The fusion energy sector is experiencing a significant shift, driven by advancements in high-temperature superconducting (HTS) tapes and the technology enabling their production. At the heart of this transformation is the LEAP series excimer lasers from Coherent, which are pivotal in manufacturing the superconducting tapes required in large quantities for high-field fusion magnets.
Magnetic confinement fusion has long struggled with the challenge of containing plasma at extreme temperatures. Traditional superconducting magnets, made from copper conductors or niobium-alloy-based low-temperature superconductors (LTS), have been the standard. However, the emergence of HTS tapes over the past decade has sparked a breakthrough. These tapes, based on multi-crystalline REBCO (rare-earth barium copper oxide) layers, can carry immense electrical currents while operating at higher temperatures and magnetic fields than LTS. This advancement has enabled the design of more compact, efficient, and powerful fusion reactors, with magnetic fields exceeding 20 T now achievable.
The scale-up of HTS production is critical to unlocking the potential of magnetic fusion energy. With nearly $10bn in mostly private funding, the fusion industry is rapidly advancing toward commercialisation. According to the Fusion Industry Association, 75% of all fusion companies expect to begin delivering electricity to the grid by 2035. Achieving this milestone will require the construction of many HTS-based magnetic fusion devices, consuming large amounts of HTS tape that easily exceeds the global HTS tape capacity currently at around 10,000 km per year by an order of magnitude.
In HTS tape manufacturing, the superconducting properties of a tape are largely determined by the quality of its few microns-thin REBCO layer. Various deposition methods have been employed to achieve smooth and homogeneous REBCO films with well-aligned crystal grains. Among these, Pulsed Laser Deposition (PLD) using excimer lasers stands out. PLD-deposited REBCO-films exhibit superior critical current density under high fields up to 20 T and beyond. Today, PLD is the dominating REBCO manufacturing method serving all types of HTS-based fusion magnets.
The advent of HTS-based fusion has sparked an unprecedented demand for PLD-REBCO films. Enter the LEAP excimer laser platform from Coherent, designed for fast large-area thin film processing. The LEAP platform, with increasing power levels up to 300 W at the required output wavelength of 308 nm, is now employed by all major HTS tape suppliers. To scale up tape manufacturing capacity, new fabs have been built, housing multiple LEAP 300 W-based PLD systems operating at maximum intensity and at an annual capacity of several 1000 km of HTS tape.
As HTS-tape demand is expected to soar with the next wave of prototype and grid-scale fusion reactors, Coherent has introduced the next generation LEAP at 600 W. The LEAP 600 W, introduced in June 2025 at the Laser World of Photonics Fair in Munich, is the most cost-effective PLD laser on the market. With its core innovations, performance and lifetime improvements, the LEAP 600 W is poised to become the linchpin of the imminent global HTS tape capacity expansion.
The LEAP 600C, a cutting-edge 600-watt excimer laser developed and produced at the Coherent excimer laser facility in Goettingen, Germany, operates at a 308 nm wavelength and is specifically designed for industrial-scale HTS tape fabrication. It features on-the-fly active injection technology, which triples runtime and doubles the HTS tape throughput per PLD system compared to previous LEAP 300 W-based REBCO deposition systems.
Scaling HTS tape production is still regarded by many fusion companies as a bottleneck to achieving their next fusion reactor milestones. The LEAP 600 has been introduced to the HTS tape market, with a clear focus on changing this picture. Equally important is meeting energy cost targets set by existing coal, gas, and nuclear power plants. As the magnets make up a large part of the reactor costs, HTS tape procurement will be guided significantly by the performance-price ratio. With these fusion market economics in mind, the LEAP 600 has been designed to provide unprecedented cost-efficiency and offers not only the highest power but also the lowest cost-per-watt-ratio of the LEAP excimer laser product family.
Innovative developments such as on-the-fly active gas injections significantly extend the intervals between gas replacements in the LEAP 600, allowing for significantly longer batch lengths and more consecutive batches between gas exchanges. Although the laser-related expenses are but a smaller fraction in the HTS tape manufacturing cost