Strong coupling between quantum dots and dielectric microdisks at room temperature

The coupling between emitters and optical microcavities is an important research topic in the field of optical physics. In this study, the strong coupling between colloidal quantum dots and dielectric microdisk cavity at room temperature was investigated. We fabricated microdisks with a low-refractive-index polymer film on a high-refractive-index substrate. Due to the destructive interference between the loss channels, quasi-bound states in the continuum are formed in our hybrid refractive index structure. Strong coupling between the quantum dots and the microcavity was achieved at room temperature by matching the quasi-bound states in the continuum of the microcavity to the exciton energy level of the quantum dots. By measuring the angle-resolved photoluminescence spectra of colloidal quantum dots, Rabi splitting energy up to 62 meV was obtained. At the same time, the photoluminescence spectra and the coupling strength of colloidal quantum dots located at different positions on the cavity were measured and analyzed.