Multiple-Color Reflectors Using Bichiral Liquid Crystal Polymer Films and Their Applications in Liquid Crystal Displays.

Multiple-color reflectors using bichiral liquid crystal polymer films (BLCPFs) are investigated. The BLCPFs consist of alternate layers of two different single-pitch cholesteric liquid crystal (CLC) layers, named CLC#A and CLC#B. The thickness of each CLC layer equals its single pitch length.

Optical control of the rotation of cholesteric liquid crystal gratings.

Two photoalignment-based methods to achieve orientational control of optical diffractions by cholesteric liquid crystal (CLC) fingerprint gratings are proposed and demonstrated. A trace of methyl red in the CLC host can effectively induce surface alignment upon linearly polarized green exposure and enable optically rewritable alignment. An effective rotation of the photo-aligned CLC grating is attained by changing the surface alignment axis.

Optical manipulation of nematic colloids at the interfaces in azo-dye-doped liquid crystals.

This study demonstrates the optical manipulation of colloids dispersed in azo-dye-doped liquid crystals (DDLCs) where the accumulation occurs at the interfaces of the phase domains. We explain the mechanism related to the formation of the domains and the movement of the colloids in DDLCs with respect to the isomerization of azo-dye molecules via the illumination of laser beams. The colloids are dragged to the interfaces of the isotropic/nematic domain and the air bubble/isotropic domain by molecular interaction and Marangoni flows.

Fabrication of optical vortex lattices based on holographic polymer-dispersed liquid crystal films.

This Letter demonstrates optical vortex lattices based on holographic polymer-dispersed liquid crystal (HPDLC) films. The fabrication method uses a phase-only reflective spatial light modulator with numerically calculated phase profiles loaded on it to simplify multi-helical-wave interference. The beam profiles of the diffraction beams are simulated using the Fourier transform and compared with experimental results.

Complex beam shaping based on an equivalent q-plate system and analysis of its properties using digital holography polarization imaging.

In this study, we generate various complex beams carrying angular momentum (AM) by using a programmable beam shaping system to mimic typical q-plates. When a circularly polarized wave is incident onto the system, the emerging beam reverses its spin handedness and obtains a spatial phase factor. This phase factor can be engineered by designing a computer-generated hologram (CGH) and applying it to a spatial light modulator (SLM) to produce a beam with controllable spatially distributed orbital angular momentum (OAM) density.