  Hypothetical oscillations of probe photons into axion-like particles might be
revealed by exploiting the strong fields of high-intensity laser pulses.
Considering an arbitrary plane-wave background, we determine the polarization
tensor induced by the quantum fluctuations of the axion field and use it to
calculate how the polarimetric properties of an initially linear-polarized
probe beam are modified. We find that various experimental setups based on
contemporary facilities and instrumentation might lead to new exclusion bounds
on the parameter space of these particle candidates. The impact of the pulse
shape on the discovery potential is studied via a comparison between the cases
in which the wave is modulated by a Gaussian envelope and a $\sin^2$ profile.
This analysis shows that the upper limits resulting from the ellipticity are
relatively insensitive to this change, whereas those arising from the rotation
of the polarization plane turn out to be more dependent on the field shape.
