Laser Induced Shock Waves and Vaporization in Biological System and Material Science
Abstract
Theoretical and computational work was carried out to investigate the underlying physical mechanisms that cause laser induced biological damage and material stress. In order to cause damage to the absorbing material, the electromagnetic energy of the laser pulse must be converted to thermo-mechanical energy. We have developed a computational model that allows the calculation of damage resulting from a laser pulse of any duration or energy due to temperature rise, explosive bubble formation, and shock wave production. We have discovered that the system exhibits chaotic dynamics. We have shown quantitatively that the chaos inherent in the system leads to the surprising result that small changes in laser parameters, such as duration or energy, can produce large changes in the thermo-mechanical response of the system. This causes certain laser pulse durations and energies to be especially difficult to protect against, whereas other laser regimes are especially safe. We also discovered resonant effects in laser absorption and damage that allow the duration between pulses to be tuned to channel a greater or lesser fraction of the absorbed energy into shockfront and bubble production. This allows the delivery of large amounts of laser energy to produce strong thermal effects while suppressing unwanted pressure effects, or vice versa.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 30, 2008
- Accession Number
- ADA476965
Entities
People
- Bernard S. Gerstman
Organizations
- Florida International University