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 * ABSTRACT
 * DATA AVAILABILITY
 * REFERENCES

LIGHT ABSORPTION AND NANOFOCUSING ON A TAPERED MAGNETIC METASURFACE

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Open Submitted: 20 August 2020 Accepted: 30 November 2020 Published Online: 14
December 2020
 * LIGHT ABSORPTION AND NANOFOCUSING ON A TAPERED MAGNETIC METASURFACE
 * 


Appl. Phys. Lett. 117, 243102 (2020); https://doi.org/10.1063/5.0026073
Dong Wei1,2, Chai Hu1,2,3, Mingce Chen1,2, Jiashuo Shi1,2, Jun Luo1,2, Haiwei
Wang4, Changsheng Xie4,a), and Xinyu Zhang1,2,a)
more...View Affiliations
 * 1National Key Laboratory of Science and Technology on Multispectral
   Information Processing, Huazhong University of Science and Technology, Wuhan
   430074, China
 * 2School of Artificial Intelligence and Automation, Huazhong University of
   Science and Technology, Wuhan 430074, China
 * 3Innovation Institute, Huazhong University of Science and Technology, Wuhan
   430074, China
 * 4Wuhan National Laboratory for Optoelectronics, Huazhong University of
   Science and Technology, Wuhan 430074, China
 * a)Authors to whom correspondence should be addressed: cs_xie@mail.hust.edu.cn
   and x_yzhang@hust.edu.cn

   Note: This Paper is part of the APL Special Collection on Metastructures:
   From Physics to Applications.

View Contributors
 * Dong Wei
 * Chai Hu
 * Mingce Chen
 * Jiashuo Shi
 * Jun Luo
 * Haiwei Wang
 * Changsheng Xie
 * Xinyu Zhang




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 * Topics
   * Special Topics
     * Metastructures: From Physics to Application
   * Topics
     * Thin films
     * Wave propagation
     * Magnetic devices
     * Reflectivity spectra
     * Surface plasmon polaritons
     * Nanolithography
     * Reflection spectroscopy
     * Metamaterials

