Abstract: A low-cost, data-fitting-free robust methodology configured to distinguish the coupling condition of an arbitrary resonance, applicable in one example to a micro-resonator of a multi-micro-resonator optical integrated circuit. The method includes registering the resonator cavity response to a rapid-phase shift of the on-resonance pump field. From the registered feature of the time-dependent transmission characteristic acquired with an optical detector, the sign of a difference between the values of intrinsic loss of the cavity and the coupling rate (?i??c) is directly read out, thereby resulting not only in a more accurate estimation of the intrinsic loss as compared with related art, but also in facilitating practically-realizable inspection of massively integrated photonic platforms with micro-resonators.

Abstract: A quantum receiver for decoding an optical signal includes a beamsplitter for interfering the optical signal with a local-oscillator field to generate a displaced field, and a single-photon detector for detecting the displaced field. The quantum receiver also includes a signal-processing circuit for determining, based on an electrical output of the single-photon detector, a measurement outcome. The signal-processing circuit also determines, based on the measurement outcome and a feed-forward machine-learning model, a next displacement. The quantum receiver also includes at least one modulator for modulating, based on the next displacement, one or both of the optical signal and the local-oscillator field. Like a Dolinar receiver, the quantum receiver implements adaptive measurements to reduce the error probability of the decoded symbol. The use of machine-learning reduces the latency of the signal-processing circuit, thereby increasing the number of measurements that may be performed for each received symbol.

Abstract: A quantum receiver for decoding an optical signal includes a beamsplitter for interfering the optical signal with a local-oscillator field to generate a displaced field, and a single-photon detector for detecting the displaced field. The quantum receiver also includes a signal-processing circuit for determining, based on an electrical output of the single-photon detector, a measurement outcome. The signal-processing circuit also determines, based on the measurement outcome and a feed-forward machine-learning model, a next displacement. The quantum receiver also includes at least one modulator for modulating, based on the next displacement, one or both of the optical signal and the local-oscillator field. Like a Dolinar receiver, the quantum receiver implements adaptive measurements to reduce the error probability of the decoded symbol. The use of machine-learning reduces the latency of the signal-processing circuit, thereby increasing the number of measurements that may be performed for each received symbol.