High resolution femtosecond direct laser writing with wrapped lens

This is the authors' abstract. We don't add key points for this paper.

Wrapped writing mode is a simple, inexpensive approach to multiphoton stereolithography. Standard ∼10 µm thin cling foil shields the objective from direct contact with the photoresist, without compromising writing resolution. A diffraction limited lateral voxel width below 150 nm was demonstrated through ray tracing simulations and electron microscopy using standard polymer photoresist. Wrapped mode, like dip-in printing, is not limited by the objective working distance height. Its utility to prototype new print resists was validated through custom aqueous protein, silver nitrate, and black epoxy based formulations.