Physicists at ETH Zurich have developed a breakthrough ultra-thin lens that can make invisible infrared light visible—potentially transforming everything from smartphones to security systems and scientific tools.
Key Points at a Glance
- ETH Zurich creates first lithium niobate metalens to convert infrared into visible light
- New technique uses nanoimprinting to produce cost-effective, scalable metasurfaces
- Lens halves wavelength of light, enabling visible detection of infrared radiation
- Applications range from anti-counterfeit security to deep-UV microchip fabrication
- Innovation bridges physics, chemistry, and materials science
In a landmark optical innovation, researchers from ETH Zurich have built an ultra-thin metalens capable of a kind of scientific magic: making invisible infrared light visible to the human eye. At the heart of the discovery lies a marriage of advanced materials and nanotechnology—yielding a new generation of ultra-compact optical devices with revolutionary potential.
Led by Professor Rachel Grange at ETH Zurich’s Institute for Quantum Electronics, the team developed a method to fabricate lenses from lithium niobate—a material prized for its nonlinear optical properties but notoriously difficult to miniaturize. By imprinting nanostructures just hundreds of nanometers wide onto a substrate using a technique akin to Gutenberg’s printing press, the researchers succeeded in shaping a metalens that both focuses light and converts its wavelength.
The result is a lens thinner than a strand of human hair that takes incoming infrared light at 800 nanometers and outputs focused visible light at 400 nanometers. The nonlinear optical process at work here mirrors that used in green laser pens, but is integrated directly into an ultra-flat optical element. Crucially, the effect is not limited to a single wavelength, making the lens versatile across applications.
This advance is not just about compact optics—it’s about what those optics can do. Metalenses like this one can make infrared sensors visible to standard cameras, reduce the hardware needed in chip manufacturing, or even bring new resolution to microscopic imaging systems. Because of their structure and material properties, such lenses could also serve as security features that are impossible to replicate with conventional tools—ideal for safeguarding banknotes, artworks, or digital devices against counterfeiting.
Until now, lithium niobate was considered too hard and stable to shape into such small-scale structures. But by printing it in liquid form and heat-curing it at 600°C, Grange’s team has created a scalable, cost-effective process that could open the door to mass production. The nanostructures that emerge can be reproduced repeatedly using inverse molds, dramatically cutting down on time and manufacturing costs.
“We have only scratched the surface,” said Grange, noting that this new branch of research—called metasurfaces—sits at the frontier of materials science, physics, and chemistry. The implications extend far beyond the lab. Future applications may include wearable sensors, integrated photonic chips, augmented reality displays, and much more.
As electronic devices shrink and demands for optical performance rise, breakthroughs like these could eliminate the bulky lens stacks still found in even the most advanced smartphones. The new metalens offers a pathway not only to see more clearly—but to see the invisible.
Source: ETH Zurich
