利用传输矩阵法研究了液晶染料填充一维阶梯型Double-period第四代准周期结构局域模的光学特性。计算了增益前局域模与外加电场方向和正入射波方向间夹角θ的变化关系,分析了增益系数与局域模透射率的关系以及局域模在空间位置的光场分布,讨论了增益后的局域模透射率与光场强度的关系。结果表明:随着夹角θ的增大,光子禁带变宽并且只向短波方向拓展;随着夹角θ的增大,增益前的局域模向短波方向移动,透射率逐渐增大,且局域模波长的调控量为237 nm。随着增益系数的增大,透射率先增大后减小。光场分布呈现局域现象,当夹角θ=434°,波长λ=5950 nm时,光强达到6个数量级。增益后的局域模透射率与光场强度呈正比关系。

The optical characteristics of one-dimensional Ladder-type Double-period fourth generation quasi-periodic structures localized modes with dye-doped liquid crystal was studied with a transmission matrix method.and the relationship between localized modes before gained and the angle θ that the direction of applied electric field and direction of the positive incident wave were calculated,and the relationship between gain coefficient and transmittance of localized modes were analyzed with the optical field distribution of localized modes in the spatial location detected.The relationship between the light field strength and transmittance of localized modes after gained were discussed. The results showed that:the PBG were widened and only expanded to short-wave direction with the increasing of the angle θ,the localized modes which came before gained moved to the short-wave direction and the transmittance of localized modes gradually increased with the increasing of the angle θ.the regulation amount of localized modes wavelength was 237nm. The transmittance increased before decreased with the increasing of the gain coefficient.The optical field distribution presented a local phenomenon, the light intensity reached to six orders of magnitude when the angle θ was 434°, λ was 5950 nm.There was proportional relationship between light intensity and the transmittance of localized modes after gained.