EP2624031

The method comprises coupling a laser beam (2) with one end of a multi-clad fiber (1) such as a double-clad fiber, decoupling the laser beam from the other end of the multi-clad fiber, and selectively coupling the incident laser beam either with an inner fiber core (4) of the multi-clad fiber or with an outer annular core (6) of the multi-clad fiber for generating differing beam profile characteristics of the decoupled laser beam (3). A relative movement takes place in a direction transverse to the laser beam. The method comprises coupling a laser beam (2) with one end of a multi-clad fiber (1) such as a double-clad fiber, decoupling the laser beam from the other end of the multi-clad fiber, and selectively coupling the incident laser beam either with an inner fiber core (4) of the multi-clad fiber or with an outer annular core (6) of the multi-clad fiber for generating differing beam profile characteristics of the decoupled laser beam (3). A relative movement takes place in a direction transverse to the laser beam for selectively coupling the laser beam of the multi-clad fiber between the incident laser beam and a coupling-face of the multi-clad fiber. The incident laser beam with different beam cross sections or with different beam diameters is arranged on the coupling-face of the multi-clad fiber for selectively coupling the laser beam with the multi-clad fiber. The incident laser beam is split into two beams for coupling the laser beam with the inner fiber core and the outer annular core. An independent claim is included for an arrangement for changing beam profile characteristics of a laser beam.