Direct laser writing on fluorophosphate glasses codoped with rare-earth and silver for the production of non-linear optical devices

• Grant number: 21/14705-2
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: February 01, 2022
• End date: June 30, 2025
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Hellmut Eckert
• Grantee: Vinicius Duarte Jesus
• Host Institution: Instituto de Física de São Carlos (IFSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated research grant: 13/07793-6 - CEPIV - Center for Teaching, Research and Innovation in Glass, AP.CEPID
• Associated scholarship(s): 22/11274-3 - Laser inscription of high optical contrast in photosensitive oxyfluoride glasses: investigation of silver and fluorine co-mobility & application to large refractive index changes, BE.EP.DR

Abstract

The project aims to prepare and characterize glasses of mixed fluorophosphate systems based on gallium phosphate, with alkali and alkaline earth metal fluorides (MF and MF2), codoped with silver and rare-earth ions to obtain luminescent nanoclusters of silver distributed through the glass matrix through thermal treatment of the samples and also through the laser photostructuring process, and study of the possible energy transfer for rare-earth ions. The glasses will be prepared using the thermal shock-fusion technique. The addition of silver in the composition will be made gradually until the stability limit, where it is possible to maintain a homogeneity and transparency of the sample. After having different samples with vitreous compositions that meet these requirements, the glasses will be annealed, polished and subjected to thermal characterization via thermal analysis of Differential Scanning Calorimetry (DSC), to obtain the characteristic temperatures of the material; structural characterizations of X-Ray Diffractometry (XRD), Scanning Electron Microscopy (SEM) and FT-IR and Raman Spectroscopy, in order to assess the details of the atomic arrangement of each of the compositions. From the structural knowledge of the studied glasses, the samples will be submitted to optical characterizations of UV-Vis-NIR and Luminescence Spectroscopy. After these characterizations, the growth of silver nanoclusters in the glass matrix will be performed, through heat treatments at temperatures lower than the glass transition (Tg) or by Direct Writing by Femtosecond Laser (DLW), to evaluate the effects of structural change with formation of these clusters in the response of optical and transfer properties between silver nanoclusters and rare-earth ions.