Prof. Junsuk Rho Profile

Prof. Junsuk Rho

at Pohang Univ of Science and Technology

SPIE Involvement:

Scholarship Committee | Conference Program Committee | Editorial Board Member: Advanced Photonics Nexus | Editorial Board Member: Photonics Insights | Author

Publications (65)

SPIE Journal Paper | 14 November 2024 Open Access

Deep-learning-driven end-to-end metalens imaging

Joonhyuk Seo, Jaegang Jo, Joohoon Kim, Joonho Kang, Chanik Kang, Seong-Won Moon, Eunji Lee, Jehyeong Hong, Junsuk Rho, Haejun Chung

AP, Vol. 6, Issue 06, 066002, (November 2024) https://doi.org/10.1117/12.10.1117/1.AP.6.6.066002

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SPIE Journal Paper | 26 June 2024 Open Access

Iso-propagation vortices: a breakthrough in optical communication technology

Cherry Park, Junsuk Rho

AP, Vol. 6, Issue 03, 030503, (June 2024) https://doi.org/10.1117/12.10.1117/1.AP.6.3.030503

KEYWORDS: Quantum optical communication, Beam divergence, Telecommunications, Multiplexing, Free space optics, Optical transmission, Atmospheric propagation, Quantum receivers, Quantum numbers, Quantum channels

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Proceedings Article | 11 June 2024 Presentation

Low-cost and scalable manufacturing of optical metasurfaces in the visible using engineered optical materials

Junsuk Rho

Proceedings Volume PC12990, PC129901C (2024) https://doi.org/10.1117/12.3014260

KEYWORDS: Manufacturing, Optics manufacturing, Optical engineering, Printing, Dielectrics, Atomic layer deposition, Zirconium dioxide, Visible radiation, Refractive index, Holography

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SPIE Journal Paper | 7 June 2024 Open Access

Structural coloration: advancements and challenges

Dohyun Kang, Junsuk Rho

PI, Vol. 3, Issue 02, C04, (June 2024) https://doi.org/10.1117/12.10.3788/PI.2024.C04

KEYWORDS: Nanoimprint lithography, Near eye displays, Localized surface plasmon resonances, Fabrication, Design, Commercialization, Nanostructures, Humidity, Sensors, Light emitting diodes

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Proceedings Article | 6 June 2024 Poster

Humidity-sensitive polyvinyl alcohol metasurfaces for realizing advanced optical security

Byoungsu Ko, Trevon Badloe, Younghwan Yang, Junsuk Rho

Proceedings Volume PC12990, PC129901Z (2024) https://doi.org/10.1117/12.3022774

KEYWORDS: Polyvinyl alcohol, Information security, Humidity, Relative humidity, Printing, Platinum, Nanoimprint lithography, Holography, Computer security, Thin films

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Proceedings Article | 13 March 2024 Presentation

Metasurface for full-space structured light and dynamic imaging system for compact nanophotonic device

Yeseul Kim, Junsuk Rho, Trevon Badloe, Joohoon Kim, Inki Kim

Proceedings Volume PC12897, PC128970A (2024) https://doi.org/10.1117/12.3001376

KEYWORDS: Structured light, Nanophotonics, Imaging systems, Point clouds, Optical components, Virtual reality, System integration, Structural design, Sensing systems, Polarization

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Proceedings Article | 13 March 2024 Presentation

Wavelength-multiplexed orbital angular momentum meta-holography

Jaehyuck Jang, Junsuk Rho, Seong-Won Moon, Joohoon Kim

Proceedings Volume PC12897, PC1289708 (2024) https://doi.org/10.1117/12.3001275

KEYWORDS: Angular momentum, Holography, Volume holography, Video coding, Video, Switching, Holograms, Design and modelling, Crosstalk, Color

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Proceedings Article | 13 March 2024 Poster

Nonlocal metasurface fabricated by quantum dot embedded resin printing

Huichang Yun, Minsu Jeong, Junsuk Rho

Proceedings Volume PC12896, PC128961H (2024) https://doi.org/10.1117/12.3002154

KEYWORDS: Quantum dots, Nanolithography, Printing, Polarization, Emission wavelengths, Refractive index, Nanostructures, Flat optics, Titanium dioxide, Titanium

