Abstract

A number of work have been reported on enhancement of the second-order nonlinearity in silica-related glasses, e.g. poling at elevated temperatures (200~500 °C) in bulk fused-silica [1], in sol-gel films [2], and in those of waveguide- and fiber forms, in addition [3,4]. Recently, a significant increase of the effective electro-optic (EO) coefficient in a germanosilicate fiber was reported [5], where UV irradiation was applied along with an intense electric poling field. The EO coefficient measured in the fiber poled in that way was comparable to r₂₂ in LiNbO₃. This “UV-poling" method has a further advantage of spatial resolution, which is useful to create periodically poled structures for the quasi phase-matching SHG and the EO-tunable Bragg gratings [6].

© 1997 Optical Society of America