ABSTRACT

A type of metasurface was constructed on a silicon wafer using a nanopatterned
magnetic film to achieve ideal light absorption within a wide wavelength range
of 3 μm–15 μm. Using the metasurface, the surface electrons could be localized
efficiently into an arrayed planar magnetic nanotip and then modulated by
configuring the surface architecture to produce remarkable infrared reflectivity
variation. A theoretical analysis showed that the excited surface plasmon
exhibit stronger electric field components at the common metal-to-air interface.
The Tb14Fe68Co18 nanotip array provided more powerful nanofocusing and a lower
infrared reflectivity than an array shaped on a traditional aluminum film. By
adjusting the structural parameters of the nanorhombus array formed on the TbCo
film system, the convergent light spot could be modulated to improve light
absorption markedly.
Surface plasmons, which are surface resonance electromagnetic wavefields, are
closely coupled with surface electron density waves. The latter are stimulated
by incident light waves that fall over a nanostructured interface. This
relationship provides a feasible approach to adjusting the incident light
reflectivity by establishing a patterned surface conductive electron
distribution. This enables the determination of many unique properties, such as
subwavelength light focusing characteristics, near-field light resonance
enhancement, and surface dielectric sensitivity.1–31. E. Cubukcu, N. Yu, E. J.
Smythe, L. Diehl, K. B. Crozier, and F. Capasso, IEEE J. Sel. Top. Quantum
Electron. 14, 1448 (2008). https://doi.org/10.1109/JSTQE.2007.9127472. N. Liu,
M. L. Tang, M. Hentschel, H. Giessen, and A. P. Alivisatos, Nat. Mater. 10, 631
(2011). https://doi.org/10.1038/nmat30293. D. K. Gramotnev and S. I.
Bozhevolnyi, Nat. Photonics 8, 14 (2014).
https://doi.org/10.1038/NPHOTON.2013.232 The plasmonic effect has been applied
to fields such as super-high resolution imaging, optical absorbers, photothermal
effect applications, and spectral filtering,4–64. C. Wu, B. Neuner, G. Shvets,
J. John, A. Milder, B. Zollars, and S. Savoy, Phys. Rev. B 84, 075102 (2011).
https://doi.org/10.1103/PhysRevB.84.0751025. F. Yi, H. Zhu, J. C. Reed, and E.
Cubukcu, Nano Lett. 13, 1638 (2013). https://doi.org/10.1021/nl400087b6. R.
Bardhan, S. Lal, A. Joshi, and N. J. Halas, Acc. Chem. Res. 44, 936 (2011).
https://doi.org/10.1021/ar200023x as well as polarization control and phase
manipulation.7–97. N. Yu and F. Capasso, Nat. Mater. 13, 139 (2014).
https://doi.org/10.1038/nmat38398. D. Franklin, Y. Chen, A. Vazquez-Guardado, S.
Modak, J. Boroumand, D. Xu, S.-T. Wu, and D. Chanda, Nat. Commun. 6, 7337
(2015). https://doi.org/10.1038/ncomms83379. H. Cheng, S. Q. Chen, P. Yu, X. Y.
Duan, B. Y. Xie, and J. G. Tian, Appl. Phys. Lett. 103, 203112 (2013).
https://doi.org/10.1063/1.4831776 Quite recently, magnetic resonance modes
excited on the metasurface have also been studied. For example, magnetic modes
excited on colloidally synthesized sliver nanocubes situated over a gold
film,1010. G. M. Akselrod, J. Huang, T. B. Hoang, P. T. Bowen, L. Su, D. R.
Smith, and M. H. Mikkelsen, Adv. Mater. 27, 8028 (2015).
https://doi.org/10.1002/adma.201503281 as well as a patterned silicon
metasurface has been shown to enhance the absorption greatly.1111. P. D.
Terekhov, K. V. Baryshnikova, Y. Greenberg, Y. H. Fu, A. B. Evlyukhin, A. S.
Shalin, and A. Karabchevsky, Sci. Rep. 9, 3438 (2019).
https://doi.org/10.1038/s41598-019-40226-0 In fact, it has also been shown that
the magnetic mode excited in the metal/insulation/metal metasurface can control
the thermal emission of photons.1212. X. Zhang, H. Lou, Z. G. Zhang, Q. Wang,
and S. N. Zhu, Sci. Rep. 7, 41858 (2017). https://doi.org/10.1038/srep41858
Research on the generation of desired micro-nano-light fields using the
plasmonic effect that has been observed over magnetic materials remains limited.
In this paper, we report a study of surface plasmons excited over magnetic film
surfaces. Enhanced incident light absorption and near-field light nanofocusing
efficiencies are also presented. Theoretical derivations indicate that the wave
vector of a surface resonance wave is larger and the electric field component is
much stronger over a magnetic-to-dielectric interface than over a common
metal–dielectric interface. This leads to more powerful light focusing with a
subwavelength focus and a stronger light absorption. Two different magnetic
films, namely, Tb14Fe68Co18 and TbCo, are studied carefully for efficient
control of infrared reflectivity and near-field light nanofocusing. Nanotips are
fabricated over both the Tb14Fe68Co18 film and a common aluminum film. Upon
comparing the optical properties of the patterned Tb14Fe68Co18 film with those
of the patterned aluminum film, it is found that the infrared reflectivity of
the nanopatterned magnetic film is lower than that of the original metallic
material. In addition, the near-field light can be focused more efficiently
using nanostructured arrays. This results in an improved nanofocusing ability.
The relationships between the optical properties of the structural parameters
were studied using nanopatterned TbCo films. Fabricating a nanorhombus array
over a TbCo film decreased the infrared reflectivity markedly relative to an
un-patterned film. Varying the nanorhombus structural parameters lead to clear
changes in the size and intensity of the near-field light spot formed.
Since the relative magnetic permeability of the magnetic media is not equal to
one, a relatively strong magnetic response represented by the magnetization M is
expected. The propagation constant β, the wave-vector k2, and the electric field
component perpendicular to the magnetic-to-dielectric interface can be
calculated via Maxwell's equations
𝐻𝑦(𝑧)=𝐴2𝑒𝑖𝛽𝑥𝑒−𝑘2𝑧,Hyz=A2eiβxe−k2z,
(1)

𝐸𝑥(𝑧)=𝑖𝐴21𝜔𝜀0𝜀2𝑘2𝑒𝑖𝛽𝑥𝑒−𝑘2𝑧,Exz=iA21ωε0ε2k2eiβxe−k2z,
(2)

𝐸𝑧(𝑧)=−𝐴2𝛽𝜔𝜀0𝜀2𝑒𝑖𝛽𝑥𝑒−𝑘2𝑧,Ezz=−A2βωε0ε2eiβxe−k2z,
(3)

