Activation Line 300: Great atmosphere for surfaces

DORTMUND, GERMANY: Today, lasers are considered extremely versatile systems - systems believed to be capable of virtually anything by those outside the field. But now, at Dortmund-based LIMO, there is suddenly talk of using a laser source for surface heating which will surely astound even seasoned photonics experts. It involves a special application of the Activation Line 300, the most powerful L³ LIMO Line Laser source.

"Imagine that a surface with a functional layer only a few micrometers thin is to be heated to over 1000°C," says Dipl.-Ing. Dirk Hauschild, director of Thin-Film Activation at LIMO Lissotschenko Mikrooptik GmbH in Dortmund.

"And think about doing this with a substrate that is already destroyed at 500°C." But it doesn't stop there: The layers that are to be optimized are often composed of small particles or molecules which lose their desired properties and structural size just a few seconds after the processing temperature has been reached.

Here, there is a demand for fast and targeted heating and cooling. This challenge can be met with the use of an in-line high-temperature process that provides targeted surface heating in a matter of milliseconds. The Activation Line 300 was specifically designed to fill this need. With its high electro-optic energy efficiency of over 40 percent, the most powerful L³ LIMO Line Laser (a CW output of over 13kW with a homogeneous line focus 300 mm long) heats even the thinnest functional layers (thicknesses of over 0.1 µm to more than 100 µm) with an intensity of 40kW/cm² in a few milliseconds - delivering outstanding precision and consistency (beam quality M² < 3 in the processing direction) in the process.

Because of the low thermal capacity, the layers also cool down again very quickly. "The laser energy thus serves to functionalize the layer and, as a result, add to its value," says Dirk Hauschild. "Thanks to the targeted irradiation using the laser line profile, the user can uniformly temper large surface areas. The Activation Line 300 thus enables customized annealing, crystallization and sintering processes with fully closed surfaces."