Engraving depth-controlled nanohole arrays at the surface of glass by tailored laser beam processing

Arrays of nanoholes or nanochannels constitute the building block of integrated devices that open attractive applications like 2D photonic crystals, 2D metamaterials or nanostructured surfaces. Here we present a laser-based technique that enables to generate short-length micro-Bessel beams (irrespective of their core diameter) that we further use to machine depth-controlled holes with a cylindrical depth profile. We illustrate the potential of this method by fabricating square arrays of subwavelength-diameter holes with several-micrometers depth by direct laser ablation at the surface of fused silica.