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Proceedings Article | 13 March 2024 Presentation

Design, materials, and manufacturing of optical metasurfaces for flat optics, devices, and applications

Jeong-Geun Yun, Hyunjung Kang, Dohyun Kang, Joohoon Kim, Gyeongtae Kim, Junsuk Rho

Proceedings Volume PC12897, PC128970F (2024) https://doi.org/10.1117/12.2691989

KEYWORDS: Waveguides, Augmented reality, Design and modelling, Glasses, Displays, Wave propagation, Refractive index, Optical gratings, Optical design, Optical components

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Proceedings Article | 13 March 2024 Presentation

Nanoimprinted photonic crystal using quantum dot embedded resin

Minsu Jeong, Junsuk Rho

Proceedings Volume PC12896, PC128960U (2024) https://doi.org/10.1117/12.3001301

KEYWORDS: Photonic crystals, Quantum dots, Photonic nanostructures, Composite resins, Titanium dioxide, Resonators, Quantum limits, Photons, Nanophotonics, Nanoparticles

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Proceedings Article | 13 March 2024 Poster

Enhanced upconversion vortex emission using bound state in continuum

Minsu Jeong, Junsuk Rho

Proceedings Volume PC12896, PC128961G (2024) https://doi.org/10.1117/12.3001304

KEYWORDS: Photons, Upconversion, Near infrared, Polarization, Visible radiation, Photonic crystals, Photon polarization, Photoluminescence, Phase distribution, Optical properties

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Proceedings Article | 12 March 2024 Presentation + Paper

3D laser-nanoprinted meta-optics: a breakthrough photonic platform for wavefront shaping and molecular sensing

Haoran Ren, Chenhao Li, Andreas Aigner, Jaehyuck Jang, Junsuk Rho, Markus Schmidt, Stefan Maier

Proceedings Volume 12901, 1290109 (2024) https://doi.org/10.1117/12.3008920

KEYWORDS: Structured light, Quantum light, Wavefronts, Molecular photonics, Laser applications, Molecular lasers, 3D surface sensing, Structured optical fibers, Wavefront sensors, Optical fibers

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Proceedings Article | 6 October 2023 Poster

Gap-plasmon-driven liquid-crystal integrated chiral metasurface for intensity tunable hologram at the visible frequencies

Younghwan Yang, Hongyoon Kim, Junsuk Rho

Proceedings Volume PC12646, PC126461N (2023) https://doi.org/10.1117/12.2672556

KEYWORDS: Liquid crystals, Reflection, Polarization, Holography, Holograms, Dichroic materials, Split ring resonators, Polarized light, Nanostructures, Visible radiation

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Proceedings Article | 6 October 2023 Poster

Observing sequential aspects of metasurface with deep neural networks

Jaebum Noh, Younghwan Yang, Junsuk Rho

Proceedings Volume PC12655, PC1265517 (2023) https://doi.org/10.1117/12.2676322

KEYWORDS: Neural networks, Design and modelling, Refractive index, Visible radiation, Reflection, Optical transmission, Optical properties, Network architectures, Nanophotonics, Holograms

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Proceedings Article | 6 October 2023 Poster

Structural coloration using bandgap engineered, low-optical losses hydrogenated amorphous silicon

Younghwan Yang, Jaehyuck Jang, Chunghwan Jung, Trevon Badloe, Junsuk Rho

Proceedings Volume PC12646, PC126461O (2023) https://doi.org/10.1117/12.2673186

KEYWORDS: Amorphous silicon, Titanium dioxide, Refractive index, Gallium nitride, Visible radiation, Toxicity, Silicon nitride, Semiconductors, Scattering, Reflection

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Proceedings Article | 5 October 2023 Presentation

Perspectives of design, materials, and fabrication for metasurfaces

Junsuk Rho

Proceedings Volume PC12648, PC126480G (2023) https://doi.org/10.1117/12.2672096

KEYWORDS: Design and modelling, Materials processing, Printing, Visible radiation, Photonics, Holography, Amorphous silicon, Zirconium dioxide, Ultraviolet radiation, Physics

