Polarization‐Controlled Strong Light–Matter Interaction With Templated Molecular Aggregates

Strong light‐matter interaction is demonstrated for a layer of templated merocyanine molecules in a planar microcavity. Using a single layer of graphene nanoribbons as a templating layer, an aligned layer of aggregated molecules is obtained. The molecular layer displays anisotropic optical properties resembling those of a biaxial crystal. The anisotropic excitonic component in the cavity results in strongly polarization‐dependent light‐matter interaction and in increased Rabi‐energies. The increased light‐matter interaction is possibly due to reduced molecular disorder in the templated molecular layer. This conclusion is supported by an analysis based on a multi‐oscillator model. Photoluminescence microspectroscopy is further used to demonstrate that the light‐matter coupling is spatially homogeneous. This study introduces molecular templating to strong light‐matter studies. The reduced disorder of the system as a consequence of templating is highly beneficial for engineering light‐matter interaction.