Researchers from the University of Amsterdam’s Institute of Physics, led by Jorik van de Groep, have developed a groundbreaking method to detect image edges with exceptional speed and minimal energy consumption. Their findings were recently published in ACS Photonics

Computing With Light

As the demand for computing power continues to grow, energy consumption has become a major concern. Traditional hardware struggles to keep up with increasing software demands, making energy-efficient alternatives a pressing need. In response, researchers have been exploring new computing methods that offer high-speed performance with lower energy requirements.

One promising approach is optical analog computing, a technique that uses light to perform mathematical operations before the image is even captured by a camera. Optical analog computing devices do not require electrical power, making them incredibly energy-efficient. Additionally, because these operations occur at the speed of light, the process is almost instantaneous.

This breakthrough could pave the way for more efficient and faster data processing solutions, offering a potential game-changer for industries reliant on high-speed imaging and analysis.

Breakthrough in Edge Detection

In their research, together with industrial partners WITec and SCIL Imprint Solutions, the physicists have focused on edge detection techniques, aimed at identifying edges in images – locations where a sudden change in brightness occurs, indicating the border of an object that is observed. Edge detection is one of the most crucial tasks in image processing with applications in e.g. autonomous vehicles. To perform the optical analog computing, the physicists used a simple and easy-to-fabricate stack of thin films.

The method turned out to work very well, being able to detect the edges of even very small objects, about 1 micrometer in size.

Bernardo Dias, first author of the publication, says: “The design of the layer stack is extremely simple compared to the complex optical coatings that pose as the state-of-the-art. Despite this, our device shows one of the largest numerical apertures to date, allowing us to perform edge detection on the smallest possible targets.”

Enhancing Microscopic Imaging

An additional benefit of the method is that it can work with a large number of light sources like lamps, LEDs, or lasers, facilitating its potential use in existing technology. The results demonstrate that these techniques can in particular be used for high-resolution microscopy. Since the device also highlights the edges of transparent objects which would be invisible to a conventional bright field microscope – think of cells – application in biological samples is also possible.

As a next step, the researchers aim to develop switchable devices for optical analog computing, where one can switch the mathematical operation on and off, or where the device can switch between different functions.

Reference: “High-NA 2D Image Edge Detection Using Tamm Plasmon Polaritons in Few-Layer Stratified Media” by Bernardo S. Dias and Jorik van de Groep, 2 December 2024, ACS Photonics.
DOI: 10.1021/acsphotonics.4c01667