𝛽=𝑘0𝜀1𝜀2𝜀1+𝜀2𝜀1𝜇2−𝜀2𝜇1𝜀1−𝜀2⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯√,β=k0ε1ε2ε1+ε2ε1μ2−ε2μ1ε1−ε2,
(4)

𝑘22=−𝑘20𝜀22𝜀1+𝜀2𝜀1𝜇1−𝜀2𝜇2𝜀1−𝜀2.k22=−k02ε22ε1+ε2ε1μ1−ε2μ2ε1−ε2.
(5)

In a nonmagnetic medium, these components can be represented at the
metal-to-dielectric interface using
𝛽=𝑘0𝜀1𝜀2𝜀1+𝜀2⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯√,β=k0ε1ε2ε1+ε2,
(6)

𝑘22=−𝑘20𝜀22𝜀1+𝜀2.k22=−k02ε22ε1+ε2.
(7)

The propagation constant β is 𝜀1𝜇2−𝜀2𝜇1𝜀1−𝜀2⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯√ε1μ2−ε2μ1ε1−ε2
larger than when nonmagnetic media are used. The component of the wave-vector k2
in the propagation direction is
𝜀1𝜇1−𝜀2𝜇2𝜀1−𝜀2⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯√ε1μ1−ε2μ2ε1−ε2 larger than in the case of
nonmagnetic media. Since both parameters
𝜀1𝜇1−𝜀2𝜇2𝜀1−𝜀2⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯√ε1μ1−ε2μ2ε1−ε2 and
𝜀1𝜇2−𝜀2𝜇1𝜀1−𝜀2⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯√ε1μ2−ε2μ1ε1−ε2 are larger than one, the
wave-vector is larger in magnetic media. In other words, the surface plasmon
polariton (SSP) wavelength is smaller. Because the electric field component Ex
is proportional to k2 and Ez is proportional to β, a stronger localized
near-field light can be produced. A shorter surface resonance wavelength should
lead to a smaller focused spot. A stronger electric-field component should
indicate that the incident infrared waves are already confined to a near-field
space over the magnetic-to-dielectric interface and therefore that light
absorption by the nanostructured magnetic film should be higher.
Tapered structures are commonly utilized for nanofocusing.3,13,143. D. K.
Gramotnev and S. I. Bozhevolnyi, Nat. Photonics 8, 14 (2014).
https://doi.org/10.1038/NPHOTON.2013.23213. D. Wei, Z. Xin, M. Chen, C. Hu, X.
Zhang, H. Wang, and C. Xie, AIP Adv. 9, 065103 (2019).
https://doi.org/10.1063/1.509346914. D. Wei, C. Hu, M. Chen, J. Shi, J. Luo, X.
Zhang, H. Wang, and C. Xie, Opt. Mater. Express 10, 105 (2020).
https://doi.org/10.1364/OME.382116 Surface waves excited on tapered structures
gradually concentrate the incident energy and localize the light field, thus
enhancing the amplitude along the propagation direction. In this paper, tapered
structures including nanotip and nanorhombus arrays are used to study the SPP
excited on a magnetic metasurface in order to achieve perfect absorption and
nanofocusing.
Similar planar nanotip arrays were defined on aluminum and Tb14Fe68Co18 film
surfaces. Scanning electron microscope (SEM) images and sample fabrication
processes are shown in Fig. 1. Typical nanotip metasurface morphologies on
aluminum and Tb14Fe68Co18 films, respectively, are illustrated in Figs. 1(a) and
1(c). The aluminum nanotip array exhibited a clear structural edge that
indicates high etch and transfer precision. However, the Tb14Fe68Co18 nanotip
film provided a relatively poor processing result. The nanostructured aluminum
film was fabricated via electron beam lithography (EBL, Vistec EBPG 5000plus ES)
and inductively coupled plasma (ICP, plasmonic APX300/E600) etching, as
illustrated in Fig. 1(b). The nanostructured Tb14Fe68Co18 film was fabricated
using a typical liftoff process, as illustrated in Fig. 1(d). The magnetic
medium utilized was a multilayer film system made from Si3N4
(60 nm)/Tb14Fe68Co18 (20 nm)/Si3N4 (5 nm)/AlTi (10 nm). The multilayer
Tb14Fe68Co18 film was deposited via magnetron sputtering (JS550 ∼ S/3). Because
sputtering requires heating and the photoresist does not usually survive high
temperatures, silica was used as a liftoff material. Since many reactants
remained on the nanostructured Tb14Fe68Co18 film during the liftoff process, the
processing efficiency was relatively poor.
FIG. 1. Planar nanotip arrays fabricated over both the Tb14Fe68Co18 film and an
aluminum film. (a) Scanning electron microscope (SEM) image of an aluminum
nanotip metasurface. (b) The fabrication process used to shape a planar nanotip
array on an aluminum film. (c) SEM image of a magnetic nanotip metasurface. (d)
The fabrication process used to shape a nanotip array on the Tb14Fe68Co18
magnetic metasurface. (e) Nanotip metasurface light reflectivities at infrared
wavelengths of 3 μm–15 μm.
   
