5 W high-efficiency high-brightness tapered diode lasers at 980 nm

Tapered diode lasers in external resonator configuration are suitable for applications such as frequency conversion or non-linear spectroscopy were narrow linewidth in combination with high output power is needed. In order to increase the brightness it is necessary to make the output power and the efficiency comparable to broad area lasers and simultaneously keep the beam quality nearly diffraction limited. For this purpose we have grown low modal gain, single quantum well InGaAs/AlGaAs devices emitting at 980 nm by molecular beam epitaxy. As an example of a tapered laser with an overall length of 3.5 mm, we achieved an optical output power of more than 5 W in continuous wave mode (cw).