Multiple degrees‐of‐freedom programmable soft‐matter‐photonics: Configuration, manipulation, and advanced applications

Abstract

For centuries, humans have never stopped exploring the nature of light and manipulating it, since light carries multiple information through its intrinsic wave‐particle dualism, including wavelength, amplitude, phase, polarization, spin/orbital angular momentum, etc., which determines the physical language and basic manners we perceive the objective world. Conventional optical devices, such as lenses, prisms, and lasers, are composed of solid elements that are bulky, making it difficult to manipulate light dynamically with multiple degrees‐of‐freedom. Comparatively, some responsive soft matters, especially represented by liquid crystals (LCs), possess distinctive orientational order and spontaneous self‐assembled superstructures, enabling the digital programming of microstructures and multiple degrees‐of‐freedom manipulation of their optical characteristics. The optical manipulation based on these soft superstructures, that is, the “soft‐matter‐photonics”, is playing an impressive role in integrated functional devices, especially in the present age of information explosion. Herein, we review the latest advances, respectively, in the microstructure configurations, multiple degrees‐of‐freedom manipulations, and the relevant prospective applications. Additionally, scientific issues and technical challenges that hinder the programing operation and optical manipulations are discussed. Toward a four‐dimensional optical manipulation of soft condensed matter, this review may have wide implications on a variety of applications, including the integrated fabrication of compact elements, multi‐channel information processing and high‐capacity optical communications.