Photon Avalanche in Tm-Doped Nanocrystals: Towards Environmental and Magneto-Optical Sensing

Kevin Kwock, Columbia University

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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 1064nm CW 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 optical-based sensing techniques. Currently, we hypothesize that the spectral Zeeman splitting occurring within the energy levels of the Tm ions could be the primary origin of B-field dependence photoluminescence in ANPs. While a 42.7 GHz Zeeman splitting at 3T fields has been observed in Tm compounds, even small perturbations at GHz frequencies are expected to lead to large changes in ANP luminescent intensities. We aim to quantify and understand the B-field dependence on ANP luminescence, with the potential for establishing a new class of all-optical local magnetic sensors capable of sensitively reporting on nanoscale variations in fields. We will report on our progress and collaboration across the three institutions, including our current efforts to carry out magneto-optical and THz-dependent photoluminescence studies on ANPs at CINT.

Abstract Author(s): Kevin W.C. Kwock(1,4), Changhwan Lee(2), Artiom Skripka(3), Ayelet Teitelboim(3), Yawei Liu(3), Bruce E. Cohen(3), Emory Chan(3), Ting Shan Luk(5), Igal Brener(5), Rohit P. Prasankumar(6), Prashant Padmanabhan(4), P. James Schuck(2). (1)Department of Electrical Engineering, Columbia University, New York, NY 10027; (2)Department of Mechanical Engineering, Columbia University, New York, NY 10027; (3)The Molecular Foundry, Lawrence-Berkeley National Laboratory, Berkeley, CA 94720; (4)Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM 87545; (5)Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, NM 87123; (6)Intellectual Ventures, Bellevue, WA 98005