Growth of lithium tetraborate with periodic twin structure formed by applying an electric current during growth for the use of deep-ultraviolet light laser

2014 Fiscal Year Final Research Report

• Project/Area Number: 25600083
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Crystal engineering
• Research Institution: Tohoku University
• Principal Investigator: UDA Satoshi 東北大学, 金属材料研究所, 教授 (90361170)
• Co-Investigator(Renkei-kenkyūsha): SHOJI Ichiro 中央大学, 理工学部, 教授 (90272385) ; NOZAWA Jun 東北大学, 金属材料研究所, 助教 (60569317) ; KENSAKU Maeda 東北大学, 大学院工学研究科, 助教 (40634564)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: 四ホウ酸リチウム / 双晶 / 周期双晶構造 / 擬似位相整合構造 / 深紫外光

Outline of Final Research Achievements

We have succeeded in the growth of lithium tetraborate with periodic twin structure forming during growth by applying an electric field or manipulating a growth orientation relative to the twin boundary. Since lithium tetraborate is not ferroelectric, the conventional method for the formation of the quasi-phase matching structure (QPM) is not possible. By revealing the formation mechanism of (100) and (010) twins, we managed alternative twin formation with these orientations, which made the periodic twin structure with small period. This structure can be served as a QPM structure and the secondary harmonic generation of Nd:YAG laser was successfully obtained. It is a remarkable result that the QPM formation is possible for non-ferroelectric material.

Free Research Field

結晶成長