Visible light nearly perfect absorber: an optimum unit cell arrangement for near absolute polarization insensitivity

Ghobadi, Amir; Hajian, Hodjat; Gokbayrak, Murat; Dereshgi, Sina Abedini; Toprak, Ahmet; Bütün, Bayram; Özbay, Ekmel

doi:10.1364/oe.25.027624

Cited by 80 publications

(57 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…at d i =80 nm). In such a case, the field pattern is similar to the one in [17]. At the same time, as will be exemplified below for our optimal parameters, a GMR can dominate at larger thicknesses of the dielectric layer.…”

Section: Physical Analysissupporting

confidence: 53%

“…There are two absorption peaks at 477 and 783 nm, which almost perfectly match with the first and second absorption peaks of the main structure at 478 and 778 nm, respectively. This indicates that, in contrast with some of the earlier suggested absorbers [16,17], these peaks are mainly not due to the excitation of a PSP mode at the bottom Al 2 O 3 -Ti interface. Indeed, when there is a PEC at the bottom layer, any PSP mode cannot exist.…”

Section: Physical Analysismentioning

confidence: 58%

“…The absorption peaks may be due to different types of resonances such as LSP, PSP, or guided-mode resonance (GMR). The LSP resonances can occur because of the existence of nanodisks [16], the PSP mode can propagate in the continuous interface of the bottom Ti and Al 2 O 3 layer [17], and GMR can appear in the Al 2 O 3 layer that can work as a dielectric waveguide starting from a certain value of d i [45][46][47]. It is noteworthy that, as follows from the results of simulations performed for different materials of dielectric (i.e.…”

Section: Physical Analysismentioning

confidence: 90%

See 2 more Smart Citations

A Route to Unusually Broadband Plasmonic Absorption Spanning from Visible to Mid-infrared

et al. 2019

Self Cite

View full text Add to dashboard Cite

In this paper, a route to ultra-broadband absorption is suggested and demonstrated by a feasible design. The high absorption regime (absorption above 90%) for the suggested structure ranges from visible to mid-infrared (MIR), i.e. for the wavelength from 478 to 3,278 nm that yields an ultra-wide bandwidth of 2,800 nm. The structure consists of a top-layer-patterned metal-insulator-metal (MIM) configuration, into the insulator layer of which, an ultra-thin 5 nm layer of Manganese (Mn) is embedded. The MIM configuration represents a Ti-Al 2 O 3 -Ti tri-layer. It is shown that, without the ultra-thin layer of Mn, the absorption bandwidth is reduced to 274 nm. Therefore, adding only a 5 nm layer of Mn leads to a more than tenfold increase in the width of the absorption band. It is explained in detail that the physical mechanism contributing to this ultra-broadband result is a combination of plasmonic and non-plasmonic resonance modes, along with the appropriate optical properties of Mn. This structure has the relative bandwidth (RBW) of 149%, while only one step of lithography is required for its fabrication, so it is relatively simple to fabricate. This makes it rather promising for practical applications.

show abstract

Section: Physical Analysissupporting

confidence: 53%

Section: Physical Analysismentioning

confidence: 58%

Section: Physical Analysismentioning

confidence: 90%

See 1 more Smart Citation

A Route to Unusually Broadband Plasmonic Absorption Spanning from Visible to Mid-infrared

et al. 2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…The initial designs in the literature lacked mechanisms to trap the EMWs inside the structure and, consequently, EMWs were not fully harvested and they achieved a low bandwidth . Confinement of EMWs inside the structure was achieved by introducing a new architecture that is a metal–insulator—metal (MIM) cavity design with patterned top layers . These configurations are based on the cancellation of EMWs that move in the upward and downward directions between two metallic layers.…”

Section: Introductionmentioning

confidence: 99%

“…[6,7] Confinement of EMWs inside the structure was achieved by introducing a new architecture that is a metal-insulator-metal (MIM) cavity design with patterned top layers. [8][9][10][11][12][13][14][15][16][17] These configurations are based on the cancellation of EMWs that move in the upward and downward directions between two metallic layers. However, they necessitate a complex fabrication route due to requiring electron-beam lithography (EBL).…”

mentioning

confidence: 99%

Lithography‐Free Random Bismuth Nanostructures for Full Solar Spectrum Harvesting and Mid‐Infrared Sensing

Soydan

Ghobadi

Yıldırım

et al. 2019

Advanced Optical Materials

Self Cite

View full text Add to dashboard Cite

A lithography‐free, double‐functional single bismuth (Bi) metal nanostructure is designed, fabricated, and characterized for ultrabroadband absorption in the visible (vis) and near‐infrared (NIR) ranges, and for a narrowband response with ultrahigh refractive index sensitivity in the mid‐infrared (MIR) range. To achieve a large‐scale fabrication of the design in a lithography‐free route, the oblique‐angle deposition approach is used to obtain densely packed and randomly spaced/oriented Bi nanostructures. It is shown that this fabrication technique can provide a bottom‐up approach to controlling the length and spacing of the design. The characterization findings reveal a broadband absorbance above 0.8 in vis and NIR, and a narrowband absorbance centered around 6.54 µm. Dense architecture and extraordinary permittivity of Bi provide strong field confinement in ultrasmall gaps between nanostructures, and this can be utilized for a sensing application. An ultrahigh sensitivity of 2151 nm refractive‐index unit (RIU–1) is acquired, which is, as far as it is known, the experimentally highest sensitivity attained so far. The simple and large‐scale compatible fabrication route of the design together with the extraordinary optical response of Bi coating makes this design promising for many optoelectronic and sensing applications.

show abstract

A Broadband Plasmonic Metasurface Superabsorber at Optical Frequencies: Analytical Design Framework and Demonstration

Nagarajan

Kumar

Shah

et al. 2018

Advanced Optical Materials

View full text Add to dashboard Cite

Metasurface based superabsorbers exhibit near unity absorbance. While the absorption peak can be tuned by the geometry/size of the sub-wavelength resonator, broadband absorption can be obtained by placing multiple resonators of various size/shapes in a unit cell.Metal dispersion hinders high performance broadband absorption at optical frequencies and careful designing is essential to achieve good structures. We propose a novel analytical framework for designing a broadband superabsorber which is much faster than the time consuming full wave simulations that are employed so far. Analytical expressions are derived for the wavelength dependency of the design parameters, which are then used in the optimization of broadband absorption. Numerical simulations report an average polarizationindependent absorption of ~97% in the 450 -950 nm spectral region with a near unity absorption (99.36%) in the 500 -850 nm region. Experimentally, we demonstrate an average absorption over 98% in the 450-950 nm spectral region at 20° incident angle The designed superabsorber is polarization insensitive and has a weak launch angle dependency. The proposed framework simplifies the design process and provides a quicker optimal solution for high performance broadband superabsorbers

show abstract

Visible light nearly perfect absorber: an optimum unit cell arrangement for near absolute polarization insensitivity

Cited by 80 publications

References 36 publications

A Route to Unusually Broadband Plasmonic Absorption Spanning from Visible to Mid-infrared

A Route to Unusually Broadband Plasmonic Absorption Spanning from Visible to Mid-infrared

Lithography‐Free Random Bismuth Nanostructures for Full Solar Spectrum Harvesting and Mid‐Infrared Sensing

A Broadband Plasmonic Metasurface Superabsorber at Optical Frequencies: Analytical Design Framework and Demonstration

Contact Info

Product

Resources

About