1994 Fiscal Year Final Research Report Summary
Fundamental studies on the laser diode pumped solid-state laser driver
| Project/Area Number |
05680431
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Nuclear fusion studies
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| Research Institution | Osaka University |
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Principal Investigator |
YAMANAKA Masanobu Osaka University, Institute of Laser Engineering, Associate Professor, レーザー核融合研究センター, 助教授 (10029118)
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| Project Period (FY) |
1993 – 1994
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| Keywords | Laser fusion / Laser diode / LD pumped solid-state laser / Solid-state laser / Driver / Fusion Reactor / Yb : glass / Nd : glass |
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| Research Abstract |
Technical and economical feasibility of a laser diode (LD) pumped solid-state laser driver for the fusion reactor is examined, Nd-doped solid-state laser materials with lasing wavelength at 1mum are serected. Using a conceptual designing technique, a prototype-model driver is designed, which has the specifications for a reactor driver such as an output energy of 4MJ per pulse at the wavelegth of 0.35mum, overall efficiency of 12% and a repetition rate of 12Hz.
According to a small scale experiment of an LD pumped Nd : YAG laser system, it is shown that the Lowdermilk and Murray theory can be used as a guide line when a high-energy high-efficiency laser driver.
An efficient LD array surface pumped Nd : YAG disk amplifier with an optical-optical conversion efficiency of 12% is demonstrated. Tow -dimensional thermal stress-induced birefingence in the disk amplifier is successfully measured using a newly designed polarimeter. An energy extraction efficiency of 65% is obtained which is well fitted to the Frantz-Nodvik equations taking into account of the thermal birefringent loss.
To measure the fluorescence lifetime of Yb lasant, a widely tunable (750-1040nm) all-solid-state KTP parametric converter featuring low pump energy threshold (0.4mJ for the 532nm, 8ns, 50Hz input) and high conversion efficiency (27%) is realized.
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