In this paper, we report on the time-dependent strain-wave-induced changes in the reflection and diffraction of a gold plasmonic grating. We demonstrate efficient excitation of strain waves using enhanced absorption at and around the surface plasmon polariton resonance. In addition, we observe that the strain-wave-induced changes in the reflection and diffraction of the grating show an approximately quadratic dependence on pump fluence when probed at a wavelength of 400 nm. We tentatively attribute this non-linear behavior to strain-induced nonlinear changes of the interband transition energy. Using a model that calculates the permittivity of the gold taking into account the d to s/p interband transition, we deduce that the interband transition energy would have to change by about 0.013 eV to account for the measured changes in reflection.

AIP Publishing
NWO ASML UvA
doi.org/10.1063/5.0070630
AIP Advances
Light-Matter Interaction

de Haan, G., Abram, E., van den Hooven, T., & Planken, P. (2022). Plasmonic enhancement of photoacoustic strain-waves on gold gratings. AIP Advances, 12(2), 025227: 1–8. doi:10.1063/5.0070630