Innovations in high power fiber laser applications

Abstract

Diffraction-limited high power lasers represent a new generation of lasers for materials processing, characteristic traits of which are: smaller, cost-effective and processing "on the fly". Of utmost importance is the high beam quality of fiber lasers which enables us to reduce the size of the focusing head incl. scanning mirrors. The excellent beam quality of the fiber laser offers a lot of new applications. In the field of remote cutting and welding the beam quality is the key parameter. By reducing the size of the focusing head including the scanning mirrors we can reach scanning frequencies up to 1.5 kHz and in special configurations up to 4 kHz. By using these frequencies very thin and deep welding seams can be generated experienced so far with electron beam welding only. The excellen t beam quality of the fiber laser offers a high potential for developing new applications from deep penetration welding to high speed cutting. Highly dynamic cutting systems with maximum speeds up to 300 m/min and accelerations up to 4 g reduce the cutting time for cutting complex 2D parts. However, due to the inertia of such systems the effective cutting speed is reduced in real applications. This is especially true if complex shapes or contours are cut. With the introduction of scanner-based remote cutting systems in the kilowatt range, the effective cutting speed on the contour can be dramatically increased. The presentation explains remote cutting of metal foils and sheets using high brightness single mode fiber lasers. The presentation will also show the effect of optical feedback dur ing cutting and welding with the fiber laser, how those feedbacks could be reduced and how they have to be used to optimize the cutting or welding process

New concept to aid efficient fibre integration into metal matrices during ultrasonic consolidation

“…Fibre lasers as the laser source were chosen due to the excellent beam quality, the nearly diffraction-limited beam and high brightness, which allowed focusing of the laser to small spot sizes and hence, a high power density input (Table 2) which was necessary as aluminium exhibits a high reflection coefficient and high thermal conductivity. 15–18 The nearly diffraction-limited beam allowed a Gaussian-shaped heat input into the material. It was proposed that higher-order modes would modify the heat input into the material, which could possibly make the flow pattern of the melted material more difficult to control.…”

2D and 3D Triangulation Are Suitable In Situ Measurement Tools for High-Power Large Spot Laser Penetration Processes to Visualize Depressions and Protrusions before Perforating

“…Lasers are currently widely used in material processing, such as cutting, welding, or surface modification [ 1 , 2 ]. The used laser spot sizes are in the range of sub-millimeters up to some millimeters.…”

Laser manufacturing of electrical machines

“…This technology distinguishes itself by a minimal thermal degradation and an average cutting speed that exceed the conventional technique's cutting speed by a factor of up to five [6], especially for smaller parts with a higher complexity. For cutting larger parts there is the possibility to enlarge size of treated area by using additional x-y-axis which provides movement of the material [7].…”