Combined phase locking and beam shaping of a multicore fiber laser by structured mirrors

We present a novel mirror geometry combining the two features of phase locking and simultaneous beam shaping of the emission of a multicore fiber (MCF) laser. In the experiments we applied a Talbot cavity to a diode-pumped MCF laser with 18 microcores placed on a ring. The feedback mirror consisted of a highly reflecting structure with 18 spokes and a circle in the center deposited on a glass substrate. The spokes increased the discrimination between the supermodes and suppressed independent lasing of the individual emitters. The central dot caused strong diffraction of the output radiation, leading to a shaped beam profile. The output power of the phase-locked MCF laser exceeded 5 W. (C) 2001 Optical Society of America.