Laser etchings on polyimide alignment layers in multi-domain VA mode

Abstract

We used a homeotropic and homogeneous hybrid double layer with micro-domains as a vertically aligned (VA) mode for wide viewing angle. Multi-domains of homogeneous polyimide on homeotropic polyimide (PI) layer were obtained using a noncontact method based on laser ablation. Nonpolarized light from a KrF excimer laser at 248 run was illuminated through a phase mask to etch gratings of various patterns onto homeotropic PI layer. The contrast of LC cells, made with the hybrid double layer, along the direction of 45degrees to one the polarizers, was about 10:1 up to +/- 30degrees without any compensation film.