On-chip cascadable all-optical polariton transistors

The ability to process information using light has been the driving force behind the pursuit of all-optical logic gates. This alternative to conventional electronic transistors could define a new paradigm for computer architectures, offering exceptional speed and energy efficiency. However, until now, no proposed platform has met the three crucial requirements of operating at room temperature, providing ultra-fast switching, and being suitable for on-chip integration. By leveraging silicon-on-insulator technology, we have demonstrated integrated exciton-polariton condensation on-chip under ambient conditions, using fully integrated metamaterial-based high-index contrast grating microcavities filled with an organic polymer as the photoactive material. By coupling two resonators and exploiting seeded polariton condensation, we have achieved ultrafast all-optical transistor action and cascadability. This breakthrough paves the way for the development of more complex ultra-fast all-optical logic circuits that can operate at room temperature.