  Time-resolved photoluminescence (PL) is commonly used to track dynamics in a
broad range of materials. Thus, the search for simplification of the
acquisition of PL kinetics attracts continuous attention. This paper presents a
new robust and straightforward approach to the measurement of PL decay, which
is based on randomly fluctuating excitation intensity. The random excitation
waveform is attained by using laser speckles generated on a rotating diffuser.
Owing to this, the presented technique is able to utilize any coherent
excitation source without the necessity to generate short pulses or to
controllably modulate the light. PL decay can be computationally reconstructed
from the Fourier image of the PL trace. The paper demonstrates the performance
of the method, which is able to acquire sub-microsecond dynamics as the impulse
response function reaches 300 ns. The reconstructed PL decays were compared to
streak camera measurements to verify the method. Finally, potential limitations
and applications of the technique are discussed.
