Photography by Gabiele Photography
Laser ablation
Laser Induced Plasmas (LIP) are produced when a high power pulse laser beam is focused onto a solid target, vaporizing some material; this process is known as ablation. In addition, a LIP can be produced in gasses or liquids as long as this media are transparent to the laser wavelength. Some applications of LIP are listed below:
- Pulsed Laser Deposition, PLD. This is a method to produce thin films coatings on a substrate from ablated particles of the target. The coating is performed in a vacuum chamber, and if suitable ablation conditions were met, the thin film would have the same composition as the target. PLD can also be implemented within a reactive atmosphere, so the resulting coating was a composite material, e.g. oxides or nitrides. Usually, the maximum surface to be homogeneously deposited is around 1 cm2.
- Laser Induced Breakdown Spectroscopy, LIBS. This process is typically performed at atmospheric pressure. Since the produced plasma mostly contains target material, its elemental composition can be determined via plasma emission spectroscopy. Main advantages of this characterization are that it requires a practically null sample preparation and can be portable.
- Surface cleaning. Since laser ablation produces minimal surface damage, it can be used to gradually remove superficial layers that could contaminated because of exposure to the surrounding ambient. Removal control is performed via emission spectroscopy and this procedure might be useful to clean delicate samples such as art work or archeological pieces.