A regenerated optical waveguide is fabricated by hydrogenating an optical waveguide
(12) and exposing a grating section (28) to a UV laser beam interference
fringe pattern (14) to form a Type I grating. The grating section (28)
is exposed for a second period to erase the Type I grating, and then a third period
to cause a regenerated optical waveguide grating to form. The resonant wavelength
increases during the third period from being substantially the same as the final
wavelength of the Type I grating.
