Low-power Sub-diffraction Optical Data Storage Using Lanthanide-doped Upconversion Nanoparticles

The explosive production of information is a major challenge for the large data centers available and calls for new storage technologies and materials. Far-field super-resolution optical techniques show the potential for sub-diffraction 3D optical data storage towards petabyte-level single-disk capacity. However, common super-resolution approaches are limited by the high inhibition laser beam intensity, which results in high energy consumption and data bit damage. In addition, there is a lack of optically activatable materials for optical readout of sub-diffraction data. Lanthanide-doped upconversion nanoparticles (UCNPs) emit in the ultraviolet and visible upon near-infrared excitation, which facilitates photoactivation for optical data storage applications [1] , [2] . Furthermore, UCNPs have been used for low-power optical nanoscopy and can be used for readout of sub-diffraction data [3] , [4] .