Tailoring Metal and Insulator Contributions in Plasmonic Perfect Absorber Metasurfaces

2018 ◽  
Author(s):  
Yoshiaki Nishijima ◽  
Armandas Balcytis ◽  
Shin Naganuma ◽  
Gediminas Seniutinas ◽  
Saulius Juodkazis
Keyword(s):  
Electrical Conductivity ◽  
Optical Properties ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Perfect Absorber ◽  
Mid Infrared ◽  
Plasma Sputtering ◽  
Absorption Of Light ◽  
Fdtd Simulations ◽  
Difference Time

<div>Maximum absorption of light using plasmonic perfect absorbers (PPAs) is highly desired in the field of energy harvesting. We reveal how optical properties of several</div><div>popular metals and insulators are affecting performance of PPAs at mid-infrared (IR) wavelengths. Optical properties of experimentally prepared (by plasma sputtering) structures follow expected scalings, however, departure from the finite difference time domain (FDTD) simulations are significant when roughness of the first metal baselayer is not taken into account. Electrical conductivity is shown to strongly affect</div><div>performance of PPAs.</div>

Tailoring Metal and Insulator Contributions in Plasmonic Perfect Absorber Metasurfaces

2018 ◽  
Author(s):  
Yoshiaki Nishijima ◽  
Armandas Balcytis ◽  
Shin Naganuma ◽  
Gediminas Seniutinas ◽  
Saulius Juodkazis
Keyword(s):  
Electrical Conductivity ◽  
Optical Properties ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Perfect Absorber ◽  
Mid Infrared ◽  
Plasma Sputtering ◽  
Absorption Of Light ◽  
Fdtd Simulations ◽  
Difference Time

<div>Maximum absorption of light using plasmonic perfect absorbers (PPAs) is highly desired in the field of energy harvesting. We reveal how optical properties of several</div><div>popular metals and insulators are affecting performance of PPAs at mid-infrared (IR) wavelengths. Optical properties of experimentally prepared (by plasma sputtering) structures follow expected scalings, however, departure from the finite difference time domain (FDTD) simulations are significant when roughness of the first metal baselayer is not taken into account. Electrical conductivity is shown to strongly affect</div><div>performance of PPAs.</div>

Thermal Radiative Properties of Vertical Graphitic Petal Arrays

2012 ◽  
Author(s):  
Bhagirath Duvvuri ◽  
Anurag Kumar ◽  
Hua Bao ◽  
Haoxiang Huang ◽  
Timothy Fisher ◽  
...  
Keyword(s):  
Optical Properties ◽  
Electric Field ◽  
Finite Difference Time Domain ◽  
Incident Radiation ◽  
Radiative Properties ◽  
Thermal Radiative Properties ◽  
Fdtd Simulations ◽  
Difference Time ◽  
Graphitic Plane ◽  
Very High

In this work, thermal radiative properties of vertical graphene petal arrays are theoretically and experimentally investigated to show that they are superior absorbers of radiation. Finite difference time domain (FDTD) simulations are first performed to calculate optical properties of vertical graphitic arrays of different configurations, namely, graphitic gratings, periodic graphitic cavities, and random graphitic cavities. The effect of polarization of incident radiation on optical properties of such structures is systematically evaluated. When the incident electric field is parallel to the graphitic plane (S polarization) in graphitic gratings, the absorptance is very high, but the reflectance low but still significant when compared to reflectance from a MWCNT array. On the other hand, when the electric field is polarized perpendicular to the graphitic plane (P polarization), the absorptance is significantly lower, as well as the reflectance. This contrast is due to the stronger optical response for the S polarization. Ordered graphitic petal cavity arrays show optical properties falling between the above two cases because of the presence of both polarizations. The random graphitic petal cavity arrays with various angles of orientation show similar properties with ordered petal arrays, and the simulated reflectance agrees very well with experimental data measured on a fabricated thin graphite petal sample.

