Abstract
Nanowire lasers are promising as ultra-small, highly-efficient coherent light emitters in the context of
nanophotonics, nano-optics and nanobiotechnology. Although there have been several demonstrations
of nanowire lasers utilizing homogeneous bulk gain materials, it is crucial to incorporate lowdimensional
quantum nanostructures into the nanowire so as to achieve superior device performance
with respect to threshold current, modulation bandwidth and temperature sensitivity. The quantum dot is
a useful and essential nanostructure that can meet these requirements. However, difficulties in forming
stacks of quantum dots in a single nanowire hamper the realization of lasing operation. Here, we
demonstrate for the first time room-temperature lasing in a single nanowire with 50 quantum dots by
properly designing the nanowire cavity and tailoring the emission energy of each dot to enhance the
optical gain. Our demonstration paves the way toward ultra-small lasers with extremely low-power
consumption for integrated photonic systems and bio/environmental sensing.
