The fabrication and performance characteristics of single frequency integrated external cavity lasers of the coupled cavity type and the distributed Bragg reflector type are described. The active cavity section of these devices utilizes the double channel planar buried heterostructure scheme for current confinement. The lasers emit near 1.55 &mgr;m. The threshold current of these lasers is in the range 70–120 mA. cw linewidth of 7 MHz has been obtained for a 2‐mm‐long laser at an output power of 3 mW. We believe lasers with longer external cavity should exhibit lower cw linewidths.