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- 5th 'Art in Science' Prize Winner

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Galaxy in fish eye 

by Jin Hee Hong, Yonghyeon Jo, Jaecheol Jo

- Prof. Wonshik Choi received a grand scholarship award from the Optical Society of Korea (Feb. 20, 2020)

- Our work, "Deep tissue space-gated microscopy via acousto-optic interaction," is published at Nature Communications

- Prof. Wonshik Choi became the Fellow of the Optical Society of America

- Our work entitled "Label-free neuroimaging in vivo using synchronous angular scanning microscopy with single-scattering accumulation algorithm" was published in Nature Communications on July 17, 2019

Abstract: Label-free in vivo imaging is crucial for elucidating the underlying mechanisms of many important biological systems in their most native states. However, the applicability of existing modalities has been limited to either superficial layers or early developmental stages due to tissue turbidity. Here, we report a synchronous angular scanning microscope for the rapid interferometric recording of the time-gated reflection matrix, which is a unique matrix characterizing full light-specimen interaction. By applying single scattering accumulation algorithm to the recorded matrix, we removed both high-order sample-induced aberrations and multiple scattering noise with the effective aberration correction speed of 10,000 modes/s. We demonstrated in vivo imaging of whole neural network throughout the hind- brain of the larval zebrafish at a matured stage where physical dissection used to be required for conventional imaging. Our method will expand the scope of applications for optical imaging, where fully non-invasive interrogation of living specimens is critical.

- Our work on 'focusing light energy to an embedded target in scattering media' was published at Nature Photonics on March 27, 2018

Title: Focusing of light energy inside a scattering medium by controlling the time-gated multiple light scattering
Abstract: The efficient delivery of light energy is a prerequisite for the non-invasive imaging and stimulating of target objects embedded deep within a scattering medium. However, the injected waves experience random diffusion by multiple light scattering, and only a small fraction reaches the target object. Here, we present a method to counteract wave diffusion and to focus multiple-scattered waves at the deeply embedded target. To realize this, we experimentally inject light into the reflection eigenchannels of a specific flight time to preferably enhance the intensity of those multiple-scattered waves that have interacted with the target object. For targets that are too deep to be visible by optical imaging, we demonstrate a more than tenfold enhancement in light energy delivery in comparison with ordinary wave diffusion cases. This work will lay a foundation to enhance the working depth of imaging, sensing and light stimulation.
See article at https://www.nature.com/articles/s41566-018-0120-9

Featured at IBS Research highlight

This work was introduced at a few local media including the one below.

- Our paper for deep-tissue adaptive optical imaging was published at Nature Communications (Dec 18, 2017)

Title: High-resolution adaptive optical imaging within thick scattering media using closed-loop accumulation of single scattering (Nature Communications 8, 2157 (2017))

Abstract: Thick biological tissues give rise to not only the multiple scattering of incoming light waves, but also the aberrations of remaining signal waves. The challenge for existing optical microscopy methods to overcome both problems simultaneously has limited sub-micron spatial resolution imaging to shallow depths. Here we present an optical coherence imaging method that can identify aberrations of waves incident to and reflected from the samples separately, and eliminate such aberrations even in the presence of multiple light scattering. The proposed method records the time-gated complex-field maps of backscattered waves over various illumination channels, and performs a closed-loop optimization of signal waves for both forward and phase-conjugation processes. We demonstrated the enhancement of the Strehl ratio by more than 500 times, an order of magnitude or more improvement over conventional adaptive optics, and achieved a spatial resolution of 600 nm up to an imaging depth of seven scattering mean free paths.

See the article at https://www.nature.com/articles/s41467-017-02117-8

This work was introduced at a few local newspapers. Here is one of them.

Implementation of plasmonic MIMO network published at Nature Communications

See the article at http://www.nature.com/articles/ncomms14636

- Yonghyeon got a best paper award, JOSK

- Prof. Wonshik Choi became Associate Director for IBS CMSD

- CASS microscopy published at Nature Photonics

See the article at http://www.nature.com/nphoton/journal/v9/n4/full/nphoton.2015.24.html

- Lensless single-fiber endoscope published in PRL

See the article at http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.109.203901
The work was also introduced at Research Highlights in  Nature

- First experimental realization of transmission eigenchannels published at Nature Photonics

See the article at http://www.nature.com/nphoton/journal/v6/n9/abs/nphoton.2012.159.html