Abstract: Interest in Artificial Neural Networks (ANNs) has surged in recent years due to their remarkable versatility in addressing a wide range of complex problems. Today, ANNs are predominantly implemented on electronic platforms. While very-large-scale ANN models have been developed that surpass human performance in specific tasks, they do so at the cost of long training times and significant power consumption. A promising alternative lies in Photonic Neural Networks (PNNs), which leverage the inherent advantages of photonics—namely, high-speed processing, massively parallel transmission (enabled by Wavelength Division Multiplexing, WDM), and low power dissipation. This seminar will explore a series of simple PNN prototypes implemented on a silicon photonics platform, illustrating the fundamental operating principles of silicon-based PNNs. Silicon photonics is particularly attractive due to its compatibility with electronic integration, enabling on-chip training and scalable fabrication of photonic circuits. A key example to be discussed is a basic optical neuron, in which multiple delayed versions of an optical input signal interfere before reaching the output port—demonstrating an essential mechanism for computation in photonic networks. Finally, the hybrid approach that combines photonic neural networks with biological neurons will be discussed. It enables experiments in which optical signals are transduced into neuronal activity, activating specific neural circuits. This integration paves the way toward hybrid intelligence systems, opening new frontiers in neuromorphic computing and advanced neurological therapies.

Bio: Lorenzo Pavesi is a Professor of Experimental Physics in the Department of Physics at the University of Trento, Italy. He earned his PhD in Physics from the École Polytechnique Fédérale de Lausanne (Switzerland) in 1990. That same year, he joined the University of Trento, where he initiated several research activities and established laboratories focused on photonics, material growth, and advanced material processing. Currently, Prof. Pavesi leads the Nanoscience Laboratory, a multi-investigator research center at the University of Trento. He has served as Head of the Department of Physics, Founding Director of the joint laboratory Quantum at Trento (Q@TN), and Founding President of the IEEE Italy Chapter on Nanotechnology.

In recognition of his scientific achievements, Prof. Pavesi was awarded the title of Cavaliere by the President of the Italian Republic in 2001. He was named a Distinguished Lecturer by the IEEE Photonics Society in both 2010 and 2011. He is currently an ERC grant recipient and a Fellow of the IEEE, SPIE, AAIA, and the Italian Physical Society (SIF). Prof. Pavesi has authored over 500 scientific publications and reviews, edited more than 15 books, authored two books, and holds nine patents. He has supervised 42 PhD students and over 48 Master's theses. A pioneer of silicon photonics, his research focuses on the optical properties of semiconductors, aiming at the convergence of photonics and electronics. His work explores active photonic devices that leverage optical nonlinearities and material engineering. His broad scientific interests include optical and biosensing technologies, solar energy conversion devices, and emerging fields such as integrated quantum photonics and neuromorphic photonics.