Our Latest Research Outputs

Publications

저널, 컨퍼런스, 특허 등 μNOEL의 연구 결과를 한눈에 볼 수 있습니다.

2025

Journal

#114A wavelength-scale silk protein color filter array for ultra-high-resolution 80k DPI displays

Tae-Yun Lee, Jaegang Jo, Jihyun Lee, Kwanyhun Nam, Heonsu Jeon, Sunghwan Kim

Advanced Optical Materials

A sub-micrometer MIM color filter array is demonstrated using silk protein as an e-beam–tunable resist, enabling high-resolution, high-Q structural colors without complex nanofabrication. This approach achieves 80k-DPI images and offers new possibilities for ultrathin displays and color-based security.

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Journal

#113Colloidal-quantum-dot nanolaser oscillating at a bound-state-in-the-continuum with planar surface topography for a high Q-factor

Tae-Yun Lee, Hansol Lee, Heonsu Jeon

Nanophotonics

Demonstrates a colloidal quantum dot nanolaser that maintains the structural symmetry required for high-Q bound-state-in-the-continuum operation by planarizing the CQD film with a compliant squeegee. The resulting Si3N4 photonic-crystal backbone supports BIC lasing with ~10.5 kW/cm^2 threshold, far lower than prior CQD nanolasers, highlighting a scalable path to high-Q solution-processed lasers.

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Journal

#1121,550-nm photonic crystal surface-emitting laser diode fabricated by single deep air-hole etch

Myeongeun Kim, Ye-Seong Song, Lakjong Jeong, Tae-Yun Lee, Hyo Seok Choi, In Kim, Myungjae Lee, Heonsu Jeon

Nanophotonics

Introduces a simplified fabrication route for 1,550 nm photonic crystal surface-emitting laser diodes using a single deep air-hole etch that reaches the waveguide layer. Devices lase in a single mode at ~0.8 kA/cm^2 threshold current density, matching or exceeding previous PCSEL performance while dramatically reducing processing complexity and improving yield.

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2024

Journal

#111Recording and revealing 2.5d nanopatterned hidden information on silk protein bioresists

Tae-Yun Lee, Juwan Choi, Soohoun Lee, Heonsu Jeon, Sunghwan Kim

Small

Demonstrates low-energy electron-beam nanopatterning of silk protein bioresists by inducing controlled molecular degradation and selective cross-linking to record hidden 2.5D patterns. The cross-linked amorphous silk stores secure information and can be combined with fluorescent nanophotonic structures for enhanced visualization, pointing to applications in biomedical and security devices.

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Journal

#110Highly efficient and reliable organic light-emitting diodes enabled by a multifunctional hazy substrate for extreme environments

Yongmin Jeon, Tae-Yun Lee, Minwoo Nam, Hyeongyun Lee, Hyeunwoo Kim, Sun-Woo Lee, Seung Jin Oh, Seungyeop Choi, Jun-Yeong Yang, Sunghoon Jung, Seunghun Lee, Eun-Yeon Byeon, Taek-Soo Kim, Heonsu Jeon, Jeong Hyun Kwon

Advanced Functional Materials

This work presents multifunctional hazy substrates built on ion-beam-treated PET with high optical haze and waterproofing, laminated with distributed Bragg reflector and functional polymer layers to provide gas barriers and UV filtering. Flexible OLEDs using the substrate show 73% higher efficiency, strong environmental stability, low water vapor transmission, and mechanical robustness, enabling reliable operation in extreme conditions.

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2023

Journal

#109Resonant cavity phosphor

Tae-Yun Lee, Yeonsang Park, Heonsu Jeon

Nature Communications

Colloidal quantum dot phosphors embedded in a tailored resonant cavity absorb ~87% of excitation photons and boost fluorescence ~29x across a ~13 nm linewidth, yielding red/green pixels whose gamut exceeds sRGB when paired with a broad blue source. The planar RC design offers a practical structurally engineered phosphor platform for real devices.

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Journal

#108Imaging phonon eigenstates and elucidating the energy storage characteristics of a honeycomb-lattice phononic crystal cavity

P.H. Otsuka, R. Chinbe, M. Tomoda, O. Matsuda, Y. Tanaka, D.M. Profunser, S. Kim, H. Jeon, I.A. Veres, A.A. Maznev, O.B. Wright

Photoacoustics

Extends gigahertz time-domain imaging to map phonon eigenstates inside and outside a honeycomb-lattice phononic crystal cavity by probing the two-dimensional acoustic field of a silicon slab. The measurements reveal confined hexapole-like modes and quantify spatial acoustic energy storage, while simulations using toneburst excitation show the principal in-gap mode Q factor is limited by ultrasonic attenuation.

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2022

Journal

#107Engineering silk protein to modulate polymorphic transitions for green lithography resists

Soon-Chun Chung, Joon-Song Park, Rakesh Kumar Jha, Jieun Kim, Jinha Kim, Muyoung Kim, Juwan Choi, Hongdeok Kim, Da-Hye Park, Narendar Gogurla, Tae-Yun Lee, Heonsu Jeon, Ji-Yong Park, Joonmyung Choi, Ginam Kim, Sunghwan Kim

ACS Applied Materials & Interfaces

Artificial silk protein chemistry modulates β-sheet↔α-helix transitions to design water-based, green lithography resists; planar color filters with low angle-dependence demonstrate scalable silk resist manufacturing.

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Journal

#106Structurally engineered colloidal quantum dot phosphor using TiO2 photonic crystal backbone

Hansol Lee, Tae-Yun Lee, Yeonsang Park, Kyung-Sang Cho, Young-Geun Rho, Hyuck Choo, Heonsu Jeon

Light: Science & Applications

This study enhances two-dimensional square-lattice photonic crystal phosphors by using a high-index TiO2 backbone and removing excess colloidal quantum dots to planarize the surface. The structural engineering delivers simulated absorption enhancement of about 59x and experimental emission improvement of roughly 7x, producing efficient, polarization-immune phosphors.

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Journal

#105Photonic crystal L3 cavity laser fabricated using maskless digital photolithography

Minsu Kang, Heesoo Jin, Heonsu Jeon

Nanophotonics

This paper demonstrates fabrication of photonic crystal L3 cavity lasers using maskless digital photolithography, a cost-effective technique requiring no photomask. The approach enables submicron photonic crystal patterns with controlled air-hole shapes, offering a practical lithographic route for compact, economical photonic devices.

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2020

Journal

#104Submicrometer-scale pattern generation via maskless digital photolithography

Minsu Kang, Changhyun Han, Heonsu Jeon

Optica

This work demonstrates submicrometer-scale digital photolithography using a DMD system paired with a 200x objective to reach approximately 100 nm features. Techniques such as pattern tilting and grayscale exposure improve fidelity, and photonic crystal band-edge lasers with various lattices serve as test structures to validate the platform.

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Journal

#103Lasing at multidimensional topological states in a two-dimensional photonic crystal structure

Changhyun Han, Minsu Kang, Heonsu Jeon

ACS Photonics

This work demonstrates lasing at multidimensional topological states?two-dimensional bulk, one-dimensional edge, and zero-dimensional corner modes?in a hierarchical two-dimensional topological photonic crystal composed of tetramer air-hole clusters in an InGaAsP multiple-quantum-well epilayer. Optical pumping excites lasing at all nine hierarchical states, showcasing robust, multifunctional topological modes for integrated nanophotonic devices.

