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In this study, we fabricated a device that can be used for water purification in dark areas by combining a light-leakage type plastic optical fiber with a photocatalyst. The light-leakage type fibe...

Photosynthetic pigment–protein-based biophotovoltaic devices are attracting interest as environmentally friendly energy sources. Photosystem I (PSI), a photosynthetic pigment–protein, is a proven biophotovoltaic material because of its abundance and high charge separation quantum efficiency. However, the photocurrent of these biophotovoltaic devices is not high because of their low spectral response. We have integrated an artificial light-harvesting antenna into a PSI-based biophotovoltaic device to expand the spectral response. To fabricate the device, a perylene di-imide derivative (PTCDI) was introduced onto a TiO2 surface as an artificial antenna. In the photovoltaic cells formed by the PTCDI/PSI-assembled TiO2 electrode, the magnitude of the incident photon-to-current conversion efficiency spectrum was significantly enhanced in the range 450–750 nm, and the photocurrent increased to 0.47 mA/cm2. The result indicates that the photons absorbed by PTCDI transfer to PSI via Forster resonance energy transfer.

In this study, we improved the hydrogen production efficiency by combining photosystem I with an artificial light harvesting dye, Lumogen Red. In the reaction system, Lumogen Red allows light absorption and energy transfer to photosystem I by Forster resonance energy transfer; therefore, the Pt nanoparticles act as active sites for hydrogen generation.

Terpolymer of methyl methacrylate, 2,2,2-trifluoroethyl methacrylate, and benzyl methacrylate, that is known to eliminate intrinsic and photoelastic birefringence simultaneously, was adopted to compose a core of a multimode fiber. Polarization-maintaining property of this terpolymer-based fiber was characterized using mode-dependent extinction-ratio measurement and polarization-dependent near-field pattern. Unlike any conventional fiber-optic strain sensors, this terpolymer-based fiber was demonstrated for its capability in detecting strain vector in a use with a dichroic dye.

Phthalocyanine has attractive features as a dopant for plastic optical fibers. Its planar molecular structure and red absorption band are suitable for the design of fiber-optic strain sensors that use the dynamic orientation of dye induced by the deformation of the host matrix. The guidelines to achieve a phthalocyanine-doped fiber with a ruled dispersing manner were investigated. A synthesized fiber using phthalocyanine decorated with tertiary butyl groups showed mode-dependent absorption, which suggested gradual dye distribution in the core radial direction.

The reduction of multipath errors is a significant challenge in the Global Navigation Satellite System (GNSS), especially when receiving non-line-of-sight (NLOS) signals. However, selecting line-of-sight (LOS) satellites correctly is still a difficult task in dense urban areas, even with the latest GNSS receivers. This study demonstrates a new method of utilization of C/N0 of the GNSS to detect NLOS signals. The elevation-dependent threshold of the C/N0 setting may be effective in mitigating multipath errors. However, the C/N0 fluctuation affected by NLOS signals is quite large. If the C/N0 is over the threshold, the satellite is used for positioning even if it is still affected by the NLOS signal, which causes the positioning error to jump easily. To overcome this issue, we focused on the value of continuous time-series C/N0 for a certain period. If the C/N0 of the satellite was less than the determined threshold, the satellite was not used for positioning for a certain period, even if the C/N0 recovered over the threshold. Three static tests were conducted at challenging locations near high-rise buildings in Tokyo. The results proved that our method could substantially mitigate multipath errors in differential GNSS by appropriately removing the NLOS signals. Therefore, the performance of real-time kinematic GNSS was significantly improved.

