Plasmonic and metallic cavity nanolasers: A new paradigm for semiconductor lasers?

Miniaturization has been an eternal theme for electronics and photonics since the dawn of the semiconductor era. Size reduction of photonic devices has been driven both by the rich physics and by promising applications in future nanophotonic systems. Micro cavity lasers have been topics of great interests for several decades in the photonics and physics communities due to their interesting photonic and quantum optical properties and their potential applications in integrated photonics systems. In the last decades, several new concepts of ever smaller lasers have been demonstrated such as photonics crystal lasers, microdisk lasers, photonic wire lasers, and nanowire lasers. While such designs and concepts have led to unprecedented size reduction of semiconductor lasers from their predecessors, further size reduction of dielectric-cavity lasers becomes exceedingly challenging when the wavelength becomes the eventual roadblock.¹ At the same time, it is becoming increasingly clear that future lasers needed for energy efficient interconnects on a computer chip requires lasers of 100s nanometer in sizes ³. Pure dielectric lasers are not likely to provide good enough optical confinement in a gain medium down to such sizes with enough gain to overcome laser threshold.