Abstract:
In this work, we propose room-temperature plasmonic crystal based nanolaser with
low divergence emission. Usually, performance of nanolasers based on plasmonic
crystal nanocavity is a ected by a couple of issues: coupling of lasing emission to
both re
ection and transmission side of the device and multiple di racted orders of
lasing emission. In our proposed nanolaser design, we have overcome these bottlenecks
to substantially increase the emission intensity and e ciency. Our proposed structure
consists of periodic apertures in thin metallic lm. In this design, feedback action
necessary for lasing action is provided by localized hole resonance of the nanohole
array. To improve the lasing intensity and e ciency, a one dimensional photonic
crystal is incorporated on top of the metallic nanohole array. Under optical pumping,
this photonic crystal structure excites optical Tamm states in the locality of the metal
hole array. Field enhancement due to Tamm state results in pronounced ampli cation
of extraordinary transmission leading to substantially increased lasing emission in
near-IR wavelength. Moreover, the photonic bandgap of the crystal selectively guides
laser emission towards the transmission side of the device. Due to sub-wavelength
lattice period of the nanohole array, lasing emission is con ned only to the zeroth
order of di racted mode. Resonant emission through each of the holes in periodic
array interfere constructively to produce narrow-beam emission with low divergence
in the direction normal to the nanolaser surface. Besides, emission peak wavelength of
this nanolaser can be tuned in real-time by changing the angle of incidence. Moreover,
the laser emission wavelength can be engineered over a broad range of wavelength by
changing thicknesses of the photonic crystal layers.
