Absolute timing of the Crab Pulsar at optical wavelengths with STJs

We have observed the Crab Pulsar in the optical with S-Cam, an instrument based on Superconducting Tunneling Junctions (STJs) with $mu$s time resolution. Our aim was to study the delay between the radio and optical pulse. The Crab Pulsar was observed three times over a time span of almost 7 years, on two different locations, using three differe