Bragg gratings have been written in an optical fiber with a core made from ternary SiO<sub>2</sub>: SnO<sub>2</sub>: Na<sub>2</sub>O glass and a SiO<sub>2</sub> cladding. The presence of Na<sub>2</sub>O allows for higher concentrations of SnO><sub>2</sub> , which are believed to be responsible for the photorefractive response of this composition. In these preliminary experiments significant refractive-index modulations, up to 6.2×10<sup>-4</sup> , have been achieved with a 248-nm excimer laser and a phase mask to write gratings for reflectivity at ~1.5µm . The induced refractive-index changes show enhanced temperature stability, and there is no sign of any erasure up to temperatures exceeding 600 °C.
© 2000 Optical Society of America
G. Brambilla, V. Pruneri, L. Reekie, C. Contardi, D. Milanese, and M. Ferraris, "Bragg gratings in ternary SiO2:SnO2:Na2O optical glass fibers," Opt. Lett. 25, 1153-1155 (2000)