Tunable Chiral Photonic Defect Modes in Locally Polymerized Cholesteric Liquid Crystals

摘要

A structural defect is introduced in the helical periodic lattice of a cholesteric liquid crystal, a well-known pseudo one-dimensional photonic band-gap material. The method utilizes an ultra-fast pulse laser to induce two-photon polymerization in a photo-polymerizable cholesteric liquid crystal material to directly fabricate regions with different pitch lengths. Single or multiple defect modes were exhibited in the selective reflection band of the cholesteric liquid crystal, depending on the fabrication conditions of the defect structure. Optically pumped laser-action experiments showed that lasing from the single defect-mode had the smallest threshold compared to other lasing modes.