Introduction
For decades, nuclear fusion has been heralded as the ultimate clean energy source. The same process that powers the Sun, capable of producing vast amounts of electricity with minimal fuel and no carbon emissions. While many fusion approaches rely on powerful magnetic fields to confine superheated plasma, another takes a dramatically different route: using some of the world’s most powerful lasers to trigger tiny, controlled fusion reactions.
Known as laser fusion, or inertial confinement fusion, this technology has moved from scientific theory to experimental reality. Recent breakthroughs have demonstrated that fusion ignition is possible in the laboratory, marking a milestone that many researchers have pursued for generations. Although significant engineering challenges remain before laser fusion can become a practical power source, these advances have renewed optimism that fusion energy could one day play a major role in the world’s transition to low-carbon electricity.
Phoenix (the largest privately owned laser)
On 3rd June 2026, Xcimer Energy announced the start of operations for Phoenix, the largest privately owned laser system in the world. The Phoenix laser system is the first step in Xcimer’s roadmap toward commercial fusion energy.
Phoenix is housed in Xcimer’s 74,000-square-foot Denver laser facility and is a proof-of-concept for unconventional fusion architecture. A krypton fluoride (KrF) excimer laser combined with Stimulated Brillouin Scattering (SBS) is used to compress a microsecond-long pulse into the nanosecond timescales required for fusion reaction.
How the technology was almost lost?
The industrial capabilities of large-scale laser systems in the United States was largely abandoned after the Cold War. As a result, specialised supply chains needed to be restored, engineers with direct experience in advanced laser systems were difficult to come by, and the transfer of that knowledge to a new generation of researchers was time consuming.
Backed by investors and funding from the U.S. Department of Energy, Xcimer spent four years assembling an enormous collective of fusion and laser expertise. Engineers, physicists, pulsed-power specialists, and technicians were brought together from national laboratories, the National Ignition Facility (NIF), aerospace, military, and past governmental departments.
The U.S. Naval Research Laboratory, which built and operated the only two remaining large-scale KrF excimer laser systems in the United States, preserved critical technical knowledge that helped bridge the gap between earlier government programs and today’s renewed commercial efforts for sustainable energy production.
Proof-of-concept to commercial reality
In 2022, the NIF demonstrated a net energy gain from a fusion reaction, and in 2025 produced a remarkable 8.6 megajoules of fusion energy from 2 megajoules of laser input. A considerable milestone on the road to making fusion energy a reality.
However, NIF was a mere research facility, not a commercial power plant. Furthermore, the laser architecture used to achieve this feat of engineering was solid-state glass, and as a result was expensive, complex, and maintenance-intensive. Electrical generation on a grid-scale required something considerably more economical.
Xcimer believes fusion, as a commercial endeavour, requires a fundamentally different industrial system. Krypton fluoride excimer lasers are designed for higher efficiency, fewer beamlines, lower thermal stress, and compatibility with industrial-scale manufacturing. The architecture uses two beamlines rather than NIF’s 192 and is specifically designed to reduce operational complexity and maintenance requirements.
The future for Xcimer Energy
Phoenix is just the first step in Xcimer’s roadmap toward commercial fusion energy.
- Anvil (2028): Commercial-scale excimer amplifier delivering 200 kilojoules on target in a complete two-sided beamline.
- Vulcan (early 2030s): 4–12 megajoule laser system targeting wall-plug breakeven and supporting high-energy-density and national-security applications.
- Athena (mid-2030s): Commercial-scale laser fusion power plant designed for continuous grid-scale electricity generation.
Athena
On 10th June 2026, one week after Phoenix was officially launched by Xcimer Energy. The U.S. Department of Energy (DOE) formally approved the company’s preconceptual design and technology development for Athena.
Athena is Xcimer’s architecture for commercial-scale fusion power plants. Xcimer are developing real-world requirements of power plants, which are expected to operate continuously for decades. Following the completion of early milestones, the company’s next phases of work include full-scale subsystem testing, engineering validation, and preparation for an integrated plant demonstration.
The Milestone-Based Fusion Development Program is part of the DOE’s broader effort to accelerate the commercialisation of fusion-based energy. A select group of companies are participating in the program, each pursuing different avenues of technical approach in order to achieve commercially viable fusion power. Safe, clean, sustainable and significant power supplies are a necessity in the current technological age, and will become all the more essential in the coming decades as Artificial Intelligence (AI) and quantum computing become commonplace. The global climate, environmental and political, is already at breaking point. Global temperatures have risen considerably, and conflict over the planet’s natural (and depleting) resources is cause for great concern. It is imperative for our own survival that environmentally friendly and sustainable energy is the top priority for researchers, lawmakers and governments worldwide.
