Beam Quality Analysis of Incoherent Beam Combining by a $7\times 1$ All-Fiber Signal Combiner

Beam combining is one of the most potential methods to break through the output power limitations of a single fiber laser. In this letter, we report a high-power experimental result achieved by incoherent beam combining based on a 7 × 1 all-fiber signal combiner. The final output power is 6.26 kW with high beam quality (M
²
≈ 4.3). Beam quality of the incoherent combination laser is analyzed both by theory and experiment in details. Experimental measured values fit well with the simulation results. These results can demonstrate the feasibility of high-power high-brightness incoherent beam combining based on all-fiber signal combiners.