Wilson

Upconversion nanoparticles (UCNPs) are luminescent nanoparticles that can absorb two or more photons and emit a single photon of a higher energy. In contrast to two photon absorption which involve virtual intermediate states, UCNPs have real metastable excited states that allow for multiphoton absorption. UCNPs are good candidates for bioimaging due to various advantages such as deep tissue penetration, excellent biostability, low cytotoxicity, and no autofluorescence. Despite UCNP efficiency being far higher than that of two photon absorption, it is still too low for biomedical applications. I will be working on generating and characterizing energy-time entangled photons for optimizing UCNP efficiency for use as a bioimaging tool.