TDK Corporation, a Japanese multinational electronics manufacturer, has announced the development of the world’s first spin photo detector capable of an ultra-high-speed response of 20 picoseconds--over ten times faster than existing semiconductor-based photo detectors.
A TDK representative told Paperjam that the company aims to begin providing samples for collaborative development with customers within one year, with full commercialisation expected within three to five years. This timeline highlights TDK’s intention to move the innovation from lab to market, paving the way for its integration into next-generation technologies.
To put that into perspective, 20 picoseconds--or twenty trillionths of a second--is so fast that light travels just 6 millimetres in that time, making the detector’s response effectively instantaneous for most high-speed applications.
Technological breakthrough
The cutting-edge device, referred to as a “photo-spintronic conversion element,” was developed in collaboration with Nihon University in Japan. It represents a significant step forward in the integration of optical, electronic and magnetic technologies.
Unlike conventional photo detectors that rely on semiconductor-based mechanisms and face limitations in terms of speed and wavelength range, TDK’s spin photo detector uses a fundamentally different approach: it leverages the heating of electrons in magnetic materials for photoelectronic conversion--that is, the process of turning light into electrical signals.
TDK also confirmed that the device functions across a wide spectrum, responding to light at wavelengths of 800 nanometres (near-infrared) and extending into the visible light range.
The spin photo detector was built upon the magnetic tunnel junction (MTJ) technology, a method already employed in billions of hard disk drive (HDD) heads. One of the key advantages of this approach is that it does not require crystal growth on a single-crystal substrate, making the technology more adaptable to a variety of materials and manufacturing environments.
Why this matters
According to TDK, the breakthrough addresses the growing demands of artificial intelligence (AI) systems, which increasingly require faster and more energy-efficient data transmission and processing. Today, data is transferred between CPUs, GPUs and memory via electrical signals--an approach that hits speed limits, particularly over longer distances.
In contrast, optical communication--using light instead of electricity--is capable of maintaining high speeds regardless of distance. TDK believes that its spin photo detector could be instrumental in enabling this shift by converting optical signals into electrical signals at unprecedented speeds, while also reducing power consumption.
This could have far-reaching implications for the design and efficiency of future AI hardware.
Broader applications
Thanks to its speed and broad-spectrum sensitivity, the spin photo detector has potential uses across both wired and wireless applications. TDK envisions it playing a key role in smart glasses, ultra-high-speed image sensors, spectroscopic analysers, generative AI and beyond 5G/6G communications. Additionally, TDK highlighted the technology’s suitability for AR/VR applications, such as augmented and virtual reality smart glasses. The use of MTJ elements--known for their resistance to cosmic rays--also makes the detector a promising candidate for space communications.