Optical constants modelling in silicon nitride membrane transiently excited by EUV radiation

R. Mincigrucci, D. Naumenko, L. Foglia, I. Nikolov, E. Pedersoli, E. Principi, A. Simoncig, M. Kiskinova, C. Masciovecchio, F. Bencivenga, F. Capotondi

Research output: Contribution to journalArticlepeer-review


We hereby report on a set of transient optical reflectivity and transmissivity measurements performed on silicon nitride thin membranes excited by extreme ultraviolet (EUV) radiation from a free electron laser (FEL). Experimental data were acquired as a function of the membrane thickness, FEL fluence and probe polarization. The time dependence of the refractive index, retrieved using Jones matrix formalism, encodes the dynamics of electron and lattice excitation following the FEL interaction. The observed dynamics are interpreted in the framework of a two temperature model, which permits to extract the relevant time scales and magnitudes of the processes. We also found that in order to explain the experimental data thermo-optical e ects and inter-band filling must be phenomenologically added to the model.

Original languageEnglish
Pages (from-to)11877-11888
Number of pages12
JournalOptics Express
Issue number9
Publication statusPublished - 30 Apr 2018
Externally publishedYes

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

Cite this