[摘要]：An external cavity using a binary phase grating has been developed to achieve coherent combining of five quantum-cascade lasers emitting at 4.65 mu m. The grating phase profile is designed to combine five beams of equal intensities into a single beam with a good efficiency (similar to 75%). The performances of this cavity concerning output power, stability, combining efficiency and beam quality are detailed. We report a CW combining efficiency of 66% corresponding to an output power of similar to 0.5 W with a good beam quality (M(2)<1.6). (C) 2011 Optical Society of America
