Spatial Ln3+-Enrichment in Nano-Phases and kinetic Pulse-Compression on Multiphoton Upconversion Pumping Toward UV Lasing Glass-Ceramics

The multiphoton upconversion of near-infrared (NIR) light into challenging UV emission is of great importance and interest for both fundamental research and advanced applications. However, the NIR-to-UV multiphoton upconversion process is inherently inefficient. In this work, a strategy is presented to enhance NIR-to-UV conversion by integrating spatial and temporal control of energy transfer (ET) in lanthanide-doped transparent materials. Through a molecular dynamics simulation-assisted glass-ceramic design approach, the spatial distance is reduced between Yb-Tm-Gd ions and accelerated their ET rates, achieving a 267-fold enhancement of UV emission at 311 nm. Furthermore, this is showed that energy depletion in intermediate excited levels and back ET can be suppressed through short pulse-width excitation, thereby increasing the proportion of UV photons in upconversion emissions from 1.61% to 38.81%. Consequently, low-threshold, room-temperature random lasing at 311 nm under 980 nm ns laser excitation is realized. These findings establish a novel design framework for developing compact solid-state UV lasers with practical applicability.