High frequency one-dimensional phononic crystal characterized with a picosecond transient grating photoacoustic technique

Periodic patterns of relief defined on a substrate using conventional lithographic techniques are phononic crystals for surface localized acoustic waves. Picosecond transient grating characterization of the acoustic behavior of Rayleigh waves in structures of binary, one-dimensional patterns of relief with feature sizes of a few microns show that these crystals exhibit complete phononic band gaps at frequencies of a few tenths of a gigahertz. These types of structures could be useful for applications in surface acoustic wave devices; understanding their acoustic behavior will help to establish strategies for transient grating examination of complex microstructures.