posted on 2019-05-07, 00:00authored byChengjun Zou, Andrei Komar, Stefan Fasold, Justus Bohn, Alexander A. Muravsky, Anatoli A. Murauski, Thomas Pertsch, Dragomir N. Neshev, Isabelle Staude
Tunable
dielectric metasurfaces able to manipulate visible light
with high efficiency are promising for applications in displays, reconfigurable
optical components, beam steering, and spatial light modulation. Infiltration
of dielectric metasurfaces with nematic liquid crystals (LCs) is an
attractive tuning approach, which is highly compatible with existing
industrial platforms for optical and electronic devices. Here, we
demonstrate electrically tunable transparent displays based on nematic
LC-infiltrated tunable dielectric metasurfaces at visible frequencies.
Importantly, the technique of photoalignment of LCs is adopted to
improve the LC prealignment quality and thus the tuning accuracy and
contrast in the visible. By applying a voltage across the infiltrated
metasurface cell, we observe resonance shifts that are more than twice
larger than their line width. We track the spectral shifts of the
electric and magnetic dipole resonances as they move into and out
of the so-called Huygens’ regime of high transparency originating
from spectrally overlapping electric and magnetic dipole resonances.
Furthermore, we realize a switchable metasurface display with a measured
modulation depth of 53% at 669 nm operation wavelength for an applied
voltage of 20 V. The novel LC tuning platform demonstrated in our
work may lead to the development of next-generation LC display devices
that are able to overcome current limitations of minimal pixel size
and speed of operation.