Role of CaO addition in the local order around Erbium in SiO2 ?GeO2 ?P2O5 fiber preforms

TL;DR

This study investigates how adding CaO to Er-doped SiO2–GeO2–P2O5 fiber preforms alters the local environment of Erbium ions, affecting optical properties relevant for signal processing.

Contribution

It provides new insights into the impact of CaO on the local structure around Erbium in fiber preforms using photoluminescence and EXAFS analysis.

Findings

CaO modifies the local environment of Erbium ions.

The emission line width correlates with local structural order.

Amorphous or crystalline local structures influence optical properties.

Abstract

The development of materials for optical signal processing represents a major issue in present technology. In this contribution we present a study on Er-doped fiber preforms where particular attention is devoted on how the addition of CaO in the glass modifies the local environment of the rare earth. The results from photoluminescence and Extended X-ray Absorption Fine Structure (EXAFS) are compared and a clear link between the width of the emission line at 1.5 $\mu$m and the amorphous/crystalline local structure around the Er3+ ion is evidenced.