The Experts below are selected from a list of 249 Experts worldwide ranked by ideXlab platform
Masanori Koshiba - One of the best experts on this subject based on the ideXlab platform.
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magneto photonic crystal slab waveguides with Lower Refractive Index silica claddings
IEEE Photonics Technology Letters, 2007Co-Authors: Naoya Kono, Masanori KoshibaAbstract:This letter proposes a new form of magneto-photonic crystal slab waveguides including nanoporous SiO2, with an extremely low Refractive Index, as the cladding material. These structures allow us to achieve physical strength and to render unnecessary holes extending to cladding layers. Our letter investigates the significance of the waveguide geometry for nonreciprocal phase shifts and losses, using a three-dimensional finite-element method with periodic boundary conditions. The guided modes exhibit small losses well below the light line and high nonreciprocal phase shifts with appropriate parameters, according to the calculations in this letter
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magneto photonic crystal slab waveguides with Lower Refractive Index claddings
Optical Fiber Communication Conference, 2006Co-Authors: Naoya Kono, Masanori KoshibaAbstract:Magneto-photonic crystal slab waveguides which include nanoporous SiO/sub 2/ with a very low Refractive Index as the cladding material, exhibit low losses and high nonreciprocal phase shifts without the need for holes extended to the claddings.
Chii J Chan - One of the best experts on this subject based on the ideXlab platform.
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cell nuclei have Lower Refractive Index and mass density than cytoplasm
Journal of Biophotonics, 2016Co-Authors: Mirjam Schurmann, Paul Muller, Jochen Guck, Jana Scholze, Chii J ChanAbstract:Common perception regards the nucleus as a densely packed object with higher Refractive Index (RI) and mass density than the surrounding cytoplasm. Here, the volume of isolated nuclei is systematically varied by electrostatic and osmotic conditions as well as drug treatments that modify chromatin conformation. The Refractive Index and dry mass of isolated nuclei is derived from quantitative phase measurements using digital holographic microscopy (DHM). Surprisingly, the cell nucleus is found to have a Lower RI and mass density than the cytoplasm in four different cell lines and throughout the cell cycle. This result has important implications for conceptualizing light tissue interactions as well as biological processes in cells.
Jochen Guck - One of the best experts on this subject based on the ideXlab platform.
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response to comment on cell nuclei have Lower Refractive Index and mass density than cytoplasm
Journal of Biophotonics, 2018Co-Authors: Paul Muller, Jochen GuckAbstract:In a recent study entitled "Cell nuclei have Lower Refractive Index and mass density than cytoplasm," we provided strong evidence indicating that the nuclear Refractive Index (RI) is Lower than the RI of the cytoplasm for several cell lines. In a complementary study in 2017, entitled "Is the nuclear Refractive Index Lower than cytoplasm? Validation of phase measurements and implications for light scattering technologies," Steelman et al. observed a Lower nuclear RI also for other cell lines and ruled out methodological error sources such as phase wrapping and scattering effects. Recently, Yurkin composed a comment on these 2 publications, entitled "How a phase image of a cell with nucleus Refractive Index smaller than that of the cytoplasm should look like?," putting into question the methods used for measuring the cellular and nuclear RI in the aforementioned publications by suggesting that a Lower nuclear RI would produce a characteristic dip in the measured phase profile in situ. We point out the difficulty of identifying this dip in the presence of other cell organelles, noise, or blurring due to the imaging point spread function. Furthermore, we mitigate Yurkin's concerns regarding the ability of the simple-transmission approximation to compare cellular and nuclear RI by analyzing a set of phase images with a novel, scattering-based approach. We conclude that the absence of a characteristic dip in the measured phase profiles does not contradict the usage of the simple-transmission approximation for the determination of the average cellular or nuclear RI. Our response can be regarded as an addition to the response by Steelman, Eldridge and Wax. We kindly ask the reader to attend to their thorough ascertainment prior to reading our response.
