1997 Fiscal Year Final Research Report Summary
The optical properties and local structure of trace elements in glasses
| Project/Area Number |
07405056
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Metal making engineering
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
MORINAGA Kenji Kyushu University Department of Materials Science and Technology Graduate School of Engineering Sciences Professor, 大学院・総合理工学研究科, 教授 (70038074)
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| Project Period (FY) |
1995 – 1997
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| Keywords | glass / photonic glass / rare earthe ion / transition metal ion / spontaneous emission probability / redox / solid state laser material / matrix effect |
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| Research Abstract |
Rare earth and transition metal ions as a trace element are very important roles in a solid state laser materials. The optical properties and valency state of trace element depend on the glass composition as laser matrix. In this research, the compositional dependence of optical properties of trace element doped glasses were investigated. We selected the optimum glass composition for the laser materials.
1. We calculated the spontaneous emission probabilities of the particular transitions of rare earth ions in silicate, borate, and phosphate glasses on the basis of the Judd-Ofelt theory.
(1) The results reveal that the transitions ^3F_<3/2>*^4I_<11/2> of Nd^<3+>, ^6F_<11/2> * ^6H_<15/2> of Dy^<3+>, ^4S_<3/2> * ^4I_<15/2> of Er^<3+>, and ^2F_<5/2> * ^2F_<7/2> of Yb^<3+> in oxide glasses show possibility for the solid state laser materials.
(2) The matrix effect of K_2O-Ga_2O_3-Ta_2O_5 glass provides the high spontaneous emission probabilities of the transition, which are affected by the <||U^<(2)>||>^2, for Dy^<3+> and Yb^<3+> ions.
2. The compositional dependences of the valency state of Cu and Cr ions in oxide glasses were inverstigated.
(1) We concluded optimum glass composition for Cu^+ doped tunable glass laser materials is 10Na_2O・80B_2O_3・10Al_2O_3 because Cu^+ ion was chemically stabilized by matrix effect of alumina.
(2) We concluded glass systems suitable for Cr^<4+> doped tunable glass laser materials is Al_2O_3 and Ga_2O_3 based glasses because the superoxide ion radical (O_2^-) and the peroxy bonding (-0-0) oxidize Cr^<3+> to Cr^<4+> in the aluminate and gallate glasses.
3. We concluded glass composition suitable for Ce^<3+> doped glass laser materials for short wavelength light source is AlF_3 based glasses with high transmission in ultraviolet region.
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