Low-threshold ridge-waveguide 1.3-μm laser

A description is given of the fabrication and of the main properties of 1.3-μm GaInAsP lasers with a ridge (rib) waveguide structure used for lateral confinement of transverse modes and of the current. Such lasers were made by the method of ion-beam etching and self-alignment photolithography. Narrow ridges (3–5 μm) formed in this way carried Ti–Au Schottky contacts. These lasers were simple to fabricate and their threshold currents were comparable with those in much more complex lasers with buried waveguide structures.