Spectral-temporal dynamics of transient absorption of multilayer periodic plasmonic nanostructures
The features of the induced changes in the optical density spectra of multilayer Ag-Na<sub>3</sub>AlF<sub>6</sub> nanostructures under a femtosecond laser pulses exitation in the band of surface plasmonic resonance of absorption (SPRA) were studied. The de­pendence of the amplitude of the induced changes on the thickness of the dielectric Na<sub>3</sub>AlF<sub>6</sub> films separating the monolayeres of silver nanoparticles was registered. A significant increase of the optical response amplitude (up to 80 %) was found for the nanostructures with the quarter-wavelength Na<sub>3</sub>AlF<sub>6</sub> interlayers. For nanostructures with different-thickness dielectric Na<sub>3</sub>AlF<sub>6</sub> interlayers the characteristic relaxation times of induced changes at an excitation energy of 5-10 μJ do not practically vary, are equal to ~2 ps and coincide with the kinetic response time parameters of the used silver nanoparticle monolayers.