A5008580268- Random lasers and scattering media
- Optical Coherence Tomography Applications
- Catalytic Processes in Materials Science
- Photoacoustic and Ultrasonic Imaging
- Catalysis and Oxidation Reactions
- Neural Networks and Reservoir Computing
- Optical Imaging and Spectroscopy Techniques
- Photonic Crystals and Applications
- Orbital Angular Momentum in Optics
- Terahertz technology and applications
- Laser Material Processing Techniques
- Electrocatalysts for Energy Conversion
- Industrial Gas Emission Control
- Laser and Thermal Forming Techniques
- Nanomaterials for catalytic reactions
- Catalysis and Hydrodesulfurization Studies
- Synthesis and properties of polymers
- Neural dynamics and brain function
- Optical Polarization and Ellipsometry
- Quantum optics and atomic interactions
- Silicone and Siloxane Chemistry
- Advanced Optical Imaging Technologies
- Photonic and Optical Devices
- Advanced Fluorescence Microscopy Techniques
- Additive Manufacturing Materials and Processes
Institute for Basic Science
2017-2019
Korea University
2015-2018
Abstract Thick biological tissues give rise to not only the multiple scattering of incoming light waves, but also aberrations remaining signal waves. The challenge for existing optical microscopy methods overcome both problems simultaneously has limited sub-micron spatial resolution imaging shallow depths. Here we present an coherence method that can identify waves incident and reflected from samples separately, eliminate such even in presence scattering. proposed records time-gated...
We demonstrate selective pump focusing for highly isolated single-mode lasers in microdisk and microring cavities, achieve lasing action from a cavity underneath scattering medium. The spatial profile of the pumping light evolves by an iterative feedback process is optimized to maximize field overlap with selected mode. high order mode selectivity resolving power are obtained multimode presence significant modal overlaps. As result adaptive optical pumping, we successfully efficient energy...
In complex media, light waves are diffused both in space and time due to multiple scattering, its intensity is attenuated with the increase of propagation depth. this paper, we propose an iterative wavefront shaping method for enhancing time-gated reflection intensity, which leads efficient energy delivery a target object embedded highly scattering medium. We achieved over 10 times enhancement reflectance at specific flight demonstrated focusing object. Since proposed does not require matrix...
Gold has rarely been utilized as a catalytic component because of its poor affinity to chemical species. It is however known that nanosized gold particles promote the dissociation oxygen or hydrogen. In this study, alumina-supported metal oxide catalysts were prepared by impregnation method and applied methanol oxidation. The dispersion form size observed transmission electron microscopy (TEM). results, maximum activity was obtained over ZnO/Al2O3 catalyst, optimum loading 4 wt%....
In many complex physical phenomena such as wave propagation in scattering media, the process of interest often cannot be easily distinguished from other processes because only total combined is accessible. This makes it difficult to extract precise knowledge each subprocess. Here, we derive an analytic expression describing way eigenchannel coupling distributes its energy individual subprocesses, with partial information on subprocess average eigenvalue 〈τ〉 and enhancement factor η. We found...
Light waves propagating through complex biological tissues are spatially spread by multiple light scattering, and this limits the working depth in optical bioimaging, phototherapy, optogenetics. Here, we propose iterative phase conjugation of time-gated backscattered for enhancing energy delivered to a target object embedded scattering medium. We demonstrate enhancement hidden behind 200-µm-thick mouse skull more than ten times comparison with initial random input. The maximum was reached...
Bimetallic Pt-Au catalysts supported on ZnO/Al2O3 were prepared by incipient wetness impregnation (IW-IMP) method with different pretreatment conditions such as flow velocity, calcination temperature, and heating rate under H2 during the procedure, characterized X-ray diffraction (XRD), CO chemisorption, scanning transmission electron microscopy (STEM) equipped energy dispersive spectroscopy (EDS). Furthermore, catalytic activity for complete oxidation of toluene was measured using a reactor...
The alloy catalyst has been widely used because it will be able to improve the activity and selectivity of single metal in a given chemical reaction. In this study, preparation characteristics nanosized Pt Au particles on alumina their catalytic were described. Nanosized Pt–Au catalysts prepared by impregnation (IMP) method deposition (DP) using or ZnO/Al 2 O 3 as support. size observed transmission electron microscopy (TEM), energy dispersive spectroscope (EDS), X-ray diffraction (XRD)....
To exploit photonics technologies for in vivo studies life science and biomedicine, it is necessary to efficiently deliver light energy the target objects embedded deep within complex biological tissues. However, waves diffuse randomly inside media due multiple scattering, only a small fraction reaches object. Here we present method counteract random diffusion focus 'snake-like' multiple-scattered target. realize this, experimentally identified time-gated reflection eigenchannels that have...
When light propagates through a scattering media, energy is exponentially attenuated due to random diffusion by multiple scattering. Here, we present method focus the target deeply embedded in medium control of time-gated scattered waves. In comparison with case diffusion, could demonstrate 10-fold enhancement delivery rat skull.
We present an approach that maintains full optical resolution in imaging deep within scattering media. Imaging depth of 11.5 times the mean free path was achieved with near-diffraction-limit 1.5 μm.
Thick biological tissues give rise to not only the scattering of incoming light waves, but also aberrations remaining unscattered waves. Due inability existing optical imaging methodologies overcome both these problems simultaneously, depth at sub- micron spatial resolution has remained extremely shallow. Here we present an experimental approach for identifying and eliminating even in presence strong multiple scattering. For time-gated complex-field maps reflected waves taken over various...
레이저를 이용한 실리콘 웨이퍼의 어닐링 공정은 반도체 소자의 열 예산을 크게 감소시킬 수 있어 제조 산업에서 관심을 받고 있다. 본 논문에서는 레이저 공정 시 웨이퍼 전 영역에서 발생하는 열적 거동을 예측하기 위한 3차원 수치 해석 기법을 제시하였다. 수치해석 결과, 표면상의 온도 분포는 빔의 중첩에 의한 예열효과에 상당히 영향을 받는 것으로 확인되었다. 내 온도분포 결과를 바탕으로 균일성 평가를 진행한 영역 중 하부(bottom)구간의 중심이 지나가는 균일성이 가장 고르게 나타난다는 것을 확인하였다. 스캔 패턴에 따른 및 응력 분석 라인형 패턴이 더 우수한 균일성과 낮은 응력을 제공하는 확인할 있었다.