“…While the study of PT-symmetric Hamiltonians traces to the seminal paper in 1998 [19], coherently coupled semiconductor laser arrays have been studied for more than three decades [20][21][22][23][24][25][26][27][28] for applications including high brightness beam generation [29][30][31][32], beam steering [21,27,33,34], and high bandwidth modulation [35,36]. Coupled mode theory has been used to describe the supermodes of the array [23,37,38], phase velocity matching [39], and dynamics [27,40]. However, in previous couple-mode analyses, the possibility of gain difference between the individual resonators was either not included or was implicit in a set of carrier density equations coupled to the optical field equations.…”