We have developed a monolithically integrated external feedback laser utilizing a pair of stop‐cleaved double channel planar buried heterostructure lasers emitting at 1.3 &mgr;m. The external feedback is provided by the stop cleaved facet of the second cavity. A sidemode rejection ratio of 200 : 1 has been obtained with a laser having a 250‐&mgr;m cavity length and an external resonator length of 200 &mgr;m. Since both lasers are fabricated in a self‐aligned structure, this device may prove to be a powerful scheme for injection locking to reduce dynamic linewidth.