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2019

Journal

#102Enhanced upconversion luminescence by two-dimensional photonic crystal structure

Chenchen Mao, Kyungtaek Min, Kyuyoung Bae, Suehyun Cho, Tian Xu, Heonsu Jeon, Wonjung Park

ACS Photonics

This work demonstrates strong enhancement of upconversion luminescence by embedding silica-coated upconversion nanoparticles into a two-dimensional Si₃N₄ photonic crystal thin-film structure. The photonic crystal enhances the local electric field near the near-infrared excitation wavelength, amplifying the nonlinear upconversion process. Luminescence increases by roughly 130× in the green channel and 350× in the red channel, offering a low-loss dielectric platform for upconversion applications without plasmonic quenching.

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Journal

#1012D square lattice photonic crystal phosphor films for efficient and excitation polarization insensitive color conversion

Tae-Yun Lee, Jongho Lee, Yeonsang Park, Kyungtaek Min, Heonsu Jeon

Advanced Optical Materials

This work introduces two-dimensional square-lattice photonic crystal phosphor films that remove the polarization dependence observed in earlier one-dimensional designs. The four-fold rotational symmetry eliminates excitation polarization sensitivity, and increasing the high-index backbone thickness generates dual excitation resonances for TE and TM modes, doubling phosphor efficiency. Using colloidal quantum dots as the phosphor, the device achieves roughly fourfold excitation-insensitive fluorescence enhancement at the dual resonance wavelengths, consistent with simulations.

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Journal

#100Taming of random lasers

Myungjae Lee, Segolene Callard, Christian Seassal, Heonsu Jeon

Nature Photonics

This study investigates how to control the inherently unpredictable behavior of random lasers in a compositionally disordered photonic crystal platform. Photonic band-tail states, interpreted as photonic Anderson localizations, govern the lasing behavior, and regulating their statistical formation provides a pathway to stabilize random lasers.

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Journal

#99Lasing at topological edge states in a photonic crystal L3 nanocavity dimer array

Changhyun Han, Myungjae Lee, Segolene Callard, Christian Seassal, Heonsu Jeon

Light: Science & Applications

This work demonstrates lasing at topological edge states in a photonic crystal L3 nanocavity dimer array designed via the Su?Schrieffer?Heeger model. InP-based multi-quantum-well cavity arrays exhibit edge-localized lasing that remains robust against fabrication disorder, confirmed through emission spectra, near-field imaging, and simulations, marking a key step toward topologically protected photonic crystal lasers.

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2018

Journal

#98Tunable colloidal quantum dot distributed feedback lasers integrated on a continuously chirped surface grating

Hyunho Jung, Changhyun Han, Hanbit Kim, Kyung-Sang Cho, Young-Geun Roh, Yeonsang Park, Heonsu Jeon

Nanoscale

This study demonstrates a tunable colloidal quantum dot distributed feedback laser integrated with a continuously chirped surface grating fabricated via a modified Lloyd-type interferometric lithography setup using a concave mirror. A dense red-emitting CdSe/CdS/ZnS quantum dot film is wet-transferred onto the chirped grating, yielding single-mode lasing tunable from 613.4 to 623.2 nm across a 5.6 mm chirped region with ~400 uJ/cm^2 threshold, providing a compact wavelength-tunable CQD laser platform.

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Journal

#97Electrical modulation of a photonic crystal band-edge laser with a graphene monolayer

Hanbit Kim, Myungjae Lee, Hyunhak Jeong, Min-Soo Hwang, Ha-Reem Kim, Seondo Park, Yun Daniel Park, Takhee Lee, Hong-Gyu Park, Heonsu Jeon

Nanoscale

This study demonstrates electrical modulation of a photonic crystal band-edge laser by integrating a monolayer graphene sheet atop an InGaAsP multiple-quantum-well photonic crystal. Gate tuning of the graphene Fermi level adjusts its optical absorption, enabling low-voltage (|Vg| <= 1 V) modulation of microwatt-scale laser output. A dielectric spacer balances gain and absorption, and ion-gel encapsulation provides efficient gating, highlighting the feasibility of electrically tuned photonic crystal lasers.

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Journal

#96High-contrast infrared absorption spectroscopy via mass-produced coaxial zero-mode resonators with sub-10 nm gaps

Daehan Yoo, Daniel A. Mohr, Ferran Vidal-Codina, Aurelian John-Herpin, Min Sik Jo, Sunghwan Kim, Joseph Matson, Joshua D. Caldwell, Heonsu Jeon, Ngoc-Cuong Nguyen, Luis Martin-Moreno, Jaime Peraire, Hatice Altug, Sang-Hyun Oh

Nano Letters

This paper demonstrates wafer-scale fabrication of resonant coaxial nanoapertures with sub-10 nm gaps for surface-enhanced infrared absorption spectroscopy. The coaxial zero-mode resonators are produced via photolithography, atomic layer deposition, and glancing-angle ion milling, enabling up to 34% of incident IR light to funnel into nanogaps at their Fabry?Perot resonance. Incorporating silk protein into the gaps yields strong SEIRA signals with enhancement factors of 10^4?10^5, offering a mass-producible platform for ultrasensitive vibrational spectroscopy.

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Journal

#94Anderson localizations and photonic band-tail states observed in compositionally disordered platform

Myungjae Lee, Jeongkug Lee, Sunghwan Kim, Segolene Callard, Heonsu Jeon

Science Advances

This study provides the first experimental confirmation of photonic band-tail states and the complete Anderson localization transition in a compositionally disordered photonic crystal alloy platform. Eigenstate-resolved measurements reveal clear band-tail states and localization behavior, validating long-standing theoretical predictions and enabling future efforts to harness disorder-induced photon confinement.

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2017

Journal

#95Wet-transfer of freestanding dense colloidal quantum dot films and their photonic device application

Changhyun Han, Hyunho Jung, Jongho Lee, Myungjae Lee, Yeonsang Park, Kyung-Sang Cho, Heonsu Jeon

Advanced Materials Technologies

This paper reports a wet-transfer method for producing freestanding, densely packed colloidal quantum dot films by using poly(vinyl alcohol) as a sacrificial layer and poly(methyl methacrylate) as a temporary support. Large-area films about 1 cm x 1 cm can be transferred onto varied substrates with minimal mechanical or optical damage, and stacked to form CQD heterostructures. A CdSe-based CQD distributed feedback laser is demonstrated by placing a thick CQD film onto a grating substrate, achieving single-mode lasing with a high spontaneous emission factor.

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Communication

#93Photonic crystal phosphors integrated on a blue LED chip for efficient white light generation

Jongho Lee, Kyungtaek Min, Yeonsang Park, Kyung-Sang Cho, Heonsu Jeon

Advanced Materials

This work integrates photonic crystal phosphors onto a blue LED chip to realize a compact, efficient white-light source. Red- or green-emitting colloidal quantum dots are coated on Si₃N₄ thin-film photonic crystal gratings to form engineered phosphor plates whose band-edge modes match the blue LED excitation. Stacked photonic crystal phosphors produce 8% higher total emission intensity while requiring 33% less CQD material than reference phosphors, demonstrating enhanced color conversion.

