Laser-induced glass processing has led to huge progress and applications over the last two decades. Here, we review recent advances in femtosecond laser-induced photochemistry in isotropic transparent oxide glasses specifically tailored with silver photoactive agents. The understanding of the influence of the considered glass matrix on the nature and properties of the created silver species is of prime importance. After presenting the key material properties, the formation mechanisms of laser-induced silver-based species are discussed, and potential technological applications are highlighted. Laser-induced processing of silver-containing oxide glasses paved the way for the fabrication of complex integrated waveguides and optical circuits with innovative fluorescent, nonlinear optical, and plasmonic properties. The universality of the method is expected to extend in any glass material that shows a similar laser-induced behavior in terms of silver cluster production.

Here we report on the production of crystal-free light guiding fibers using a preform-to-fiber approach in the germano-gallate glass system Ga₂O₃-GeO₂-BaO-La₂O₃-Y₂O₃ for various contents of gallium to germanium. For glasses in the system Ga₂O₃-GeO₂-BaO-K₂O, where surface crystallization precludes fiber drawing from the preform, an open-crucible technique enables the drawing of fiber samples tens of meters long. Cut-back optical attenuation measurements show the extended transmission in the mid-infrared of the produced fibers, up to 2.8 µm with minimum losses of 3.1 dB/m at 1310 nm from unpurified glass. These results show that the germano-gallate glasses represent promising mid-infrared materials over an extended fiber drawing domain.

The development of efficient and compact photonic systems in support of mid-infrared integrated optics is currently facing several challenges. To date, most mid-infrared glass-based devices are employing fluoride or chalcogenide glasses (FCGs). Although the commercialization of FCGs-based optical devices has rapidly grown during the last decade, their development is rather cumbersome due to either poor crystallization and hygroscopicity resilience or poor mechanical-thermal properties of the FCGs. To overcome these issues, the parallel development of heavy-metal oxide optical fiber from the barium-germanium-gallium oxide vitreous system (BGG) has revealed a promising alternative. However, over 30 years of fiber fabrication optimization, the final missing step of drawing BGG fibers with acceptable losses for meters-long active and passive optical devices had not yet been reached. In this article, we first identify the three most important factors that prevent the fabrication of low-loss BGG fibers i.e., surface quality, volumic striae and glass thermal-darkening. Each of the three factors is then addressed in setting up a protocol enabling the fabrication of low-loss optical fibers from gallium-rich BGG glass compositions. Accordingly, to the best of our knowledge, we report the lowest losses ever measured in a BGG glass fiber i.e., down to 200 dB km⁻¹ at 1350 nm.

Silver containing glasses in the P₂O₅ - Ga₂O₃ - Na₂O ternary diagram have been investigated to relate the effect of glass network structure and sodium ions concentration to spectroscopic and laser-writing properties of the materials. The first and most striking evidence is the large gain in the photosensitivity of fluorescent molecular silver clusters, and thus three-dimensional laser-induced patterns, from the meta-phosphate to the pyro-phosphate and ortho-phosphate glass compositions. This effect has been related to the progressive increase of the initial silver pairing quantity considering the shortening of the phosphate chains and the increase of the sodium ions concentration. One believes the presented detailed consideration of structure/property relationship will impact the design of new photosensitive glasses applied to the laser-manufacturing of components for photonic integrated circuits.

The ability to produce robust fiber-based integrated optical systems operating over a wide spectral domain (UV to mid-infrared), is one of today’s key challenges in photonics. This work reports on the production of crystal-free, light guiding fibers from rich Ga₂O₃ oxide-based glass compositions. These materials show optical transmission extending from ultraviolet wavelengths (∼0.280 µm) up to 6 µm in the IR for millimeter length scale while exhibiting relatively high vitreous transition temperatures (∼735 °C), nonlinear optical properties and improved surface micro-hardness. This combination of superior thermal, mechanical and optical properties represents a promising alternative for the development of robust fibers operating in the visible up to the 3–5 µm window.