Next-generation of high-power, sub-300 fs lasers with >100 W for industrial applications

Summary form only given. Femtosecond laser systems are the enabling technology for cold ablation, a process that removes layers of material with virtually no thermal side-effects, and therefore leads to a superior quality without additional post-processing steps [1, 2]. Cold ablation can be applied to even the most complex and hardest to machine materials, like diamond, ceramics, polymers and metals, making the femtosecond laser system a universal tool for micromachining. However, in order to achieve high throughput, high pulse energies at high repetition rates, and therefore high average output power, is required [3].In this report we present a new industrial-grade, high-power, femtosecond hybrid MOPA (Master Oscillator Power Amplifier) laser system, combining the advantages of fiber technology with crystal-based booster amplifiers for power and energy scaling. This results in an average output power of >100 W at 1032 nm and >60 W after frequency conversion to 516 nm with exceptionally good beam quality factors M2 of <;1.10 at both wavelengths (see Fig. 1a). Pulses as short as 297 fs at 1032 nm and 291 fs at 516 nm can be achieved. Moreover, the design allows for flexibility both in repetition rate and pulse duration: single pulses up to 30 MHz repetition rate can be covered with pulse duration between ~300 fs and ~1.5 ps.