Zobrazeno 1 - 10
of 62
pro vyhledávání: '"Motonobu Tomoda"'
Publikováno v:
Photoacoustics, Vol 34, Iss , Pp 100567- (2023)
By means of an ultrafast optical technique, picosecond acoustic strain pulses in a transparent medium are tomographically visualized at GHz frequencies. The strain distribution in BK7 glass is reconstructed from time-domain reflectivity changes of 41
Externí odkaz:
https://doaj.org/article/4ef0113df830407ebfa923aa623e86d3
Autor:
Takehiro Tachizaki, Jeremy J. Baumberg, Osamu Matsuda, Motonobu Tomoda, Hirotsugu Ogi, Oliver B. Wright
Publikováno v:
Photoacoustics, Vol 34, Iss , Pp 100566- (2023)
We introduce a spectral analysis method in picosecond ultrasonics to derive strain pulse shapes in an opaque sample with known optical properties. The method makes use of both the amplitude and phase of optical transient relative reflectance changes
Externí odkaz:
https://doaj.org/article/9a3d8137c1454aae90fac5f06e95fa49
Publikováno v:
Applied Physics Express, Vol 17, Iss 1, p 017004 (2024)
We construct a two-dimensional mechanical wave machine based on a hexagonal lattice to investigate low-frequency flexural plate waves whose propagation mimicks a topological quantum valley Hall system. We thereby demonstrate “mechanical graphene”
Externí odkaz:
https://doaj.org/article/5965afab96a84a85889cf4fc28e738cc
Publikováno v:
Photoacoustics, Vol 31, Iss , Pp 100486- (2023)
We present a picosecond optoacoustic technique for mapping both the longitudinal sound velocity v and the refractive index n in solids by automated measurement at multiple probe incidence angles in time-domain Brillouin scattering. Using a fused sili
Externí odkaz:
https://doaj.org/article/0aaee06bc3f949eca6b58ee92e80dc3f
Autor:
Osamu Matsuda, Hiroaki Koga, Hiroki Nishita, Motonobu Tomoda, Paul H. Otsuka, Oliver B. Wright
Publikováno v:
Photoacoustics, Vol 30, Iss , Pp 100471- (2023)
We exploit a time-resolved ultrafast optical technique to study the propagation of point-excited surface acoustic waves on a microscopic two-dimensional phononic crystal in the form of a square lattice of holes in a silicon substrate. Constant-freque
Externí odkaz:
https://doaj.org/article/1884e765257e4bcf88ccd0a55f027958
Publikováno v:
Photoacoustics, Vol 30, Iss , Pp 100459- (2023)
Time-domain Brillouin scattering (TDBS) is an all-optical experimental technique for investigating transparent materials based on laser picosecond ultrasonics. Its application ranges from imaging thin-films, polycrystalline materials and biological c
Externí odkaz:
https://doaj.org/article/9c010ded9a32442e9baf5e2dd5d846c3
Autor:
Qingnan Xie, Sylvain Mezil, Paul H. Otsuka, Motonobu Tomoda, Jérôme Laurent, Osamu Matsuda, Zhonghua Shen, Oliver B. Wright
Publikováno v:
Nature Communications, Vol 10, Iss 1, Pp 1-7 (2019)
Zero-group-velocity Lamb waves, which are surface waves with reduced losses and high Q factor, have many potential applications. The authors image such waves in 2 dimensions, and in the GHz range, with a bilayer using a time-resolved imaging techniqu
Externí odkaz:
https://doaj.org/article/2faff5703a904ef681038d18cf7f8b88
Autor:
Paul H Otsuka, Sylvain Mezil, Osamu Matsuda, Motonobu Tomoda, Alexei A Maznev, Tian Gan, Nicholas Fang, Nicholas Boechler, Vitalyi E Gusev, Oliver B Wright
Publikováno v:
New Journal of Physics, Vol 20, Iss 1, p 013026 (2018)
We extend time-domain imaging in acoustic metamaterials to gigahertz frequencies. Using a sample consisting of a regular array of ∼1 μ m diameter silica microspheres forming a two-dimensional triangular lattice on a substrate, we implement an ultr
Externí odkaz:
https://doaj.org/article/9d99884c95f44906899fb5a8ad334a9f
Publikováno v:
AIP Advances, Vol 4, Iss 1, Pp 017124-017124-8 (2014)
We describe an extension of the time-resolved two-dimensional gigahertz surface acoustic wave imaging based on the optical pump-probe technique with periodic light source at a fixed repetition frequency. Usually such imaging measurement may generate
Externí odkaz:
https://doaj.org/article/4d861212ee1b4170ab3f4d00bc8e4e5f
Autor:
Motonobu Tomoda, Shinnosuke Matsueda, Paul H Otsuka, Osamu Matsuda, Istvan A Veres, Vitalyi E Gusev, Oliver B Wright
Publikováno v:
New Journal of Physics, Vol 16, Iss 10, p 103029 (2014)
Using an ultrafast optical technique we image near-gigahertz flexural acoustic waves propagating in a thin gold wedge deposited on an ultrathin silicon nitride slab. Temporal Fourier transforms of the imaged data in two dimensions allow individual fr
Externí odkaz:
https://doaj.org/article/cf5408ecc63d473d91d38efab1a7d0fb