All-optical multi-channel switching at telecommunication wavelengths based on tunable plasmon-induced transparency

As a plasmonic analogue of electromagnetically induced transparency (EIT), plasmon-induced transparency (PIT) has been widely studied duo to the excellent performance on sensing, slow light and enhancing nonlinear effects, which has great potential to be applied on compact optical communication system. Here, we introduce an all-optical PIT multi-channel switching based on the metal-insulator-metal (MIM) plasmonic waveguide device with small footprint. Single/double PIT is investigated both theoretically and numerically by multi-oscillator theory (MOT) and finite-difference time-domain (FDTD), and utilizing the nonlinear medium filled in the cavity, the PIT can be dynamically tunable to achieve various kinds of single/multi-channel switching for telecommunication wavelengths. Besides, utilizing the unprecedented high Kerr coefficient of graphene, the low-power and ultrafast all-optical switching can be made possible. This work provides a novel scheme to realize all-optical switching based on PIT, which can promote on-chip ultrafast optical communication and signal processing.