ネマティック自由表面膜における光誘起回転運動

抄録

We demonstrate a circular flow formation at a surface in homeotropically oriented nematic liquid crystals with a free surface by a focused laser beam irradiation. Under a weak laser power, a pit together with an associated circular bulge is formed; the Marangoni effect. Here a diverging molecular flow from the pit (thermocapillary flow) also induces the director tilt to the radial direction. With increasing the laser power, the pit becomes deeper, and eventually evolves to a circular flow associated with a deeper pit and subsidiary circular bulge or valley structures. This phenomenon is induced by escaping from excess deformation energy due to a bend deformation of the director.