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This work investigates the controllability of the pretilt angle of liquid crystals (LCs) in a cell with an initial vertical alignment through microgrooves induced by the holographic fast-writing method. By changing the writing time or intensity of the pumped beam, the microgrooves with various surface modulations can form and provide distinct planar anchoring strength for the LCs. The pretilt angle of the LCs can be controlled over a range from 18.3? to 89?. The writing time of the microgrooves takes less than 25?s, which is a two-fold reduction in the time taken in previous investigations using other photoaligned methods.

This work proposes a viewing angle switching (VAS) panel using twisted-nematic liquid-crystals (TN-LCs). Calculations reveal that, in a low voltage regime, a TN-LC behaves optically as a high twisted (~90°) TN-LC in a vertical direction but as a low twisted (

The authors propose an experimental observation of the temperature-dependent coupling effect in a nematic liquid crystal (NLC) multiguide. A grating like electrode is fabricated with indium-tin-oxide in the NLC device. With the application of a voltage of 5.4 V, an optical multiguide structure is formed owing to the periodic orientation of liquid crystal molecules, induced by a grating like distributed electric field. A linearly polarized beam of 532 nm is launched into one certain channel and coupled to adjacent ones. Note that the coupling effect significantly depends on temperature. Additionally, we also observe a clear nonlinear light self-focusing phenomenon at a low light power of 15 µW.

holography technique involving various polarizations of excitation and probe beams has been employed to identify the strong asymmetry of excitation and diffraction in the guest-host system. In this paper, we report the temporal profiles of diffraction efficiency for transient gratings and their temperature and polarization dependences in azo-dye-doped liquid crystals. The dynamics of molecular reorientation phenomena in transient gratings is investigated by analyzing the buildup time of the diffraction maximum and diffractive decay. The study of the polarization dependence of the first-order diffraction efficiency and its corresponding temperature effect allows us to understand the underlying mechanism of laser-induced transient gratings. 2. Experimental