Expert Profile：

Sebastian Volz has been developing direct simulations and characterizations to understand heat in solids at the carrier's level. His group was involved in large european projects on thermoelectricity and thermal interface materials, he has also operated a key project from the japanese agency JST on thermal management in microsystems. Sebastian Volz has led the european Thermal NanoSciences and NanoEngineering CNRS network (2001-2018) and the CNRS-UTokyo joint Laboratory for Integrated Micro-Mechatronic Systems (2018-2025). He is now the director of the joint Laboratoire des Solides Irradiés of CNRS, Ecole Polytechnique and CEA.

Title of Presentation：

Polariton activated radiation of guided modes

Please choose one Forum Theme：

G. Non-Conductive Heat Transport (convection, radiation, etc.)

Abstract：

Over the two past decades, substantial research efforts have been devoted to the study of surface phonon polariton modes, especially due to their ability to transfer an exalted heat flux through submicron gaps. Surface polaritons are essentially evanescent waves in the out-of-plane direction but propagate along the surface of polar dielectrics.

More recently, it has been theoretically proposed that polaritons could also carry an in-plane heat flux, especially in thin films, where those modes cover a large spectrum and have extremely long propagation lengths. Theoretical models predicted that such propagation lengths enable a larger heat conduction via polaritons than via phonons.

In this seminar, the existence and the properties of those film-polaritons will be demonstrated then the experimental measurement of the corresponding heat flux will be presented. Our recent theoretical investigations confirm the match between measurements and predictions within 5% of inaccuracy.

Further measurements investigating thermal radiation of films beyond the reactive near-field will be also introduced.