Renowned companies such as TRUMPF and Jenoptik participate in high-power laser projects in Germany

High power laser diodes will be key components of future fusion power plants.
Recently, the German Federal Ministry of Education and Research (BMBF) launched a new project called "DioHELIOS". The project will last for 3 years and is part of BMBF's "Fusion 2040" funding program, which aims to build the first nuclear fusion power plant in Germany by 2040.

The project will last for three years and receive funding support of 17.3 million euros. Its goal is to promote the application of high-power laser diodes in fusion power plants, which the German government expects to be built as early as the 2040s.

The DioHELIOS project brings together top institutions and laser optoelectronic manufacturers such as ams OSRAM, Ferdinand Brown Institute (FBH), Leibniz Institute for High Frequency Technology (HZDR), Fraunhofer Institute for Laser Technology (ILT), Jenoptik, Laserline, and TRUMPF to enhance the power and efficiency of high-power laser diodes and develop automated mass production processes to meet the enormous energy demand generated by laser inertial confinement fusion.

The above figure shows the most advanced diode stack, consisting of 25 semiconductor bars, with a focusing lens in the front and active cooling at the back. (Image source: TRUMPF)

The core of the project is to develop a beam shaping diode laser module for high-energy laser pumping plate stack amplifiers, which is considered a key component of future nuclear fusion power plants and is supported by the Fraunhofer Institute for Laser Technology (ILT) in Germany.

The project goal is to increase pulse efficiency by 50 times while improving overall efficiency and ensuring uniformity and stability of spectral characteristics. In addition, the project also pursues mass production at a cost of less than 1 cent per watt of power, and hopes that the hardware can operate stably for 30 years at a repetition rate of about 15 hertz.

During the project execution, Laserline and TRUMPF will build different pump modules for high-power laser pumping in the initial demonstrator. The alliance is committed to pushing diode laser based pump modules to the megawatt range.

Jenoptik, Osram, and Ferdinand Brown Institute (FBH), as leading manufacturers and developers of laser diodes, will contribute their expertise to drive innovation in semiconductor laser technology.

The Fraunhofer Institute for Laser Technology (ILT) in Germany uses its SEMSIS software to design and optimize diode laser rods, significantly increasing the output power of chips and ensuring their industrial production at the required cost level and resource efficiency.

The project team is seeking new design methods for diode lasers required for nuclear fusion power plants to stabilize the spectral distribution of laser beams and increase light production through a "multi junction" mode. They plan to significantly improve the efficiency of electron to photon conversion by stacking multiple active regions.

The optimized diode laser chip will be sent to TRUMPF, Laserline, and Jenoptik for building a diode laser stack with high packaging density and high irradiance. An efficient cooling system is crucial for ensuring long lifespan and avoiding temperature induced spectral drift. These stacks will serve as building blocks for pump modules, arranged in a two-dimensional array.

In addition, project partners are also studying the potential of optimizing current drivers to provide current pulses exceeding 1000 amperes and minimize losses as much as possible.

Meanwhile, the Fraunhofer Institute for Laser Technology (ILT) in Germany is developing specially optimized optical devices for automated assembly to collimate and homogenize beam profiles.

Optical components based on welding can achieve long-term stable beam shaping. In the future, AI will accelerate the adjustment of micro optics to achieve the required quantity of commercial power plants and reduce unit costs. (Image source: Fraunhofer ILT)
Ultimately, these partners will evaluate the scalability of the module to achieve higher output and pulse energy, while controlling system costs.

From: Yangtze River Delta Laser Alliance