On the role of excitation pulse duration on luminescence measurements

Abstract

Described here is an investigation into the effects of excitation pulse duration on the temporal character of luminescence of three characteristic thermographic phosphors: Mg4FGeO6:Mn, La2O2S:Eu, and YAG:Dy. Attention is first given to the build-up of the emission while the excitation pulse is on and its relation to temperature. Next, effects after pulse termination are addressed. For emission comprised of two or more characteristic decays, increasing the pulse duration will enhance the longer components relative to the shorter. For La2O2S:Eu, increasing the duration increases emission of successively longer-lived emitting states; and they display pronounced temperature dependence. For YAG:Dy, as excitation duration is increased, the main decay component used for thermometry is enhanced relative to two shorter components of less interest.

Quantitative and Multiplexed Chopper-Based Time-Gated Imaging for Bioanalysis on a Smartphone

“…A mathematical model for the operation of the double chopper was derived, drawing on prior work by others , (see Supporting Information for details). It showed that the maximum TG emission signal intensity was a compromise between competing factors: faster chopper speeds decreased the delay time and increased the number of TG cycles per image to increase the signal, whereas slower chopper speeds increased the excitation pulse duration and the integration time per TG cycle to increase the signal.…”

Parametric study of intensity-ratio-based phosphor thermometry using Mg4FGeO6:Mn4+ for instantaneous temperature measurement

“…Despite these efforts, the effects of the excitation and acquisition parameters for intensity-ratiobased phosphor thermometry remain poorly understood. For example, variations in the excitation parameters (pulse energy, wavelength and pulse width) can lead to temperature measurement errors for lifetime-based phosphor thermometry [24][25][26]. However, these excitation effects remain unclear for the intensity-ratio-based method.…”

A summary of new developments in phosphor thermometry

“…The influence of the excitation process on the luminescence emission of phosphors is studied in two other papers. In Allison [10], the effect of excitation pulse duration on the photoluminescence properties of phosphors is investigated. Three different phophors, Mg 4 FGeO 6 :Mn, La 2 O 2 S:Eu, and YAG:Dy were excited by diode laser pulses at different wavelengths in the µs to ms range and the temporal emission characteristics are recorded by a photomultiplier.…”