Nuclear Fusion: Xcimer Energy Launches 'Phoenix,' World's Largest Private Laser System
On June 3, 2026, Denver-based nuclear fusion startup Xcimer Energy announced the start of operations for Phoenix, the largest privately owned laser system in the world. Phoenix is designed as a prototype system to validate Xcimer's unconventional, industrial-scale laser fusion architecture, marking a major technical milestone on the path to commercial fusion energy.
Unconventional Gas Laser Architecture
In 2022, the National Ignition Facility (NIF) demonstrated net energy gain using laser-driven inertial confinement fusion. However, NIF's solid-state glass laser architecture—relying on 192 complex beamlines—is widely considered too expensive, complex, and maintenance-intensive for economical, grid-scale commercial electricity generation.
Xcimer’s alternative architecture is designed to dramatically reduce cost and complexity:
- Krypton Fluoride (KrF) Excimer Laser: Phoenix utilizes a gaseous krypton fluoride excimer laser system. This design is highly efficient, has low thermal stress, and is compatible with industrial-scale manufacturing.
- Stimulated Brillouin Scattering (SBS): Phoenix uses a 38-meter-long SBS gas optic core to compress a microsecond-long pulse into the nanosecond timescales required for fusion. This represents the highest-ever energy and largest spatial extent of SBS in an optical system.
- Simplified Beam Design: Xcimer's commercial architecture is designed to use just two beamlines rather than NIF's 192, greatly reducing operational complexity.
Rebuilding Lost Cold War Expertise
Designing and constructing Phoenix required Xcimer to rebuild specialized industrial capabilities around large-scale electron-beam-pumped excimer lasers—a competence that the United States largely abandoned after the Cold War. Supported by venture investors and funding from the U.S. Department of Energy, Xcimer spent four years recruiting engineers, physicists, pulsed-power specialists, and technicians from national laboratories, the U.S. Navy, and past government excimer laser programs.
Commercial Roadmap
Phoenix represents the first step in Xcimer's multi-stage commercialization roadmap:
- Anvil (2028): A commercial-scale excimer amplifier designed to deliver 200 kilojoules on target in a complete two-sided beamline.
- Vulcan (early 2030s): A 4-to-12 megajoule laser system targeting wall-plug breakeven. Xcimer expects to select a construction site for Vulcan in 2026.
- Athena (mid-2030s): A commercial-scale laser fusion power plant designed for continuous grid-scale electricity generation.