Ridge-Riding Plasmons

摘要

Nanophotonics aims to integrate the speed of optics with the nanometer size scale of the electronics industry. The several-orders-of-mag-nitude difference in size scale of the respective components present a technological challenge to that integration. Surface plasmons, the sub-wavelength collective light-induced electronic excitations that propagate at the surface of metals, can bridge that size gap and so are an area that is being actively pursued. However, there tends to be a trade-off between how far the plasmons can propagate and the extent of their confinement. Using a silicon-on-insulator platform with a silver overlayer, Mu et al. present a simulation study showing that forming a ridge in the silicon can help relax the restrictions of that trade-off. By varying the geometry of the ridge, they show that the confinement of the plasmons can be enhanced without compromising their propagation length. The compatibility of their structure with conventional electronics processing techniques also lends itself favorably to the development of integrated optoelectronic circuits and devices.