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

By repetitive irradiation of pico- or femtosecond laser pulses on glasses c ontaining silver nanoparticles, dichroitic areas can be produced with diffe rent optical properties depending on the actual irradiation parameters. Thi s effect which is nanoscopically caused by permanent deformation of the ini tially spherical particles to non-spherical shapes and an additional format ion of a halo of very small particles, is studied as a function of polariza tion and number of the applied pulses using two different laser systems (Ti :sapphire, lambda = 400 nm, t(p) = 150 fs; Nd:YLF, lambda = 523.5 nm, t(p) = 4 ps). A very special diffraction grating produced by this local deformat ion, which has strongly polarization- and wavelength-dependent features, is introduced and discussed.