Xcimer Energy Lights Up Phoenix: A New Chapter in Fusion Energy
Fusion startup Xcimer Energy has activated Phoenix, a krypton-fluoride excimer laser system the company calls the largest privately owned laser in the world. This milestone represents a significant step toward the company’s ambitious goal of developing a commercial laser-fusion power plant by the mid-2030s, marking a pivotal moment in the race to harness fusion energy.
What turned on
Phoenix generates over 1 kilojoule of energy at full strength, with a laser core stretching an impressive 38 metres long. This electron-beam-pumped excimer laser technology has not been built by any organization in over twenty years, making Phoenix a groundbreaking achievement. Notably, the system also demonstrates Stimulated Brillouin Scattering (SBS) pulse compression at the highest energy levels ever achieved using this technique.
The design architecture of Phoenix is crucial because it directly impacts cost efficiency. Xcimer’s approach fires long-pulse excimer lasers in microsecond bursts and then compresses the resulting light pulses down to nanoseconds before they reach the fusion fuel target. This rapid compression increases the likelihood of nuclear fusion by quickly compressing the fuel, which is essential for achieving ignition.
The NIF blueprint, rebuilt for economics
Xcimer’s strategy draws inspiration from the National Ignition Facility (NIF), which in December 2022 became the first system to demonstrate a controlled fusion reaction producing more energy than was input to initiate it. NIF focuses 192 laser beams onto a fuel target smaller than a pencil eraser, vaporizing a gold hohlraum to generate X-rays that then compress the fuel pellet until fusion occurs.
While NIF validated the physics of fusion ignition, it did not resolve the economic challenges. Its solid-state laser system is complex, expensive, and limited by slow shot rates due to thermal management issues. In contrast, Xcimer is betting on excimer amplification—a gas-based ultraviolet laser technology also used in deep-UV semiconductor photolithography—to deliver more energy per dollar. These gas-based systems inherently avoid many thermal constraints, enabling potentially faster cycling and lower operational costs compared to solid-state setups like NIF.
The gap between Phoenix and a power plant
Despite the impressive achievement, Phoenix’s 1 kilojoule output represents only a tiny fraction of the energy a commercial fusion reactor will require. Xcimer projects that future systems will need to exceed 12 megajoules—over 10,000 times more energy than Phoenix can currently produce. The company plans to complete a prototype by 2028, followed by a scaled system capable of producing at least as much power as it consumes. Their target for a first commercial-scale fusion power plant is the mid-2030s.
The institutional layer
The activation of Phoenix reflects a broader structural shift in fusion research. For decades, fusion experiments were almost exclusively the domain of state-funded mega-facilities such as NIF in California, ITER in France, and the Naval Research Laboratory’s Electra and Nike systems. Today, private capital is building hardware on scales once reserved for national laboratories. The excimer laser technology originally developed in the 1980s for inertial confinement fusion is being revitalized by venture-backed startups like Xcimer, which are working toward commercial timelines.
Xcimer is among eight companies supported by the DOE’s Milestone-Based Fusion Development Program, a public-private partnership designed to accelerate the path to fusion pilot plants. This transition from public research and development to private capital expenditure represents a critical evolution in the fusion energy landscape. Ultimately, the ownership of the laser systems will determine the supply curve for fusion-generated energy, potentially reshaping global energy markets.
Today, Phoenix delivers one kilojoule, but the architecture it validates is what truly matters. Investors and industry watchers alike are buying into the promise of scalable, economically viable fusion energy, with Xcimer Energy leading a new wave of innovation in the field.
Source: Here
