A5024029362- Metamaterials and Metasurfaces Applications
- Plasmonic and Surface Plasmon Research
- Terahertz technology and applications
- Photonic and Optical Devices
- Advanced Antenna and Metasurface Technologies
- Photonic Crystals and Applications
- Perovskite Materials and Applications
- Strong Light-Matter Interactions
- Antenna Design and Analysis
- Mechanical and Optical Resonators
- Quantum optics and atomic interactions
- Cold Atom Physics and Bose-Einstein Condensates
- Advanced Photonic Communication Systems
- Physics of Superconductivity and Magnetism
- Microwave Engineering and Waveguides
- Topological Materials and Phenomena
- Solid-state spectroscopy and crystallography
- Spectroscopy and Laser Applications
- Microwave and Dielectric Measurement Techniques
- Millimeter-Wave Propagation and Modeling
- Advanced Frequency and Time Standards
- Thermal Radiation and Cooling Technologies
- Liquid Crystal Research Advancements
- Orbital Angular Momentum in Optics
- Random lasers and scattering media
Nanyang Technological University
2015-2025
Indian Institute of Science Bangalore
2023-2024
Rice University
2022-2023
National University of Singapore
2015-2017
Shanghai Jiao Tong University
2017
Centre for Quantum Technologies
2015
Raman Research Institute
2010-2014
A broad range of dynamic metasurfaces has been developed for manipulating the intensity, phase and wavefront electromagnetic radiation from microwaves to optical frequencies. However, most these operate in single-input-output state. Here, we experimentally demonstrate a reconfigurable MEMS Fano resonant metasurface possessing multiple-input-output (MIO) states that performs logic operations with two independently controlled electrical inputs an readout at terahertz The far-field behaviour...
Localized electromagnetic excitation in the form of toroidal dipoles has recently been observed metamaterial systems. The origin dipole lies currents flowing on surface a torus. Thus, exotic excitations play an important role determining optical properties system. Toroidal also contribute towards enabling high quality factor subwavelength resonances systems which could be excellent platform for probing light matter interaction. Here, we demonstrate sensing with resonance two-dimensional...
Independent control of near-field-coupled bright and dark resonators for active modulation frequency tuning electromagnetically induced transparency analogs in the terahertz spectral region is experimentally demonstrated. An out-of-plane reconfigurable microcantilever element resonator control. The proposed microelectromechanical systems (MEMS) metamaterial miniaturized, electrically controlled, can achieve up to an order magnitude change THz group-delay bandwidth product.
An operation range of the figure merit (FoM) that reflects trade-off between Q factor and resonance intensity Fano is provided. The structural asymmetry parameter α = (l1 − l2)/(l1 + l2) × 100% in resonator determines FoM has an optimized band for ranging from 4% to 8% terahertz resonant metasurfaces. As a service our authors readers, this journal provides supporting information supplied by authors. Such materials are peer reviewed may be re-organized online delivery, but not copy-edited or...
Fano resonances offer exciting features in enhancing the non-linearity and sensing capabilities metamaterial systems. An active photoswitching of a terahertz metadevice at low optical pump powers is demonstrated, which signifies extreme sensitivity high-quality-factor resonant electric field to external light illumination.
Bismuth double perovskite Cs 2 AgBiBr 6 strong electron–acoustic phonon interactions derail its photovoltaic aspirations.
The recent meteoric rise in the field of photovoltaics with discovery highly efficient solar-cell devices is inspired by solution-processed organic-inorganic lead halide perovskites that exhibit unprecedented light-to-electricity conversion efficiencies. stunning performance attributed to their strong photoresponsive properties are thoroughly utilized designing excellent perovskite solar cells, light-emitting diodes, infrared lasers, and ultrafast photodetectors. However, optoelectronic...
Abstract In recent years, the stunning performance of transition metal dichalcogenides (TMDCs) has been utilized in area field effect transistors, integrated circuits, photodetectors, light generation and harvesting, valleytronics, van der Waals (vdW) heterostructures. However, optoelectronic application TMDCs realizing efficient, ultrafast metaphotonic devices terahertz part electromagnetic spectrum remained unexplored. The most studied member TMDC family, i.e., MoS 2 , shows an carrier...
Incorporating semiconductors as active media into metamaterials offers opportunities for a wide range of dynamically switchable/tunable, technologically relevant optical functionalities enabled by strong, resonant light-matter interactions within the semiconductor. Here, germanium-thin-film-based flexible metaphotonic device ultrafast switching terahertz radiation is experimentally demonstrated. A transmission modulation depth 90% achieved, with an full recovery time 17 ps. An observed...
Electromagnetically induced transparency (EIT) arises from coupling between the bright and dark mode resonances that typically involve subwavelength structures with broken symmetry, which results in an extremely sharp band. Here, we demonstrate a tunable broadband EIT effect symmetry preserved metamaterial structure at terahertz frequencies. Alongside, also envisage photo-active hybrid metal-semiconductor metamaterial, where window can be dynamically switched by shining near-infrared light...
The quantum well in 2D perovskite provides an additional channel for photoexcited electrons to relax back at ultrafast time scale.
