Radiation tolerance enhancement of silicon photonics for HEP applications

Silicon photonics modulators and photodiodes are being investigated for use in optical links for High Energy Physics experiments. In order to withstand the harsh environment in the innermost detector regions of the Large Hadron Collider at CERN and in future High Energy Physics experiments beyond the Large Hadron Collider, components will have to be resistant against extreme levels of radiation. First, we show that Mach-Zehnder modulators, which lost their functionality after X-ray irradiation, can be fully recovered by applying a forward bias after irradiation. Devices irradiated and recovered withstand the same TID when re-irradiated. Furthermore, it is presented that by applying a forward bias already during irradiation, the irradiation-induced degradation can be compensated. The possibility of device recovery could lead to a tremendous increase of radiation resistance of the optical links. Additionally, the resistance against displacement damage and ionizing radiation of silicon germanium photodiodes is presented.