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Dr. Warner Venstra

Delft University of Technology

Thursday, July 4th, 2013 at 03:00:00 PM  

Conference room Querzoli - LENS - via Nello Carrara 1 - Sesto Fiorentino (Florence)

Published on-line at 06:31:33 PM on Thursday, June 20th, 2013

Noise and nonlinearity in micro- and nanometer scale mechanical resonators

Origin of nonlinearity in the singly-clamped cantilever and the clamped-clamped bridge.

Micro- and nanometer scale mechanical devices are extremely susceptible to external forces, which leads to a high thermomechanical noise floor and an early onset of nonlinear behaviour. I will discuss origins of nonlinearity in two exemplary device geometries: the singly-clamped cantilever and the clamped-clamped bridge. We demonstrate that, in a cantilever vibrating in the nonlinear regime, a fluctuating environment can be exploited to enhance the signal-to-noise ratio.

Nonlinearity also gives rise to coupling between the vibration modes, which opens the possibility to deploy cavity-based transduction schemes in a single mechanical resonator. In micro- and nanometer scale devices this coupling is significant, and it enables modification of the dynamic range and Q-factor control via modulation at the mechanical sideband frequencies. Ultimately, the mode coupling impose a limit on the experimentally observed Q-factors at finite temperature.

For further informations, please contact Prof. Francesco Marin.