光子晶体薄板波导导模的固有损耗特性研究

Intrinsic losses of guided modes in photonic crystal slab waveguides

利用波导模展开法计算了强介质比光子晶体薄板波导中的固有损耗。在导模高群速度的频段中,辐射损耗随着晶体中空气比的增加而增加,随着波导宽度的增加或薄板厚度的增加而减小,而且可以计算得到在靠近模式色散中微小带隙处的损耗与复频率的关系,计算得到的损耗与Si薄板中所测的结果十分吻合。

Intrinsic losses of guided modes in photonic crystal slab waveguides with strong refractive index contrast were calculated by using the guided mode expression method. In the frequency region of high group velocity of the guided mode, the radiative losses increase with the air fraction of the lattice and decrease on increasing the channel width or the slab thickness. Close to a mini-gap in the mode dispersion, a complex frequency dependence of the losses is found. The calculated losses agree well with those measured in a Si slab.