Upconversion photoluminescence appears to shine polarized and brighter

https://phys.org/news/2023-09-upconversion-photoluminescence-polarized-brighter.html

"dielectric metasurface amplifies upconversion emissions... utilized resonant metasurface high-Q collective modes for polarization-controlled dual-band upconversion bursts... composed of diatomic nano bricks... controlling polarization analyzer rotation demonstrated linearly- and cross-polarized emission at dual bands with ultra-high degrees polarization... efficient enhancement and polarization control of UCNP emission... low-threshold polarization upconversion lasers and hyperspectral imaging/sensing"