In this presentation, I report on the self-organized photonic crystals (PCs) of organic and polymer materials for laser applications. Here the self-organized PCs correspond to chiral liquid crystals (CLCs) and colloidal crystals (CCs). First, CLC molecules self-organize the supramolecular helical arrangement by the helical twisting power like as 1-D PC structure. When the fluorescent dye-doped CLC is optically excited with a linearly polarized beam, the laser emission appears at the photonic band gap (PBG) edge(s) of CLC hosts. The optically excited laser emission shows circularly polarized characteristic, even though the excitation beam is linearly polarized. Applying voltages to the optically excited CLC cells enables reversible switching of the laser action as a result of changes in the supramolecular helical structure of CLC host. Moreover, we succeed in the phototunable laser emission by using photoreactive CLCs. Second research topic is establishment of new potential utilities of CC structures of polymer micro-particles. Monodispersed micro-particles have an intrinsic capability to self-assemble the face-centered cubic lattice structures like as 3-D PCs on substrates from the suspension solutions. The highly ordered architectures of colloidal particles are called as the CCs. The laser cavity structure consists of an intermediate light-emitting layer of a fluorescent dye sandwiched between a pair of polymeric CC films. Optical excitation of the device gives rise to the laser oscillation within the photonic band-gap of the CC films. Interestingly, the laser action can be generated by optical excitation even though the CC laser device of all-polymer materials becomes bent shape by mechanical stress.

Date Published: 28 August 2008
PDF: 10 pages
Proc. SPIE 7031, Active Photonic Crystals II, 703103 (28 August 2008); doi: 10.1117/12.796549

Published in SPIE Proceedings Vol. 7031:
Active Photonic Crystals II
Sharon M. Weiss; Ganapathi S. Subramania; Florencio García-Santamaría, Editor(s)