EX-Fusion Inc., an Osaka University spinoff, is Japan's first startup pursuing commercial laser-based (inertial confinement) fusion energy — a fundamentally different approach from the tokamak magnetic confinement pursued by ITER and Fujitsu/RIKEN. In July 2025, EX-Fusion and Hamamatsu Photonics achieved a world first: continuous irradiation of simulant fuel targets using high-power pulsed lasers for one hour — demonstrating the repetitive laser firing capability essential for a power plant that would need to compress fuel pellets 10+ times per second. Hamamatsu is the only private company globally possessing laser-diode-pumped technology at the power levels required.
Laser fusion gained credibility after the US National Ignition Facility achieved fusion ignition in December 2022 using 192 laser beams. EX-Fusion's approach builds on Osaka University's Institute of Laser Engineering (ILE), which operates the GEKKO-XII and LFEX lasers and has decades of laser fusion research. The company raised $13 million in seed funding and secured investment from JX Advanced Metals (rare metals company) in 2025, signaling industrial interest beyond pure research. Hamamatsu was admitted to an international fusion commercialization working group in October 2025.
Japan's laser fusion bet leverages a genuine national strength: Hamamatsu's unmatched laser and photonics technology, Osaka University's world-class laser fusion research, and Japan's broader precision optics industry. While commercial laser fusion is likely decades away, the intermediate applications of high-power laser technology — industrial cutting, material processing, medical devices, and defense — create near-term value. Japan pursuing both tokamak (JT-60SA) and inertial confinement fusion hedges its bets on which approach ultimately proves commercially viable.