Two-dimensional liquid crystal polarization grating via linearly polarized light modified multi-beam polarization interferometry

Holographic lithography is widely used as an effective approach for twodimensional (2D) photonic crystal fabrication. However, for the fabrication of 2D polarization structures based on photoaligied liquid crystals (LCs), holographic lithography method is limited. The fabrication requires full coverage of light intensity, 2D chiral distribution and continuously varying polarization direction, which could be hardly guaranteed by multi-beam interference of circularly polarized light (CPL). Herein, we introduce a linearly polarized light (LPL) into a three-CPL interference configuration to improve the interference field and fulfill the critical requirement. The introduced LPL intensity is chosen to be 1/5 of the CPL to guarantee both full coverage of light intensity and well photoalignment defined LC directors. Moreover, the introduction of the weak LPL into multiple CPL interference is shown to give little disturbance to the desired diffraction properties. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement