Luminescent glasses, optical fibers and composites for optical sensing and photonic applications

Author(s)

Renato Grigolon Capelo

• Document type: Doctoral Thesis
• Press: São Carlos.
• Institution: Universidade de São Paulo (USP). Instituto de Química de São Carlos (IQSC/BT)
• Defense date: 2024-12-17

Examining board members

Juliana Mara Pinto de Almeida; Maggy Dutreilh Colas; Danilo Manzani; Younes Messaddeq; Frédéric Smektala

• Advisor: Danilo Manzani

Abstract

This work explores the design, synthesis, and application of luminescent glassy materials and composites for optical sensing and photonic technologies. The research focuses on developing novel optically active materials using oxide glass matrices suitable for fiber drawing, such as tellurite and phosphate glasses, which are modified to improve their optical and thermal properties. The introduction of network modifiers, particularly fluorides, results in glass systems with increased transparency and appropriate chemical stability. These matrices were doped with rare-earth ions (RE3+) and nanoparticles, and they also served as substrates for the growth of luminescent coordination polymers (Ln-CPs), enabling the production of new glass@Ln-CP composites with significant potential for chemical sensing. A systematic approach was employed to characterize these glass matrices using techniques such as X-ray diffraction (XRD), Raman spectroscopy, solid-state nuclear magnetic resonance (NMR), and absorption spectroscopy, providing insights into their structural, optical, and thermal properties. The synthesis of optically active phosphate glasses co-doped with RE3+ demonstrated the capability to promote upconversion (UC) luminescence, highlighting their potential for photonic applications. The research also emphasizes the development of glass@Ln-CP composites, synthesized through in situ growth on glass substrates and optical fibers. These composites exhibit strong luminescent responses to carbonyl compounds like acetone and 2-pentanone, demonstrating their potential for chemical sensing. Furthermore, coated optical fibers enable the transmission of luminescent signals over long distances, facilitating real-time and remote detection of analytes. Thus, this thesis contributes to the development of new luminescent materials and fiber-optic-based sensors, offering a versatile platform for innovative optical sensors and photonic devices. (AU)

• FAPESP's process: 20/12280-1 - Waveguides based on oxide glasses of heavy atoms for optical sensing of gases in the UV-Vis range
• Grantee: Renato Grigolon Capelo
• Support Opportunities: Scholarships in Brazil - Doctorate