Professor

• Ph.D. Physics-Fiber optics, Brown University, USA,  1994.

Thesis : "Spectroscopic studies of rare earth doped fibers and their applications in optical amplifiers, fiber lasers and gas  sensors" under the supervision of Prof. T. F. Morse, in Division of Engineering, Brown  University,

• M.S. Engineering, Brown University, USA, 1991.

• M.S. Physics-Solid state physics, Seoul National University, Korea, 1988.

• B.S. Physics, Seoul National University, Korea, 1986.

• 2025 ~ Present, Professor, Department of Physics, Nazarbayev University, Kazakhstan. 

• 2025 ~ Present, Professor Emeritus, Department of Physics, Yonsei University, Korea..

• 2018.9 ~ 2025.02, Director, Yonsei Physics Education and Research Institute, 

Yonsei University, Korea.

• 2009. 9 ~ 2025.8, Professor, Institute of Physics and Applied Physics, Department of Physics, Yonsei University, Korea.

• 2006. 9 ~ 2009. 8, Associate professor, Institute of Physics and Applied Physics, 

Department of Physics, Yonsei University, Korea.

• 2005.10 ~ 2006. 8, Professor, Department of Information and Communications, 

Gwangju Institute of Science and Technology, Korea.

• 2000.10 ~ 2005. 9, Associate  professor, Department of information and communications, 

Gwangju Institute of Science and Technology, Korea.

• 1996.3 ~ 2000. 9,  Assistant  professor, Department of information and communications, 

Gwangju Institute of Science and Technology, Korea.

• 2004. 6 ~ 2004. 9, 2004.12 ~ 2005. 2, Alexander von Humboldt Research Fellow, 

Helmholtz Institute for Physical High Technology, 

Fraunhofer Institute-IOF, Jena, Germany.

• 2004. 1 ~ 2004. 3, JSPS Invitation Fellow, Department of Electrical Engineering, 

The university of Tokyo, Japan.

• 2003. 7 ~ 2003. 8, Chevening Scholar, Optoelectronics Research Center (ORC), 

University of Southampton, UK.

• 2003. 1 ~ 2003. 2, Visiting Professor, National Chia Tung University, Hsinchu, 

Taiwan, Republic of China.

• 2002. 7 ~ 2002. 8, Visiting Scientist, Fiber Optic Material Research Program, 

Rutgers University, NJ, USA.

• 2000. 9 ~ 2002. 2, Visiting Scientist and Consultant, Optical Fiber Research Department, 

Bell Labs, Lucent Technologies,  Murray Hill, NJ, USA.

• 2001. 1 ~ 2003. 6, Consultant, Optical Components, Samyang Corporation, Korea.

• 1996 ~ 1998, Consultant, Specialty optical fiber, Samsung Electronics, Korea.

• 1998. 7 ~ 1998. 8, Visiting Assistant Professor of Research, Division of Engineering, 

Brown University, RI, USA.

• 1994.10 ~ 1996. 2, Senior researcher, Fiber and optical communication research center, 

LG Cable (a former joint venture of AT&T), Korea.

• 1994. 6 ~ 1994. 9, Post-doctoral research associate, Laboratory for lightwave technology, 

Brown University, USA.

• 1991. 6 ~ 1994. 5, Research assistant, Laboratory for Lightwave Technology, 

Brown University, USA.

• 1989. 9 ~ 1991. 5, Teaching Assistant, Physics Department, Brown University, USA.

• 1988. 8 ~ 1989. 2, Second Lieutenant, Korean Army, Korea.

• 1986. 3 ~ 1988. 2, Teaching Assistant, Department of Physics, Seoul National University, Korea.

• Executive Guest Editor, Results in Optics, Optical Biochemical Sensing and Imaging, Elsevier

• Specialty Chief Editor, Frontiers in Sensors, Frontiers

• Topical Editor, Optics Letters, Optica

• Associate Editor, IEEE Photonics Technology Letters, Optical Fiber Technology.

• Editorial Board Member, Optics Communications, Elsevier

• Executive Editor, Current Applied Physics, Elsevier.

• Editor in Chief, Journal of the Optical Society of Korea, Presently Current Optics and Photonics, Optical Society of Korea

  ■ Development of hollow optical fiber technology 

A unique design of a hollow fiber with a ring core has been proposed and experimentally demonstrated, for the first time, which could find various optical applications such as mode converters, dispersion compensators, tunable filters, and novel fiber lasers. Three invited talks have been given for HOF applications in international conferences, such as annual meetings of OSA, IEEE-LEOS, and OFS, Invited paper was published in OSA/IEEE Journal of Lightwave Technology, Feb. 2005. Patents filed.

  ■ Micro optical waveguide (MOW) on micro actuating platform (MAP) technology-

Novel tenability in micro optical waveguide systems has been realized, for the first time, in fiber couplers mounted on micro actuating platform. Utilizing acousto-optic, elasto-optic effects, versatile tuning mechanism has been invented to realized to result in flexible control of optical power splitting, wavelength selectivity, and polarization extinction. Invited paper was published in OSA/IEEE Journal of Lightwave Technology, Feb.2005. Patents filed.

 ■ All fiber laser beam shaping

Prior bulk optic technology for beam shaping has been successfully miniaturiezed in all-fiber platform. Bessel-like beams and Airy-like beams were generated using fiber optics showing non-diffractive nature and self-healing property. The all-fiber beam generators were immersed in a single droplet of water to trap and transport dielectric spheres and gold nano rods.

  ■ Waveguide based color image optical engine-

Full color synthesis was achieved using a multi-port fiber optic combiner and SMD type LEDs, for the first time. Red, green, and blue LEDs was efficiently coupled to hard plastic clad fiber coupler and the output covered the entire CIE 1931 Chromaticity diagram. Integrated optical engine in conjunction with MEMS ships could open a new avenue of imaging optical engine for micro-projection display.

  ■ Synthesis of radiative transition cross section of rare earth ions in novel optical waveguides-

Controllable and built-in filtering functions were demonstrated in Er doped fiber amplifiers, for the first time, by proposing a Sm doped inner cladding ring. The concept of evanescent wave interaction between the emission from the core and the absorption at the cladding ring could provide inherent methods to synthesize gain spectra, opening applications in gain flattening, gain shaping, for both optical amplifiers and lasers. The fiber laser project was funded by Asian Office of Aerospace Research and Development (AOARD), Air Force, USA, as a first Korean researcher. Patents filed.

 ■ Development of doping process for active fiber devices, and fiber laser sources

Various techniques have been developed in order to dope novel material for applications in nonlinear fiber devices. Development of long wavelength silica fiber laser based Er-Tm energy transfer was, for the first time, achieved opening applications in compact LIDAR and gas sensors. Er-Tm ASE source was developed for broadband applications. Athermal EDFA and high temperature operating fiber gratings have been invented using this technique. Two US patents have been filed along with collaborators in Bell Labs, Lucent Technologies.