Patent ID: 8363688

Claim:
An edge emitting semiconductor laser comprising a semiconductor body having a waveguide region, wherein, the waveguide region has a lower cladding layer, a lower waveguide layer, an active layer for generating laser radiation, an upper waveguide layer and an upper cladding layer, the waveguide region has at least one structured region for mode selection in which a lateral fundamental mode of the laser radiation experiences lower losses than the laser radiation of higher laser modes, the at least one structured region comprises at least one trench which extends from a top side of the semiconductor body into the upper cladding layer, the at least one trench has a depth such that no more than 300 nm of the upper cladding layer remain below a deepest location of the at least one trench, and wherein the at least one trench has a variable depth that decreases from an edge region toward a central region of the waveguide region.