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The light reflectivities of the fabricated nanotip metasurfaces were measured
via Fourier transform infrared spectroscopy (FT-IR, VERTEX 70) and the results
are shown in Fig. 1(e). All of the collected data were normalized using
silver-coated plano mirrors (Thorlabs PFSQ10-03-P01), which present high
infrared reflectance characteristics (>96% for 3 μm to 15 μm). The Tb14Fe68Co18
nanotip metasurface exhibits less light reflectivity than the aluminum nanotip
metasurface. Generally, the reflectivity of the aluminum nanotip metasurface is
between ∼30% and ∼40% in the 3 μm–15 μm wavelength region, but the reflectivity
of the Tb14Fe68Co18 nanotip metasurface is less than 30%. A lower reflectivity
indicates a higher light absorptivity. At an initial wavelength of 3 μm, the
reflectivities of both nanotip metasurfaces are similar. When the wavelength
increases, the reflectivity of the Tb14Fe68Co18 nanotip metasurface is lower
than that of the aluminum metasurface and the gap between the metasurfaces
increases gradually. At a wavelength of ∼15 μm, there is a maximum gap of more
than 10%. When the Tb14Fe68Co18 nanotip array is compared to a nanotip aluminum
film, obvious magnetic loss is noted. This indicates direct absorption of light
energy that is incident upon the Tb14Fe68Co18 nanotip array.
Stable near-field light distributions acquired using the aluminum and
Tb14Fe68Co18 nanotip metasurfaces were measured via scanning near-field optical
microscopy (SNOM, Neaspec GmbH Co.), as shown in Fig. 2. The incident directions
and polarization collocation of the incident lasers used to measure the
near-field optical characteristics are shown in Fig. 2(a). A spherical
coordinate system is used to describe the incident directions of the beams used
in SNOM testing. Both θ and φ are set to 45° and the incident beams are
p-polarized. The beam incidence is labeled using a round, red arrow and the
polarization is indicated using a square, red arrow. The sample is illuminated
using a far-infrared beam with a wavelength of 10 μm. A platinum probe is used
to detect the electric field signals from the near-field light wave. In magnetic
media, the SPP wavelength is shorter and the electric-field component Ez is
larger. As shown in Figs. 2(b) and 2(c), the maximum of the electric field is
approximately 6.3 μV over the aluminum nanotip array but approximately 48 μV
over the Tb14Fe68Co18 nanotip array. The near-field optical properties
characterize the surface charge distribution behavior at the interface. Since
the near-field light waves are already perfectly localized on the Tb14Fe68Co18
nanotip array surface, the surface electrons are highly localized into the
nanotips. In contrast, what little near-field light is observed over the
aluminum nanotip array is constantly interrupted. The shorter wavelength of the
SPPs excited on the Tb14Fe68Co18 nanotip array results in more intense focusing.
FIG. 2. Typical fabricated nanotip metasurface near-field light distributions.
(a) Direction and polarization co-location of incident lasers used to measure
near-field optical characteristics. (b) A stable surface light field localized
slightly into an aluminum nanotip array. (c) A distinct surface light field
localized heavily into a linear Tb14Fe68Co18 nanotip array.
   
