Femtosecond response of J aggregates adsorbed onto silver colloid surfaces

The observation of stimulated emission from J aggregates adsorbed onto silver colloid surfaces using femtosecond excitation was reported. The stimulated emission was inferred from the excitation intensity and wavelength dependence of the emission band. The stimulated emission originated from the amplification of the one-exciton state emission by an induced transition from the two-exciton state to the one-exciton state