LASER FORMATION OF LUMINESCENT TRACKS IN BISMUTH-DOPED NANOPOROUS GLASS

The formation of microtracks in the volume of porous glass samples by femtosecond laser pulses which is of importance for laser writing of active optical waveguides was studied. It was found that impregnation of nanoporous glass in bismuth nitrate solution leads to the appearance of an orange luminescence band under 488 nm light excitation and this luminescence band is enhanced in the laser-wriiten tracks. It is shown that increasing the laser pulse energy to 200 nJ allows increasing the phase contrast of the tracks laser-written in nanoporous glass doped with bismuth compared to the ones formed in nanoporous glass without additives.