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Journal

#92Efficient on-chip integration of a colloidal quantum dot photonic crystal band-edge laser with a coplanar waveguide

Hyunho Jung, Myungjae Lee, Changhyun Han, Yeonsang Park, Kyung-Sang Cho, Heonsu Jeon

Optics Express

This study demonstrates an on-chip integration technique for photonic integrated circuits in which a high-index coplanar waveguide layer doubles as the structural backbone. A two-dimensional photonic crystal band-edge laser is patterned into the backbone, colloidal quantum dots act as the gain medium, and optical pumping yields coherent single-mode lasing that couples efficiently into adjacent waveguides, enabling low-loss coupling between active and passive photonic components.

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Journal

#91Single-mode distributed feedback laser operation in solution-processed halide perovskite alloy system

Hyungrae Cha, Seunghwan Bae, Hyunho Jung, Min Jae Ko, Heonsu Jeon

Advanced Optical Materials

This work reports single-mode distributed feedback lasing from solution-processed halide perovskite alloy films CH(NH2)2Pb(I1−xBrx)3 with smooth morphology and tunable photonic bandgaps. By varying the halide composition, emission wavelengths shift from near-infrared to green, and quartz surface gratings enable stable single-mode lasing over a wide temperature range. Grating-period control dictates polarization, highlighting the potential of perovskite alloys for tunable optoelectronic laser devices.

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Journal

#90A colloidal quantum dot photonic crystal phosphor: nanostructural engineering of the phosphor for enhanced color conversion

Kyungtaek Min, Hyunho Jung, Yeonsang Park, Kyung-Sang Cho, Young-Geun Roh, Sung Woo Hwang, Heonsu Jeon

Nanoscale

This study introduces a nanostructurally engineered photonic crystal phosphor using colloidal quantum dots embedded in a one-dimensional photonic crystal thin-film structure. By matching the photonic band-edge mode with the excitation photon energy, absorption is significantly enhanced, yielding roughly four times higher fluorescence intensity than a bulk phosphor and demonstrating improved color conversion performance.

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Journal

#89Single-mode distributed feedback laser operation with no dependence on the morphology of the gain medium

Muhammad Umar, Kyungtaek Min, Heonsu Jeon, Sunghwan Kim

Annalen der Physik

This work presents a reusable photonic template enabling single-mode distributed feedback lasing independent of the gain-medium morphology. A one-dimensional quartz grating with 25 nm TiO2 disconnected-line structures spatially confines DFB modes regardless of optical thickness or liquid/film state of the gain medium. Experiments and simulations confirm stable single-mode lasing even with irregular biological gain materials.

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Journal

#88Origin and biomimicry of weak iridescence in black-billed magpie feathers

Changhyun Han, Hanbit Kim, Hyunho Jung, Sang-Im Lee, Piotr G. Jablonski, Heonsu Jeon

Optica

This study investigates the microstructural origin of the weak iridescence observed in black-billed magpie feathers. Cross-sectional analysis revealed vertically layered melanin-tube structures along the barbule cortex that generate the weak structural coloration, while lateral arrangement contributes little. Artificial polymer gratings patterned to mimic the barbules reproduced the iridescent behavior, confirming that cortex thickness predominates in determining coloration.

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Journal

#87Biocompatible, optically transparent, patterned, and flexible electrodes and radio-frequency antennas prepared from silk protein and silver nanowire networks

Kyungtaek Min, Muhammad Umar, Haekyo Seo, Jong Hyuk Yim, Dong Gun Kam, Heonsu Jeon, Soonil Lee, Sunghwan Kim

RSC Advances

This work demonstrates patterned silver nanowire networks embedded in silk fibroin films to build flexible, biocompatible, and optically transparent electrodes suitable for radio-frequency antennas. The AgNW-silk composite offers low sheet resistance (~15 Ω/sq), high transparency, and mechanical robustness, enabling its use in bioelectronic and soft-electronic applications.

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2016

Journal

#86Enhanced light outcoupling of polymer light-emitting diodes with a solution-processed, -flattening photonic-crystal underlayer

Donghyun Kim, Jaeheung Ha, Jongjang Park, Jun Hwang, Heonsu Jeon, Changhee Lee

Journal of Information Display

This study demonstrates enhanced light outcoupling in polymer light-emitting diodes by applying a solution-processed gallium-doped zinc oxide layer as both a planarizing electrode and a photonic-crystal underlayer. The corrugated PC surface is coated with GZO, which flattens the anode while preserving photonic-crystal effects. PLEDs using the PC-embedded GZO anode show higher efficiency and stronger areal emission, especially in device arrays.

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Research Article

#85Effective mobility enhancement of amorphous in-ga-zn-o thin-film transistors by holographically generated periodic conductor

Jaewook Jeong, Joonwoo Kim, Donghyun Kim, Heonsu Jeon, Soon Moon Jeong, Yongtaek Hong

AIP Advances

The study demonstrates a mobility enhancement method for fully transparent amorphous In-Ga-Zn-O thin-film transistors by embedding a holographically generated periodic nano-conductor in the back-channel region. The intrinsic field-effect mobility doubles compared to reference devices because the conductive nano-conductor pathway effectively shortens the channel length. The scalable approach combines holographic and conventional lithography without altering the IGZO channel composition.

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Communication

#84Physically transient distributed feedback laser using optically activated silk bio-ink

Hyunho Jung, Kyungtaek Min, Heonsu Jeon, Sunghwan Kim

Advanced Optical Materials

This study demonstrates a physically transient distributed feedback laser using optically activated silk bio-ink patterned on a one-dimensional surface grating. The silk layer can be removed with water and recoated to create fresh single-use lasers, enabling biodegradable, disposable photonic components. The device shows reliable lasing behavior and can detect toxic acid vapor, highlighting potential for eco-friendly chemosensing applications.

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Communication

#83Eco-friendly photolithography using water-developable pure silk fibroin

Joonhan Park, Sung-Gyu Lee, Benedetto Marelli, Myungjae Lee, Taehyung Kim, Hye-Keun Oh, Heonsu Jeon, Fiorenzo G. Omenetto, Sunghwan Kim

RSC Advances

This study demonstrates a fully eco-friendly photolithography technique using pure silk fibroin as a green, water-developable photoresist suitable for deep ultraviolet lithography. All steps—from resist coating to development—are entirely water-based without organic solvents. DUV exposure photo-denatures silk fibroin, reducing crystallinity and enabling pattern formation, providing a sustainable alternative to conventional photolithography materials.

