Transmission of Intense Femtosecond Laser Pulses into Dielectrics
Abstract
The interaction of intense, femtosecond (fsec) laser pulses with a dielectric medium is examined using a numerical simulation. The simulation uses the 1-D electromagnetic wave equation to model laser pulse propagation. In addition, it includes multiphoton ionization, electron attachment, ohmic heating of free electrons, and temperature dependent collisional ionization. Laser pulses considered in this study are characterized by peak intensities 10(exp 12) to 10(exp 14) W/sq cm and pulse durations ^10 to 100 fsec. These laser pulses, interacting with fused silica, are shown to produce above-critical plasma densities and electron energy densities sufficient to attain experimentally measured damage thresholds. Significant transmission of laser energy is observed even in cases where the peak plasma density is above the critical density for reflection. A damage fluence based on absorbed laser energy is calculated for various pulse durations. The calculated damage fluence is found to be consistent with recent experimental results.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 26, 2005
- Accession Number
- ADA437902
Entities
People
- A. Zigler
- Bahman Hafizi
- J. R. Penano
- Phillip A. Sprangle
- Wallace M. Manheimer
Organizations
- United States Naval Research Laboratory