Mitsunori Saito

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We fabricated a terahertz wire-grid polarizer consisting of a micrometer-pitch Al grating on a Si substrate by photolithography and wet etching. The ratio of TM and TE transmittances (extinction ratio) was over 35 dB at 0.5 THz. At the Brewster angle of the Si substrate, the polarization transmittance of a TM wave through the fabricated polarizer exceeded(More)
A fluorescent microdroplet was formed in elastomer to facilitate handling and wavelength tuning. A methanol solution of rhodamine 6G was put into a solidifying polysiloxane resin with a needle. Addition of surfactant was effective to stabilize the droplet. Being excited by a laser pulse (532 nm, > 50 microJ/mm(2), 5 ns), the droplet exhibited a whispering(More)
A mid-IR wire-grid polarizer with a 500 nm pitch was fabricated on a low toxic chalcogenide glass (Sb-Ge-Sn-S system) by the thermal imprinting of periodic grating followed by the thermal evaporation of Al metal. After imprinting, deposition of Al on the grating at an oblique angle produced a wire-grid polarizer. The fabricated polarizer showed polarization(More)
Red, green, and blue phosphorescent resins were developed to realize full-color illuminators that shine without the need for electric power. Red phosphorescence, which used to be weak with conventional red phosphors, was enhanced notably with dye-doped resins in which green or blue phosphors were dispersed uniformly; i.e., brightness increased by seven(More)
Phosphorescent oxides and fluorescent dyes were used together to create a fiber-type illuminator that glows in the dark without the need for electric power. Dye-doped polymer fibers, which were bundled at one end, were linearly arrayed in a polysiloxane resin that contained phosphorescent oxide particles. The phosphorescent resin continued to glow for a(More)
We fabricated an emergency illumination panel by stacking two translucent pictures, one of which was painted with ink and the other with phosphors. When the panel was illuminated by backlight or room light, only the ink-printed picture was visible to the human eye and only the phosphorescent picture was visible in darkness. A two-way mirror was inserted(More)
We examined the effect of an antireflection (AR) coating to enhance the TM transmittance of the wire-grid polarizer. The polarization transmission spectra were calculated using the rigorous coupled-wave analysis. As a result, we verified that an AR film should be inserted between a wire-grid and a Si substrate as regards the TM transmittance and the(More)
Self-controlled photonic switching was achieved by combining the photoconductivity of a semiconductor and the electrical tunability of a liquid crystal (LC). Pulse packets of 1.06 μm wavelength created free carriers in a silicon electrode of an LC cell, which triggered voltage application for LC reorientation. Consequently, polarization direction of the(More)
We designed and fabricated an achromatic infrared wave plate. To examine its phase retardation characteristics, the birefringence was calculated using the effective medium theory. A wave plate with a subwavelength grating was fabricated by direct imprint lithography on a low toxic chalcogenide glass (Sb-Ge-Sn-S system) based on calculated results. As a(More)
A smart polymer was fabricated to construct a photonic interconnection that transmitted frequent signals and blocked occasional signals. A photochromic dye in the polymer was colored by violet light and bleached by green light. Green signal pulses self-formed their optical path by bleaching dye molecules as they propagated in the opaque (colored) polymer.(More)