Ryotaro Konoike

On-demand transfer of trapped photons on a chip.

Researchers experimentally demonstrate on-demand transfer of trapped photons on a photonic crystal chip for the first time. Photonic crystal nanocavities, which have modal volumes of the order of a cubic wavelength in the material, are of great interest as flexible platforms for manipulating photons. Recent developments in ultra-high quality factor nanocavities with long photon lifetimes have encouraged us to develop an ultra-compact and flexible photon manipulation technology where photons are trapped in networks of such nanocavities. The most fundamental requirement is the on-demand transfer of photons to and from the trapped states of arbitrary nanocavities. We experimentally demonstrate photon transfer between two nearly resonant nanocavities at arbitrary positions on a chip, triggered by the irradiation of a third nonresonant nanocavity using an optical control pulse. We obtain a high transfer efficiency of ~90% with a photon lifetime of ~200 ps.

Design of slotted high quality factor photonic-crystal nanocavities embedded in electro-optic polymers

We improve design quality factors of slotted photonic crystal nanocavities embedded in electro-optic polymers (EOPs), which enables control of resonant wavelengths without the use of light-absorbing free carriers. We form nanocavities by modifying single- and double-slotted line-defect waveguides with lattice-constant modulations analytically determined based on dispersions of the waveguides. A double-slotted nanocavity achieves a fourfold increase in Q factor (36 million) compared to a single-slotted nanocavity with similar modulation of lattice constants. Both structures can realize large concentration of light in the EOP region (50%), and resonant wavelength modulations of ~0.01% are expected with applied voltage of 2 V.

KABUKI-MONO: The Art of Kumadori Facial Expression for Manga and Cosplay

Recently, many local cultures are growing their popularities in the global society by creating various new pop cultures. For example, Japanese Manga (comic) and Anime (animation) are now fascinating young people all around the world. The characters in Manga are being their heroes or heroines. Readers of Manga created a bland new culture called Cosplay (costume play) that means they dress up as same as the characters in their favorable Manga. Cos-play has its origin in Japanese traditional play called Kabuki. In Kabuki there is special face make-up method called Kumadori. Kuwadori is a special way of expressing a persons emotion and also appealing himself to other people. In this paper we propose a system that can change human faces into faces with Kumadori make-ups. Thus people would feel that they are actual Kabuki actors. This system could become a new type of entertainment. Also this would help people understand traditional Japanese culture.

Efficient scheme for on-demand light transfer between distant nanocavities

We propose a robust and efficient scheme for on-demand light transfer between distant nanocavities. We obtained high efficiency of ~90% by numerical simulation. Our proposed scheme provides fundamentals for future optical or quantum information processing.