Fig. 1: Design principles of a 1D topological microcavity.
From: Perovskite quantum dot one-dimensional topological laser
a Schematic of a one-dimensional (1D) topological microcavity formed by interfacing two photonic crystals (PC1 and PC2) composed of alternative high index (HI) and low index (LI) layers. The inversion center of PC1 is chosen to be within the LI layer, while the inversion center of PC2 is within the HI layer, as highlighted by the green boxes. b The calculated optical band structures of PC1 and PC2 are identical but have distinct Zak phases. The normalized electric field distributions along the z-axis within the respective unit cells for the first two optical bands are shown in the insets. c Calculated transmission spectra of the 1D topological cavity formed by 10 unit cells on each side of the interface, showing the appearance of a high-Q interface state within the optical bandgap. d Calculated spatial distribution of the electric field within the microcavity.
