Special issue: Metamaterials and plasmonics in Asia, a tribute to Byoungho Lee
In memory of Prof. Byoungho Lee
Advances and applications on non-Hermitian topological photonics
Non-Hermitian photonics and topological photonics, as new research fields in optics, have attracted much attention in recent years, accompanying by a great deal of new physical concepts and novel effects emerging. The two fields are gradually crossed during …
Topological phases and non-Hermitian topology in photonic artificial microstructures
In the past few decades, the discovery of topological matter states has ushered in a new era in topological physics, providing a robust framework for strategically controlling the transport of particles or waves. Topological photonics, in particular, has …
Recent advanced applications of metasurfaces in multi-dimensions
Unlike traditional optical components, which rely on the gradual accumulation of light along the optical path over a distance much larger than the wavelength to form a wavefront, metasurfaces manipulate light field properties on the wavelength thickness by …
Recent advances in oblique plane microscopy
Oblique plane microscopy (OPM) directly captures object information in a plane tilted from the focal plane of the objective lens without the need for slow z-stack acquisition. This unconventional widefield imaging approach is made possible by using a remote …
A symmetry-protected exceptional ring in a photonic crystal with negative index media
Non-Hermitian topological band structures such as symmetry-protected exceptional rings (SPERs) can emerge for systems described by the generalized eigenvalue problem (GEVP) with Hermitian matrices. In this paper, we numerically analyze a photonic crystal with …
Highly angle-sensitive and efficient optical metasurfaces with broken mirror symmetry
Optical metasurfaces have great potential to overcome the functional limitations of conventional optical devices. In addition to polarization- or wavelength-multiplexed metasurfaces, angle-multiplexed metasurfaces can provide new degrees of freedom, enabling …
Multilayer all-polymer metasurface stacked on optical fiber via sequential micro-punching process
Metasurface technology is revolutionizing the field of optics and pursuing expanded functions via technical developments, such as the integration of multiple metasurfaces with optical fibers. Despite several attempts to realize metasurface-on-fiber platforms, …
Inverse design of high-NA metalens for maskless lithography
We demonstrate an axisymmetric inverse-designed metalens to improve the performance of zone-plate-array lithography (ZPAL), one of the maskless lithography approaches, that offer a new paradigm for nanoscale research and industry. First, we derive a …
Deterministic approach to design passive anomalous-diffraction metasurfaces with nearly 100% efficiency
Designing perfect anomalous reflectors is crucial for achieving many metasurface-based applications, but available design approaches for the cases of extremely large bending angles either require unrealistic gain–loss materials or rely on brute-force …
Metasurface spatial filters for multiple harmonic signals
Nonlinear frequency mixings have shown an alternative way to create new electromagnetic sources in frequency ranges that are difficult to access with conventional techniques. To simultaneously use the fundamental frequency pump beam and multiple harmonic …
Multiple symmetry protected BIC lines in two dimensional synthetic parameter space
Bound states in the continuum (BICs) have attracted significant interest in recent years due to their unique optical properties, such as infinite quality factor and wave localization. In order to improve the optical performance of BICs based devices, more …
Deep-learning-assisted reconfigurable metasurface antenna for real-time holographic beam steering
We propose a metasurface antenna capable of real-time holographic beam steering. An array of reconfigurable dipoles can generate on-demand far-field patterns of radiation through the specific encoding of meta-atomic states i.e., the configuration of each …
On-chip integration of metasurface-doublet for optical phased array with enhanced beam steering
Optical phased array (OPA), as a promising beam steering technology, however, usually suffers from a narrow field of view (FOV) that limits its performances in applications. A miniaturized compact strategy to enlarge the beam steering angle is quite desirable …
Multi-frequency amplitude-programmable metasurface for multi-channel electromagnetic controls
The digital and programmable metasurfaces, as opposed to conventional metasurfaces, offer a more sophisticated method of collaborating information and physics, showcasing several real-time controls to electromagnetic (EM) ways in succinct ways. In this work, …
Broadband absorber with dispersive metamaterials
A broadband absorber that utilizes a dispersive metamaterial and covers the entire microwave X-band (8–12 GHz) is proposed in the present study. An ideal absorber attached to the surface of a perfect electric conductor requires the permittivity of the …
Visible-mid infrared ultra-broadband and wide-angle metamaterial perfect absorber based on cermet films with nano-cone structure
Metamaterial absorbers over a broadband spectrum with high absorption, good angular tolerance, and easy configurations have essential importance for optical and optoelectronic devices. In this study, a hybrid metamaterial absorber comprising multilayered …
Vertical photon sorting by stacking silicon and germanium nanopillars for broadband absorbers
Perfect absorbers based on all-dielectric metasurfaces exhibit great potential in photodetection, photovoltaics, and imaging applications. This study proposes and demonstrates an all-dielectric broadband absorber comprising subwavelength-thick nanopillar Mie …
