Direct laser writing in glasses is a growing field of research in photonics since it provides a robust and efficient way to directly address 3D material structuring. Generally, direct laser writing in glasses induces physical modifications such as refractive index changes that have been classified under three different types (Type I, II & III). In a silver-containing zinc phosphate glass, direct laser writing additionally proceeds via the formation of silver clusters at the periphery of the interaction voxel. In this paper, we introduce a novel type of refractive index modification based on the creation of the photo-induced silver clusters allowing the inscription of a new type of optical waveguides. Various waveguides as well as a 50–50 beam splitter were written inside bulk glasses and characterized. The waveguiding properties observed in the bulk of such silver-containing glass samples were further transposed to ribbon shaped fibers made of the same material. Our results pave the way for the fabrication of 3D integrated circuits and fiber sensors with original fluorescent, nonlinear optical and plasmonic properties. The universality of these new findings should further extend in any silver-containing glasses that show similar laser-induced behavior in terms of silver cluster production.

International audienceTailored silver-containing zinc-phosphate glasses possess excellent thermoviscous ability and optical properties. Beyond they have proven to form a favorable matrix for the direct laser writing of photoluminescent and nonlinear patterns. Here, bringing together the merits of these materials with fiber optic technology, the first photosensitive, photowritable silver-containing glass ribbon fibers are reported. These novel devices are thermally scaled-down in a homothetic fashion from a macroscopic preform to produce tens-of-meters of continuous structure. It is demonstrated that luminescence properties of the native glass are preserved after the shaping process. Furthermore it is established that the unique fiber's flat geometry allows for the convenient, accurate laser writing of complex luminescent silver clusters patterns within the glass matrix. It is believed that the drawing of silver-containing zinc-phosphate glasses could lead to a decisive breakthrough in the field of photosensitive fibers. They would offer a promising platform for the design of highly efficient sensing devices based on amplified optical processes effects, for metamaterials or as fundamental bricks for photonics