Hyoun Soo Kim

Pohang University of Science and Technology, Antō, North Gyeongsang, South Korea

Are you Hyoun Soo Kim?

Claim your profile

Publications (8)6.27 Total impact

  • Se Ho Park · Dong Chin Lee · Jong Heo · Hyoun Soo Kim
    [Show abstract] [Hide abstract]
    ABSTRACT: Fluorescence emissions at both 1.31 and 1.55 μm communication windows were observed from Pr3+/Er3+ codoped Ge-As-Ga-S glasses with a single wavelength pumping at 986 nm. The lifetime of the Er3+:4I11/2 level decreased as the Pr3+ concentration increased, and that of the Pr3+:1G4 level increased as the Er3+ concentration increased. Energy transfer from the Er3+:4I11/2 level to the Pr3+:1G4 level was responsible for emission of the 1.31 μm fluorescence from the Pr3+:1G4 level. Ge-As-Ga-S glasses that have been doped with Pr3+ and Er3+ cations are promising amplifier materials for both 1.31 and 1.55 μm communication windows.
    Journal of the American Ceramic Society 12/2004; 83(5):1284 - 1286. DOI:10.1111/j.1151-2916.2000.tb01370.x · 2.61 Impact Factor
  • Yong Beom Shin · Jong Heo · Hyoun Soo Kim
    [Show abstract] [Hide abstract]
    ABSTRACT: Alkali halides such as KBr, KI, CsBr, and CsI were added to Dy3+-doped Ge–Ga–S glasses, and their effects on the 1.31-μm emission property were investigated. The intensities of the 1.31-μm emission (6F11/2 · 6H9/2 → 6H15/2) increased at the expense of the 1.75-μm emission intensity (6H11/2 → 6H15/2) with the alkali halide addition. The lifetimes of the 1.31-μm emission level also increased as much as 35 times from 38 μs for Ge–Ga–S glass to 1320 μs for the glass containing 10 mol% CsBr. These enhancements occurred only when the ratio of MX (M = K, Cs; X = Br, I)/Ga was equal to or larger than unity. Raman spectra of Ge–Ga–S–CsBr glasses indicated the formation of [GaS3/2Br]− complexes, which provide the preferred sites for Dy3+. Due to this new local environment of Dy3+, the multiphonon relaxation rates from the Dy3+:6F11/2 · 6H9/2 level decreased by approximately four orders of magnitude. The enhancement in the 1.31-μm emission properties with alkali halide addition supports the potentials of these glasses as hosts for the Dy3+-doped fiber-optic amplifiers.
    04/2001; 16(05):1318 - 1324. DOI:10.1557/JMR.2001.0184
  • Source
    Yong Beom Shin · Jong Heo · Hyoun Soo Kim
    [Show abstract] [Hide abstract]
    ABSTRACT: The effect of changes in the local phonon modes and electron–phonon coupling strengths on the 1.31 μm fluorescence efficiency of Dy3+-doped sulfide glass was investigated. An addition of 10 mole% CsBr resulted in a sharp increase in the 1.31 μm emission intensity at the expense of the 1.75 μm emission. The lifetime of the 1.31 μm emission level (–) increased to 1.58 ms, which was more than 40 times larger than that of the Ge–Ga–S host. Quantum efficiency increased from 17% to approximately 100%. These changes in the optical characteristics resulted from the large changes in the local phonon modes and electron-coupling strengths through the addition of CsBr to Ge25Ga10S65 glass.
    Chemical Physics Letters 02/2000; 317(6-317):637-641. DOI:10.1016/S0009-2614(99)01400-1 · 1.90 Impact Factor
  • Jong Heo · Hye Sun Lee · Pong Je Park · Yong Beom Shin · Hyoun Soo Kim
    [Show abstract] [Hide abstract]
    ABSTRACT: Emission properties of 1.3 μm fluorescence from Pr<sup>3+</sup> or Dy<sup>3+</sup> were investigated using host glasses with ultra-low phonon energy. Highly efficient 1.3 μm amplifier materials can be realized from selenide and GeGaS-CsBr glasses
    Optical Fiber Communication Conference, 2000; 02/2000
  • Se Ho Park · Jong Heo · Hyoun Soo Kim
    [Show abstract] [Hide abstract]
    ABSTRACT: Effects of concentration on the amplification efficiency at 1.3 mu m were investigated in Ge-Ga-S glass doped with 100-5000 ppm (in wt.) Pr3+. Quantum efficiencies and figure-of-merits (sigma(g)tau(m)) increased from 49%, 26.3 +/- 0.5 x 10(-25) cm(2) s to 66%, 31.1 +/- 0.5 x 10(-25) cm(2) s, respectively, with sulfur concentration decreasing from 69 to 63 at.%. Optimum compositions of the host glasses are Ge32Ga5S63 and Ge28Ga20S62 (at.%). Concentration of Pr3+ must be <500 ppm in weight to minimize detrimental cross relaxation, which is the major energy transfer process in glasses. A linear dependence of the reduced diffusion coefficients indicated an inhomogeneous distribution of Pr3+ in glasses.
    Journal of Non-Crystalline Solids 11/1999; 259(1):31-38. DOI:10.1016/S0022-3093(99)00492-5 · 1.77 Impact Factor
  • Jong Heo · Yong Beom Shin · Hyoun Soo Kim
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper reports the enhanced lifetime and quantum efficiency of 1.3 μm emission from Dy<sup>3+</sup>. Addition of CsBr into Ge-Ga-S glasses showed lifetime increase of more than 50 times compared to Ge-Ga-S glasses. Quantum efficiency increased to 100%
    Lasers and Electro-Optics, 1999. CLEO/Pacific Rim '99. The Pacific Rim Conference on; 02/1999
  • Jong Heo · Yong Beom Shin · Hyoun Soo Kim
    [Show abstract] [Hide abstract]
    ABSTRACT: The addition of CsBr and KBr in Ge-Ga-S glasses doped with Dy<sup>3+</sup> showed a remarkable increase in the 1.32 μm emission intensity. Lifetimes and quantum efficiency also increased to 700 μs and 100%, respectively compared to 38 μs and 17% usually found in Ce-Ga-S glasses
    Optical Fiber Communication Conference, 1999, and the International Conference on Integrated Optics and Optical Fiber Communication. OFC/IOOC '99. Technical Digest; 02/1999
  • Jong Heo · Se Ho Park · Dong Chin Lee · Hyoun Soo Kim
    [Show abstract] [Hide abstract]
    ABSTRACT: We report on the possibility of a fiber amplifier at 1.3 and 1.55 μm dual wavelength using the Pr3+ and Er3+ co-doped sulfide glasses. In fact, the energy transfer phenomenon in the Er3+ and Pr3+ co-doping system has been previously researched in order to achieve a cw-laser at 2.7μm. Then, we also investigate for the additive enhancement of the 1.3 μm amplifying efficiency due to the dopant energy transfer