  We discuss how Raman spectra of high temperature superconducting cuprates are
affected by nearly-critical spin and charge collective modes, which are coupled
to charge carriers near a stripe quantum critical point. We find that specific
fingerprints of nearly-critical collective modes can be observed and that the
selectivity of Raman spectroscopy in momentum space may be exploited to
distinguish the spin and charge contribution. We apply our results to discuss
the spectra of high-T_c superconducting cuprates finding that the collective
modes should have masses with substantial temperature dependence in agreement
with their nearly critical character. Moreover spin modes have larger masses
and are more diffusive than charge modes indicating that in stripes the charge
is nearly ordered, while spin modes are strongly overdamped and fluctuating
with high frequency.
