On-chip ultrafast all-optical transistor

The possibility of processing information with light has been the driving force behind the quest for all-optical logic gates. Leveraging silicon photonics processing technology, we show optically excited exciton-polariton condensation at ambient conditions in fully integrated metamaterial-based high-index contrast grating microcavities filled with an organic polymer. By coupling two resonators and exploiting seeded polariton condensation, we demonstrate ultrafast all-optical transistor action on a picosecond timescale and cascadability of the device concept. This paves the way for more complex ultrafast all-optical logic circuits operating at room temperature.