Reflectivity modulation is a critical feature for applications
in telecommunications, 3D imaging and printing, advanced laser machining,
or portable displays. Tunable metasurfaces have recently emerged as
a promising implementation for miniaturized and high-performance tunable
optical components. Commonly, metasurface response tuning is achieved
by electro-optical effects. In this work, we demonstrate reflectivity
modulation based on a nanostructured, mechanically tunable, metasurface,
consisting of an amorphous silicon nanopillar array and a suspended
amorphous silicon membrane with integrated electrostatic actuators.
With a membrane displacement of only 150 nm, we demonstrate reflectivity
modulation by Mie resonance enhanced absorption in the pillar array,
leading to a reflectivity contrast ratio of 1:3 over the spectral
range from 400–530 nm. With fast, low-power electrostatic actuation
and a broadband response in the visible spectrum, this mechanically
tunable metasurface reflectivity modulator could enable high frame
rate dynamic reflective displays.