Experimental Studies on Sonic-Crystal Defect-Mode Waveguides Composed of a Periodic Chain of Single-Defects

单缺陷周期链组成的声晶体缺陷模波导的实验研究

基本信息

批准号：
18360176
负责人：
MIYASHITA Toyokatsu
金额：
$ 5.82万
依托单位：
Ryukoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

项目摘要

We have obtained the following results according to the purpose and plan of the research described in the application documents. In this report, a waveguide composed of a periodic chain of single-defects, or point-defects, are called a defect-mode waveguide.(1) Two methods to analyze the temporal and frequency characteristics of defects in an artificial crystal, namely, an internal excitation method which investigates them by exciting impulse, or burst sound pressure in a defect, and an external method by an excitation of a defect from the outside of the crystal.(2) Spatial confinement and frequency characteristics of a single-defect, or point-defect, embedded in a sonic crystal are investigated by both the external and internal methods, and the theoretical and experimental results had a good coincidence.(3) Temporal responses and frequency characteristics of two adjacent single-defects, which compose elementary parts of defect-mode waveguides, are investigated by FDTD simulations of t … More he wave propagation, by experimental external excitation method and by a coupled-mode theory. Well quantitatively agreed results indicated validity of the three methods.(4) Straight waveguides with and without a sharp bend composed of a chain of single defects proved to have a good 100% transmission in the pass-band by means of a FDTD simulation and an experimental external excitation.(5) Transmission characteristics of long defect-mode waveguides, which have a sharp bend and a branch or a crossroads, were measured by the ultrasonic waves of a frequency of 20〜40 kHz in air. The following items were confirmed, namely their high transmission per lattice constant in the pass band, and a high suppression in the forbidden band outside the pass band, and a good branching characteristics.(6) A high 50% mode coupling was obtained between a straight defect-mode waveguide and a neighboring defect-mode waveguide which has a sharp bend to remove from the former waveguide.(7) We have established a new coupled-mode theory which describes the behaviors of an arbitrary number of coupled modes of a chain of defect-modes. Quantitative preciseness of the results deduced by this theory was confirmed by the FDTD simulation and the experimental results described above. Less

我们已经在应用文档中所描述的研究的目的和计划。人造晶体中缺陷的频率通过令人兴奋的冲动来研究它们，或者在缺陷中爆发声压，而外部方法是通过外部和内部方法和外部进行的兴奋。理论和实验性的TID具有良好的巧合。通过FDTD（5）长缺陷模式波导或十字路口的传播特性，必须通过频率的FDTD（5）传播特性，必须在传球频段中具有良好的100％传输，以通过频率的超声波来测量单个缺陷项目的链条。空气中的20-40 kHz被确认，即它们的较高的传输有些良好的分支特征。 FDTD仿真和实验结果较少的bove量证实了缺陷模型的数量