Abstract: The disclosure relates to a photonic integrated circuit, comprising a first waveguide on a first waveguide substrate, and a second waveguide on a second waveguide substrate. The photonic integrated circuit further comprises a resonator device with a first mirror, comprising a first layered structure on a first mirror substrate, wherein the first mirror substrate is provided by or fixed to the first waveguide substrate or the second waveguide substrate. The resonator device further comprises a second mirror that comprises a second layered structure on a second mirror substrate. The second mirror substrate is provided by or fixed to the first waveguide substrate or the second waveguide substrate. The first mirror and the second mirror form end mirrors of an optical resonator. At least a portion of the first waveguide is within the optical resonator.

Abstract: A photon-number resolving (PNR) method and system are described. A PNR detector is calibrated to generate a characteristic pulse plot for each of a plurality of unique photon numbers. A generic tail portion is also stored. A signal is then detected through the PNR detector. The signal includes at least a first pulse and a second pulse, where the second pulse at least partially overlaps with the first pulse. The first photon number of the first pulse may be determined. Then, the characteristic pulse plot that corresponds to the first photon number is subtracted from the first pulse, such that the second photon number of the second pulse may be determined with minimized interference from any signal overlap. The generic tail portion may be scaled and subtracted from any identified stray events to minimize interference of stray signals from unintended light sources.