Acoustic notch filter based on self-collimation sonic crystals

Abstract Utilizing the self-collimation effect in two-dimensional (2D) sonic crystals (SCs), we have proposed an acoustic notch filter which is composed of two perfect mirrors and a beam splitter. Numerical simulation shows that by properly designing the inside structure of the 2D SC, the self-collimated acoustic waves with a desired frequency can be trapped between the two mirrors, realizing the notch filtering function. Moreover, the frequency and bandwidth of the notch filter can be arbitrarily adjusted by changing the parameters of the internel structure, in a considerably broad band. Potential applications include acoustic communication and acoustic signal processing, especially for underwater circumstances.