Competition between anchoring and reversible photo-induced alignment of a nematic liquid crystal

Photoactive Fluorinated Poly(azomethine)s with Azo Groups in the Main Chain for Optical Storage Applications and Controlling Liquid Crystal Orientation

“…The writing–erasing process can be obtained for a number of cycles and for different recording wavelengths which indicates the diffusion mechanism of photoinduced anisotropy in the Azo-Pam . By use of cross-linking and photodegradation mechanisms, the writing and erasing capabilities of the photosensitive film are strongly limited. , Finally, when the both beams are turned off, the remaining anisotropy continues to hold at a certain value. We assume that the main reason for residual anisotropy is the significant intermolecular interaction of macromolecules, which partially fixes (stabilize) the cis -stationary state of azobenzene fragments in the polymer.…”

Photoalignment of Liquid Crystals: Applications to Fast Response Ferroelectric Liquid Crystals and Rewritable Photonic Devices

“…The alignment induced on a nematic LC by a photoaligned polymer film with azo-dye side groups was investigated. 19 The orientation of the LC molecules was manipulated in a reversible manner by irradiating the film with a polarized light. The reversibility of the photoinduced alignment may allow the recording and erasing of information in a LC display.…”

15.1: Optically Rewritable LiquidCrystal Technology: A New Green EPaper Approach

“…Photoswitchable bistable reflective liquid crystal display based on an azo-dye doped LC film was successfully demonstrated by Lin et al [8] (a dye-adsorbed polymer film with a writing beam intensity of 150 mW/cm 2 yielded a writing time of 60 s). The alignment induced on a nematic LC by a photoaligned polymer film with azo-dye side groups was investigated [9]. The orientation of the LC molecules was be manipulated in a reversible manner by irradiating the film with a polarized light.…”

“…The works mentioned above [5][6][7][8][9] have some limitations for the writing and erasing capabilities. The reversible writing-erasing process can be obtained only by the rotation molecules photoalignment in solid films observed in azo-dye layers, pioneered by us such as sulfonic azo-dye SD1 [10][11][12][13].…”