Figure 1

(a) The photographs of scanned fields showing the surface morphology for different pulse spacing at wavelength and laser fluence: 1030 nm and F = 4.4 J/cm2; 515 nm and F = 8.0 J/cm2; 343 nm and F = 4.9 J/cm2; (b) optical microscope images of the top and rear surfaces of the samples irradiated with pulse spacing 30 μm, scale bar is common for all images in Fig. 1b.