Structured polarized laser beams for controlled spiral-shaped mass transfer in azopolymer thin films.

We present an approach for the realization of controlled spiral-shaped mass transfer in azopolymer thin films and the fabrication of spiral microreliefs. For such laser processing, we propose to use light fields with structured polarization distributions generated by a transmissive spatial light modulator. The projection lithography approach is utilized, transferring the pattern directly to the surface of azopolymer thin films. The shaped polarization distributions with different dependencies of the polarization vector orientation on the azimuthal angle allow us to drive surface waves on the sample along a spiral trajectory. Additionally, the ability to control the concavity of the formed microreliefs is demonstrated. This approach can be effectively modified for the direct laser fabrication of more complex nano-/micro-elements as well as their arrays.