Colloquiums INC 2019: Visualization of spatial modulation and persistent response states of strongly-driven membrane resonators

Title:  Visualization of spatial modulation and persistent response states of  strongly-driven membrane resonators

25 March,  12h30

Sala de Conferencias, Módulo 00, Facultad de Ciencias, UAM

Abstract:

Visualization of spatial modulation and persistent response states of
strongly-driven membrane resonators

Elke Scheer, Fan Yang, Felix Rochau, Jana Huber, Alexandre Brieussel, Gianluca Rastelli, Eva M. Weig

1Department of Physics, University of Konstanz, 78457 Konstanz, Germany

Micro- and nano-scale mechanical resonators operated in the nonlinear regime exhibit unusual dynamic behavior, e.g. the phenomenon of persistent response, which denotes the development of a vibrating state with nearly constant and high amplitude over a wide frequency range, see Fig. 1 left. So far, the requirements and the underlying mechanism to obtain the persistent response state have been unclear, mainly because of the difficulties to characterize this complex vibrational state experimentally. Here we present a method based on optical interferometry to directly image the vibrational state of membrane resonators. We show that upon increasing the driving strength the membrane first adopts a deflection pattern determined by localized, ring-shaped overtones of the driven mode (Fig. 1 middle) and that we denote as spatial modulation. At even larger driving strength, the persistent response arises as a signature of mode coupling between different flexural modes and their localized overtones, see Fig. 1 right.