title: Time-resolved gigahertz acoustic wave imaging at arbitrary frequencies.
abstract: We describe a way to generate and detect arbitrary frequency components in time-resolved surface acoustic wave imaging based on optical pumping and probing with a periodic light source. The detailed theory of the technique, based on beam modulation and Fourier analysis, for a variety of possible experimental configurations is presented, followed by experimental data for a glass substrate covered with a thin gold film. We show how the acoustic dispersion relation can be obtained to arbitrary frequency resolution, not limited by the laser pulse repetition rate.
authors.forename: Osamu
authors.initials: O
authors.lastname: Matsuda
authors.forename: Shogo
authors.initials: S
authors.lastname: Kaneko
authors.forename: Oliver B
authors.initials: OB
authors.lastname: Wright
authors.forename: Motonobu
authors.initials: M
authors.lastname: Tomoda