Lawrence Livermore National Laboratory (LLNL) and Germany's Fraunhofer Institute for Laser Technology (ILT) are joining forces to transition laser-ignited inertial fusion from experiments to industrial applications in a collaboration called ICONIC-FL (International Cooperation on Next-gen Inertial Confinement Fusion Lasers). Through a Cooperative Research and Development Agreement (CRADA) facilitated by LLNL's Innovation and Partnerships Office (IPO), the two institutions will cross-validate their sophisticated laser simulation models to leverage complementary expertise.
LLNL achieved fusion ignition in an experiment at its National Ignition Facility (NIF) in December 2022, demonstrating a foundational capability for its stockpile modernization mission but also the physics basis for a fusion-energy approach known as inertial fusion energy (IFE). Harnessing the same reaction that powers the sun, fusion promises a virtually limitless and reliable energy source, delivering unprecedented prospects for national and economic security. While LLNL continues to achieve ignition with increasing energy yields, significant technology development remains for IFE and advanced fusion systems. With this partnership, the United States and Germany are jointly laying the foundation for this future technology.
"The transition from basic research to power plant development requires the rapid, robust development of rugged new laser systems. Fraunhofer ILT's expertise in industrial scaling of diode-pumped lasers is crucial for accelerating our IFE program," said Tammy Ma, director of LLNL's Livermore Institute for Fusion Technology (LIFT). LLNL established LIFT in 2025 as a means of advancing innovative fusion technology partnerships across the fusion ecosystem, with laser driver technology representing a pillar of that approach.
Precise and highly accurate predictions of laser performance will be critical in developing the laser architecture for efficient power plant operations. Designs must be validated in simulations before expensive prototypes can be built.
"We are in the decisive decade for fusion energy. For inertial fusion to reach its full potential, we need to develop new laser architectures with uncompromising perfection. Combining the expertise of LLNL with the industrial scaling expertise of Fraunhofer ILT is a powerful response to this challenge. Here we are laying the foundation for future power plants," said Constantin Häfner, executive vice president for research and transfer at the Fraunhofer-Gesellschaft.
LLNL brings decades of experience in high-energy laser technology. This includes the NIF laser, and the High-Repetition-Rate Advanced Petawatt Laser System (HAPLS), the world's most advanced and highest average power, diode-pumped petawatt laser system. Next generation IFE laser architectures will involve diode-pumped solid-state lasers, like HAPLS, but with high energies like NIF.
Fraunhofer ILT is a global leader in the development and industrial scaling of efficient diode-pumped solid-state lasers (DPSSLs), which can fire dozens of times a second. Efficient, high-energy and high-repetition-rate lasers are essential to IFE power plant design.
The partners are pursuing the common goal of simulating the amplification stages of high-energy lasers in as much detail as possible, focusing on the heart of the system: the laser amplifiers. Critical to amplifying a small laser pulse to laser energies required for fusion, amplifier slabs are exposed to enormous thermal and optical stress.
"24/7 operation leads to heating, refraction effects and aberrations that could distort the laser beam. Even the smallest, unpredictable effects are significant here and lead either to efficiency losses or direct damage to the optics. We want to understand exactly what is happening in each individual slab so that we can then simulate complex slab stacks with precision," said Johannes Weitenberg, project manager at Fraunhofer ILT.
LLNL and Fraunhofer ILT will cross-validate their respective laser energetics codes used for DPSSL optimization to achieve increasingly detailed and realistic simulations. "Both institutions are leaders in laser science with outstanding modeling and simulation capabilities for high power DPSSL architectures. This project aims to increase confidence in the fidelity of both models and advance fusion energy," said Robert Deri, the LLNL principal investigator.
This methodical approach is valuable from scientific, technical and economic perspectives. The partners can guarantee robust and reliable predictions by independently applying their respective codes - developed to maturity in different fields of application - to the same design. This can accelerate the development of lasers for power plants and avoid costly missteps.
The two institutions have a history of collaboration, including experiments to optimize high-intensity, high-repetition rate lasers using machine learning. Fraunhofer ILT is also part of the STARFIRE Hub, a four-year, $16 million project led by LLNL to accelerate IFE commercialization, and a member of the STARFIRE Diode Technology Working Group.
LLNL is funded through the STARFIRE Hub, and Fraunhofer ILT is funded through Fraunhofer Gesellschaft internal International Cooperation and Networking program. Collaborations such as this illustrate the impact of technology transfer through public-private partnerships utilizing LLNL intellectual property (IP). LLNL's IPO, which facilitated the CRADA, is the Laboratory's focal point for industry engagement. IPO facilitates partnerships to deliver mission-driven solutions that support national security and grow the U.S. economy. LLNL Business Development Executive Alex Hess is responsible for the Laboratory's lasers and optics IP portfolio.