To utilize RTK-GNSS in urban areas, it is important to predict areas in which it can be used. The performance of RTKGNSS depends on the geometry and number of visible satellites and signal quality. These parameters can potentially be predicted using simulations that consider the relative geometry between the receiver and surrounding objects. In this study, we first verified whether the GNSS signal quality can be correctly predicted using 3D models of buildings and measurement data. Subsequently, we verified whether the FIX status of RTK can be correctly predicted. The results show that the number of the measured and predicted satellites that have good signal quality was in agreement at least 87.8% of the time. We assessed and categorized the RTK-GNSS fixing status using the number of usable satellites. A comparison of the RTK fixed status estimation, using the actual measurements and those from the simulation, agreed within 83.9% of the total.

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 urn 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.

Noble fiber-optic strain sensor using dye-doped polymer optical fiber (POF) was proposed, and its ability to sense stress (strain) by simple viewing of the large-core cross section was proposed. Conventional well-known fiber-optic strain sensors such as BOTDR or FBG types require spectral analysis to determine the strain value. Our sensor does not require expensive equipments such as spectral analyzer or well-tuned light source that are required in conventional fiber-optic strain sensors. A pair of luminescent organic dyes, Coumarin 540A and Rhodamine 6G, that functions as donor and acceptor of excitation energy were doped in core and cladding of the fiber, respectively. By taking this structure, stress applied to the fiber could be detected as an increase in cladding intensity. This happens because emission of core dye leaks to the cladding due to the deformation, and it excites the cladding dye. Using the fabricated POF, change in near field pattern upon different fiber bending diameter was detected. Lasers with three different wavelengths were used; namely, 406 nm, 532 nm, and 635 nm. 406 nm is the optimum wavelength for exciting the Coumarin 540A of the core efficiently. 532 nm excites Rhodamin 6G well, but does not excite Coumarin 540A well. 635 nm excites neither dyes. Pigtail end was coupled to the test fiber with direct contact to the core center of the test fiber in which no cladding excitation was expected. Fibers were stressed in various magnitudes by bending them in different loop diameters, namely, 1.5 cm, 3 cm, and 6 cm. Single loop was created in the middle point of the whole length. Relaxed condition, which the fiber was naturally straightened with no loop, was also investigated. Output beam from the test fiber was analyzed using Near Field Pattern measuring system (Hamamatsu C9664-01G02). In addition, dye-doped POF with lower numerical aperture had shown enhancement in sensitivity. Therefore, it was suggested that sensitivity of the sensor is controllable by further optimization of the waveguide parameters. Therefore, the proposed results suggests a potential for an enhanced fiber-optic stress detection with simpler and inexpensive accessory components.

In this study, we improved the hydrogen production efficiency by combining photosystem I with an artificial light harvesting dye, Lumogen Red. In the reaction system, Lumogen Red allows light absorption and energy transfer to photosystem I by Förster resonance energy transfer; therefore, the Pt nanoparticles act as active sites for hydrogen generation.

A fiber-optic strain sensor using a fluorophore-doped polymer optical fiber (POF) was fabricated at various waveguiding conditions. The effects attributed to each structural feature of the sensor were characterized by observing the sensor's response. Two fluorophores, Coumarin 540A and Rhodamine 6G, were used to dope the core and the cladding of a poly(methyl methacrylate)-based POF, respectively. Using doped POFs with different numerical apertures (NAs), the changes in the fluorophore peaks upon the application of stress were analyzed by applying macrobending(s) to the fiber. Although the sensor response did not show linearity with respect to the NA, it was found that the shape of the Coumarin 540A-attributed peak was a factor that represented the sensor's sensitivity. As a result, the double-cladding structure demonstrated its effectiveness in improving the stress sensitivity.

A stress sensor based on a dye-doped polymeric optical fiber can detect stress by simple comparison of two luminescence peaks from a pair of organic dyes. How the cladding luminescence was induced was analyzed.

