Room-Temperature Gate Voltage Modulation of Plasmonic Nanolasers.

Stable electrical modulation of plasmonic nanolasers is achieved on a hybrid graphene-insulator-metal (GIM) platform at room temperature. To support surface plasmon polariton (SPP) resonance, a zinc oxide (ZnO) nanowire is placed on the GIM platform to create a plasmonic cavity with a compact mode volume of 2.6 × 10 -2 λ 3 , and the graphene layer is used as a transparent electrode for electrical modulation. When a gate voltage is applied, the surface electron density of Al varied, which results in the shifting of its plasma frequency and thus affects its SPP dispersion. In particular, this variation strongly changes the internal loss of the SPP mode; thus, the lasing thresholds of the ZnO nanowire plasmonic nanolasers on the GIM platform can be modulated by the gate voltage. This study demonstrates the gate voltage modulation of ZnO nanowire plasmonic nanolasers on a GIM platform at room temperature. These nanolasers can exhibit ultrahigh modulation speed on the order of terahertz. Accordingly, plasmonic nanolasers with gate voltage modulation have high potential for plasmonic circuit applications with high operation speed and versatility.