%0 Journal Article
%T Strong Coupling of Exciton-Polaritons in a Bulk GaN Planar Waveguide: Quantifying the Coupling Strength
%+ Laboratoire Charles Coulomb (L2C)
%A Brimont, Christelle
%A Doyennette, Laetitia
%A Kreyder, G.
%A Reveret, F.
%A Disseix, P.
%A Medard, F.
%A Leymarie, J.
%A Cambril, E.
%A Bouchoule, S.
%A Gromovyi, M.
%A Alloing, B.
%A Rennesson, S.
%A Semond, F.
%A Zuniga-Perez, J.
%A Guillet, Thierry
%< avec comité de lecture
%Z L2C:20-164
%@ 2331-7019
%J Physical Review Applied
%I American Physical Society
%V 14
%N 5
%P 4060
%8 2020-11-23
%D 2020
%R 10.1103/physrevapplied.14.054060
%Z Physics [physics]/Condensed Matter [cond-mat]Journal articles
%X We investigate the demonstration and quantification of the strong coupling between excitons and guided photons in a GaN slab waveguide. The dispersions of waveguide polaritons are measured from T = 6 to 300 K through gratings. They are carefully analyzed within four models based on different assumptions, in order to assess the strong-coupling regime. We prove that the guided photons and excitons are strongly coupled at all investigated temperatures, with a small (11%) dependence on the temperature. However, the values of the Rabi splitting strongly vary among the four models: the "coupled oscillator" model overestimates the coupling; the analytical "Elliott-Tanguy" model precisely describes the dielectric susceptibility of GaN near the excitonic transition, leading to a Rabi splitting equal to 82 ± 10 meV for fundamental transverse-electric mode; the experimental ellipsometry-based model leads to smaller values of 55 ± 6 meV. We evidence that, for waveguides including active layers with large oscillator strengths, as required for room-temperature polaritonic devices, a strong bending of the modes' dispersion is not necessarily the signature of the strong coupling, which requires for its reliable assessment a precise analysis of the material dielectric susceptibility.
%G English
%2 https://hal.science/hal-03034132/document
%2 https://hal.science/hal-03034132/file/PRApplied14%282020%29054060_StrongCouplingofXPolInaBulkGaNPlanarWaveguideQuantifyingtheStrongCouplingStrength.pdf
%L hal-03034132
%U https://hal.science/hal-03034132
%~ CNRS
%~ L2C
%~ MIPS
%~ UNIV-MONTPELLIER
%~ ANR
%~ UM-2015-2021