Abstract
Low threshold InGaAsP/InP lasers with planar buried heterostructure were grown entirely by low‐pressure metalorganic chemical vapor deposition (MOCVD). The threshold current Ith=10 mA and the differential quantum efficiency ηd =60%, which are comparable to lasers grown by liquid phase epitaxy, were obtained. Most lasers randomly selected from one wafer have threshold currents of Ith=10–25 mA, because of high thickness uniformity of MOCVD growth. Stable fundamental transverse mode operation was also obtained up to an output power of 40 mW/facet, due to controlling the active layer width less than 2 μm.