Azo Molecular Glass Patterning from Chiral Submicron Pillar Array to Self‐Organized Topographic Transition via Irradiation with Circularly Polarized Light

Abstract

AbstractThis work reports chiral structure formation and self‐organized surface patterning upon submicron pillar arrays of an azo molecular glass, induced by irradiation with a circularly polarized laser beam at 488 nm. After the irradiation for 2–3 min, the chiral spiral structures form on the wall of every pillar in the hexagonal array. The spiral direction induced by the right‐handed circularly polarized light is mirror‐symmetrical to that caused by the left‐handed circularly polarized light. Upon further irradiation and gradual erasure of the original pillars, which is caused by mass transfer along the electric vibration direction of the circularly polarized light, a new set of pillars emerges through splitting every original pillar into four equivalent pillars with smaller size. A series of the well‐organized surface patterns appear in the intermediate stage of the topographical transition process. In the final stage, the highly regular pillar array with quadruple area density is formed and stabilized. The structure formation and self‐organized topographic transition are thoroughly investigated by experiments and optical simulation. These intriguing observations are found to be correlated with several unique light–matter interaction effects. The discoveries can provide a new approach to create hierarchical surface patterns and detect the handedness of light.