The origin of frequency doubling in Ge-doped silica-core single-mode glass fibers has been investigated with electron-spin-resonance spectrometry. Correlations have been observed between the conversion efficiency and the light-induced Ge E′ center concentration.
© 1989 Optical Society of America
T. E. Tsai, M. A. Saifi, E. J. Friebele, D. L. Griscom, and U. Österberg, "Correlation of defect centers with second-harmonic generation in Ge-doped and Ge-P-doped silica-core single-mode fibers," Opt. Lett. 14, 1023-1025 (1989)