函数缺陷对波导带隙结构的调制

Modulation of waveguide bandgap structure by function point defect

在二维函数光子晶体研究的基础上,进一步研究波导中加入两排函数线缺陷时,通过调节函数线缺陷的介质柱介电常数参数值,可实现波导带隙结构的调制情况.本文选取线缺陷介质柱介电常数函数形式为εr(r)=kr+b,其中,k为函数系数,b为参数.上述参量的变化,可由电光效应实现,即通过调节外加电场强度和电场分布来实现.当改变函数线缺陷介质柱介电常数参数k和b的值时,波导的带隙位置、带隙数目以及电场分布都会发生改变.因此,在波导中加入两排函数线缺陷就可实现带隙结构的调制,得到所需要的带隙结构和电场分布.这些结论可以为光学器件的设计提供理论基础和新的设计思路.

In this paper,the modulation of the photonic bandgap structure was studied by adjusting the dielectric constant parameters k and b of the point defect dielectric column when the two-dimensional photonic crystal waveguide added two row of function point defects close to center of the waveguide.The functions form of dielectric constant of dielectric column was ε r=kr+b, in which the parameters k and b could be realized by electro-optical effect.When dielectric constant parameters k and b of the point defect dielectric column changed,the bandgap position,bandgap number,the electric field distribution of the two-dimensional photonic crystal waveguide can be adjusted,i.e.,the photonic bandgap structure and the electric field position can be adjusted by changing the dielectric constant parameters k and b of the point defect dielectric column.This results will provide a theoretical basis and a new design idea for optical device design.