Plasmonic nanolasers based on graphene-insulator-metal platform

摘要

The development of laser miniaturizing is never stop; several kinds of approaches such as microdisk lasers and nanowirelasers, have been exploited to scale down the sizes of cavity by using surface plasmons in replacement of photonicresonance in the laser cavity. Graphene is a membrane with thickness of only one atom and the carrier mobility can be ashigh as about 15000 cm~2/V·s. Until now graphene has been widely used for many optoelectronics applications, for example,ultrafast photodetector, modulator, biosensor, transparent electrode and so on. As far as plasmonic laser is concerned, sincethe insulator layer on the metal structure is required to be very thin, it seems to be feasible to add a single-layered graphenein between the nanowire and metal while preserving the capability of forming surface plasmon polariton (SPP). Besides, wewould like to take advantage of good electrical property of graphene to make a plasmonic nanolaser which can bemodulated by externally applied current. By adding graphene on the insulator can form a versatile platform, calledgraphene-insulator-metal (GIM) structure, that can modulate the plasmonic wave characteristics. In this study, wesuccessfully fabricated and demonstrated the SPP nanolaser on GIM structure. The lasing threshold of ZnO nanowire onaluminum with graphene was lower than that without graphene. It was attributed to the changes of plasmon frequency ofmetal resulting from the induced electrons or holes by graphene.