We present an algorithm which is capable of resolving the spectrum of
rates for decay kinetics whose elementary processes follow a first-ord
er law. The stability of the results are illustrated via Monte Carlo a
nalysis of the statistics when trying to reconstruct complex multi-mod
al distributions of the rates. Additionally, we document the successfu
l application to experimental data for a photochromic isomerization re
action in a polymeric matrix, which allows for acquiring several thous
ands of points in time at a noise level of less-than-or-equal-to 0.1 %
for the normalized absorption signal. For the first time, different c
is-trans conformations of the transient merocyanine species are shown
to have distinct kinetic behaviours regarding the decolouration proces
s without biasing the decay analysis.