Ferroelectric Liquid Crystal Compound Lens Based on Pancharatnam–Berry Phase

Ying Ma,Vladimir G Chigrinov,Jianlin Zhao,Mingkui Yin,Hoi-Sing Kwok,Yuhang Shan

doi:10.3390/cryst12020231

Abstract

We report a ferroelectric liquid crystal (FLC) compound lens based on the Pancharatnam–Berry (PB) phase. The phase of the FLC compound lens is an integration of polarization grating and a PB lens. Thus, when light passes through an FLC compound lens, the output light’s polarization handedness will be changed accordingly. In this case, FLC compound lenses can function as concave/convex lenses with spatially separated output light and rapid transmittance tunability. The FLC compound lenses were fabricated using a single-step holographic exposure system, based on a spatial light modulator working as numerous phase retarders. Photosensitive azo-dye material was used as the aligning layer. The output light transmittance of the FLC compound lens can be operated at 150 μs. Our results achieve the potential applications on various displays and augmented reality.

Highlights

The lens, as one of the most important optical elements, is widely used in our daily life for optical usages, such as the eyeglass, camera objective, microscope and telescope [1].Compared with conventional refractive lenses, liquid crystal (LC) lenses show good potential, with the features of controllable birefringence and refractive indices, as well as high integration and compact size
The PB phase devices fabricated with liquid crystals (LCs) are potential candidates because of their inherent photoelectric properties, large optical birefringence and controllable continuous orientation [8,9]
Ferroelectric liquid crystals (FLCs) utilizing photo-alignment technology [16,18,19,20] represent a promising way to produce LC PB devices with a microsecond response [21], which is at least two orders of magnitude higher than common nematic liquid crystals

Summary

Introduction

The lens, as one of the most important optical elements, is widely used in our daily life for optical usages, such as the eyeglass, camera objective, microscope and telescope [1].Compared with conventional refractive lenses, liquid crystal (LC) lenses show good potential, with the features of controllable birefringence and refractive indices, as well as high integration and compact size. The PB phase devices fabricated with liquid crystals (LCs) are potential candidates because of their inherent photoelectric properties, large optical birefringence and controllable continuous orientation [8,9]. Several well-known optical elements use the PB phase, including the PB lens [10,11], polarization grating (PG) [12] and the q-plate [13]. They are widely used for the shaping of various wavefronts, such as a helical wavefront for vortex beams [9] and vector beams [14], as well as laser beam shaping [15]. A DMD (digital mirror device) [21,22,23,24] and direct laser writing [25,26,27]

Methods

Results

Conclusion