Focusing of sound in a 3D phononic crystal
Focusing of sound in a 3D phononic crystal
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DOI：
10.1103/physrevlett.93.024301
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发表时间：
2004-07-09
影响因子：
8.6
通讯作者：
Sheng, P
中科院分区：
文献类型：
--
作者：
Yang, SX;Page, JH;Sheng, P
本文对三维声子晶体中全带隙以上通带中的声子聚焦现象进行了实验和理论研究。波的传播与频率和入射方向都有很大关系。这种传播各向异性导致了非常大的负折射，这可以用来将发散的超声光束聚焦成一个焦深较大的窄焦斑。利用傅里叶成像技术，基于多重散射理论计算的三维频率面，很好地解释了实验场模式。
We present a combined experimental and theoretical study of phonon focusing phenomena in a pass band above the complete band gap in a 3D phononic crystal. Wave propagation was found to depend dramatically on both frequency and incident direction. This propagation anisotropy leads to very large negative refraction, which can be used to focus a diverging ultrasonic beam into a narrow focal spot with a large focal depth. The experimental field patterns are well explained using a Fourier imaging technique, based on the 3D equifrequency surfaces calculated from multiple scattering theory.