Ricerc@Sapienza

This Project aims at both theoretical and experimental investigation of polar metasurfaces and metamaterials for managing of surface phonon polaritons (SPhPs). The development of a photonic platform in the mid-infrared (MIR) range is an active field of research motivated by applications, such as detection of traces of biomolecules and harmful/explosive substances, passive radiative cooling as well as devices for thermal imaging and for medical diagnostics.
Most of the advances in this field have been achieved by excitation of SPPs supported by doped semiconductors or in graphene. Our approach is based on the exploitation of different polaritonic modes called surface phonon polaritons (SPhPs) in van der Waals (vdW) materials and in polar materials based on their nanostructuration with randomly dispersed subwavelength dielectric elements.
Different materials will be exploited, such as innovative and extremely promising 2D vdW materials as hexagonal boron nitride (hBN) and molybdenum trioxide (MoO3), displaying multiple Reststrhalen bands along two (hBN) or three different (MoO3) crystallographic directions. Dynamic control of surface phonon polaritons (SPhPs) resonances will be also investigated by adding a layer of thermochromic vanadium dioxide, VO2. Finally, more insight into materials crystalline structure and further resonances tunability will be achieved using optical second harmonic generation nonlinear optical effects.
This proposal addressing key challenges in mid-IR polaritonic platforms involves several novel and creative ideas that will push the field forward and highly benefit the scientific community. In particular use of polar oxides for controllable, tunable and flexible mid-IR polaritonic metamaterial and metastructure platforms are poised to play significant role in advancement of key application areas including biosensing, novel IR photonic components (filters, polarizers, emitters, switches).