Transfer-print integration of GaAs p-i-n photodiodes onto silicon nitride photonic integrated circuits

We demonstrate the integration of GaAs p-i-n photodiodes onto silicon nitride grating couplers by means of transfer-printing. Dark currents below 20 pA and waveguide-coupled responsivities of 0.30 A/W are obtained. The detectors are integrated with an on-chip near-infrared spectrometer.