arXiv subjects

Teruya Ishihara

Publications and source records attributed to Teruya Ishihara.

7 recordsLinked to original sources

arXiv2017

Polarization dependence of transverse photo-induced voltage in gold thin film with random nanoholes

Transverse photo-induced voltage (TPIV) in 25nm-thick Au film with random holes with 100 nm in diameter is measured for linearly, circularly and elliptically polarized light. By rotating the major axis of ellipse of the light, TPIV exhibits specific pattern depending on polarization. The experimental results are readily reproduced by assuming that the angular momentum transfer from the light beam to the film is responsible for TPIV. A novel ellipticity meter is proposed based on this mechanism.

physics.optics↗

arXiv2016

Quasi-analytical solutions of hybrid platform and the optimization of highly sensitive thin-film sensors for terahertz radiation

We present quasi-analytical solutions (QANS) of hybrid platform (HP) comprising metallic grating (MG) and stacked-dielectric layers for terahertz (THz) radiation. The QANS are validated by finite difference time domain simulation. It is found that the Wood anomalies induce the high-order spoof surface plasmon resonances in the HP. The QANS are applied to optimize new perfect absorber for THz sensing of large-area thin film with ultrahigh figure of merit reaching fifth order of magnitude for the film thickness 0.0001p (p: MG period). The first-order Wood's anomaly of the insulator layer and the Fabry-Perot in the slit's cavity account for the resonance of the perfect absorber. The QANS and the new perfect absorber may lead to highly sensitive and practical nano-film refractive index sensor for THz radiation.

physics.optics↗

arXiv2015

Photo-induced voltage in nano-porous gold thin film

We report an experimental study of generation of photo-induced voltage in nano-porous gold (NPG) thin film under the radiation of obliquely incident nanosecond laser light in visible regions. For s- polarized light, negative voltage is observed along the incident plane for positive incident angles, while for p- polarized light, positive voltage is observed for wavelength longer than 510 nm, while it turns to negative for shorter wavelengths. The transverse voltage for various polarized light is explained in terms of symmetry of configuration and that of microscopically random but macroscopically isotropic NPG.

cond-mat.mtrl-sci↗

arXiv2014

Waveguide-mode interference lithography technique for high contrast subwavelength structures in the visible region

We explore possibilities of waveguide-mode interference lithography (WMIL) technique for high contrast subwavelength structures in the visible region. Selecting an appropriate waveguide-mode, we demonstrate high contrast resist mask patterns for the first time. TM1 mode in the waveguide is shown to be useful for providing a three-dimensional structure whose cross section is checkerboard pattern. Applying our WMIL technique, we demonstrate 1D, 2D and 3D subwavelength resist patterns that are widely used for the fabrication of metamteterials in the visible region. In addition to the resist patterns, we demonstrate a resonance at 1.9 eV for a split tube structure experimentally.

physics.optics↗

arXiv2009

Transverse Photo-Voltage Induced by Circularly Polarized Light

We discovered that when circularly polarized light is obliquely incident on a two-dimensional metallic photonic crystal slabs, electrical voltage is induced perpendicularly to the incident plane. Signal sign is reversed by changing the sense of polarization or incident angle. The origin of this transverse photo-induced voltage is explained in terms of the force linear in light intensity induced by the asymmetry brought by angular momentum of incident light.

physics.optics↗

arXiv2007

Reciprocal transmittances and reflectances: An elementary proof

We present an elementary proof concerning reciprocal transmittances and reflectances. The proof is direct, simple, and valid for the diverse objects that can be absorptive and induce diffraction and scattering, as long as the objects respond linearly and locally to electromagnetic waves. The proof enables students who understand the basics of classical electromagnetics to grasp the physical basis of reciprocal optical responses. In addition, we show an example to demonstrate reciprocal response numerically and experimentally.

physics.optics↗

arXiv2005

Full optical responses of one-dimensional metallic photonic crystal slabs

We reveal all the linear optical responses, reflection, transmission, and, diffraction, of typical one-dimensional metallic photonic crystal slabs (MPhCS) with the periodicity of a half micrometer. Maxwell equations for the structure of deep grooves are solved numerically with good precision by using the formalism of scattering matrix, without assuming perfect conductivity. We verify characteristic optical properties such as nearly perfect transmission and reflection. Moreover, we present large reflective diffraction and show that, in the energy range where diffraction channels are open, the photonic states in the MPhCS originate from surface plasmon polaritons.

cond-mat.mtrl-sci↗