Structured Optical Materials Controlled by Light

TL;DR

This paper demonstrates a novel method to control the optical response of structured materials using light-induced elastic reshaping, enabling fast, reversible optical beam steering in liquid crystalline networks.

Contribution

It introduces a light-driven, reversible deformation technique for tuning optical properties of structured materials, demonstrated with a fast, optically controlled beam steering device.

Findings

Achieved sub-millisecond response time for optical beam steering.

Validated the approach with finite-element modeling of actuation dynamics.

Demonstrated reversible shape change controlled by light in liquid crystalline networks.

Abstract

Materials of which the optical response is determined by their structure are of much interest both for their fundamental properties and applications. Examples range from simple gratings to photonic crystals. Obtaining control over the optical properties is of crucial importance in this context, and it is often attempted by electro-optical effect or by using magnetic fields. In this paper, we introduce the use of light to switch and tune the optical response of a structured material, exploiting a physical deformation induced by light itself. In this new strategy, light drives an elastic reshaping, which leads to different spectral properties and hence to a change in the optical response. This is made possible by the use of liquid crystalline networks structured by Direct Laser Writing. As a proof of concept, a grating structure with sub-millisecond time-response is demonstrated for optical beam steering exploiting an optically induced reversible shape-change. Experimental observations are combined with finite-element modeling to understand the actuation process dynamics and to obtain information on how to tune the time and the power response of this technology. This optical beam steerer serves as an example for achieving full optical control of light in broad range of structured optical materials.