strong Light-matter c oupling Using a Robust non-cyanine Dye J-aggregate Material

We demonstrate strong light-matter coupling using a promising new J-aggregatematerial based on a dibenz[a, j]anthracenemacrocycle [1], Figure 1a, that is robust under high power optical excitation. Strong light-matter coupling leads to polaritonicresonances that are superpositions of the underlying excitonicand photonic states [2] and can exhibit laser-like coherent light emission at remarkably low excitation densities due to polaritoncondensation [3]. A key hindrance to achieving polaritoncondensation thus far using cyaninedye J-aggregateshas been exciton-exciton annihilation[4], which quenches excitations from the polaritonicstates before they can condense. The J-aggregatesof the dibenz[a, j]anthracene-based macrocycle show no signs of exciton-exciton annihilationuntil optical excitation densities exceeding 20 MW/cm