Coherent elastic waves in a one-dimensional polymer hypersonic crystal

摘要

Using the methods of picosecond acoustics, we inject high amplitude hypersonic wavepackets into a polymer superlattice and optically detect the propagating coherent elastic waves. The spectrum of the optically detected signal shows the elastic modes typical for folded phonon dispersion curves. The experimental results and related modeling show the feasibility of using polymer one-dimensional hypersonic crystals as acoustic devices in the gigahertz frequency range.