Tensor operations, the mathematical heavy lifting behind AI, from image recognition to natural language processing, have become increasingly demanding. Traditional GPUs are struggling to keep pace with the exponential growth of data, creating bottlenecks in speed, scalability, and power consumption.
The Aalto University team, led by Yufeng Zhang from the Photonics Group, has introduced an ingenious method that harnesses the fundamental properties of light to perform complex tensor computations instantaneously. This approach sidesteps the step-by-step processing of conventional computers, achieving single-shot tensor computing at light speed.
Their groundbreaking research, published in Nature Photonics, details how they encode digital data into the amplitude and phase of light waves. This effectively transforms numbers into physical properties of the optical field. When these light fields interact, they naturally execute mathematical operations like matrix and tensor multiplications, which are essential for deep learning algorithms.
How it Works: A Customs Analogy
To illustrate the concept, Zhang uses a compelling analogy: “Imagine you’re a customs officer who must inspect every parcel through multiple machines with different functions and then sort them into the right bins.”
“Normally, you’d process each parcel one [at a] time. Our optical computing method merges all parcels and all machines together—we create multiple ‘optical hooks’ that connect each input to its correct output. With just one operation, one pass of light, all inspections and sorting happen instantly and in parallel.”
This parallel processing capability is a game-changer, offering a way to bypass the limitations of sequential computation.
Another key advantage lies in the simplicity of the process. The optical operations occur passively as light propagates, eliminating the need for active control or electronic switching during computation. This passive operation translates to significantly reduced energy consumption.
“This approach can be implemented on almost any optical platform,” notes Professor Zhipei Sun, leader of Aalto University’s Photonics Group. The team envisions integrating this computational framework directly onto photonic chips, creating light-based processors capable of handling complex AI tasks with minimal power consumption.
Zhang optimistically predicts that this technology will be integrated into existing hardware platforms within the next three to five years. This integration promises to usher in a new generation of optical computing systems, dramatically accelerating AI applications across diverse fields. The impact on areas ranging from drug discovery to autonomous vehicles could be transformative.

