Holographic capture of femtosecond pulse propagation

Authors

Martin Centurion, University of Nebraska - LincolnFollow
Ye Pu, California Institute of TechnologyFollow
Demetri Psaltis, California Institute of Technology

Document Type

Article

Date of this Version

9-2006

Comments

Published in JOURNAL OF APPLIED PHYSICS 100, 063104 (2006); DOI: 10.1063/1.2345469 © 2006 American Institute of Physics. used by permission

Abstract

We have implemented a holographic system to study the propagation of femtosecond laser pulses with high temporal (150 fs) and spatial resolutions (4 μm). The phase information in the holograms allows us to reconstruct both positive and negative index changes due to the Kerr nonlinearity (positive) and plasma formation (negative), and to reconstruct three-dimensional structure. Dramatic differences were observed in the interaction of focused femtosecond pulses with air, water, and carbon disulfide. The air becomes ionized in the focal region, while in water long plasma filaments appear before the light reaches a tight focus. In contrast, in carbon disulfide the optical beam breaks up into multiple filaments but no plasma is measured. We explain these different propagation regimes in terms of the different nonlinear material properties.