Photosensitivity and Treatments for Enhancing the Photosensitivity of Silica-Based Glasses and Fibers

VUV and IR absorption spectra induced in H2-loaded and UV hyper-sensitized standard germanosilicate preform plates through exposure to ArF laser light

“…The first one is the GeODC (II) defect reaction with hydrogen under UV absorption leading to a hydrogen containing species like H-bearing species. Then, under two-photon absorption [26], these species transform into GeE 0 releasing hydrogen. This part of the mechanism leads to several features: a dramatic increase in the GeE 0 concentration and thus a dramatic increase in the refractive index at the beginning of the exposure.…”

“…Starting from a comprehensive survey of the literature, we have suggested in Refs. [26,27] a mechanism that is summarized by the following equations: The first mechanism (at the top of the group) is composed by two successive reactions. The first one is the GeODC (II) defect reaction with hydrogen under UV absorption leading to a hydrogen containing species like H-bearing species.…”

Reliable Lifetime Prediction for Passivated Fiber Bragg Gratings for Telecommunication Applications

“…To this purpose, the fibers were exposed through a phase mask (Lasiris; pitch = 1057 nm; diffraction power efficiency in the −1, +1 and 0 orders = 34%, 34% and 1% respectively) to a cw laser emitting at 244 nm. All the exposures were carried out at a mean power density ≈35 W/cm 2 . In this paper we will investigate two series of FBG.…”

“…They are usually reflectivity and sometimes Bragg wavelength and Bragg bandwidth. The relation between these quantities and the refractive index changes (noted RIC below) along the grating are explained in Reference [2,3]. Let us recall only the important features.…”

“…We have also to remark that beyond the assumption of a limiting reaction, Δn(z, t w , T w ) arises from several physical phenomena directly proportional to each other's [2,3]: creation of species with a polarizability different from the non-irradiated matter polarizability, some re-organization of the matter (e.g., glass density changes) and stress redistribution. All these phenomena can thus be reduced to only one species that we will call B in such a way that the question of stability of the RIC restricts only to the stability of B.…”