Propagation of broadband coherent light through LIPSS-based metasurfaces in diamond

Abstract

We study the propagation of coherent broadband light through laser induced periodic surface structures (LIPSS) fabricated on diamond surfaces. 3D finite-difference time-domain (FDTD) simulations were carried out for a variety of experimentally produced LIPSS morphologies, which include the specific nanometer-scale mesoscopic irregularities arising from the fabrication technique. We compare their performance with sinusoidal grating-like structures, showing that the specific features present in LIPSS nanoripples produce a considerable scattering and diffraction when compared to the ideal nanostructures. With a view on determining the scope of the potential optical and photonic applications of LIPSS, we evaluate the effect of these irregularities on the transmitted spatial beam quality and the spatial phase characteristics of the optical wavefront in a broad spectral range.