STRONG COUPLING IN ALL-POLYMER PLANAR MICROCAVITIES

In this work, strong coupling effect is observed in all-polymer planar microcavities incorporating TDBC J-aggregates dispersed into polyvinyl alcohol in the cavity layer. Angle-resolved polarized-light transmittance and reflectance spectra clearly reveal the characteristic anti-crossing between the excitonic transition and the microcavity optical mode, giving rise to a polaritonic state with a Rabi splitting of about 40 meV. This observation is confirmed by comparing the linewidths of the cavity mode and the excitonic transition to the Rabi splitting as well as investigating the dielectric contrast (n) provided by the polymers used in the mirrors encapsulating the cavity. Indeed, using a high dielectric contrast polymer pair (Aquivion:poly(N-vinylcarbazole), n ~ 0.33) enables clear Rabi splitting detection, while substituting Aquivion with higher refractive index cellulose acetate (n ~ 0.21) to decrease the contrast does not, highlighting the crucial role of selecting polymers with suitable n to ensure suitable optical confinement. Because polymer systems are widely recognized for their mechanical flexibility and straightforward large-area fabrication, demonstrating strong coupling in all-polymer microcavities underscores the technological significance of the results presented in this work.