Production of "dichroitic" diffraction gratings in glasses containing silver nanoparticles via particle deformation with ultrashort laser pulses

Abstract

By repetitive irradiation of pico- or femtosecond laser pulses on glasses containing silver nanoparticles, dichroitic areas can be produced with different optical properties depending on the actual irradiation parameters. This effect, which is nanoscopically caused by permanent deformation of the initially spherical particles to non-spherical shapes and an additional formation of a halo of very small particles, is studied as a function of polarization and number of the applied pulses using two different laser systems (Ti:sapphire, λ=400 nm, tp=150 fs; Nd:YLF, λ=523.5 nm, tp=4 ps). A very special diffraction grating produced by this local deformation, which has strongly polarization- and wavelength-dependent features, is introduced and discussed.