Inertial fusion startup Xcimer Energy has completed an electron-beam-pumped excimer laser. According to the company, this is the first laser of its kind funded by the private sector, and the first built by any organization in more than 20 years. The system operates at the longest pulse length of any Krypton Fluoride (KrF) laser, the company added. And last month, according to a press release from the company, the laser achieved a pulse length of 3 μs, a global record for this type of laser source. Xcimer’s Long Pulse Kinetics (LPK) platform is the first key element of its prototype laser system, code-named Phoenix, which is on track to be completed in 2026. The LPK collects data that proves the viability of Xcimer’s technology and informs future design of its lasers that will power inertial fusion energy systems. Xcimer Energy’s newly minted electron-beam-pumped excimer laser is reportedly the first of its kind built by the private sector, and the first built by any organization in more than 20 years. Courtesy of Xcimer Energy/Edward DeCroce. Xcimer submitted a report on its LPK system to the U.S. Department of Energy’s Milestone-Based Fusion Development Program. Completion and operation of the LPK represents Xcimer’s first major technical milestone in the program. “We’ve already begun using Xcimer’s LPK experimental testbed to validate laser models and inform the design of our future systems,” said Conner Galloway, CEO and chief science officer of Xcimer. “This milestone also sends the strongest signal yet that the private sector can build on decades of public investment to turn transformative research into commercially viable systems. We’ve seen this transition before in industries like space — and we’re beginning to see it happen in fusion.” Following the completion of the LPK platform, Xcimer aims to wrap construction on its next-generation facility, called Vulcan. The company is targeting 2030 for the project’s completion and has begun taking proposals for prospective sites. Last year, Xcimer raised $100 million in a series A financing round. The company was selected for a $9 million award in 2023 from the U.S. Department of Energy’s (DOE) Milestone-Based Fusion Development Program. Xcimer is also involved in the DOE’s three inertial fusion energy hubs in the Inertial Fusion Energy Science and Technology Accelerated Research (IFE-STAR) initiative, consisting of public and private organizations and government research labs.