title: New laser apparatus to measure oscillation amplitude down to picometer at megahertz frequencies.
abstract: A laser setup to study shear oscillations at small amplitudes with resonance frequencies up to 3 MHz is presented. The new approach combines gauging of the Gaussian laser beam and a lock-in amplifier. The device is tested with a 3 MHz AT-cut quartz crystal. The oscillation amplitude at the edge of the electrode on the quartz crystal is measured with a resolution of 2 pm.
authors.affiliation: Institute of Experimental Physics, Ulm University, 89069 Ulm, Germany.
authors.forename: F Z
authors.initials: FZ
authors.lastname: Zhang
authors.forename: S
authors.initials: S
authors.lastname: Walheim
authors.forename: T
authors.initials: T
authors.lastname: Schimmel
authors.forename: O
authors.initials: O
authors.lastname: Marti