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cell nuclei have Lower Refractive Index and mass density than cytoplasm
Journal of Biophotonics, 2016Co-Authors: Mirjam Schurmann, Paul Muller, Jochen Guck, Jana Scholze, Chii J ChanAbstract:Common perception regards the nucleus as a densely packed object with higher Refractive Index (RI) and mass density than the surrounding cytoplasm. Here, the volume of isolated nuclei is systematically varied by electrostatic and osmotic conditions as well as drug treatments that modify chromatin conformation. The Refractive Index and dry mass of isolated nuclei is derived from quantitative phase measurements using digital holographic microscopy (DHM). Surprisingly, the cell nucleus is found to have a Lower RI and mass density than the cytoplasm in four different cell lines and throughout the cell cycle. This result has important implications for conceptualizing light tissue interactions as well as biological processes in cells.
Naoya Kono - One of the best experts on this subject based on the ideXlab platform.
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magneto photonic crystal slab waveguides with Lower Refractive Index silica claddings
IEEE Photonics Technology Letters, 2007Co-Authors: Naoya Kono, Masanori KoshibaAbstract:This letter proposes a new form of magneto-photonic crystal slab waveguides including nanoporous SiO2, with an extremely low Refractive Index, as the cladding material. These structures allow us to achieve physical strength and to render unnecessary holes extending to cladding layers. Our letter investigates the significance of the waveguide geometry for nonreciprocal phase shifts and losses, using a three-dimensional finite-element method with periodic boundary conditions. The guided modes exhibit small losses well below the light line and high nonreciprocal phase shifts with appropriate parameters, according to the calculations in this letter
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magneto photonic crystal slab waveguides with Lower Refractive Index claddings
Optical Fiber Communication Conference, 2006Co-Authors: Naoya Kono, Masanori KoshibaAbstract:Magneto-photonic crystal slab waveguides which include nanoporous SiO/sub 2/ with a very low Refractive Index as the cladding material, exhibit low losses and high nonreciprocal phase shifts without the need for holes extended to the claddings.
Francisco J Arregui - One of the best experts on this subject based on the ideXlab platform.
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two layer nanocoatings in long period fiber gratings for improved sensitivity of humidity sensors
IEEE Transactions on Nanotechnology, 2008Co-Authors: Jesus M Corres, Ignacio R Matias, I Del Villar, Francisco J ArreguiAbstract:A relative humidity sensor based on the deposition of electrostatic self-assembled alumina ( Al2O3) and poly(sodium 4-styrenesulfonate) on the cladding of a long-period fiber grating (LPFG) has been designed. The sensitive material has a Lower Refractive Index than that of the fiber cladding, which limits the sensitivity of the LPFG response. In order to enhance its sensitivity, a previous high Refractive Index coating has been deposited. The overlay thickness is of the order of magnitude of the light wavelength used to interrogate the sensor. A theoretical model of multilayer cylindrical waveguides based on coupled-mode theory has been used to predict the phenomenon. Experimentally, an increased wavelength shift of the attenuation bands (75%) was obtained during the fabrication of the sensor, and, what is more important, the sensitivity was improved by a ratio of almost four. The proposed method improves the performance of LPFG-based sensors characterized by overlays of low Refractive Index.
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enhancement of sensitivity in long period fiber gratings with deposition of low Refractive Index materials
Optics Letters, 2005Co-Authors: Ignacio Del Villar, Ignacio R Matias, Francisco J ArreguiAbstract:It was proved [Opt. Lett.30, 720 (2005) ] that the deposition of an overlay of higher Refractive Index than that of the cladding on a long-period fiber grating (LPFG) causes large shifts in the attenuation bands induced by the grating. The result is an enhancement of the sensitivity of the LPFG to variations in the ambient and overlay Refractive indices or the overlay thickness. The limitation of the previous design to materials with higher Refractive indices than that of the cladding of the LPFG is overcome with a five-layer model. To this purpose, a first overlay of higher Refractive Index than that of the cladding of the LPFG will enhance the sensitivity of the device to variations in the Refractive Index of a second overlay of Lower Refractive Index than that of the cladding of the LPFG. Moreover, it is proved that, if the second overlay is thick enough, its behavior resembles that of an infinite layer.
