If the surface of a sample is irradiated by such interference field with well defined spatial Adjacent to 
energy distribution, a corresponding topography or Nano-microstructure will be produced, figure 2, ar 
through different mechanisms, mentioned above, depending on the laser wavelength, energy intensity ha 
density and also the physical and chemical parameters of the materials. features wit 
temperature 
Using three 
Figure 4 an 
3. Results i The 
Using second, third and fourth harmonic oscillations from Nd:YAG laser with different 
wavelengths and under different geometrical configurations, microstructures on surfaces of 
Semiconductor, metal, ceramic and polymer are produced; the form, the size of the feature, 
and topography are characterised by White Light Interference microscope(WLI) and atom 
force microscope AFM). 
3.1 Various topographies and microstructures © 
Figure 2 and 3 are the nano-microstructures on the surface of c-Si made by two-beam 
interference from second harmonic, 532 nm Nd:YAG laser. The surface profile show Figure 4. « 
clearly a linear structure, feature size of 25 nm depth with lateral period of 19 pm and beam inter 
4 pm of width. An interesting point is that the shape of the form of each individual 
feature is not sinusoidal. the structur 
Qualitative 
above the 1 
energy den 
controlling 
Similar str 
interferenc: 
FF 
Figure 6 N 
WLI and ( 
. . . . The sampl 
Figure 2 WLI image of linear structure on the Figure 3 AFM image of linear structure on the thickness 
surface of c-Si made by 532 nm Nd:YAG surface of c-Si made by 532 nm Nd:YAG beam inte: 
laser laser um, as she 
and depth 
pattern on 
interest for 
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