Sulfophosphate Glass Doped with Er3+ and TiO2 Nanoparticles: Thermo-Optical Characterization by Photothermal Spectroscopy

Zeinab Ebrahimpour,Humberto Cabrera,Joseph Niemela,Asghar Asgari,Fahimeh Ahmadi

doi:10.3390/photonics8040115

Abstract

In this work, time-resolved thermal lens and beam deflection methods were applied to determine the thermo-optical properties of Er3+ doped sulfophosphate glass in which different concentrations of Titanium dioxide (TiO2) nanoparticles (NPs) were embedded. Thermal diffusivity (D), thermal conductivity (κ), and the temperature coefficient of the optical path length (ds/dT) were determined as a function of NPs concentrations. Moreover, the growth of TiO2 NPs inside the amorphous glass matrix was evidenced by Transmission Electron Microscopy (TEM) images as well as through optical effects such as refractive index change of the glass. The outcomes indicated relatively high values for D and κ as well as a low ds/dT as required for most optical components used for laser media. The addition of TiO2 NPs with concentration of dopants up to 0.6 mol% improved the optical properties of the glass samples but did not affect its thermal properties. The results indicate that the enhanced optical and thermal performance of the proposed co-doped glass fits the quality standards for materials used in photonic devices.

Highlights

Transmission Electron Microscopy (TEM) imaging was used to confirm the presence of the TiO2 NPs doped in the glass matrix
The results demonstrate that the introduction of TiO2 NPs causes an increase in the temperature of Tg, Tc, and Tm
TiO2 NPs were inserted in the Er3+ doped sulfophosphate glass matrix and their presence was investigated by TEM and demonstrated by the changes of the optical band gap and refractive index of the glass samples

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Phosphate based glasses doped with Lanthanide ions (Ln3+ ) have attracted great interest due to their thermo-optical properties and applicability in the development of photonics devices. These luminescent materials have been used for active media of solidstate lasers, LEDs, solar cells, and other photonics devices [1,2,3,4]. Erbium ion (Er3+ )-doped glasses have been investigated for a wide range of applications including infrared and green solid-state lasers, broadband optical sources, and optical amplifiers [5,6]

Methods

Results

Conclusion