1 kW Fiber Lasers and Alignment Free SBC

Spectral Beam Combination (SBC) has been proven as a scalable beam combining approach for high power fiber lasers. Demonstrations at Aculight have shown 522 Watts of near diffraction limited power from three combined fiber laser sources; and the dispersive element, a Multi-Layer-Dielectric (MLD) diffraction grating, will operate well above 1.5 kWatts/cm2 of incident power allowing ~100 kWatt sources to be feasible with a relatively small grating of 10x10 cm2 while maintaining excellent beam quality. In this proposed work, Aculight will increase its single fiber laser power from ~300 Watts to over 1 kWatt, suitable for Spectral Beam Combination (SBC), delivering properties including: polarized output, narrow bandwidth, and diffraction limited beam quality. The laser will be all-in-fiber-pumped geometry (no free space pump components). An alignment-free SBC fiber tray assembly will be engineered and tested with the multiple ~300 Watt fiber lasers available at Aculight; and then tested using the 1 kWatt fiber laser to be demonstrated in the early part of this work. These results will enable a clear pathway to a 10 kWatt demonstration, and an eventual demonstration of SBC high power fiber sources to the 100 kWatt level.