For more than two hundred years, cameras have steadily evolved from bulky contraptions into essential tools of daily life.
Today, they are everywhere—built into smartphones, laptops, cars, drones, satellites, and even medical instruments.
But as technology keeps shrinking, researchers face a big challenge: how to design smaller, lighter, and more energy-efficient cameras without sacrificing image quality.
One promising idea has been the use of ultra-flat optics, or metalenses. Unlike traditional curved glass or plastic lenses, metalenses are made of thin layers covered in tiny nanostructures that bend light.
Because of their design, they can be hundreds or even thousands of times thinner and lighter than standard lenses.
In theory, this makes them perfect for compact devices like smartphones or satellites, where saving space and weight matters.
The problem, however, has been image distortion. Metalenses struggle with a common optical flaw known as chromatic aberration, where different colors of light fail to come into focus at the same point.
This problem gets worse as the aperture—the opening that lets light into the camera—gets bigger. For years, scientists assumed this was an unbreakable limitation. Large-aperture metalenses could not, it was believed, produce sharp, full-color images.
A research team from the University of Washington (UW) and Princeton University has now proven otherwise.
In a first-of-its-kind study published in Nature Communications, the team demonstrated that a camera equipped with a large-aperture metalens can capture high-quality color images and video comparable to those made with a traditional lens.
This achievement not only overturns a long-standing assumption in optics but also opens new possibilities for miniaturized imaging systems.
The new lens is just one micron thick. Even when mounted on a supporting base, the whole system measures only 300 microns across—roughly the width of four human hairs. Compared to a conventional refractive lens, it is hundreds of times thinner.
Such a drastic reduction in size and weight could lead to significant savings in battery life and space across a wide range of devices.
Smartphones and laptops are obvious first applications, but the benefits extend far beyond personal electronics.
Drones, satellites, and cars could all benefit from lighter imaging systems. In medicine, smaller and thinner lenses could make endoscopes or angioscopes less invasive and more effective, helping doctors peer deeper into the human body.
So how did the researchers beat the chromatic limitation? Their secret was treating the problem as a combined challenge of optics and computation. Instead of relying solely on physics-based lens design, the team used artificial intelligence to co-optimize both the hardware and the computational “backend” that processes images.
The AI system, a neural network, takes raw optical data and reconstructs sharper, more colorful images with reduced noise and haze. This joint approach allowed the researchers to produce clear images even with a lens aperture much larger than previously thought possible.
“Previously, it was assumed that the larger the metalens is, the fewer the colors there are that can be focused,” said lead author Johannes Fröch of UW. “But we went beyond that and beat the limit.”
The researchers see enormous potential ahead. They plan to refine image quality further and explore applications that go beyond visible light, such as polarization or infrared imaging—techniques already used in LiDAR for self-driving cars and augmented reality.
They are also exploring commercialization, since metalenses can be mass-produced with nanoprint lithography, making them affordable for everyday devices.
The project highlights a shift in how optics are designed, blending physics and computation in ways that seemed impossible only a few years ago. “Our work shows what can be done with ultra-flat optics,” Fröch said. “We’ve pushed the field forward, and this is only the beginning.”
