An easily fabricated high‐power index‐guided laser, the twin‐channel substrate‐mesa‐guide (TCSM) laser, has been developed for applications in recording, printing, and communications. The TCSM laser is fabricated by one‐step organometallic vapor phase epitaxy (OMVPE) on photolithographically patterned and etched substrates. Linear output characteristics were observed to 40 mW cw with corresponding operation in zero order lateral and transverse modes and no astigmatism. Stable single longitudinal mode oscillation also resulted from the strong refractive index guiding produced by the nonplanar structure.