本文主要分析了弯曲波导损耗机理, 包括传输损耗、辐射损耗、模式转换损耗。重点综述了设计低损耗弯曲波导的方法, 包括波导材料、弯曲波导的曲线形状、波导种类、脊型波导的宽度、脊高、弯曲半径、模场分布、弯曲波导曲线形状和其他新型波导结构等。简要概括了近年来设计和制备低损耗弯曲波导的代表性工作。介绍了弯曲波导在集成光学中的应用。通过对弯曲波导的损耗及耦合机制理论的不断完善, 实现光在较小弯曲半径的低损耗传输, 从而提高集成光学的集成度是弯曲波导今后的发展趋势。

The loss mechanism of bent waveguide including the bending loss, propagation loss, radiation loss and the loss of mode conversion are theorically analysed in this paper . It focuses on the review of the design of low loss bent waveguide, including materials, the shape of bent waveguide, strip or rib waveguide, the width, height and radius of the bent waveguide, the dismatch of mode, the shape of the curve and other new structures. The representative works on the design and fabrication of low loss bent waveguides are summarized. The development status of the low loss bent waveguide is analysed and its applications in integrated optical are introduced. The future developing trend of bent waveguide is to develope the theory of the loss characterization and wave coupling, and to realize low bending loss with very small bending radii for high desity integration in Photonics Integrated Circuits(PICs).