Topological insulator vertical-cavity laser array

Topologically locked for emission The output power from a laser system can be increased by forming an array of lasers; however, because the individual lasers are independent, the resultant output may not be coherent. Dikopoltsev et al . report on the realization of a topological vertical-cavity surface-emitting laser (VCSEL) array. The topological nature of the array-based laser emission was achieved through a combination of topological in-plane propagation of evanescent light linking the vertical cavity surface-emitting lasers of the array. The topological features of the array force injection locking, making all emitters (30 in this case) act as a single coherent laser. This development will be important for realizing large-scale coherent laser arrays. —ISO