Polarization-maintaining (PM) optical fiber is used in high-speed optical communication and fiberoptic interferometric sensing [1]. Existing PM optical fiber that is known for PANDA fibers intentionally form a large birefringence in the core radially [1]. By taking this structure, the PM function is obtained by suppressing the energy exchange between the orthogonal polarization components of the singlemode optical fiber. However, this principle is not effective in multimode fiber. In the past, it has been reported that a polymer optical fiber (POF) with its core fabricated using copolymer that can reduce intrinsic birefringence, namely, methyl methacrylate (MMA) and benzyl methacrylate (BzMA), exhibit a high extinction ratio compared to the other multimode optical fibers on the premise that no load is applied [2]. Therefore, in this study, POF of ternary core including 2,2,2-trifluoroethyl methacrylate (3FMA) in addition to the earlier material pair was fabricated. P (MMA / 3 FMA / BzMA = 52.0 / 42.0 / 6.0 (w / w / w) is known to be effective in eliminating two types of birefringence, namely, photoelastic birefringence and orientational birefringence [3]. As a result, it was proved that polarization maintaining effect is provided even when load is applied to this multimode fiber.

Support system for safe driving heavily depends on global navigation satellite system. Pseudoranges between satellites and vehicles are measured to compute vehicles’ positions and their relative positions. In urban areas, however, multipath errors (MPEs) in pseudoranges, caused by obstruction and reflection of roadside buildings, greatly degrade the precision of relative positions. On the other hand, simply removing all reflected signals might lead to a shortage of satellites in fixing positions. In our previous work, we suggested solving this dilemma by cooperative relative positioning (CoRelPos) which exploits spatial correlation of MPEs. In this paper, we collected the trace data of pseudoranges by driving cars in urban areas, analyzed the properties of MPEs (specifically, their dependency on signal strength, elevation angles of satellites, and receivers’ speeds), and highlighted their spatial correlation. On this basis, the CoRelPos scheme is refined by considering the dynamics of MPEs. Evaluation results under practical vehicular scenarios confirm that properties of MPEs can be exploited to improve the precision of relative positions.

Global navigation satellite system-based positioning plays an important role in support system for safe driving, where relative positions of vehicles are used to prevent collision accidents from happening. In urban areas, however, multipath errors (MPEs) in pseudo-ranges, caused by obstruction and reflection of roadside buildings, greatly degrade the precision of relative positions. On the other hand, simply removing all reflected signals might lead to a shortage of satellites in fixing positions. This dilemma is solved in this paper by exploiting spatial correlation of MPEs. First, by analysis, ray-tracing simulation and testbed experiments, we show that MPEs in pseudo-ranges are spatially correlated in a small area. Then, we suggest a cooperative relative positioning scheme to exploit correlated signals, including reflected ones, in computing relative positions of nearby vehicles. Efficient transmission of pseudo-ranges is also discussed. The proposed scheme, which can be implemented either in a distributed way or via a cloud of intelligent transportation system, helps to improve the precision of relative positions in urban canyons.

Poly(methyl methacrylate/2,2,2-trifluoroethyl methacrylate /benzyl methacrylate)=52/42/6 (w/w/w)) was used for core of a polymer optical fiber (POF) at a purpose to fabricate a birefringence-reduced core (BRC). The fabricated POF had shown almost no phase shift regardless to the stress applied to the fiber. In order to detect stressed direction, dichroic dye was doped in the core of a BRC-POF. A doped BRC-POF fabricated using Magenta dye had shown a variation in output at conditions in which stress vector and incident polarization construct deferent angular relationships. The results are considered to be applicable for detailed monitoring of structures.

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&ndash, 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.

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.

