Non-Hermitian gauged topological laser with multi protected modes.

A topological laser array based on the non-Hermitian Su-Schrieffer-Heeger chain of coupled microring resonators will be presented. Based on the theory of the active and passive microrings in each unit cell, a PT-symmetry structure where the edge states can be protected and the imaginary gauge field cause delocalize light between the microrings will be presented.