Ultrafast, Energy-Efficient All-Optical Switching with Plasmonic Waveguides

NTT and the Tokyo Institute of Technology (Tokyo Tech) have developed an all-optical switch that operates in the ultrafast regime with a response time in the femtosecond (fs) range and with energy consumption in the femtojoule (fJ) range. To achieve both speed and energy efficiency in the switching, the researchers combined a nanosize optical waveguide based on plasmonics with graphene. All-optical switches are expected to operate faster than switches that are electrically controlled. However, the switching energies of all-optical switches are relatively high. For ultrafast information processing, optical components need to be densely integrated in photonic circuits, and the energy consumption of each device must be low. The...