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A fiber-optic strain sensor that can show strain via color change and which can be viewed using human eyes has demand in the civil engineering field for alerting purposes. A previous sensor was fabricated using PMMA (Poly(methyl methacrylate)), which had the exceeding hardness to exhibit satisfactory sensor performance. In this research, an elastomer-based fiber-optic structure was fabricated to enhance the elastic response of such sensors and to enlarge the waveguide cross section. Various organic fluorophores were added to the core and cladding regions of the elastic waveguide to induce energy flow from the core to the cladding when stress is applied to the waveguide. Elastomer pairs suitable for the core and cladding were selected from among several candidate materials having high transparency. A method of dispersing fluorophores to each host elastomer and constructing an excellent core–cladding interface using the selected materials was proposed. To investigate the time-dependent changes in the fluorescence of the doped elastomer waveguide, the absorption and emission spectra were monitored after the host elastomers were cured.
Chie Hirose; Nobuko Fukuda; Takafumi Sassa; Koji Ishibashi; Tsuyoshi Ochiai; Rei Furukawa. Fabrication of a Fluorophore-Doped Cylindrical Waveguide Structure Using Elastomers for Visual Detection of Stress. Fibers 2019, 7, 37 .
AMA StyleChie Hirose, Nobuko Fukuda, Takafumi Sassa, Koji Ishibashi, Tsuyoshi Ochiai, Rei Furukawa. Fabrication of a Fluorophore-Doped Cylindrical Waveguide Structure Using Elastomers for Visual Detection of Stress. Fibers. 2019; 7 (5):37.
Chicago/Turabian StyleChie Hirose; Nobuko Fukuda; Takafumi Sassa; Koji Ishibashi; Tsuyoshi Ochiai; Rei Furukawa. 2019. "Fabrication of a Fluorophore-Doped Cylindrical Waveguide Structure Using Elastomers for Visual Detection of Stress." Fibers 7, no. 5: 37.
In this study, we improved the hydrogen production efficiency by combining a photosystem I/platinum nanoparticle composite with an artificial light harvesting dye, Lumogen Red.
Haruki Nagakawa; Ayano Takeuchi; Yuya Takekuma; Tomoyasu Noji; Keisuke Kawakami; Nobuo Kamiya; Mamoru Nango; Rei Furukawa; Morio Nagata. Efficient hydrogen production using photosystem I enhanced by artificial light harvesting dye. Photochemical & Photobiological Sciences 2019, 18, 309 -313.
AMA StyleHaruki Nagakawa, Ayano Takeuchi, Yuya Takekuma, Tomoyasu Noji, Keisuke Kawakami, Nobuo Kamiya, Mamoru Nango, Rei Furukawa, Morio Nagata. Efficient hydrogen production using photosystem I enhanced by artificial light harvesting dye. Photochemical & Photobiological Sciences. 2019; 18 (2):309-313.
Chicago/Turabian StyleHaruki Nagakawa; Ayano Takeuchi; Yuya Takekuma; Tomoyasu Noji; Keisuke Kawakami; Nobuo Kamiya; Mamoru Nango; Rei Furukawa; Morio Nagata. 2019. "Efficient hydrogen production using photosystem I enhanced by artificial light harvesting dye." Photochemical & Photobiological Sciences 18, no. 2: 309-313.
With the aim of understanding the excitation energy transfer mechanism in natural photosynthetic membranes, light-harvesting (LH)2 and LH1-reaction center, which are pigment-protein complexes separated from Rhodobacter sphaeroides, were aligned on a planar electrode surface in stripe patterns at 5 µm intervals. Observation of the absorption spectrum and fluorescence microphotographs revealed selective immobilization and conservation of the pigments. Photocurrent signals were obtained when the electrode was illuminated at either 880 or 800 nm. The fabricated structure was confirmed to function as a natural photosynthetic membrane with the highest photocurrent signal being obtained when using a co-immobilized substrate under excitation at 800 nm.
Rei Furukawa; Masaharu Kondo; Shunsuke Yajima; Kaori Harada; Kenji V. P. Nagashima; Morio Nagata; Kouji Iida; Takehisa Dewa; Mamoru Nango. Selective immobilization of bacterial light-harvesting proteins and their photoelectric responses. MRS Communications 2018, 8, 1124 -1128.
AMA StyleRei Furukawa, Masaharu Kondo, Shunsuke Yajima, Kaori Harada, Kenji V. P. Nagashima, Morio Nagata, Kouji Iida, Takehisa Dewa, Mamoru Nango. Selective immobilization of bacterial light-harvesting proteins and their photoelectric responses. MRS Communications. 2018; 8 (3):1124-1128.
