Visible Topological Lasing Based on a Polymer-cholesteric Liquid Crystal Superlattice

Low-threshold topological lasing at visible wavelengths and with circular polarizations is demonstrated theoretically, and experimentally in a femtosecond-laser-written micron-sized polymer-cholesteric liquid crystal composite structure by manipulating the topological mini-bands based on the Su-Schrieffer-Heeger model.