Laser-Induced Point Defects in Fused Silica Irradiated by UV Laser in Vacuum

Xiaoyan Zhou,Xiaodong Jiang,Xinda Zhou,Jin Huang,Fengrui Wang,Xin Ye,Weidong Wu,Qiang Cheng

doi:10.1155/2014/853764

Xiaoyan Zhou, Xiaodong Jiang + Show 6 more

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https://doi.org/10.1155/2014/853764

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Abstract

High-purity fused silica irradiated by third harmonic of the Nd:YAG laser in vacuum with different laser pulse parameters was studied experimentally. Laser-induced defects are investigated by UV spectroscopy, and fluorescence spectra and correlated to the structural modifications in the glass matrix through Raman spectroscopy. Results show that, for laser fluence below laser-induced damage threshold (LIDT), the absorbance and intensity of fluorescence bands increase with laser energies and/or number of laser pulses, which indicates that laser-induced defects are enhanced by laser energies and/or number of laser pulses in vacuum. The optical properties of these point defects were discussed in detail.

Highlights

Fused silica has excellent ultraviolet (UV, λ ≦ 400 nm) transparency, optical homogeneity, and high antidamage performance in UV pulse laser [1, 2]
We attempted to characterize the point defects in fused silica induced by low fluence laser (355 nm Nd:YAG laser pulses) with different laser pulse parameters in vacuum
Compared with the damage threshold of fused silica optics measured in vacuum and air, laser-induced damage threshold of fused silica was slightly decreased in vacuum, which implies that vacuum can degrade the damage performance of fused silica

Summary

Introduction

Fused silica has excellent ultraviolet (UV, λ ≦ 400 nm) transparency, optical homogeneity, and high antidamage performance in UV pulse laser [1, 2]. This optical property allows this material to be used in optical materials for large high power output systems such as Laser Megajoule and National Ignition Facility [3, 4]. We attempted to characterize the point defects in fused silica induced by low fluence laser (355 nm Nd:YAG laser pulses) with different laser pulse parameters in vacuum. The formations of point defects before and during the laser-induced material damage were discussed in detail

Experiment Procedures

Results and Discussion

Conclusion