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Journal

#82Two-dimensional photonic crystal bandedge laser with hybrid perovskite thin film for optical gain

Hyungrae Cha, Seunghwan Bae, Myungjae Lee, Heonsu Jeon

Applied Physics Letters

The study demonstrates a room-temperature, optically pumped single-mode laser incorporating a thin hybrid perovskite film as the gain medium. A 2D square-lattice photonic crystal backbone enables single-mode laser operation through photonic bandedge modes, while CH3NH3PbI3 perovskite provides the optical gain. Lasing from both Γ-point and M-point bandedge modes is observed, with similar thresholds around ~200 μJ/cm². Polarization-dependent measurements distinguish the isotropic Γ-point mode from the highly anisotropic M-point mode, confirming that lasing originates from the corresponding photonic crystal bandedge modes.

Paper

#81Colloidal quantum dot lasers built on a passive two-dimensional photonic crystal backbone

Hojun Chang, Kyungtaek Min, Myungjae Lee, Minsu Kang, Yeonsang Park, Kyung-Sang Cho, Young-Geun Roh, Sung Woo Hwang, Heonsu Jeon

Nanoscale

This work demonstrates room-temperature lasing in two-dimensional photonic crystal structures consisting of a passive Si3N4 backbone over-coated with CdSe/CdS/ZnS core-shell colloidal quantum dots (CQDs). Under optical pumping, devices lase in dual PC band-edge modes, with mode switching determined by the CQD overlayer thickness. The PC-CQD hybrid platform enables efficient coupling between active CQD gain media and passive photonic crystal components, suggesting potential for integrated on-chip photonic circuits.

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Journal

#80Period-chirped gratings fabricated by laser interference lithography with a concave lloyd’s mirror

Hanbit Kim, Hyunho Jung, Dong-Hyun Lee, Kyu Back Lee, Heonsu Jeon

Applied Optics

Describes concave Lloyd’s mirror laser interference lithography system that produces period-chirped gratings over wide areas with ΔΛ=92 nm across 17 mm.

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2015

Journal

#79A highly tunable and fully biocompatible silk nanoplasmonic optical sensor

Myungjae Lee, Heonsu Jeon, Sunghwan Kim

Nano Letters

Silk plasmonic absorber sensors using silk protein spacers and gold nanostructures achieve ~1200 nm/RIU sensitivity and strong spectral shifts via controllable swelling, enabling biocompatible real-time sensing.

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Journal

#78Surface passivation of photonic crystal band-edge laser by atomic layer deposition of sio?

Kyungtaek Min, Suehyun Cho, Yeonsang Park, Heonsu Jeon

Nanotechnology

Atomic-layer-deposited SiO2 passivates photonic-crystal band-edge lasers, reducing nonradiative recombination and stabilizing lasing characteristics.

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Journal

#77A fully biocompatible single-mode distributed feedback laser

Yunkyung Choi, Heonsu Jeon, Sunghwan Kim

Lab on a Chip

Reports a freestanding silk–riboflavin–silver DFB laser operating in a single mode at 495 nm, highlighting its potential for biomedical photonics.

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2014

Journal

#76Novel and simple route to fabricate fully biocompatible plasmonic mushroom arrays adhered on silk biopolymer

Joonhan Park, Yunkyung Choi, Myungjae Lee, Heonsu Jeon, Sunghwan Kim

Nanoscale

Demonstrates biocompatible plasmonic mushroom arrays on silk fibroin via laser interference lithography, leveraging strong Au–silk adhesion for scalable biosensing substrates.

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Journal

#75Enhanced fluorescence from cdse/zns quantum dot nanophosphors embedded in a one-dimensional photonic crystal backbone structure

Kyungtaek Min, Serok Choi, Yunkyung Choi, Heonsu Jeon

Nanoscale

CdSe/ZnS quantum dots embedded in a 1D photonic crystal polymer backbone show 1.36× fluorescence enhancement when the pump energy matches the photonic band edge.

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2013

Journal

#74Highly efficient, spatially coherent distributed feedback lasers from dense colloidal quantum dot films

C. Dang, J. Lee, K. Roh, H. Kim, S. Ahn, H. Jeon, C. Breen, J. S. Steckel, S. Coe-Sullivan, A. Nurmikko

Applied Physics Letters

Demonstrates dense colloidal quantum-dot DFB lasers with low thresholds under quasi-CW pumping, delivering >400 μW coherent output and 32% external quantum efficiency.

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Journal

#73Simultaneous observation of extended and localized modes in compositional disordered photonic crystals

Sunghwan Kim, Jeongkug Lee, Heonsu Jeon, Ségoléne Callard, Christian Seassal, Kyung-Deok Song, Hong-Gyu Park

Physical Review A

Mixed photonic crystals fabricated from wafer-bonded InAsP/InP slabs show disorder-induced localized photon modes alongside extended band-edge modes, as verified by emission spectroscopy and simulations.

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Journal

#72Selective lateral electrochemical etching of a gan-based superlattice layer for thin film device application

Dong-Uk Kim, Hojun Chang, Hyungrae Cha, Heonsu Jeon, Seong-Ran Jeon

Applied Physics Letters

Demonstrates lateral electrochemical etching of a 50-nm InGaN/AlGaN superlattice at ~0.8 μm/min using 0.3 M oxalic acid, enabling efficient epitaxial lift-off of 80 μm × 80 μm GaN platelets without degrading quantum-well emission.

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Journal

#71Nano stepping-stone laser

Sihan Kim, Sungmo Ahn, Kyungtaek Min, Sunghwan Kim, Heonsu Jeon, Philippe Regreny, Christian Seassal

Applied Physics Express

Introduces nano stepping-stone photonic crystal lasers comprising chains of discrete MQW nanorods bonded to fused silica, exhibiting single band-edge lasing with ~285 W/cm² thresholds and Q>10⁴.

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Journal

#70Improved emission efficiency of a-plane gan light emitting diodes with silica nano-spheres integrated

Y. G. Roh, K. S. Cho, Y. S. Park, H. Jeon

Applied Physics Letters

Integrating silica nanospheres on a-plane GaN LEDs boosts emission via scattering-assisted extraction without altering epitaxial structures.

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2012

Journal

#69Two-dimensional hexagonal lattice photonic crystal band-edge laser patterned by nanosphere lithography

Sungmo Ahn, Hanbit Kim, Heonsu Jeon, Jeong Rok Oh, Young Rag Do, Hyo Jin Kim

Applied Physics Express

Demonstrates 2D photonic crystal band-edge lasers using nanosphere lithography masks, producing circular air-hole arrays and lasing at the M1 band-edge near 1550 nm.

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Journal

#68Model calculations for enhanced fluorescence in photonic crystal phosphor

Kyungtaek Min, Yun-Kyoung Choi, Heonsu Jeon

Optics Express

Proposes 1D photonic crystal phosphor structures tuned to photonic band edges, showing calculated fluorescence enhancements of ~6.9 (monochromatic) and ~2.2 (broadband) excitation.

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2011

Journal

#67Effects of surface nano-topography on human osteoblast filopodia

Jin-Woo Lee, Kyu-Back Lee, Heon-Su Jeon, Hun-Kuk Park

Analytical Sciences

Human osteoblasts cultured on laser-interference nanopatterned surfaces reveal that low-density patterns guide filopodia extension while dense patterns hinder stable migration, producing shovel-like tips.