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Proceedings Article | 5 October 2023 Presentation

Deep learning enabled control of active metasurface antenna

Jaebum Noh, Junsuk Rho

Proceedings Volume PC12655, PC126550S (2023) https://doi.org/10.1117/12.2676330

KEYWORDS: Antennas, Neural networks, Deep learning, Education and training, PIN photodiodes

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Proceedings Article | 5 October 2023 Poster

Transparent radiative cooling with non-diffractive perforated-mirror structure

Byoungsu Ko, Jaebum Noh, Junsuk Rho

Proceedings Volume PC12653, PC126530D (2023) https://doi.org/10.1117/12.2676289

KEYWORDS: Reflection, Transparency, Reflectors, Visible radiation, Solar energy, Mirrors, Visibility, Solar energy systems, Light absorption, Energy efficiency

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Proceedings Article | 4 October 2023 Presentation

Principle and applications of metasurfaces to enhance the spin Hall effect of light

Junsuk Rho

Proceedings Volume PC12647, PC1264715 (2023) https://doi.org/10.1117/12.2675535

KEYWORDS: Polarized light, Sensing systems, Photonics, Refraction, Reflection, Precision measurement, Polarization, Phase modulation, Optical properties, Nanophotonics

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Proceedings Article | 4 October 2023 Presentation

Bandgap engineered low-loss a-Si:H for efficient dielectric metasurfaces at visible frequencies

Younghwan Yang, Gwanho Yoon, Minkyung Kim, Dasol Lee, Junsuk Rho

Proceedings Volume PC12646, PC126460F (2023) https://doi.org/10.1117/12.2672557

KEYWORDS: Dielectrics, Refractive index, Phase measurement, Optical components, Miniaturization, Incident light, Engineering, Chemical vapor deposition, Amorphous silicon

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Proceedings Article | 4 October 2023 Presentation

Humidity-responsive full color nano-pixels via nanoporous Fabry-Pérot structure

Jaekyung Kim, Byoungsu Ko, Younghwan Yang, Junsuk Rho

Proceedings Volume PC12646, PC126460B (2023) https://doi.org/10.1117/12.2677174

KEYWORDS: Humidity, Silver, Polyvinyl alcohol, Nanoparticles, Metals, Toxicity, Optical properties, Nanoimprint lithography, Molecules, Magnetism

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Proceedings Article | 4 October 2023 Poster

Electrochemically modulated structural color filter with polarization sensitive transmission

Jaekyung Kim, Junsuk Rho

Proceedings Volume PC12647, PC126471V (2023) https://doi.org/10.1117/12.2677179

KEYWORDS: Optical filters, Polarization, Optical transmission, Gold, Mirrors, Refractive index, Modulation, Electrooptic modulation, Electro optics, Tunable filters

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Proceedings Article | 4 October 2023 Presentation

Humidity-responsive tunable metasurfaces with nanoimprinted structural polyvinyl alcohol

Byoungsu Ko, Trevon Badloe, Younghwan Yang, Junsuk Rho

Proceedings Volume PC12646, PC126460G (2023) https://doi.org/10.1117/12.2676288

KEYWORDS: Polyvinyl alcohol, Optical components, Humidity, Relative humidity, Nanostructures, Visible radiation, Structural design, Polymers, Optical properties, Optical image encryption

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Proceedings Article | 28 September 2023 Presentation

Cascade domino lithography for extreme photon squeezing at the sub-nanometer scale

Junsuk Rho

Proceedings Volume PC12657, PC1265707 (2023) https://doi.org/10.1117/12.2676403

KEYWORDS: Quantum plasmonics, Lithography, Quantum squeezing, Quantum enhancement, Surface enhanced Raman spectroscopy, Raman spectroscopy, Quantum control, Gold, Excitons, Control systems

