Laser-Induced Optical Property Changes Inside Bi-Doped Glass

We report an unusual phenomenon of optical properties changes in Bi-doped glass under irradiation with a femtosecond laser. Not only broadband absorption in the visible but also infrared luminescence variations have been observed after irradiation. This behavior is related to the process of laser initiating local chemical reactions involving multiple active centers of Bi. This phenomenon provides a convenient method for 3-D selective fabrication by ultrashort laser pulses, and applications in ultrahigh density optical memory and micro photonics.