Er-doped high-index materials for compact, on-chip devices

摘要

Er-doping of high-index materials for compact on-chip optical devices are investigated. Two sets of materials, SiNx and ErxY2−xSiO5, are used as high-index host materials. We find that in the case of ErxY2−xSiO5, crystallization-induced surface roughness can limit the optical activation of Er and cause significant propagation loss, while in the case of SiNx, very high temperatures can be used without clustering or optical de-activation of Er. In both cases, cooperative upconversion limits the amount of Er that can be doped, with SiNx providing the lower cooperative upconversion coefficient.