Control of ionization processes in high band gap materials via tailored femtosecond pulses

Control of two basic ionization processes in dielectrics i.e. photo ionization and electron-electron impact ionization on intrinsic time and intensity scales is investigated experimentally and theoretically. Temporally asymmetric femtosecond pulses of identical fluence, spectrum and pulse duration r...

Full description

Saved in:
Bibliographic Details
Published in:Optics express 2007-12, Vol.15 (26), p.17855-17862
Main Authors: Englert, L, Rethfeld, B, Haag, L, Wollenhaupt, M, Sarpe-Tudoran, C, Baumert, T
Format: Article
Language:English
Subjects:
Aluminum Oxide - chemistry
Aluminum Oxide - radiation effects
Ions
Lasers
Manufactured Materials
Materials Testing
Semiconductors
Silicon Dioxide - chemistry
Silicon Dioxide - radiation effects
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Control of two basic ionization processes in dielectrics i.e. photo ionization and electron-electron impact ionization on intrinsic time and intensity scales is investigated experimentally and theoretically. Temporally asymmetric femtosecond pulses of identical fluence, spectrum and pulse duration result in different final free electron densities. We found that an asymmetric pulse and its time reversed counterpart address two ionization processes in a different fashion. This results in the observation of different thresholds for surface material modification in sapphire and fused silica. We conclude that control of ionization processes with tailored femtosecond pulses is suitable for robust manipulation of breakdown and thus control of the initial steps of laser processing of high band gap materials.
ISSN:1094-4087
1094-4087
DOI:10.1364/oe.15.017855