In this field of research, the sector develops techniques for the experimental and numerical investigation of the optical response (scattering, absorption) of porous or heterogeneous media at the micro and nanoscale. These media are technologically relevant for optical and thermal radiation management applications, in the field of absorption spectroscopy for gas sensing applications, as well as for fundamental interest in the properties of electromagnetic fields within nano and micro-structured media. (Objective in line with the Focal Points: Monitoring the environment and supporting the development of clean technologies, accelerating digital transformation and supporting industrial transitions, Improving the quality and impact of fundamental scientific research).