Fabrication of long-period optical fiber gratings by use of ion implantation

We report the fabrication of long-period optical fiber gratings by use of a refractive-index increase induced by ion implantation. Helium ions were implanted in an optical fiber core through a metal mask that had a 170-mu m-pitch grating with spacing of 60 mu m. We obtained a wavelength-dependent effective transmission loss by use of the grating. (C) 2000 Optical Society of America. OCIS codes: 060.0060, 220.4000, 230.1480, 160.6030, 230.0230, 350.2770.