Luminescence measurements of upconverting nanocrystals (UCNCs) dispersed in SZ2080 prepolymer being pro- cessed by direct laser writing (DLW) nanopolymerization technique are presented. Er³⁺ ions doped β-NaYbF₄ and Er³⁺,Yb³⁺ co-doped β-NaGdF₄ core and core-shell UCNCs were prepared by a thermal decomposition method. The ratio of the ²H_11/2 → ⁴I_15/2 and ⁴S_3/2 → ⁴I_15/2 emission intensities under λ = 975 nm excitation was confirmed to follow Boltzmann-type distribution in the temperature range from 20 °C to 200 °C and enabled a self-referenced optical readout of the sample temperature changes. Variation of thermally-coupled spectral bands fluorescence intensity ratio (FIR) was observed while prepolymer being processed under typical DLW conditions (1030 nm, 300 fs, 200 kHz, NA = 0.8) and E_pulse varying from below modification threshold to the optical breakdown. Average fitted temperature changes around polymerized voxel measured ∆T₁ < 30 °C within polymerization window and increases up to ∆T₂~100 °C in overexposing regime.

Date Published: 2 January 2018
PDF: 10 pages
Proc. SPIE 10456, Nanophotonics Australasia 2017, 104564F (2 January 2018); doi: 10.1117/12.2283224

Published in SPIE Proceedings Vol. 10456:
Nanophotonics Australasia 2017
James W. M. Chon; Baohua Jia, Editor(s)