• Journal of the Optical Society of Korea
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• 제18권6호
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• pp.793-798
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• 2014

To generate finite-power Airy beams, a novel holographic method is proposed. We record the interference pattern between an Airy beam (signal beam) and plane wave (reference beam) on a photopolymer, then decode the hologram by illuminating with the reference beam. The reconstructed beams still present the non-diffraction, acceleration, and self-healing features of optical Airy beams. In addition, angular multiplexing of two Airy beams with opposite acceleration directions is presented.

• Current Optics and Photonics
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• 제7권6호
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• pp.608-637
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• 2023

The initial motivation in colloid science and engineering was driven by the fact that colloids can serve as excellent models to study atomic and molecular behavior at the mesoscale or microscale. The thermal behaviors of actual atoms and molecules are similar to those of colloids at the mesoscale or microscale, with the primary distinction being the slower dynamics of the latter. While atoms and molecules are challenging to observe directly in situ, colloidal motions can be easily monitored in situ using simple and versatile optical microscopic imaging. This foundational approach in colloid research persisted until the 1980s, and began to be extensively implemented in optics and photonics research in the 1990s. This shift in research direction was brought by an interplay of several factors. In 1987, Yablonovitch and John modernized the concept of photonic crystals (initially conceptualized by Lord Rayleigh in 1887). Around this time, mesoscale dielectric colloids, which were predominantly in a suspended state, began to be self-assembled into three-dimensional (3D) crystals. For photonic crystals operating at optical frequencies (visible to near-infrared), mesoscale crystal units are needed. At that time, no manufacturing process could achieve this, except through colloidal self-assembly. This convergence of the thirst for advances in optics and photonics and the interest in the expanding field of colloids led to a significant shift in the research paradigm of colloids. Initially limited to polymers and ceramics, colloidal elements subsequently expanded to include semiconductors, metals, and DNA after the year 2000. As a result, the application of colloids extended beyond dielectric-based photonic crystals to encompass plasmonics, metamaterials, and metasurfaces, shaping the present field of colloidal optics and photonics. In this review we aim to introduce the research trajectory of colloidal optics and photonics over the past three decades; To elucidate the utility of colloids in photonic crystals, plasmonics, and metamaterials; And to present the challenges that must be overcome and potential research prospects for the future.

• 한국광학회:학술대회논문집
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• 한국광학회 2006년도 하계학술발표회 논문집
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• pp.2-2
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• 2006

• 광학과기술
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• 제11권3_4호
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• pp.38-40
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• 2007

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.76.2-76.2
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• 2015

I will present my research group's recent investigation on how the localized plasmon of a nanoparticle interacts with another plasmon, and with nearby molecules. First, I will demonstrate the use of scattering-type scanning near-field microscopy (s-SNOM) to directly visualize the capacitive / conductive coupling in dimeric nanoparticles and heterometallic nanorods. Second, I will talk about the use of gap-plasmons to locally induce photochemical reactions, and to follow chemical kinetics of individual organic molecules using the gap-plasmons. As a last topic, I will talk about the use of near-field coupling between a scanning probe and graphenes to visualize / identify the stacking domains (e. g., ABA versus ABC-type stacking in triple layer) hidden in multilayer graphenes.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.408-408
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• 2014

Graphene has received attention with its high electron mobility and visual transparency as a promising material for optoelectronic and photonic applications. Combination of graphene and conducting nanostructures i.e. plasmonic structures has recently been researched for enhancing light-matter interaction and overcoming diffraction limit of light. Here we show enhanced photodetection of incoherent visible light with graphene-mediated plasmonics. Gold nanoparticles fabricated by focused ion beam was used as an active element of photodetection and graphene was utilized as an interfacing material between nanostructures and electrodes. Hot electrons generated upon plasmon decay within nanoparticles pass over the potential barrier between nanostructure and graphene and give rise to a photocurrent with built-in electric field. We report 76.7% enhancement of photocurrent under resonant irradiation of fiber-coupled halogen lamp compared to the case without light illumination. We showed wavelength-dependent current response arisen from plasmonic nanostructure, providing a good agreement with theoretical calculation.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.75-75
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• 2015

Strong interactions between electromagnetic radiation and electrons at metallic interfaces or in metallic nanostructures lead to resonant oscillations called surface plasmon resonance with fascinating properties: light confinement in subwavelength dimensions and enhancement of optical near fields, just to name a few [1,2]. By utilizing the properties enabled by geometry dependent localization of surface plasmons, metal photonics or plasmonics offers a promise of enabling novel photonic components and systems for integrated photonics or sensing applications [3-5]. The versatility of the nanoplasmonic platform is described in this talk on three folds: our findings on an enhanced ultracompact photodetector based on nanoridge plasmonics for photonic integrated circuit applications [3], a colorimetric sensing of miRNA based on a nanoplasmonic core-satellite assembly for label-free and on-chip sensing applications [4], and a controlled fabrication of plasmonic nanostructures on a flexible substrate based on a transfer printing process for ultra-sensitive and noise free flexible bio-sensing applications [5]. For integrated photonics, nanoplasmonics offers interesting opportunities providing the material and dimensional compatibility with ultra-small silicon electronics and the integrative functionality using hybrid photonic and electronic nanostructures. For sensing applications, remarkable changes in scattering colors stemming from a plasmonic coupling effect of gold nanoplasmonic particles have been utilized to demonstrate a detection of microRNAs at the femtomolar level with selectivity. As top-down or bottom-up fabrication of such nanoscale structures is limited to more conventional substrates, we have approached the controlled fabrication of highly ordered nanostructures using a transfer printing of pre-functionalized nanodisks on flexible substrates for more enabling applications of nanoplasmonics.

• Journal of applied mathematics & informatics
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• 제31권1_2호
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• pp.111-118
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• 2013

External excitations are employed to investigate properties of optical media, with measurement data often analyzed via linear response theory. In this respect, external forcing is modeled here by well-known Poisson and negative-binomial distributions. Ensuing dynamics is examined with a special attention to the relative decay rates of damped harmonic oscillators to such external forcing, along with its relationship to other physical phenomena.

• Current Optics and Photonics
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• 제6권6호
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• pp.576-582
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• 2022

Plasmonic high-order harmonic generation (HHG) is used in nanoscale optical applications because it can help in realizing a compact coherent ultrashort pulse generator on the nanoscale, using plasmonic field enhancement. The plasmonic amplification of nanostructures induces nonlinear optical phenomena such as second-order harmonic generation, third-order harmonic generation, frequency mixing, and HHG. This amplification also causes damage to the structure itself. In this study, the plasmonic amplification according to the design of a metal-coated sapphire conical structure is theoretically calculated, and we analyze the effects of this optical amplification on HHG and damage to the sample.

• 한국전기전자재료학회논문지
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• 제25권7호
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• pp.516-520
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• 2012

In this paper, we have theoretically analyzed and designed a dielectric multi-layer sensor with a SPR (surface plasmon resonance) using analytical calculation and FDTD (finite difference time-domain) methods. The proposed structure is composed of periodic layer and thin metal film. It has many advantages. One of that is a high sensitivity of the SPR. Another is a high Q-factor of the characteristics in the PhC (photonic crystals) micro-cavity structure. The incident light has double resonance characteristics, because the filtered light by PhC structure, dielectric multi-layer, is met the thin metal film for SPR effect. We have also observed the change of resonance characteristics according to the variation of effective index on the metal film.