Progress in green disk laser development for industrial high power applications

Green disk lasers are the superior tool among industrial lasers operating in the visible wavelength regime, whenever a combination of high power and very good beam quality is desired. We report latest lab and application results, showing the potential of the technology beyond today´s commercially available products and use cases. TRUMPF´s green TruDisk lasers are based on a well-established and proven thin disk oscillator design with an added internal-resonator nonlinear crystal for the generation of second harmonic of 515 nm. Power level and beam parameter product of these devices have significantly been improved recently, leading to a commercially available product of 2 kW in combination with a 100 µm fiber core diameter and NA 0.1. Here, we report results on our new 3 kW green TruDisk laser, showing the progress achieved in making this power-enhanced laser a stable, reliable tool for industrial applications. Moreover, lab results will be presented that indicate the potential for further power scaling beyond 3 kW output power. The benefits of visible laser light in comparison to standard IR laser wavelengths around 1000 nm in terms of machining highly reflective materials are demonstrated. Due to the much higher absorption at room temperature, process stability, efficiency and reproducibility are significantly improved. The green laser light enables spatter-free weld connections of copper parts, and welding in heat conduction mode, such as on multiple layers of copper foils. This makes green TruDisk lasers an extremely versatile and easy-to-use tool for a range of applications, for example in the context of eMobility and power storage.