Active waveguide fabrication in erbium-doped oxyfluoride silicate glass using femtosecond pulses

By directly writing waveguides inside bulk erbium-doped oxyfluoride silicate glass using a focused femtosecond pulse train, we demonstrate the potential for the fabrication of especially broadband, compact telecommunications optical amplifiers operating in the c-band (1529–1561nm). Characterization results include coupling losses to single-mode fiber, waveguide losses, and gain measurements. Clear relationships between the fabrication pulse energy and the waveguide losses and coupling losses are also established.