Stretchable Blue Phase Liquid Crystal Lasers with Optical Stability Based on Small-Strain Nonlinear 3D Asymmetric Deformation

Abstract

Blue phase liquid crystal (BPLC) lasers exhibit exceptional optical quality and tunability to external stimuli, holding significant promise for innovative developments in the field of flexible optoelectronics. However, there remain challenges for BPLC elastomer (BPLCE) lasers in maintaining good optical stability during stretching and varying temperature conditions. In this work, a stretchable laser is developed based on a well-designed BPLCE with a combination of partially and fully crosslinked networks, which can output a single-peak laser under small deformation (44.429 nm lasing shift at 32% strain) and a broad-temperature range (from −20 to 100 °C). The superior performance can be attributed to the nonlinear 3D asymmetric deformation exhibited by the BPI lattice during stretching, particularly at low deformation rates below 40% strain, which effectively maintains the stability of the body-centered cubic structure (with the maximum strain of this BPLCE up to 220%). Moreover, the BPLCE exhibits excellent thermal stability over a temperature range from −180 to 70 °C with a stopband shift of less than ±10 nm. As a proof-of-concept, the application of BPLCE laser for morphology sensing and 3D mechanical perception is demonstrated, which paves the way for potential applications of flexible optoelectronics.