Developing a novel 2D electro-optic scanner for potential micro display and head mounted display application

The goal of the present work is to create a miniature 2D light scanning device without any moving parts using integrated electro-optic (EO) liquid crystal (LC) material. The design is based on changing the propagation direction of a light beam when it is incident to an electro-optic medium with a voltage-controlled index of refraction. To achieve 2D beam steering and scanning, the device is designed in two stages. For horizontal beam steering, a LC prism (thickness = 10 μm) created between two glasses is used to deflect beam by refraction due to change in refractive index of LC. For vertical beam steering, a virtual prism is created between two glasses by offsetting top and bottom electrodes. When an electric field is applied to the electrodes, LC directors create a virtual prism due to physical offset between top and bottom electrodes help to achieve beam deflection in vertical direction. In this work, a simulation study is conducted on the proposed design to achieve 2D deflection of laser beam (λ=632 nm). According to Snell's law, theoretically, a maximum horizontal deflection of 10.52° is achieved at a prism angle, and incident angle of 66.1° and 21.99° respectively. Whereas through a simulation study, maximum horizontal deflection of 34° and maximum vertical deflection of 13° is achieved at given incident angle. This low-cost and lightweight optical scanner can fit inside a tube with a diameter of less than 5 mm and can be implemented for augmented reality (AR), virtual reality (VR), or standalone microdisplay applications.