Inhomogeneous pumping of semiconductor lasers by contact profiling

We have demonstrated a simple yet versatile lithographic method to achieve any desired current density profile, both transversely and longitudinally. We have shown experimental results on broad area semiconductor lasers which confirm that the current density is significantly altered in the transverse direction and that the variation in the longitudinal direction is small. We emphasise that such a contact needs only a single voltage supply; all features are in electrical contact, and during operation the entire contact is maintained at the same electrical potential.