Article
Chemistry, Multidisciplinary
Mohammad Ali Eslamisaray, Parker R. Wray, Yeonjoo Lee, Gunnar M. Nelson, Ognjen Ilic, Harry A. Atwater, Uwe R. Kortshagen
Summary: We have developed a bottom-up nonthermal plasma process to produce highly monodisperse optically Mie-resonant crystalline silicon nano particles. The particle size can be controlled between 60 and 214 nm by adjusting the gas residence time in the reactor. By dispersing the nanoparticles in water, we observed colloidal solutions of a particle-based metafluid, exhibiting strong magnetic and electric dipole resonances at visible wavelengths. The spectral overlap of the electric and magnetic resonances leads to directional Kerker scattering. The excellent agreement between extinction measurements and Mie theory confirms the narrow size, shape, and composition distributions enabled by our fabrication process. Moreover, this gas-phase process allows the production of Mie-resonant nanoparticles of dielectric materials other than silicon and their direct deposition onto desired substrates.
Article
Optics
Myunghwan Kim, Sangin Kim, Soeun Kim
Summary: A new type of mid-infrared ultra-compact optical modulator composed of a graphene metasurface is proposed in this study. Unlike previous schemes, this modulator utilizes the topological characteristic of the isofrequency contour in the hyperbolic metasurface to modulate transmission, providing a modulation depth of 10.7 dB with a length of 750 nm, which is approximately 1/30 of an operating wavelength.
Article
Chemistry, Physical
Esmaeil Rahimi, Reuven Gordon
Summary: The study applies Bethe's theory to analyze the transmission of a subwavelength aperture in a metal film, treating it as a combination of a magnetic dipole and electric dipole for linear and nonlinear optics. The research shows that at angled incidence, the Lorentz force dominates the second harmonic generation, and matches well with the angular dependence of the magnetic and electric dipoles.
Article
Materials Science, Multidisciplinary
Akira Matsumori, Hiroshi Sugimoto, Minoru Fujii
Summary: This article proposes a silicon nanosphere with an access hole to the magnetic hotspot and develops corresponding fabrication process and analysis method. Through numerical simulations and experimental measurements, it is found that the magnetic field intensity is enhanced by 100-fold at the nanohole.
ADVANCED OPTICAL MATERIALS
(2022)
Article
Chemistry, Physical
Jie Zheng, Xianchao Liu, Mingyang Tian, Yarong Su, Ling Li
Summary: In this study, wafer-scale hybrid metal-dielectric gratings (HMDGs) consisting of aluminum and silicon (Al-Si) have been successfully fabricated as UV-SERS substrates to reduce ohmic dissipation and elevate the detection performance. Well-defined HMDG substrates exhibit tunable hybrid resonant modes in the UV and the visible regions. The proposed HMDG nanostructures have a great advantage in detecting important biomolecules as UV-SERS substrates, achieving a higher detection performance compared to conventional aluminum (Al) plasmonic nanostructures.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Nanoscience & Nanotechnology
Vimarsh Awasthi, Pariksha Malik, Richa Goel, Pankaj Srivastava, Satish Kumar Dubey
Summary: We have developed a sensitive and large-area SERS-active substrate by modifying a thin gold film on the unpolished side of a silicon wafer. This substrate allows for easy and rapid detection of analytes with high reproducibility, repeatability, and uniformity. The optimized substrate demonstrates a high degree of stability and can detect trace concentrations of TNT and DNT with low limits of detection. This work also highlights the advantages of using the rear side of a one-side-polished silicon substrate as a SERS-active chip.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Optics
Iryna Khodasevych, Patrick Rufangura, Francesca Iacopi
Summary: In this research, a closed-form expression for the polarizability of nanoparticles composed of nanolayers is derived, and the effects of different core materials and conductive shells on the absorption and scattering efficiency of nanoparticles are investigated. The results show that significant enhancement of absorption and scattering efficiency in the mid-infrared range can be achieved by combining graphene and polar dielectrics, assisted by coupling via a low permittivity spacer.
