The Solitonic X-Junction as a Photonic Neuron

This chapter describes in detail the physics behind the formation of photorefractive spatial solitons, taking care also of the mathematical aspects. Starting with a description of single soliton formation, the X-Junction solitonic neuron is introduced from both theoretical and experimental perspectives. Experiments on the neuron writing process and selectively erasing the soliton channels of which it is composed are presented. The fabrication of a solitonic neuron in an 8-micron thin film of lithium niobate on insulator, an extremely promising technology nowadays, is also described.