Chicago/Turabian StyleRei Furukawa; Masaharu Kondo; Shunsuke Yajima; Kaori Harada; Kenji V. P. Nagashima; Morio Nagata; Kouji Iida; Takehisa Dewa; Mamoru Nango. 2018. "Selective immobilization of bacterial light-harvesting proteins and their photoelectric responses." MRS Communications 8, no. 3: 1124-1128.
We evaluate and compare radio-over-fiber transmission performances in terms of fiber misaligned connection and reflection noise in silica multimode fibers and plastic optical fibers (POFs). The results show that POFs have much higher transmission performances.
Yuki Matsumoto; Motoharu Matsuura; Rei Furukawa; Azusa Inoue; Yasuhiro Koike. Intrinsic Robustness of Fiber Misaligned Connections and Reflection Noise in Plastic Optical Fiber Links for Cost-Effective Radio-Over-Fiber Systems. Optical Fiber Communication Conference 2016, 1 .
AMA StyleYuki Matsumoto, Motoharu Matsuura, Rei Furukawa, Azusa Inoue, Yasuhiro Koike. Intrinsic Robustness of Fiber Misaligned Connections and Reflection Noise in Plastic Optical Fiber Links for Cost-Effective Radio-Over-Fiber Systems. Optical Fiber Communication Conference. 2016; ():1.
Chicago/Turabian StyleYuki Matsumoto; Motoharu Matsuura; Rei Furukawa; Azusa Inoue; Yasuhiro Koike. 2016. "Intrinsic Robustness of Fiber Misaligned Connections and Reflection Noise in Plastic Optical Fiber Links for Cost-Effective Radio-Over-Fiber Systems." Optical Fiber Communication Conference , no. : 1.
We experimentally demonstrate that a graded-index plastic optical fiber (GI POF) can significantly reduce reflection noise in a multimode fiber link with a vertical-cavity surface-emitting laser (VCSEL). By directly observing beams backreflected to the VCSEL, we show that the noise reduction effect is closely related to random mode coupling because of light scattering by microscopic heterogeneities in the GI POF core material. This suggests that intrinsic mode coupling can lower the self-coupling efficiency of the light backreflected to the VCSEL cavity through beam quality degradation. Using GI POFs, low-cost radio-over-fiber systems for indoor networks can be realized without optical isolators or fiber end-face polishing.
Azusa Inoue; Rei Furukawa; Motoharu Matsuura; Yasuhiro Koike. Reflection noise reduction effect of graded-index plastic optical fiber in multimode fiber link. Optics Letters 2014, 39, 3662 -3665.
AMA StyleAzusa Inoue, Rei Furukawa, Motoharu Matsuura, Yasuhiro Koike. Reflection noise reduction effect of graded-index plastic optical fiber in multimode fiber link. Optics Letters. 2014; 39 (12):3662-3665.
Chicago/Turabian StyleAzusa Inoue; Rei Furukawa; Motoharu Matsuura; Yasuhiro Koike. 2014. "Reflection noise reduction effect of graded-index plastic optical fiber in multimode fiber link." Optics Letters 39, no. 12: 3662-3665.
We have evaluated and compared modal noise induced in a graded-index silica multimode fiber (GI-MMF) link and a graded-index plastic optical fiber (GI-POF) link with the misaligned fiber connections. In radio over fiber (RoF) systems using these optical fibers, modal noise appears as unwanted amplitude modulation in the received signal, and results in degradation of the RoF transmission performance. In this work, we have evaluated the modal noise induced in GI-MMFs and GI-POFs with its same core diameter of 50 μm. Our results show that GI-POFs have an inherently higher tolerance to misaligned connection and less modal noise than GI-MMFs in terms of both the error-vector magnitude and the speckle pattern of the transmitted signals.
Motoharu Matsuura; Rei Furukawa; Yuki Matsumoto; Azusa Inoue; Yasuhiro Koike. Evaluation of modal noise in graded-index silica and plastic optical fiber links for radio over multimode fiber systems. Optics Express 2014, 22, 6562 -6568.
AMA StyleMotoharu Matsuura, Rei Furukawa, Yuki Matsumoto, Azusa Inoue, Yasuhiro Koike. Evaluation of modal noise in graded-index silica and plastic optical fiber links for radio over multimode fiber systems. Optics Express. 2014; 22 (6):6562-6568.
Chicago/Turabian StyleMotoharu Matsuura; Rei Furukawa; Yuki Matsumoto; Azusa Inoue; Yasuhiro Koike. 2014. "Evaluation of modal noise in graded-index silica and plastic optical fiber links for radio over multimode fiber systems." Optics Express 22, no. 6: 6562-6568.