Article
Physics, Multidisciplinary
Olalla Castro-Alvaredo, Cecilia De Fazio, Benjamin Doyon, Aleksandra A. Ziolkowska
Summary: In this paper, the authors investigate the dynamical signatures of unstable excitations and their effects on the non-equilibrium properties of quantum field theory. Through the analysis of hot matter release and decay, the formation of tails and decay of nonlinear waves of unstable particles are observed, as well as the persistence of a stable population of unstable particles for long times. These signatures of unstable particles are expected to have a high degree of universality.
Article
Nanoscience & Nanotechnology
Hiroshi Sugimoto, Minoru Fujii
Summary: A composite system consisting of Si nanosphere decorated with Eu3+ complexes is developed to efficiently couple the magnetic dipole emission of Eu3+ to the magnetic Mie modes of the nanosphere. By tuning the magnetic quadrupole Mie resonance, the branching ratio between the magnetic and electric dipole transitions can be enhanced up to 7x. The magnetic Purcell enhancement is also demonstrated in an ensemble of Si nanospheres with size distribution.
Article
Mathematics
Manuel B. Branco, Isabel Colaco, Ignacio Ojeda
Summary: The research focuses on analyzing electromagnetic wave scattering by an impenetrable spherical object immersed in a lossless environment using a time-harmonic magnetic dipole. By formulating the scattering problem through expansions of magnetic and electric fields based on the wave number of the medium, the study simplifies Maxwell's equations to a set of interrelated elliptic partial differential equations. The presented analytical technique, based on spherical harmonic modes, provides compact three-dimensional solutions for scattered components and demonstrates efficiency by simplifying known results to a complete isotropic case.
Article
Mathematics
Eleni Stefanidou, Panayiotis Vafeas, Foteini Kariotou
Summary: The current research focuses on an analytical method for electromagnetic wave scattering by an impenetrable spherical object in a lossless environment. By expanding the magnetic and electric fields in terms of wave number of the medium, the study provides compact three-dimensional solutions for the scattered components. The approach neglects higher-order terms and demonstrates efficiency through example results.
Review
Nanoscience & Nanotechnology
V. S. Vendamani, S. V. S. Nageswara Rao, Anand P. Pathak, Venugopal Rao Soma
Summary: This review provides a comprehensive overview of recent developments in nanosensors composed of plasmonic nanoparticles and silicon nanostructures for trace-level molecular detection. It discusses methodologies for preparing various SiNSs and their potential applications in molecular sensing, especially based on SERS phenomenon. Additionally, demonstrations and categorizations are provided for a clear understanding, along with a roadmap for achieving superior sensing materials in the future.
ACS APPLIED NANO MATERIALS
(2022)
Article
Biochemistry & Molecular Biology
Saltanat B. Ikramova, Zhandos N. Utegulov, Kadyrjan K. Dikhanbayev, Abduzhappar E. Gaipov, Renata R. Nemkayeva, Valery G. Yakunin, Vladimir P. Savinov, Victor Yu Timoshenko
Summary: This study explored the use of silicon nanowires (SiNWs) combined with gold nanoparticles (Au NPs) for surface-enhanced Raman scattering (SERS) of probe molecules. The research found that the filling factor of SiNW arrays controlled the SERS efficiency, with the highest enhancement observed for samples with a porosity of 55%. The results demonstrate the electromagnetic enhancement of SERS through localized surface plasmon resonances in Au-NPs on SiNW surfaces, accompanied by light scattering in the SiNW arrays.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Review
Optics
Alexander Dorodnyy, Jasmin Smajic, Juerg Leuthold
Summary: Mie scattering is used to manipulate electromagnetic fields for various applications such as strong resonant enhancement, perfect absorption of radiation, and polarization/wavelength selectivity. Recent applications include light spectrum control, detection, non-linear effects enhancement, and emission. It is also demonstrated that a periodic arrangement of Mie scatterers can lead to a significant absorption enhancement in weakly absorbing layers.