Directive emission from polymeric fluorophore with epsilon-near-zero squaraine molecular film
Enhanced directionality of photoluminescence emission has attracted attention due to its diverse application areas ranging from single-photon sources to fluorescence sensing and bio-imaging. Utilization of null phase advance in epsilon-near-zero (ENZ) medium …
Chiral-magic angle of nanoimprint meta-device
The magic angle of Twistronics has attracted a lot of attention because of its peculiar electrical characteristics. Moiré patterns formed by the superlattice of a twisted bilayer change overall physical properties. Circular dichroism can also be manipulated …
Fluorescence engineering in metamaterial-assisted super-resolution localization microscope
Single-molecule localization microscopies have gained much attention for their efficient realization of a sub-diffraction-limit imaging with the resolution down to the 10-nm range. In contrast to conventional localization microscopes, which rely on particular …
Nano-shaping of chiral photons
Localized surface plasmon polaritons can confine the optical field to a single-nanometer-scale area, strongly enhancing the interaction between photons and molecules. Theoretically, the ultimate enhancement might be achieved by reducing the “photon size” …
Design principles for electrically driven Luttinger liquid-fed plasmonic nanoantennas
Electrons injected into one-dimensional (1D) metals are efficiently converted into infrared plasmons because the unique property of the Luttinger liquid, a strongly correlated electronic matter in one-dimensional (1D) metals, prohibits excitations of other …
Ultrafast strong-field terahertz nonlinear nanometasurfaces
Strong-field terahertz (THz)–matter interaction permits the investigation of nonequilibrium behaviors in the nonperturbative zone. However, the unavailability of a high-field free-space THz source with high repetition rates, excellent beam quality, and high …
Reconfigurable anomalous reflectors with stretchable elastic substrates at 140 GHz band
We propose reconfigurable anomalous reflectors with stretchable elastic substrates. The proposed reflector dynamically controls the reflection direction by mechanically stretching the substrate to induce a physical change of the unit cell period. Owing to the …
Polarization-independent isotropic metasurface with high refractive index, low reflectance, and high transmittance in the 0.3-THz band
Metasurfaces substituted for naturally occurring materials make it possible to develop flat optics manipulating terahertz waves. However, the control of unprecedented material properties with metasurfaces frequently produces anisotropic material properties …
Terahertz nanofuse by a single nanowire-combined nanoantenna
We propose a terahertz nanofuse through irreversible modulations in transmitted terahertz using nanowires-combined nanoantenna structures. Semiconductor and metal nanowires show irreversible reconfiguration in their geometry at an incident field of 20 kV/cm. …
Electrically tunable THz graphene metasurface wave retarders
Anisotropic materials with chirality or birefringence can be used to manipulate the polarization states of electromagnetic waves. However, the comparatively low anisotropy of natural materials hinders the miniaturization of optical components and devices at …
Ultra-thin grating coupler for guided exciton-polaritons in WS_2 multilayers
An ultra-thin transition metal dichalcogenide (TMDC) layer can support guided exciton-polariton modes due to the strong coupling between excitons and photons. Herein, we report the guided mode resonance in an ultra-thin TMDC grating structure. Owing to the …
Reflection of two-dimensional surface polaritons by metallic nano-plates on atomically thin crystals
Owning to their unusual optical properties, such as electrical tunability and strong spatial confinement, two-dimensional surface polaritons (2DSPs) hold great promise for deep sub-wavelength manipulation of light in a reduced low-dimensional space. Control …
A deep neural network for general scattering matrix
The scattering matrix is the mathematical representation of the scattering characteristics of any scatterer. Nevertheless, except for scatterers with high symmetry like spheres or cylinders, the scattering matrix does not have any analytical forms and thus …
Engineering isospectrality in multidimensional photonic systems
Selective manipulation of energy levels plays an essential role in realizing multichannel wave devices. One of the representative examples is to utilize the concept of quasi-isospectrality: a family of wave systems with an almost identical spectrum except for …
Heterogeneously integrated light emitting diodes and photodetectors in the metal-insulator-metal waveguide platform
We demonstrate heterogeneous integration of active semiconductor materials into the conventional passive metal-insulator-metal (MIM) waveguides to provide compact on-chip light generation and detection capabilities for chip-scale active nanophotonic …
DNA origami-designed 3D phononic crystals
Moulding the flow of phononic waves in three-dimensional (3D) space plays a critical role in controlling the sound and thermal properties of matter. To this end, 3D phononic crystals (PnCs) have been considered the gold standard because their complete …
All-dielectric carpet cloaks with three-dimensional anisotropy control
In this article, we propose all-dielectric carpet cloaks composed of jungle gym shaped dielectric unit cells and present a design strategy for three-dimensional (3-D) anisotropy control based on the transformation optics. The carpet cloaks are 3-D printable …