Transient Growth in Non-Hermitian Photonics

Dissipation is always present in many photonic systems, either due to the inherent material losses or due to radiation outcoupling. However, in the context of non-Hermitian photonics [1], complex structures can actually benefit from the existence of losses and lead to many applications [2]. In another unrelated direction, that of fluid mechanics and turbulence, the existence of particular initial conditions that drive a linearly stable nonlinear system out of stability has led to the interesting physics of transient growth [3], [4]. Apart form few works that focus on stability issues of nonlinear optical systems, such notion is still unexplored in photonics [5], [6].