Strong coupling of single quantum dots with low-refractive-index/high-refractive-index materials at room temperature

Strong coupling between a cavity and transition dipole moments in emitters leads to vacuum Rabi splitting. Researchers have not reported strong coupling between a single emitter and a dielectric cavity at room temperature until now. In this study, we investigated the photoluminescence (PL) spectra of colloidal quantum dots on the surface of a SiO2/Si material at various collection angles at room temperature. We measured the corresponding reflection spectra for the SiO2/Si material and compared them with the PL spectra. We observed PL spectral splitting and regarded it as strong coupling between colloidal quantum dots and the SiO2/Si material. Upper polaritons and lower polaritons exhibited anticrossing behavior. We observed Rabi splitting from single-photon emission in the dielectric cavity at room temperature. Through analysis, we attributed the Rabi splitting to strong coupling between quantum dots and bound states in the continuum in the low-refractive-index/high-refractive-index hybrid material.

Thin Metal Superlens Imaging in Nanolithography

Superlens imaging system in nanolithography can be regarded as a cascade of two F-P cavities, i.e., a superlens cavity and a dielectric cavity between superlens and introduced mask of high loss, and the transfer function of system is obtained by considering multiple reflections inside the two cavities. For the range of wavevector of interest, the typical high peak of transmission coefficient of superlens coincides with a local minimum of transmission coefficient of dielectric cavity. The peak of transfer function of system corresponds to the peak of transmission coefficient of dielectric cavity. Thin superlens imaging system in nanolithography is analyzed based on transfer function, which can be flattened by simply tuning transmission coefficient of dielectric cavity and superlens cavity. The results are further validated by Finite Element Method (FEM) simulations.