Strong photosensitivity of antimony oxide doped fibers under irradiation at 193Â nm

Single-mode Sb-doped fibers with ∼1.0 mol.% Sb2O5 in the core have been fabricated by the MCVD method. Photosensitivity of pristine, pre-exposed, and H2-loaded Sb-doped fibers under exposure at 193 nm has been measured and compared for the first time. Strong photosensitivity in pristine Sb-fibers has been discovered. The pre-exposure phenomenon has been found in Sb-doped fibers. However, it is weaker than in Ge and P-doped fibers. Growth of induced index and induced losses in Sb-fibers can be explained by a two-step photochemical reaction occurring in the fiber core. Modification of some different defects is proposed to occur in H2-loaded Sb-doped fiber under exposure.