A5079144077- Photonic and Optical Devices
- Liquid Crystal Research Advancements
- Advanced Fiber Optic Sensors
- Advanced Fiber Laser Technologies
- Optical Polarization and Ellipsometry
- Semiconductor Lasers and Optical Devices
- Orbital Angular Momentum in Optics
- Optical Coatings and Gratings
- Advanced Optical Imaging Technologies
- Photonic Crystals and Applications
- Optical Coherence Tomography Applications
- Advanced optical system design
- Photorefractive and Nonlinear Optics
- Analytical Chemistry and Sensors
- Terahertz technology and applications
- Plant Reproductive Biology
- Advanced Optical Sensing Technologies
- Advanced Photonic Communication Systems
- Metamaterials and Metasurfaces Applications
- Coronary Interventions and Diagnostics
- Optical Network Technologies
- Molecular spectroscopy and chirality
- Acoustic Wave Resonator Technologies
- Optical measurement and interference techniques
- Cardiac Imaging and Diagnostics
Nagaoka University of Technology
2015-2024
Nagaoka University
2013-2024
Japan Science and Technology Agency
2022-2024
The University of Tokyo
2023-2024
Tokyo Institute of Technology
1997-2023
Yokohama National University
2020-2023
Centre for Research in Engineering Surface Technology
2022
Center for Responsible Travel
2022
Centre de Recherche en Économie et Statistique
2022
Kumamoto University
2021
Abstract During the current coronavirus disease 2019 (COVID-19) pandemic, a variety of mutations have accumulated in viral genome severe acute respiratory syndrome 2 (SARS-CoV-2) and, at time writing, four variants concern are considered to be potentially hazardous human society 1 . The recently emerged B.1.617.2/Delta variant is closely associated with COVID-19 surge that occurred India spring 2021 (ref. ). However, virological properties remain unclear. Here we show highly fusogenic and...
Objective: The aim was to investigate the role of local formation angiotensin II and bradykinin in reduction myocardial infarct size. Methods: Bilaterally nephrectomised male mongrel dogs were used. Effects compared pretreatment with three inhibitors forming enzyme – captopril (an converting inhibitor), nafamostat (a serine protease chymostatin cysteine inhibitor) - on left anterior descending coronary artery occlusion. Haemodynamic variables monitored blood collected from interventricular...
A disulfide bond between two extracellular cysteines, conserved in all G-protein-coupled receptors, is believed to be critical for stabilization of the ligand-binding pocket.The &-adrenergic receptor (&-AR) contains cysteines (CYS'~' and Cys") as well other ( C ~S ' ~ Cys'").The specificity interactions these four has not yet been clearly established.Mutants encoding alanines specific &-AR gene were constructed expressed COS-1 Chinese hamster ovary cells.Ala106, Ala1s4*1w)Je1,...
A polarization-probe polarization-imaging (PPPI) system was developed for the near-infrared (NIR) regime. This comprises two components operating as a polarization generator and analyzer to enable image capture under polarized light illumination. The captured images contain considerable object information because illuminating beams are affected by many of Mueller matrix elements. By assembling camera using liquid crystal retarders grating, PPPI offers potential measure Stokes parameters...
We constructed a hyperspectral circular polarization (S
Brillouin optical correlation-domain reflectometry (BOCDR) is a technique for measuring the distribution of strain and temperature along an fiber, offering advantages such as operation with light injection from one end sensing relatively high spatial resolution, random-access capability to points. However, it faces trade-off between resolution measurement range. In response, low-coherence BOCDR using randomly modulated source has been proposed, but this method requires variable delay line...
We recorded anisotropic gratings by polarization holographic recording in azobenzene-containing polymeric films doped with a 9-ethylcarbazole (ECZ) plasticizer. Using polarimeter, we measured real time the Stokes parameters of beams diffracted from gratings. analyzed these data on basis theoretical model that accounted for distribution birefringence caused molecular reorientation as well surface relief deformation mass transportation. Our results indicated increasing ECZ doping level...
We present a universal polarization terahertz (THz) phase controller using randomly aligned liquid crystal (LC) cell with graphene electrodes. The LC was fabricated nematic and two quartz substrates that were coated monolayer of as the transparent electrode. in prepared without any alignment treatments aligned. size random domains width disclination lines layer several tens microns. These textures disappeared when an alternating voltage applied to through layers. Using THz time domain...
Brillouin optical correlation-domain reflectometry (BOCDR) is known as one of the distributed fiber-optic strain/temperature sensing techniques. Recently, a high-speed BOCDR configuration with no measurable strain limit has been developed, but only sampling rate 50 Hz experimentally demonstrated, limited by use commercial microwave frequency sweeper (MFS). In this work, replacing MFS an independent voltage-controlled oscillator driven function generator, we show via vibration detection that...
We fabricated a terahertz (THz) polarization converter using twisted nematic (TN) liquid crystal (LC) cell. Poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT/PSS) films coated on quartz glass substrates were used as electrode layers in the TN LC The PEDOT/PSS rubbed unidirectionally rayon cloth to align LC, thereby also serving an alignment layer. azimuthal surface anchoring strength of was measured be 5 × 10−4 J/m2 Néel wall method, which is similar that typical polymeric...
