High-power operation of aluminum-free ( kappa =0.98 mu m) pump laser for erbium-doped fiber amplifier

Abstract
The authors discuss the fabrication and characteristics of high-power (P/sub CW/=430 mW) InGaAs/InGaAsP/InGaP ridge waveguide lasers emitting at lambda =0.98 mu m, which is the optimum wavelength for pumping erbium-doped fiber amplifiers. In the past, high-power operation of Al-free pump lasers has been limited to 150 mW because of catastrophic optical damage of the mirror facet. This problem has been largely removed by increasing the spot size of the laser with the aid of an improved waveguide design. As a result, Al-free lasers can now achieve a maximum power comparable to the conventional GaAlAs-based pump lasers for lambda =0.98 mu m.