Jul 27 2007
A new world record has been set by laser bars with a wavelength of 808 nm – 64% efficiency at an optical output of 120 W.
Osram Opto Semiconductors set the new record together with the laser specialists DILAS as part of the “BRILASI” research project. The values were measured under laboratory con-ditions at room temperature and take into account the power losses of the elec-trical system.
The laser bars with enhanced output and efficiency are prototypes of a new generation of diode lasers. With outputs of 120 W, this will almost be double the value achieved at present for the 808 nm wavelength (60 W, 55% efficiency). Efficiency will also increase by around 10 percentage points.
The main application for these laser bars is to pump solid state lasers, which are used for example in the automobile industry for welding. With the new more powerful lasers not only the system output can be increased, with the same service life, but systems can be made smaller and more reliable for the same output. Applications may also be possible that were previously reserved exclusively for solid state lasers, such as surface processing.
The key to these record efficiency values and doubling of output is the combined know-how of Osram Opto Semiconductors with its vast experience of chip fabrication and DILAS with its skills in assembly and cooling systems. Success came from the various improvements in chip design and in the structure of the epitaxial layers, coupled with active water cooling.
The new generation of lasers is expected to be market-ready at the end of the research project in about 2008.
The “BRILASI” research project (Brilliant High-Power Laser Diodes for Industrial Applications) was initiated by the Germany Ministry for Education and Research. The main agency is the VDI (Association of German Engineers). Osram Opto Semiconductors is acting as the coordinator. The project team comprises various partners from the laser system and end user sectors and representatives from research institutes. The aim of the project is to develop highly efficient and reliable diode lasers for industrial applications. The requirements relating to lifetime at 110 W are in excess of 20,000 hours in constant or long pulse mode.