Reliable, high power laser diodes at 980 nm are the essential devices for pumping Er or Er/Yb doped fibre amplifiers. Applications where a high fibre coupling efficiency is required, demand lasers with high spatial beam quality. Tapered lasers are today one of the most interesting solution in terms of high brightness (high power with high spatial beam quality). Furthermore, a reduced temperature shift of the wavelength is important for high power optical pump applications because this implies a less stringent temperature control. New GaInAs/(Al)GaAs quantum-dot materials exhibit a high wavelength stability vs. current and temperature. Using these quantum dots as active region, we have developed index guided tapered diode laser with a small aperture (width less than 30 μm) and standard AR/HR coatings. This device showed an optical power of 1 W CW at 1.6 A at 980 nm with a M2 factor of 2.9 in the slow axis. Furthermore, we have measured a wavelength variation of 0.0075 Å/mA at 20°C with current and 1.7 Å/°C with temperature, which is weaker than typical variations of quantum well lasers. We also developed an array of seven quantum-dot lasers which emits 3 W CW at 5.7 A. Quantum well individual devices, using the same confinement layers and waveguide geometry were also developed for comparison.
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