Silicon bidirectional-pumping-assisted multiplexing single-photon sources with high count rates

High-probability single-photon sources are key to the development of quantum technologies, and spatial multiplexing presents a promising approach to enhancing their performance. In this work, we demonstrate a bidirectionally pumped spatial-multiplexed source based on a CMOS-compatible silicon spiral waveguide, which effectively halves the number of sources required compared to conventional unidirectional systems. Furthermore, a dual-port RAM FIFO module was designed to implement a highly stable control logic. Under both pulsed and CW pumping regimes, we experimentally characterized the enhancement in the coincidence count rate (CCR) and the coincidence-to-accidental ratio (CAR), observing a CCR gain of 1.67. Our work confirms the viability of bidirectional spatial multiplexing on silicon photonic platforms and improves the scalability of spatially multiplexed single-photon sources.