Polymer-Stabilized Monodomain Blue Phase Diffraction Grating

The structural beauty of liquid crystalline blue phases is attested not only by their colorful optical micrographic textures but also by optical isotropy. More importantly, the homogeneity of the structures influences greatly to the electro-optic properties. In this work, how the lattice orientation in polymer-stabilized blue phase liquid crystal (PS-BPLC) diffraction grating affects phase-modulated diffraction efficiency is elaborated. A well-arranged monodomain structure of blue phase is achieved and its diffraction capability is compared with multidomain PS-BPLC. The diffraction efficiency in the zeroth order of monodomain PS-BPLC is improved by 9% compared to that of multidomain structure. In addition, both driving and threshold voltages in monodomain PS-BPLC are decreased by 29% and 30%, respectively, compared to those in multidomain PS-BPLC owing to the regular arrangement of cubic lattices that give rise to increase in the coherence length and unified response in molecular reorientation under electric fields. Furthermore, the monodomain PS-BPLC shows an efficient polarization conversion of linear polarization into circular polarization. It is believed that the device exhibits great potential to be used as a polarization converter or beam steering devices.