Pulsed laser energy deposition (LED) uses a laser to cause an optical breakdown in a target material, which becomes plasma and is deposited as a thin film on a substrate. By carefully tuning the properties of the laser and the target material, it is possible to precisely control the resulting plasma plume. Most commonly, a single short laser pulse is used to create this effect. However, it is also possible to produce a plasma plume by firing two laser pulses at the same area.

Singh et al. examined a double-pulse LED (DP-LED) both experimentally and numerically and provided an explanation of the produced effects as well as an analysis of how best to employ these effects for practical use.

“This study provides an insight into the evolution of laser-induced plasma during single- and successive-laser energy deposition and suggests the configurations where DP-LED can be acceptable for practical use,” said author Awanish Pratap Singh.

The team found using a double pulse LED over a single pulse gives more control over the energy and lifetime of the plasma. By varying the pulse interval, the duration of the plasma plumes can be precisely controlled.

The team analyzed the behavior of the double-pulse system in the context of Maxwell’s theory of momentum exchange between light and matter. Using this framework, they were able to explain the existence of a fourth, backward-facing plasma lobe and observed shock waves produced in the target material.

The researchers hope their study provides a framework that will help others working with pulsed laser deposition.

Source: “Insight into the evolution of laser-induced plasma during successive deposition of laser energy,” by Awanish Pratap Singh, Upasana Priyadarshani Padhi, and Ratan Joarder, Journal of Applied Physics (2022). The article can be accessed at https://doi.org/10.1063/5.0080306.