Researcher of the Ceramics and Glass Institute (CSIC, Spain). Main research topics are glasses and glass-ceramics for sealing, transparent glass-ceramics for photonic applications, phase separation and crystallization in glasses, sintering/crystallization, and glass recycling.
Co-author of more than 130 articles in SCI journals (h-index 38). Principal researcher of two European projects. Member of the technical committee TC07 “Nucleation, Crystallisation and Glass-ceramics” of the International Commission on Glass (ICG) from 2007 and its current vice-chair. Secretary and vice-president of the Glass Section of the Spanish Society of Ceramics and Glass (SECV). ICG Gottardi prize 2010. Treasurer and member of the Management Board and Steering Committee of the ICG (2015-2024). Chair of Crystallization 2017 in Segovia (Spain).

Alternative processing and enhanced properties of photonic glass-ceramics

The growing field of photonics demands the design of new rare-earth (RE)-based optical materials for their use in efficient optical telecommunications, solid-state lasers and other applications. Oxyfluoride glass-ceramics (GCs) combine the transparency and both mechanical and chemical resistance of aluminosilicate glasses with the low phonon energy and facile incorporation of RE ions in the fluoride crystals. The incorporation of RE ions in the crystalline phases (such as LaF3) enhances the optical emission intensity. Moreover, the additional presence of metallic nanoparticles such as Ag can further enhance the luminescent response. These materials are suitable for the preparation of preforms as precursors for the drawing of optical fibers and as substrates for waveguides written using laser radiation and some examples of the materials preparation and its possible applications will be provided.
By the other hand, transparent GC materials have also been obtained by spark plasma sintering (SPS). This approach combines thermal action with simultaneous compression of the material to reach full densification and high homogeneity in a short time. The structural, mechanical, and optical properties have been characterized and compared with GCs of the same compositions prepared by conventional heat treatment. 
This work was supported by MICINN under Project PID2020-115419GB-C-21/C-22/AEI/10.13039/501100011033.