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Electrically Tunable Multicolored Filter Using Birefringent Plasmonic Resonators and Liquid Crystals
journal contribution
posted on 2020-01-10, 11:29 authored by Luc Driencourt, François Federspiel, Dimitrios Kazazis, Li-Ting Tseng, Richard Frantz, Yasin Ekinci, Rolando Ferrini, Benjamin GallinetDynamic
tuning of color filters finds numerous applications including
displays or image sensors. Plasmonic resonators are subwavelength
nanostructures which can tailor the phase, polarization, and amplitude
of the optical field, but they are limited in color vibrancy when
used as filters. In this work, birefringence-induced colors of plasmonic
resonators and a fast switching thin liquid crystal cell are combined
in a multicolored electrically tunable filter. With this mechanism,
the color gamut of the plasmonic surface and the liquid crystal cell
is mutually enhanced in order to generate all primary additive and
subtractive colors with high saturation as well as different tones
of white. A single filter is able to cover more than 70% of the color
gamut of standard RGB filters by applying a voltage ranging between
2 and 6.5 V. This spectral selectivity is added in transmission without
any loss in the image resolution. The presented approach is foreseen
to be implemented in a variety of devices including miniature sensors
or smart-phone cameras to enhance the color information, ultraflat
multispectral imagers, wearable or head-worn displays, as well as
high resolution display panels.