Electro-optical switching of the holographic polymer-dispersed liquid crystal diffraction gratings

Abstract

Polymer-dispersed liquid crystal (PDLC) is a material promising for application in optical communications, diffractive optics and optical data storage. Diffraction gratings were optically recorded in a novel PDLC material developed at the Centre for Industrial and Engineering Optics. Details of the fabrication and preliminary results of electro-optical switching of the holographic PDLC (HPDLC) diffraction gratings are presented. The redistribution of LCs was observed by using phase contrast microscopy and confocal Raman spectroscopy.

Characterization of liquid crystals impregnated micrometric diffraction gratings for an active near-IR light extraction control

“…The holographic pattern fixes the LCs in place by polymerization, while the non-insulated parts are still mobile while the other part is still mobile. The resulting diffraction grating is electrically switchable (Margerum et al 1992;Pavani et al 2009;Caputo et al 2004).…”

Advancements and Applications of Liquid Crystal/Polymer Composite Films

“…Reflective HPDLC gratings can be switched between selective reflection and transmission modes. HPDLC grating has been widely studied and applied in fiber-optical switches and other fields due to its remarkable optical control characteristics. , …”

“…HPDLC grating has been widely studied and applied in fiber-optical switches and other fields due to its remarkable optical control characteristics. 23,24 Nematic LCs (NLCs) such as cyanobiphenyls are the most common type of LCs employed in PDLCs, while other LC materials including smectic LCs, cholesteric LCs, and discotic LCs are utilized under certain conditions to obtain obvious optical properties. Taking a polymer-dispersed cholesteric liquid crystal (PDCLC) film as an example, 12 without an electric field, the PDCLC film scatters light (Figure 2c), but by the application of an electric field, the film becomes transparent (Figure 2d).…”