Phase locking of a two-dimensional laser array by controlling the far-field pattern

Abstract

We report phase locking of a two-dimensional laser array through beam control in the far field of the emitters. Compared to the near-field techniques, the far-field approach involves simpler beam profiles and does not rely on having a large number of emitters in a perfectly periodic structure. Our experimental results and computer simulation also point to much higher feedback efficiency, less sensitivity to power variations among the emitters, and the ability to repair a missing element.