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Related Experiment Video

Updated: Jun 25, 2026

Characterization of Surface Modifications by White Light Interferometry: Applications in Ion Sputtering, Laser Ablation, and Tribology Experiments

Characterization of Surface Modifications by White Light Interferometry: Applications in Ion Sputtering, Laser Ablation, and Tribology Experiments

Published on: February 27, 2013

Field dependent avalanche ionization rates in dielectrics.

P P Rajeev¹, M Gertsvolf, P B Corkum

¹National Research Council of Canada, Ottawa, Canada, K1A 0R6.

Physical Review Letters

|March 5, 2009

Summary

Field-assisted collisional ionization is a cold avalanche mechanism in multiphoton ionization. This process occurs even with ultrashort laser pulses, challenging traditional avalanche theories.

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Characterization of Surface Modifications by White Light Interferometry: Applications in Ion Sputtering, Laser Ablation, and Tribology Experiments

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Published on: February 27, 2013

Using Laser Scanning Microscopy to Determine Electromigration in Molybdenum Disilicide

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Published on: May 23, 2025

Area of Science:

Optics and Photonics
Materials Science
Plasma Physics

Background:

Multiphoton ionization is crucial for understanding laser-matter interactions.
Avalanche ionization typically requires longer laser pulse durations.
The role of ionization mechanisms in fused silica under intense ultrashort laser pulses is not fully understood.

Purpose of the Study:

To investigate the ionization mechanisms in fused silica induced by intense ultrashort laser pulses.
To elucidate the contribution of field-assisted collisional ionization to multiphoton ionization.
To explore the dependence of laser absorption on pulse duration.

Main Methods:

Analyzing the absorption of intense ultrashort laser pulses focused inside fused silica.
Varying the laser pulse length to study its effect on absorption.
Correlating absorption data with ionization mechanisms.

Main Results:

Absorption of intense ultrashort laser pulses in fused silica is dependent on pulse length.
Field-assisted collisional ionization plays a significant role in the multiphoton ionization process.
A cold avalanche ionization mechanism was identified, active at pulse lengths previously considered too short for traditional avalanche.

Conclusions:

Field-assisted collisional ionization provides a viable mechanism for laser energy absorption in fused silica with ultrashort pulses.
This finding extends the understanding of avalanche ionization to shorter pulse durations.
The study reveals a novel cold avalanche ionization pathway relevant to laser-induced damage and material processing.