정영주(Youngjoo Chung)

Education

  • 1989 Princeton University (Ph.D.- Plasma Physics)
  • 1985 Princeton University (M.A.- Plasma Physics)
  • 1982 Seoul National Univ (B.S – Physics)

Professors

  • 2001-Present GIST Professor
  • 1996 – 2001 GIST Associate Professor.
  • 1989 – 1996 Advanced Photon Source, Argonne National Laboratory.

Research Interest

  • Fiber Bragg gratings and long-period fiber gratings
  • Optical fiber devices and components
  • Optical signal processing
  • Optical communication and sensing
  • Development of computational tools in above areas

Lab Introduction

  • Optical Fiber Device LaboratoryThe Optical Fiber Device Laboratory at Gwangju Institute of Science and Technology is doing research optical fiber-based devices, components and systems. Current main research is focused on fabrication and device application of optical fiber Bragg gratings and long-period fiber gratings for communication and sensing. For this purpose, attempts are being made to improve existing techniques and to develop novel schemes for grating fabrication. Research on application of specialty fiber-based devices to WDM communication systems such as wavelength converters and multiwavelength fiber lasers are actively pursued. Application of fiber gratings to optical fiber sensors is also being studied. Theoretical works for development of both analytical and numerical computation tools are also being conducted for design of optical fiber Bragg gratings and grating-based devices.Fabrication of the Optical Fiber Bragg GratingsThe existing fabrication schemes for optical fiber Bragg gratings are roughly categorized into: 1) single-beam internal method, 2) dual-beam holographic method, 3) phase-mask photolithographic method, and 4) point-by-point fabrication method. Implementation of these various fabrication techniques is investigated at the same time as exploration of novel fabrication schemes.

    Wavelength Converters

    Wavelength conversion using cross-gain modulation (XGM) and cross-phase modulation (XPM) in erbium-doped fiber is being studied. Unlike the conventional method employing semiconductor optical amplifiers (SOAs), the EDF-based wavelength converter has the potential for high signal-to-noise ratio and cost effectiveness.

    Multiwavelength Lasers

    We are conducting fabrication and characterization of a multiwavelength fiber laser for DWDM applications using cascaded long-period fiber gratings (LPFGs) as the multichannel filter. The characteristics of the laser are primarily determined by the LPFGs, and research is being conducted for more lasing wavelengths and denser channel spacing.

    Development of Applications of the Fiber Bragg Grating

    For realization of the applications and devices with the desired characteristics using optical fiber Bragg gratings, research is being conducted on development of the optical fiber devices, e.g., dispersion compensator, reflection-type filter, optical resonator cavity, and measurement of the characteristics data.

    Device Simulation Tools for Linear and Nonlinear Cases

    To design and optimize various types of the optical fiber devices, development of simulation tools in the linear and nonlinear regimes is being undertaken. Using these simulation tools, optimum waveguide and fiber grating structure parameters that determine properties of the optical fiber and fiber-based devices can be determined.

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