Electronically Controlled Two-Dimensional Steering of In-Phase Coherently Coupled Vertical-Cavity Laser Arrays

Photonic crystal vertical-cavity surface-emitting laser arrays can be designed to lase only in the in-phase array supermode. By electronically addressing the array elements independently, the relative phases between the emission from each element can be altered. The shift in relative phase results in the angular deflection of the central peak of the in-phase array supermode. We demonstrate highly controllable steering of a coherent laser beam produced by a 2 2 array of emitters.