LASER & PHOTONICS REVIEWS
(2023)
Article
Astronomy & Astrophysics
Sudip Mandal, Lakshmi Pradeep Chitta, Hardi Peter, Sami K. Solanki, Regina Aznar Cuadrado, Luca Teriaca, Udo Schuehle, David Berghmans, Frederic Auchere
Summary: This study presents an observational study of the plasma dynamics at the base of a solar coronal jet, revealing multiple plasma ejection events and complex morphological changes, including transitions between the standard and blowout type eruption.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Nanoscience & Nanotechnology
Nayeon Kim, Sungjun In, Dukhyung Lee, Jiyeah Rhie, Jeeyoon Jeong, Dai-Sik Kim, Namkyoo Park
Article
Multidisciplinary Sciences
Zahra Khajemiri, Dukhyung Lee, Seyedeh Mehri Hamidi, Dai-Sik Kim
SCIENTIFIC REPORTS
(2019)
Article
Chemistry, Multidisciplinary
Dasom Kim, Hyeong Seok Yun, Bamadev Das, Jiyeah Rhie, Parinda Vasa, Young-Il Kim, Sung-Hoon Choa, Namkyoo Park, Dukhyung Lee, Young-Mi Bahk, Dai-Sik Kim
Summary: Manipulating the topology of metamaterials on flexible substrates by mechanically closing/opening embedded nanotrenches can lead to abrupt switching of metamaterial functionalities such as resonance, chirality, and polarization selectivity. The closable nanotrenches in broadband spectrum metamaterials exhibit robust 99.9% extinction performance, enduring over a thousand bending cycles. This work provides a wafer-scale platform for active quantum plasmonics and photonic application of subnanometer phenomena.
Article
Optics
Hyeong Seok Yun, Dukhyung Lee, Dai-Sik Kim
Summary: By fabricating zero-thickness slot antennas with gradient metals near nanogaps to confine electromagnetic waves in tiny volumes, the efficiency of light-matter interaction is increased. This fabrication technique provides a simple yet versatile tool for maximum field enhancement and molecular sensing.
Article
Chemistry, Multidisciplinary
Dukhyung Lee, Dohee Lee, Hyeong Seok Yun, Dai-Sik Kim
Summary: Nanogap slits on a flexible substrate can be used to adjust cavity width by bending the substrate, affecting optical properties with angstrom-scale width control potential. The low displacement ratio comparable to a mechanically controllable break junction highlights the great potential of nanogap slit structures on a flexible substrate, particularly in quantum plasmonics.
Article
Nanoscience & Nanotechnology
Jiyeah Rhie, Sung Ju Hong, Dukhyung Lee, Dohee Lee, Hyeong Seok Yun, Young-Mi Bahk, Dai-Sik Kim
Summary: The study introduces a chip-scaled reversible terahertz resonator that can achieve tunable THz spectroscopy through mechanical bending, explained by theoretical simulation. Analysis of the resonator's electrical characteristics and optical properties were conducted, demonstrating molecular sensing capabilities. The detection limits for molecules within the gap region were determined to be 80.5 pg for lactose and 64.4 pg for caffeine, showing promise for stable and functional THz sensing applications.
ACS APPLIED NANO MATERIALS
(2021)
Article
Optics
Hyosim Yang, Dai-Sik Kim, Hyeong Seok Yun, Sunghwan Kim, Dukhyung Lee
Summary: In this study, a non-etching patterning method for vanadium dioxide (VO2) is demonstrated using photolithography and thermal oxidation. The resulting VO2 slit array metasurfaces show constant transparency in the terahertz range, regardless of the phase transition of the VO2 lines. In addition, the optical path difference between the slits and the VO2 lines can be controlled in the near-infrared range, allowing for selective switching of diffraction.
