This is the first report, to our knowledge, of refractive-index grating side writing in 10 mol.% GeO2-doped fiber by the near-UV light of a cw Ar+ laser (333–364 nm). An induced-index magnitude as large as 1.9 × 10-4 at 1.7×105 W/cm2 UV power density has been achieved. The observed gratings have exhibited the same temperature stability as gratings written by a KrF excimer laser (248 nm).
© 1997 Optical Society of America
E. M. Dianov, D. S. Stardubov, S. A. Vasiliev, A. A. Frolov, and O. I. Medvedkov, "Refractive-index gratings written by near-ultraviolet radiation," Opt. Lett. 22, 221-223 (1997)