scholarly journals Hyperspectral Molecular Orientation Mapping in Metamaterials

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 ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 823-832 ◽  
Author(s):  
Amir Ghobadi ◽  
Hodjat Hajian ◽  
Murat Gokbayrak ◽  
Bayram Butun ◽  
Ekmel Ozbay

AbstractIn recent years, sub-wavelength metamaterials-based light perfect absorbers have been the subject of many studies. The most frequently utilized absorber configuration is based on nanostructured plasmonic metals. However, two main drawbacks were raised for this design architecture. One is the fabrication complexity and large scale incompatibility of these nano units. The other one is the inherent limitation of these common metals which mostly operate in the visible frequency range. Recently, strong interference effects in lithography-free planar multilayer designs have been proposed as a solution for tackling these drawbacks. In this paper, we reveal the extraordinary potential of bismuth (Bi) metal in achieving light perfect absorption in a planar design through a broad wavelength regime. For this aim, we adopted a modeling approach based on the transfer matrix method (TMM) to find the ideal conditions for light perfect absorption. According to the findings of our modeling and numerical simulations, it was demonstrated that the use of Bi in the metal-insulator-metal-insulator (MIMI) configuration can simultaneously provide two distinct functionalities; a narrow near unity reflection response and an ultra-broadband near perfect absorption. The reflection behavior can be employed to realize additive color filters in the visible range, while the ultra-broadband absorption response of the design can fully harvest solar irradiation in the visible and near infrared (NIR) ranges. The findings of this paper demonstrate the extraordinary potential of Bi metal for the design of deep sub-wavelength optical devices.


Micromachines ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 157 ◽  
Author(s):  
Atsushi Sakurai ◽  
Yuki Matsuno

In this study, a tungsten-SiO2-based metal–insulator–metal-structured metasurface for the thermal emitter of the thermophotovoltaic system was designed and fabricated. The proposed emitter was fabricated by applying the photolithography method. The fabricated emitter has high emissivity in the visible to near-infrared region and shows excellent wavelength selectivity. This spectral emissivity tendency agreed well with the result calculated by the finite-difference time-domain method. Additionally, the underlying mechanism of its emission was scrutinized. Study of the fabrication process and theoretical mechanisms of the emission, clarified in this research, will be fundamental to design the wavelength-selective thermal emitter.


2020 ◽  
Vol 8 (18) ◽  
pp. 2000609
Author(s):  
Angelica Carrara ◽  
Nicolò Maccaferri ◽  
Andrea Cerea ◽  
Angelo Bozzola ◽  
Francesco De Angelis ◽  
...  

2009 ◽  
Vol 17 (13) ◽  
pp. 11107 ◽  
Author(s):  
Martin T. Hill ◽  
Milan Marell ◽  
Eunice S. P. Leong ◽  
Barry Smalbrugge ◽  
Youcai Zhu ◽  
...  

2011 ◽  
Author(s):  
Terrance O'Regan ◽  
Matthew Chin ◽  
Cheng Tan ◽  
Anthony Birdwell

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 4 (3) ◽  
pp. 2470-2475 ◽  
Author(s):  
Ayendra Weerakkody ◽  
Amina Belkadi ◽  
Garret Moddel

2019 ◽  
Vol 9 (4) ◽  
pp. 644
Author(s):  
Xue-Shi Li ◽  
Naixing Feng ◽  
Yuan-Mei Xu ◽  
Liang-Lun Cheng ◽  
Qing Liu

A tunable demultiplexer with three output channels infiltrated by liquid crystal (LC) is presented, which is based on a metal-insulator-metal (MIM) waveguide. The operating frequencies of the three output channels can be tuned simultaneously at will by changing the external bias electric field applied to the LC. By analyzing the Fabry-Pérot (FP) resonance modes of the finite-length MIM waveguide both theoretically and numerically, the locations of the three channels are delicately determined to achieve the best demultiplexing effects. Terahertz (THz) signals input from the main channel can be demultiplexed by channels 1, 2 and 3 at 0.7135 THz, 1.068 THz and 1.429 THz, respectively. By applying an external electric field to alter the tilt angle of the infiltrating LC material, the operating frequencies of channels 1, 2 and 3 can be relatively shifted up to 12.3%, 9.6% and 9.7%, respectively. The designed demultiplexer can not only provide a flexible means to demultiplex signals but also tune operating bands of output channels at the same time.


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