Multiphoton upconversion in rare earth doped nanocrystals for sub-diffractive microscopy

Summary form only given. Overcoming the spatial resolution limitations in optical microscopy due to the diffraction of light has become a major challenge in modern microscopy. To overcome this limit, we demonstrate here the upconversion process in rare-earth-doped fluoride nanoparticles (RE:NPs) that may serve as novel sources for fluorescent microscopy. RE… (More)