Open Access

Saeed Nosrati, Tim RammlerORCiD, Alfred MeixnerORCiD, Frank WackenhutORCiD

• Strong coupling has attracted much research interest motivated by the possibility to tune the energy levels of molecules enabling to control and modify chemical reactions. Strong coupling leads to the formation of new hybrid modes and is caused by coherent energy exchange between the individual constituents. Such a coherent energy exchange occurs when the coupling rate exceeds the damping rate of the individual components and has been observed for highly diverse systems. Here, we present a strongly coupled hybrid system consisting of a thin TDBC J-aggregate film inside an optical subwavelength microresonator coupled to a second microresonator. This hybrid structure combines strong coupling of purely optical modes with strong light–matter interaction. The coupling strength and damping sensitively depend on the position and concentration of the coupled molecules in the microresonator structure. Such a coupled system can be modeled by coupled damped oscillators, which allows to determine the coupling and damping constants. We show that the individual components making up the coupled hybrid system cannot be treated individually, but the coupled system needs to be considered as a whole. As a consequence, altering one parameter does influence the whole coupled system, and the individual components need to be carefully adapted to each other to achieve efficient coupling. These results can have important consequences for the field of optoelectronics or polaritonic chemistry.