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Journal

#66Operation of photonic crystal laser in continuous-wave mode for 18 hours

Sihan Kim, Sunghwan Kim, Kyungwook Hwang, Heonsu Jeon, Hyo Jin Kim

Applied Physics Express

Demonstrates 18-hour continuous-wave operation of photonic crystal lasers using silicon/diamond/MgF₂ submounts and an MgF₂ top confinement layer, suggesting further improvements via better bonding.

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Journal

#65Electroluminescence from n–n isotype heterostructures of graded-band-gap znmgo:al and zno films on platinized si

Jong-Gul Yoon, Sung Woo Cho, W S Choi, Dae Yeol Kim, H Chang, C O Kim, J Lee, Heonsu Jeon, S-H Choi, T W Noh

Journal of Physics D: Applied Physics

Graded-band-gap ZnMgO:Al/ZnO n–n heterostructures on Pt/Ti/SiO₂/Si emit across visible–NIR ranges under 3–5 V, with nonlinear intensity and short-wavelength enhancement due to hot-electron-induced impact ionization.

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Journal

#64Free-standing gan-based photonic crystal band-edge laser

Dong-Uk Kim, Sunghwan Kim, Jeongkug Lee, Seong-Ran Jeon, Heonsu Jeon

IEEE Photonics Technology Letters

Honeycomb-lattice GaN photonic crystal band-edge lasers fabricated as free-standing membranes exhibit Γ₁ monopole-mode lasing at room temperature with ~15.5 mJ/cm² thresholds.

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Journal

#63Photonic crystal digital alloys and their band structure properties

Jeongkug Lee, Dong-Uk Kim, Heonsu Jeon

Optics Express

Microwave diamond-lattice photonic crystal digital alloys formed by alternating alumina and silica spheres emulate random alloy band gaps when the digital period is short, as shown by transmission measurements and band-structure calculations.

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Journal

#62Holography and plasma oxidation for uniform nanoscale two dimensional channel formation of vertical organic field-effect transistors with suppressed gate leakage current

Donghyun Kim, Jaewook Jeong, Hwairm Im, Sungmo Ahn, Heonsu Jeon, Changhee Lee, Yongtaek Hong

Organic Electronics

Demonstrates holographically patterned ~250 nm channels for vertical organic FETs, achieving on/off ratios ~10³ and further gate leakage suppression via plasma oxidation.

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Journal

#61Combined laser interference and photolithography patterning of a hybrid mask mold for nanoimprint lithography

Sungmo Ahn, Jinnil Choi, Eunhye Kim, Ki-Young Dong, Heonsu Jeon, Byeong-Kwon Ju, Kyu Back Lee

Journal of Nanoscience and Nanotechnology

Combines laser interference lithography with photolithography to fabricate hybrid mask molds for nanoimprint lithography, producing uniform 2D nanoscale patterns (~180 nm) transferable via PDMS molds.

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Journal

#60Milliwatt-level fiber-coupled laser power from photonic crystal band-edge laser

Sunghwan Kim, Sungmo Ahn, Jeongkuk Lee, Heonsu Jeon, Philippe Regreny, Christian Seassal, Emmanuel Augendre, Lea Di Cioccio

Optics Express

Large-area 2D photonic crystal band-edge lasers patterned via holography and bonded to fused silica achieve up to 2.6 mW fiber-coupled output with ~4% differential quantum efficiency.

Journal

#59Over 1 hour continuous-wave operation of photonic crystal lasers

Sunghwan Kim, Jeongkuk Lee, Heonsu Jeon

Optics Express

Demonstrates Γ-point photonic crystal lasers bonded to MgF₂–diamond submounts operating continuously for over one hour with fiber-coupled output ~200 μW, highlighting practical CW performance.

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2010

Journal

#58Absorbing one-dimensional planar photonic crystal for amorphous silicon solar cell

Ounsi El Daif, Emmanuel Drouard, Guillaume Gomard, Anne Kaminski, Alain Fave, Mustapha Lemiti, Sungmo Ahn, Sihan Kim, Pere Roca I Cabarrocas, Heonsu Jeon, Christian Seassal

Optics Express

Patterned 1D planar photonic crystals in amorphous silicon via laser holography plus RIE yield ~50% absorption enhancement between 0.38 and 0.75 μm, highlighting their suitability for photovoltaic structures.

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Journal

#57Fabrication of periodically polarity-inverted zno structures on (0001) al2o3

J.S. Park, T. Minegishi, S. Ahn, S.H. Park, S.K. Hong, H. Jeon, I.H. Im, J.H. Chang, T. Yao

Thin Solid Films

Plasma-assisted MBE with CrN template patterns yields 2D periodically polarity-inverted ZnO on (0001) Al2O3, confirmed by piezoresponse microscopy and He–Ne diffraction.

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Journal

#56Second harmonic generation in periodically polarity-inverted zinc oxide

Jinsub Park, Yoshiki Yamazaki, Masanobu Iwanaga, Sungmo Ahn, Heonsu Jeon, Takumi Fujiwara, Takafumi Yao

Optics Express

Reports SHG in periodically polarity-inverted ZnO heterostructures, demonstrating quasi-phase-matched conversion in nanometer-scale gratings formed on mixed-polarity surfaces.

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Journal

#55Band-edge lasers based on randomly mixed photonic crystals

Sunghwan Kim, Sungjoon Yoon, Hyojun Seok, Jeongkuk Lee, Heonsu Jeon

Optics Express

Random mixtures of two distinct InGaAsP photonic crystals yield new band structures with monotonic, strongly bowed band-edge shifts versus composition, matching FDTD simulations and virtual crystal approximation predictions.

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Journal

#54Single-defect photonic crystal cavity laser fabricated by a combination of laser holography and focused ion beam lithography

Sungmo Ahn, Sihan Kim, Heonsu Jeon

Applied Physics Letters

Hybrid laser holography and FIB lithography enable square-lattice InP photonic crystal cavity lasers with single air-hole defects, achieving Q≈2200 and ~0.25 mW thresholds comparable to e-beam fabricated devices.

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2009

Journal

#53Polarization-dependent gan surface grating reflector for short wavelength applications

Joonhee Lee, Sungmo Ahn, Hojun Chang, Jaehoon Kim, Yeonsang Park, Heonsu Jeon

Optics Express

Demonstrates holographically fabricated GaN surface grating reflectors optimized for TE-polarized blue wavelengths, achieving >90% reflectance with ~60 nm bandwidth in agreement with coupled-wave simulations.

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Journal

#52Algan membrane grating reflector

Jaehoon Kim, Dong-Uk Kim, Joonhee Lee, Heonsu Jeon, Yeonsang Park, Y.-S. Choi

Applied Physics Letters

Demonstrates holographically patterned AlGaN air-bridge membrane gratings (430 nm period, 0.55 fill factor) achieving ~90% TE reflectance at 532 nm, serving as alternatives to Bragg reflectors in GaN-based systems.

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Journal

#51Lateral arrays of vertical zno nanowalls on a periodically polarity-inverted zno template

Sang Hyun Lee, Tsutomu Minegishi, Jun-Seok Ha, Jin-sub Park, Hyo-Jong Lee, Hyun Jung Lee, Hitoshi Shiku, Tomokazu Matsue, Soon-Ku Hong, Heonsu Jeon

Nanotechnology

Reports aligned ZnO nanowall arrays selectively grown on Zn-polar regions of periodically polarity-inverted ZnO templates via carbothermal reduction, achieving high aspect ratios and confirmed single-crystalline quality.

