Title: Coherent control of flexural vibrations in dual-nanoweb fibers using phase-modulated two-frequency light,
Abstract: Coherent control of the resonant response in spatially extended
optomechanical structures is complicated by the fact that the optical drive is
affected by the back-action from the generated phonons. Here we report a new
approach to coherent control based on stimulated Raman-like scattering, in
which the optical pressure can remain unaffected by the induced vibrations even
in the regime of strong optomechanical interactions. We demonstrate
experimentally coherent control of flexural vibrations simultaneously along the
whole length of a dual-nanoweb fiber, by imprinting steps in the relative phase
between the components of a two-frequency pump signal,the beat frequency being
chosen to match a flexural resonance. Furthermore, sequential switching of the
relative phase at time intervals shorter than the lifetime of the vibrations
reduces their amplitude to a constant value that is fully adjustable by tuning
the phase-modulation depth and switching rate. The results may trigger new
developments in silicon photonics, since such coherent control uniquely
decouples the amplitude of optomechanical oscillations from power-dependent
thermal effects and nonlinear optical loss.