Electrically Tunable and Reconfigurable Topological Edge State Lasers
We report an actively tunable topological edge mode laser in a one dimensional Su Schrieffer Heeger (SSH) laser chain, where the SSH chain is realized in an electrically injected Fabry Perot (FP) laser array. A non Hermitian SSH model is developed to investigate the SSH laser chain with tunable active topological defect. We theoretically demonstrate topological edge mode phase transition in the SSH laser chain. The phase transition manifested in the tight binding SSH laser chain is observed experimentally and agreed well with the theoretical predictions. Finally, by electronically tuning the gain and loss waveguides, a lossy topological mode is obtained, and trivial bulky mode lasing is experimentally observed. This work presents a versatile platform to investigate novel concepts, such as parity time (PT) symmetry and topological mode, for main stream photonic applications.