声子晶体的研究进展及应用前景

Progress in researches of phononic crystal and the application perspectives

声子晶体是近10年来提出的一类概念、声学材料,这种周期性结构所具有的声波带隙特性可以认为具有某种过滤效应,即当多种频率的振动或声波通过此类晶体时,由于布拉格散射,便会分裂为导带和禁带,处于禁带频率范围内的振动或声波将被禁止在晶体中传播,而处于导带频率范围内的振动或声波则能顺利通过声子晶体。通过求解声波在晶体中的波动方程可以设计所需要的声子禁带和导带。文中对声子晶体的概念和基本特征、研究进展、理论方法、潜在应用等方面进行了阐述,并对声子晶体的研究工作进行了展望。

Phononic crystals are conception and acoustic materials appeared ten years ago. This kind of periodical structure can be considered as having the function of filtration, i.e., the crystal breaks into pass-bands and band-gaps due to Prague scatter when vibration or sound with multiple frequencies is transmitted through it. Propagation of vibration and sound in the band-gap is not allowed. On the contrary, other frequency components can pass the crystal freely. Positions of band-gaps and pass-bands can be engineered by evaluating the acoustic wave equations in the crystals. In addition, existence of the band-gaps is closely associated with the Anderson localization of phonons in inhomogeneous media. The concepts, basic features, development, theoretical methods, and potential applications are discussed.