Surface plasmon lasers: sources of nanoscopic light

The use of metals for light localization in lasers is a new way of reducing their size and addresses the key issues of electrical contacting and heat sinking. Such lasers can also be reduced in size almost indefinitely by accessing light that couples to collective electron oscillations of the metal, known as surface plasmons. The sizes of these optical excitations are now tantalizing close to those of solid state electronic wave-functions. Surface plasmon lasers have the potential to generate intense optical fields and accelerate light-matter interactions for extremely sensitive nanoscale spectroscopies. This review outlines the science of surface plasmon confinement and the techniques necessary to integrate semiconductors with metal nanostructures for surface plasmon amplification.