XXIX Symposium "Nanophysics and Nanoelectronics" in Nizhny Novgorod, March 10-14, 2025
Photonics

Luminescence tomography of upconversion phosphors with discrete distribution

L. A. Nurtdinova^a, A. V. Leont'ev^a, E. O. Mitushkin^a, D. A. Bizyaev^a, N. I. Nurgazizov^a, A. P. Chuklanov^a, V. G. Nikiforov^a, P. A. Kosach^b, D. G. Zverev<sup>b

a</sup> Kazan Scientific Centre of the Russian Academy of Sciences
^b Kazan (Volga Region) Federal University

Abstract: Test measurements of a discrete structure model were performed using confocal optical microscopy and luminescence tomography techniques. This test structure, which has a pronounced discrete distribution of upconversion phosphor aggregates, was created using atomic force microscopy techniques. As the phosphors, we chose NaYF$_4$: Yb(18%) Er(2%), particles that were synthesized using the hydrothermal method. Their upconversion luminescence in the visible spectrum upon near-infrared laser excitation at around 980 nm makes them attractive for a wide range of bioimaging applications. Using confocal microscopy, the luminescent signal was recorded with 3D spatial resolution. The comparative analysis of post-processing algorithms applied to experimental data showed that, in the case of a pronounced discrete distribution of phosphors, accounting for the point scattering function in deconvolution processing allows both to level image artifacts and to significantly increase the accuracy of determining the size of luminescent objects.

Keywords: confocal microscopy, image deconvolution, fluorescence tomography, atomic force microscopy, upconversion phosphors, fluoride particles.

Received: 21.04.2025
Revised: 21.04.2025
Accepted: 21.04.2025

DOI: 10.61011/JTF.2025.10.61338.67-25

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