posted on 2021-03-04, 20:08authored byHuan Chen, Meijuan Sun, Jie Ma, Baobao Zhang, Chi Wang, Lei Guo, Tao Ding, Zhenglong Zhang, Hairong Zheng, Hongxing Xu
Rare-earth-doped
upconversion luminescence has attracted extensive
attention due to its narrow-band and wide-range emission spectra,
which cover biological and optical communication windows. For direct
laser excitation, the photoluminescence of upconversion nanoparticles
is inevitably involved in the excitation laser signals to luminescence,
limiting its application due to high background noise, heating, and
the low quantum yield of rare-earth-doped upconversion photoluminescence.
Here, multiplasmons-excited upconversion luminescence was investigated
by employing propagating surface plasmons polaritons on a monocrystalline
silver microplate: pure plasmon near-field excitation without background
photoluminescence. Due to near-field excitation, multisurface plasmons
upconversion luminescence exhibit strong excited-state absorption
and energy transfer upconversion, and more than 97-fold luminescence
enhancement was obtained without background noise. It was found that
multiplasmons-excited luminescence can be easily controlled by surface
plasmons polaritons propagation and excitation modes and laser polarization
directions, and a super-resolution luminescence of upconversion nanoparticles
was achieved beyond the diffraction limit. The characterization of
multiplasmon-excited luminescence helps not only enhance the understanding
of light–matter interactions between rare-earth ions and plasmons
in the near-field, but also benefits the development of bioimaging
and the super-resolution of micro light sources.