四元镜像对称结构光子晶体的光学滤波特性

The optical filtering characteristics of four-element mirror symmetry structure photonic crystal

通过传输矩阵法理论,研究四元镜像对称结构光子晶体(BCD)_7A(DCB)_7的光传输特性,结果表明,光子晶体可实现双通道窄带光学滤波功能,而且两通道的光学滤波特性对各薄膜介质层的物理厚度响应很灵敏,但响应机制不尽相同。对于短波滤波通道,滤波品质因子Q随B、C、D介质层物理厚度d_B、d_C和d_D的增大而下降,其中Q随d_C增大下降速度最快,随d_D增大下降速度次之,随d_B增大下降速度最慢,但滤波品质因子Q随A介质层物理厚度d_A增大而快速提高。对于长波滤波通道,滤波品质因子Q随B、D介质层物理厚度d_B、d_D的增大而快速提高,其中Q随d_D增大提高速度最快,随d_B增大提高速度次之,但滤波品质因子Q随C、A介质层物理厚度d_C、d_A增大而下降。此外,随着各介质层物理厚度的增加,双滤波通道都产生了红移现象,但是滤波通道的透射率保持100%不变。该研究结果可以为设计和制造高品质的光学滤波器件提供参考。

The optical filtering characteristics of four-element mirror symmetry structure photonic crystal(BCD)7A(DCB)7are studied by using transfer matrix method.The results show that photonic crystal(BCD)7A(DCB)7can a-chieve double-channel narrow-band optical filter,and the optical filtering characteristics are sensitive to the thickness of dielectric layer,but the responding mechanisms of different channels to the thickness of dielectric layer are differ-ent.For the shortwave channel,the quality factor of filter(Q)reduces with the increase of the thicknesses dB^dc^dD of dielectric layers B、C、D,and the effect of the dcon the Q is the most sensitive element,while the effect of dB is the weakest one.However,the Q increases quickly with the increase of the thickness dA of dielectric layers A.For the long wave channel,the Q increases quickly with the increase of the thickness dB^dD,and it grow faster with the increase of dD.The Q decreases with the increase of the thickness dA^dc.In addition,when the thicknesses of each dielectric lay-er increase,two channels of filter occur red shifting,but each filtering channer s optical transmittance keeps un-changed.The research results can provide a theoretical basis for the design of the new optical crystal filter and optical switch device.