92
K. Huang
Fig. 4.7 a Sketch of dielectric chiral metasurfaces that use Nb 2 O 5 to manipulating the ultraviolet
light. b The simulated conversion efficiency of Nb 2 O 5 -base chiral metasurfaces at the interested
wavelength of 355 nm. Considering the limitation of fabrication issue, the width is set to be 70 nm.
The simulation is carried out by scanning the length and height of nanostructures with the help of
FDTD methods. c The broadband response of the optimized nanostructures with W = 70 nm, L =
150 nm and H = 430 nm. d–e The simulated electric and magnetic fields under the illumination of E x
and E y -polarization light. The inserts show the simplified sketches of magnetic dipoles. Reproduced
with the permission from 2019 WILEY-VCH Verlag GmbH [15]
which thus enable the same orientation of both the electric vectors at the bottom and
top ends of nanostructure (see Fig. 4.7d). It means that the x-component of CP light is
not changed after the electromagnetic interaction with nanostructures. However, for
E y component, the antiferromagnetic mode is induced with three AMPs, leading to
the odd circular currents that could reverse the electric vector of light at the terminal
of transmission, as observed in Fig. 4.7e. It indicates a phase delay of π, which is
desired for realizing high conversion efficiency. As a result, the transmitted light has
the orthogonal polarization to the incident light, which is highly deserved in highefficiency meta-devices [15]. Figure 4.8 sketches the details during the entire optical
process intermediated by antiferromagnetic modes during the realization of circular
polarization conversion into its cross-polarization.
Two coupling effects dominates the electromagnetic interaction between the oscillating nanomodes and the designed nanostructures [15]. Firstly, the number of the
reduced magnetic dipoles in the antiferromagnetic nanomode is determined by the
coupling between the volume modes and the dimension of nanostructures. Along the
long axis (i.e., x axis) of nanostructures, the volume of magnetic dipole moments is
K. Huang
Fig. 4.7 a Sketch of dielectric chiral metasurfaces that use Nb 2 O 5 to manipulating the ultraviolet
light. b The simulated conversion efficiency of Nb 2 O 5 -base chiral metasurfaces at the interested
wavelength of 355 nm. Considering the limitation of fabrication issue, the width is set to be 70 nm.
The simulation is carried out by scanning the length and height of nanostructures with the help of
FDTD methods. c The broadband response of the optimized nanostructures with W = 70 nm, L =
150 nm and H = 430 nm. d–e The simulated electric and magnetic fields under the illumination of E x
and E y -polarization light. The inserts show the simplified sketches of magnetic dipoles. Reproduced
with the permission from 2019 WILEY-VCH Verlag GmbH [15]
which thus enable the same orientation of both the electric vectors at the bottom and
top ends of nanostructure (see Fig. 4.7d). It means that the x-component of CP light is
not changed after the electromagnetic interaction with nanostructures. However, for
E y component, the antiferromagnetic mode is induced with three AMPs, leading to
the odd circular currents that could reverse the electric vector of light at the terminal
of transmission, as observed in Fig. 4.7e. It indicates a phase delay of π, which is
desired for realizing high conversion efficiency. As a result, the transmitted light has
the orthogonal polarization to the incident light, which is highly deserved in highefficiency meta-devices [15]. Figure 4.8 sketches the details during the entire optical
process intermediated by antiferromagnetic modes during the realization of circular
polarization conversion into its cross-polarization.
Two coupling effects dominates the electromagnetic interaction between the oscillating nanomodes and the designed nanostructures [15]. Firstly, the number of the
reduced magnetic dipoles in the antiferromagnetic nanomode is determined by the
coupling between the volume modes and the dimension of nanostructures. Along the
long axis (i.e., x axis) of nanostructures, the volume of magnetic dipole moments is