Search

InGaAs/GaInAsP/GaInP ridge waveguide 980-nm laser diodes for pumping light into erbium doped fiber amplifiers are reviewed. These lasers have very good performance characteristics. They exhibit kink-free, single mode emission up to a power of 250 mW with a slope efficiency of 0.7 to 0.95 W/A, a thermally limited maximum power of 450-500 mW, and the threshold current density of about 150 A/cm/sup 2/. They are relatively stable against temperature variations. A 100 mW power from a fiber-pigtail module has been demonstrated. These lasers withstand severe thermal rollover tests without showing degradation effects. Preliminary lifetime tests indicate that their mean-time-to-failure (MTTF) may be very long, from several hundred thousand to one million hours, if not limited by sudden failure.

In this letter, the authors report a very high quantum efficiency of 91% for antireflection/high-reflection-coated GaInP-AlGaInP ridge waveguide laser diodes operating at 650 nm range. The laser structure was grown by solid-source molecular beam epitaxy. The laser diodes performed stable single-mode operation up to 60 mW. Threshold current as low as 50 mA was measured for 5.5/spl times/600 /spl mu/m/sup 2/ laser diodes. To the authors' best knowledge, this is among the best ever reported efficiency for visible lasers.

High-performance strained-layer GaInAs-GaInAsP-GaInP separate-confinement quantum-well lasers emitting at /spl lambda/=980 nm were grown by all solid-source molecular-beam epitaxy. Valved cracker cells were employed to generate group-V beam fluxes. Fabricated ridge-waveguide lasers exhibited stable, kink-free, single-mode operation up to 260 mW. A maximum output power of 550 mW was achieved. Complete thermal roll-over tests were done tens of times without any sign of degradation for p-side up-mounted lasers. Preliminary lifetime tests for over 4500 h at 150-mW power level indicate that these aluminum-free pump lasers are very reliable sources for pumping light into erbium-doped fiber amplifiers.