Nonlinear Optics and Photon Avalanche in Tm3+-Doped Nanocrystals: Towards Environmental Sensing in the Near-Field
Kevin Kwock, Columbia University
Tm ions have well-known energy levels spectroscopists often exploit for the study of fundamental photophysical properties in lanthanide systems. In our study, Tm-based avalanching nanoparticles (ANPs) were excited with a 1064 nanometer continuous wave laser and demonstrated substrate-dependent and environment-dependent upconversion power thresholds at which photon avalanching occurs. The heterogeneity of single ANPs emission was studied within this context and will be discussed. Furthermore, this initial study on single-particle ANPs motivates our continuing efforts to develop nanoscale materials relevant to nano-optical-based sensing techniques. We will report on our progress and collaboration across the three institutions, including our current efforts to carry out magneto-optical and other photoluminescence studies on ANPs at the Department of Energy's Center for Integrated Nanotechnologies. I will discuss this study and other advanced developments of near-field microscopy protocols, showcasing the collaborative projects I participated in during my tenure as a DOE NNSA LRGF fellow.