2002 Fiscal Year Final Research Report Summary
High performance widely tunable chromachip lasers
| Project/Area Number |
12792003
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| Research Category |
Grant-in-Aid for University and Society Collaboration
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| Allocation Type | Single-year Grants |
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| Research Field |
Applied optics/Quantum optical engineering
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| Research Institution | Okazaki National Research Institutes |
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Principal Investigator |
TAIRA Takunori Institute for Molecular Science, Associate Professor, 分子科学研究所, 助教授 (50216595)
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| Co-Investigator(Kenkyū-buntansha) |
KURIMURA Sunao National Institute for Materials Science, 主任研究員
IKESUE Akio Japan Fine Ceramics Center, 主任研究員
SHOJI Ichiro , 助手 (90272385)
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| Project Period (FY) |
2000 – 2002
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| Keywords | Diode pumped solid-state lasers / Ceramic lasers / Chromachip lasers / Boundary controlling / Nd : YAG / Thermal birefringence / Quasi phase matching / MgO : LiNbO_3 |
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| Research Abstract |
As part of the "High performance widely tunable chromachip lasers" research project we have investigated new types of solid-state microchip lasers and nonlinear wavelength conversion by the Quasi-Phase-Matching process as follows :
(1) We have demonstrated highly efficient laser oscillation using highly concentrated Nd-doped YAG ceramics by grain boundary controlling. The spectrum bandwidth was controlled by changing the composition structure : Nd : YSAG ceramics that have Al sights partially replaced by Sc has 5 times wider the gain band width compared with Nd : YAG.
(2) A new model that describes theoretically the thermal birefringence in high power state lasers by changing the orientation of crystal axis from <111> to <110> or <100>-axis cut without any other internal optics into the optical resonator was developed. Moreover, a new pumping method that reduces the heat generation was proposed and experimentally proved.
Directly pumping into the emitting level of Nd : YAG lasers improves
… More
the quantum defect but the absorption efficiency is poor for low concentrated Nd : YAG (1.0-at.% Nd, usually used in construction of lasers). We demonstrated that highly Nd-doped YAG ceramics has the potential to overcome this disadvantage, assuring high absorption efficiency for this new pumping scheme. Finally, simulation source code by FEM that estimate the heat generation and its thermal problem was developed.
(3) We have developed an 'in-situ' poling system that optimizes the QPM fabrication process of MgO : LiNbO_3 that is characterized by a high damage threshold. Then we have realized a periodically poled 3-mm thick MgO : LiNbO_3. Moreover, we found the way for broadening the acceptance bandwidth by using d_31 (= d_32) instead of the normal d_33 coefficient.
(4) During this research project were published 25 scientific papers and 6 review papers, 33 presentations were given at international meetings and 24 at domestic meetings, as well as 12 invited talks. Finally, we have received 4 awards. Less
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