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 * High resolution

A TbCo nanorhombus metasurface is used to evaluate relationships between optical
properties and nanostructural parameters. TbCo is ferromagnetic with two
anti-parallel sublattices. Its magnetization can be reversed using the ultrafast
thermal effect produced by femtosecond lasers.1515. W. Cheng, X. Li, H. Wang, X.
Cheng, and X. Miao, AIP Adv. 7, 056018 (2017). https://doi.org/10.1063/1.4975659
The typical characteristics of a nanorhombus array-shaped TbCo magnetic film
deposited on a silicon substrate are characterized by its periods in the x-(P)
and y-(Q) directions and the two major-diagonal lengths (A) and (B) of each
single nanorhombus, as shown in Fig. 3(a). A liftoff method is used to fabricate
a nanorhombus TbCo metasurface shown in Fig. 3(b). Because the magnetron
sputtering used to form the TbCo magnetic film is performed at 300 K,
polymethylmethacrylate is used directly as a peeling material.
FIG. 3. Schematic diagram of a TbCo metasurface. (a) A nanorhombus metasurface
shaped over a magnetic film pre-deposited on the silicon substrate. (b) Typical
fabrication processes. (c) Reflectivity spectra of the measured samples,
including the TbCo metasurface, magnetic film, and silicon wafer.
   
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 * High resolution

The light reflectivity behaviors of various materials including the TbCo
metasurface, magnetic film, and silicon wafer, are shown in Fig. 3(c). It can be
seen that the TbCo metasurface has a lower reflectivity. The TbCo magnetic film
and silicon wafer are highly reflective, but the reflectivity decreases
gradually as the wavelength increases. The reflectivity of the TbCo film is
almost 100% in the 3 μm–4 μm range but approximately 75% at 15 μm. The
reflectivity of the silicon wafer is smaller since it is ∼65% at 3 μm and
reaches ∼40% at 15 μm. In contrast, in the 3 μm–15 μm wavelength range, the
reflectivity of the TbCo metasurface is approximately 20% and varies little.
Here, the filling factor (FF) is defined as the ratio of the TbCo nanostructure
area to the total surface area of the silicon wafer. Typically, the total light
reflectivity of the TbCo metasurface RMM should equal the sum of the weighted
reflectivities of the magnetic film RMF and the silicon wafer RSW. That is,
RMM = RMF × FF + RSW × (1 − FF). However, the practical reflectivity is much
lower than that given by the above calculation. We believe that the relatively
strong light absorption observed must be a result of strong excitation of SPPs
over the TbCo metasurface. The TbCo nanorhombus metasurface ensures that a large
number of incident beams are already coupled and thus stored in the TbCo
nanorhombus array as a highly localized near-field light wave by inducing strong
electric and magnetic dipole oscillations in each nanorhombus of the TbCo
metasurface. This serves to enhance light absorption in the sample greatly.
Ohmic and magnetic losses may serve as additional factors that enhance light
absorption markedly. Since the TbCo nanorhombus array is periodic, its light
reflectivity is decreased further by effectively coupling adjacent nanorhombuses
in order to enhance the light absorption greatly.
The light reflection characteristics of TbCo metasurfaces with different
structural parameter configurations were obtained. Figures 4(a)–4(d) present
four similar TbCo nanorhombus arrays with different nanorhombus sizes. The
metasurfaces named array-a, -b, -c, and -d with the structural parameters A, B,
P, and Q are 1930 nm, 540 nm, 2090 nm, and 1439 nm; 1976 nm, 782 nm, 2108 nm,
and 1445 nm; 1999 nm, 990 nm, 2120 nm, and 1440 nm; and 2066 nm, 1238 nm,
2066 nm, and 1449 nm, respectively. Moreover, the FF parameters that correspond
to array-a, -b, -c, and -d are ∼17.3%, ∼25.3%, ∼32.4%, and 42.7%, respectively.
Figure 4(e) presents the TbCo metasurface reflectance spectra in the 3 μm–15 μm
wavelength range. As shown, all TbCo metasurfaces labeled using different colors
exhibit similar variance trends and relatively soft spectral reflectivities that
oscillate between ∼20.2% and ∼21.4%. No obvious peak is measured in the infrared
wavelength region. Thus, the infrared reflective behaviors of the TbCo
metasurfaces are based primarily on a collective, featured nanorhombus surface
resonance electromagnetic excitation response to incident infrared radiation.
These are arranged in an orderly, dense manner to shape a special metasurface
over the TbCo magnetic film system. The light reflectivity decreases gradually
as the FF increases. We can predict that the reflectivity decreases by 0.2% for
every 10% increase in the FF.
FIG. 4. Light reflection characteristics of TbCo metasurfaces with various
structural parameter configurations. SEM images of the fabricated nanorhombus
arrays with structural parameters A, B, P, and Q: (a) 1930 nm, 540 nm, 2090 nm,
and 1439 nm; (b) 1976 nm, 782 nm, 2108 nm, and 1445 nm; (c) 1999 nm, 990 nm,
2120 nm, and 1440 nm; and (d) 2066 nm, 1238 nm, 2066 nm, and 1449 nm. (e)
Reflection spectra of the TbCo nanorhombus arrays shown above.
   
