Phase conjugate self-organized coherent beam combination: a passive technique for laser power scaling

In this Letter, a first (to our knowledge) demonstration of phase conjugate self-organized coherent beam combination is reported. A demonstration involving combination of two self-adaptive gain grating holographic laser resonators is presented. Output powers of up to 27 W, with a combination efficiency of 94%, are demonstrated. This technique coherently combines individual phase conjugate laser modules, which do not have predefined spectral or spatial modes. This removes the problem of finding shared resonator modes, which should allow coherent beam combination of much larger laser arrays than standard self-organized coherent beam combination.