较． 关键词： 退火质子交换光波导 晶格结构 x射线衍射 红外吸收     

Analysis for dispersion characteristics of elliptic- and parabolic-groove waveguides

In this paper, the dispersion characteristics of elliptic-and parabolic-groove guides are analysed by using the equivalent network method with rectangular step approximation. The results have important values in the studying of the transmission characteristics of curvilineal-groove guides as well as its manufacture and application.     

Transmission of 1.6 J Er:YAG laser light by ZnS-coated silver hollow waveguides

A maximum energy of 1.6 J at 5 pps of Er:YAG laser light has been transmitted through a flexible ZnS-coated silver hollow waveguide which has an inner diameter of 800 μm and is 116 cm long. The straight waveguide loss is 0.6 dB m⁻¹ and no significant loss and mechanical changes have been found after an endurance test of 10000 pulse transmissions and bending 400 times with a bending radius of 30 cm.     

(Al)GaAs/AlGaAs周期光波导中的等幅基模

本文应用周期介质光波导的模场分布函数和特征方程分析了(Al)GaAs/AlGaAs周期光波导中结构参量及介质折射率对模场分布形状的影响,研究了波导中形成等幅基模的条件,讨论了相应参量的优化选择。     

光束传播法分析硅交叉波导光开关的光学效应

运用光束传播法对硅交叉波导全内反射光开关中的光学效应进行了详细分析。结果表明：１）光学表面衰减波和泄漏波所引发的光遂道效应对开关特性有重要影响；２）反射端功率的相对大小于与反射区界面位置密切相关，其起因是古斯－汉欣位移；３）合理考虑这些因素的影响可以大大降低器件对折射率变化的要求。