Based on flip-chip technology, we demonstrate hybrid integration of a 4×1 indium gallium arsenide/indium phosphide (InGaAs/InP) single-photon avalanche diode (SPAD) array and a silicon photonic chip. When testing two SPADs in the 4×1 SPADs array simultaneously at 10 ℃, we achieve on-chip photon detection efficiency of 5%‒6% under a low bias voltage, with dark count rates of 1.6×10-5 counts/gate and 4.5×10-5 counts/gate, respectively. Increasing the bias voltage, the on-chip photon detection efficiency can be further increased to more than 10%. Furthermore, using the integrated SPAD array and silicon photonic beam splitter, we realize the measurement of Hong‒Ou‒Mandel (HOM) interference for weak coherent states, achieving a HOM interference fringe visibility of 45.0%±1.2%. This demonstrates the effectiveness of hybrid integration of the photon manipulation on the silicon photonic chip and the multi-channel single-photon detection of the integrated SPADs array. The hybrid integration provides a potential solution for achieving scalable photonic quantum information systems.
Xiaosong Ren, Yuanbin Fan, Yanli Shi, Zhiliang Yuan, Yidong Huang, Wei Zhang. Hybrid Integration of Single-Photon Avalanche Diode Array and Silicon Photonic Chip (Invited)[J]. Acta Optica Sinica (Online), 2024, 1(1): 0104001