1-3hit |
Yuuki MIYAZAKI Kazuo OKAMOTO Kenji OGINO
The novel ladder-shaped polydiacetylene with a terephthalamide linker in the molecular center, namely poly(TPh-bisDA) was synthesized by photo-polymerization. The characteristics of thin films of polymer were dependent upon a casting solvent, but no significant change of backbone conformation of the PDA was observed. Obtained film is expected to be applied to the semi-conducting materials for organic field effect transistors (OFET).
We have fabricated a polymer solid-state microstructure for optical application by two-photon-induced polymerization technique. The photopolymerization resin contains conventional laser-dye and dendrimer. A dendrimer can encapsulate the laser-dyes, limiting cluster formation and intermolecular energy transfer, and promising a high level of optical gain. The effect can be extended to prepare an optically active microstructure using the two-photon-induced polymerization technique. We fabricated a polymeric microcavity, which consisted of < 400 nm-linewidth strips arranged in layer-by-layer structure. The periodic variation in the refractive index gave rise to Bragg reflection. A laser emission was measured in the microcavity under optical excitation. The spectral linewidth was about 0.1 nm above the lasing threshold. We investigate both the material functions in the molecular scale and controlling the device structure for desired applications such as a polymer distributed feedback structure.
Satoshi KAWATA Satoru SHOJI Hong-Bo SUN
Lasers have been established as a unique nanoprocessing tool due to its intrinsic three-dimensional (3D) fabrication capability and the excellent compatibility to various functional materials. Here we report two methods that have been proved particularly promising for tailoring 3D photonic crystals (PhCs): pinpoint writing via two-photon photopolymerization and multibeam interferential patterning. In the two-photon fabrication, a finely quantified pixel writing scheme and a method of pre-compensation to the shrinkage induced by polymerization enable high-reproducibility and high-fidelity prototyping; well-defined diamond-lattice PhCs prove the arbitrary 3D processing capability of the two-photon technology. In the interference patterning method, we proposed and utilized a two-step exposure approach, which not only increases the number of achievable lattice types, but also expands the freedom in tuning lattice constant.