In China, a compact solid-state laser was developed to access the previously unreachable VUV range, opening new possibilities in scientific research, space technologies, and chip manufacturing

Chinese scientists have discovered a compact source of vacuum-ultraviolet (VUV) light

Scientists from the Xinjiang Institute of Physics and Chemistry at the Chinese Academy of Sciences have developed a new nonlinear optical crystal, ABF (NH₄B₄O₆F). This material enables the creation of a solid-state laser operating in the VUV range, which previously required large and expensive synchrotron or plasma facilities.

What’s new?
* Wavelength – 158.9 nm (the shortest result for a solid-state laser).

* Pulse energy – up to 4.8 µJ at 177.3 nm.

* Peak conversion efficiency – 7.9 %.

* Size – desktop device; does not require huge vacuum chambers.

How it works?
The ABF crystal combines:

1. High transparency in the VUV range.
2. A strong nonlinear coefficient that allows efficient frequency doubling (second harmonic).
3. Sufficient refractive index for phase matching.

As a result, scientists were able to produce a powerful, short-wavelength laser without using toxic substances (such as beryllium in KBBF) and bulky setups.

Why it matters?
* Compactness and cost-effectiveness – the solid-state design reduces manufacturing and maintenance costs.
* Reliability – longer lifespan compared with gas excimer lasers.
* Wide range of applications:
* ultra-precise material etching,
* lithography and semiconductor quality control,
* quantum computing,
* superconducting spectroscopy,
* chemical reaction studies,
* space technologies.

Brief history
For more than a decade, Chinese scientists have worked on this material. Their discovery was published in the latest issue of Nature. At that time, ASML was attempting to create a plasma laser at 158 nm but abandoned the project after many years of research.

The ABF crystal opens new possibilities for accessible and powerful VUV lasers, making them practical both in scientific laboratories and industry.