Integration of GaAs waveguides on a silicon substrate for quantum photonic circuits

We report a method for integrating GaAs waveguide circuits containing self-assembled quantum dots on a Si/SiO₂ wafer, using die-to-wafer bonding. The large refractive-index contrast between GaAs and SiO₂ enables fabricating single-mode waveguides without compromising the photon-emitter coupling. Anti-bunched emission from individual quantum dots is observed, along with a waveguide propagation loss <7 dB/mm, which is comparable with the performance of suspended GaAs circuits. These results enable the integration of quantum emitters with different material platforms, towards the realization of scalable quantum photonic integrated circuits.