Semiconductor nanorod plasmonic lasers: Single-nanorod and ensemble measurements

Scaling down semiconductor lasers in all three dimensions hold the key to the developments of compact, low-threshold, and ultrafast coherent light sources, as well as photonic integrated circuits. However, the minimum size of conventional semiconductor lasers utilizing dielectric cavity resonators (photonic cavities) is limited by the diffraction limit. Recently, it has been proposed and experimentally demonstrated that the use of plasmonic cavities based on metal-oxide-semiconductor (MOS) nanostructures can break this limit. In this talk, I will report on the recent progress of plasmonic nanolasers using MOS structures. In particular, by using alloy-composition-varied indium gallium nitride/gallium nitride (In
x
Ga
1−x
Ga@GaN) core-shell nanorods as the nanolaser gain media in the full visible spectrum, we are able to demonstrate allcolor nanolasers that can be operated with ultralow continuous-wave lasing thresholds and single lasing modes. Very recently, we have also succeeded in developing nanorod-array plasmonic lasers based on a metal-all-around nanorod MOS structure, which can be fabricated on a wafer scale. The group-III-nitride nanorods in these 2D arrays behave as an ensemble of random dielectric media, whereby Anderson localization of light occurs in a spatially confined area. Due to the light localization, the lasing phenomenon above the optical pumping threshold shows a strong self-focusing behavior.