Modulation of luminescence intensity in anisotropic crystals under excitation by ultrashort pulses

Spatially periodic structures, under femtosecond pulsed excitation of crystals

“…The situation becomes more intricate in the region where the pulses overlap since the resulting light polarization will progressively rotate from one pulse's polarization to the other's, thus inducing a time modulation of the excitation probability (it is the time integral of this probability that matters at a given point in space). This situation was theoretically analyzed in [4], yielding the following result: one should observe a spatially periodic modulation of the luminescence intensity, localized in the region where the two pulses overlap. The contrast of such oscillations is maximum when the pulses are polarized at 45° with respect to the absorbing defect dipole (quite close to our experimental situation).…”