Abstract: Hydrogen-induced losses in germanium-doped fibers is significantly reduced by increasing the concentration of oxygen in the core region of the glass. The increase in oxygen functions to “heal” the germanium-deficient defects, thus substantially reducing the sites where hydrogen bonding can intrude. Advantageously, the presence of the excess oxygen does not compromise the ability to create UV-induced gratings in the fiber's core area. Indeed, the stability of the glass has been found to increase even further during UV radiation. Thus, an FBG structure suitable for use in harsh, high temperature environments can be formed.

Abstract: An optical fiber resistant to hydrogen-induced attenuation losses at both relatively low and relatively high temperatures includes a substantially pure silica core and a hydrogen retarding layer. The hydrogen retarding coating may be made of carbon, metal, or silicon nitride. The fiber may also include a cladding layer, a second silica layer, and a protective outer sheath.

Abstract: An optical fiber resistant to hydrogen-induced attenuation losses at both relatively low and relatively high temperatures includes a substantially pure silica core and a hydrogen retarding layer. The hydrogen retarding coating may be made of carbon, metal, or silicon nitride. The fiber may also include a cladding layer, a second silica layer, and a protective outer sheath.