Product Code: ICA13_204

Lasers with Line Focus Geometries As Universal Tool for a Wide Range of Surface Processing Applications
Authors:
Jens Meinschien, LIMO Lissotschenko Mikrooptik GmbH; Dortmund USA
Lutz Aschke, Limo Lissotschenko Mikrooptik Gmbh; Dortmund
Mikhail Ivanenko, Limo Lissotschenko Mikrooptik Gmbh; Dortmund
Presented at ICALEO 2013

The herewith presented approaches are relevant for a large range of applications were surfaces or thin films are treated by scanning processes in large scale, e.g. photovoltaics, flat panel displays production, drying and annealing surfaces. Such laser systems can be implemented into inline-processes, and efficiently replace in some technologies oven processes. The energy consumption for thermal processes on surfaces can be reduced to 25% or less compared to standard heat treatment procedures. It is even possible to treat thin films to temperatures exceeding 1000 °C on top of sensitive substrate materials, e.g. melting silicon layers on glass substrates.
Novel configurations for line generators of high power diode lasers are presented which take into account high demands particularly for three key parameters: high power density per line length (20…60 W/mm), small line width (50 µm … 200 µm) and scalability to very long line lengths (1 m and more). These parameter sets are proven on small scale test systems to be vital for surface processing applications which can only be reasonably implemented by laser technology.
Furthermore, line shaping optics for green and UV DPSS lasers are reviewed and exemplary two optical systems are presented. Both the systems provide ultra-homogeny line focus of 200-mm length. The first system uses two lasers and shapes a line of only 8-µm width, while the other one couples 8 lasers in the line of 100-µm width. In the first case a micro-optical anisotropic beam transformation technique is applied to reach the strong focusing and long depth of the focus. The second system meets the challenge of the coupling of a large number of high-power fibre delivered beams.