Kinetics of Blue Emission during Ultraviolet Insolation on Germanosilicate Optical Fiber

The research aimed to study the kinetics of 400 nm blue emission during ultraviolet insolation on germanoslicate optical fiber, hydrogenated, and non-hydrogenataed. The hydrogenation of the fibers was carried out at room temperature under 150 atm for 4 weeks. The focused frequency doubled Argon laser ultraviolet beams were directed to the core of the unsheathed fiber. The light beams emerging from the end of the fiber were directed towards a detector. Kinetics the creation of defects in the hydrogenated fiber followed the power law for low fluency insolation. At high fluency, the formation of defects followed the principle of two photosensitization or serial steps

Hydroxyl Properties of Hydrogenated Germanosilicate Optical Fiber Due to Thermal Treatment and Ultraviolet Irradiation

The aim of the research was to examine the formation and destruction of the hydroxyl in optical fibers by comparing the ambient atmosphere, air, and nitrogen during thermal treatment from room temperature up to 1100 °C. It has been shown that during the heat treatment, molecular hydrogen dissolved in the fiber plays no role in the formation of OH while under UV irradiation the formation is dependent on the presence of dissolved hydrogen. The heat treatment preferentially leads to the formation of Si-OH, while during irradiation it assists the formation of both Ge-OH and Si-OH

Silver Nanoparticles Formation By Redox Reaction In Laser Treated Sodalime Glass

International audienceWe report on the formation of silver nanoparticles by intense ultraviolet laser exposure of silver-exchanged sodalime glass. The laser exposure leads to the formation of a molten glass phase in which a redox reaction occursbetween diffused oxygen form the atmosphere and the silver ions. The mechanism responsible for their formation is rather counterintuitive as oxygen acts as a very efficient reducer of the silver ions

Ultraviolet-induced absorption during very short continuous exposure in Ge-doped optical fiber

International audienceWe report an experimental study on the photoinduced optical absorption (OA) changes in Ge-doped optical fibers, in the 360- 435 nm spectral range. An original set up was used allowing very short continuous (cw) exposure (6-30 ms), where the intrinsic 400 nm photoluminescence (PL), assigned to the two-fold coordinated Ge, is used as probe source. We investigated, in both unloaded and H2-loaded fibers, the dependence of this photoinduced OA on the fluence, in the 0.1-4.8 J/cm2 range. Four kinds of uncoated optical fibers with different Ge content, 0, 4, 13, 17 mol%, were transversally exposed to a cw frequency-doubled Ar+ laser operating at 244 nm. Increasing the fluence up to ~0.6 J/cm2, on both unloaded and H2-loaded fibers, the photoinduced OA increases and reaches a maximum. For larger fluences, the photoinduced OA decreases monotonically in the unloaded fibers whereas it remains constant in the H2-loaded ones. This OA decreases monotonically when the wavelength increases, indicating that it is the low energy tail of an absorption band located at larger energies. These photoinduced OA increase on increasing the Ge content. Based on our experimental results and on the literature data, we propose that the Ge(1) formation, via a consecutive two-step process, may be the source for the measured photoinduced OA

Etude des processus photochimiques primaires dans les fibres optiques germanosilicates lors d'une insolation ultraviolette

International audienceNous reportons des mesures d'absorption induite, dans le domaine spectral 360 nm-440 nm, dans les fibres germanosilicates hydrogénées ou non. Pour cela, nous avons mis au point une nouvelle technique de mesure de l'absorption induite mettant en évidence, contrairement à la technique de mesure classique, les processus primaires générés durant des temps d'insolation ultraviolette (uv) très courts (~ms). Nos observations montrent que le centre Ge(1) est responsable de cette absorption dans les deux types de fibres

Ultraviolet-induced absorption during very short continuous exposure in Ge-doped optical fiber

Abstract We report an experimental study on the photoinduced optical absorption (OA) changes in Ge-doped optical fibers, in the 360-435 nm spectral range. An original set up was used allowing very short continuous (cw) exposure (6-30 ms), where the intrinsic 400 nm photoluminescence (PL), assigned to the two-fold coordinated Ge, is used as probe source. We investigated, in both unloaded and H 2 -loaded fibers, the dependence of this photoinduced OA on the fluence, in the 0.1-4.8 J/cm 2 range. Four kinds of uncoated optical fibers with different Ge content, 0, 4, 13, 17 mol%, were transversally exposed to a cw frequency-doubled Ar + laser operating at 244 nm. Increasing the fluence up to $0.6 J/cm 2 , on both unloaded and H 2 -loaded fibers, the photoinduced OA increases and reaches a maximum. For larger fluences, the photoinduced OA decreases monotonically in the unloaded fibers whereas it remains constant in the H 2 -loaded ones. This OA decreases monotonically when the wavelength increases, indicating that it is the low energy tail of an absorption band located at larger energies. These photoinduced OA increase on increasing the Ge content. Based on our experimental results and on the literature data, we propose that the Ge(1) formation, via a consecutive two-step process, may be the source for the measured photoinduced OA

Crystallisation effects on rare earth dopants in oxyfluoride glass ceramics

Transparent oxyfluoride glass-ceramic materials are of significant interest for the production of new optoelectronic devices. In this paper we report measurements of the detailed spectroscopy of rare earth dopants in both an oxyfluoride transparent glass ceramic and its glass precursor. We show that several spectroscopically different sites exist for the rare earth even in the glass precursor material, where a significant amount of the rare earth is already coordinated with fluorine. In the glass-ceramic material, these glassy fluorine-coordinated sites are replaced with crystalline sites, but a significant fraction of the rare earth ions are still within the glass phase. The fraction of rare earth ion that is incorporated into the crystalline phase is estimated from the rare earth spectroscopy, and the role of the rare earth coordination in the precursor glass is discussed

Site-selective spectroscopy in dysprosium-doped chalcogenide glasses for 1.3µm optical fiber amplifiers

Dy3+ -doped chalcogenide glasses are potential candidates for 1.3µm optical-fiber amplifiers. We describe spectroscopic characterization of Dy3+ -doped gallium lanthanum sulphide glasses with low and high oxide content. The spectroscopic investigations show that small amounts of oxide (1) in low-oxide-content sulphide glass create a second group of sites with a local environment different than that of the main sulphide sites. Dy3+ ions in the oxide site, which can constitute up to approximately one third of the total number of Dy3+ ions, experience a high-phonon-energy environment and do not show any 1.3µm emission and hence cannot provide gain for a potential 1.3µm optical-fiber amplifier in this material

Étude des processus photochimiques primaires dans les fibres optiques germanosilicates lors d'une insolation ultraviolette

Nous reportons des mesures d'absorption induite, dans le domaine spectral 360 nm-440 nm, dans les fibres germanosilicates hydrogénées ou non. Pour cela, nous avons mis au point une nouvelle technique de mesure de l'absorption induite mettant en évidence, contrairement à la technique de mesure classique, les processus primaires générés durant des temps d'insolation ultraviolette (uv) très courts ($\sim$ms). Nos observations montrent que le centre Ge(1) est responsable de cette absorption dans les deux types de fibres

UV assisted local crystallization in Er3+ doped oxy-fluoride glass

International audienceWe report the precipitation of Er3+-doped nanoparticles inside transparent glasses by use of an original technique,combining heat treatment below glass crystallization temperature (TC) to UV laser exposure. This allows to control the spatial localization of the nanoparticles in the glass sample, whereas annealing solely at TC leads to a fully crystallized glass sample. The photoluminescence properties of Er 3+ ions in the glass and crystal are used to follow the structural changes in the glass network under heat treatment and UV exposure