All the previous configurations of optical correlation-domain reflectometry (OCDR) have been based on direct modulation laser driving current. However, some lasers are not designed for high-speed large-amplitude modulation, and amplitude frequency mutually dependent. In this work, to mitigate these drawbacks, we propose an external scheme OCDR. After confirming its basic operation, show that a non-specially can be employed. We also clarify interdependence is negligibly small in scheme, which...
A lot of research on liquid crystal polarization gratings (LCPGs) that can separate circularly polarized light with 100% diffraction efficiency has been conducted in the visible and near-infrared wavelength regions. In this paper, we tried to design fabricate LCPGs are available for use mid- far-infrared (MIR FIR) The materials making were selected view low absorption characteristics measured by a Fourier-transform infrared (FT-IR) spectrometer. designed 3.88 µm 9.5-10.6 fabricated,...
Abstract Light detection and ranging (LiDAR) measures distance by emitting light onto targets analyzing reflections. In addition to conventional LiDAR systems based on time-of-flight frequency-modulated continuous-wave methods, correlation-domain has been developed but with some challenges in miniaturization due the use of a long delay fiber. This study addresses this issue specifying modulation conditions removing We then demonstrate measurement simplified LiDAR. result enhances potential...
We designed and fabricated a liquid crystal (LC) retarder that operates within mid-infrared (MIR) far-infrared (FIR) wavelength regions. Fluorine-based mixed LCs BaF 2 substrates were employed to assemble the LC on basis of their absorption spectra. A thin NiCr film, which served as semitransparent electrode in infrared region, was also formed substrate. The showed transmittances 40% 42% at wavelengths 3.88µm 9.5µm, respectively. Here, we demonstrated phase shift can be electrically...
This paper presents a high-speed Raman temperature sensor that is highly compatible with current strain sensors. Challenging conventional assumptions, we found at communication wavelength of 193 THz, the optimal frequency for measuring scattering power not typically dominant 206 linked to stimulated scattering, but rather around 195 in proximity Rayleigh peak. Our study demonstrates effectiveness real-time sensing through monitoring fluctuations this particular frequency. © 2024 Elsevier...
Since liquid crystal molecules exhibit anisotropic absorption in the infrared region, there is concern about changes diffraction properties of polarization gratings (PGs) made crystals. In this study, we investigated theory efficiency circular PGs with circularly polarized characteristics when they have absorption. We found that separation function light was maintained even presence The usefulness discussed experimental results temperature dependence a PG at 10.2 μ m.
Optical correlation-domain reflectometry (OCDR) is an interference-based method for measuring the reflectivity distribution of optical fibers using periodic frequency-modulated light. OCDR yields experimental results that cannot be explained solely by existing theories, such as appearance ghost peaks at positions where reflection points are not anticipated, thus indicating insufficient theoretical foundation. To elucidate this behavior, "beat-spectrum theory" has been proposed. Although...
A tunable dichroic polarization beam splitter (tunable DPBS) simultaneously performs the follow functions: 1. Separation of a polarized incident into multiple pairs orthogonally beams; 2. propagation direction two wavelength beams after passing through DPBS; and 3. Control both advanced separation capabilities by varying temperature DPBS. This novel complex optical property is realized diffraction phenomena using designed three-dimensional periodic structure aligned liquid crystals in DPBS,...
We demonstrate basic operation of Brillouin optical correlation-domain reflectometry (BOCDR) based on an external modulation scheme, which can mitigate three demerits a conventional direct scheme. A 0.8 m long strain in 2.8 silica fiber is successfully detected distributed manner. This scheme be employed not only BOCDR but also analysis.
We report a terahertz (THz) metamaterial consisting of metal mesh layer with nematic liquid crystals (LCs). The has subwavelength apertures that function as bandpass filter in the THz spectral range. LCs are embedded and aligned homogeneously apertures. electromagnetic characteristics were calculated finite-difference time-domain method. converts polarization wave during transmission thickness LC can be reduced by two orders magnitude relative to without meta-structures. This increases...
We present a simple yet versatile and practical polarization camera for imaging full Stokes parameters. The developed system consists of one anisotropic diffraction grating plate two electro-switchable retarders obtains in nearly real-time images the light scattered from objects. monochromatic S3 image is obtained by physically separating right left circularly polarized components with aid grating, S1 S2 are fast electro-switching retardation each retarder. has possible applications various...
We have succeeded in forming a polarization grating whose diffraction properties are extremely independent of the incident angle by using polymer liquid crystal exhibiting biaxial optical anisotropy. It is considered that extension path length and decrease effective amplitude anisotropy due to oblique incidences offset and, as result, retardation compensated. The this developed device been experimentally demonstrated theoretically explained.
Holographic binary grating liquid crystal (LC) cells, in which the optical anisotropy was rectangularly modulated even as fabricated using holographic exposure, were by one-step polarization exposure of an empty glass cell, interior coated with a photocrosslinkable polymer LC (PCLC). The present study is great significance that three types cells containing twisted alignments can be simultaneous two PCLC substrates to UV interference beams, are sinusoidally modulated. conversion properties...
A diffractive optical element with a three-dimensional liquid crystal (LC) alignment structure for advanced control of polarized beams was fabricated by highly efficient one-step photoalignment method. This study is great significance because different two-dimensional continuous and complex patterns can be produced on two films simultaneously irradiating an empty glass cell composed unaligned photocrosslinkable polymer LC three-beam interference beam. The polarization azimuth, ellipticity,...