to the edges of one coverslip. Next, 2 μL of the aforementioned colloidal aqueous solution was placed in the center of the coverslip. Finally, another coverslip was placed on top of the first one, creating a sample chamber with a thin water film sandwiched between the two coverslips. If the application of vacuum grease was insufficient, the colloidal solution may occasionally leak slightly from the chamber. To eliminate the impact of this minor leakage, the sample chamber was left to stand for at least 24 hours to ensure there was no reduction in the solution volume before being used for laser irradiation experiments. The thickness of the water layer was approximately 8 μm.