AI speaker: a scope of utilizing sub–wavelength directional sensing of bio–inspired MEMS directional microphone

Author(s):  
Ashiqur Rahaman ◽  
Byungki Kim
PIERS Online ◽  
2005 ◽  
Vol 1 (1) ◽  
pp. 37-41 ◽  
Author(s):  
Pavel A. Belov ◽  
C. R. Simovski

Nanophotonics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 897-903 ◽  
Author(s):  
Oleksandr Buchnev ◽  
Alexandr Belosludtsev ◽  
Victor Reshetnyak ◽  
Dean R. Evans ◽  
Vassili A. Fedotov

AbstractWe demonstrate experimentally that Tamm plasmons in the near infrared can be supported by a dielectric mirror interfaced with a metasurface, a discontinuous thin metal film periodically patterned on the sub-wavelength scale. More crucially, not only do Tamm plasmons survive the nanopatterning of the metal film but they also become sensitive to external perturbations as a result. In particular, by depositing a nematic liquid crystal on the outer side of the metasurface, we were able to red shift the spectral position of Tamm plasmon by 35 nm, while electrical switching of the liquid crystal enabled us to tune the wavelength of this notoriously inert excitation within a 10-nm range.


2021 ◽  
Vol 197 ◽  
pp. 106308
Author(s):  
Yijie Liu ◽  
Liang Jin ◽  
Hongfa Wang ◽  
Dongying Liu ◽  
Yingjing Liang

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
M. Saad Bin-Alam ◽  
Orad Reshef ◽  
Yaryna Mamchur ◽  
M. Zahirul Alam ◽  
Graham Carlow ◽  
...  

AbstractPlasmonic nanostructures hold promise for the realization of ultra-thin sub-wavelength devices, reducing power operating thresholds and enabling nonlinear optical functionality in metasurfaces. However, this promise is substantially undercut by absorption introduced by resistive losses, causing the metasurface community to turn away from plasmonics in favour of alternative material platforms (e.g., dielectrics) that provide weaker field enhancement, but more tolerable losses. Here, we report a plasmonic metasurface with a quality-factor (Q-factor) of 2340 in the telecommunication C band by exploiting surface lattice resonances (SLRs), exceeding the record by an order of magnitude. Additionally, we show that SLRs retain many of the same benefits as localized plasmonic resonances, such as field enhancement and strong confinement of light along the metal surface. Our results demonstrate that SLRs provide an exciting and unexplored method to tailor incident light fields, and could pave the way to flexible wavelength-scale devices for any optical resonating application.


2021 ◽  
Vol 11 (4) ◽  
pp. 1544
Author(s):  
Meguya Ryu ◽  
Yoshiaki Nishijima ◽  
Shinya Morimoto ◽  
Naoki To ◽  
Tomoki Hashizume ◽  
...  

The four polarisation method is adopted for measurement of molecular orientation in dielectric nanolayers of metal-insulator-metal (MIM) metamaterials composed of gold nanodisks on polyimide and gold films. Hyperspectral mapping at the chemical finger printing spectral range of 4–20 μμm was carried out for MIM patterns of 1–2.5 μμm period (sub-wavelength). Overlay images taken at 0,π4,π2,3π4 orientation angles and subsequent baseline compensation are shown to be critically important for the interpretation of chemical mapping results and reduction of spurious artefacts. Light field enhancement in the 60-nm-thick polyimide (I in MIM) was responsible for strong absorption at the characteristic polyimide bands. Strong absorbance A at narrow IR bands can be used as a thermal emitter (emittance E=1−R), where R is the reflectance and A=1−R−T, where for optically thick samples the transmittance is T=0.


Nanophotonics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 3279-3285 ◽  
Author(s):  
Zhiwei Yan ◽  
Chong Sheng ◽  
Shining Zhu ◽  
Hui Liu

AbstractHow to capture electromagnetic fields into sub-wavelength spatial scales has been a major challenge in nanophotonics, especially confining surface plasmon polaritons into regions as small as a few nanometers. Although various methods are proposed to achieve this goal, these methods require complex fabrication process. Here, we demonstrate experimentally the achievement of nanofocusing of surface plasmon polaritons with an intensity enhancement of three, using the simple structure with just pasting a sliver microwire on a sliver layer. And the designed structure has a well-defined gravitational field inspired by transformation optics. This simple design structure has applications to enhance light–matter interactions, such as nonlinear optical process and Raman scattering.


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