Principle of a novel fiber-optic strain sensor using dye-doped polymer optical fiber (POF) was demonstrated in the earlier ECS meeting[1]. This time, we demonstrate the ability to tune the sensitivity of this sensor by varying the numerical aperture of the fiber. The sensor uses radiative emission-absorption mechanism and it is capable in sensing stress (strain) by simple viewing of the large-core cross section. Conventional well-known fiber-optic strain sensors such as BOTDR or FBG types require spectral analysis to determine the strain value. Our sensor does not require expensive equipment such as spectral analyzer or well-tuned light source that are required in conventional fiber-optic strain sensors. A pair of luminescent organic dyes, Coumarin 540A and Rhodamine 6G, that functions as donor and acceptor of excitation energy were doped in core and cladding of the fiber, respectively. By taking this structure, stress applied to the fiber could be detected as an increase in cladding intensity. This happens because emission of core dye leaks to the cladding due to the deformation, and it excites the cladding dye[2]. POFs with three different NA were fabricated by varying the amount of high-refractive index dopant in the core[2]. Using the fabricated POF, change in near field pattern and output visible spectrum upon different fiber bending diameter were detected. 406 nm output pigtail laser was used in order to excite the donor dye efficiently. Pigtail end was coupled to the test fiber with direct contact to the core center of the test fiber in which no cladding excitation was expected. Fibers were stressed in various magnitudes by bending them in different loop diameters, namely, 1.5 cm, 3 cm, and 6 cm. Single loop was created in the middle point of the whole length. Relaxed condition, which the fiber was naturally straightened with no loop, was also investigated. Output beam from the test fiber was analyzed using Near Field Pattern measuring system (Hamamatsu C9664-01G02) and spectral analyzing system (JASCO MF-3500). As a result, linear change in sensor sensitivity was observed as the NA increases. Therefore, it was suggested that sensitivity of the sensor is controllable by further optimization of the waveguide parameters. Therefore, the proposed results suggests a potential for an enhanced fiber-optic stress detection with simpler and inexpensive accessory components. [1] Kamimura and Furukawa, 232nd ECS meeting. [2] Kamimura and Furukawa,Appl. Phys. Lett. 111, 063301 (2017)

This paper demonstrates a polarimetric pressure measurement using a multimode phase retarder plastic optical fiber fabricated from a birefringence-controllable copolymer. An optimal composition that gives the most pronounced response to pressure was studied by comparing the extinction ratio of fibers fabricated with different copolymer compositions. A simple sensor design with a single-fiber structure was proposed that has detection capabilities similar to those of the conventional dual-path structure of a Mach-Zehnder interferometer. A linear relationship between the fiber birefringence and the applied pressure was observed in a range from 0 to 0.06 MPa. A polarimetric sensitivity of 1.56 x 10(-5) MPa(-1) was obtained experimentally from the relationship between the birefringence and pressure.

In order to propose a multimode polarization-maintaining fiber in a large core diameter, polarization-maintaining graded-index plastic optical fiber (PMGIPOF) was fabricated using a birefringence-reduced copolymer of poly(methyl methacrylate/benzyl methacrylate). Successful reduction of orientational birefringence in the PMGIPOF was verified using polarized optical microscopy. The extinction ratio measured from the PMGIPOF was significantly higher than the value obtained for the step-index (SI) POF (14.3 and 0.5 dB for 1 m, respectively). Photoelastic birefringence in the PMGIPOF was studied using fiber macrobending. Retardation induced by the macrobending was observed in a manner of high regularity in the PMGIPOF, where as the other types of POFs did not show such regularity. Furthermore, the polarization-maintaining property of the PMGIPOF was effective at maximum 10 m propagation.

A stress sensor based on a dye-doped polymeric optical fiber is able to detect stress by simple comparison of two luminescence peaks from a pair of energy transfer organic dyes. Coumarin 540A (donor) and Rhodamine 6G (acceptor) were doped in the core and cladding of the fiber, respectively. For various laser wavelengths, the change in the near-field pattern and visible emission spectrum upon variation in the fiber bending diameter was evaluated. From a comparison with a low-numerical-aperture fiber, it is shown that the sensitivity of the sensor is controllable by optimization of the waveguide parameters.

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.

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.

