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

这项研究是一个为期两年的项目。本研究的目的是：(1)基于表面波平面电路的概念，探讨具有良好结构的三维波导型光学平面电路元件在高度和横向上对光场产生强烈限制的可能性或潜力。(2)利用电子束光刻和测量技术制作相应的三维光波导元件。(3)对问题进行理论分析、制作工艺和测量的讨论和评价。在这第二年，获得了以下结果。(A)三维光波导宽度阶跃不连续的三维场分析。在集成三维光波导电路中，有望实现类似微波电路的单模工作。在这种情况下，在阶跃不连续处的场扰动将成为一个严重的问题。提出了一种基于面波平面电路方程的三维矢量分析方法，并将其应用于1.5 ~ 2.5 μ m两种不同宽度的三维光波导的锥作用。扩展表面波平面电路的概念，在充分考虑场干扰或引入微波电路设计概念的情况下，才有可能合理设计出真正的无源光集成电路。（二）具有优良结构的波导型光电路元件的分析、制造、测量与评价。传统的三层或四层三维光波导可以实现对光场的强约束，但由于TE和TM模式的简并倾向，难以实现单模工作。通过控制超薄薄膜多层结构中的层数，可以实现强模式分离。我们的实验也证实了这一结果。通过测量条纹光来评估传输损耗，表明TE比TM更有损耗，损耗为2.7 db/cm。本项目介绍了电子束暴露设备的圆形曲线图像化系统，该系统将用于制造更实用的三维光学元件，包括圆形弯曲。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