GaAs-on-insulator ridge waveguide nanobeam cavities with integrated InAs quantum dots

This study investigates nanobeam cavities on a GaAs-on-insulator chip with InAs quantum dots, including design, fabrication, and experimental characterization. The nanobeam cavities are optimized for high photon coupling efficiency and pronounced light-matter coupling. Numerical studies yield Q factors up to about 1400, a coupling efficiency of nearly 70% and a maximum Purcell factor of approximately 100. Experimentally, these devices have a $Q$ factor of about 1300, and comparing the lifetime of quantum dots in on-resonance and off-resonance conditions, a Purcell factor of 10.46±0.14 is obtained. Moreover, in the single-emitter regime, we observe strong multiphoton suppression with g(2)(0) = 0.295. Our results demonstrate the high potential of nanobeam cavity on a GaAs-on-insulator platform for quantum photonic applications.