We propose a polarization-maintaining waveguide fabricated with a large waveguiding area (core diameter: 750 µm) using polymeric material. We previously developed and demonstrated a zero-birefringence copolymer in a film structure of 40 to 70 µm thickness. This time, we have fabricated a 20-m-long optical fiber using the same copolymer as the core material. The polarization-maintaining performance of the low-birefringence polymer optical fiber was studied by comparison with that for other types of plastic optical fibers. As a result, the low-birefringence polymer optical fiber showed a high extinction ratio for fiber lengths between 0.4 and 20 m.

Position information plays an important role in support system for safe driving, where inter-vehicle distance is used to prevent collision accidents from happening. In urban areas, however, multipath propagation of GPS signals degrades the accuracy of absolute positions and the deduced relative position. On the other hand, simply removing reflected signals might lead to a shortage of satellites in fixing positions. In our previous work, we suggested cooperative relative positioning to improve the accuracy of relative positions of adjacent vehicles so as to prevent collision accidents from happening. In this paper, we focus on intersections, which are risky areas for vehicles where accidents occur with a higher probability than other areas, then investigate whether our scheme can help to improve the accuracy of relative positions at intersections. More specifically, we evaluate multipath errors due to reflection/diffraction and analyze their correlation between receivers around intersections. We find that (i) Our system helps to improve the accuracy of relative positions of vehicles running on the same road, (ii) The spatial correlation of positioning signals decreases as vehicles get nearer to intersections. As a result of the initial step to focus on intersections, only relying on our scheme is insufficient and other measures become necessary as well in order to get accurate relative positions.

We show that the reflection noises in multimode fiber links can be significantly reduced by using graded-index plastic optical fiber with microscopic heterogeneous core. It is suggested that the intrinsic mode coupling due to the microscopic heterogeneities can result in the noise reduction without optical isolator and fiber end-face polishing.

We evaluate and compare the modal noise impacts in silica-based multimode fibers (MMFs) and plastic optical fibers (POFs) with same core diameters of 50-μm. In this experiment, we show that POFs fundamentally have higher tolerance to offset connection and lower modal noise than MMFs in terms of error-vector magnitude and speckle pattern.

In plants, photosynthetic protein, light harvesting complexes (LHC), holds reaction center called photosystem I or II (PSI or PSII). PSI and PSII receive light energy and convert it to electric flow. This reaction is done in high quantum efficiency. This light-harvesting system enables the plants to use the sun-light efficiently. The converted electron is spatially transferred in multiple chemical steps, and this is called Z scheme. The Z scheme is known to be highly efficient which have nearly no loss of electric energy. Dye-sensitized solar cells (DSSCs) have attracted increasing attention because of its multiple advantages such as low-cost, lightweight, and flexibility. In DSSCs, photogenerated charge carriers in dye are separated and the electrons are injected to conduction band of semiconductor. The charge separating process of DSSCs is similar to that of photosynthesis. Here, we report DSSCs further imitated photosynthesis. The DSSCs we reported have applied the light-harvesting system in photosynthesis. Perylene-based fluorophore was dispersed in electrolyte in order to imitate the roll of chlorophyll, the light harvesting dyes, in nature. This material was chosen due to the high stability against photo-oxidation. Phthalocyanine, the sensitizing dye, was adsorbed on the surface of photoanode to convert photoenergy into an electric flow. The two synthetic dyes are selected to imitate the light-harvesting complex and reaction center, respectively. The energy absorbed at the fluorophore undergoes Förster resonant energy transfer (FRET) to the sensitizing dye. This allows broader spectral absorption, which is beneficial as a characteristic of a solar cell. We have fabricated the above-mentioned imitated system using synthetic dyes, and evaluated its performances on FRET and following electron transfer. Experiments were done as follows. Perylene-based fluorophore was dispersed in iodine/triiodide electrolytes. Three types of fluorophores with different emission wavelengths were used, and electrolytes with different fluorophore concentrations were prepared at the purpose of comparison. Two phthalocyanine-based sensitizing dyes, PcS2 and PcS20 (structures shown in Figure1 a and b), were chosen to investigate the impact of modifications around the main structure. Absorption characteristics of the two materials are nearly the same [1]. The TiO2electrode consisted of a 10 µm nanoporous layer with 3 µm scattering layer was prepared by screen printing. Solar cells were assembled using Surlyn film with platinized counter electrode. The electrolyte solution was introduced through two holes predrilled in the counter electrode. Evaluation of the samples was done using incident-photon-to-current conversion efficiency (IPCE). Figure 2 shows IPCE result of the solar cell using one of the three fluorophore and PcS2. As a result, the DSSCs fabricated using fluorophore with emission well matching the absorption of the sensitizing dye had shown a notable photo-electric conversion around 400-600 nm. The overall photovoltaic performance was greater than the case of no use of fluorophore at all. The solar cells with other two types of fluorophores had not shown this characteristic. Since the emission band of these two fluorophores does not match the adsorption band of the sensitizing dye, it is suggested that FRET reaction is involved in the trend seen in Fig. 2. In conclusions, DSSCs with plant-inspired structure was fabricated and their photovoltaic performance was investigated. Occurrence of FRET among the fluorophore introduced in the electrolyte and the sensitizing dye was suggested from the comparison between the evaluation using fluorophores with different emission band. Synthetizing dyes with different modification had shown the difference, in which suggests that the bulkiness of the dye affects the reaction in the photoanode surface. The overall photovoltaic performance was shown to improve by creating a structure that induces FRET reaction. Ref.1 S. Mori, M. Nagata, Y. Nakahata, K. Yasuta, R. Goto, M. Kimura, and M. Taya J. Am. Chem. Soc. 2010, 132, 4054-4055 Figure 1

