Progress in the realization of multi-channels waveguide-integrated photon number resolving detectors

Abstract

We present our progress in the realization of a waveguide-integrated, near-infrared, 20-channel pseudo photon number resolving architecture realized on the silicon nitride platform. Each channel consists of a space multiplexing network directing to 8 superconducting nanowire single-photon detectors connected in series. Our design focusses on minimizing splitting losses, ensuring robust response across different wavelengths in the near-infrared range and achieving low noise electrical readout. Specifically, we will report on the design of wavelengthindependent splitting elements operating in the near-infrared, the realization of low-loss fiber-to-chip coupling and detail the implementation of the cryogenic biasing and readout scheme. Our work constitutes a significant advancement towards practical multi-channel photon number resolving detectors, serving as a promising building block for scalable and high-performance quantum information processing systems.