Continuous and discrete phasor analysis of binned or time-gated periodic decays

TL;DR

This paper revisits time-resolved luminescence decay analysis using the phasor method, deriving analytical expressions for gated configurations and discussing effects like IRF offset and decay truncation.

Contribution

It introduces new analytical expressions for discrete gate configurations and discusses modifications to phasor calibration for better decay analysis.

Findings

Derived analytical expressions for square gate configurations.

Compared phasor loci to the universal semicircle.

Provided modified phase and modulus lifetime formulas.

Abstract

Time-resolved analysis of periodically excited luminescence decays by the phasor method in the presence of time-gating or binning is revisited. Analytical expressions for discrete configurations of square gates are derived and the locus of the phasors of such modified periodic single-exponential decays is compared to the canonical uni-versal semicircle. The effects of IRF offset, decay truncation and gate shape are also discussed. Finally, modified expressions for the phase and modulus lifetimes are pro-vided for some simple cases. A discussion of a modified phasor calibration approach is presented, and illustration of the new concepts with examples from the literature conclude this work.