Ph. D. THESIS 2009

6. Conclusions of part B
In this work, we developed and optimized a direct and versatile pathway to
fabricate metallic structures based on a metallic photo-reduction process
induced by femtosecond laser irradiation.
The fabrication process is very sensitive to the „writing” conditions, the
chemical composition of the active layer as well as the laser power are found to
have a strong influence on the fabricated structures.
Continuous and regular metallic wires have been obtained in repeatedly and
reproducible way. AFM and SEM measurements show that gold and silver
wires are in fact constituted by two metallic lines –double-wire shape- centered
on the area of engraving and generated by the thermal effect.
The origin of the double-wire shape of the metallic wires has been
demonstrated and we showed that optimized experimental conditions allow to
generate a metallic single wire deposition.
This method allowed us to fabricate regular and well-defined 3D gold
microstructure embedded in a dielectric matrix as well as 3D self-standing
silver microstructure.
Optical and spectroscopic investigations highlighted that the metallic
structures obtained by us exhibit very important plasmon resonances showing
promising optical properties and challenging applications.
This direct writing technique may be useful to fabricate highly efficient 3D
gratings with spectral filtering properties due to the significant index contrast
between polymer host and metallic parts.
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