Migrating photon avalanche in different emitters at the nanoscale enables 46th-order optical nonlinearity

Lanthanide-Doped Upconversion Nanoparticles for Super-Resolution Imaging

“…[43][44][45] Although the demonstrated resolution is only a moderate improvement compared to conventional super-resolution techniques, like STED and STORM, our proposed method holds the potential to produce a narrower PSF if we can improve the signal-to-noise ratio beyond our results in this work. Our technique can also utilize the large nonlinear response induced by the photo-avalanching effect 35,36 in UCNPs to enhance resolution, though the imaging speed would be limited by the milliseconds of photon avalanche building time. Moreover, by taking advantage of heterochromatic nonlinear responses, 46 we can circumvent multiple image acquisition procedures under differential excitation powers.…”

“…[25][26][27][28][29][30][31][32][33][34] Recently, the superlinear response of a single UCNP from the photon avalanche effect enabled sub-70 nm spatial resolution, but at the expense of imaging speed. 35,36 This work takes advantage of the dynamic nonlinearity of UCNPs to improve the achievable super-resolution of the superlinear imaging modality. We demonstrate that superlinearity in UCNP is dynamically tunable by varying excitation intensity during image acquisition.…”

Exploiting Dynamic Nonlinearity in Upconversion Nanoparticles for Super-Resolution Imaging

“…They can achieve efficient superlinearity without sophisticated techniques or high excitation power. − UCNPs are composed of a nanocrystal host and thousands of embedded lanthanide ions such as Yb 3+ , Nd 3+ , Tm 3+ , and Er 3+ . The lanthanide ions contain multiple and long-lived intermediate energy states that facilitate energy transfers, resulting in upconversion emissions ranging from near-infrared (NIR) to visible and ultraviolet. − Due to their unique optical characteristics, UCNPs have been widely used in super-resolution imaging applications. − Recently, the superlinear response of a single UCNP from the photon avalanche effect enabled sub-70 nm spatial resolution but at the expense of imaging speed. , …”

Manipulating the Injected Energy Flux via Host-Sensitized Nanostructure for Improving Multiphoton Upconversion Luminescence of Tm3+

“…Conversely, the high level of Yb 3+ content could mediate an efficient long-range energy migration/transfer to excite activator ions due to its single excited energy level . However, introducing a high concentration of active ions does not contribute to the same degree of luminescence enhancement as increasing concentration due to excited-state energy dissipation caused by adverse energy transport, such as defects, cross-talk, reverse ET . As a result, a rational structural design is significant for energy manipulation to improve UCL.…”

“…19 However, introducing a high concentration of active ions does not contribute to the same degree of luminescence enhancement as increasing concentration due to excited-state energy dissipation caused by adverse energy transport, such as defects, cross-talk, reverse ET. 20 As a result, a rational structural design is significant for energy manipulation to improve UCL. Little attention has been paid so far to increasing UV/blue UCL through dopants' spatial distribution and concentration.…”