High-temperature optical properties of sensitized Er3+ in Si-rich SiO2 – implications for gain performance

The high-temperature photoluminescence of Er-doped Si-rich SiO2 with and without silicon nanocrystals is studied at sample temperatures in the range 20–200 °C. The optical properties of Er-doped Si-rich SiO2 with and without silicon nanocrystals are shown to exhibit a similar temperature dependence. Based on the measured photoluminescence intensities and lifetimes it is predicted that an increase of the sample temperature from 20 to 200 °C results in a decrease of the maximum optical gain at 1535 nm by a factor of ∼1.8 and ∼1.6 for samples with and without silicon nanocrystals, respectively. Implementation of this material in silicon photonics requires stable operation at typical processor case temperatures up to 80–90 °C. It is demonstrated that increasing the temperature from room temperature to 90 °C leads to a predicted maximum optical gain reduction of ∼1.26 for both materials. In addition, the predicted erbium related optical gain at significant inversion levels in samples processed at low temperature (600 °C) is a factor ∼9 higher than for samples processed at high temperature (1060 °C). These findings demonstrate that relatively thermally stable gain performance of the Er-doped Si-rich SiO2 up to typical processor operating temperatures is possible and indicate that low-temperature-processed erbium-doped silicon-rich SiO2 is a technologically viable gain medium for use in silicon photonics.