Osram semiconductor laser wins Lab record for brilliance
Osram Opto Semiconductors has produced a broad area laser diode with a lateral brilliance of up to 4.8 W/(mm*mrad) - one of the highest known values for broad area laser diodes. This was part of the project "˜Integrated microoptical and microthermal elements for diode lasers of high brilliance' (IMOTHEB) funded by the German Federal Ministry of Education and Research.
The improvement was achieved by optimising the chip design, according to the company. In particular, by integration of microthermal and microoptical elements for beam shaping on chip.
Brilliance is a measure of the combination of optical output power and beam quality. Brilliant laser sources generate a narrow beam of light with extremely small beam divergence and high power density - a property crucial for the efficiency of fibre-coupled laser systems. The more brilliant the laser, the more light can be injected into an optical fibre.
An important application of fibre-coupled lasers is the pumping (injection of optical energy) of high-power lasers for material processing. Fibre lasers in particular are gaining in importance, for example for cutting and welding sheet metal in the automobile industry. At the same time, there is growing pressure on costs.
The aim of IMOTHEB was therefore to reduce the system costs for such pump modules. Project partner DILAS Diodenlaser researched concepts for the automated assembly of diode lasers. Another key factor was the brilliance of the laser sources. DILAS used a demonstration module to show that the improved Osram chips were capable of increasing the output power of the module by ten percent.
"Because the chip is more brilliant, more light goes into the fibre", explained Alexander Bachmann, project coordinator at Osram Opto Semiconductors. "The same module produces a higher output power than is possible with the laser diodes currently used in this application."
The IMOTHEB research project aimed at an increase of the efficiency of laser systems and a reduction of their production costs. The project (FKZ 13N12312) started in October 2012 and was part of the German 'Integrated Microphotonics' initiative. Osram Opto Semiconductors coordinated the project. The other partners were DILAS Diodenlaser and the Max Born Institute.
