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Download fileHighly Polarized Upconversion Emissions from Lanthanide-Doped LiYF4 Crystals as Spatial Orientation Indicators
journal contribution
posted on 12.11.2021, 21:06 authored by Ze-Yu Lyu, Hao Dong, Xiang-Fei Yang, Ling-Dong Sun, Chun-Hua YanPolarized
emission, an inherent characteristic that correlated
with structure and morphology, is very sensitive to orientation. For
the upconversion (UC) emission of lanthanides, the mechanism of polarization
is rarely discussed, and the highly polarized UC emissions are poorly
developed. Herein, with the benefit of the strong anisotropic crystal
field, well-resolved emissions from lanthanide-doped LiYF4 crystals were studied, and highly polarized UC emissions from Er3+ and Ho3+ were investigated. With multiple sub-energy
level transitions, the UC emissions are classified into two sets,
with transition dipoles being either parallel or perpendicular to
the c-axis of the LiYF4 crystal. An optical
three-dimensional orientation sensor was further investigated, in
which the in-plane angle is referenced from the orientation of the
transition dipoles. In contrast, the out-of-plane angle can be deduced
from the change in the degree of polarization. This research deepens
our understanding of the polarized photoluminescence, and it opens
up an avenue toward unique UC orientation sensors.