  Plasmonic metasurfaces based on the extraordinary optical transmission effect
(EOT) can be designed to efficiently transmit specific spectral bands from the
visible to the far-infrared regimes, offering numerous applications in
im-portant technological fields such as compact multispectral imaging,
biological and chemical sensing, or color displays. However, due to their
subwavelength nature, EOT metasurfaces are nowadays fabricated with nano- and
micro-lithographic techniques, requiring many processing steps and carried out
in expensive cleanroom environments. In this work, we propose and
experimentally demonstrate a novel, single-step process for the rapid
fabrication of high performance mid- and long-wave infrared EOT metasurfaces
employing ultrafast direct laser writing (DLW). Micro-hole arrays composing
extraordinary transmission metasurfaces were fabricated over areas of 4 mm2 in
timescales of units of minutes, employing single pulse ablation of 40 nm thick
Au films on dielectric substrates mounted on a high-precision motorized stage.
We show how by carefully characterizing the influence of only three key
experimental pa-rameters on the processed micro-morphologies (namely laser
pulse energy, scan velocity and beam shaping slit), we can have on-demand
control of the optical characteristics of the extraordinary transmission effect
in terms of transmission wavelength, quality factor and polarization
sensitivity of the resonances. To illustrate this concept, a set of EOT
metasurfaces having different performances and operating in different spectral
regimes has been successfully designed, fabricated and tested. Comparison
between transmittance measurements and numerical simulations have revealed that
all the fabricated devices behave as expected, thus demonstrating the high
performance, flexibility and reliability of the proposed fabrication method.
