Interfacing superconducting nanowire single photon detectors with cryogenic opto-electronics for quantum photonic applications

Abstract: Interfacing single-photon detectors with active photonic components is a cornerstone photonic quantum technology. We describe how the output signal of commercial superconducting nanowire single-photon detectors can be used in situ to drive photonic components such as lasers and electro-optic modulators, co-located in the cryostat. This is enabled by developing custom circuitry using cryogenic-compatible discrete components in the SiGe-BiCMOS platform. We have demonstrated this with a number of experiments, in particular optical readout of an SNSPD and low-latency feed-forward modulation based on single-photon measurement events, all at or below 4 K. This manuscript is an abridged version of the Master thesis of the primary author N. Lamberty.