Figure 7.

Illustration of the laser ablation of metals in liquids at different fluences varied by the pulse energy (a) and the working distance (b). The diagram in (c) demonstrates how the fluence variation caused by different initial spot sizes affects the NP productivity in LAL in the high-fluence regime. A Gaussian beam profile was assumed. In (c), both axes scale linearly. The trends shown in the diagram represent the interpretation of the combined results of the discussed literature in Section 2.2.1. The arrow and the less dense (dashed) line style in (c) indicate the trend in productivity induced by a smaller initial spot size. Reprinted with permission from [66].