An optical corrosion sensor employs an optical fiber Bragg grating 20 embedded
within an optical fiber 18. The grating 20 has a coating 40 made
of a material, such as aluminum, which corrodes or can otherwise be removed. The
coating 40 exerts forces 46 radially inward around and along the
grating 20 so as to cause the wavelength bandwidth of the grating reflectivity
profile to become broader and to be shifted relative to its uncoated condition.
Also, the forces on the grating 20 are reduced when the coating corrodes,
thereby causing the wavelength bandwidth and shift of the reflectivity profile
of the grating to narrow and to return to its uncoated condition.
