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Neuromorphic models are proving capable of performing complex machine learning tasks, overcoming the structural limitations imposed by software systems and electronic neuromorphic models. Unlike computers, the brain uses a unified geometry whereby memory and computation occur in the same physical location. The neuromorphic approach tries to reproduce the functional blocks of biological neural networks. In the photonics field, one possible and efficient way is to use integrated circuits based on soliton waveguides, ie channels self-written by light. Thanks to the nonlinearity of some crystals, propagating light can write waveguides and then can modulate them according to the information it carries. Thus, the created structures are not static but they can self-modify by varying the input information pattern. These hardware systems show a neuroplasticity which is very close to the one which characterize the brain functioning. The solitonic neuromorphic paradigm this work introduces is based on X-junction solitonic neurons as the fundamental elements for complex neural networks. These solitonic units are able to learn information both in supervised and unsupervised ways by unbalancing the X-junction. The storage of information coincides with the evolution of structure that changes plastically. Thus, complex solitonic networks can store information as propagation trajectories and use them for reasoning.

We present narrow-band polarization-sensitive reflectance of GaN/AlGaN heterostructures in the mid-infrared range. Experimental measurements performed at 15° angle of incidence show the excitation of a Berreman mode at the interface between GaN and sapphire substrate. A transfer matrix method for anisotropic layers has been used to analyze the obtained results. The contribution of the two-dimensional electron gas at the interfaces of the heterostructures has been included by proper modelization of an effective thin layer.

This research introduces a novel highly efficient method to interconnect two metallic nanostrips that support the propagation of surface plasmon polariton (SPP) waves exploiting photorefractive soliton guide. The intricate design of the multilayer geometry enables light control diffraction at the metallic nanostrip’s end and reduces its angular dispersion. Moreover, the system’s on/off state can be switched by exploiting the epsilon near zero properties of the indium tin oxide (ITO) layer. The photorefractive crystal positioned between the two plasmonic waveguides enables the self-confinement of light, generating a waveguide that can be utilized by both the writing light and other wavelengths transmitted as signals. The resulting SPP waves can be efficiently recoupled in the second nanostrip, with an efficiency of around 40% across a broad range of wavelengths. This cutting-edge approach paves the way for significant advancements in the field of nanophotonics and provides a fundamental framework for the development of new, highly efficient optical interconnects in nanoscale systems. The findings of this study have implications for a wide range of applications, including nanoscale sensing, optical computing, and data communication.

In recent years, the technological revolution has changed the way we see reality and interact with it. Inevitably, education and didactic planning have also had to deal with new technologies. Indeed, the presence of digital tools has radically changed people's lives since childhood. Many educational realities have exploited this digital transformation to speed up and specialize learning, customizing study plans and type of software according to age groups. The activity of the Digital Education Lab is part of this context. It is a digital education school which uses the game software "Minecraft Education Edition" to teach its students the fundamental principles of computer science, geometry and mathematics. This article discusses learning key science concepts through game learning. The analysis carried out allows to see that students are facilitated in learning complex scientific concepts when these are shown through the game and can therefore be "experienced". The learning of 186 students aged between 8 and 10, who are generally at the first approaches to the digital world, has been evaluated. To evaluate the acquisition of knowledge through these innovative methods, at the end of the didactic course we have administered anonymous tests through the Google classroom platform. The results show that learning through a game-software facilitates the learning of basic scientific information as well as fostering the capacity for interconnection and transversality.

This publisher's note contains a correction to Opt. Lett.48, 6508 (2023)10.1364/OL.506249.