The LIMO presentation at the Photonics West event in San Francisco in February 2014 involves a small, but important piece of the large puzzle that is the move towards alternative energy. There, the LIMO g2T scan system will be celebrating its US premiere. This compact "Gaussian-to-Top Hat" converter with integrated scanning technology is perfect for the quick and precise laser structuring of six-inch solar wafers.
"Our all-in-one module makes it possible to locally structure solar cells faster, more accurately and, as a result, more cost-effectively than before," said Dr. Oliver Homburg, Director for Advanced Optical Solutions at LIMO Lissotschenko Mikrooptik GmbH in Dortmund. "The keys to this are the scan speed, the quality of the written lines, and the flexibility to freely program and quickly modify the cell design."
LIMO introduced its comprehensive solution for users in the photovoltaics industry in early 2013. The system is specifically designed for laser direct structuring with single mode lasers (532 nm). Thanks to its 160 by 160 mm² scan field (spot size of 75 x 75 µm²), the system is primarily suitable for use in the structuring of solar cells.
What is the technical secret behind the system? "The g2T scan system combines the advantages of two different optical concepts," says Dr. Homburg. "First, it converts Gaussian beams into homogeneous "top hat" profiles, which provide high-precision grooves with extremely smooth edges instead of the otherwise typical sawtooth pattern. Secondly, the system has a closed optical core with integrated galvo mirrors and a custom-made F-theta lens." Thanks to the combination of these two technical concepts, the g2T scan system is able to structure material at very high speeds (over 20 m/s) while providing incredible accuracy and significantly increased process stability. The latter feature, along with the system's upgrade capability to be used in-line, is particularly important to photovoltaics manufacturers. In addition, a control unit is also available to simplify the module's integration into existing systems.
Those interested in learning more about this alternative kind of optical core technology can visit LIMO at the 2014 Photonics West (South Hall, booth #2233) to be held February 4 - 6 in San Francisco, CA.