Lasing from an electromagnetic hot spot
supported by coupled metal nanoparticles (NPs)
has been demonstrated for the first time. This
new nanolaser architecture is based on three
dimensional (3D) Au bowtie NPs supported by
an organic gain material. The extreme field
compression, and thus ultra-small mode
volume, within the bowtie gap produced laser
oscillations at the localized surface plasmon
resonance gap mode of the 3D bowties.
Transient absorption measurements confirmed
ultrafast resonant energy transfer between the
photo-excited dye molecules and gap plasmons
on the picosecond time scale.
