相位失配弹性平板复合波导中的缺陷态

Defect states in elastic plate waveguides induced by phase mismatch

为了在弹性波波导中实现缺陷态的调控,该文基于相位失配原理设计了一种周期性平板波导结构。以正弦边界弹性波导为例,通过连接具有不同相位的两段波导结构,形成了弹性板中不同程度的缺陷,并分析了其谱带特性和能量局域化特征。结果表明,禁带中存在两个不同模式的缺陷态,其以透射峰形式出现并随着相位的改变产生频移。与此同时,两个缺陷态在空间上对应的应力场和位移场分布也具有不同的模态特征。该文提出的复合弹性波导缺陷态调控方法,不仅为研究弹性波与结构之间的内在联系提供了关键的理论支持,也为实际弹性波探测器件的设计提供重要参考。

In order to control defect states in elastic waveguides,a periodic flat waveguide structure is designed based on the phase mismatch principle.Taking the elastic waveguide with sine boundaries as an example,by connecting two waveguides with different phases,different degrees of defects are formed in the elastic plate,and its spectral band characteristics and energy localization characteristics are analyzed.The results show that there are two defect states with different modes in the band gap,which appear in the form of transmission peaks and produce the frequency shift with the change of phase.At the same time,the distribution of stress and displacement fields corresponding to the two defect states in the space domain also have different modal characteristics.In this paper,the study of regulating characteristics in composite waveguides provides the theoretical support for establishing the internal relationship between elastic waves and structures,which provides the essential references for practical elastic wave detector design.