Far-field lithography through saturated resonance energy transfer.

A method based on resonance energy transfer in a donor-acceptor pair is proposed for writing three-dimensional features in the far field. The saturation of the energy transfer between the donor-acceptor pair induces a nonlinear intensity response in the radical population. This optical nonlinearity can enable three-dimensional nanofabrication without requiring the use of the ultrafast excitation that is compulsory for non-resonant multiphoton excitation. Addition of a second, spatially shaped beam can enable nanopatterning far below the diffraction limit.