Fano resonances in metasurfaces are important due to their low loss subradiant behavior that allows excitation of high‐quality ( Q ) factor extending from the microwave optical regime. High‐ have recently enabled applications areas sensing, modulation, filtering, and efficient cavities for lasing spasers. Highly conducting metals most commonly used materials fabricating metasurfaces, especially at low‐frequency terahertz region where DC, Drude, perfect electric conductivity show similar...
Lattice modes are intrinsic to the periodic structures and their occurrence can be easily tuned controlled by changing lattice constant of structural array. Previous studies have revealed excitation sharp absorption resonances due mode coupling with plasmonic resonances. Here, we report first experimental observation a induced transparency (LIT) order (FOLM) resonance metamaterial resonator at terahertz frequencies. The observed is result destructive interference between bright FOLM mediated...
Solution-processed lead iodide (PbI2 ) governs the charge transport characteristics in hybrid metal halide perovskites. Besides being a precursor enhancing performance of perovskite solar cells, PbI2 alone offers remarkable optical and ultrasensitive photoresponsive properties that remain largely unexplored. Here, photophysics ultrafast carrier dynamics solution processed thin film is probed experimentally. A integrated metamaterial photonic device with switchable picosecond time response at...
We experimentally study the effect of near field coupling on transmission light in terahertz metasurfaces. Our results show that tailoring between resonators modulates amplitude resulting electromagnetically induced transmission, probed under different types asymmetries coupled system. Observed change is attributed to amount destructive interference vicinity strong coupling. employ a two-particle model theoretically influence bright and quasi-dark modes properties system we find an excellent...
Abstract Advances in plasmonic metamaterials have been rapidly evolving with innovations aimed at developing metadevices for real‐world applications. In reality, energy losses systems are prevalent and it is of paramount importance to come up solutions that could overcome the limitations impede further advancements toward miniaturization optoelectronic metadevices. High‐ Q Fano resonance as a scattering phenomenon can be easily triggered by introducing asymmetry into systems, thus offers...
Abstract The mechanism of Cooper pair formation and its underlying physics has long occupied the investigation into high temperature (high‐ T c ) cuprate superconductors. One ways to unravel this is observe ultrafast response present in charge carrier dynamics a photoexcited specimen. This results an interesting approach exploit dissipation‐less dynamic features superconductors be utilized for designing high‐performance active subwavelength photonic devices with extremely low‐loss operation....
We experimentally demonstrate the integration of a microfluidic trap array on top metamaterial resonators for size selective trapping and remote sensing microparticles. A split-ring resonator (SRR) design supports strongly confined electric field in capacitive split gap at fundamental inductive-capacitive resonance mode. The tightly SRR forms hot-spot that has become an enabling platform applications. Here, we extend concept to “trapping sensing” by fabricating trapezoidal shaped structures...
Abstract The Dirac semimetal cadmium arsenide (Cd 3 As 2 ), a 3D electronic analog of graphene, has sparked renewed research interests for its novel topological phases and excellent optoelectronic properties. gapless nature band facilitates strong optical nonlinearity supports plasmons that are particular interest to realize high‐performance photonic devices at terahertz (1 THz = 4.1 meV) frequencies, where the performance most dynamic materials limited by tradeoff between power‐efficiency...
Abstract Metamaterials exhibiting exotic optical properties have played a significant role over the years in guiding concept of invisibility cloaking from realm being fiction to reality. However, due difficulties fabricating 3D devices and lack plasmonic materials at terahertz (THz) frequencies, experimental realization phenomenon THz spectrum is challenging. In this work, new mechanism for based on resonant scattering cancellation technique 2D nonconcentric composite metamaterial device,...
We experimentally report a structurally reconfigurable metamaterial for active switching of near-field coupling in conductively coupled, orthogonally twisted split ring resonators (SRRs) operating the terahertz spectral region. Out-of-plane microcantilevers integrated into dark SRR geometry are used to provide frequency tuning resonance. The geometrical parameters individual SRRs designed have identical inductive-capacitive resonant frequency. This allows excitation classical analogue...
Superconducting metamaterials at terahertz frequencies has provided a platform for designing switchable plasmonic metamaterial devices. However, since metals are excellent conductors, the superior role of superconductors in low‐loss, high quality factor remains unclear. In this work, low asymmetry Fano resonant split‐ring‐resonator is considered which regime extremely radiative loss identified where temperature yttrium barium copper oxide superconductor meta‐atom supports sharp resonance...
We report experimental results of the active switching electromagnetically induced transparency (EIT) analogue by controlling dark mode excitation pathways in a microelectromechanical system based tri-atomic metamolecule, operating terahertz spectral region. The metamolecule consists two bright cut wire resonators (CWRs) on either side split ring (SRRs). Each CWRs can independently excite inductive-capacitive resonance SRRs through inductive coupling, and this allows for dual excitation. are...
Abstract Extreme terahertz (THz) science and technologies, the next disruptive frontier in nonlinear optics, provide multifaceted capabilities for exploring strong light‐matter interactions a variety of physical systems. However, current techniques involve need an extremely high‐field free space THz source that is difficult to generate has limited investigations rather weak linear regime interactions. Therefore, new approaches are being sought tight confinement waves can induce effects....