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The near-field light distribution characteristics of the TbCo metasurfaces are
shown in Fig. 5. The SNOM test conditions are the same as those shown in Fig.
2(a). Each nanorhombus “edge” is marked by a black dotted outline as per each
SNOM light-field drawing. In general, the near-field light intensity is low
around the outer edge of each nanorhombus, as indicated by the overlapping blue
hollow nanorhombuses. During SNOM testing, two approaches to near-field
nanofocusing were used: in light energy nanofocusing, one gathers all near-field
light waves into each nanorhombus, while in light field nanofocusing, one forms
a small, sharp spot of focused light.
FIG. 5. Typical near-field light wave distributions over TbCo metasurfaces with
various structural parameter configurations. The detailed structural parameters
A, B, P, and Q are (a) 1930 nm, 540 nm, 2090 nm, and 1439 nm; (b) 1976 nm,
782 nm, 2108 nm, and 1445 nm; (c) 1999 nm, 990 nm, 2120 nm, and 1440 nm; and (d)
2066 nm, 1238 nm, 2066 nm, and 1449 nm, respectively. (e) The incident beam
allocation used in SNOM testing. (f) The relationship between the light spot
length and the short diagonal (A) of a single nanorhombus. (g) The relationship
between the light spot width and the aforementioned short diagonal. (h) The
relationship between the light-spot intensity and the aforementioned short
diagonal.
   
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 * High resolution

The light energy nanofocusing approach involves collecting as much light energy
as possible into each nanorhombus from outside, as indicated by the wide, dark
blue box in the inset in Fig. 5(d). The light-field nanofocusing approach
involves forming light spots that are as small and sharp as possible. The
average light-spot size in each graph is used as the typical light-spot size and
the maximum field strength is used as the light-spot intensity. As shown, the
average light-spot intensity and size are (∼1.44 μV, ∼420 × 1000 nm2),
(∼1.27 μV, ∼370 × 560 nm2), (∼1.49 μV, ∼400 × 820 nm2), and (∼1.66 μV,
∼760 × 1250 nm2) in Figs. 5(a)–5(d), respectively. Consequently, ideal
nanofocusing is presented in Fig. 5(b). Figures 5(f) and 5(g) show the
relationship between the average light spot size and the short diagonal length
of the nanorhombus. When the short diagonal length is greater than or equal to
0.78 μm, the near-field light is focused near the center of each nanorhombus.
The average long and short light-spot edge sizes enlarge as the short diagonal
length increases. Figure 5(h) shows the relationship between the average light
spot intensity and the length of the short diagonal of a single nanorhombus.
Variation in the nanostructural parameters can cause substantial changes in
near-field optical behavior. When the short diagonal length of a single
nanorhombus is greater than or equal to 0.78 μm, the light-spot intensity
increases with the short diagonal length. This characterizes the surface free
electron distribution of the magnetic film, leading to a highly localized or
compressed re-arrangement of the surface free electrons. The infrared
reflectivity can be modulated by defining the required surface layout and
rationally configuring the structural parameters of the resulting magnetic
metasurface.
In this study, a nanostructured magnetic metasurface was formed on a silicon
wafer to demonstrate ideal near-field light nanofocusing and infrared light
absorption in a wide wavelength range of 3 μm–15 μm for advanced solar cells.
The magnetic film surface charge distribution could be controlled by finely
adjusting the nanostructural parameters. The infrared reflectivity of the shaped
magnetic metasurface could then be further modulated. A theoretical analysis
showed that the surface plasmon polaritons excited on the magnetic-to-dielectric
interface had larger wave vectors and stronger electric field components than
those excited on the metal-to-dielectric interface. The fabricated Tb14Fe68Co18
nanotip array exhibited lower infrared reflectivities and more powerful
localized nanofocusing abilities than those shaped on common aluminum films. The
convergent light spot could be modulated effectively via careful configuration
of the TbCo nanorhombus arrays. This research also highlights some potential
applications such as super-high resolution image detection, low-cost
nanolithography, and ultra-high-density photoinduced magnetic recording.
The authors acknowledge the financial support from the National Natural Science
Foundation of China (Nos. 61432007, 61176052, and 61821003) and the China
Aerospace Science and Technology Innovation Fund (No. CASC2015). The authors
thank Xiaolei Wen from the University of Science and Technology of China for
SNOM testing.
The authors declare no conflicts of interest.
DATA AVAILABILITY

The data that support the findings of this study are available from the
corresponding authors upon reasonable request.

