Topological insulator vertical-cavity laser array

Topological insulator lasers are arrays of semiconductor lasers that exploit fundamental features of topology to force all emitters to act as a single coherent laser. In this study, we demonstrate a topological insulator vertical-cavity surface-emitting laser (VCSEL) array. Each VCSEL emits vertically, but the in-plane coupling between emitters in the topological-crystalline platform facilitates coherent emission of the whole array. Our topological VCSEL array emits at a single frequency and displays interference, highlighting that the emitters are mutually coherent. Our experiments exemplify the power of topological transport of light: The light spends most of its time oscillating vertically, but the small in-plane coupling is sufficient to force the array of individual emitters to act as a single laser.

Automated summary

Topological insulator lasers are semiconductor laser arrays that utilize topology to create a single coherent laser from multiple emitters. The vertical-cavity surface-emitting laser (VCSEL) array demonstrated in this study emits at a single frequency and displays interference, showcasing the mutual coherence of the emitters. This experiment highlights the power of topological transport of light, where even with most of the light oscillating vertically, the small in-plane coupling forces individual emitters to behave as a single laser.