Poly-(methyl methacrylate-co-benzyl methacrylate) polarization-maintaining optical fibers are known for their high response to normal stress. In this report, responses to higher stress levels up to 0.45 MPa were investigated. The stress amplitude and direction in the fiber cross section were calculated and analyzed with a coincident mode-field obtained from the near-field pattern. The stress amplitude varies significantly in the horizontal direction and is considered to create multiple phases, explaining the measurement results. To investigate possible permanent deformation, the core yield point profile was analyzed. Although it largely exceeds the average applied stress, the calculated stress distribution indicates that the core could partially experience stress that exceeds the yield point.
Rei Furukawa; Morio Nagata; Kenji Mishima; Motoharu Matsuura; Azusa Inoue; Akihiro Tagaya; Yasuhiro Koike. Core stress distribution of phase shifting multimode polymer optical fiber. Applied Physics Letters 2013, 103, 213301 .
AMA StyleRei Furukawa, Morio Nagata, Kenji Mishima, Motoharu Matsuura, Azusa Inoue, Akihiro Tagaya, Yasuhiro Koike. Core stress distribution of phase shifting multimode polymer optical fiber. Applied Physics Letters. 2013; 103 (21):213301.
Chicago/Turabian StyleRei Furukawa; Morio Nagata; Kenji Mishima; Motoharu Matsuura; Azusa Inoue; Akihiro Tagaya; Yasuhiro Koike. 2013. "Core stress distribution of phase shifting multimode polymer optical fiber." Applied Physics Letters 103, no. 21: 213301.
Intrinsic mode coupling in a graded-index plastic optical fiber (GI POF) is investigated using the developed coupled power theory for a GI POF with a microscopic heterogeneous core. The results showed that the intrinsic material properties can induce random power transitions between all the guided modes, whereas the structural deformation of microbending results in nearest-neighbor coupling. It was numerically demonstrated that efficient group-delay averaging due to intrinsic mode coupling brings the pronounced bandwidth enhancement in fibers with much shorter length than the case of glass multimode fibers.
Azusa Inoue; Takafumi Sassa; Rei Furukawa; Kenji Makino; Atsushi Kondo; Yasuhiro Koike. Efficient group delay averaging in graded-index plastic optical fiber with microscopic heterogeneous core. Optics Express 2013, 21, 17379 -17385.
AMA StyleAzusa Inoue, Takafumi Sassa, Rei Furukawa, Kenji Makino, Atsushi Kondo, Yasuhiro Koike. Efficient group delay averaging in graded-index plastic optical fiber with microscopic heterogeneous core. Optics Express. 2013; 21 (14):17379-17385.
Chicago/Turabian StyleAzusa Inoue; Takafumi Sassa; Rei Furukawa; Kenji Makino; Atsushi Kondo; Yasuhiro Koike. 2013. "Efficient group delay averaging in graded-index plastic optical fiber with microscopic heterogeneous core." Optics Express 21, no. 14: 17379-17385.
Shunsuke Yajima; Rei A. Furukawa; Morio Nagata; Shunsuke Sakai; Masaharu Kondo; Kouji Iida; Takehisa Dewa; Mamoru Nango. Two-dimensional patterning of bacterial light-harvesting 2 complexes on lipid-modified gold surface. Applied Physics Letters 2012, 100, 233701 .
AMA StyleShunsuke Yajima, Rei A. Furukawa, Morio Nagata, Shunsuke Sakai, Masaharu Kondo, Kouji Iida, Takehisa Dewa, Mamoru Nango. Two-dimensional patterning of bacterial light-harvesting 2 complexes on lipid-modified gold surface. Applied Physics Letters. 2012; 100 (23):233701.
Chicago/Turabian StyleShunsuke Yajima; Rei A. Furukawa; Morio Nagata; Shunsuke Sakai; Masaharu Kondo; Kouji Iida; Takehisa Dewa; Mamoru Nango. 2012. "Two-dimensional patterning of bacterial light-harvesting 2 complexes on lipid-modified gold surface." Applied Physics Letters 100, no. 23: 233701.
Rei A. Furukawa; Akihiro Tagaya; Yasuhiro Koike. Modal analysis of a multimode polarization-maintaining plastic optical fiber fabricated using poly(methyl methacrylate/benzyl methacrylate) copolymer. Applied Physics Letters 2008, 93, 103303 .
AMA StyleRei A. Furukawa, Akihiro Tagaya, Yasuhiro Koike. Modal analysis of a multimode polarization-maintaining plastic optical fiber fabricated using poly(methyl methacrylate/benzyl methacrylate) copolymer. Applied Physics Letters. 2008; 93 (10):103303.
Chicago/Turabian StyleRei A. Furukawa; Akihiro Tagaya; Yasuhiro Koike. 2008. "Modal analysis of a multimode polarization-maintaining plastic optical fiber fabricated using poly(methyl methacrylate/benzyl methacrylate) copolymer." Applied Physics Letters 93, no. 10: 103303.