Enhanced Five-Photon Photoluminescence in Subwavelength AlGaAs Resonators

Multiphoton processes of absorption photoluminescence have enabled a wide range of applications including threedimensional microfabrication, data storage, and biological imaging. While the applications of two-photon and three-photon absorption and luminescence have matured considerably, higher-order photoluminescence processes remain more challenging to study due to their lower efficiency, particularly in subwavelength systems. Here, we report the observation of five-photon luminescence from a single subwavelength nanoantenna at room temperature enabled by the Mie resonances. We excite an AlGaAs resonator at around 3.6 mu m and observe photoluminescence at around 740 nm. We show that the interplay of the Mie multipolar modes at the subwavelength scale can enhance the efficiency of the five-photon luminescence by at least 4 orders of magnitude, being limited only by sensitivity of our detector. Our work paves the way toward applications of higher-order multiphoton processes at the subwavelength scales enabled by the physics of Mie resonances

Automated summary

Multiphoton processes of absorption photoluminescence have found diverse applications ranging from threedimensional microfabrication to biological imaging. However, studying higher-order photoluminescence processes at subwavelength scales has been challenging due to their low efficiency. In this study, we demonstrate the observation of five-photon luminescence from a single subwavelength nanoantenna at room temperature, enabled by the Mie resonances. The interaction of Mie multipolar modes at the subwavelength scale enhances the efficiency of five-photon luminescence by at least 4 orders of magnitude.