Dielectric Materials for IR applications

Single, double and multi-layered dielectric structures based on CaF2 and ZnS are deposited by thermal evaporation with thickness from few tens of nanometers up to several microns.

CaF2 and ZnS dielectrics materials are very attractive for advanced optical applications in the infrared regime, owing their quite different refractive index of 2.3 and 1.4, respectively.

For example, suitably designed periodic thin-film structures with alternating high/low refractive indices can operate as a 1D photonic crystal (1DPC) with a forbidden frequency gap of light propagation. The introduction of a “defect” layer located at the 1DPC-continuous medium interface produces Bloch Surface Waves, i.e. surface electromagnetic waves with very low intrinsic losses existing in both in-plane and out-of plane polarizations, supported by a one-dimensional photonic crystal with an in-gap defect.


Marialilia Pea                 marialilia.pea@cnr.it

Andrea Notargiacomo   andrea.notargiacomo@cnr.it