Anisotropy of the electro-optic Kerr effect in polymer-stabilized blue phases

Liquid crystalline polymer stabilized blue phases (PSBPs) are candidate materials for next generation electrooptic switching devices because they form a self-organized three-dimensional periodic structure and exhibit a fast response time of submillisecond order. Considering the crystallographic structures of PSBPs, it is intuitive to believe that the electro-optic effect would depend on the direction of the applied electric field; however, this relationship has not yet been investigated. In this study, we prepared two kinds of samples in which the (110) and (200) planes were oriented parallel to the substrates, and investigated the electro-optic Kerr effect as a field was applied between the two substrates. The two samples exhibited differing behaviors, with the Kerr coefficient of the (110)-oriented sample being larger by 20% than that of the (200)-oriented sample. These results imply that the electro-optic Kerr effect of PSBPs is not isotropic but anisotropic, just like cubic optical crystals.