摘要：近年来，用光子晶体实现光波导，具有良好的波导性质，已经实现了广泛的应用。随着光子晶体的高速发展，人们提出了一种新的结构的光波导—耦合腔波导。本文用时域有限差分法研究了光子晶体耦合腔波导，通过设计耦合腔波导的结构，改变其微腔中心圆柱的半径，发现它是对波导模产生影响的重要参数。我们首先计算完整光子晶体的透过率。光子晶体由空气中周期排列的Si（11.56）柱组成，晶格常数a为494nm。本文中计算了选取的两种光子晶体耦合腔波导结构下的几组计算数据，从中，通过比较发现波导模随着随着圆柱半径而变化，得到与波导模的关系。接着比较两种结构间在同样圆柱半径的情况下波导的模宽度的比较。这些研究结果对耦合腔波导的设计与加工有着重要的指导意义。

关键词：光子晶体；耦合腔波导；时域有限差分法

Abstract: In recent years, the use of photonic crystal to realize optical waveguide could achieve excellent performance and has been used extensively in many areas. With the high speed development of photonic crystals, people proposed a new structure of optical waveguide-coupled cavity waveguide. In this paper we study the photonic crystal coupled cavity waveguide. By changing the radius of the cylinder in the cavity center and study the transmission of the waveguide, we find that this radius is a critical parameter. We first calculate the transmission of complete photonic crystals. Photonic crystals are composed of periodic Si (11.56) cylinders in the air, and the lattice constant a is 494 nm. This paper study two kinds of photonic crystal coupling cavity waveguide, from which, we find the relations between the waveguide mode and the radius of the central cylinder of the cavities. We also compare the width of the two kinds of waveguide modes. These results have important applications in design and fabrication coupled cavity photonic crystal waveguides.

Key words: Photonic crystal; Coupled cavity waveguide; Finite-difference time-domain method