  Much of the information processing performed by a neuron occurs in the
dendritic tree. For neural systems using light for communication, it is
advantageous to convert signals to the electronic domain at synaptic terminals
so dendritic computation can be performed with electrical circuits. Here we
present circuits based on Josephson junctions and mutual inductors that act as
dendrites, processing signals from synapses receiving single-photon
communication events with superconducting detectors. We show simulations of
circuits performing basic temporal filtering, logical operations, and nonlinear
transfer functions. We further show how the synaptic signal from a
single-photon can fan out locally in the electronic domain to enable the
dendrites of the receiving neuron to process a photonic synapse event or pulse
train in multiple different ways simultaneously. Such a technique makes
efficient use of photons, energy, space, and information.
