Advanced optical imaging techniques and bio/medical applications (첨단 광학 이미징 기술 및 생물학/의학 응용 연구)
Optical microscopes have revolutionized biology and medicine by visualizing small worlds beyond human vision, but still need improved performance or new imaging capabilities. In this regard, we are developing novel optical microscopy methods with a multidisciplinary approach to innovate both the hardware and software of microscopic imaging systems. This includes applying physical, chemical, and engineering principles, as well as computational methods such as deep learning, denoising, deconvolution, and more. We are also interested in independent or collaborative bio-application research made possible by our novel tools.
(1) Super-resolution microscopy (초고분해능 현미경)
Single molecule localization microscopy (SMLM, aka STORM) is a cellular fluorescence imaging technique with revolutionary imaging resolution down to 20 nm (awarded the Nobel Prize in Chemistry 2014). For its broader applicability toward tissue and small animals, Dr. Kim has developed a new STORM platform (obSTORM in Nature Methods 2019) based on oblique light-sheet imaging method. Here at SNU, we are innovating imaging resolution and speed in cell- and tissue-level STORM and discovering new nano-scale biological structure that has never been explored.
Conventional fluorescence image of a cell. Microtubules are stained with dye molecules. Single molecule video acquisition & localization analysis for sparsely excited dye molecules Super-resolution image reconstruction by accumulating all localization data. Design and Analysis of Optical/Mechanical System Microscopy Instrumentation & Imaging Experiments Image Analysis: New Algorithm Development Novel SMLM Methods: AI-based, Volumetric, Functional STORM New Bio/medical Research
(2) High-speed volumetric imaging (고속 3차원 이미징)
While many biological phenomena in living samples occur in three dimensions in real time, it is difficult to visualize them at good spatio-temporal resolution. Based on light-sheet microscopy and computational imaging approaches, we are developing rapid volumetric imaging tools, targeted for cellular and developmental biology, which enable time-lapse 3D observation of rapidly changing biological events.
Optical/Mechanical Design: In-house Water Chamber for Biological Samples Hardware Interface & Optical Experiments Software-based Image Improvement (Deep learning, deconvolution, etc) Application study: Cellular and Developmental Biology & Other fields
(3) Advanced Optical Imaging Theory and Computational Imaging (고등 광학 이미징 이론 및 전산 이미징)
It may seem simple to focus light or image an object through a “lens”, but its accurate theoretical prediction can be very complicated (or even impossible) for a large numerical aperture lens used in microscopy and lithography. We are interested in utilizing our lab’s theoretical expertise in rigorous image formation (such as partially coherent imaging and vector diffraction theory) to develop a variety of important applications: point spread function (PSF) engineering, super-resolution imaging, quantitative phase imaging, adaptive optics, etc. It is also of our interest to apply computational approaches like deep learning to these applications. (* J. Kim et al., JOSAA 35, 526-535, 2018)
Optical system modeling & Vectorial field tracing/calculation* Optical system analysis: Theoretical PSF* & Transfer function Computational imaging: New methods or algorithms Quantitative phase imaging of semi-transparent objects (like cells)
Optical manipulation technology (광학 조작 기술)
Optical tweezers, a fascinating scientific concept to grab and manipulate microscopic objects like nano particles or cells (awarded the Nobel Prize in Physics 2018), have opened a new door to biophysics research. We are interested in advancing this manipulation technique in a new fashion, combined together with our rapid 3D imaging tool, to enable real-time 3D monitoring/control for broader applications including but not limited to cell mechanics, cell sorting, and optogenetics.
Biophotonic devices and systems (생체광학 소자 및 시스템)
Based on the previous research in lasers, plasmonics and metamaterials (see below), we are interested in devising new photonic devices/systems for biological, healthcare and industrial applications, with an emphasis on new cellular research, medical diagnostics and therapeutics and bio/chemical sensing.
Nanolaser systems: Design, fabrication, and characterization Perovskite nano laser device & Single photon emitter Plasmonics: Nano-focusing, optical resonance, etc. Metasurface: Light control via engineered nanostructure
References: Wong et al., Nature Photonics 10, 796-801 (2016); Xia et al., Nano Letters 19, 7100-7105 (2019); Shitrit et al., Physical Review Letters 121, 046101 (2018)