| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2004: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2003: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2002: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Research Abstract |
Effect of thermal poling conditions on second harmonic generation in fused quartz was studied. The roles of minority species such as oxygen point defects, Na^+ and H^+ were considered and the thickness of second-order nonlinear active layer, dc current during poling process, microstructure using transmission electron microscopy were evaluated. Glass forming region, physical properties and structure of vitreous RS-Ga_2S_3 (R=Ca,Sr,Ba) were studied as a new sulfide glass system. Effects of GeS_2 and B_2O_3 additions on the thermal properties and structure of BaS-Ga_2S_3-GeS_2 and BaO-P_2O_5-B_2O_3 glass systems were also studied, respectively. New glass compositions which can draw into fiber forms without crystallization were found in these systems for fiber optics. Microlens formation, as induced by single shot of a femtosecond laser pulse, was observed in Sm-doped non-crystalline SrS-Ga_2S_3 thin films. The metallic- to semiconductor-phase transition was induced in metallic SmS thin films by a generatively amplified mode-locked Ti : sapphire laser. From the point of Ag photo-doping behavior, Ge-S,Ge-Sb-S and Ga_2S_3 sulfide glasses can be classified into 2 groups : (1)covalent glasses containing S-S bonds and point defects (e.g., S-rich Ge-S and Ge-Sb-S glasses) and (2)ionic glasses containing modifier ions such as Ge^<2+>,Ba^<2+> and La^<3+> (e.g., Ge_<40>S_<60> and Ga_2S_3 glasses). The former glasses only show Ag photo-doping and are appropriate for structural modification by light for planar waveguide and photonic crystal formations. The latter glasses with relatively-good stability against laser irradiation may be suitable for relatively-high power applications as IR fiber lasers and amplifiers.
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