Stuttgart 2012 – wissenschaftliches Programm
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Q: Fachverband Quantenoptik und Photonik
Q 6: Mikromechanische Systeme
Q 6.5: Vortrag
Montag, 12. März 2012, 11:30–11:45, V7.02
A versatile scheme for read-out and actuation of nanomechanical motion using silica microspheres — •Leonhard Neuhaus1, Emmanuel van Brackel1, Emanuel Gavartin1, Pierre Verlot1, and Tobias Kippenberg1,2 — 1Ecole Polythechnique Federale Lausanne, CH-1015 Lausanne, Schweiz — 2Max-Planck-Institut für Quantenoptik, Hans Kopfermann Strasse 1, 85748 Garching, Deutschland
Opto-nanomechanical systems serve as exceptional force transducers due to an ultra-low mass and high mechanical quality factors combined with enhanced readout via a high-finesse-optical microcavity. We report readout and actuaction of nanomechanical Si3N4-oscillators using evanescent coupling to ultrahigh optical-Q silica microspheres. Compared to earlier work, we have significantly enhanced optomechanical coupling rates and the intracavity power due to the use of a superior microcavity. This enables the observation of dynamical backaction cooling rates up to 8 kHz. We were also able to use this setup to probe different types of oscillators, such as niobium-coated strings or few-layer graphene sheets. We counteract a limitation of optomechanical coupling rates resulting from the parametric instabiliy by an external feedback loop with radiation-pressure actuation. Our setup could prove useful to a number of experiments requiring the ultra-sensitive detection of nanomechanical motion, while the higher accessible powers due to feedback-stabilization will likely permit the observation of fundamental effects of quantum backaction in the future.