Osram Coordinating Project For Developing High-Brilliance Infrared Laser Sources

Diode-pumped high-power laser systems for materials processing applications such as cutting and welding are playing an increasingly important role in industry. Their advantages over carbon dioxide lasers and lasers pumped with flash lamps include lower operating costs, greater efficiency and smaller size. Fiber lasers and fiber-coupled diode lasers are becoming more and more important for optical materials processing. As the lasers become more widespread, the focus is shifting to the issue of cost. Developments that increase the performance of laser systems, and at the same time reduce production costs, are necessary to move this market forward. Infrared semiconductor laser diodes that can be used to pump fiber lasers are key components in this area. They offer enormous potential for automating production and miniaturizing the systems while reducing the number of semiconductor chips needed thanks to the increased performance they provide.

The objective of the IMOTHEB project is to investigate new approaches and technologies that may ultimately lead to significant reductions in the cost of the pump modules, including the semiconductor lasers and also the cooling elements, optics and sensors. There are also plans over the course of the project to increase the output of semiconductor lasers by 40 percent while retaining the same high beam quality. IMOTHEB maps the entire value-added chain from the semiconductor chip to the complete laser system. The project partners bring their own specific areas of expertise:
• Osram Opto Semiconductors is coordinating the project and offering its know-how in semiconductors, laser diodes and laser bars; simulations are being subcontracted to the Fraunhofer Institute for Applied Optics and Precision Engineering.
• DILAS is responsible for the assembly technology with improved thermal resistance and higher integration in laser modules, as well as for automation in module production.
• The Max Born Institute is acting as a scientific partner, analyzing and characterizing the chips and modules.

Osram Opto Semiconductors has set the goal of achieving a higher degree of integration at the semiconductor level, increasing the brilliance of infrared laser diodes by integrating micro-optical and microthermal elements directly on the chip. Over the course of the project, the target is to increase output by 40 percent compared with current best values while retaining the same high emission quality. If these high outputs are achieved, they will make laser chips ideal for fiber laser pump modules and for fiber-coupled diode lasers. Dr. Alexander Bachmann, project leader at Osram, said: “We need results that bring not only technical but also economic benefits to strengthen our competitive position. Based on results from the project, our brilliant laser diodes should provide more output into the fibers so that fewer chips are needed in the system and the laser systems therefore become more efficient and more cost-effective.”

Higher output from laser diodes and new automated assembly processes for laser systems are targeted at industrial applications such as laser welding and laser cutting, making them more efficient and more cost-effective.