Creation of artificial optical response, which is determined by the materials geometry rather than chemical composition, is one of the main challenges of modern physics. In this paper application of large-area chiral excimer laser patterning for the creation of artificial chirality is described. Polymethylmethacrylate was doped with chromophore (Fast Red ITR) and this film was irradiated with circularly polarized KrF excimer laser beam. Surface morphology of pristine and treated samples was studied by confocaland AFM microscopy, absorption was studied by FTIR and VCD spectroscopies. It was initially proposed, that surface structure induced by rotationally polarized laser beam will have chiral nature and response. Actual experiments indicate that circularly polarized light induces the formation of many microscopic spirals or more complex structures on the polymer surface. Shape and density of the surface structures were determined by experimental conditions and in all cases the initially nonchiral doped PMMA becomes equivalent to the classical, optically active media. In particular, created structures gave rise to a photoinduced circular dichroism response, with the response being determined by experimental conditions. The resulting chiral structures show long-time stability and offer interesting possibility to manipulate the light polarization.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials