Research / Materials Science / Ultrafast Laser Ablation

 

A 120-femtosecond laser pulse (near-infrared, not visible) is focused onto a Titanium target to an intensity of 1016 W/cm2.  The laser pulse ionizes the material immediately into a solid-density plasma.  The plasma expands away from the target (long after the laser pulse is over).  The atomized & ionized material is collected on a substrate to grow a thin film.

The plasma plume is in the center of the blue glow shown above.  Surrounding the plasma plume is ionized nitrogen which emits blue light.  This ablation was done in a chamber filled with nitrogen gas.  The electrons from the plasma plume are accelerated by a discharge ring set at 1000 V and ionize the nitrogen gas through collisions.  An activated background gas like this is used to enhance thin film growth of particular materials, either to incorporate additional elements into the film or to neutralize the vaporized material.

Research / Materials Science / Ultrafast Laser Ablation