Ultrafast electro-optic switching in liquid crystals

We present the nanosecond electro-optic response of liquid crystals in the nematic and isotropic phases. The results demonstrate that in the isotropic phase (close to the phase transition), both the dielectrically positive and negative liquid crystals have larger field induced birefringence than in the nematic phase. However, a nematic mixture with negative dielectric anisotropy exhibits two advantages, namely, the field induced birefringence is weakly dependent on temperature, and the characteristic time of this nanosecond response does not depend on the electric field. The observed nanosecond response can benefit the ultrafast electro-optic applications.