A Colorado Company Just Built a Laser Fusion Machine That Hasn't Been Made in 20 Years

Xcimer Energy, based in Denver, has finished building a special laser that scientists have been trying to develop for decades. It's the first one of its kind made by a private company, and the first one anyone has built in more than 20 years. In May 2024, their machine produced a laser pulse that lasted longer than any previous attempt, hitting a record that opens a new chapter in the quest for fusion energy — a type of power generation that could theoretically provide nearly unlimited clean electricity.

The company is working toward a goal set by the U.S. Department of Energy to speed up the development of commercial fusion energy. This laser system is one of several stepping stones on their path from today's experimental machines to a functioning power plant that could feed electricity into the grid.

What This Laser Does

Xcimer's laser works by firing extremely brief, intense pulses of light at a target filled with special gases. Think of it like using a microscopic spotlight to squeeze fuel so hard and fast that it triggers the same nuclear reaction that powers the sun — fusion.

The laser uses two types of gas mixtures, operating at wavelengths (colors of light) that are invisible to the human eye. The pulses last between one ten-millionth of a second and three millionths of a second, delivering intense energy in a tightly focused spot. This is extraordinarily precise work: the laser must be strong enough and controlled enough to compress fuel pellets to extreme density in a fraction of a heartbeat.

The design builds on work that government laboratories — particularly the Naval Research Laboratory and Lawrence Livermore National Laboratory — have been developing for decades. Xcimer is taking those research results and turning them into something that could actually work at commercial scale.

The company plans to build a larger test machine in Denver, then move on to an even bigger demonstration system. Eventually, they aim to construct what they're calling Athena — their vision of the world's first laser fusion power plant.

Money and Team

Xcimer raised 100 million dollars in funding from a group of investors who specialize in long-term, high-risk technology bets. The Department of Energy is also providing funding through a program that pays companies when they hit specific technical milestones — essentially paying for results rather than just handing over money up front.

The company has been hiring experienced engineers and managers to expand its team. They plan to double the number of people working there over the next year as they move toward building their prototype.

Why This Matters Now

The broader context here is that for most of the past two decades, fusion energy felt like a distant dream. Government laboratories kept the research alive, but private companies stayed away — it seemed too hard and too far off. In the last few years, that has shifted. Several companies are now racing to build working fusion reactors, and the U.S. government is pushing hard to make it happen by the mid-2030s.

Xcimer is one of roughly eight companies receiving this kind of milestone-based funding from the government. They are taking a laser-based approach, which differs from other companies like Commonwealth Fusion Systems, which are using a different technique called magnetic confinement. Both approaches could potentially work — we don't yet know which one will prove more practical and cost-effective.

The fact that Xcimer was able to build this laser at all, and do it in the private sector, carries real significance. The 20-year gap since anyone last built one of these machines tells you something: the technology is genuinely hard, and it was not commercially interesting until recently. Now that fusion has become a serious investment focus, Xcimer is validating that the knowledge exists to build these machines outside of government laboratories.

The Long Road Ahead

It is worth noting that a working laser in the lab and an actual power plant delivering electricity to homes are very different things. Xcimer still faces major engineering challenges: making the whole system efficient enough that it produces more energy than it uses, building it reliably so it runs day after day without breaking down, and making it affordable enough to compete with other clean energy sources like solar and wind.

The mid-2030s timeline the company is working toward is an ambitious target. Even if Xcimer hits every milestone on schedule, actually connecting a fusion power plant to the grid involves regulatory approval, grid integration work, and proving that the economics pencil out. Many deep-tech companies have hit technical milestones only to discover that commercial viability is a different hurdle altogether.

That said, the combination of government validation, serious private investment, and a working prototype puts Xcimer in a credible position in the race toward commercial fusion. What they've done so far is real progress — not a guaranteed path to success, but the kind of progress that makes the leap from lab to power plant feel less like science fiction and more like engineering.