A polarized bifocal switch based on liquid crystals operated electrically and optically

摘要

A polarized bifocal switch based on liquid crystals (LC) operated electrically and optically is demonstrated. The bifocal switch mainly consists of two parts: a LC layer as a polarization switch and two polymeric layers for modulation of polarization dependent spatial phase difference which results in a positive or a negative lensing effect. The orientations of the LC molecules in the polarization switch are manipulated either in electrically switching (ES) mode or optically rewritten (ORW) mode. The bifocal switch with an aperture size of 10 mm exhibits two discrete lens powers (-1.39 Diopter and +0.7 Diopter) with different polarization states no matter in ES mode or in ORW mode. ORW mode is also a bistable mode. The related mechanism and electro-optical performance are discussed and demonstrated. Such a versatile optical switch is capable of not only switching between a positive lens power and a negative lens power, but also switching between two linear polarization states which can be useful in optical systems. The potential applications are for optical systems, wearable devices and ophthalmic lenses.