Rotatable diffractive gratings based on hybrid-aligned cholesteric liquid crystals

Switchable Diffractive Cholesteric Gratings

Electrically switchable diffractive gratings based on cholesteric liquid crystals are suggested. An electric field switches the cholesteric cell between three states: two with a uniform in-plane director and one with a periodic in-plane director modulation. The modulated state produces a Raman–Nath diffractive effect. Characteristic time of switching is of the order of 10 ms. Diffractive proper...

Polymer-Stabilized Diffraction Gratings from Cholesteric Liquid Crystals

Switchable two-dimensional gratings based on field-induced layer undulations in cholesteric liquid crystals.

We propose switchable two-dimensional (2D) diffractive gratings with periodic refractive-index modulation arising from layer undulations in cholesteric liquid crystals. The cholesteric cell can be switched between two states: (1) flat layers of a planar cholesteric texture and (2) a square lattice of periodic director modulation associated with layer undulations that produces 2D diffraction pat...

Electrically-controlled two-dimensional gratings based on layers undulations in cholesteric liquid crystals

We developed electrically-switchable two-dimensional diffractive gratings with periodic refractive index modulation arising from layers undulations in cholesteric liquid crystal. Two-dimensional layer undulations occur above the threshold voltage when a planar cholesteric cell of thickness much larger than the cholesteric pitch is subjected to an electric field. The periodic structure of the la...

Fork gratings based on ferroelectric liquid crystals.

In this article, we disclose a fork grating (FG) based on the photo-aligned ferroelectric liquid crystal (FLC). The Digital Micro-mirror Device based system is used as a dynamic photomask to generated different holograms. Because of controlled anchoring energy, the photo alignment process offers optimal conditions for the multi-domain FLC alignment. Two different electro-optical modes namely DI...