Nanobowtie-Integrated Dielectric Mode Moiré Photonic Crystal Nanolasers.

Enhancing light-matter interactions at the nanoscale is vital for photonic devices, driving new strategies for subwavelength optical confinement. Moiré superlattices offer an attractive platform for light trapping and manipulation. However, previously demonstrated moiré-lattice lasers have predominantly relied on air modes with low modal gain. A high-quality flatband dielectric mode for single-mode and low-threshold nanolasers has rarely been explored. Here, to enhance gain utilization, we propose a one-dimensional nanobowtie-integrated moiré flatband photonic crystal nanocavity, enabling a tightly localized dielectric mode with an ultrasmall mode volume (0.1(λ/n)3) and a high quality factor (4.7 × 104). Low-threshold, single-mode emission is achieved in a device with a 30 nm bowtie gap. This work presents a practical route toward high-performance on-chip light sources for high-density photonic integrated circuits and provides a promising approach to study nanoscale light-matter interactions.