The propagation of graphitization wave through the diamond bulk under multipulse laser irradiation is a largely self-guided process. This fact assists the production of graphitized wires oriented along a laser beam and greatly complicates formation of the structures oriented differently. Here, we develop new approaches to control laser graphitization that should empower the potential of 3D laser microstructuring inside a diamond crystal. Two techniques are investigated: (i) a laser seed damage of crystal with subsequent exposure at a lower laser fluence, thus restricting the propagation of the graphitization wave toward the beam and (ii) formation of a dominant microfracture perpendicular to the laser beam, thus guiding growth of the graphitized thread.
