Large SHG in UV-Poled Silica Glass

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].