Hexium produces enriched lithium isotopes, including lithium-6 and lithium-7, using atomic vapor laser isotope separation (AVLIS) technology. Lithium-6 is supplied to fusion energy companies for tritium fuel breeding and reactor radiation shielding, while lithium-7 is provided to conventional nuclear reactor operators as a coolant additive; additional markets include medical and industrial applications. The AVLIS process vaporizes lithium metal and uses precisely tuned low-power lasers to selectively ionize target isotopes, which are then separated via an electric field and collected. The company was co-founded in 2023 by Charlie Jarrott (previously at fusion startup Focused Energy), Jacob Peterson (previously at Focused Energy), and Martin Griswold (CTO, experimental physicist specializing in laser isotope separation). Hexium emerged from stealth with $9.5 million seed funding and $2.5 million credit facility in April 2025 led by MaC Venture Capital and Refactor Ventures, with participation from Humba Ventures, Julian Capital, Overture VC, and R7 Partners; it raised an additional $13 million early-stage VC round in July 2025 for total funding of $25.1 million from investors including Climate Capital and Great Wave Ventures. Headquartered in Austin, Texas, the company employs 11-50 people focused on laser physics, plasma physics, photonics, nuclear engineering, and related hardware.