A5032432325- Plasmonic and Surface Plasmon Research
- Thermal Radiation and Cooling Technologies
- Strong Light-Matter Interactions
- Metamaterials and Metasurfaces Applications
- Photonic and Optical Devices
- Mechanical and Optical Resonators
- Orbital Angular Momentum in Optics
- Photorefractive and Nonlinear Optics
- Photonic Crystals and Applications
- Advanced Antenna and Metasurface Technologies
- Nonlinear Optical Materials Studies
- Optical Wireless Communication Technologies
- Optical Network Technologies
- Silicon Nanostructures and Photoluminescence
- Topological Materials and Phenomena
- Gold and Silver Nanoparticles Synthesis and Applications
- Advanced Fiber Laser Technologies
Korea Advanced Institute of Science and Technology
2021-2025
University of Southern Denmark
2019
Abstract The ability to control and manipulate the polarization state of light is crucial importance in many modern optical applications ranging from quantum technologies biomedical sciences. Here, an ultrathin quarter‐wave plate (QWP) with a gap‐surface plasmon metasurface designed, fabricated, experimentally demonstrated, allowing for broadband efficient conversion between circular linear polarizations ≈85% average reflectance across 200 nm wide bandwidth near‐infrared range (750–950 nm)....
An acoustic plasmonic mode in a graphene-dielectric-metal heterostructure has recently been spotlighted as superior platform for strong light-matter interaction. It originates from the coupling of graphene plasmon with its mirror image and exhibits largest field confinement limit nm-thick dielectric. Although detected far-field regime, optical near-fields this are yet to be observed characterized. Direct probing fields reflected by edges via near-field scattering microscope reveals...
Near-field mapping has been widely used to study hyperbolic phonon-polaritons in van der Waals crystals. However, an accurate measurement of the polaritonic loss remains challenging because inherent complexity near-field signal and substrate-mediated loss. Here we demonstrate that large-area monocrystalline gold flakes, atomically flat low-loss substrate for image polaritons, provide a platform precise complex propagation constant polaritons As topical example, measure hexagonal boron...
Active metasurfaces have been proposed as one attractive means of achieving high-resolution spatiotemporal control optical wavefronts, having applications such LIDAR and dynamic holography. However, full, phase has elusive in metasurfaces. In this paper, we unveil an electrically tunable metasurface design strategy that operates near the avoided crossing two resonances, a spectrally narrow, over-coupled resonance other with high frequency tunability. This displays unprecedented upper limit...
Abstract Controlling the wavefront of light, especially on a subwavelength scale, is pivotal in modern optics. Metasurfaces present unique platform for realizing flat lenses, called metalenses, with thicknesses order wavelength. Despite substantial effort, however, suppressing chromatic aberrations over large operational bandwidths metalenses still remains challenge. Here, we develop systematic design method enabling simultaneous, polarization-insensitive control phase and group delay light...
Abstract Topological insulators generally have dielectric bulk and conductive surface states. Consequently, some of these materials are shown to support polaritonic modes at visible THz frequencies. At the same time, optical properties topological in mid‐infrared (mid‐IR) remain poorly investigated. Here, near‐field imaging is employed probe mid‐IR response from exfoliated flakes bismuth (Bi)/selenide (Se)/telluride (Te)/antimony (Sb) crystals with varying stoichiometry – Bi 2 Se 3 , Te Se,...
Polaritonic crystals – periodic structures where the hybrid light–matter waves called polaritons can form Bloch states promise a deeply subdiffractional nanolight manipulation and enhanced light-matter interaction. In particular, in van der Waals materials boast extreme field confinement long lifetimes allowing for exploitation of wave phenomena at nanoscale. However, conventionally patterned nanostructures, are prone to severe scattering loss sharp material edges, making it challenging...
Abstract Orthorhombic molybdenum trioxide (α‐MoO 3 ), a newly discovered polaritonic van der Waals crystal, is attracting significant attention due to its strongly anisotropic mid‐infrared phonon‐polaritons. At the same time, coupling of polariton with mirror image in an adjacent metal gives rise significantly more confined mode. Here, monocrystalline gold flakes—an atomically flat low‐loss substrate for polaritons—are employed measure full complex‐valued propagation constant hyperbolic...
Scattering-type scanning near-field optical microscope (s-SNOM) has become an essential tool to study polaritons---quasiparticles of light coupled collective charge oscillations---via direct probing their near field with a spatial resolution far beyond the diffraction limit. However, extraction polariton's complex propagation constant from images requires subtle considerations that have not received necessary attention so far. In this study, we discuss important yet overlooked aspects...
Gap-surface plasmon metasurface-based quarter-wave plates have been used by Fei Ding, Yuanqing Yang and co-workers (article number 1801414) to generate vector vortex beams possessing spatially-varied distributions of the polarization carrying specified orbital angular momentums. The developed approach allows compact, cost-effective, high-performance converters be realized, paving way for ultimate miniaturization optical devices with arbitrary control light fields.
Scattering-type scanning near-field optical microscope (s-SNOM) has become an essential tool to study polaritons - quasiparticles of light coupled collective charge oscillations via direct probing their near field with a spatial resolution far beyond the diffraction limit. However, extraction polariton complex propagation constant from images requires subtle considerations that have not received necessary attention so far. In this study, we discuss important yet overlooked aspects analysis....
Polaritonic crystals - periodic structures where the hybrid light-matter waves called polaritons can form Bloch states promise a deeply subdiffractional nanolight manipulation and enhanced interaction. In particular, in van der Waals materials boast extreme field confinement long lifetimes allowing for exploitation of wave phenomena at nanoscale. However, conventionally patterned nanostructures, are prone to severe scattering loss sharp material edges, making it challenging create functional...
Monocrystalline gold flakes serve as an atomically-flat low-loss substrate for the highly confined mid-infrared "image polaritons" stemming from hybridization of polaritons with their mirror image in metal. By leveraging physical properties flakes, strongly anisotropic phonon are rigorously studied a biaxial van der Waals crystal α-MoO3 (see article number 2201492 by Min Seok Jang and co-workers). Notably, provide approximately twice stronger field confinement yet longer lifetime compared to...
Topological insulators generally have dielectric bulk and conductive surface states. Consequently, some of these materials been shown to support polaritonic modes at visible THz frequencies. At the same time, optical properties topological in mid-infrared (IR) remain poorly investigated. We employ near-field imaging probe mid-IR response from exfoliated flakes bismuth (Bi) / selenide (Se) telluride (Te) antimony (Sb) crystals with varying stoichiometry - Bi2Se3, Bi2Te2Se,...