Artificial and engineered materials are enabling new ways to control linear and nonlinear light–matter interactions. Among them, epsilon-near-zero (ENZ) materials are especially promising, as their near-zero permittivity can strongly enhance local fields and amplify nonlinear and quantum optical effects at deeply subwavelength scales. ENZ responses can be achieved in transparent conducting oxides, metamaterials and tunable organic or polymeric platforms, which offer flexibility, low-cost fabrication and dynamic reconfigurability. Ultrafast modulation further enables time-varying photonics, including frequency conversion, temporal refraction and photon acceleration. These properties make ENZ materials attractive for compact active and nonlinear devices such as optical switches, bistable systems, frequency mixers and harmonic generators.

Solid understanding of nonlinear optical phenomena at the nanoscale is the first, necessary step toward the design and development of reconfigurable devices based on nanostructures. Design principles based solely on the linear properties of nanostructures lead to the realization of static functionalities. The next and natural progress is to provide fast (nanosecond or less), inertial-less (no moving parts), and reliable tunability to these functionalities. This can be achieved by exploiting the nonlinear properties of nanostructures, whose signature can be modulated by varying physical parameters like light intensity, temperature, etc. and may also provide important information about the surrounding environment. Areas of interest include: nanoantennas for nanomixers, ultrafast nonlinearities with ultrathin nanostructures, optical limiting for laser eye protection, all-optical switches, all-optical beam steering, bistable nanoscale devices, computational electromagnetics and modeling techniques for nanostructures like metamaterials and metasurfaces.

Microwave-assisted processing offers a promising route for the sustainable recovery of lithium and other critical metals from the black mass of spent batteries. Selective electromagnetic energy deposition can provide rapid and volumetric heating, potentially reducing processing times and energy consumption compared with conventional thermal treatments. The research focuses on multiphysics modeling of microwave–material interactions, combining electromagnetic, thermal and reaction-related phenomena. Numerical simulations are used to study field distribution, power absorption and temperature evolution within heterogeneous battery materials, as well as to identify possible hot spots and non-uniform heating. The optimization of irradiation power, exposure time and reactor configuration supports efficient chemical conversion and metal recovery while limiting energy losses and unwanted thermal effects.