Nd:YAG laser induced E' centers probed by in situ absorption measurements

TL;DR

This study examines how pulsed Nd:YAG laser irradiation affects E' centers in natural and synthetic silica, revealing that natural samples develop transient E' centers influenced by hydrogen reactions, while synthetic samples resist such effects.

Contribution

It provides in situ measurements of laser-induced E' centers in silica, highlighting the role of hydrogen in their kinetics and differences between natural and synthetic materials.

Findings

Laser-induced absorption occurs only in natural silica.

Synthetic silica shows high resistance to laser irradiation.

E' center kinetics are affected by hydrogen diffusion and reactions.

Abstract

We investigated various types of commercial silica irradiated with a pulsed Nd:YAG laser radiation (4.66 eV), with exposure time ranging up to 10000 s. Transient E' centers were probed in situ by measuring the amplitude of the optical absorption band at 5.8 eV (due to E' centers) both during and after irradiation. The laser-induced absorption is observed only in natural samples, whereas the synthetic materials exhibit high toughness to radiation effect. The reported results evidence that the kinetics of E' centers is influenced by their reaction with diffusing molecular hydrogen H2 made available by dimerization of radiolytic H0.