Based on the distributed structure of the dye-protein complexes in a photosynthetic membrane, tandem structure with two dye-doped polymer layers was fabricated using the nanoimprint lithography. The energy transfer behavior of different tandem patterns were studied using fluorescence microscope. As a result, duty ration of 1:1 has shown the even fluorescence patterns from the acceptor region, whereas the patterns with higher duty ratios had shown only partial fluorescence from the donor-acceptor interface.

Photosynthetic membrane proteins convert solar light into chemical energy in a significantly high efficiency. Up-to-date reports of the photosynthetic bacterium suggest that such effective light conversion is due to the energy transfer between two light-harvesting (LH) protein complexes that are patterned in two dimensions. In this report, LH complex isolated from Rb. sphaeroides was immobilized onto a patterned gold surface with self-assembled monolayers (SAMs) and lipid bilayers at two main objectives: (1) micron-scale patterning of LH complex, and (2) prevention of quenching for pattern observation.

Optimum combination of light source and medium (optical fiber) for radio-over-fiber application in home optical network was investigated. Japan National Television System Committee (NTSC-J) signal was employed to study the spectrum and the movie quality in different multi-mode fiber link. Noise in glass-based multi-fiber link was lowered by switching the light source from a Fabry-Perot (FP) to a vertical cavity surface-emitting laser (VCSEL). A graded-index plastic optical fiber (GIPOF) link performed a low-noise transmission using FP laser diode. The results supported the GIPOF link to be a good low-cost analog optical link solution using FP laser diode and no lens.

We demonstrate fiber optic analog transmission using NTSC-J signal. Multimode fibers with different core diameter ranging from 9 to 500 μm were tested in terms of transmission capability under different degree of misalignments between fibers. Graded index plastic optical fiber made of 500 μm core have shown high potential in stable analog transmission based on effective light coupling and low modal noise impairment.

Preliminary development towards passive matrix Electrochromic (EC) device in conjugated EC polymer system is discussed. High contrast ratio of dark and bleached pixels is obtained by modification of counter and working electrode capacitance ratio and spacer geometry. Mask patterning and laminar electropolymerization for multicolor EC system application is discussed.

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.