1995 Fiscal Year Final Research Report Summary

SECOND-ORDER OPTICAL NONLINEAR EFFECT IN GE-DOPED GLASS MATERIALS

Research Project

Project/Area Number	06650045
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	Applied optics/Quantum optical engineering
Research Institution	CHIBA UNIVERSITY,FACULTY OF ENGINEERING
Principal Investigator	OGURA Iwao CHIBA UNIVERSITY,FACULTY OF ENGINEERING,PROFESSOR, 工学部, 教授 (80013100)
Co-Investigator(Kenkyū-buntansha)	OMATSU Takashige CHIBA UNIVERSITY,FACULTY OF ENGINNERING,RESEARCH ASSOCIATE, 工学部, 助手 (30241938)
Project Period (FY)	1994 – 1995
Keywords	Second harmonic generation / Optical fiber / Photorefractive effects / Multi-photon absorption
Research Abstract	Theoretical investigation of a conversion efficiency of second harmonic generation in Ge-doped glass materials was carried out. Photo-carriors, generated by the multi-photon absorption during the seeding process, diffuse and produce a local electric field in glass materials. By the local electric field, the symmetry of glass materials is broken and the second order nonlinearity is induced. On the basis of this model, the second order nonlinear coefficient should be proportional to Iomega^4I_2omega^2 This scaling law agrees with the previous experimental results. Further, the build-up time of second order nonlinearity and the amplitude of local electric field depend on the excitation rate of photo-carriors. Doping impurities, which operate as a donor level, is effective for obtaining materials with larger nonlinearity.