Beam quality degradation processes in tapered lasers and DBR tapered lasers

We report on the mechanisms leading to beam quality degradation in conventional and DBR tapered lasers at high operating powers. The simulations were performed on ELoD2 975nm DBR tapered lasers using an in-house laser simulation tool, Speclase. We show how light propagating outside the ridge waveguide leads to beam quality degradation, showing both how the absorption in this region is bleached and where the forward propagating light comes from - even when the rear facet is anti-reflection coated.