Analysis, Design, Fabrication of 3-D Waveguide Type Optical Planar Circuit having Strong Confinement of Optical Field

这项研究是为期两年的项目。本研究的目的是(1)基于表面波平面电路的概念，研究具有精细结构的三维波导型光学平面电路元件在高度和横向上强烈限制光场的可能性或潜力。(2)利用电子束光刻技术制作相应的三维光波导元件并进行测试。(3)从理论分析、制作工艺和测量三个方面对问题进行了讨论和评价。第二年取得了以下结果：(A)三维光波导宽度阶跃不连续的三维场分析，有望在集成的三维光波导电路中实现类似于微波电路的单模操作。在这种情况下，阶跃不连续处的场扰动将成为一个严重的问题。提出了基于表面波平面电路方程的三维矢量分析方法，并将其应用于康奈尔…两种不同宽度的三维光波导的最大功率值从1.5微米到2.5微米不等。(2)精细结构波导型光路元件的分析、制作、测试与评价。传统的三层或四层三维光波导能实现对光场的强约束，但由于TE模和TM模的简并倾向，很难实现单模工作。通过控制超薄膜多层结构中的层数，可以实现强模式分离。这一结果也被我们的实验所证实。通过测量条纹光来评估传输损耗，结果表明TE比TM损耗更大，损耗为2.7db/cm。项目资金引进了电子束曝光设备的圆曲线图案化系统，该系统将用于制作包括圆弯在内的更有用的三维光学电路元件。较少

The research is the two year project. The aims of this research are (1) Investigation of the possibility or the potential of 3-D wave-guided-type optical planar circuit element having a fine structure to confine the optical field strongly in height and transverse direction based on concept of the surface-wave planar circuit. (2) Fabrication of the corresponding 3-D optical waveguide element by electron beam lithography and measurement. (3) Discussion and evaluation of the problems is theoretical analysis, fabrication process and measurements.In this second year following results are obtained.(A) 3-D field analysis of Step discontinuity in width for 3-D optical waveguide.Single mode operation similar to microwave circuit is expected to be realized in an integrated 3-D optical waveguide circuit. In this case field disturbance at the step discontinuity will become a serious problem. The 3-D vector analysis based on surface wave planar circuit equations is proposed and applied to the conne … More ction of two 3-D optical waveguides of different width ranged from 1.5 mum to 2.5 mum. Extending the concept of the surface-wave planar circuit, reasonable design of the true passive optical integrated circuit will be possible, where the field disturbance is exactly considered or microwave circuit design concept is introduced.(B) Analysis, Fabrication, Measurement and Evaluation of waveguide type optical circuit element having fine structure.The conventional three or four layers 3-D optical waveguide can realize a strong confinement of the optical field but is difficult to realize the single mode operation because the degenerate tendency of the TE and TM modes. Strong mode separation can be realized by controlling the number of layers in the multilayered structure of very thin films. This result is also confirmed by our experiments. Evaluation of propagation loss by measuring the streak light shows that TE is more lossy than TM and is 2.7 db/cm in loss. Circular curve patterning system for electron beam exposing equipment was introduced by the project money, which will be used for fabrication of more useful 3-D optical circuit element including circular bend. Less