Real‐Time Thermal Imaging based on the Simultaneous Rise and Decay Luminescence Lifetime Thermometry

Abstract

The most reliable technique of remote temperature sensing considers either the rise or the decay transient of a luminescent temperature probe. Here, real‐time visible (Vis) and near‐infrared (NIR) thermal imagings based on the simultaneous measurement of the emission rise and decay of transition or lanthanide metal activator are described. A single pulse time‐gated detection method that allows the real‐time mode of the temperature measurement, the emission detection at its highest temporal intensity, and the tunability of the emission detection in terms of time delay and gate width is proposed. Cr‐ZnGaGeO4/ZnGa2O4; Er, Ho, Yb–Y2O3 and Er, Ho, Yb–β‐NaYF4 nanoparticles that display luminescence in the Vis to NIR range (450–1200 nm) with timescales varying from 10 to 100 ms are selected. Maximum relative temperature sensitivity in Vis to Vis and NIR to NIR imaging which exceeds up to a factor of two the values obtained by the standard average lifetime method is achieved. This method applies to any lifetime‐based luminescent thermometer, opening a new avenue in designing accurate and straightforward lifetime thermal imaging systems operating in the Vis to NIR range.

Keywords

• lanthanide/transitional metal-doped nanoparticles.
• lifetime thermometry
• luminescence thermometry
• real-time thermal imaging
• time-gated detection
• Vis/NIR imaging