Injection locking of a broad-area diode laser through a double phase-conjugate mirror

Abstract Injection locking of a 1-W broad-area diode laser was achieved using a double phase-conjugate mirror (DPCM). The DPCM was build up for the first time using the broad-area laser beam and it coupled an elliptical-shaped beam of a single-mode master laser efficiently into a broad-area laser's slit-shaped output facet. Single longitudinal mode operation up to 550 mW output was achieved by an injection beam power of no more than 0.6% of the whole output. The lateral beam pattern was also improved and the measured M 2 value of the locked beam greatly decreased compared with that of the free-running beam. M 2 =8 for low-power operation and M 2 =28 for high-power operation were achieved.