Investigation of the suitability of silicate bonding for facet termination in active fiber devices.

We demonstrate that silicate bonding an optical flat to the output facet of an active fiber device can increase the reliability of high-peak power systems and subsantially reduce the effective feedback at the termination of a double-clad fiber. We determine the bonding parameters and conditions that maximize the optical damage threshold of the bond and minimize the Fresnel reflection from the bond. At 1-mum wavelength, damage thresholds greater than 70 J/cm(2) are demonstrated for 25-ns pulses. We also measured Fresnel reflections less than -63 dB off the bond. Finally, we determined that the strength of the bond is sufficient for most operating environments.