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Journal

#50Fabrication of one-dimensional and two-dimensional periodically polarity inverted zno structures using patterned crn buffer layers

J. S. Park, T. Minegishi, S. H. Lee, I. H. Im, S. H. Park, T. Goto, M. W. Cho, T. Yao, S. K. Hong, J. W. Lee, J. Y. Lee, S. Ahn, H. Jeon, W. Lee, M. N. Jung, J. H. Chang

Journal of Vacuum Science & Technology B

Reports 1D and 2D periodically polarity-inverted ZnO structures grown on patterned CrN buffer layers, confirmed via piezoresponse force microscopy and showcasing high-quality cathodoluminescence and submicron holographically patterned ZnO templates.

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Journal

#49High-power and large-alignment-tolerance fiber coupling of honeycomb-lattice photonic crystal γ-point band-edge laser

Sunghwan Kim, Yeonsang Park, Kyungwook Hwang, Jeongkug Lee, Heonsu Jeon, Hyo Jin Kim

Journal of the Optical Society of America B

Honeycomb-lattice Γ-point photonic crystal lasers with butt-end fiber coupling provide >30 μW output and high alignment tolerance, with vertical oscillation influenced by angle-cleaved fiber tips.

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Journal

#48Fiber-coupled surface-emitting photonic crystal band edge laser for biochemical sensor applications

Sunghwan Kim, Jeongkug Lee, Heonsu Jeon, Hyo Jin Kim

Applied Physics Letters

Demonstrates a Γ-point photonic crystal band-edge laser with simple butt-end fiber coupling for refractive-index sensing, achieving ~10⁻³ index resolution in an ultracompact, alignment-free platform.

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Journal

#47Gan light-emitting diode with monolithically integrated photonic crystals and angled sidewall deflectors for efficient surface emission

Joonhee Lee, Sungmo Ahn, Sihan Kim, Dong-Uk Kim, Heonsu Jeon, Seung-Jae Lee, Jong Hyeob Baek

Applied Physics Letters

Integrates a 2D photonic crystal pattern on the sapphire substrate with angled sidewall deflectors to redirect guided photons, yielding ~2× total and 2.5× surface-normal emission improvements over conventional GaN LEDs.

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Journal

#46Gan-based light-emitting diodes directly grown on sapphire substrate with holographically generated two-dimensional photonic crystal patterns

Joonhee Lee, Dong-Ho Kim, Jaehoon Kim, Heonsu Jeon

Current Applied Physics

Integrating submicron-period 2D photonic crystal patterns at the GaN–sapphire interface via holography and ICP etching enhances bottom-emitting GaN LED efficiency.

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Journal

#45Photonic band structure calculations for metal-clad two-dimensional photonic crystal slab

Jong-Ho Choe, Q-Han Park, Heonsu Jeon

Current Applied Physics

FDTD and PWE studies of metal-clad 2D photonic crystal slabs show how metallic cladding mimics odd modes of dielectric air-bridge slabs while allowing reduced thickness.

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2008

Journal

#44Effect of metallic slab cladding on photonic crystal band structures

Jong-ho Choe, Q-Han Park, Heonsu Jeon

Journal of the Korean Physical Society

Analyzes square and triangular lattice photonic crystal slabs with PEC and real metal cladding via PWE and FDTD, showing significant band modifications particularly near the Γ point.

Journal

#42Photonic crystal alloys: a new twist in controlling photonic band structure properties

Hee Jin Kim, Dong-Uk Kim, Young-Geun Roh, Jaejun Yu, Heonsu Jeon, Q-Han Park

Optics Express

Introduces photonic crystal alloys mixing silica and alumina spheres in diamond-lattice microwave PCs, showing monotonic L-point band-edge shifts with minimal bowing consistent with virtual crystal approximation.

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Journal

#41Laterally graded porous silicon optical filter fabricated by diffusion-limited etch process

Kyungwook Hwang, Sihan Kim, Yeonsang Park, Heonsu Jeon, Jaewook Jeong

Applied Optics

Laterally graded porous silicon optical filters are produced via diffusion-limited anodic etching controlled by mask design, yielding ~60 nm tunability around 1550 nm with ~3 nm bandwidth.

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Journal

#40Gan light-emitting diode with deep-angled mesa sidewalls for enhanced light emission in the surface-normal direction

Jae-Soong Lee, Joonhee Lee, Sunghwan Kim, Heonsu Jeon

IEEE Transactions on Electron Devices

GaN LEDs with deep, angled mesa sidewalls redirect laterally guided photons toward the surface-normal direction, yielding over twofold light-output enhancement for ~30° angles, confirmed by ray-optics simulation and electroluminescence measurements.

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2007

Journal

#43Ordered arrays of zno nanorods grown on periodically polarity-inverted surfaces

M. S. Kim, J. S. Ha, Y. G. Roh, H. Jeon

Applied Physics Letters

Highly ordered ZnO nanorod arrays grown on polarity-inverted templates provide controlled ZnO nanostructures for optical/electronic devices.

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Journal

#39Fabrication of reflective gan mesa sidewalls for the application to high extraction efficiency LEDs

Jae-Soong Lee, Joonhee Lee, Sunghwan Kim, Heonsu Jeon

physica status solidi (c)

GaN LEDs with angled, reflective mesa sidewalls exhibit smooth surfaces (~2 nm roughness) and redirect laterally guided photons, boosting total emission over threefold for ~30° sidewall angles.

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Journal

#38Butt-end fiber coupling to a surface-emitting γ-point photonic crystal band edge laser

Yeonsang Park, Sunghwan Kim, Chaeyoung Moon, Heonsu Jeon, Hyo Jin Kim

Applied Physics Letters

Demonstrates a compact fiber coupling scheme for Γ-point photonic crystal band-edge lasers achieving up to 30% coupling efficiency with simple butt-end alignment.

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Journal

#37Fluorescence amplification using colloidal photonic crystal platform in sensing dye-labeled deoxyribonucleic acids

Hee Jin Kim, Sunghwan Kim, Heonsu Jeon, Jangseok Ma, Soo Hyung Choi, Soosuk Lee, Christopher Ko, Wounjhang Park

Sensors and Actuators B: Chemical

Self-assembled silica colloidal photonic crystals used as biosensing platforms show fluorescence enhancements of two orders of magnitude for dye-labeled DNA hybridization.

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Journal

#35Photonic crystal cavity lasers patterned by a combination of holography and photolithography

Chi-O Cho, Joonhee Lee, Yeonsang Park, Young-Geun Roh, Heonsu Jeon, In Kim

IEEE Photonics Technology Letters

Air-bridge InGaAsP photonic crystal cavity lasers fabricated via combined laser holography and photolithography achieve lasing despite structural imperfections, supported by simulations showing mode selectivity benefits.