LASER & PHOTONICS REVIEWS
(2022)
Article
Optics
Sunghwan Kim, Dasom Kim, Youjin Lee, Geon Lee, Jeeyoon Jeong, Dukhyung Lee, Dai-Sik Kim
Summary: This paper presents a novel approach for achieving a broadband terahertz (THz) polarizer using a metallic slit array. The results demonstrate high transmittance and good extinction ratio over the entire THz spectrum. Theoretical calculations indicate the potential for achieving even wider bandwidths and higher cutoff frequencies by adjusting the slit periodicity.
Article
Optics
S. Jagan Mohan Rao, Dai-Sik Kim, Seon Namgung, Dukhyung Lee
Summary: Absorbers for long-wavelength infrared (LWIR) with a reduced geometry and fitted to a gold cross antenna were numerically studied in this research. The reduced geometry, compared to the square membrane geometry commonly used in traditional microbolometers, results in smaller thermal capacities of the vanadium dioxide (VO2) and silicon nitride (Si3N4) layers. However, the near-field focusing by the cross antenna enhances LWIR absorption. Calculations demonstrate that the temperature change per incident energy increases as the arm width decreases, and the reduced absorber outperforms the square geometry for all incident angles and polarizations. Therefore, the antenna-based reduced absorber investigated here could offer an alternative geometry for high-performance microbolometers.
Article
Nanoscience & Nanotechnology
Sunghwan Kim, Bamadev Das, Kang Hyeon Ji, Mahsa Haddadi Moghaddam, Cheng Chen, Jongjin Cha, Seon Namgung, Dukhyung Lee, Dai-Sik Kim
Summary: By introducing Cu clusters between planarized Au thin films sequentially deposited on a PET substrate, cracks can be formed along the photolithographically pre-determined lines with extremely high yield and repeatability. These clusters act as nanometer-sized spacers preventing the formation of contiguous metallic bond, enabling prepatterned-cracking. The wafer-scale prepatterned crack technology with macroscopic length and Angstrom-scale controllability is anticipated to have various applications in optoelectronics, quantum photonics, and photocatalysis.
Article
Chemistry, Analytical
Daehwan Park, Dukhyung Lee, Mahsa Haddadi Moghaddam, Dai-Sik Kim
Summary: This study investigates the formation of trenches under nanogap structures. The dependence of trench depth on strain and periodicity is derived, revealing that the trench deepens and diverges with increasing maximum tensile strain. Longer periods result in larger depths.
Article
Chemistry, Multidisciplinary
Hwanhee Kim, Mahsa Haddadi Moghaddam, Zhihao Wang, Sunghwan Kim, Dukhyung Lee, Hyosim Yang, Myongsoo Jee, Daehwan Park, Dai-Sik Kim
Summary: A flexible zerogap metallic structure that can heal metal cracks on a flexible substrate has been discovered. The size of the zerogap can be continuously adjusted by applying compressive strains on the flexible substrate. It was also found that nano-trenches are periodically generated on the polymer substrate below the zerogap, and the transmission properties of the material are related to the inverse of the radius of the curvature of the substrate.
Article
Multidisciplinary Sciences
Dukhyung Lee, Dasom Kim, Dai-Sik Kim, Hyeong-Ryeol Park, Changhee Sohn, Seon Namgung, Kunook Chung, Young Chul Jun, Dong Kyun Kim, Hyuck Choo, Young-Geun Roh
Summary: This report investigates the efficient electromagnetic heating of thermistor materials through plasmonic nanogap structures, focusing on the potential of nanorod dimer antennas filled with VO2 for long-wavelength infrared detection. Simulation results demonstrate the high heating ability of the nanogap, leading to a temperature rise several times higher than expected, making the dimer structures promising for high sensitivity bolometers.
SCIENTIFIC REPORTS
(2021)
Proceedings Paper
Engineering, Electrical & Electronic
Jiyeah Rhie, Young-Mi Bahk, Sung Ju Hong, Dukhyung Lee, Dai-Sik Kim
2020 45TH INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER, AND TERAHERTZ WAVES (IRMMW-THZ)
(2020)