Elliptical metallic rings-shaped fractal metamaterial absorber in the visible regime

Abstract

Achieving the broadband response of metamaterial absorbers has been quite challenging due to the inherent bandwidth limitations. Herein, the investigation was made of a unique kind of visible light metamaterial absorber comprising elliptical rings-shaped fractal metasurface using tungsten metal. It was found that the proposed absorber exhibits average absorption of over 90% in the visible wavelength span of 400-750 nm. The features of perfect absorption could be observed because of the localized surface plasmon resonance that causes impedance matching. Moreover, in the context of optoelectronic applications, the absorber yields absorbance up to ~ 70% even with the incidence obliquity in the range of 0°-60° for transverse electric polarization. The theory of multiple reflections was employed to further verify the performance of the absorber. the obtained theoretical results were found to be in close agreement with the simulation results. in order to optimize the results, the performance was analyzed in terms of the figure of merit and operating bandwidth. Significant amount of absorption in the entire visible span, wide-angle stability, and utilization of low-cost metal make the proposed absorber suitable in varieties of photonics applications, in particular photovoltaics, thermal emitters and sensors. In recent years, optical metamaterials have gained considerable attention in both the engineering and scientific lexicons owing to the exotic electromagnetic (EM) response, that led to varieties of technological applications 1-6. As has been in reports, these artificially engineered materials allow the versatile utility to manipulate the amplitude, phase, and polarization of the incidence radiation at a deep subwavelength scale 7. Metamaterials are generally comprised of nano-resonators, scatterers and meta-molecules of different size, shape, geometry, orientation, and arrangement. Within the context, the negative refractive index (RI)-based metasurfaces enable intriguing applications in super lensing 8 , planar filters 3 , optical cloaking 9,10 , wavefront manipulation 11,12 , optical chirality 13 , medical imaging 14 , and perfect absorption 15-17. These are also tremendously exploited in various other EM applications, namely asymmetric transmission, plasmon-induced transparency, holography, and bio-sensing 6,17-19. Extensive studies have been reported on metamaterial absorbers operating in different frequency regimes 20-22 owing to the prevalent applications in bolometer, holograms, stealth technology, solar energy harvesting, wireless communications, and sensors 15-17,23-27. From the perspective of absorption bandwidth, the narrowband metamaterial absorbers covering the visible and infrared (IR) regimes find applications, such as thermal emission manipulation, nano-antennas, sensors, and resonators 28,29. On the other hand, wideband absorbers have potentials in solar energy converters, artificial colors, thermal emitters, and many other optoelectronic applications 30,31. Within the context, photovoltaics have im...

A Wide-Angle, Enhanced Oblique Incidence, Bend-Able Metamaterial Absorber Employed in Visible Region With a Sun Shape Resonator

“…The resonator in this work has a circular ring in the middle along with eight slotted sectors around the circular ring that allow for wide-angle insensitivity, and the electric fields are entered on the circular ring's edges and the magnetic fields are large at the slotted sectors as shown in Fig. 8 (a-h) and its parameters have been fine-tuned to have the least degree of angle sensitivity possible [55], [57], [58]. This geometric pattern aids the proposed structure to be wide-angle stable in the visible region.…”

Wideband Microwave Absorber Comprising Metallic Split-Ring Resonators Surrounded With E-Shaped Fractal Metamaterial

“…To date, several forms of PMAs have been reported for suitably operating in the microwave, terahertz, visible and ultraviolet regimes [13], [30]- [32]. The desired absorption band can be essentially achieved by tailoring/optimizing the geometric parameters of the constituent meta-atoms (or the unit cells).…”

“…However, the drawbacks, such as large size, fabrication complexities, and high cost, very often suffice. Some other techniques exploit the use of slot-loading [33], frequency selective surfaces [34] and fractals [21], [32], [35]. It remains rather challenging to achieve broadband absorption with the use of a single metasurface layer in designing PMAs.…”

Broadband Vibration Attenuation Achieved by 2D Elasto-Acoustic Metamaterial Plates with Rainbow Stepped Resonators

“…Metamaterials were first described in the area of electromagnetic wave control [1][2][3]. Many electromagnetic and optical metamaterials were proposed with unusual properties such as negative refractive index [4][5][6], negative permittivity [7,8], broadband absorption [9], etc. In the past two decades, the concept of metamaterials has been extended to the areas of acoustic and elastic wave control.…”