All-optical and electro-optical control of Light in Soft Matter based Photonic Quasi Crystals

Metamaterials (MTMs) and Photonic Quasi-Crystals (PQCs) have attracted the attention of the scientific community in the last few years due to their capability to control the electromagnetic (EM) field in an unusual way. By exploiting MTMs and PQCs, it is possible to realize man-made structures characterized by a selective EM response, which can be also controlled by combining the distinctive properties of reconfigurable soft-matter. Here, we report on our recent efforts devoted to combine nanostructured Thue Morse PQCs [1] and photo/electro responsive Nematic Liquid Crystals (NLCs) [2]. In details, by means of a surface functionalization strategy, we have in-plane aligned NLCs overlaying a Thue Morse PQCs made on a conductive glass substrate; therefore, white light propagating in the glass substrate is outcoupled from the PQC according to its geometrical parameters. Consequently, the extracted single-mode light source can be both all-optically and electro-optically finely enhanced by controlling the refractive index value of the NLC. In our opinion, these results represent a breakthrough in the realization of innovative MTMS based active photonic devices. [1] M. Rippa, R. Capasso, P. Mormile, S. De Nicola, M. Zanella, L. Manna, G. Nenna and L. Petti, Bragg Extraction of Light in 2D Photonic Thue Morse Quasicrystal patterned in Active CdSe/CdS Nanorods-Polymer Nanocomposites, Nanoscale, 5, 331 (2013). [2] L. De Sio, L. Ricciardi, S. Serak, M. La Deda, N. Tabiryan, C. Umeton "Photo-sensitive liquid crystals for optically controlled diffraction gratings" J. Mater. Chem. 22, 6669 (2012)