STUDY OF THE PHOTOSENSITIVITY AT 193 NM AND COMPARISON WITH PHOTOSENSITIVITY AT 240 NM INFLUENCE OF FIBER TENSION - TYPE IIA AGING

The photosensitivity in germanosilicate fibers at 193 nm is studied an d compared with that at 240 mm, As previously shown, it is found that, without hydrogen sensitization, the initiation of the phenomenon is a one-photon process for a high germanium content fiber and a two-photo n process for a low germanium content fiber, However, when the low ger manium content fiber is previously loaded with hydrogen, it is observe d that the photo-induced index change initial growth rate varies linea rly with the fluence, invoking a one-photon process, It is shown that external strains applied to the fiber strongly influence the mechanism s of the photosensitivity at 193 mn, Finally, an aging study is carrie d out.