Generating physical modifications by means of laser in the interior of a solid body

The present invention relates to a method for generating a physical modification, in particular of a lattice defect or to the local change of resistance in a solid state, in particular an ingot or a wafer. The inventive method comprises at least the steps of: - providing the solid body to be treated (2), - providing a radiation source assembly (4) for generating at least one light beam (6), - providing a lens (8), wherein the optical system (8) at least two deflection elements (10, 12) for redirecting light beam portions (16, 18), - generating and emitting at least one light beam (6) by the radiation source assembly (4), - diverting at least two mutually different light beam portions (16, 18) of the emitted light beam (6) by means of the deflection elements (10, 12), wherein the light beam portions (16, 18) are deflected such that they penetrate into the solid body (2), and wherein the mutually different deflected light beam portions (16, 18) in a focus (20) within the fixed body (2) coincide and the physical modification (1), in particular in the form of a lattice defect, coincident with the focus (2) light beam components (16, 18 ) is produced.