New laser apparatus to measure oscillation amplitude down to picometer at megahertz frequencies.
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.
Zhang
F Z
FZ
Institute of Experimental Physics, Ulm University, 89069 Ulm, Germany.
Walheim
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Schimmel
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Marti
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