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Squeezing light into deep sub-wavelength volumes or even into few-nanometer gaps has led to the investigation of interesting phenomena, including strong coupling, quantum plasmonics, nonlinearity enhancement, nonlocality, and molecular junctions. Bowtie nanoantennas, as a common configuration for plasmonic nanocavity, have been extensively studied owing to their great enhancement of the localized field. The enhancement rapidly increases as the tips become sharper and the gap becomes narrower. However, every effort paid to increase the extreme sharpness and nanomete rprecision of less than 10 nm gaps result in the downfall of fabrication throughput, since it relies on the probability of achieving one satisfactory piece out of the many fabricated. Here, an intuitive “fall-to-rise” schemes are proposed and experimentally validated using cascade domino lithography (CDL) and capillary-force-induced collapse lithography(CCL). In this report, we successfully establish a controllable lithography method of making extremely sharp bowtie-shaped plasmonic nanocavity with sub-1nm radius curvature reaching the size of a gold nanocluster as well as a single-digit-nanometer gap between such sharp tips. By controlling falling mechanisms of photoresist mask structures, a facileroute to fabricate sub-10 nm plasmonic nanocavity with high yield is provided. In addition, a proof-of-concep tapplication in surface enhanced Raman spectroscopy (SERS) is demonstrated. The numerically calculated intensity enhancement is over 2.2×10^4 with the confined mode volume below 7.14×10^-6 λ^3, the measured average Raman enhancement factor is of the order of 10^6 with the calculated local Raman enhancement factor over 10^8 promising for single-molecular level sensing applications. Furthermore, such sharp plasmonic nanocavity is used to probe and control localized excitons at room temperature, which offers new strategies for active quantum nano-optical devices.Atomically thin semiconductors, WSe2, are coated on top of plasmonic nanocavity and Au tip for tip-enhanced photo luminescence (TEPL) spectroscopy is added to induce tensile strain in the nanoscale region to create robust localized exciton at the hotspot region. Such an approach provides a systematic way to control localized quantum light.This controlling mechanism of nanostructures falling opens up an unexplored gateway towards conquering the limitations of exploring the realm of plasmonics down to the sub-nanometer regime.

SPIE Journal Paper | 17 July 2023 Open Access

Advent of torsional optomechanics from Beth’s legacy

Jaehyuck Jang, Jungho Mun, Junsuk Rho

AP, Vol. 5, Issue 04, 040501, (July 2023) https://doi.org/10.1117/12.10.1117/1.AP.5.4.040501

KEYWORDS: Angular momentum, Optomechanical design, Acoustics, Quantum spin, Quantum fields, Quantum optics experiments, Quantum light, Quantum detection, Printed circuit board testing, Pendulums

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SPIE Journal Paper | 4 July 2023 Open Access

Optical Orbital Angular Momentum: Thirty Years and Counting

Guixin Li, Junsuk Rho, Xiao-Cong Yuan

AP, Vol. 5, Issue 03, 030101, (July 2023) https://doi.org/10.1117/12.10.1117/1.AP.5.3.030101

KEYWORDS: Angular momentum, Quantum photonics, Structured light, Quantum light generation, Phase interferometry, Pendulums, Optical parametric oscillators, Optical interconnects, Multiplexing, Lithium

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SPIE Journal Paper | 7 June 2023 Open Access

Writing nanometer-scale structures for centimeter-scale color printing

Younghwan Yang, Trevon Badloe, Junsuk Rho

AP, Vol. 5, Issue 03, 030501, (June 2023) https://doi.org/10.1117/12.10.1117/1.AP.5.3.030501

KEYWORDS: Fabrication, Multiphoton lithography, Color printing, Spatial resolution, RGB color model, Pixel resolution, Photoresist materials, Optical filters, Nanoimprint lithography, Lithography

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SPIE Journal Paper | 22 May 2023 Open Access

Emerging low-cost, large-scale photonic platforms with soft lithography and self-assembly

Hyunjung Kang, Dohyeon Lee, Younghwan Yang, Dong Kyo Oh, Junhwa Seong, Jaekyung Kim, Nara Jeon, Dohyun Kang, Junsuk Rho

PI, Vol. 2, Issue 02, R04, (May 2023) https://doi.org/10.1117/12.10.3788/PI.2023.R04

