Ring-focused light fields generated through a liquid-crystal module assisted by embedded aluminum concentric...

A new, to the best of our knowledge, liquid-crystal (LC) module based on an electrically driven and inducted formation of spatial electric fields in the LC micro-cavity for re-orienting LC molecules sealed, leading to a wavelike refractive index profile equivalent to traditional convex or concave ring-lenses, is proposed. The typical features of the LC module are a fine manipulation of light wave converging or diverging and a switching performance for regulating incident light waves according to the beam converging or diverging mode co-driven by a set of signal voltage applied over the top and bottom indium tin oxide (ITO) electrodes, and also the aluminum concentric cylinders (ACCs) embedded between the adjacent top circular ITO electrodes. The beam-diverging mode can be roughly simulated by an intermediate LC structure without any ACC. The electric fields generated in the LC micro-cavity can be obviously concentrated by the charged ACC through inducted net positive or negative charges over both ends or only one end immersed in the LC film. This work has laid a solid foundation for developing a new type of dual-mode LC ring-lenses driven electrically.