Feedback Control and Characterization of a Microcantilever Using Optical Radiation Pressure

摘要

We describe a method for feedback-regulation of a microcantilever's responseusing optical radiation pressure. One laser measures the position of thecantilever and another laser applies a force that is a phase-shifted functionof that position. The force is due solely to the momentum of the photons in thelaser. The feedback changes the microcantilever's effective quality factor Qeffand effective temperature Teff. Reduction of both Qeff and Teff by more than afactor of 15 is demonstrated. Additionally, we suggest a method fordetermination of a microcantilever's spring constant using the known forceexerted on it by radiation pressure.