(INVITED)Direct laser writing of visible and near infrared 3D luminescence patterns in glass

We report the fluorescent properties of 3D localized structure with size near the diffraction limit induced by femtosecond direct laser writing (DLW) in Yb3+ and silver-containing phosphate glass. The homogenous dispersion of the silver ions and Yb3+ ions in the glass matrix before DLW was evidenced using photo-luminescent spectroscopy and time-resolved spectroscopy. Using high repetition rate femtosecond DLW, the inscription of 3D visible and near-infrared fluorescent patterns formed by co-localization of silver cluster and Yb3+ ions was demonstrated. The local refractive index change associated with the formation of silver clusters is dependent on the laser irradiance. Confocal micro-luminescent spectroscopy for excitation wavelength in the visible range shows efficient emission of Yb3+ only on DLW induced 3D fluorescent patterns. This finding demonstrated the ability to perform thanks to DLW laser a resonant efficient nonradiative energy transfer from silver clusters to Yb3+ and allows 3D writing of near-infrared luminescence.