| dc.description.abstract | In this paper ,we selected the organic material F8BT,which has dual absorption peaks,as the active layer of the resonant cavity to construct a Ultra-strongly coupled cavity structure. In this setup , the active layer functions as both the photon and exciton source . This design allows us to fabricate devices with increased coupling strength,enabling a detailed investigation of the underlying physical phenomena . When photons and excitons within the resonator couple , they from a hybrid state particle composed of light and matter , exhibiting bosonic characteristics , known as a polariton . In resonators with a dual-peak active layer , the coupling leads to the formation of new energy branches , referred to as the upper、middle and lower branches . When the photon and exciton energy states in the resonator align , the energy difference between the upper and lower branches is called the Rabi splitting . If the Rabi splitting exceeds 20 % of the exciton energy , the resonator is considered to have achieved strong coupling .
Before the experiment begins , we utilize the optical thin film design software Macleod to simulate the thickness of each layer , ensuring the lower branch correctly aligns with the photoluminescence (PL) position of F8BT , and to model the thicknesses of high and low refractive index materials in the Distributed Bragg Reflector (DBR) mirrors . We use resonators with different mirrors to explore their effects on coupling characteristics , where the central wavelength of the DBR mirrors is designed at 515 nm , and the high reflectance bandwidth only covers the single absorption peak of F8BT . The results show that resonators with different mirrors can achieve a coupling strength of about 30 % , indicating strong coupling . By exciting the DBR resonators with light sources of varying powers , we observe that as power increases , the energy on the spectrum concentrates towards lower angles , exhibiting characteristics similar to those of a laser . | en_US |