1550-nm light amplification from erbium-doped silica glass waveguide written by femtosecond laser pulses

Abstract

Waveguides were written in Er-doped silica glasses by femtoscecond laser pulses. The waveguides exhibit a single mode at 632.8 nm with Gaussian profile and low propagation losses (<1dB over 4.8 mm). The optical properties like insertion losses and induced refractive index changes were measured and discussed. The optical gains at 1540 nm were measured as an active element in a standard waveguide amplifier setup. A maximum of 1dB internal gain at 200 mW, 976 nm pump were obtained.