Industrial lasers used for materials processing have become essential tools in a wide array of applications, including cutting, welding, drilling, cladding, marking, hardening, and additive manufacturing. The speed, quality, and process window are determined in part by the laser beam properties such as beam size, shape, and divergence. nLIGHT has developed a new multi-kilowatt fiber laser, Corona™, that provides rapid tunability of the beam characteristics directly from the laser output fiber using a novel, all-fiber mechanism. Programmable beam shapes include flat top and donut beams with beam diameters from 100 μm to 390 μm and beam parameter products from 3 to 20 mm-mrad (M<sup>2</sup> values from 9 to 59). We describe the Corona fiber laser performance and show processing results and advantages of specific beam shapes for sheet-metal cutting, the largest industrial laser application.
Next-generation industrial fiber lasers enable challenging applications that cannot be addressed with legacy fiber lasers. Key features of next-generation fiber lasers include robust back-reflection protection, high power stability, wide power tunability, high-speed modulation and waveform generation, and facile field serviceability. These capabilities are enabled by high-performance components, particularly pump diodes and optical fibers, and by advanced fiber laser designs. We summarize the performance and reliability of nLIGHT diodes, fibers, and next-generation industrial fiber lasers at power levels of 500 W – 8 kW. We show back-reflection studies with up to 1 kW of back-reflected power, power-stability measurements in cw and modulated operation exhibiting sub-1% stability over a 5 – 100% power range, and high-speed modulation (100 kHz) and waveform generation with a bandwidth 20x higher than standard fiber lasers. We show results from representative applications, including cutting and welding of highly reflective metals (Cu and Al) for production of Li-ion battery modules and processing of carbon fiber reinforced polymers.