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Journal

#34In-plane multichannel drop filter built in a homogeneous two-dimensional photonic crystal

Young-Geun Roh, Sungjoon Yoon, Heonsu Jeon, Sangin Kim, Hanjo Lim

Journal of the Korean Physical Society

Experimental demonstration of in-plane multichannel photonic-crystal drop filters with ~20 dB selectivity and ~17 MHz bandwidth, consistent with FDTD simulations and improved drop efficiency via photon recycling.

2006

Journal

#36Gan surface-emitting laser with monolithic cavity-folding mirrors

Jae-Soong Lee, Joonhee Lee, Heonsu Jeon

IEEE Journal of Selected Topics in Quantum Electronics

Demonstrates a GaN-based surface-emitting laser using monolithic cavity-folding mirrors with optically pumped operation and analysis via FDTD simulations.

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Journal

#33FDTD simulation for light extraction in a gan-based LED

W. J. Choi, Q-Han Park, Dongho Kim, Heonsu Jeon, Cheolsoo Sone, Yongjo Park

Journal of the Korean Physical Society

Large-scale 3D FDTD simulations of square-lattice photonic crystal patterns on GaN LEDs reveal optimal structures for enhanced light extraction consistent with experiments.

Journal

#32Photonic crystal superprism based on negative refraction

H. J. Kim, Q-Han Park, Heonsu Jeon, Youngho Choe

Journal of the Korean Physical Society

Improves photonic crystal superprism resolution by hybrid dispersion with negative refraction, validated via FDTD simulations at telecom wavelengths.

Journal

#31Mode-stabilized operation in a microlens-integrated 980 nm vertical-cavity surface-emitting laser

Si-Hyun Park, Sangyeon Lee, Heonsu Jeon

Optical Review

Investigates microlens-integrated 980 nm VCSELs achieving stable single-mode operation through microlens-induced mode stabilization, confirmed by numerical modal calculations.

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Journal

#30Gan-based light-emitting diode structure with monolithically integrated sidewall deflectors for enhanced surface emission

Jae-Soong Lee, Joonhee Lee, Sunghwan Kim, Heonsu Jeon

IEEE Photonics Technology Letters

Angled sidewall deflectors integrated monolithically into GaN LED mesas redirect photons toward the surface, boosting emission strength by more than threefold.

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Journal

#29Comparison of structural and optical properties of inas quantum dots grown by migration-enhanced molecular-beam epitaxy and conventional molecular-beam epitaxy

N. K. Cho, S. P. Ryu, J. D. Song, W. J. Choi, J. I. Lee, Heonsu Jeon

Applied Physics Letters

Compares InAs quantum dots grown by migration-enhanced vs conventional MBE, showing thinner wetting layers, larger uniform dots, and better optical properties for the enhanced method.

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Journal

#28Near-field photoluminescence study of inas/algaas quantum-dot-based nanoclusters: band-filling effect

Young-Jun Yu, Haneol Noh, Mun-Heon Hong, In-Taek Jeong, Jong-Chun Woo, Yeonsang Park, Heonsu Jeon, Wonho Jhe

Japanese Journal of Applied Physics

Near-field spectroscopy of InAs/AlGaAs quantum-dot nanoclusters reveals band-filling effects with up to 20 meV blueshift as excitation power increases, mapping luminescence energy shifts in real space.

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Journal

#27Microchip-type ingan vertical external-cavity surface-emitting laser

Si-Hyun Park, Heonsu Jeon

Optical Review

Fabricated microchip-type InGaN VECSELs with integrated microlenses, showing optimized curvature for low threshold, high slope efficiency, and stable multimode operation consistent with Gaussian beam theory.

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2005

Journal

#26Enhanced light extraction from gan-based light-emitting diodes with holographically generated two-dimensional photonic crystal patterns

Dong-Ho Kim, Chi-O Cho, Yeong-Geun Roh, Heonsu Jeon, Yoon Soo Park, Jaehee Cho, Jin Seo Im, Cheolsoo Sone, Yongjo Park, Won Jun Choi, Q-Han Park

Applied Physics Letters

GaN LEDs integrated with holographically generated two-dimensional photonic crystal patterns exhibit over twofold light output enhancement, consistent with 3D FDTD simulations.

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Journal

#25Photonic crystal band edge laser array with a holographically generated square-lattice pattern

Chi-O Cho, Jaewook Jeong, Joonhee Lee, Heonsu Jeon, In Kim, Dong Hoon Jang, Yoon Soo Park, Jong Chun Woo

Applied Physics Letters

Square-lattice photonic crystal band-edge laser arrays fabricated by laser holography exhibit large-area, high-throughput lasing with predictable mode shifts along the array.

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Journal

#24Photonic bandgap engineering in mixed colloidal photonic crystals

Hee Jin Kim, Young-Geun Roh, Heonsu Jeon

Japanese Journal of Applied Physics

Mixed silica/polystyrene colloidal photonic crystals show tunable bandgaps with L-point red shifts, matching effective-medium predictions.

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2004

Journal

#23Experimental verification of cross talk reduction in photonic crystal waveguide crossings

Young-Geun Roh, Sungjoon Yoon, Heonsu Jeon, Seung-Ho Han, Q-Han Park

Applied Physics Letters

Demonstrates resonant-cavity-enhanced photonic crystal waveguide crossings with up to −30 dB cross-talk reduction at resonance, validated by microwave experiments and simulations.

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Journal

#22Effects of microlens curvature on the operation of microlens-integrated extended cavity gan VCSELs

Si-Hyun Park, Heonsu Jeon

physica status solidi (a)

Extended-cavity GaN VCSELs with integrated microlenses exhibit curvature-dependent performance, with an optimum radius giving the lowest threshold and highest slope efficiency while maintaining single-mode lasing.

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Journal

#21Double-layer antireflection coating design for one-dimensional photonic crystals

Yeonsang Park, Heonsu Jeon

Journal of Lightwave Technology

Develops theoretical formalism for double-layer antireflection coatings tailored to 1D photonic crystals, with numerical validation on GaAs/AlAs-oxide structures.

Journal

#20Geometric improvements of light transmission at photonic crystal waveguide bends

S.-H. Han, Q.-Han Park, Y. S. Park, Y. Roh, H. S. Jeon

Journal of the Korean Physical Society

Evaluates three geometric strategies for photonic crystal waveguide bends via 3D FDTD, showing hybrid bandgap/index-guided structures minimize radiative losses.

Journal

#19Propagation properties in a 2 + 1-dimensional hybrid photonic crystal waveguide

S. H. Han, Q. Han Park, Y. S. Park, Y. Roh, Heonsu Jeon

Journal of the Korean Physical Society

Numerical study of dressed slab photonic crystal waveguides with omni-directional mirrors shows reduced radiative loss, detailed defect/stop-band/group-velocity characteristics, and low-leakage guidance possibilities.

Journal

#18Photonic crystal slab waveguides fabricated by the combination of holography and photolithography

Chi-O Cho, Young-Geun Roh, Yeonsang Park, Heonsu Jeon, Beom-Seok Lee, Hye-Won Kim, Young-Ho Choe

Japanese Journal of Applied Physics

Air-bridge 2D photonic crystal waveguides fabricated via holography and photolithography exhibit guiding through straight and 90°-bent sections at 1.55 μm with propagation loss ~40 cm⁻¹.

