GaN Magic Angle Laser in a Merged Moiré Photonic Crystal

Abstract

We demonstrate optically pumped blue lasing at room temperature in a merged moiré photonic crystal fabricated out of gallium nitride with embedded, fragmented quantum wells. Lasing occurs at two closely spaced wavelengths of 450 and 451 nm, matched to simulated flat bands induced by the moiré superlattice. Both thresholds occur at 30 μJ/cm2. Light in–light out curves were taken at both room temperature and 77 K across different gain materials, including fragmented quantum wells, continuous quantum wells, and quantum dots. Lasing was observed only at room temperature in fragmented quantum well devices, suggesting the importance of gain material carrier dynamics in unconventional laser cavities like the moiré design explored. These insights and the experimental validation of moiré simulations in a previously unexplored III–V material indicate promise toward a new kind of efficient, tunable laser.