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

This study investigates nanobeam cavities on a GaAs-on-insulator (GaAsOI) chip with InAs quantum dots (QDs), including design, fabrication, and experimental characterization. The nanobeam cavities are optimized for high photon coupling efficiency and pronounced light-matter interaction. 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 QDs in on-resonance and off-resonance conditions, a Purcell factor of $10.46\pm0.14$ is obtained. Moreover, in the single-emitter regime, we observe strong multiphoton suppression with $g^{(2)}(0) = 0.297$ . Our results demonstrate the high potential of nanobeam cavities on a GaAsOI platform for quantum photonic applications.