Incidence Angle and Polarization Dependence of Photo-Induced FMR in Co/Pd Multilayers

Dependence of photo-induced FMR (phi-FMR) on incident angle of excitation and probing laser beams has been studied in a [Co (dCo = 0.78 nm) / Pd (dPd = 0.81 nm) ]5 multi-layer film with the aim to find experimentally the limitation of inducement and detection of magnetization dynamics with oblique light incidence. We have found, in the experiments changing the incident angle of a pump beam, that phi-FMR is observed up to the grazing incident angle of 88 degrees with p-polarized excitation pulses, whereas it disappears at the incidence angle of around 65 degrees with s-polarized excitation. As for the experiments changing the incident angle of a probe beam, phi-FMR disappears at the incidence angle of 65 degrees for both s- and p-polarizations, whereas it reappears with further increasing the angle for the p-polarization and vanishes at 75 degrees.