中文摘要：

提出了一种基于六角格子光子晶体波导微腔和Fabry-Perot（FP）腔非对称耦合的全光二极管结构,它由一个包含非线性Kerr介质的高Q值微腔与一个光子晶体波导中的FP腔组成.通过有限时域差分方法对其传输特性进行了仿真,发现通过两腔的非对称耦合可以实现在特定光强度下的正向传输、反向截止的功能.在靠近微腔方向光入射时,特定强度的光可以激发非线性微腔的Kerr效应,改变了Fano腔的共振频率,从而变成透射状态.而远离微腔方向光入射,由于这个不对称的结构造成场局域的分布不对称,激发微腔Kerr效应的光强还不够,所以光不能透射.所设计的全光二极管结构具有良好的性能参数：最大透射率高和高透射比、光强阈值低和易于集成等。

英文摘要：

A high efficiency all-optical diode based on 2D hexagonal lattice photonic crystal（PC） waveguide is proposed. The structure is asymmetrically coupled by a high Q factor micro-cavity-containing nonlinear Kerr medium and a FabryPerot cavity in PC waveguide. The transmission properties are numerically investigated by finite-difference time-domain（FDTD） method. Because of interference between the two cavities, the structure can achieve the function of forward transmission and backward cut-off under a suitable light intensity. For light incidence close to the direction of microcavity, nonlinear Kerr effect of micro-cavity can be excited by a certain light intensity. Then the resonant frequency of Fano cavity will change and forward incidence becomes transmission from reflective state. But for light incidence away from the direction of micro-cavity, the field distribution is asymmetric due to the asymmetric structure, so backward incidence needs stronger incidence light to excite Kerr effect and keeps reflective state. This design of all-optical diode has many advantages, including high maximum transmittance, high transmittance contrast ratio, low power threshold,and ease of integration, and so on.