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Journal

#17Towards nano-waveguides

Chi-O Cho, Young-Geun Roh, Yeonsang Park, Jae-Soong I, Heonsu Jeon, Beom-Seok Lee, Hye-Won Kim, Young-Ho Choe, Mingyu Sung, J.C. Woo

Current Applied Physics

Explores design concepts for nanoscale waveguides using photonic-crystal and dielectric structures, discussing confinement mechanisms and integration prospects.

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Journal

#16Optimal design for one-dimensional photonic crystal waveguide

Jae-Soong I, Yeonsang Park, Heonsu Jeon

Journal of Lightwave Technology

Proposes design logic for 1D photonic crystal waveguides based on effective wavelength projections and demonstrates functionality via numerical calculations on GaAs-AlAs oxide structures.

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2003

Journal

#15Room-temperature gan vertical-cavity surface-emitting laser operation in an extended cavity scheme

Si-Hyun Park, Jaehoon Kim, Heonsu Jeon, Tan Sakong, Sung-Nam Lee, Suhee Chae, Y. Park, Changhyun Jeong, Geun-Young Yeom, Yong-Hoon Cho

Applied Physics Letters

An extended-cavity GaN VCSEL with integrated microlens and high-reflection mirrors achieves room-temperature lasing at ~160 kW/cm² excitation.

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Journal

#14Theory of the mode stabilization mechanism in concave-micromirror-capped vertical-cavity surface-emitting lasers

Si-Hyun Park, Yeonsang Park, Heonsu Jeon

Journal of Applied Physics

Theoretical study of mode stabilization in oxide-confined CMC-VCSELs identifies micromirror thickness periodicity and optimal curvature structures that strongly favor the fundamental transverse mode.

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Journal

#13Enhanced light extraction from organic light-emitting diodes with 2d sio₂/sinₓ photonic crystals

Yong-Rim Do, Y.C. Kim, Y.-W. Song, C.-O Cho, Heonsu Jeon, Y.-J. Lee, S.-H. Kim, Y.-H. Lee

Advanced Materials

Introduces a 2D SiO₂/SiNₓ photonic-crystal layer to mitigate light trapping in OLEDs, improving current–voltage–luminance characteristics and lifetime via enhanced light extraction.

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Journal

#12Photonic crystal waveguides with multiple 90° bends

Young-Geun Roh, Sungjoon Yoon, Sunghwan Kim, Heonsu Jeon, Seung-Ho Han, Q-Han Park, Inkyu Park

Applied Physics Letters

Microwave photonic-crystal waveguides sandwiched between metal plates maintain excellent guiding through multiple 90° bends, with propagation velocity ≈0.47c and bending loss of ~0.1 dB per bend, emphasizing vertical confinement benefits.

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Journal

#11Gaas-based near-infrared omnidirectional reflector

Yeonsang Park, Young-Geun Roh, Chi-O Cho, Heonsu Jeon, Min Gyu Sung, J. C. Woo

Applied Physics Letters

A GaAs/AlAs multilayer stack converted to GaAs/Al2O3 via selective oxidation forms a 1D photonic crystal with omnidirectional reflection below 1 μm, matching simulations across angles and polarizations.

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2002

Journal

#10A dielectric omnidirectional near-infrared reflector

Yeonsang Park, Heonsu Jeon

Journal of the Optical Society of Korea

Theoretical and experimental study of 1.3 μm omnidirectional reflectors using alternating amorphous silicon/silica layers, confirming omnidirectional photonic bandgaps.

Journal

#9Enhanced optical coupling performance in an ingaas photodiode integrated with wet-etched microlens

S.R. Cho, J. Kim, K.S. Oh, S.K. Yang, J.H. Baek, D.H. Jang, T.I. Kim, Heonsu Jeon

IEEE Photonics Technology Letters

Wet-etched microlenses integrated with InGaAs photodiodes enhance optical coupling efficiency and improve alignment tolerance.

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Journal

#8Design, fabrication, and micro-reflectance measurement of a gaas/alas-oxide antireflection film

Yeonsang Park, Joong-Seon Choe, Heonsu Jeon

Journal of the Korean Physical Society

Oxide-based GaAs/AlAs antireflection coatings exhibit low reflectance verified through micro-reflectance measurements.

Journal

#7Microlensed vertical-cavity surface-emitting laser for stable single fundamental mode operation

Si-Hyun Park, Yeonsang Park, Hyeyin Kim, Heonsu Jeon, Seong Mo Hwang, Jeong Kwan Lee, Seung Ho Nam, Byeong Cheon Koh, J. Y. Sohn, D. S. Kim

Applied Physics Letters

Demonstrates a VCSEL with an integrated microlens that forces lasing into the fundamental mode, ensuring stable single-mode operation over a wide current range.

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2001

Journal

#6One-dimensional photonic crystal waveguide: a frame for photonic integrated circuits

Jae-Soong I, Yeonsang Park, Heonsu Jeon

Journal of the Korean Physical Society

Introduces 1D photonic crystal waveguides optimized for photonic integrated circuits, providing high confinement and tunable propagation.

Journal

#5Refractive sapphire microlenses fabricated by chlorine-based inductively coupled plasma etching

Si-Hyun Park, Heonsu Jeon, Yoon-Joon Sung, Geun-Young Yeom

Applied Optics

Fabricated refractive sapphire microlenses via chlorine-based ICP etching of thermally reflowed photoresist patterns, achieving near-diffraction-limited performance.

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Journal

#4Optical microscope imaging of semiconductor quantum wells

Hyejin Kim, Jaehoon Kim, Heonsu Jeon

Semiconductor Science and Technology

Demonstrates optical microscopy methods to visualize semiconductor quantum wells, detailing contrast mechanisms and imaging limitations for low-dimensional semiconductors.

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2000

Journal

#3Lateral oxidation of alas layers at elevated water vapour pressure using a closed-chamber system

Joong-Seon Choe, Si-Hyun Park, Byung-Doo Choe, Heonsu Jeon

Semiconductor Science and Technology

Closed-chamber lateral oxidation of AlAs at elevated water vapor pressures provides controlled oxide-aperture formation for VCSELs.

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Journal

#2Semiconductor microlenses fabricated by one-step wet etching

Yu-Sik Kim, Jaehoon Kim, Joong-Seon Choe, Young-Geun Roh, Heonsu Jeon, J.C. Woo

IEEE Photonics Technology Letters

Diffusion-limited Br₂ chemical etching yields high-quality GaAs/InP microlenses with ~30 μm diameter, 91/36 μm focal lengths, and sub-10 nm roughness, offering a simple, high-yield fabrication route for micro-optics.

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Journal

#112 Nm tunable WDM source using an integrated laser array

B. Pezeshki, A. Mathur, S. Zou, H.-S. Jeon, V. Agrawal, R.L. Lang

Electronics Letters

An integrated four-DFB-laser WDM source with a booster amplifier delivers up to 15 mW fiber-coupled power with 12 nm tuning, leveraging quarter-wave-shifted phase-masks and a two-step regrowth process for cost-effective fabrication.

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