  Global quantum networks will benefit from the reliable creation and control
of high-performance solid-state telecom photon-spin interfaces. T radiation
damage centres in silicon provide a promising photon-spin interface due to
their narrow O-band optical transition near 1326 nm and long-lived electron and
nuclear spin lifetimes. To date, these defect centres have only been studied as
ensembles in bulk silicon. Here, we demonstrate the reliable creation of high
concentration T centre ensembles in the 220 nm device layer of
silicon-on-insulator (SOI) wafers by ion implantation and subsequent annealing.
We then develop a method that uses spin-dependent optical transitions to
benchmark the characteristic optical spectral diffusion within these T centre
ensembles. Using this new technique, we show that with minimal optimization to
the fabrication process high densities of implanted T centres localized
$\lesssim$100 nm from an interface display ~1 GHz characteristic levels of
total spectral diffusion.
