Radiation tolerance of opto-electronic components proposed for space-based quantum key distribution

Plasma in low earth orbit can damage electronic components and potentially jeopardise the scientific missions in space. Predicting the accumulated damage and understanding the components' radiation tolerance are important to mission planning. In this manuscript we report on the observed radiation tolerance of single photon detectors and a liquid crystal polarization rotator. We conclude that an uncooled Si APD could continue to operate from more than a month up to beyond the lifetime of the satellite depending on the orbit. The polarization rotator was also unaffected by the exposed dosage.