Ya-Ming Dong

Publications (2)0 Total impact

• Article: Relationship between composition, density and refractive index for heavy metal fluoride glasses

  S. F. Shaukat, Ya-ming Dong, R. Farooq, P. R. Hobson
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  ABSTRACT: The density and the refractive index for various compositions of heavy metal fluoride (HMF) glasses, used to make low-loss optical wave-guides, have been measured by standard archimedes method and by using as Pulfrich refractometer respectively. The density as a function of composition is calculated considering the effective volume of the ions contained in the glass to be invariant. The refractive index as a function of composition is also calculated, based on the Lorenz-Lorentz equation, by computing the electronic polarizability of HMF glasses. All calculated results are in good agreement with the observed data.
  Journal of Shanghai University (English Edition) 04/2012; 5(3):201-204.
• Article: Sensitized up-conversion luminescence of Ho3+ in Nd3+-Yb3+-Ho3+ co-doped ZrF4-based glass

  S. F. Shaukat, Ya-Ming Dong, M. Hussain, R. Farooq, Guang-Yuan Li
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  ABSTRACT: Up-conversion processes for the blue, green and red emissions were found two-photon phenomenon, known as the cooperative phenomenon. This phenomenon was assisted by Nd3+ → Yb3+ → Ho3+ energy transfer. The strong green emission due to the Ho3+ : (5F4, 5S2)→ 5I8 transitions was observed in Nd3+-Ho3+ co-doped ZrF4-based fluoride glasses under 800 nm excitation. As an attempt to enhance Ho3+ up-conversion luminescences in the Nd3+ – Ho3+ co-doped ZrF4-based glasses, Yb3+ ions were added to the glasses. As a result it was found that, in 800 nm excitation of 60 ZrF4. 30BaF2. (8-x)LaF3. lNdF3. xYbF3. 1HoF3 glasses (x=0 to 7), sensitized up-conversion luminescences are observed at around 490 nm (blue), 545 nm (green), and 650 nm (red), which correspond to the Ho3+ : 5F3 → 5I8, ( 5F4, 5S2)→5I8 and 5F5→ 5I8 transitions respectively. The intensities of the green and red emissions in a 3 mol % YbF3-containing glass were about 50 times stronger than those glasses without YbF3. This is based on sensitization due to Yb3+ ions. In particular, the green emission was extremely strong and the Nd3+-Yb3+-Ho3+ co-doped ZrF4-based glasses have a high possibility of realizing a green up-conversion laser glass. In this paper the up-conversion mechanism in the glasses is discussed in detail.
  Journal of Shanghai University (English Edition) 02/2002; 6(1):45-49.