Lanthanide-doped upconversion nanoparticles (UCNPs) are
rising
as prospect nanomaterials for constructing polarization-sensitive
narrowband near-infrared (NIR) photodetectors (PDs), which have attracted
significant interest in astronomy, object identification, and remote
sensing. However, polarized narrowband NIR photodetection and imaging
based on UCNPs have yet to be realized. Herein, we demonstrate that
NIR photodetection and imaging are capable of sensing polarized light
as well as affording wavelength-selective detection at 1550 nm by
integrating directional-Au@Ag nanorods (D-Au@Ag NRs) with NaYF4:Er3+@NaYF4 UCNPs. Monolayer and large-area
D-Au@Ag NRs polarization-sensitive plasmonic antenna films are obtained,
and the center of their localized surface plasmon resonance (LSPR)
peak is located at around 1550 nm. Experimental and theoretical results
reveal that D-Au@Ag NRs have a sharp localized LSPR peak with a dominant
scattering cross section. The UCNPs coupled with D-Au@Ag NRs exhibit
significantly enhanced and strongly polarization-dependent luminescence
with a high degree of polarization (DOP) of 0.72. The first polarization-resolved
UC narrowband PD at 1550 nm is achieved, which delivers a DOP of 0.63,
a detectivity of 1.69 × 1010 Jones, and a responsivity
of 0.32 A/W. Finally, we develop a polarized imaging system for 1550
nm with visual photoelectric detection based on the aforementioned
PDs. Our work opens up possibilities for manipulating UC and developing
next-generation polarization-sensitive narrowband infrared photodetection
and imaging technology.