2017 Fiscal Year Annual Research Report
Subwavelength acoustic imaging using kHz-GHz extraordinary transmission
| Project/Area Number |
16F16786
|
|---|
| Research Institution | Hokkaido University |
|---|
Principal Investigator |
O・B Wright 北海道大学, 工学研究院, 教授 (90281790)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
DEVAUX THIBAUT 北海道大学, 工学(系)研究科(研究院), 外国人特別研究員
|
|---|
| Project Period (FY) |
2016-11-07 – 2019-03-31
|
| Keywords | extraordinary / transmission / metamaterial / audio / ultrasonics / sound |
|---|
| Outline of Annual Research Achievements |
We have demonstrated an Extraordinary-Transmission (ET)-based scanning acoustic microscope based on membrane resonance (MR) in the audio (up to 20 kHz) range (wavelength ~1-10 mm) with deeply sub-wavelength (<lamba/30) resolution. The microscope has a plastic membrane of diameter around 1 cm working at around 1000 Hz. We confirmed operation for topography measurement up to 15 mm distance. Linear scans were made of several materials to confirm lambda/20 resolution. We have also done simulations on GHz ET of longitudinal waves in nanoscale silicon bridges and confirmed the principle works with grooves at the input side. Similar simulations of GHz ET for surface acoustic waves have also been successful.
|
| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
Last year we demonstrated an Extraordinary-Transmission (ET)-based scanning acoustic microscope based on membrane resonance (MR) in the audio (up to 20 kHz) range (wavelength ~1-10 mm) with deeply sub-wavelength (<lamba/30) resolution. The microscope has a plastic membrane of diameter around 1 cm working at around 1000 Hz. We extended this work by making 2D images of two different structures: 1) a triangular sample of rubber less than 1 mm thick, and 2) a wooden cross about 10 mm thick. We confirmed operation for topography measurement up to 15 mm distance. We also confirmed lambda/300 resolution in the vertical direction and around lambda/20 resolution in the lateral direction, where lambda is the acoustic wavelength. We are also developing an analytical model of the microscope based on lumped impedances. We are in the process of writing a paper on these results.
|
| Strategy for Future Research Activity |
We have also continued to do simulations on GHz ET of longitudinal waves in nanoscale silicon bridges and with grooves at the input or output side. We optimized the groove geometry to obtain a very high value of the transmission efficiency >100, surpassing our previous results for surface waves in similar silicon bridge structures. We in the process of writing a journal paper on these results.
|
-
-
-
-
-
[Presentation] Extraordinary transmission of GHz bulk acoustic waves2017
Author(s)
T. Devaux, H. Tozawa, M. Tomoda, P. H. Otsuka, S. Mezil, O. Matsuda, I. A. Veres, and O. B. Wright
Organizer
META’17, the 8th International Conference on Metamaterials, Photonic Crystals and Plasmonics, Incheon, Korea
Int'l Joint Research
-
-
-
-