REFERENCES

 1.  1. E. Cubukcu, N. Yu, E. J. Smythe, L. Diehl, K. B. Crozier, and F.
     Capasso, IEEE J. Sel. Top. Quantum Electron. 14, 1448 (2008).
     https://doi.org/10.1109/JSTQE.2007.912747, Google ScholarCrossref
 2.  2. N. Liu, M. L. Tang, M. Hentschel, H. Giessen, and A. P. Alivisatos, Nat.
     Mater. 10, 631 (2011). https://doi.org/10.1038/nmat3029, Google
     ScholarCrossref
 3.  3. D. K. Gramotnev and S. I. Bozhevolnyi, Nat. Photonics 8, 14 (2014).
     https://doi.org/10.1038/NPHOTON.2013.232, Google ScholarCrossref
 4.  4. C. Wu, B. Neuner, G. Shvets, J. John, A. Milder, B. Zollars, and S.
     Savoy, Phys. Rev. B 84, 075102 (2011).
     https://doi.org/10.1103/PhysRevB.84.075102, Google ScholarCrossref
 5.  5. F. Yi, H. Zhu, J. C. Reed, and E. Cubukcu, Nano Lett. 13, 1638 (2013).
     https://doi.org/10.1021/nl400087b, Google ScholarCrossref
 6.  6. R. Bardhan, S. Lal, A. Joshi, and N. J. Halas, Acc. Chem. Res. 44, 936
     (2011). https://doi.org/10.1021/ar200023x, Google ScholarCrossref
 7.  7. N. Yu and F. Capasso, Nat. Mater. 13, 139 (2014).
     https://doi.org/10.1038/nmat3839, Google ScholarCrossref
 8.  8. D. Franklin, Y. Chen, A. Vazquez-Guardado, S. Modak, J. Boroumand, D.
     Xu, S.-T. Wu, and D. Chanda, Nat. Commun. 6, 7337 (2015).
     https://doi.org/10.1038/ncomms8337, Google ScholarCrossref
 9.  9. H. Cheng, S. Q. Chen, P. Yu, X. Y. Duan, B. Y. Xie, and J. G. Tian,
     Appl. Phys. Lett. 103, 203112 (2013). https://doi.org/10.1063/1.4831776,
     Google ScholarScitation, ISI
 10. 10. G. M. Akselrod, J. Huang, T. B. Hoang, P. T. Bowen, L. Su, D. R. Smith,
     and M. H. Mikkelsen, Adv. Mater. 27, 8028 (2015).
     https://doi.org/10.1002/adma.201503281, Google ScholarCrossref
 11. 11. P. D. Terekhov, K. V. Baryshnikova, Y. Greenberg, Y. H. Fu, A. B.
     Evlyukhin, A. S. Shalin, and A. Karabchevsky, Sci. Rep. 9, 3438 (2019).
     https://doi.org/10.1038/s41598-019-40226-0, Google ScholarCrossref
 12. 12. X. Zhang, H. Lou, Z. G. Zhang, Q. Wang, and S. N. Zhu, Sci. Rep. 7,
     41858 (2017). https://doi.org/10.1038/srep41858, Google ScholarCrossref
 13. 13. D. Wei, Z. Xin, M. Chen, C. Hu, X. Zhang, H. Wang, and C. Xie, AIP Adv.
     9, 065103 (2019). https://doi.org/10.1063/1.5093469, Google
     ScholarScitation, ISI
 14. 14. D. Wei, C. Hu, M. Chen, J. Shi, J. Luo, X. Zhang, H. Wang, and C. Xie,
     Opt. Mater. Express 10, 105 (2020). https://doi.org/10.1364/OME.382116,
     Google ScholarCrossref
 15. 15. W. Cheng, X. Li, H. Wang, X. Cheng, and X. Miao, AIP Adv. 7, 056018
     (2017). https://doi.org/10.1063/1.4975659, Google ScholarScitation, ISI

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    licensed under a Creative Commons Attribution (CC BY) license
    (http://creativecommons.org/licenses/by/4.0/).







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