Reducing the size of photonic and electronic elements is critical for ultra-fast data processing and ultra-dense information storage.
Teri Odom and colleagues, Northwestern University, USA, developed single laser devices that are the size of a virus particle and that operate at room temperature. The lasing cavity of these nanolasers is made out of Au nanoparticle dimers, structures with a 3-D bowtie shape. These are supported by an organic gain material. The Au nanostructures support localized surface plasmons – collective oscillations of electrons – that have no fundamental size limits when it comes to confining light. Transient absorption measurements confirmed ultrafast resonant energy transfer between photoexcited dye molecules and gap plasmons on the picosecond time scale.
These plasmonic nanolasers could be readily integrated into silicon-based photonic devices, all-optical circuits, and nanoscale biosensors.