Hierarchical concentric surface patterns and metasurfaces on azobenzene molecular glass films using axicon interference lithography

Bessel laser beams generated by an axicon lens were used for the fabrication of hierarchical concentric surface patterns onto azobenzene molecular glass thin films. The resulting structures were characterized in details by atomic force and scanning electron microscopy, as well as surface profilometry, as the fabrication parameters were modified during the laser inscription process. It was found that the hierarchical concentric surface patterns on the azobenzene film reached overall heights that are surprisingly 5 times larger than the original film thickness. The presented axicon interference lithography technique was also used to fabricate novel metasurfaces on azobenzene thin films.