KEYWORDS: Block copolymers, Particles, Nanoimprint lithography, Printing, Lithography, Fabrication, Polymers, Gold, Optical lithography, Copyright

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Proceedings Article | 17 March 2023 Presentation

Dynamic metasurfaces for holography and structural coloration

Junsuk Rho

Proceedings Volume PC12432, PC124320V (2023) https://doi.org/10.1117/12.2647173

KEYWORDS: Refractive index, Holography, Liquid crystals, Optical filters, Solid state electronics, Information security, Humidity, Holograms, Gas sensors, Video

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Proceedings Article | 17 March 2023 Presentation

Multiplexing molecular spectroscopy via metasurface using plasmonic resonance energy transfer

Hongyoon Kim, Inki Kim, Seungyeon Han, Joohoon Kim, Yangkyu Kim, Inhee Choi, Junsuk Rho, Luke Lee

Proceedings Volume PC12432, PC124320L (2023) https://doi.org/10.1117/12.2647810

KEYWORDS: Plasmonics, Resonance energy transfer, Nanoparticles, Multiplexing, Scattering, Molecular spectroscopy, Absorption, Plasmons, Resonance enhancement, Light scattering

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Proceedings Article | 17 March 2023 Presentation

Deep learning-based glucose sensing robust to sample position error with split ring resonator sensor

Seokho Lee, Trevon Badloe, Younghwan Yang, Junsuk Rho

Proceedings Volume PC12432, PC124320M (2023) https://doi.org/10.1117/12.2648302

KEYWORDS: Refractive index, Data processing, Water, Visualization, Optical properties, Scattering, Optical signal processing, Nanostructures, Information visualization, Holograms

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Proceedings Article | 14 March 2023 Poster

Disordered plasmonic nanoparticle-driven etalon for colorimetric gas sensor

Chunghwan Jung, Jaehyuck Jang, Junsuk Rho

Proceedings Volume 12417, 124171A (2023) https://doi.org/10.1117/12.2658444

KEYWORDS: Plasmonics, Gas sensors, Fabry–Perot interferometers, Ultrafast phenomena, Nanoparticles, Sensors, Resonators, Refractive index, Reflectivity, Optical properties

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Proceedings Article | 9 March 2023 Poster + Paper

Tapered fiber-based shear force scanning photoacoustic microscopy

Moongyu Han, Byullee Park, Hongyoon Kim, Jinhee Yoo, Dong Kyo Oh, Seongwon Moon, Joongho Ahn, Hae Gyun Lim, Inki Kim, Hyung Ham Kim, Junsuk Rho, Chulhong Kim

Proceedings Volume 12379, 123791H (2023) https://doi.org/10.1117/12.2648171

KEYWORDS: Gold, Near field, Glasses, Photoacoustic microscopy, Aluminum, Photoacoustic spectroscopy, Near field optics, Image resolution, Wave propagation, Ultrasonography

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SPIE Journal Paper | 21 December 2022 Open Access

Computation at the speed of light: metamaterials for all-optical calculations and neural networks

Trevon Badloe, Seokho Lee, Junsuk Rho

AP, Vol. 4, Issue 06, 064002, (December 2022) https://doi.org/10.1117/12.10.1117/1.AP.4.6.064002

KEYWORDS: Artificial neural networks, Photonic metamaterials, Optical metamaterials, Design and modelling, Reflection, Edge detection, Education and training, Computing systems, Image processing, Copyright

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Proceedings Article | 4 October 2022 Presentation

Suppressing optical losses of hydrogenated amorphous silicon for dielectric metasurfaces working at the visible frequencies, and revealing its structural disorder. (Conference Presentation)

Younghwan Yang, Gwanho Yoon, Sunghak Park, Ki Tae Nam, Junsuk Rho

Proceedings Volume PC12202, PC1220206 (2022) https://doi.org/10.1117/12.2632722

KEYWORDS: Dielectrics, Visible radiation, Amorphous silicon, Refractive index, Plasma enhanced chemical vapor deposition, Titanium dioxide, Silicon, Gallium nitride, Semiconductors, Plasma

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