Technical Note: Nanoparticle Generation With Femtosecond Pulsed Laser Deposition

By IMRA America, Inc.

Pulsed laser deposition (PLD) has been proven as a relatively easy way to produce thin film coatings and specialized finishes on metal and dielectric substrates. Research facilities, and now some commercial coating companies, have employed nanosecond lasers to achieve results that were not easily and reproducibly available using other technologies. Pulsed laser deposition is a subset of the broader laser material processing marketplace which has been increasing its impact in industrial applications over the past two decades.

Excimer lasers and Q-switched solid-state lasers are widely used in PLD systems, with pulse duration in the nanosecond range. In the last several years however, femtosecond lasers have shown great promise to improve the quality and reduce the scale of fine detail which can be obtained by laser micromachining. The unique ablation properties of femtosecond lasers that render higher precision in micromachining with reduced thermal effects, as well as a reduction in debris, recast, and burring, can also be beneficial to PLD, depositing materials onto a substrate with improved quality and better controllability. This opens up possibilities to either replace conventional lasers in some applications. Moreover, a variety of new emerging applications can be enabled by these unique capabilities. Typically, PLD is used to produce thin films, but it has also been applied to the creation of nanoparticles (particles on the nanometer scale).

Deposition technology is used in the semiconductor and flat panel display industries, along with being used for MEMS, nanotechnology, and optics. PLD with ultrashort pulses has been demonstrated using various ultrafast lasers. In this note, generation and deposition of uniform nanoparticles via femtosecond laser ablation will be described.