STUDY ON A SORT OF CONTROLLABLE NONLINEAR LEFT-HANDED MATERIALS

2009 ◽  
Vol 18 (03) ◽  
pp. 441-456 ◽  
Author(s):  
HONG XIN ZHANG ◽  
LAN ZHAO ◽  
YING HUA LU
Keyword(s):  
Resonance Frequency ◽  
Time Domain ◽  
Material Properties ◽  
Finite Difference Time Domain ◽  
Transmission Properties ◽  
The Past ◽  
Left Handed ◽  
High Harmonics ◽  
Fdtd Simulations ◽  
Difference Time

In this paper, three kinds of controllable nonlinear left-handed materials (DNLHMs) are proposed and analyzed, which are designed by introducing inductors and capacitors into the traditional nonlinear left-handed materials (NLHMs) as inhomogeneous doped elements. Due to such changes, several new transmission properties have been presented through finite-difference time-domain (FDTD) simulations. These have brought new features to our DNLHMs. On one hand, the original passband in the traditional nonlinear left-handed material is narrowed after introducing inductors. In addition, a new passband, which does not exist in doped linear LHMs, is generated. On the other hand, through introducing capacitors, the original passband of the nonlinear left-handed material can be shifted, resonance frequency can be changed, and a new passband can be generated. When capacitors and inductors are introduced simultaneously, the material properties, such as the number of passbands, the characteristic resonance frequency, and the bandwidth, can also be changed. Noting these characteristics, the values of the introduced inductors and capacitors are varied to investigate the spectrum changes of DNLHMs. Then, a series of controllable properties of the DNLHMs can be retrieved. And more importantly, the designed DNLHMs give the adjustability of suppressing high harmonics, which is not possible in the past materials.

Design and Analysis of Self-Collimation-Based Photonic Crystal Beam Splitter

2014 ◽  
Vol 887-888 ◽  
pp. 417-421
Author(s):  
Hong Jing Li ◽  
Li An Chen
Keyword(s):  
Photonic Crystal ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Beam Splitter ◽  
Practical Applications ◽  
Beam Splitters ◽  
Output Surface ◽  
Fdtd Simulations ◽  
Two Dimensional Photonic Crystal ◽  
Difference Time

We present a self-collimation-based beam splitter in a two-dimensional photonic crystal (2D-PC) by introducing defects near the termination. From the equi-frequency contour (EFC) calculations and the finite-difference time-domain (FDTD) simulations, we show that the defects can give rise to the splitting of self-collimated beams in 2D-PCs and the directivity of the deflected beam can be improved by the defect along the PC surface. In order to get different kinds of beam splitters, including the Y-shaped, one-to-three, one-to-four structures, and so on, we only need to modify the structure of the output surface (along X-M direction). The proposed splitter may have practical applications in integrated photonic circuits.

Finite-Difference Time-Domain Simulation of Microwave Sintering in A Variable-Frequency Multimode Cavity

1996 ◽  
Vol 430 ◽  
Author(s):  
Mikel J White ◽  
Steven F. Dillon ◽  
Magdy F. Iskander ◽  
Hal D. Kimrey
Keyword(s):  
Finite Difference ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Microwave Sintering ◽  
Single Frequency ◽  
Frequency Variation ◽  
Variable Frequency ◽  
Frequency Range ◽  
Fdtd Simulations ◽  
Difference Time

AbstractThere have been recent indications that variable-frequency microwave sintering of ceramics provides several advantages over single-frequency sintering, including more uniform heating, particularly for larger samples. The Finite-Difference Time-Domain (FDTD) code at the University of Utah was modified and used to simulate microwave sintering using variable frequencies and was coupled with a heat-transfer code to provide a dynamic simulation of this new microwave sintering process. This paper summarizes results from the FDTD simulations of sintering in a variable-frequency cavity. FDTD simulations were run in 100-MHz steps to account for the frequency variation in the electromagnetic fields in the multimode cavity. It is shown that a variable-frequency system does improve the heating uniformity when the proper frequency range is chosen. Specifically, for a single ceramic sample (4 × 4 × 6 cm3), and for a variable-frequency range from f = 2.5 GHz to f = 3.2 GHz, the temperature distribution pattern was much more uniform than the heating pattern achieved when using a single-frequency sintering system at f = 2.45 GHz.

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