Broadband Mechanically Tunable Metasurface Reflectivity Modulator in the Visible Spectrum

Abstract

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.

Emulating paper: a review of reflective display technologies

“…For instance, preliminary research into tunable metasurfaces has revealed potential pathways for achieving broadband tunability in the visible spectrum with displacements of a mere 150 nm. 91 Furthermore, graphene-based IMODs have demonstrated remarkable capabilities, achieving refresh rates of up to 400 Hz and ultra-high resolution. 87 The landscape of reflective display technologies, diverse and evolving, stands out for its unique advantages in the broader spectrum of display technologies.…”

“…Recently, an MEMS-based actively tunable metasurface was shown to be able to modulate the reflectivity in the visible spectrum. 91 The working principles and a microscope image of a segmented display prototype are shown in Fig. 17.…”