Phase-locking of 19-core Yb3+ - doped optical fibre

The supermode generation in a multicore optical fibre laser can be realised by phase-locking of radiation inside of the fibre. The model proposed by authors implies the achievement of supermode generation by exchanging radiation between the cores during the development of the laser action. The analysis of the impact of coupling value between the cores on phase radiation of particular emitters was considered. In the paper the phase-locking of 19-core optical fibre doped with Yb3+ ions is presented. The analysis of material and geometrical parameters of the active 19 -core optical fibre and phase deviation on the beam quality factor of the laser beam in the far-field diffraction region has been analysed. The beam quality factor of the manufactured multicore fibre equals BQF = 0.71, V = 2.4, d = 18 ěm. As a result of the conducted analysis a double-clad 19 – cores optical fibre doped with ytterbium ions has been designed and fabricated and its luminescence spectra and far-field diffraction pattern have been measured. Registered in the experiment in MOFPA system far-field pattern showed centrally located peak of relatively high radiation intensity together with smaller side-lobes, and as such was similar to the pattern which had been obtained numerically.