UV-Photoinduced Defects In Ge-Doped Optical Fibers

TL;DR

This study explores how continuous UV laser exposure causes defects in germanium-doped optical fibers, identifying specific defect types responsible for increased optical absorption using innovative measurement techniques.

Contribution

It introduces a new method to measure UV-induced optical absorption and identifies Ge(1) defects as key contributors to this process in Ge-doped fibers.

Findings

UV irradiation induces measurable optical absorption in Ge-doped fibers.

Ge(1) defects are identified as primary responsible for UV-induced absorption.

A novel measurement technique was developed for defect analysis.

Abstract

We investigated the effect of continuous-wave (cw) UV laser radiation on single-mode Ge-doped H2- loaded optical fibers. An innovative technique was developed to measure the optical absorption (OA) induced in the samples by irradiation, and to study its dependence from laser fluence. The combined use of the electron spin resonance (ESR) technique allowed the structural identification of several radiation-induced point defects, among which the Ge(1) (GeO4 -) is found to be responsible of induced OA in the investigated spectral region.