| Abstract [eng] |
The improvement of materials suitable for rapid laser processing is currently of huge interest in science. In this work three dimensional laser lithography (3DLL) of a negative photopolymer (silicon/zirconium hybrid sol–gel SZ2080) enhanced by doping it with gold nanoparticles (Au NP) is performed employing a 515 nm, 200 kHz and 300 fs amplified laser system. The Au NP are generated via pulsed laser ablation in liquids (PLAL) and sized around ~7 nm. The effect of doping is explored - by varying the nanoparticle concentration from 4.8e-6 wt% to 9.8e-3 wt% it is found that the fabricated line widths are both enlarged and diminished. The increase in feature size by up to 14.8% (when doped with 3.9e-3 wt% Au NP) compared to structures achieved in pure SZ2080 is observed. Explanation based on interplay of Au NP caused extinction, plasmonic near field enhancement and laser induced nonlinear light-matter interaction granting discussed phenomena is given. While implicating both positive and negative effect on the photosensitivity, the doping has no adverse impact on the mechanical quality of intricate 3D microstructures produced from the nanocompound. Additionally, we found that SZ2080 increases the long term (~months) colloidal stability of Au NP in isopropanol. These results promise a simple way of controlling photosensitivity of laser processable material with low (~0.001 wt%) dopant concentrations which is particularly interesting in the field of ultrafast laser material processing. |
