Xcimer Energy today announced the start of operations for Phoenix, the largest privately owned laser system in the world and the company’s prototype for commercializing laser fusion.
Phoenix, housed in Xcimer’s 74,000-square-foot Denver laser facility, is a proof of concept for an unconventional fusion architecture: a krypton fluoride (KrF) excimer laser using Stimulated Brillouin Scattering (SBS) to compress a microsecond-long pulse into the nanosecond timescales fusion requires.
Phoenix successfully demonstrates end-to-end integrated operation of excimer amplification and SBS pulse compression. The light source for Phoenix operates at pulse energies over 1 kJ, and the SBS gas optic at the core of Phoenix is 38 meters long. This is the highest-ever energy and largest spatial extent of SBS in an optical system.
Designing, building and operating Phoenix required Xcimer to rebuild industrial capabilities around large-scale electron-beam-pumped excimer lasers – a competence that was in danger of disappearing after the Cold War.
Backed by venture investors and funding from the U.S. Department of Energy, Xcimer spent four years assembling one of the world’s deepest concentrations of fusion and laser expertise, recruiting engineers, physicists, pulsed-power specialists, and technicians from national laboratories, the National Ignition Facility (NIF), commercial aerospace, the U.S. Navy, and past government excimer laser efforts. (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.)
“We had to rebuild an industrial capability the United States largely abandoned after the Cold War, restoring specialized supply chains, recruiting many of the last engineers with direct experience in these systems, and transferring that knowledge to a new generation,” said Conner Galloway, co-founder and CEO of Xcimer. “Phoenix represents both a technical milestone and the reindustrialization of high-energy excimer lasers in America.”
The physics and the economics
Laser fusion is the only fusion approach to achieve scientific breakeven in a laboratory. In 2022, the NIF demonstrated net energy gain from fusion, and in 2025 produced 8.6 megajoules of fusion energy from 2 megajoules of laser input.
But NIF was built as a scientific research facility, not a commercial power plant. Its solid-state glass laser architecture is too expensive, complex, and maintenance-intensive for economical grid-scale electricity generation.
Xcimer believes commercial fusion requires a fundamentally different industrial system. Its 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 designed to reduce operational complexity and maintenance requirements.
“NIF proved laser fusion physics works,” said Xcimer co-founder and President Alexander Valys. “Our thesis is that commercial laser fusion becomes possible only if the laser system itself becomes dramatically simpler, cheaper, and more manufacturable.”
What comes next
Phoenix is 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. Xcimer expects to select a Vulcan site this year.
- Athena (mid-2030s): Commercial-scale laser fusion power plant designed for continuous grid-scale electricity generation.
For photos of Phoenix and the team, visit our media page.
About Xcimer Energy Inc.
Xcimer combines novel laser technology with proven science to commercialize laser fusion energy. Founded in 2022 and based in Denver, Colorado, Xcimer is backed by the world’s leading energy and technology investors and has been selected for funding by the U.S. Department of Energy. Its mission is to develop a source of affordable, safe and reliable energy. To learn more, visit https://xcimer.energy/.
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