This article dives into two big advances in organic light-emitting diode (OLED) technology that might just shake up how we think about displays, imaging, and even quantum communications. Researchers at ETH Zurich have managed to shrink OLED pixels down to the nanoscale, unlocking wild resolution and optical effects. Meanwhile, a team at the University of Oxford figured out how to electrically switch the handedness of circularly polarized light from OLEDs—without needing to swap out the molecules inside.
These breakthroughs hit both the spatial and polarization control of light. Those are basically the backbone of next-gen photonic tech.
Nano-OLEDs: Shrinking Pixels to the Scale of Cells
OLEDs power our fanciest smartphones, TVs, and wearables, but their pixels have always hit a wall due to how we make them and how light works. The ETH Zurich team just blew past that wall, creating nano-OLEDs with pixel sizes around 100 nanometers.
That’s about 50 times smaller than the pixels you’ll find in even the best displays today. To really get a sense of scale, these pixels are roughly the size of a human cell and way smaller than anything your eye can pick out.
This kind of size reduction means you could cram in a pixel density up to 2,500 times higher than what’s possible now. That’s not just a small upgrade—it’s a leap.
Ultra-High-Resolution Displays for Wearables and Beyond
Packing so many tiny pixels together opens up the possibility for ultra-high-resolution screens with sharpness that feels almost unreal. In things like wearable glasses or AR headsets, every single pixel matters for how real and comfortable the experience feels, especially since the screens sit so close to your eyes.
With nano-OLEDs, designers could make displays so finely detailed that your eyes can’t spot any pixelation, even if you’re basically pressing your nose to the screen. That’s a game-changer for:
Illuminating the Nanoscale: A New Tool for Microscopy
But these tiny OLED pixels aren’t just for gadgets. Since the light-emitting spots can be squeezed into sub-micrometer regions, nano-OLEDs make fantastic, pinpoint light sources for high-resolution microscopy.
Researchers can light up tiny parts of a sample, boosting contrast and detail in optical imaging. This could be a huge deal for:
Each nano-OLED acts like a “nanoscale spotlight.” That lets scientists image or experiment in ways that just weren’t possible with traditional illumination.
Nano-OLEDs as Sensors and Building Blocks for Tiny Lasers
These nanoscale emitters are about the same size as biological cells or even smaller structures, so they can work as sensitive detectors of biological signals. If you place them near neurons or other excitable cells, nano-OLEDs might pick up on tiny changes in the environment or optical properties as cells do their thing.
Things get even more interesting when you put these pixels close together. The ETH Zurich team found that if you space pixels closer than half the wavelength of visible light—so, about 200–400 nanometers—their light waves start to interact and line up in special ways.
This lets them precisely control the direction of the emitted light. By arranging nano-OLEDs in just the right pattern, you can bundle their light into a tightly focused beam.
That’s the basic recipe for miniaturized lasers built from OLEDs—tiny, flexible, and potentially cheap devices with laser-like performance. Who saw that coming?
Electrically Switchable Circularly Polarized Light from OLEDs
While ETH Zurich zeroes in on pixel size and spatial control, the Oxford crew takes on light’s polarization—specifically, circular polarization. Circularly polarized light can be left- or right-handed, and that “handedness” can actually encode information or enable some pretty specialized optical tricks.
Making circularly polarized light from OLEDs usually means using chiral molecules, which come in two mirror-image forms. But if you want to switch between left- and right-handed light, you’d normally need both types, which is a pain to make and sort out.
A Single Molecule, Two Polarizations
The Oxford group took a totally different path. Instead of swapping out molecules, they used a single molecular form and managed to flip the polarization of the emitted light just by tweaking the electrical setup.
By adjusting how electrons and holes meet up in the OLED, they can electrically switch between left- and right-handed circularly polarized light. That means you don’t need separate chiral stuff, which makes the whole device simpler.
Plus, you can switch the polarization fast, whenever you want, right in a standard OLED structure. That’s pretty slick.
Implications for Energy Efficiency, Communications, and Quantum Tech
Having this kind of electronic control over circular polarization could really shake up a few areas:
Toward the Next Generation of Light-Driven Technologies
Researchers at ETH Zurich and the University of Oxford are pushing two big frontiers in light-based tech. They’re working on nanoscale spatial control and electrical control of polarization.
Nano-OLEDs could bring crazy-high resolution and pinpoint illumination. There’s even talk about on-chip lasers.
At the same time, being able to switch circular polarization with electricity opens up new options for displays and optical communications. That sounds like a game-changer for efficiency and data, honestly.
Wearable displays might soon look ultra-realistic, and microscopes could get a serious boost. Compact quantum optics platforms are also on the horizon.
All this? It’s rooted in the same core tech: the humble OLED, which just keeps getting more impressive.
Here is the source article for this story: ETH Zurich manufactures OLEDs at the nanoscale with ‘minute’ pixels…