How solids behave under extreme laser fields

Our efforts are directed towards fundamental understanding of intense laser matter interaction near material damage threshold. Although laser interaction with solids began with the advent of the laser 50+ years ago, many important aspects of the interaction, especially those that involve femtosecond (FS) lasers, are not clearly understood. Femtosecond laser interacts with matter differently than continuous wave (CW) lasers or pulsed nano-second (NS) lasers do. Intense CW and NS lasers in most cases, cause the interacting matter to heat up rapidly, melt and ablate. However, intense FS lasers cause the electrons in solid to rapidly ionize/transit to conduction band (dielectrics) and the electrons in the conduction band (metallic) are then accelerated by the laser field. These non-thermal distribution of electrons then causes rapid changes to the material surface before thermalization with lattice is achieved.

Many Applications required the use solids interacting with multiple femtosecond pulses at different repetition rates, between which the material may evolve for nano-seconds to micro-second time scales before the next pulse comes in. Understanding these phenomena require probing the evolution of interaction from femtosecond to microsecond time scale, over nine orders of magnitude in time!

This laboratory is supported by