Articles by Daichi Okada in JoVE
Fabrication of Polymer Microspheres for Optical Resonator and Laser Applications Yohei Yamamoto1,2,3, Daichi Okada1, Soh Kushida1, Zakarias Seba Ngara1, Osamu Oki1 1Faculty of Pure and Applied Sciences, University of Tsukuba, 2Tsukuba Research Center for Interdisciplinary Materials Science (TIMS), University of Tsukuba, 3Center for Integrated Research in Fundamental Science and Technology (CiRfSE), University of Tsukuba Protocols for the synthesis of microspheres from polymers, the manipulation of microspheres, and micro-photoluminescence measurements are presented.
Other articles by Daichi Okada on PubMed
Chiroptical Switching Caused by Crystalline/liquid Crystalline Phase Transition of a Chiral Bowl-shaped Molecule Chemical Communications (Cambridge, England). Mar, 2016 | Pubmed ID: 26948812 The liquid crystal of a chiral bowl-shaped molecule having a central-phosphorus atom and long alkyl chains was developed. The DSC and XRD analyses suggested the formation of columnar liquid crystals of both the enantiopure and racemic compounds. The condensed phase of the enantiopure compound in a thin film exhibited a significant signal in CD spectra, which was switched by a reversible phase transition between the crystalline and liquid crystalline states.
Color-Tunable Resonant Photoluminescence and Cavity-Mediated Multistep Energy Transfer Cascade ACS Nano. Jul, 2016 | Pubmed ID: 27348045 Color-tunable resonant photoluminescence (PL) was attained from polystyrene microspheres doped with a single polymorphic fluorescent dye, boron-dipyrrin (BODIPY) 1. The color of the resonant PL depends on the assembling morphology of 1 in the microspheres, which can be selectively controlled from green to red by the initial concentration of 1 in the preparation process of the microspheres. Studies on intersphere PL propagation with multicoupled microspheres, prepared by micromanipulation technique, revealed that multistep photon transfer takes place through the microspheres, accompanying energy transfer cascade with stepwise PL color change. The intersphere energy transfer cascade is direction selective, where energy donor-to-acceptor down conversion direction is only allowed. Such cavity-mediated long-distance and multistep energy transfer will be advantageous for polymer photonics device application.