Laser Diode Research Project

Project DioHELIOS and HOTSTACK are leading initiatives advancing high-power laser diode technology for fusion energy and high-energy laser applications.

Project DioHELIOS

Project DioHELIOS is a German Federal Ministry of Education and Research (BMBF)-funded initiative under the Fusion 2040 program, aiming to develop high-power laser diodes for future fusion power plants . The project brings together ams-OSRAM, Ferdinand-Braun-Institut (FBH), Fraunhofer ILT, Jenoptik, Laserline, and TRUMPF to enhance the power, efficiency, and automated mass production of diode laser modules. Key goals include:

• Increasing pulse efficiency by a factor of 50 while improving overall energy efficiency.
• Achieving homogeneous and stable spectral properties for reliable operation.
• Developing diode laser modules capable of mass production at costs below one cent per watt.
• Ensuring long-term operation (~30 years) at repetition rates around 15 Hz. These modules are essential for laser-based inertial confinement fusion, where large quantities of diode lasers are required to ignite fusion plasma efficiently .

HOTSTACK Project

The HOTSTACK project, coordinated by TRUMPF and involving FBH, focuses on high-power diode laser stacks for ultrashort optical pulses in the megawatt to petawatt range . These stacks are critical for applications in material processing, spectroscopy, imaging, and high-energy laser research. The project aims to:

• Increase average pump power per stack by factors of 20–100 through higher pulse repetition rates and optical pulse power.
• Develop cost-effective fabrication processes using advanced die bonding and automated production.
• Support next-generation laser systems, including research facilities like EuPRAXIA. The HOTSTACK project emphasizes thermal management, precise assembly, and process control to ensure high performance and reliability of diode laser stacks .

Applications and Impact

Both projects contribute to climate-neutral energy generation and high-energy laser technologies:

• Fusion energy: Laser diodes are used to pump laser amplifiers that ignite deuterium-tritium plasma, releasing energy far exceeding the input laser energy .
• Industrial and scientific lasers: High-power diode stacks enable ultrashort pulse lasers for advanced manufacturing, spectroscopy, and imaging .
• Automated production: AI-assisted manufacturing and process optimization aim to reduce costs and scale production for large-scale applications . These initiatives represent a strategic push in photonics and energy research, positioning laser diodes as a cornerstone technology for both future fusion power plants and high-energy laser systems.