Liquid Crystal Beam Steering Components for Efficient Light Steering

Problem Definition:

Smart micro-optical components are emerging  in many novel applications, such as stage lightings with tunable directions, micro lens with multiple focus lengths in camera and sun light collectors and so forth (Fig.1). Liquid crystal has a large birefringence which is controllable with an electric field above the threshold. Liquid crystal combined with the micro-prism structures or the interdigital ITO electrodes could realize the switchable and efficient beam steering property. With specially designed passive components with adequate optical magnifications, applied to the aforementioned liquid crystal beam steering device, a larger steering angle could be also achievable.


    

        (a)(b)



(a)                                                                                       (b)

Fig.1 LC beam steering compopnents: (a) Proposed LC beam steering device with optical magnifying component; (b) Applications of the proposed LC beam steering components: from left to right, eye-steering backlight for efficient & advanced 3D displays, efficient luminaries with adjustable light distribution, efficient sun light collectors without mechanical moving parts.


Objectives:

In this study, two approaches are adopted to fabricate the liquid crystal beam steering components: liquid crystal combined with the micro-prism structures and liquid crystal beam steering device based on the gradient refractive index (GRIN) effect. To improve the steering angle, some passive components with adequate optical magnifications will be combined with the single LC device; and some special liquid crystal materials (dual frequency LCs, blue phase LCs) will be also applied to the component to improve the response time; Optical characterizations will be studied in detail with different driving schemes. At last, those successful components will be used as demonstrators for the SECONDOS project.


Keywords:

Liquid crystal beam steering devices, dual frequency/blue phase liquid crystal, light steering.

Location:

Ardoyen CMST + at home.