Enhanced Multiphoton Upconversion in Single Nanowires by Waveguiding Excitation

40-Fold enhancement of upconversion luminescence in a single NaGdF4–LiF hybrid nanowire is reported, along with a series of unique characteristics. These include four-photon upconversion from Er3+:2P3/2 excited state, a low excitation power threshold, and high optical-imaging resolution by waveguiding excitation compared to free-space spot excitation. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.