Constructing Deep Ultraviolet Microlasers through Photon Upconversion in Heavily-Doped Nanocrystals

Description

Deep ultraviolet (UV) lasers are essential for enormous use ranging from medical and life science to environmental and industrial applications. Conventional deep UV lasers reliant on gas discharge and high-order harmonic generation are large in size, expensive in cost, and difficult to operate. These drawbacks largely limit applications of these technologies in many scenarios. Semiconductor lasers hold the potential for miniaturization. However, it is unlikely to achieve deep UV lasing solely based on semiconductors, because no method is available to fabricate high-quality wide-bandgap semiconductor materials. Herein, we propose to develop a class of nanostructured materials comprising high concentration of lanthanide dopants for performing photon upconversion lasing. The design combines the advantage of the sophisticated semiconductor technology and unique photon upconversion property of lanthanide ions. The heavily doped nanocrystals are expected to enhance the absorption of pumping light, and subsequently generate intense upconverted emission in shorter wavelengths. Careful optimization of hierarchical core-shell structures coupled with design of innovative excitation schemes will be utilized to alleviate concentration quenching in the nanocrystals. Once refined, we envisage that our study may deepen our understating of lanthanide luminescence and revolutionize the fabrication of cost-effective and miniaturized solid-state lasers operating at short wavelengths.