Metasurfaces for the infrared spectral range fabricated using two-photon polymerization

Fabrication of metasurfaces is often time consuming and expensive, involving complex lithographic processes. The maskless fabrication of metasurfaces composed of rectangular Au bars is reported as a suitable alternative, providing cost-effective, rapid prototyping of metasurfaces. The investigated metasurfaces were fabricated using a simple three-step process which is discussed in detail. The fabrication process establishes a simple method for producing high fidelity 2D patterns suitable to synthesize metasurfaces for chemical sensing, beam steering, and perfect reflection/transmission. Comprehensive polarization-sensitive reflection data reveal multiple resonances in the infrared spectral range. In addition to the dipole and substrate resonances, a resonance which is attributed to a coupling between the excitation of the metasurface and the substrate phonon mode is observed.