A superconducting nanowire avalanche photodetector (SNAP) with improved high-speed performance. An inductive element may be coupled in series with at least two parallel-coupled nanowires. The nanowires may number 5 or fewer, and may be superconducting and responsive to even a single photon. The series inductor may ensure current diverted from a photon-absorbing nanowire propagates to other nanowires and become amplified. The series inductance may be less than 10 times the nominal inductance per nanowire, and may also be larger than a minimum inductance to avoid spurious outputs in response to a photon absorption. The series inductance may be configured to achieve a desired tradeoff between SNAP reset time and spurious outputs. For example, the series inductance may be configured achieve minimum reset time or maximum bias margin, subject to user-defined constraints. By appropriately configuring the series inductance, a systematic method of designing improved SNAPs may be provided.